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![Ahmad Fatoum](/assets/img/avatar_default.png)
For non-DMA usage, we have an easy way to associate a timestamp with a sample: iio_pollfunc_store_time stores a timestamp in the primary trigger IRQ handler and stm32_adc_trigger_handler runs in the IRQ thread to push out the buffer along with the timestamp. For this to work, the driver needs to register an IIO_TIMESTAMP channel. Do this. For DMA, it's not as easy, because we don't push the buffers out of stm32_adc_trigger, but out of stm32_adc_dma_buffer_done, which runs in a tasklet scheduled after a DMA completion. Preferably, the DMA controller would copy us the timestamp into that buffer as well. Until this is implemented, restrict timestamping support to only PIO. For low-frequency sampling, PIO is probably good enough. Cc: Holger Assmann <has@pengutronix.de> Acked-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Link: https://lore.kernel.org/r/20210125194824.30549-1-a.fatoum@pengutronix.de Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2144 lines
58 KiB
C
2144 lines
58 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* This file is part of STM32 ADC driver
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*
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* Copyright (C) 2016, STMicroelectronics - All Rights Reserved
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* Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
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*/
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/dma-mapping.h>
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#include <linux/dmaengine.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/timer/stm32-lptim-trigger.h>
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#include <linux/iio/timer/stm32-timer-trigger.h>
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#include <linux/iio/trigger.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/triggered_buffer.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/iopoll.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include "stm32-adc-core.h"
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/* Number of linear calibration shadow registers / LINCALRDYW control bits */
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#define STM32H7_LINCALFACT_NUM 6
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/* BOOST bit must be set on STM32H7 when ADC clock is above 20MHz */
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#define STM32H7_BOOST_CLKRATE 20000000UL
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#define STM32_ADC_CH_MAX 20 /* max number of channels */
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#define STM32_ADC_CH_SZ 10 /* max channel name size */
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#define STM32_ADC_MAX_SQ 16 /* SQ1..SQ16 */
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#define STM32_ADC_MAX_SMP 7 /* SMPx range is [0..7] */
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#define STM32_ADC_TIMEOUT_US 100000
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#define STM32_ADC_TIMEOUT (msecs_to_jiffies(STM32_ADC_TIMEOUT_US / 1000))
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#define STM32_ADC_HW_STOP_DELAY_MS 100
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#define STM32_DMA_BUFFER_SIZE PAGE_SIZE
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/* External trigger enable */
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enum stm32_adc_exten {
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STM32_EXTEN_SWTRIG,
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STM32_EXTEN_HWTRIG_RISING_EDGE,
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STM32_EXTEN_HWTRIG_FALLING_EDGE,
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STM32_EXTEN_HWTRIG_BOTH_EDGES,
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};
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/* extsel - trigger mux selection value */
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enum stm32_adc_extsel {
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STM32_EXT0,
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STM32_EXT1,
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STM32_EXT2,
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STM32_EXT3,
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STM32_EXT4,
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STM32_EXT5,
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STM32_EXT6,
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STM32_EXT7,
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STM32_EXT8,
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STM32_EXT9,
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STM32_EXT10,
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STM32_EXT11,
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STM32_EXT12,
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STM32_EXT13,
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STM32_EXT14,
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STM32_EXT15,
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STM32_EXT16,
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STM32_EXT17,
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STM32_EXT18,
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STM32_EXT19,
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STM32_EXT20,
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};
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/**
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* struct stm32_adc_trig_info - ADC trigger info
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* @name: name of the trigger, corresponding to its source
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* @extsel: trigger selection
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*/
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struct stm32_adc_trig_info {
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const char *name;
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enum stm32_adc_extsel extsel;
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};
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/**
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* struct stm32_adc_calib - optional adc calibration data
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* @calfact_s: Calibration offset for single ended channels
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* @calfact_d: Calibration offset in differential
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* @lincalfact: Linearity calibration factor
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* @calibrated: Indicates calibration status
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*/
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struct stm32_adc_calib {
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u32 calfact_s;
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u32 calfact_d;
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u32 lincalfact[STM32H7_LINCALFACT_NUM];
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bool calibrated;
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};
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/**
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* struct stm32_adc_regs - stm32 ADC misc registers & bitfield desc
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* @reg: register offset
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* @mask: bitfield mask
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* @shift: left shift
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*/
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struct stm32_adc_regs {
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int reg;
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int mask;
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int shift;
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};
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/**
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* struct stm32_adc_regspec - stm32 registers definition
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* @dr: data register offset
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* @ier_eoc: interrupt enable register & eocie bitfield
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* @ier_ovr: interrupt enable register & overrun bitfield
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* @isr_eoc: interrupt status register & eoc bitfield
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* @isr_ovr: interrupt status register & overrun bitfield
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* @sqr: reference to sequence registers array
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* @exten: trigger control register & bitfield
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* @extsel: trigger selection register & bitfield
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* @res: resolution selection register & bitfield
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* @smpr: smpr1 & smpr2 registers offset array
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* @smp_bits: smpr1 & smpr2 index and bitfields
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*/
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struct stm32_adc_regspec {
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const u32 dr;
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const struct stm32_adc_regs ier_eoc;
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const struct stm32_adc_regs ier_ovr;
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const struct stm32_adc_regs isr_eoc;
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const struct stm32_adc_regs isr_ovr;
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const struct stm32_adc_regs *sqr;
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const struct stm32_adc_regs exten;
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const struct stm32_adc_regs extsel;
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const struct stm32_adc_regs res;
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const u32 smpr[2];
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const struct stm32_adc_regs *smp_bits;
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};
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struct stm32_adc;
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/**
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* struct stm32_adc_cfg - stm32 compatible configuration data
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* @regs: registers descriptions
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* @adc_info: per instance input channels definitions
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* @trigs: external trigger sources
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* @clk_required: clock is required
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* @has_vregready: vregready status flag presence
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* @prepare: optional prepare routine (power-up, enable)
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* @start_conv: routine to start conversions
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* @stop_conv: routine to stop conversions
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* @unprepare: optional unprepare routine (disable, power-down)
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* @irq_clear: routine to clear irqs
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* @smp_cycles: programmable sampling time (ADC clock cycles)
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*/
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struct stm32_adc_cfg {
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const struct stm32_adc_regspec *regs;
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const struct stm32_adc_info *adc_info;
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struct stm32_adc_trig_info *trigs;
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bool clk_required;
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bool has_vregready;
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int (*prepare)(struct iio_dev *);
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void (*start_conv)(struct iio_dev *, bool dma);
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void (*stop_conv)(struct iio_dev *);
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void (*unprepare)(struct iio_dev *);
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void (*irq_clear)(struct iio_dev *indio_dev, u32 msk);
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const unsigned int *smp_cycles;
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};
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/**
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* struct stm32_adc - private data of each ADC IIO instance
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* @common: reference to ADC block common data
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* @offset: ADC instance register offset in ADC block
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* @cfg: compatible configuration data
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* @completion: end of single conversion completion
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* @buffer: data buffer + 8 bytes for timestamp if enabled
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* @clk: clock for this adc instance
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* @irq: interrupt for this adc instance
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* @lock: spinlock
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* @bufi: data buffer index
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* @num_conv: expected number of scan conversions
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* @res: data resolution (e.g. RES bitfield value)
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* @trigger_polarity: external trigger polarity (e.g. exten)
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* @dma_chan: dma channel
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* @rx_buf: dma rx buffer cpu address
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* @rx_dma_buf: dma rx buffer bus address
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* @rx_buf_sz: dma rx buffer size
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* @difsel: bitmask to set single-ended/differential channel
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* @pcsel: bitmask to preselect channels on some devices
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* @smpr_val: sampling time settings (e.g. smpr1 / smpr2)
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* @cal: optional calibration data on some devices
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* @chan_name: channel name array
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*/
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struct stm32_adc {
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struct stm32_adc_common *common;
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u32 offset;
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const struct stm32_adc_cfg *cfg;
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struct completion completion;
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u16 buffer[STM32_ADC_MAX_SQ + 4] __aligned(8);
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struct clk *clk;
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int irq;
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spinlock_t lock; /* interrupt lock */
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unsigned int bufi;
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unsigned int num_conv;
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u32 res;
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u32 trigger_polarity;
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struct dma_chan *dma_chan;
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u8 *rx_buf;
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dma_addr_t rx_dma_buf;
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unsigned int rx_buf_sz;
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u32 difsel;
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u32 pcsel;
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u32 smpr_val[2];
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struct stm32_adc_calib cal;
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char chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
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};
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struct stm32_adc_diff_channel {
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u32 vinp;
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u32 vinn;
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};
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/**
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* struct stm32_adc_info - stm32 ADC, per instance config data
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* @max_channels: Number of channels
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* @resolutions: available resolutions
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* @num_res: number of available resolutions
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*/
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struct stm32_adc_info {
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int max_channels;
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const unsigned int *resolutions;
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const unsigned int num_res;
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};
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static const unsigned int stm32f4_adc_resolutions[] = {
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/* sorted values so the index matches RES[1:0] in STM32F4_ADC_CR1 */
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12, 10, 8, 6,
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};
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/* stm32f4 can have up to 16 channels */
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static const struct stm32_adc_info stm32f4_adc_info = {
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.max_channels = 16,
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.resolutions = stm32f4_adc_resolutions,
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.num_res = ARRAY_SIZE(stm32f4_adc_resolutions),
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};
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static const unsigned int stm32h7_adc_resolutions[] = {
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/* sorted values so the index matches RES[2:0] in STM32H7_ADC_CFGR */
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16, 14, 12, 10, 8,
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};
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/* stm32h7 can have up to 20 channels */
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static const struct stm32_adc_info stm32h7_adc_info = {
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.max_channels = STM32_ADC_CH_MAX,
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.resolutions = stm32h7_adc_resolutions,
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.num_res = ARRAY_SIZE(stm32h7_adc_resolutions),
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};
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/*
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* stm32f4_sq - describe regular sequence registers
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* - L: sequence len (register & bit field)
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* - SQ1..SQ16: sequence entries (register & bit field)
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*/
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static const struct stm32_adc_regs stm32f4_sq[STM32_ADC_MAX_SQ + 1] = {
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/* L: len bit field description to be kept as first element */
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{ STM32F4_ADC_SQR1, GENMASK(23, 20), 20 },
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/* SQ1..SQ16 registers & bit fields (reg, mask, shift) */
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{ STM32F4_ADC_SQR3, GENMASK(4, 0), 0 },
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{ STM32F4_ADC_SQR3, GENMASK(9, 5), 5 },
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{ STM32F4_ADC_SQR3, GENMASK(14, 10), 10 },
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{ STM32F4_ADC_SQR3, GENMASK(19, 15), 15 },
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{ STM32F4_ADC_SQR3, GENMASK(24, 20), 20 },
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{ STM32F4_ADC_SQR3, GENMASK(29, 25), 25 },
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{ STM32F4_ADC_SQR2, GENMASK(4, 0), 0 },
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{ STM32F4_ADC_SQR2, GENMASK(9, 5), 5 },
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{ STM32F4_ADC_SQR2, GENMASK(14, 10), 10 },
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{ STM32F4_ADC_SQR2, GENMASK(19, 15), 15 },
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{ STM32F4_ADC_SQR2, GENMASK(24, 20), 20 },
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{ STM32F4_ADC_SQR2, GENMASK(29, 25), 25 },
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{ STM32F4_ADC_SQR1, GENMASK(4, 0), 0 },
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{ STM32F4_ADC_SQR1, GENMASK(9, 5), 5 },
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{ STM32F4_ADC_SQR1, GENMASK(14, 10), 10 },
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{ STM32F4_ADC_SQR1, GENMASK(19, 15), 15 },
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};
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/* STM32F4 external trigger sources for all instances */
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static struct stm32_adc_trig_info stm32f4_adc_trigs[] = {
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{ TIM1_CH1, STM32_EXT0 },
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{ TIM1_CH2, STM32_EXT1 },
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{ TIM1_CH3, STM32_EXT2 },
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{ TIM2_CH2, STM32_EXT3 },
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{ TIM2_CH3, STM32_EXT4 },
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{ TIM2_CH4, STM32_EXT5 },
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{ TIM2_TRGO, STM32_EXT6 },
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{ TIM3_CH1, STM32_EXT7 },
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{ TIM3_TRGO, STM32_EXT8 },
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{ TIM4_CH4, STM32_EXT9 },
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{ TIM5_CH1, STM32_EXT10 },
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{ TIM5_CH2, STM32_EXT11 },
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{ TIM5_CH3, STM32_EXT12 },
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{ TIM8_CH1, STM32_EXT13 },
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{ TIM8_TRGO, STM32_EXT14 },
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{}, /* sentinel */
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};
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/*
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* stm32f4_smp_bits[] - describe sampling time register index & bit fields
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* Sorted so it can be indexed by channel number.
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*/
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static const struct stm32_adc_regs stm32f4_smp_bits[] = {
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/* STM32F4_ADC_SMPR2: smpr[] index, mask, shift for SMP0 to SMP9 */
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{ 1, GENMASK(2, 0), 0 },
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{ 1, GENMASK(5, 3), 3 },
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{ 1, GENMASK(8, 6), 6 },
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{ 1, GENMASK(11, 9), 9 },
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{ 1, GENMASK(14, 12), 12 },
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{ 1, GENMASK(17, 15), 15 },
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{ 1, GENMASK(20, 18), 18 },
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{ 1, GENMASK(23, 21), 21 },
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{ 1, GENMASK(26, 24), 24 },
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{ 1, GENMASK(29, 27), 27 },
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/* STM32F4_ADC_SMPR1, smpr[] index, mask, shift for SMP10 to SMP18 */
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{ 0, GENMASK(2, 0), 0 },
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{ 0, GENMASK(5, 3), 3 },
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{ 0, GENMASK(8, 6), 6 },
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{ 0, GENMASK(11, 9), 9 },
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{ 0, GENMASK(14, 12), 12 },
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{ 0, GENMASK(17, 15), 15 },
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{ 0, GENMASK(20, 18), 18 },
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{ 0, GENMASK(23, 21), 21 },
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{ 0, GENMASK(26, 24), 24 },
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};
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/* STM32F4 programmable sampling time (ADC clock cycles) */
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static const unsigned int stm32f4_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = {
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3, 15, 28, 56, 84, 112, 144, 480,
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};
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static const struct stm32_adc_regspec stm32f4_adc_regspec = {
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.dr = STM32F4_ADC_DR,
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.ier_eoc = { STM32F4_ADC_CR1, STM32F4_EOCIE },
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.ier_ovr = { STM32F4_ADC_CR1, STM32F4_OVRIE },
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.isr_eoc = { STM32F4_ADC_SR, STM32F4_EOC },
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.isr_ovr = { STM32F4_ADC_SR, STM32F4_OVR },
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.sqr = stm32f4_sq,
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.exten = { STM32F4_ADC_CR2, STM32F4_EXTEN_MASK, STM32F4_EXTEN_SHIFT },
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.extsel = { STM32F4_ADC_CR2, STM32F4_EXTSEL_MASK,
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STM32F4_EXTSEL_SHIFT },
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.res = { STM32F4_ADC_CR1, STM32F4_RES_MASK, STM32F4_RES_SHIFT },
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.smpr = { STM32F4_ADC_SMPR1, STM32F4_ADC_SMPR2 },
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.smp_bits = stm32f4_smp_bits,
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};
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static const struct stm32_adc_regs stm32h7_sq[STM32_ADC_MAX_SQ + 1] = {
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/* L: len bit field description to be kept as first element */
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{ STM32H7_ADC_SQR1, GENMASK(3, 0), 0 },
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/* SQ1..SQ16 registers & bit fields (reg, mask, shift) */
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{ STM32H7_ADC_SQR1, GENMASK(10, 6), 6 },
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{ STM32H7_ADC_SQR1, GENMASK(16, 12), 12 },
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{ STM32H7_ADC_SQR1, GENMASK(22, 18), 18 },
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{ STM32H7_ADC_SQR1, GENMASK(28, 24), 24 },
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{ STM32H7_ADC_SQR2, GENMASK(4, 0), 0 },
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{ STM32H7_ADC_SQR2, GENMASK(10, 6), 6 },
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{ STM32H7_ADC_SQR2, GENMASK(16, 12), 12 },
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{ STM32H7_ADC_SQR2, GENMASK(22, 18), 18 },
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{ STM32H7_ADC_SQR2, GENMASK(28, 24), 24 },
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{ STM32H7_ADC_SQR3, GENMASK(4, 0), 0 },
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{ STM32H7_ADC_SQR3, GENMASK(10, 6), 6 },
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{ STM32H7_ADC_SQR3, GENMASK(16, 12), 12 },
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{ STM32H7_ADC_SQR3, GENMASK(22, 18), 18 },
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{ STM32H7_ADC_SQR3, GENMASK(28, 24), 24 },
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{ STM32H7_ADC_SQR4, GENMASK(4, 0), 0 },
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{ STM32H7_ADC_SQR4, GENMASK(10, 6), 6 },
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};
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/* STM32H7 external trigger sources for all instances */
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static struct stm32_adc_trig_info stm32h7_adc_trigs[] = {
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{ TIM1_CH1, STM32_EXT0 },
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{ TIM1_CH2, STM32_EXT1 },
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{ TIM1_CH3, STM32_EXT2 },
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{ TIM2_CH2, STM32_EXT3 },
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{ TIM3_TRGO, STM32_EXT4 },
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{ TIM4_CH4, STM32_EXT5 },
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{ TIM8_TRGO, STM32_EXT7 },
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{ TIM8_TRGO2, STM32_EXT8 },
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{ TIM1_TRGO, STM32_EXT9 },
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{ TIM1_TRGO2, STM32_EXT10 },
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{ TIM2_TRGO, STM32_EXT11 },
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{ TIM4_TRGO, STM32_EXT12 },
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{ TIM6_TRGO, STM32_EXT13 },
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{ TIM15_TRGO, STM32_EXT14 },
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{ TIM3_CH4, STM32_EXT15 },
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{ LPTIM1_OUT, STM32_EXT18 },
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{ LPTIM2_OUT, STM32_EXT19 },
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{ LPTIM3_OUT, STM32_EXT20 },
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{},
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};
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/*
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* stm32h7_smp_bits - describe sampling time register index & bit fields
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* Sorted so it can be indexed by channel number.
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*/
|
|
static const struct stm32_adc_regs stm32h7_smp_bits[] = {
|
|
/* STM32H7_ADC_SMPR1, smpr[] index, mask, shift for SMP0 to SMP9 */
|
|
{ 0, GENMASK(2, 0), 0 },
|
|
{ 0, GENMASK(5, 3), 3 },
|
|
{ 0, GENMASK(8, 6), 6 },
|
|
{ 0, GENMASK(11, 9), 9 },
|
|
{ 0, GENMASK(14, 12), 12 },
|
|
{ 0, GENMASK(17, 15), 15 },
|
|
{ 0, GENMASK(20, 18), 18 },
|
|
{ 0, GENMASK(23, 21), 21 },
|
|
{ 0, GENMASK(26, 24), 24 },
|
|
{ 0, GENMASK(29, 27), 27 },
|
|
/* STM32H7_ADC_SMPR2, smpr[] index, mask, shift for SMP10 to SMP19 */
|
|
{ 1, GENMASK(2, 0), 0 },
|
|
{ 1, GENMASK(5, 3), 3 },
|
|
{ 1, GENMASK(8, 6), 6 },
|
|
{ 1, GENMASK(11, 9), 9 },
|
|
{ 1, GENMASK(14, 12), 12 },
|
|
{ 1, GENMASK(17, 15), 15 },
|
|
{ 1, GENMASK(20, 18), 18 },
|
|
{ 1, GENMASK(23, 21), 21 },
|
|
{ 1, GENMASK(26, 24), 24 },
|
|
{ 1, GENMASK(29, 27), 27 },
|
|
};
|
|
|
|
/* STM32H7 programmable sampling time (ADC clock cycles, rounded down) */
|
|
static const unsigned int stm32h7_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = {
|
|
1, 2, 8, 16, 32, 64, 387, 810,
|
|
};
|
|
|
|
static const struct stm32_adc_regspec stm32h7_adc_regspec = {
|
|
.dr = STM32H7_ADC_DR,
|
|
.ier_eoc = { STM32H7_ADC_IER, STM32H7_EOCIE },
|
|
.ier_ovr = { STM32H7_ADC_IER, STM32H7_OVRIE },
|
|
.isr_eoc = { STM32H7_ADC_ISR, STM32H7_EOC },
|
|
.isr_ovr = { STM32H7_ADC_ISR, STM32H7_OVR },
|
|
.sqr = stm32h7_sq,
|
|
.exten = { STM32H7_ADC_CFGR, STM32H7_EXTEN_MASK, STM32H7_EXTEN_SHIFT },
|
|
.extsel = { STM32H7_ADC_CFGR, STM32H7_EXTSEL_MASK,
|
|
STM32H7_EXTSEL_SHIFT },
|
|
.res = { STM32H7_ADC_CFGR, STM32H7_RES_MASK, STM32H7_RES_SHIFT },
|
|
.smpr = { STM32H7_ADC_SMPR1, STM32H7_ADC_SMPR2 },
|
|
.smp_bits = stm32h7_smp_bits,
|
|
};
|
|
|
|
/**
|
|
* STM32 ADC registers access routines
|
|
* @adc: stm32 adc instance
|
|
* @reg: reg offset in adc instance
|
|
*
|
|
* Note: All instances share same base, with 0x0, 0x100 or 0x200 offset resp.
|
|
* for adc1, adc2 and adc3.
|
|
*/
|
|
static u32 stm32_adc_readl(struct stm32_adc *adc, u32 reg)
|
|
{
|
|
return readl_relaxed(adc->common->base + adc->offset + reg);
|
|
}
|
|
|
|
#define stm32_adc_readl_addr(addr) stm32_adc_readl(adc, addr)
|
|
|
|
#define stm32_adc_readl_poll_timeout(reg, val, cond, sleep_us, timeout_us) \
|
|
readx_poll_timeout(stm32_adc_readl_addr, reg, val, \
|
|
cond, sleep_us, timeout_us)
|
|
|
|
static u16 stm32_adc_readw(struct stm32_adc *adc, u32 reg)
|
|
{
|
|
return readw_relaxed(adc->common->base + adc->offset + reg);
|
|
}
|
|
|
|
static void stm32_adc_writel(struct stm32_adc *adc, u32 reg, u32 val)
|
|
{
|
|
writel_relaxed(val, adc->common->base + adc->offset + reg);
|
|
}
|
|
|
|
static void stm32_adc_set_bits(struct stm32_adc *adc, u32 reg, u32 bits)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&adc->lock, flags);
|
|
stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) | bits);
|
|
spin_unlock_irqrestore(&adc->lock, flags);
|
|
}
|
|
|
|
static void stm32_adc_clr_bits(struct stm32_adc *adc, u32 reg, u32 bits)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&adc->lock, flags);
|
|
stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) & ~bits);
|
|
spin_unlock_irqrestore(&adc->lock, flags);
|
|
}
|
|
|
|
/**
|
|
* stm32_adc_conv_irq_enable() - Enable end of conversion interrupt
|
|
* @adc: stm32 adc instance
|
|
*/
|
|
static void stm32_adc_conv_irq_enable(struct stm32_adc *adc)
|
|
{
|
|
stm32_adc_set_bits(adc, adc->cfg->regs->ier_eoc.reg,
|
|
adc->cfg->regs->ier_eoc.mask);
|
|
};
|
|
|
|
/**
|
|
* stm32_adc_conv_irq_disable() - Disable end of conversion interrupt
|
|
* @adc: stm32 adc instance
|
|
*/
|
|
static void stm32_adc_conv_irq_disable(struct stm32_adc *adc)
|
|
{
|
|
stm32_adc_clr_bits(adc, adc->cfg->regs->ier_eoc.reg,
|
|
adc->cfg->regs->ier_eoc.mask);
|
|
}
|
|
|
|
static void stm32_adc_ovr_irq_enable(struct stm32_adc *adc)
|
|
{
|
|
stm32_adc_set_bits(adc, adc->cfg->regs->ier_ovr.reg,
|
|
adc->cfg->regs->ier_ovr.mask);
|
|
}
|
|
|
|
static void stm32_adc_ovr_irq_disable(struct stm32_adc *adc)
|
|
{
|
|
stm32_adc_clr_bits(adc, adc->cfg->regs->ier_ovr.reg,
|
|
adc->cfg->regs->ier_ovr.mask);
|
|
}
|
|
|
|
static void stm32_adc_set_res(struct stm32_adc *adc)
|
|
{
|
|
const struct stm32_adc_regs *res = &adc->cfg->regs->res;
|
|
u32 val;
|
|
|
|
val = stm32_adc_readl(adc, res->reg);
|
|
val = (val & ~res->mask) | (adc->res << res->shift);
|
|
stm32_adc_writel(adc, res->reg, val);
|
|
}
|
|
|
|
static int stm32_adc_hw_stop(struct device *dev)
|
|
{
|
|
struct iio_dev *indio_dev = dev_get_drvdata(dev);
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
|
|
if (adc->cfg->unprepare)
|
|
adc->cfg->unprepare(indio_dev);
|
|
|
|
clk_disable_unprepare(adc->clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_adc_hw_start(struct device *dev)
|
|
{
|
|
struct iio_dev *indio_dev = dev_get_drvdata(dev);
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int ret;
|
|
|
|
ret = clk_prepare_enable(adc->clk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
stm32_adc_set_res(adc);
|
|
|
|
if (adc->cfg->prepare) {
|
|
ret = adc->cfg->prepare(indio_dev);
|
|
if (ret)
|
|
goto err_clk_dis;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_clk_dis:
|
|
clk_disable_unprepare(adc->clk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* stm32f4_adc_start_conv() - Start conversions for regular channels.
|
|
* @indio_dev: IIO device instance
|
|
* @dma: use dma to transfer conversion result
|
|
*
|
|
* Start conversions for regular channels.
|
|
* Also take care of normal or DMA mode. Circular DMA may be used for regular
|
|
* conversions, in IIO buffer modes. Otherwise, use ADC interrupt with direct
|
|
* DR read instead (e.g. read_raw, or triggered buffer mode without DMA).
|
|
*/
|
|
static void stm32f4_adc_start_conv(struct iio_dev *indio_dev, bool dma)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
|
|
stm32_adc_set_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN);
|
|
|
|
if (dma)
|
|
stm32_adc_set_bits(adc, STM32F4_ADC_CR2,
|
|
STM32F4_DMA | STM32F4_DDS);
|
|
|
|
stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_EOCS | STM32F4_ADON);
|
|
|
|
/* Wait for Power-up time (tSTAB from datasheet) */
|
|
usleep_range(2, 3);
|
|
|
|
/* Software start ? (e.g. trigger detection disabled ?) */
|
|
if (!(stm32_adc_readl(adc, STM32F4_ADC_CR2) & STM32F4_EXTEN_MASK))
|
|
stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_SWSTART);
|
|
}
|
|
|
|
static void stm32f4_adc_stop_conv(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
|
|
stm32_adc_clr_bits(adc, STM32F4_ADC_CR2, STM32F4_EXTEN_MASK);
|
|
stm32_adc_clr_bits(adc, STM32F4_ADC_SR, STM32F4_STRT);
|
|
|
|
stm32_adc_clr_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN);
|
|
stm32_adc_clr_bits(adc, STM32F4_ADC_CR2,
|
|
STM32F4_ADON | STM32F4_DMA | STM32F4_DDS);
|
|
}
|
|
|
|
static void stm32f4_adc_irq_clear(struct iio_dev *indio_dev, u32 msk)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
|
|
stm32_adc_clr_bits(adc, adc->cfg->regs->isr_eoc.reg, msk);
|
|
}
|
|
|
|
static void stm32h7_adc_start_conv(struct iio_dev *indio_dev, bool dma)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
enum stm32h7_adc_dmngt dmngt;
|
|
unsigned long flags;
|
|
u32 val;
|
|
|
|
if (dma)
|
|
dmngt = STM32H7_DMNGT_DMA_CIRC;
|
|
else
|
|
dmngt = STM32H7_DMNGT_DR_ONLY;
|
|
|
|
spin_lock_irqsave(&adc->lock, flags);
|
|
val = stm32_adc_readl(adc, STM32H7_ADC_CFGR);
|
|
val = (val & ~STM32H7_DMNGT_MASK) | (dmngt << STM32H7_DMNGT_SHIFT);
|
|
stm32_adc_writel(adc, STM32H7_ADC_CFGR, val);
|
|
spin_unlock_irqrestore(&adc->lock, flags);
|
|
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTART);
|
|
}
|
|
|
|
static void stm32h7_adc_stop_conv(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int ret;
|
|
u32 val;
|
|
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTP);
|
|
|
|
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
|
|
!(val & (STM32H7_ADSTART)),
|
|
100, STM32_ADC_TIMEOUT_US);
|
|
if (ret)
|
|
dev_warn(&indio_dev->dev, "stop failed\n");
|
|
|
|
stm32_adc_clr_bits(adc, STM32H7_ADC_CFGR, STM32H7_DMNGT_MASK);
|
|
}
|
|
|
|
static void stm32h7_adc_irq_clear(struct iio_dev *indio_dev, u32 msk)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
/* On STM32H7 IRQs are cleared by writing 1 into ISR register */
|
|
stm32_adc_set_bits(adc, adc->cfg->regs->isr_eoc.reg, msk);
|
|
}
|
|
|
|
static int stm32h7_adc_exit_pwr_down(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int ret;
|
|
u32 val;
|
|
|
|
/* Exit deep power down, then enable ADC voltage regulator */
|
|
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADVREGEN);
|
|
|
|
if (adc->common->rate > STM32H7_BOOST_CLKRATE)
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST);
|
|
|
|
/* Wait for startup time */
|
|
if (!adc->cfg->has_vregready) {
|
|
usleep_range(10, 20);
|
|
return 0;
|
|
}
|
|
|
|
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val,
|
|
val & STM32MP1_VREGREADY, 100,
|
|
STM32_ADC_TIMEOUT_US);
|
|
if (ret) {
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
|
|
dev_err(&indio_dev->dev, "Failed to exit power down\n");
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void stm32h7_adc_enter_pwr_down(struct stm32_adc *adc)
|
|
{
|
|
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST);
|
|
|
|
/* Setting DEEPPWD disables ADC vreg and clears ADVREGEN */
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
|
|
}
|
|
|
|
static int stm32h7_adc_enable(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int ret;
|
|
u32 val;
|
|
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADEN);
|
|
|
|
/* Poll for ADRDY to be set (after adc startup time) */
|
|
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val,
|
|
val & STM32H7_ADRDY,
|
|
100, STM32_ADC_TIMEOUT_US);
|
|
if (ret) {
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS);
|
|
dev_err(&indio_dev->dev, "Failed to enable ADC\n");
|
|
} else {
|
|
/* Clear ADRDY by writing one */
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_ISR, STM32H7_ADRDY);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void stm32h7_adc_disable(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int ret;
|
|
u32 val;
|
|
|
|
/* Disable ADC and wait until it's effectively disabled */
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS);
|
|
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
|
|
!(val & STM32H7_ADEN), 100,
|
|
STM32_ADC_TIMEOUT_US);
|
|
if (ret)
|
|
dev_warn(&indio_dev->dev, "Failed to disable\n");
|
|
}
|
|
|
|
/**
|
|
* stm32h7_adc_read_selfcalib() - read calibration shadow regs, save result
|
|
* @indio_dev: IIO device instance
|
|
* Note: Must be called once ADC is enabled, so LINCALRDYW[1..6] are writable
|
|
*/
|
|
static int stm32h7_adc_read_selfcalib(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int i, ret;
|
|
u32 lincalrdyw_mask, val;
|
|
|
|
/* Read linearity calibration */
|
|
lincalrdyw_mask = STM32H7_LINCALRDYW6;
|
|
for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) {
|
|
/* Clear STM32H7_LINCALRDYW[6..1]: transfer calib to CALFACT2 */
|
|
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
|
|
|
|
/* Poll: wait calib data to be ready in CALFACT2 register */
|
|
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
|
|
!(val & lincalrdyw_mask),
|
|
100, STM32_ADC_TIMEOUT_US);
|
|
if (ret) {
|
|
dev_err(&indio_dev->dev, "Failed to read calfact\n");
|
|
return ret;
|
|
}
|
|
|
|
val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2);
|
|
adc->cal.lincalfact[i] = (val & STM32H7_LINCALFACT_MASK);
|
|
adc->cal.lincalfact[i] >>= STM32H7_LINCALFACT_SHIFT;
|
|
|
|
lincalrdyw_mask >>= 1;
|
|
}
|
|
|
|
/* Read offset calibration */
|
|
val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT);
|
|
adc->cal.calfact_s = (val & STM32H7_CALFACT_S_MASK);
|
|
adc->cal.calfact_s >>= STM32H7_CALFACT_S_SHIFT;
|
|
adc->cal.calfact_d = (val & STM32H7_CALFACT_D_MASK);
|
|
adc->cal.calfact_d >>= STM32H7_CALFACT_D_SHIFT;
|
|
adc->cal.calibrated = true;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* stm32h7_adc_restore_selfcalib() - Restore saved self-calibration result
|
|
* @indio_dev: IIO device instance
|
|
* Note: ADC must be enabled, with no on-going conversions.
|
|
*/
|
|
static int stm32h7_adc_restore_selfcalib(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int i, ret;
|
|
u32 lincalrdyw_mask, val;
|
|
|
|
val = (adc->cal.calfact_s << STM32H7_CALFACT_S_SHIFT) |
|
|
(adc->cal.calfact_d << STM32H7_CALFACT_D_SHIFT);
|
|
stm32_adc_writel(adc, STM32H7_ADC_CALFACT, val);
|
|
|
|
lincalrdyw_mask = STM32H7_LINCALRDYW6;
|
|
for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) {
|
|
/*
|
|
* Write saved calibration data to shadow registers:
|
|
* Write CALFACT2, and set LINCALRDYW[6..1] bit to trigger
|
|
* data write. Then poll to wait for complete transfer.
|
|
*/
|
|
val = adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT;
|
|
stm32_adc_writel(adc, STM32H7_ADC_CALFACT2, val);
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
|
|
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
|
|
val & lincalrdyw_mask,
|
|
100, STM32_ADC_TIMEOUT_US);
|
|
if (ret) {
|
|
dev_err(&indio_dev->dev, "Failed to write calfact\n");
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Read back calibration data, has two effects:
|
|
* - It ensures bits LINCALRDYW[6..1] are kept cleared
|
|
* for next time calibration needs to be restored.
|
|
* - BTW, bit clear triggers a read, then check data has been
|
|
* correctly written.
|
|
*/
|
|
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
|
|
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
|
|
!(val & lincalrdyw_mask),
|
|
100, STM32_ADC_TIMEOUT_US);
|
|
if (ret) {
|
|
dev_err(&indio_dev->dev, "Failed to read calfact\n");
|
|
return ret;
|
|
}
|
|
val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2);
|
|
if (val != adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT) {
|
|
dev_err(&indio_dev->dev, "calfact not consistent\n");
|
|
return -EIO;
|
|
}
|
|
|
|
lincalrdyw_mask >>= 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Fixed timeout value for ADC calibration.
|
|
* worst cases:
|
|
* - low clock frequency
|
|
* - maximum prescalers
|
|
* Calibration requires:
|
|
* - 131,072 ADC clock cycle for the linear calibration
|
|
* - 20 ADC clock cycle for the offset calibration
|
|
*
|
|
* Set to 100ms for now
|
|
*/
|
|
#define STM32H7_ADC_CALIB_TIMEOUT_US 100000
|
|
|
|
/**
|
|
* stm32h7_adc_selfcalib() - Procedure to calibrate ADC
|
|
* @indio_dev: IIO device instance
|
|
* Note: Must be called once ADC is out of power down.
|
|
*/
|
|
static int stm32h7_adc_selfcalib(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int ret;
|
|
u32 val;
|
|
|
|
if (adc->cal.calibrated)
|
|
return true;
|
|
|
|
/*
|
|
* Select calibration mode:
|
|
* - Offset calibration for single ended inputs
|
|
* - No linearity calibration (do it later, before reading it)
|
|
*/
|
|
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALDIF);
|
|
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALLIN);
|
|
|
|
/* Start calibration, then wait for completion */
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL);
|
|
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
|
|
!(val & STM32H7_ADCAL), 100,
|
|
STM32H7_ADC_CALIB_TIMEOUT_US);
|
|
if (ret) {
|
|
dev_err(&indio_dev->dev, "calibration failed\n");
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Select calibration mode, then start calibration:
|
|
* - Offset calibration for differential input
|
|
* - Linearity calibration (needs to be done only once for single/diff)
|
|
* will run simultaneously with offset calibration.
|
|
*/
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR,
|
|
STM32H7_ADCALDIF | STM32H7_ADCALLIN);
|
|
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL);
|
|
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
|
|
!(val & STM32H7_ADCAL), 100,
|
|
STM32H7_ADC_CALIB_TIMEOUT_US);
|
|
if (ret) {
|
|
dev_err(&indio_dev->dev, "calibration failed\n");
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
stm32_adc_clr_bits(adc, STM32H7_ADC_CR,
|
|
STM32H7_ADCALDIF | STM32H7_ADCALLIN);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* stm32h7_adc_prepare() - Leave power down mode to enable ADC.
|
|
* @indio_dev: IIO device instance
|
|
* Leave power down mode.
|
|
* Configure channels as single ended or differential before enabling ADC.
|
|
* Enable ADC.
|
|
* Restore calibration data.
|
|
* Pre-select channels that may be used in PCSEL (required by input MUX / IO):
|
|
* - Only one input is selected for single ended (e.g. 'vinp')
|
|
* - Two inputs are selected for differential channels (e.g. 'vinp' & 'vinn')
|
|
*/
|
|
static int stm32h7_adc_prepare(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int calib, ret;
|
|
|
|
ret = stm32h7_adc_exit_pwr_down(indio_dev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = stm32h7_adc_selfcalib(indio_dev);
|
|
if (ret < 0)
|
|
goto pwr_dwn;
|
|
calib = ret;
|
|
|
|
stm32_adc_writel(adc, STM32H7_ADC_DIFSEL, adc->difsel);
|
|
|
|
ret = stm32h7_adc_enable(indio_dev);
|
|
if (ret)
|
|
goto pwr_dwn;
|
|
|
|
/* Either restore or read calibration result for future reference */
|
|
if (calib)
|
|
ret = stm32h7_adc_restore_selfcalib(indio_dev);
|
|
else
|
|
ret = stm32h7_adc_read_selfcalib(indio_dev);
|
|
if (ret)
|
|
goto disable;
|
|
|
|
stm32_adc_writel(adc, STM32H7_ADC_PCSEL, adc->pcsel);
|
|
|
|
return 0;
|
|
|
|
disable:
|
|
stm32h7_adc_disable(indio_dev);
|
|
pwr_dwn:
|
|
stm32h7_adc_enter_pwr_down(adc);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void stm32h7_adc_unprepare(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
|
|
stm32h7_adc_disable(indio_dev);
|
|
stm32h7_adc_enter_pwr_down(adc);
|
|
}
|
|
|
|
/**
|
|
* stm32_adc_conf_scan_seq() - Build regular channels scan sequence
|
|
* @indio_dev: IIO device
|
|
* @scan_mask: channels to be converted
|
|
*
|
|
* Conversion sequence :
|
|
* Apply sampling time settings for all channels.
|
|
* Configure ADC scan sequence based on selected channels in scan_mask.
|
|
* Add channels to SQR registers, from scan_mask LSB to MSB, then
|
|
* program sequence len.
|
|
*/
|
|
static int stm32_adc_conf_scan_seq(struct iio_dev *indio_dev,
|
|
const unsigned long *scan_mask)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
const struct stm32_adc_regs *sqr = adc->cfg->regs->sqr;
|
|
const struct iio_chan_spec *chan;
|
|
u32 val, bit;
|
|
int i = 0;
|
|
|
|
/* Apply sampling time settings */
|
|
stm32_adc_writel(adc, adc->cfg->regs->smpr[0], adc->smpr_val[0]);
|
|
stm32_adc_writel(adc, adc->cfg->regs->smpr[1], adc->smpr_val[1]);
|
|
|
|
for_each_set_bit(bit, scan_mask, indio_dev->masklength) {
|
|
chan = indio_dev->channels + bit;
|
|
/*
|
|
* Assign one channel per SQ entry in regular
|
|
* sequence, starting with SQ1.
|
|
*/
|
|
i++;
|
|
if (i > STM32_ADC_MAX_SQ)
|
|
return -EINVAL;
|
|
|
|
dev_dbg(&indio_dev->dev, "%s chan %d to SQ%d\n",
|
|
__func__, chan->channel, i);
|
|
|
|
val = stm32_adc_readl(adc, sqr[i].reg);
|
|
val &= ~sqr[i].mask;
|
|
val |= chan->channel << sqr[i].shift;
|
|
stm32_adc_writel(adc, sqr[i].reg, val);
|
|
}
|
|
|
|
if (!i)
|
|
return -EINVAL;
|
|
|
|
/* Sequence len */
|
|
val = stm32_adc_readl(adc, sqr[0].reg);
|
|
val &= ~sqr[0].mask;
|
|
val |= ((i - 1) << sqr[0].shift);
|
|
stm32_adc_writel(adc, sqr[0].reg, val);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* stm32_adc_get_trig_extsel() - Get external trigger selection
|
|
* @indio_dev: IIO device structure
|
|
* @trig: trigger
|
|
*
|
|
* Returns trigger extsel value, if trig matches, -EINVAL otherwise.
|
|
*/
|
|
static int stm32_adc_get_trig_extsel(struct iio_dev *indio_dev,
|
|
struct iio_trigger *trig)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int i;
|
|
|
|
/* lookup triggers registered by stm32 timer trigger driver */
|
|
for (i = 0; adc->cfg->trigs[i].name; i++) {
|
|
/**
|
|
* Checking both stm32 timer trigger type and trig name
|
|
* should be safe against arbitrary trigger names.
|
|
*/
|
|
if ((is_stm32_timer_trigger(trig) ||
|
|
is_stm32_lptim_trigger(trig)) &&
|
|
!strcmp(adc->cfg->trigs[i].name, trig->name)) {
|
|
return adc->cfg->trigs[i].extsel;
|
|
}
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
/**
|
|
* stm32_adc_set_trig() - Set a regular trigger
|
|
* @indio_dev: IIO device
|
|
* @trig: IIO trigger
|
|
*
|
|
* Set trigger source/polarity (e.g. SW, or HW with polarity) :
|
|
* - if HW trigger disabled (e.g. trig == NULL, conversion launched by sw)
|
|
* - if HW trigger enabled, set source & polarity
|
|
*/
|
|
static int stm32_adc_set_trig(struct iio_dev *indio_dev,
|
|
struct iio_trigger *trig)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
u32 val, extsel = 0, exten = STM32_EXTEN_SWTRIG;
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
if (trig) {
|
|
ret = stm32_adc_get_trig_extsel(indio_dev, trig);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
/* set trigger source and polarity (default to rising edge) */
|
|
extsel = ret;
|
|
exten = adc->trigger_polarity + STM32_EXTEN_HWTRIG_RISING_EDGE;
|
|
}
|
|
|
|
spin_lock_irqsave(&adc->lock, flags);
|
|
val = stm32_adc_readl(adc, adc->cfg->regs->exten.reg);
|
|
val &= ~(adc->cfg->regs->exten.mask | adc->cfg->regs->extsel.mask);
|
|
val |= exten << adc->cfg->regs->exten.shift;
|
|
val |= extsel << adc->cfg->regs->extsel.shift;
|
|
stm32_adc_writel(adc, adc->cfg->regs->exten.reg, val);
|
|
spin_unlock_irqrestore(&adc->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_adc_set_trig_pol(struct iio_dev *indio_dev,
|
|
const struct iio_chan_spec *chan,
|
|
unsigned int type)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
|
|
adc->trigger_polarity = type;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_adc_get_trig_pol(struct iio_dev *indio_dev,
|
|
const struct iio_chan_spec *chan)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
|
|
return adc->trigger_polarity;
|
|
}
|
|
|
|
static const char * const stm32_trig_pol_items[] = {
|
|
"rising-edge", "falling-edge", "both-edges",
|
|
};
|
|
|
|
static const struct iio_enum stm32_adc_trig_pol = {
|
|
.items = stm32_trig_pol_items,
|
|
.num_items = ARRAY_SIZE(stm32_trig_pol_items),
|
|
.get = stm32_adc_get_trig_pol,
|
|
.set = stm32_adc_set_trig_pol,
|
|
};
|
|
|
|
/**
|
|
* stm32_adc_single_conv() - Performs a single conversion
|
|
* @indio_dev: IIO device
|
|
* @chan: IIO channel
|
|
* @res: conversion result
|
|
*
|
|
* The function performs a single conversion on a given channel:
|
|
* - Apply sampling time settings
|
|
* - Program sequencer with one channel (e.g. in SQ1 with len = 1)
|
|
* - Use SW trigger
|
|
* - Start conversion, then wait for interrupt completion.
|
|
*/
|
|
static int stm32_adc_single_conv(struct iio_dev *indio_dev,
|
|
const struct iio_chan_spec *chan,
|
|
int *res)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
struct device *dev = indio_dev->dev.parent;
|
|
const struct stm32_adc_regspec *regs = adc->cfg->regs;
|
|
long timeout;
|
|
u32 val;
|
|
int ret;
|
|
|
|
reinit_completion(&adc->completion);
|
|
|
|
adc->bufi = 0;
|
|
|
|
ret = pm_runtime_get_sync(dev);
|
|
if (ret < 0) {
|
|
pm_runtime_put_noidle(dev);
|
|
return ret;
|
|
}
|
|
|
|
/* Apply sampling time settings */
|
|
stm32_adc_writel(adc, regs->smpr[0], adc->smpr_val[0]);
|
|
stm32_adc_writel(adc, regs->smpr[1], adc->smpr_val[1]);
|
|
|
|
/* Program chan number in regular sequence (SQ1) */
|
|
val = stm32_adc_readl(adc, regs->sqr[1].reg);
|
|
val &= ~regs->sqr[1].mask;
|
|
val |= chan->channel << regs->sqr[1].shift;
|
|
stm32_adc_writel(adc, regs->sqr[1].reg, val);
|
|
|
|
/* Set regular sequence len (0 for 1 conversion) */
|
|
stm32_adc_clr_bits(adc, regs->sqr[0].reg, regs->sqr[0].mask);
|
|
|
|
/* Trigger detection disabled (conversion can be launched in SW) */
|
|
stm32_adc_clr_bits(adc, regs->exten.reg, regs->exten.mask);
|
|
|
|
stm32_adc_conv_irq_enable(adc);
|
|
|
|
adc->cfg->start_conv(indio_dev, false);
|
|
|
|
timeout = wait_for_completion_interruptible_timeout(
|
|
&adc->completion, STM32_ADC_TIMEOUT);
|
|
if (timeout == 0) {
|
|
ret = -ETIMEDOUT;
|
|
} else if (timeout < 0) {
|
|
ret = timeout;
|
|
} else {
|
|
*res = adc->buffer[0];
|
|
ret = IIO_VAL_INT;
|
|
}
|
|
|
|
adc->cfg->stop_conv(indio_dev);
|
|
|
|
stm32_adc_conv_irq_disable(adc);
|
|
|
|
pm_runtime_mark_last_busy(dev);
|
|
pm_runtime_put_autosuspend(dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_adc_read_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan,
|
|
int *val, int *val2, long mask)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int ret;
|
|
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_RAW:
|
|
ret = iio_device_claim_direct_mode(indio_dev);
|
|
if (ret)
|
|
return ret;
|
|
if (chan->type == IIO_VOLTAGE)
|
|
ret = stm32_adc_single_conv(indio_dev, chan, val);
|
|
else
|
|
ret = -EINVAL;
|
|
iio_device_release_direct_mode(indio_dev);
|
|
return ret;
|
|
|
|
case IIO_CHAN_INFO_SCALE:
|
|
if (chan->differential) {
|
|
*val = adc->common->vref_mv * 2;
|
|
*val2 = chan->scan_type.realbits;
|
|
} else {
|
|
*val = adc->common->vref_mv;
|
|
*val2 = chan->scan_type.realbits;
|
|
}
|
|
return IIO_VAL_FRACTIONAL_LOG2;
|
|
|
|
case IIO_CHAN_INFO_OFFSET:
|
|
if (chan->differential)
|
|
/* ADC_full_scale / 2 */
|
|
*val = -((1 << chan->scan_type.realbits) / 2);
|
|
else
|
|
*val = 0;
|
|
return IIO_VAL_INT;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
static void stm32_adc_irq_clear(struct iio_dev *indio_dev, u32 msk)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
|
|
adc->cfg->irq_clear(indio_dev, msk);
|
|
}
|
|
|
|
static irqreturn_t stm32_adc_threaded_isr(int irq, void *data)
|
|
{
|
|
struct iio_dev *indio_dev = data;
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
const struct stm32_adc_regspec *regs = adc->cfg->regs;
|
|
u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg);
|
|
u32 mask = stm32_adc_readl(adc, regs->ier_eoc.reg);
|
|
|
|
/* Check ovr status right now, as ovr mask should be already disabled */
|
|
if (status & regs->isr_ovr.mask) {
|
|
/*
|
|
* Clear ovr bit to avoid subsequent calls to IRQ handler.
|
|
* This requires to stop ADC first. OVR bit state in ISR,
|
|
* is propaged to CSR register by hardware.
|
|
*/
|
|
adc->cfg->stop_conv(indio_dev);
|
|
stm32_adc_irq_clear(indio_dev, regs->isr_ovr.mask);
|
|
dev_err(&indio_dev->dev, "Overrun, stopping: restart needed\n");
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
if (!(status & mask))
|
|
dev_err_ratelimited(&indio_dev->dev,
|
|
"Unexpected IRQ: IER=0x%08x, ISR=0x%08x\n",
|
|
mask, status);
|
|
|
|
return IRQ_NONE;
|
|
}
|
|
|
|
static irqreturn_t stm32_adc_isr(int irq, void *data)
|
|
{
|
|
struct iio_dev *indio_dev = data;
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
const struct stm32_adc_regspec *regs = adc->cfg->regs;
|
|
u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg);
|
|
u32 mask = stm32_adc_readl(adc, regs->ier_eoc.reg);
|
|
|
|
if (!(status & mask))
|
|
return IRQ_WAKE_THREAD;
|
|
|
|
if (status & regs->isr_ovr.mask) {
|
|
/*
|
|
* Overrun occurred on regular conversions: data for wrong
|
|
* channel may be read. Unconditionally disable interrupts
|
|
* to stop processing data and print error message.
|
|
* Restarting the capture can be done by disabling, then
|
|
* re-enabling it (e.g. write 0, then 1 to buffer/enable).
|
|
*/
|
|
stm32_adc_ovr_irq_disable(adc);
|
|
stm32_adc_conv_irq_disable(adc);
|
|
return IRQ_WAKE_THREAD;
|
|
}
|
|
|
|
if (status & regs->isr_eoc.mask) {
|
|
/* Reading DR also clears EOC status flag */
|
|
adc->buffer[adc->bufi] = stm32_adc_readw(adc, regs->dr);
|
|
if (iio_buffer_enabled(indio_dev)) {
|
|
adc->bufi++;
|
|
if (adc->bufi >= adc->num_conv) {
|
|
stm32_adc_conv_irq_disable(adc);
|
|
iio_trigger_poll(indio_dev->trig);
|
|
}
|
|
} else {
|
|
complete(&adc->completion);
|
|
}
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
return IRQ_NONE;
|
|
}
|
|
|
|
/**
|
|
* stm32_adc_validate_trigger() - validate trigger for stm32 adc
|
|
* @indio_dev: IIO device
|
|
* @trig: new trigger
|
|
*
|
|
* Returns: 0 if trig matches one of the triggers registered by stm32 adc
|
|
* driver, -EINVAL otherwise.
|
|
*/
|
|
static int stm32_adc_validate_trigger(struct iio_dev *indio_dev,
|
|
struct iio_trigger *trig)
|
|
{
|
|
return stm32_adc_get_trig_extsel(indio_dev, trig) < 0 ? -EINVAL : 0;
|
|
}
|
|
|
|
static int stm32_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
unsigned int watermark = STM32_DMA_BUFFER_SIZE / 2;
|
|
unsigned int rx_buf_sz = STM32_DMA_BUFFER_SIZE;
|
|
|
|
/*
|
|
* dma cyclic transfers are used, buffer is split into two periods.
|
|
* There should be :
|
|
* - always one buffer (period) dma is working on
|
|
* - one buffer (period) driver can push data.
|
|
*/
|
|
watermark = min(watermark, val * (unsigned)(sizeof(u16)));
|
|
adc->rx_buf_sz = min(rx_buf_sz, watermark * 2 * adc->num_conv);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_adc_update_scan_mode(struct iio_dev *indio_dev,
|
|
const unsigned long *scan_mask)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
struct device *dev = indio_dev->dev.parent;
|
|
int ret;
|
|
|
|
ret = pm_runtime_get_sync(dev);
|
|
if (ret < 0) {
|
|
pm_runtime_put_noidle(dev);
|
|
return ret;
|
|
}
|
|
|
|
adc->num_conv = bitmap_weight(scan_mask, indio_dev->masklength);
|
|
|
|
ret = stm32_adc_conf_scan_seq(indio_dev, scan_mask);
|
|
pm_runtime_mark_last_busy(dev);
|
|
pm_runtime_put_autosuspend(dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_adc_of_xlate(struct iio_dev *indio_dev,
|
|
const struct of_phandle_args *iiospec)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < indio_dev->num_channels; i++)
|
|
if (indio_dev->channels[i].channel == iiospec->args[0])
|
|
return i;
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
/**
|
|
* stm32_adc_debugfs_reg_access - read or write register value
|
|
* @indio_dev: IIO device structure
|
|
* @reg: register offset
|
|
* @writeval: value to write
|
|
* @readval: value to read
|
|
*
|
|
* To read a value from an ADC register:
|
|
* echo [ADC reg offset] > direct_reg_access
|
|
* cat direct_reg_access
|
|
*
|
|
* To write a value in a ADC register:
|
|
* echo [ADC_reg_offset] [value] > direct_reg_access
|
|
*/
|
|
static int stm32_adc_debugfs_reg_access(struct iio_dev *indio_dev,
|
|
unsigned reg, unsigned writeval,
|
|
unsigned *readval)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
struct device *dev = indio_dev->dev.parent;
|
|
int ret;
|
|
|
|
ret = pm_runtime_get_sync(dev);
|
|
if (ret < 0) {
|
|
pm_runtime_put_noidle(dev);
|
|
return ret;
|
|
}
|
|
|
|
if (!readval)
|
|
stm32_adc_writel(adc, reg, writeval);
|
|
else
|
|
*readval = stm32_adc_readl(adc, reg);
|
|
|
|
pm_runtime_mark_last_busy(dev);
|
|
pm_runtime_put_autosuspend(dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct iio_info stm32_adc_iio_info = {
|
|
.read_raw = stm32_adc_read_raw,
|
|
.validate_trigger = stm32_adc_validate_trigger,
|
|
.hwfifo_set_watermark = stm32_adc_set_watermark,
|
|
.update_scan_mode = stm32_adc_update_scan_mode,
|
|
.debugfs_reg_access = stm32_adc_debugfs_reg_access,
|
|
.of_xlate = stm32_adc_of_xlate,
|
|
};
|
|
|
|
static unsigned int stm32_adc_dma_residue(struct stm32_adc *adc)
|
|
{
|
|
struct dma_tx_state state;
|
|
enum dma_status status;
|
|
|
|
status = dmaengine_tx_status(adc->dma_chan,
|
|
adc->dma_chan->cookie,
|
|
&state);
|
|
if (status == DMA_IN_PROGRESS) {
|
|
/* Residue is size in bytes from end of buffer */
|
|
unsigned int i = adc->rx_buf_sz - state.residue;
|
|
unsigned int size;
|
|
|
|
/* Return available bytes */
|
|
if (i >= adc->bufi)
|
|
size = i - adc->bufi;
|
|
else
|
|
size = adc->rx_buf_sz + i - adc->bufi;
|
|
|
|
return size;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void stm32_adc_dma_buffer_done(void *data)
|
|
{
|
|
struct iio_dev *indio_dev = data;
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
int residue = stm32_adc_dma_residue(adc);
|
|
|
|
/*
|
|
* In DMA mode the trigger services of IIO are not used
|
|
* (e.g. no call to iio_trigger_poll).
|
|
* Calling irq handler associated to the hardware trigger is not
|
|
* relevant as the conversions have already been done. Data
|
|
* transfers are performed directly in DMA callback instead.
|
|
* This implementation avoids to call trigger irq handler that
|
|
* may sleep, in an atomic context (DMA irq handler context).
|
|
*/
|
|
dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);
|
|
|
|
while (residue >= indio_dev->scan_bytes) {
|
|
u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi];
|
|
|
|
iio_push_to_buffers(indio_dev, buffer);
|
|
|
|
residue -= indio_dev->scan_bytes;
|
|
adc->bufi += indio_dev->scan_bytes;
|
|
if (adc->bufi >= adc->rx_buf_sz)
|
|
adc->bufi = 0;
|
|
}
|
|
}
|
|
|
|
static int stm32_adc_dma_start(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
struct dma_async_tx_descriptor *desc;
|
|
dma_cookie_t cookie;
|
|
int ret;
|
|
|
|
if (!adc->dma_chan)
|
|
return 0;
|
|
|
|
dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
|
|
adc->rx_buf_sz, adc->rx_buf_sz / 2);
|
|
|
|
/* Prepare a DMA cyclic transaction */
|
|
desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
|
|
adc->rx_dma_buf,
|
|
adc->rx_buf_sz, adc->rx_buf_sz / 2,
|
|
DMA_DEV_TO_MEM,
|
|
DMA_PREP_INTERRUPT);
|
|
if (!desc)
|
|
return -EBUSY;
|
|
|
|
desc->callback = stm32_adc_dma_buffer_done;
|
|
desc->callback_param = indio_dev;
|
|
|
|
cookie = dmaengine_submit(desc);
|
|
ret = dma_submit_error(cookie);
|
|
if (ret) {
|
|
dmaengine_terminate_sync(adc->dma_chan);
|
|
return ret;
|
|
}
|
|
|
|
/* Issue pending DMA requests */
|
|
dma_async_issue_pending(adc->dma_chan);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_adc_buffer_postenable(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
struct device *dev = indio_dev->dev.parent;
|
|
int ret;
|
|
|
|
ret = pm_runtime_get_sync(dev);
|
|
if (ret < 0) {
|
|
pm_runtime_put_noidle(dev);
|
|
return ret;
|
|
}
|
|
|
|
ret = stm32_adc_set_trig(indio_dev, indio_dev->trig);
|
|
if (ret) {
|
|
dev_err(&indio_dev->dev, "Can't set trigger\n");
|
|
goto err_pm_put;
|
|
}
|
|
|
|
ret = stm32_adc_dma_start(indio_dev);
|
|
if (ret) {
|
|
dev_err(&indio_dev->dev, "Can't start dma\n");
|
|
goto err_clr_trig;
|
|
}
|
|
|
|
/* Reset adc buffer index */
|
|
adc->bufi = 0;
|
|
|
|
stm32_adc_ovr_irq_enable(adc);
|
|
|
|
if (!adc->dma_chan)
|
|
stm32_adc_conv_irq_enable(adc);
|
|
|
|
adc->cfg->start_conv(indio_dev, !!adc->dma_chan);
|
|
|
|
return 0;
|
|
|
|
err_clr_trig:
|
|
stm32_adc_set_trig(indio_dev, NULL);
|
|
err_pm_put:
|
|
pm_runtime_mark_last_busy(dev);
|
|
pm_runtime_put_autosuspend(dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_adc_buffer_predisable(struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
struct device *dev = indio_dev->dev.parent;
|
|
|
|
adc->cfg->stop_conv(indio_dev);
|
|
if (!adc->dma_chan)
|
|
stm32_adc_conv_irq_disable(adc);
|
|
|
|
stm32_adc_ovr_irq_disable(adc);
|
|
|
|
if (adc->dma_chan)
|
|
dmaengine_terminate_sync(adc->dma_chan);
|
|
|
|
if (stm32_adc_set_trig(indio_dev, NULL))
|
|
dev_err(&indio_dev->dev, "Can't clear trigger\n");
|
|
|
|
pm_runtime_mark_last_busy(dev);
|
|
pm_runtime_put_autosuspend(dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct iio_buffer_setup_ops stm32_adc_buffer_setup_ops = {
|
|
.postenable = &stm32_adc_buffer_postenable,
|
|
.predisable = &stm32_adc_buffer_predisable,
|
|
};
|
|
|
|
static irqreturn_t stm32_adc_trigger_handler(int irq, void *p)
|
|
{
|
|
struct iio_poll_func *pf = p;
|
|
struct iio_dev *indio_dev = pf->indio_dev;
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
|
|
dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);
|
|
|
|
/* reset buffer index */
|
|
adc->bufi = 0;
|
|
iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,
|
|
pf->timestamp);
|
|
iio_trigger_notify_done(indio_dev->trig);
|
|
|
|
/* re-enable eoc irq */
|
|
stm32_adc_conv_irq_enable(adc);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = {
|
|
IIO_ENUM("trigger_polarity", IIO_SHARED_BY_ALL, &stm32_adc_trig_pol),
|
|
{
|
|
.name = "trigger_polarity_available",
|
|
.shared = IIO_SHARED_BY_ALL,
|
|
.read = iio_enum_available_read,
|
|
.private = (uintptr_t)&stm32_adc_trig_pol,
|
|
},
|
|
{},
|
|
};
|
|
|
|
static int stm32_adc_of_get_resolution(struct iio_dev *indio_dev)
|
|
{
|
|
struct device_node *node = indio_dev->dev.of_node;
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
unsigned int i;
|
|
u32 res;
|
|
|
|
if (of_property_read_u32(node, "assigned-resolution-bits", &res))
|
|
res = adc->cfg->adc_info->resolutions[0];
|
|
|
|
for (i = 0; i < adc->cfg->adc_info->num_res; i++)
|
|
if (res == adc->cfg->adc_info->resolutions[i])
|
|
break;
|
|
if (i >= adc->cfg->adc_info->num_res) {
|
|
dev_err(&indio_dev->dev, "Bad resolution: %u bits\n", res);
|
|
return -EINVAL;
|
|
}
|
|
|
|
dev_dbg(&indio_dev->dev, "Using %u bits resolution\n", res);
|
|
adc->res = i;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void stm32_adc_smpr_init(struct stm32_adc *adc, int channel, u32 smp_ns)
|
|
{
|
|
const struct stm32_adc_regs *smpr = &adc->cfg->regs->smp_bits[channel];
|
|
u32 period_ns, shift = smpr->shift, mask = smpr->mask;
|
|
unsigned int smp, r = smpr->reg;
|
|
|
|
/* Determine sampling time (ADC clock cycles) */
|
|
period_ns = NSEC_PER_SEC / adc->common->rate;
|
|
for (smp = 0; smp <= STM32_ADC_MAX_SMP; smp++)
|
|
if ((period_ns * adc->cfg->smp_cycles[smp]) >= smp_ns)
|
|
break;
|
|
if (smp > STM32_ADC_MAX_SMP)
|
|
smp = STM32_ADC_MAX_SMP;
|
|
|
|
/* pre-build sampling time registers (e.g. smpr1, smpr2) */
|
|
adc->smpr_val[r] = (adc->smpr_val[r] & ~mask) | (smp << shift);
|
|
}
|
|
|
|
static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec *chan, u32 vinp,
|
|
u32 vinn, int scan_index, bool differential)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
char *name = adc->chan_name[vinp];
|
|
|
|
chan->type = IIO_VOLTAGE;
|
|
chan->channel = vinp;
|
|
if (differential) {
|
|
chan->differential = 1;
|
|
chan->channel2 = vinn;
|
|
snprintf(name, STM32_ADC_CH_SZ, "in%d-in%d", vinp, vinn);
|
|
} else {
|
|
snprintf(name, STM32_ADC_CH_SZ, "in%d", vinp);
|
|
}
|
|
chan->datasheet_name = name;
|
|
chan->scan_index = scan_index;
|
|
chan->indexed = 1;
|
|
chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
|
|
chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
|
|
BIT(IIO_CHAN_INFO_OFFSET);
|
|
chan->scan_type.sign = 'u';
|
|
chan->scan_type.realbits = adc->cfg->adc_info->resolutions[adc->res];
|
|
chan->scan_type.storagebits = 16;
|
|
chan->ext_info = stm32_adc_ext_info;
|
|
|
|
/* pre-build selected channels mask */
|
|
adc->pcsel |= BIT(chan->channel);
|
|
if (differential) {
|
|
/* pre-build diff channels mask */
|
|
adc->difsel |= BIT(chan->channel);
|
|
/* Also add negative input to pre-selected channels */
|
|
adc->pcsel |= BIT(chan->channel2);
|
|
}
|
|
}
|
|
|
|
static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
|
|
{
|
|
struct device_node *node = indio_dev->dev.of_node;
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
|
|
struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
|
|
struct property *prop;
|
|
const __be32 *cur;
|
|
struct iio_chan_spec *channels;
|
|
int scan_index = 0, num_channels = 0, num_diff = 0, ret, i;
|
|
u32 val, smp = 0;
|
|
|
|
ret = of_property_count_u32_elems(node, "st,adc-channels");
|
|
if (ret > adc_info->max_channels) {
|
|
dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
|
|
return -EINVAL;
|
|
} else if (ret > 0) {
|
|
num_channels += ret;
|
|
}
|
|
|
|
ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
|
|
sizeof(*diff));
|
|
if (ret > adc_info->max_channels) {
|
|
dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
|
|
return -EINVAL;
|
|
} else if (ret > 0) {
|
|
int size = ret * sizeof(*diff) / sizeof(u32);
|
|
|
|
num_diff = ret;
|
|
num_channels += ret;
|
|
ret = of_property_read_u32_array(node, "st,adc-diff-channels",
|
|
(u32 *)diff, size);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
if (!num_channels) {
|
|
dev_err(&indio_dev->dev, "No channels configured\n");
|
|
return -ENODATA;
|
|
}
|
|
|
|
/* Optional sample time is provided either for each, or all channels */
|
|
ret = of_property_count_u32_elems(node, "st,min-sample-time-nsecs");
|
|
if (ret > 1 && ret != num_channels) {
|
|
dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (timestamping)
|
|
num_channels++;
|
|
|
|
channels = devm_kcalloc(&indio_dev->dev, num_channels,
|
|
sizeof(struct iio_chan_spec), GFP_KERNEL);
|
|
if (!channels)
|
|
return -ENOMEM;
|
|
|
|
of_property_for_each_u32(node, "st,adc-channels", prop, cur, val) {
|
|
if (val >= adc_info->max_channels) {
|
|
dev_err(&indio_dev->dev, "Invalid channel %d\n", val);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Channel can't be configured both as single-ended & diff */
|
|
for (i = 0; i < num_diff; i++) {
|
|
if (val == diff[i].vinp) {
|
|
dev_err(&indio_dev->dev,
|
|
"channel %d miss-configured\n", val);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
|
|
0, scan_index, false);
|
|
scan_index++;
|
|
}
|
|
|
|
for (i = 0; i < num_diff; i++) {
|
|
if (diff[i].vinp >= adc_info->max_channels ||
|
|
diff[i].vinn >= adc_info->max_channels) {
|
|
dev_err(&indio_dev->dev, "Invalid channel in%d-in%d\n",
|
|
diff[i].vinp, diff[i].vinn);
|
|
return -EINVAL;
|
|
}
|
|
stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
|
|
diff[i].vinp, diff[i].vinn, scan_index,
|
|
true);
|
|
scan_index++;
|
|
}
|
|
|
|
for (i = 0; i < scan_index; i++) {
|
|
/*
|
|
* Using of_property_read_u32_index(), smp value will only be
|
|
* modified if valid u32 value can be decoded. This allows to
|
|
* get either no value, 1 shared value for all indexes, or one
|
|
* value per channel.
|
|
*/
|
|
of_property_read_u32_index(node, "st,min-sample-time-nsecs",
|
|
i, &smp);
|
|
/* Prepare sampling time settings */
|
|
stm32_adc_smpr_init(adc, channels[i].channel, smp);
|
|
}
|
|
|
|
if (timestamping) {
|
|
struct iio_chan_spec *timestamp = &channels[scan_index];
|
|
|
|
timestamp->type = IIO_TIMESTAMP;
|
|
timestamp->channel = -1;
|
|
timestamp->scan_index = scan_index;
|
|
timestamp->scan_type.sign = 's';
|
|
timestamp->scan_type.realbits = 64;
|
|
timestamp->scan_type.storagebits = 64;
|
|
|
|
scan_index++;
|
|
}
|
|
|
|
indio_dev->num_channels = scan_index;
|
|
indio_dev->channels = channels;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev)
|
|
{
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
struct dma_slave_config config;
|
|
int ret;
|
|
|
|
adc->dma_chan = dma_request_chan(dev, "rx");
|
|
if (IS_ERR(adc->dma_chan)) {
|
|
ret = PTR_ERR(adc->dma_chan);
|
|
if (ret != -ENODEV)
|
|
return dev_err_probe(dev, ret,
|
|
"DMA channel request failed with\n");
|
|
|
|
/* DMA is optional: fall back to IRQ mode */
|
|
adc->dma_chan = NULL;
|
|
return 0;
|
|
}
|
|
|
|
adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
|
|
STM32_DMA_BUFFER_SIZE,
|
|
&adc->rx_dma_buf, GFP_KERNEL);
|
|
if (!adc->rx_buf) {
|
|
ret = -ENOMEM;
|
|
goto err_release;
|
|
}
|
|
|
|
/* Configure DMA channel to read data register */
|
|
memset(&config, 0, sizeof(config));
|
|
config.src_addr = (dma_addr_t)adc->common->phys_base;
|
|
config.src_addr += adc->offset + adc->cfg->regs->dr;
|
|
config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
|
|
|
|
ret = dmaengine_slave_config(adc->dma_chan, &config);
|
|
if (ret)
|
|
goto err_free;
|
|
|
|
return 0;
|
|
|
|
err_free:
|
|
dma_free_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE,
|
|
adc->rx_buf, adc->rx_dma_buf);
|
|
err_release:
|
|
dma_release_channel(adc->dma_chan);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_adc_probe(struct platform_device *pdev)
|
|
{
|
|
struct iio_dev *indio_dev;
|
|
struct device *dev = &pdev->dev;
|
|
irqreturn_t (*handler)(int irq, void *p) = NULL;
|
|
struct stm32_adc *adc;
|
|
bool timestamping = false;
|
|
int ret;
|
|
|
|
if (!pdev->dev.of_node)
|
|
return -ENODEV;
|
|
|
|
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
|
|
if (!indio_dev)
|
|
return -ENOMEM;
|
|
|
|
adc = iio_priv(indio_dev);
|
|
adc->common = dev_get_drvdata(pdev->dev.parent);
|
|
spin_lock_init(&adc->lock);
|
|
init_completion(&adc->completion);
|
|
adc->cfg = (const struct stm32_adc_cfg *)
|
|
of_match_device(dev->driver->of_match_table, dev)->data;
|
|
|
|
indio_dev->name = dev_name(&pdev->dev);
|
|
indio_dev->dev.of_node = pdev->dev.of_node;
|
|
indio_dev->info = &stm32_adc_iio_info;
|
|
indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED;
|
|
|
|
platform_set_drvdata(pdev, indio_dev);
|
|
|
|
ret = of_property_read_u32(pdev->dev.of_node, "reg", &adc->offset);
|
|
if (ret != 0) {
|
|
dev_err(&pdev->dev, "missing reg property\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
adc->irq = platform_get_irq(pdev, 0);
|
|
if (adc->irq < 0)
|
|
return adc->irq;
|
|
|
|
ret = devm_request_threaded_irq(&pdev->dev, adc->irq, stm32_adc_isr,
|
|
stm32_adc_threaded_isr,
|
|
0, pdev->name, indio_dev);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "failed to request IRQ\n");
|
|
return ret;
|
|
}
|
|
|
|
adc->clk = devm_clk_get(&pdev->dev, NULL);
|
|
if (IS_ERR(adc->clk)) {
|
|
ret = PTR_ERR(adc->clk);
|
|
if (ret == -ENOENT && !adc->cfg->clk_required) {
|
|
adc->clk = NULL;
|
|
} else {
|
|
dev_err(&pdev->dev, "Can't get clock\n");
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ret = stm32_adc_of_get_resolution(indio_dev);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = stm32_adc_dma_request(dev, indio_dev);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (!adc->dma_chan) {
|
|
/* For PIO mode only, iio_pollfunc_store_time stores a timestamp
|
|
* in the primary trigger IRQ handler and stm32_adc_trigger_handler
|
|
* runs in the IRQ thread to push out buffer along with timestamp.
|
|
*/
|
|
handler = &stm32_adc_trigger_handler;
|
|
timestamping = true;
|
|
}
|
|
|
|
ret = stm32_adc_chan_of_init(indio_dev, timestamping);
|
|
if (ret < 0)
|
|
goto err_dma_disable;
|
|
|
|
ret = iio_triggered_buffer_setup(indio_dev,
|
|
&iio_pollfunc_store_time, handler,
|
|
&stm32_adc_buffer_setup_ops);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "buffer setup failed\n");
|
|
goto err_dma_disable;
|
|
}
|
|
|
|
/* Get stm32-adc-core PM online */
|
|
pm_runtime_get_noresume(dev);
|
|
pm_runtime_set_active(dev);
|
|
pm_runtime_set_autosuspend_delay(dev, STM32_ADC_HW_STOP_DELAY_MS);
|
|
pm_runtime_use_autosuspend(dev);
|
|
pm_runtime_enable(dev);
|
|
|
|
ret = stm32_adc_hw_start(dev);
|
|
if (ret)
|
|
goto err_buffer_cleanup;
|
|
|
|
ret = iio_device_register(indio_dev);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "iio dev register failed\n");
|
|
goto err_hw_stop;
|
|
}
|
|
|
|
pm_runtime_mark_last_busy(dev);
|
|
pm_runtime_put_autosuspend(dev);
|
|
|
|
return 0;
|
|
|
|
err_hw_stop:
|
|
stm32_adc_hw_stop(dev);
|
|
|
|
err_buffer_cleanup:
|
|
pm_runtime_disable(dev);
|
|
pm_runtime_set_suspended(dev);
|
|
pm_runtime_put_noidle(dev);
|
|
iio_triggered_buffer_cleanup(indio_dev);
|
|
|
|
err_dma_disable:
|
|
if (adc->dma_chan) {
|
|
dma_free_coherent(adc->dma_chan->device->dev,
|
|
STM32_DMA_BUFFER_SIZE,
|
|
adc->rx_buf, adc->rx_dma_buf);
|
|
dma_release_channel(adc->dma_chan);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_adc_remove(struct platform_device *pdev)
|
|
{
|
|
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
|
|
struct stm32_adc *adc = iio_priv(indio_dev);
|
|
|
|
pm_runtime_get_sync(&pdev->dev);
|
|
iio_device_unregister(indio_dev);
|
|
stm32_adc_hw_stop(&pdev->dev);
|
|
pm_runtime_disable(&pdev->dev);
|
|
pm_runtime_set_suspended(&pdev->dev);
|
|
pm_runtime_put_noidle(&pdev->dev);
|
|
iio_triggered_buffer_cleanup(indio_dev);
|
|
if (adc->dma_chan) {
|
|
dma_free_coherent(adc->dma_chan->device->dev,
|
|
STM32_DMA_BUFFER_SIZE,
|
|
adc->rx_buf, adc->rx_dma_buf);
|
|
dma_release_channel(adc->dma_chan);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#if defined(CONFIG_PM_SLEEP)
|
|
static int stm32_adc_suspend(struct device *dev)
|
|
{
|
|
struct iio_dev *indio_dev = dev_get_drvdata(dev);
|
|
|
|
if (iio_buffer_enabled(indio_dev))
|
|
stm32_adc_buffer_predisable(indio_dev);
|
|
|
|
return pm_runtime_force_suspend(dev);
|
|
}
|
|
|
|
static int stm32_adc_resume(struct device *dev)
|
|
{
|
|
struct iio_dev *indio_dev = dev_get_drvdata(dev);
|
|
int ret;
|
|
|
|
ret = pm_runtime_force_resume(dev);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (!iio_buffer_enabled(indio_dev))
|
|
return 0;
|
|
|
|
ret = stm32_adc_update_scan_mode(indio_dev,
|
|
indio_dev->active_scan_mask);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return stm32_adc_buffer_postenable(indio_dev);
|
|
}
|
|
#endif
|
|
|
|
#if defined(CONFIG_PM)
|
|
static int stm32_adc_runtime_suspend(struct device *dev)
|
|
{
|
|
return stm32_adc_hw_stop(dev);
|
|
}
|
|
|
|
static int stm32_adc_runtime_resume(struct device *dev)
|
|
{
|
|
return stm32_adc_hw_start(dev);
|
|
}
|
|
#endif
|
|
|
|
static const struct dev_pm_ops stm32_adc_pm_ops = {
|
|
SET_SYSTEM_SLEEP_PM_OPS(stm32_adc_suspend, stm32_adc_resume)
|
|
SET_RUNTIME_PM_OPS(stm32_adc_runtime_suspend, stm32_adc_runtime_resume,
|
|
NULL)
|
|
};
|
|
|
|
static const struct stm32_adc_cfg stm32f4_adc_cfg = {
|
|
.regs = &stm32f4_adc_regspec,
|
|
.adc_info = &stm32f4_adc_info,
|
|
.trigs = stm32f4_adc_trigs,
|
|
.clk_required = true,
|
|
.start_conv = stm32f4_adc_start_conv,
|
|
.stop_conv = stm32f4_adc_stop_conv,
|
|
.smp_cycles = stm32f4_adc_smp_cycles,
|
|
.irq_clear = stm32f4_adc_irq_clear,
|
|
};
|
|
|
|
static const struct stm32_adc_cfg stm32h7_adc_cfg = {
|
|
.regs = &stm32h7_adc_regspec,
|
|
.adc_info = &stm32h7_adc_info,
|
|
.trigs = stm32h7_adc_trigs,
|
|
.start_conv = stm32h7_adc_start_conv,
|
|
.stop_conv = stm32h7_adc_stop_conv,
|
|
.prepare = stm32h7_adc_prepare,
|
|
.unprepare = stm32h7_adc_unprepare,
|
|
.smp_cycles = stm32h7_adc_smp_cycles,
|
|
.irq_clear = stm32h7_adc_irq_clear,
|
|
};
|
|
|
|
static const struct stm32_adc_cfg stm32mp1_adc_cfg = {
|
|
.regs = &stm32h7_adc_regspec,
|
|
.adc_info = &stm32h7_adc_info,
|
|
.trigs = stm32h7_adc_trigs,
|
|
.has_vregready = true,
|
|
.start_conv = stm32h7_adc_start_conv,
|
|
.stop_conv = stm32h7_adc_stop_conv,
|
|
.prepare = stm32h7_adc_prepare,
|
|
.unprepare = stm32h7_adc_unprepare,
|
|
.smp_cycles = stm32h7_adc_smp_cycles,
|
|
.irq_clear = stm32h7_adc_irq_clear,
|
|
};
|
|
|
|
static const struct of_device_id stm32_adc_of_match[] = {
|
|
{ .compatible = "st,stm32f4-adc", .data = (void *)&stm32f4_adc_cfg },
|
|
{ .compatible = "st,stm32h7-adc", .data = (void *)&stm32h7_adc_cfg },
|
|
{ .compatible = "st,stm32mp1-adc", .data = (void *)&stm32mp1_adc_cfg },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, stm32_adc_of_match);
|
|
|
|
static struct platform_driver stm32_adc_driver = {
|
|
.probe = stm32_adc_probe,
|
|
.remove = stm32_adc_remove,
|
|
.driver = {
|
|
.name = "stm32-adc",
|
|
.of_match_table = stm32_adc_of_match,
|
|
.pm = &stm32_adc_pm_ops,
|
|
},
|
|
};
|
|
module_platform_driver(stm32_adc_driver);
|
|
|
|
MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
|
|
MODULE_DESCRIPTION("STMicroelectronics STM32 ADC IIO driver");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_ALIAS("platform:stm32-adc");
|