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![Johan Hovold](/assets/img/avatar_default.png)
On many Qualcomm platforms the PMIC RTC control and time registers are read-only so that the RTC time can not be updated. Instead an offset needs be stored in some machine-specific non-volatile memory, which the driver can take into account. Add support for storing a 32-bit offset from the Epoch in an nvmem cell so that the RTC time can be set on such platforms. Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20230202155448.6715-18-johan+linaro@kernel.org Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
554 lines
12 KiB
C
554 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* pm8xxx RTC driver
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*
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* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
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* Copyright (c) 2023, Linaro Limited
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*/
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#include <linux/of.h>
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#include <linux/module.h>
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#include <linux/nvmem-consumer.h>
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#include <linux/init.h>
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#include <linux/rtc.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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#include <linux/pm_wakeirq.h>
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#include <linux/regmap.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <asm/unaligned.h>
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/* RTC_CTRL register bit fields */
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#define PM8xxx_RTC_ENABLE BIT(7)
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#define PM8xxx_RTC_ALARM_CLEAR BIT(0)
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#define PM8xxx_RTC_ALARM_ENABLE BIT(7)
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#define NUM_8_BIT_RTC_REGS 0x4
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/**
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* struct pm8xxx_rtc_regs - describe RTC registers per PMIC versions
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* @ctrl: address of control register
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* @write: base address of write registers
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* @read: base address of read registers
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* @alarm_ctrl: address of alarm control register
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* @alarm_ctrl2: address of alarm control2 register
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* @alarm_rw: base address of alarm read-write registers
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* @alarm_en: alarm enable mask
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*/
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struct pm8xxx_rtc_regs {
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unsigned int ctrl;
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unsigned int write;
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unsigned int read;
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unsigned int alarm_ctrl;
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unsigned int alarm_ctrl2;
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unsigned int alarm_rw;
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unsigned int alarm_en;
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};
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/**
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* struct pm8xxx_rtc - RTC driver internal structure
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* @rtc: RTC device
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* @regmap: regmap used to access registers
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* @allow_set_time: whether the time can be set
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* @alarm_irq: alarm irq number
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* @regs: register description
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* @dev: device structure
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* @nvmem_cell: nvmem cell for offset
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* @offset: offset from epoch in seconds
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*/
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struct pm8xxx_rtc {
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struct rtc_device *rtc;
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struct regmap *regmap;
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bool allow_set_time;
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int alarm_irq;
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const struct pm8xxx_rtc_regs *regs;
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struct device *dev;
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struct nvmem_cell *nvmem_cell;
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u32 offset;
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};
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static int pm8xxx_rtc_read_nvmem_offset(struct pm8xxx_rtc *rtc_dd)
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{
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size_t len;
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void *buf;
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int rc;
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buf = nvmem_cell_read(rtc_dd->nvmem_cell, &len);
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if (IS_ERR(buf)) {
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rc = PTR_ERR(buf);
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dev_dbg(rtc_dd->dev, "failed to read nvmem offset: %d\n", rc);
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return rc;
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}
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if (len != sizeof(u32)) {
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dev_dbg(rtc_dd->dev, "unexpected nvmem cell size %zu\n", len);
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kfree(buf);
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return -EINVAL;
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}
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rtc_dd->offset = get_unaligned_le32(buf);
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kfree(buf);
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return 0;
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}
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static int pm8xxx_rtc_write_nvmem_offset(struct pm8xxx_rtc *rtc_dd, u32 offset)
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{
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u8 buf[sizeof(u32)];
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int rc;
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put_unaligned_le32(offset, buf);
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rc = nvmem_cell_write(rtc_dd->nvmem_cell, buf, sizeof(buf));
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if (rc < 0) {
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dev_dbg(rtc_dd->dev, "failed to write nvmem offset: %d\n", rc);
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return rc;
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}
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return 0;
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}
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static int pm8xxx_rtc_read_offset(struct pm8xxx_rtc *rtc_dd)
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{
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if (!rtc_dd->nvmem_cell)
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return 0;
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return pm8xxx_rtc_read_nvmem_offset(rtc_dd);
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}
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static int pm8xxx_rtc_read_raw(struct pm8xxx_rtc *rtc_dd, u32 *secs)
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{
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const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
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u8 value[NUM_8_BIT_RTC_REGS];
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unsigned int reg;
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int rc;
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rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value, sizeof(value));
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if (rc)
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return rc;
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/*
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* Read the LSB again and check if there has been a carry over.
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* If there has, redo the read operation.
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*/
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rc = regmap_read(rtc_dd->regmap, regs->read, ®);
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if (rc < 0)
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return rc;
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if (reg < value[0]) {
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rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value,
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sizeof(value));
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if (rc)
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return rc;
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}
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*secs = get_unaligned_le32(value);
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return 0;
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}
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static int pm8xxx_rtc_update_offset(struct pm8xxx_rtc *rtc_dd, u32 secs)
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{
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u32 raw_secs;
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u32 offset;
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int rc;
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if (!rtc_dd->nvmem_cell)
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return -ENODEV;
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rc = pm8xxx_rtc_read_raw(rtc_dd, &raw_secs);
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if (rc)
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return rc;
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offset = secs - raw_secs;
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if (offset == rtc_dd->offset)
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return 0;
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rc = pm8xxx_rtc_write_nvmem_offset(rtc_dd, offset);
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if (rc)
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return rc;
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rtc_dd->offset = offset;
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return 0;
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}
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/*
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* Steps to write the RTC registers.
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* 1. Disable alarm if enabled.
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* 2. Disable rtc if enabled.
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* 3. Write 0x00 to LSB.
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* 4. Write Byte[1], Byte[2], Byte[3] then Byte[0].
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* 5. Enable rtc if disabled in step 2.
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* 6. Enable alarm if disabled in step 1.
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*/
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static int __pm8xxx_rtc_set_time(struct pm8xxx_rtc *rtc_dd, u32 secs)
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{
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const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
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u8 value[NUM_8_BIT_RTC_REGS];
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bool alarm_enabled;
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int rc;
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put_unaligned_le32(secs, value);
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rc = regmap_update_bits_check(rtc_dd->regmap, regs->alarm_ctrl,
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regs->alarm_en, 0, &alarm_enabled);
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if (rc)
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return rc;
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/* Disable RTC */
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rc = regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE, 0);
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if (rc)
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return rc;
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/* Write 0 to Byte[0] */
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rc = regmap_write(rtc_dd->regmap, regs->write, 0);
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if (rc)
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return rc;
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/* Write Byte[1], Byte[2], Byte[3] */
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rc = regmap_bulk_write(rtc_dd->regmap, regs->write + 1,
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&value[1], sizeof(value) - 1);
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if (rc)
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return rc;
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/* Write Byte[0] */
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rc = regmap_write(rtc_dd->regmap, regs->write, value[0]);
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if (rc)
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return rc;
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/* Enable RTC */
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rc = regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE,
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PM8xxx_RTC_ENABLE);
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if (rc)
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return rc;
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if (alarm_enabled) {
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rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
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regs->alarm_en, regs->alarm_en);
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if (rc)
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return rc;
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}
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return 0;
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}
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static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
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u32 secs;
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int rc;
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secs = rtc_tm_to_time64(tm);
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if (rtc_dd->allow_set_time)
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rc = __pm8xxx_rtc_set_time(rtc_dd, secs);
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else
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rc = pm8xxx_rtc_update_offset(rtc_dd, secs);
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if (rc)
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return rc;
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dev_dbg(dev, "set time: %ptRd %ptRt (%u + %u)\n", tm, tm,
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secs - rtc_dd->offset, rtc_dd->offset);
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return 0;
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}
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static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
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u32 secs;
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int rc;
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rc = pm8xxx_rtc_read_raw(rtc_dd, &secs);
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if (rc)
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return rc;
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secs += rtc_dd->offset;
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rtc_time64_to_tm(secs, tm);
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dev_dbg(dev, "read time: %ptRd %ptRt (%u + %u)\n", tm, tm,
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secs - rtc_dd->offset, rtc_dd->offset);
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return 0;
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}
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static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
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{
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struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
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const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
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u8 value[NUM_8_BIT_RTC_REGS];
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u32 secs;
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int rc;
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secs = rtc_tm_to_time64(&alarm->time);
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secs -= rtc_dd->offset;
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put_unaligned_le32(secs, value);
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rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
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regs->alarm_en, 0);
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if (rc)
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return rc;
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rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value,
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sizeof(value));
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if (rc)
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return rc;
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if (alarm->enabled) {
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rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
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regs->alarm_en, regs->alarm_en);
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if (rc)
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return rc;
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}
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dev_dbg(dev, "set alarm: %ptRd %ptRt\n", &alarm->time, &alarm->time);
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return 0;
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}
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static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
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{
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struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
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const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
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u8 value[NUM_8_BIT_RTC_REGS];
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unsigned int ctrl_reg;
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u32 secs;
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int rc;
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rc = regmap_bulk_read(rtc_dd->regmap, regs->alarm_rw, value,
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sizeof(value));
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if (rc)
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return rc;
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secs = get_unaligned_le32(value);
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secs += rtc_dd->offset;
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rtc_time64_to_tm(secs, &alarm->time);
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rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
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if (rc)
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return rc;
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alarm->enabled = !!(ctrl_reg & PM8xxx_RTC_ALARM_ENABLE);
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dev_dbg(dev, "read alarm: %ptRd %ptRt\n", &alarm->time, &alarm->time);
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return 0;
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}
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static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
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{
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struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
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const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
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u8 value[NUM_8_BIT_RTC_REGS] = {0};
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unsigned int val;
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int rc;
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if (enable)
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val = regs->alarm_en;
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else
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val = 0;
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rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
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regs->alarm_en, val);
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if (rc)
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return rc;
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/* Clear alarm register */
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if (!enable) {
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rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value,
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sizeof(value));
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if (rc)
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return rc;
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}
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return 0;
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}
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static const struct rtc_class_ops pm8xxx_rtc_ops = {
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.read_time = pm8xxx_rtc_read_time,
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.set_time = pm8xxx_rtc_set_time,
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.set_alarm = pm8xxx_rtc_set_alarm,
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.read_alarm = pm8xxx_rtc_read_alarm,
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.alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
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};
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static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
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{
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struct pm8xxx_rtc *rtc_dd = dev_id;
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const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
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int rc;
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rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
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/* Disable alarm */
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rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
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regs->alarm_en, 0);
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if (rc)
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return IRQ_NONE;
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/* Clear alarm status */
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rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl2,
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PM8xxx_RTC_ALARM_CLEAR, 0);
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if (rc)
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return IRQ_NONE;
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return IRQ_HANDLED;
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}
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static int pm8xxx_rtc_enable(struct pm8xxx_rtc *rtc_dd)
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{
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const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
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return regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE,
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PM8xxx_RTC_ENABLE);
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}
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static const struct pm8xxx_rtc_regs pm8921_regs = {
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.ctrl = 0x11d,
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.write = 0x11f,
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.read = 0x123,
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.alarm_rw = 0x127,
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.alarm_ctrl = 0x11d,
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.alarm_ctrl2 = 0x11e,
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.alarm_en = BIT(1),
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};
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static const struct pm8xxx_rtc_regs pm8058_regs = {
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.ctrl = 0x1e8,
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.write = 0x1ea,
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.read = 0x1ee,
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.alarm_rw = 0x1f2,
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.alarm_ctrl = 0x1e8,
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.alarm_ctrl2 = 0x1e9,
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.alarm_en = BIT(1),
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};
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static const struct pm8xxx_rtc_regs pm8941_regs = {
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.ctrl = 0x6046,
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.write = 0x6040,
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.read = 0x6048,
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.alarm_rw = 0x6140,
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.alarm_ctrl = 0x6146,
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.alarm_ctrl2 = 0x6148,
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.alarm_en = BIT(7),
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};
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static const struct pm8xxx_rtc_regs pmk8350_regs = {
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.ctrl = 0x6146,
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.write = 0x6140,
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.read = 0x6148,
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.alarm_rw = 0x6240,
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.alarm_ctrl = 0x6246,
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.alarm_ctrl2 = 0x6248,
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.alarm_en = BIT(7),
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};
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static const struct of_device_id pm8xxx_id_table[] = {
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{ .compatible = "qcom,pm8921-rtc", .data = &pm8921_regs },
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{ .compatible = "qcom,pm8058-rtc", .data = &pm8058_regs },
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{ .compatible = "qcom,pm8941-rtc", .data = &pm8941_regs },
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{ .compatible = "qcom,pmk8350-rtc", .data = &pmk8350_regs },
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{ },
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};
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MODULE_DEVICE_TABLE(of, pm8xxx_id_table);
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static int pm8xxx_rtc_probe(struct platform_device *pdev)
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{
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const struct of_device_id *match;
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struct pm8xxx_rtc *rtc_dd;
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int rc;
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match = of_match_node(pm8xxx_id_table, pdev->dev.of_node);
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if (!match)
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return -ENXIO;
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rtc_dd = devm_kzalloc(&pdev->dev, sizeof(*rtc_dd), GFP_KERNEL);
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if (rtc_dd == NULL)
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return -ENOMEM;
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rtc_dd->regmap = dev_get_regmap(pdev->dev.parent, NULL);
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if (!rtc_dd->regmap)
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return -ENXIO;
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rtc_dd->alarm_irq = platform_get_irq(pdev, 0);
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if (rtc_dd->alarm_irq < 0)
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return -ENXIO;
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rtc_dd->allow_set_time = of_property_read_bool(pdev->dev.of_node,
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"allow-set-time");
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rtc_dd->nvmem_cell = devm_nvmem_cell_get(&pdev->dev, "offset");
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if (IS_ERR(rtc_dd->nvmem_cell)) {
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rc = PTR_ERR(rtc_dd->nvmem_cell);
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if (rc != -ENOENT)
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return rc;
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rtc_dd->nvmem_cell = NULL;
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}
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rtc_dd->regs = match->data;
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rtc_dd->dev = &pdev->dev;
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if (!rtc_dd->allow_set_time) {
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rc = pm8xxx_rtc_read_offset(rtc_dd);
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if (rc)
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return rc;
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}
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rc = pm8xxx_rtc_enable(rtc_dd);
|
|
if (rc)
|
|
return rc;
|
|
|
|
platform_set_drvdata(pdev, rtc_dd);
|
|
|
|
device_init_wakeup(&pdev->dev, 1);
|
|
|
|
rtc_dd->rtc = devm_rtc_allocate_device(&pdev->dev);
|
|
if (IS_ERR(rtc_dd->rtc))
|
|
return PTR_ERR(rtc_dd->rtc);
|
|
|
|
rtc_dd->rtc->ops = &pm8xxx_rtc_ops;
|
|
rtc_dd->rtc->range_max = U32_MAX;
|
|
|
|
rc = devm_request_any_context_irq(&pdev->dev, rtc_dd->alarm_irq,
|
|
pm8xxx_alarm_trigger,
|
|
IRQF_TRIGGER_RISING,
|
|
"pm8xxx_rtc_alarm", rtc_dd);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
rc = devm_rtc_register_device(rtc_dd->rtc);
|
|
if (rc)
|
|
return rc;
|
|
|
|
rc = dev_pm_set_wake_irq(&pdev->dev, rtc_dd->alarm_irq);
|
|
if (rc)
|
|
return rc;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pm8xxx_remove(struct platform_device *pdev)
|
|
{
|
|
dev_pm_clear_wake_irq(&pdev->dev);
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver pm8xxx_rtc_driver = {
|
|
.probe = pm8xxx_rtc_probe,
|
|
.remove = pm8xxx_remove,
|
|
.driver = {
|
|
.name = "rtc-pm8xxx",
|
|
.of_match_table = pm8xxx_id_table,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(pm8xxx_rtc_driver);
|
|
|
|
MODULE_ALIAS("platform:rtc-pm8xxx");
|
|
MODULE_DESCRIPTION("PMIC8xxx RTC driver");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>");
|
|
MODULE_AUTHOR("Johan Hovold <johan@kernel.org>");
|