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![Lars-Peter Clausen](/assets/img/avatar_default.png)
Use DIV_ROUND_CLOSEST() instead of open-coding it. This documents intent and makes it more clear what is going on for the casual reviewer. Generated using the following the Coccinelle semantic patch. // <smpl> @r1@ expression x; constant C1; constant C2; @@ ((x) + C1) / C2 @script:python@ C1 << r1.C1; C2 << r1.C2; @@ try: if int(C1) * 2 != int(C2): cocci.include_match(False) except: cocci.include_match(False) @@ expression r1.x; constant r1.C1; constant r1.C2; @@ -(((x) + C1) / C2) +DIV_ROUND_CLOSEST(x, C2) // </smpl> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Manivannan Sadhasivam <mani@kernel.org> Link: https://lore.kernel.org/r/20201227171126.28216-1-lars@metafoo.de Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
551 lines
13 KiB
C
551 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* vl6180.c - Support for STMicroelectronics VL6180 ALS, range and proximity
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* sensor
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*
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* Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
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* Copyright 2017 Manivannan Sadhasivam <manivannanece23@gmail.com>
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*
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* IIO driver for VL6180 (7-bit I2C slave address 0x29)
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*
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* Range: 0 to 100mm
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* ALS: < 1 Lux up to 100 kLux
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* IR: 850nm
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*
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* TODO: irq, threshold events, continuous mode, hardware buffer
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*/
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/i2c.h>
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#include <linux/mutex.h>
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#include <linux/err.h>
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#include <linux/of.h>
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#include <linux/delay.h>
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#include <linux/util_macros.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#define VL6180_DRV_NAME "vl6180"
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/* Device identification register and value */
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#define VL6180_MODEL_ID 0x000
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#define VL6180_MODEL_ID_VAL 0xb4
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/* Configuration registers */
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#define VL6180_INTR_CONFIG 0x014
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#define VL6180_INTR_CLEAR 0x015
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#define VL6180_OUT_OF_RESET 0x016
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#define VL6180_HOLD 0x017
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#define VL6180_RANGE_START 0x018
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#define VL6180_ALS_START 0x038
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#define VL6180_ALS_GAIN 0x03f
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#define VL6180_ALS_IT 0x040
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/* Status registers */
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#define VL6180_RANGE_STATUS 0x04d
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#define VL6180_ALS_STATUS 0x04e
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#define VL6180_INTR_STATUS 0x04f
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/* Result value registers */
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#define VL6180_ALS_VALUE 0x050
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#define VL6180_RANGE_VALUE 0x062
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#define VL6180_RANGE_RATE 0x066
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/* bits of the RANGE_START and ALS_START register */
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#define VL6180_MODE_CONT BIT(1) /* continuous mode */
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#define VL6180_STARTSTOP BIT(0) /* start measurement, auto-reset */
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/* bits of the INTR_STATUS and INTR_CONFIG register */
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#define VL6180_ALS_READY BIT(5)
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#define VL6180_RANGE_READY BIT(2)
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/* bits of the INTR_CLEAR register */
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#define VL6180_CLEAR_ERROR BIT(2)
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#define VL6180_CLEAR_ALS BIT(1)
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#define VL6180_CLEAR_RANGE BIT(0)
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/* bits of the HOLD register */
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#define VL6180_HOLD_ON BIT(0)
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/* default value for the ALS_IT register */
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#define VL6180_ALS_IT_100 0x63 /* 100 ms */
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/* values for the ALS_GAIN register */
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#define VL6180_ALS_GAIN_1 0x46
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#define VL6180_ALS_GAIN_1_25 0x45
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#define VL6180_ALS_GAIN_1_67 0x44
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#define VL6180_ALS_GAIN_2_5 0x43
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#define VL6180_ALS_GAIN_5 0x42
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#define VL6180_ALS_GAIN_10 0x41
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#define VL6180_ALS_GAIN_20 0x40
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#define VL6180_ALS_GAIN_40 0x47
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struct vl6180_data {
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struct i2c_client *client;
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struct mutex lock;
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unsigned int als_gain_milli;
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unsigned int als_it_ms;
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};
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enum { VL6180_ALS, VL6180_RANGE, VL6180_PROX };
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/**
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* struct vl6180_chan_regs - Registers for accessing channels
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* @drdy_mask: Data ready bit in status register
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* @start_reg: Conversion start register
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* @value_reg: Result value register
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* @word: Register word length
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*/
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struct vl6180_chan_regs {
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u8 drdy_mask;
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u16 start_reg, value_reg;
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bool word;
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};
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static const struct vl6180_chan_regs vl6180_chan_regs_table[] = {
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[VL6180_ALS] = {
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.drdy_mask = VL6180_ALS_READY,
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.start_reg = VL6180_ALS_START,
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.value_reg = VL6180_ALS_VALUE,
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.word = true,
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},
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[VL6180_RANGE] = {
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.drdy_mask = VL6180_RANGE_READY,
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.start_reg = VL6180_RANGE_START,
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.value_reg = VL6180_RANGE_VALUE,
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.word = false,
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},
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[VL6180_PROX] = {
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.drdy_mask = VL6180_RANGE_READY,
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.start_reg = VL6180_RANGE_START,
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.value_reg = VL6180_RANGE_RATE,
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.word = true,
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},
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};
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static int vl6180_read(struct i2c_client *client, u16 cmd, void *databuf,
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u8 len)
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{
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__be16 cmdbuf = cpu_to_be16(cmd);
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struct i2c_msg msgs[2] = {
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{ .addr = client->addr, .len = sizeof(cmdbuf), .buf = (u8 *) &cmdbuf },
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{ .addr = client->addr, .len = len, .buf = databuf,
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.flags = I2C_M_RD } };
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int ret;
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ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
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if (ret < 0)
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dev_err(&client->dev, "failed reading register 0x%04x\n", cmd);
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return ret;
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}
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static int vl6180_read_byte(struct i2c_client *client, u16 cmd)
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{
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u8 data;
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int ret;
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ret = vl6180_read(client, cmd, &data, sizeof(data));
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if (ret < 0)
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return ret;
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return data;
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}
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static int vl6180_read_word(struct i2c_client *client, u16 cmd)
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{
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__be16 data;
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int ret;
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ret = vl6180_read(client, cmd, &data, sizeof(data));
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if (ret < 0)
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return ret;
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return be16_to_cpu(data);
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}
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static int vl6180_write_byte(struct i2c_client *client, u16 cmd, u8 val)
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{
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u8 buf[3];
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struct i2c_msg msgs[1] = {
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{ .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } };
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int ret;
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buf[0] = cmd >> 8;
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buf[1] = cmd & 0xff;
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buf[2] = val;
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ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
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if (ret < 0) {
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dev_err(&client->dev, "failed writing register 0x%04x\n", cmd);
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return ret;
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}
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return 0;
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}
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static int vl6180_write_word(struct i2c_client *client, u16 cmd, u16 val)
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{
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__be16 buf[2];
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struct i2c_msg msgs[1] = {
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{ .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } };
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int ret;
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buf[0] = cpu_to_be16(cmd);
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buf[1] = cpu_to_be16(val);
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ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
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if (ret < 0) {
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dev_err(&client->dev, "failed writing register 0x%04x\n", cmd);
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return ret;
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}
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return 0;
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}
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static int vl6180_measure(struct vl6180_data *data, int addr)
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{
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struct i2c_client *client = data->client;
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int tries = 20, ret;
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u16 value;
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mutex_lock(&data->lock);
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/* Start single shot measurement */
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ret = vl6180_write_byte(client,
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vl6180_chan_regs_table[addr].start_reg, VL6180_STARTSTOP);
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if (ret < 0)
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goto fail;
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while (tries--) {
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ret = vl6180_read_byte(client, VL6180_INTR_STATUS);
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if (ret < 0)
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goto fail;
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if (ret & vl6180_chan_regs_table[addr].drdy_mask)
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break;
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msleep(20);
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}
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if (tries < 0) {
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ret = -EIO;
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goto fail;
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}
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/* Read result value from appropriate registers */
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ret = vl6180_chan_regs_table[addr].word ?
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vl6180_read_word(client, vl6180_chan_regs_table[addr].value_reg) :
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vl6180_read_byte(client, vl6180_chan_regs_table[addr].value_reg);
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if (ret < 0)
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goto fail;
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value = ret;
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/* Clear the interrupt flag after data read */
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ret = vl6180_write_byte(client, VL6180_INTR_CLEAR,
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VL6180_CLEAR_ERROR | VL6180_CLEAR_ALS | VL6180_CLEAR_RANGE);
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if (ret < 0)
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goto fail;
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ret = value;
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fail:
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mutex_unlock(&data->lock);
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return ret;
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}
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static const struct iio_chan_spec vl6180_channels[] = {
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{
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.type = IIO_LIGHT,
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.address = VL6180_ALS,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
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BIT(IIO_CHAN_INFO_INT_TIME) |
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BIT(IIO_CHAN_INFO_SCALE) |
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BIT(IIO_CHAN_INFO_HARDWAREGAIN),
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}, {
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.type = IIO_DISTANCE,
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.address = VL6180_RANGE,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
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BIT(IIO_CHAN_INFO_SCALE),
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}, {
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.type = IIO_PROXIMITY,
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.address = VL6180_PROX,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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}
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};
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/*
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* Available Ambient Light Sensor gain settings, 1/1000th, and
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* corresponding setting for the VL6180_ALS_GAIN register
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*/
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static const int vl6180_als_gain_tab[8] = {
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1000, 1250, 1670, 2500, 5000, 10000, 20000, 40000
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};
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static const u8 vl6180_als_gain_tab_bits[8] = {
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VL6180_ALS_GAIN_1, VL6180_ALS_GAIN_1_25,
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VL6180_ALS_GAIN_1_67, VL6180_ALS_GAIN_2_5,
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VL6180_ALS_GAIN_5, VL6180_ALS_GAIN_10,
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VL6180_ALS_GAIN_20, VL6180_ALS_GAIN_40
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};
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static int vl6180_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct vl6180_data *data = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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ret = vl6180_measure(data, chan->address);
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if (ret < 0)
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return ret;
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*val = ret;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_INT_TIME:
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*val = data->als_it_ms;
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*val2 = 1000;
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return IIO_VAL_FRACTIONAL;
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case IIO_CHAN_INFO_SCALE:
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switch (chan->type) {
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case IIO_LIGHT:
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/* one ALS count is 0.32 Lux @ gain 1, IT 100 ms */
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*val = 32000; /* 0.32 * 1000 * 100 */
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*val2 = data->als_gain_milli * data->als_it_ms;
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return IIO_VAL_FRACTIONAL;
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case IIO_DISTANCE:
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*val = 0; /* sensor reports mm, scale to meter */
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*val2 = 1000;
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break;
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default:
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return -EINVAL;
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}
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return IIO_VAL_INT_PLUS_MICRO;
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case IIO_CHAN_INFO_HARDWAREGAIN:
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*val = data->als_gain_milli;
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*val2 = 1000;
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return IIO_VAL_FRACTIONAL;
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default:
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return -EINVAL;
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}
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}
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static IIO_CONST_ATTR(als_gain_available, "1 1.25 1.67 2.5 5 10 20 40");
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static struct attribute *vl6180_attributes[] = {
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&iio_const_attr_als_gain_available.dev_attr.attr,
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NULL
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};
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static const struct attribute_group vl6180_attribute_group = {
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.attrs = vl6180_attributes,
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};
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/* HOLD is needed before updating any config registers */
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static int vl6180_hold(struct vl6180_data *data, bool hold)
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{
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return vl6180_write_byte(data->client, VL6180_HOLD,
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hold ? VL6180_HOLD_ON : 0);
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}
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static int vl6180_set_als_gain(struct vl6180_data *data, int val, int val2)
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{
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int i, ret, gain;
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if (val < 1 || val > 40)
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return -EINVAL;
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gain = (val * 1000000 + val2) / 1000;
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if (gain < 1 || gain > 40000)
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return -EINVAL;
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i = find_closest(gain, vl6180_als_gain_tab,
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ARRAY_SIZE(vl6180_als_gain_tab));
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mutex_lock(&data->lock);
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ret = vl6180_hold(data, true);
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if (ret < 0)
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goto fail;
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ret = vl6180_write_byte(data->client, VL6180_ALS_GAIN,
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vl6180_als_gain_tab_bits[i]);
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if (ret >= 0)
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data->als_gain_milli = vl6180_als_gain_tab[i];
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fail:
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vl6180_hold(data, false);
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mutex_unlock(&data->lock);
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return ret;
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}
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static int vl6180_set_it(struct vl6180_data *data, int val, int val2)
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{
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int ret, it_ms;
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it_ms = DIV_ROUND_CLOSEST(val2, 1000); /* round to ms */
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if (val != 0 || it_ms < 1 || it_ms > 512)
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return -EINVAL;
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mutex_lock(&data->lock);
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ret = vl6180_hold(data, true);
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if (ret < 0)
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goto fail;
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ret = vl6180_write_word(data->client, VL6180_ALS_IT, it_ms - 1);
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if (ret >= 0)
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data->als_it_ms = it_ms;
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fail:
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vl6180_hold(data, false);
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mutex_unlock(&data->lock);
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return ret;
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}
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static int vl6180_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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struct vl6180_data *data = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_INT_TIME:
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return vl6180_set_it(data, val, val2);
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case IIO_CHAN_INFO_HARDWAREGAIN:
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if (chan->type != IIO_LIGHT)
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return -EINVAL;
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return vl6180_set_als_gain(data, val, val2);
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default:
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return -EINVAL;
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}
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}
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static const struct iio_info vl6180_info = {
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.read_raw = vl6180_read_raw,
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.write_raw = vl6180_write_raw,
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.attrs = &vl6180_attribute_group,
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};
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static int vl6180_init(struct vl6180_data *data)
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{
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struct i2c_client *client = data->client;
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int ret;
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ret = vl6180_read_byte(client, VL6180_MODEL_ID);
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if (ret < 0)
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return ret;
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if (ret != VL6180_MODEL_ID_VAL) {
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dev_err(&client->dev, "invalid model ID %02x\n", ret);
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return -ENODEV;
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}
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ret = vl6180_hold(data, true);
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if (ret < 0)
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return ret;
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ret = vl6180_read_byte(client, VL6180_OUT_OF_RESET);
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if (ret < 0)
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return ret;
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/*
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* Detect false reset condition here. This bit is always set when the
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* system comes out of reset.
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*/
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if (ret != 0x01)
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dev_info(&client->dev, "device is not fresh out of reset\n");
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/* Enable ALS and Range ready interrupts */
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ret = vl6180_write_byte(client, VL6180_INTR_CONFIG,
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VL6180_ALS_READY | VL6180_RANGE_READY);
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if (ret < 0)
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return ret;
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/* ALS integration time: 100ms */
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data->als_it_ms = 100;
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ret = vl6180_write_word(client, VL6180_ALS_IT, VL6180_ALS_IT_100);
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if (ret < 0)
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return ret;
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/* ALS gain: 1 */
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data->als_gain_milli = 1000;
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ret = vl6180_write_byte(client, VL6180_ALS_GAIN, VL6180_ALS_GAIN_1);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = vl6180_write_byte(client, VL6180_OUT_OF_RESET, 0x00);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return vl6180_hold(data, false);
|
|
}
|
|
|
|
static int vl6180_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct vl6180_data *data;
|
|
struct iio_dev *indio_dev;
|
|
int ret;
|
|
|
|
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
|
|
if (!indio_dev)
|
|
return -ENOMEM;
|
|
|
|
data = iio_priv(indio_dev);
|
|
i2c_set_clientdata(client, indio_dev);
|
|
data->client = client;
|
|
mutex_init(&data->lock);
|
|
|
|
indio_dev->info = &vl6180_info;
|
|
indio_dev->channels = vl6180_channels;
|
|
indio_dev->num_channels = ARRAY_SIZE(vl6180_channels);
|
|
indio_dev->name = VL6180_DRV_NAME;
|
|
indio_dev->modes = INDIO_DIRECT_MODE;
|
|
|
|
ret = vl6180_init(data);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return devm_iio_device_register(&client->dev, indio_dev);
|
|
}
|
|
|
|
static const struct of_device_id vl6180_of_match[] = {
|
|
{ .compatible = "st,vl6180", },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, vl6180_of_match);
|
|
|
|
static const struct i2c_device_id vl6180_id[] = {
|
|
{ "vl6180", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, vl6180_id);
|
|
|
|
static struct i2c_driver vl6180_driver = {
|
|
.driver = {
|
|
.name = VL6180_DRV_NAME,
|
|
.of_match_table = vl6180_of_match,
|
|
},
|
|
.probe = vl6180_probe,
|
|
.id_table = vl6180_id,
|
|
};
|
|
|
|
module_i2c_driver(vl6180_driver);
|
|
|
|
MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
|
|
MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>");
|
|
MODULE_DESCRIPTION("STMicro VL6180 ALS, range and proximity sensor driver");
|
|
MODULE_LICENSE("GPL");
|