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// SPDX-License-Identifier: GPL-2.0-only
/*
* mag3110.c - Support for Freescale MAG3110 magnetometer sensor
*
* Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
*
* (7-bit I2C slave address 0x0e)
*
* TODO: irq, user offset, oversampling, continuous mode
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/delay.h>
#include <linux/regulator/consumer.h>
#define MAG3110_STATUS 0x00
#define MAG3110_OUT_X 0x01 /* MSB first */
#define MAG3110_OUT_Y 0x03
#define MAG3110_OUT_Z 0x05
#define MAG3110_WHO_AM_I 0x07
#define MAG3110_SYSMOD 0x08
#define MAG3110_OFF_X 0x09 /* MSB first */
#define MAG3110_OFF_Y 0x0b
#define MAG3110_OFF_Z 0x0d
#define MAG3110_DIE_TEMP 0x0f
#define MAG3110_CTRL_REG1 0x10
#define MAG3110_CTRL_REG2 0x11
#define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
#define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5))
#define MAG3110_CTRL_DR_SHIFT 5
#define MAG3110_CTRL_DR_DEFAULT 0
#define MAG3110_SYSMOD_MODE_MASK GENMASK(1, 0)
#define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */
#define MAG3110_CTRL_AC BIT(0) /* continuous measurements */
#define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */
#define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */
#define MAG3110_DEVICE_ID 0xc4
/* Each client has this additional data */
struct mag3110_data {
struct i2c_client *client;
struct mutex lock;
u8 ctrl_reg1;
int sleep_val;
struct regulator *vdd_reg;
struct regulator *vddio_reg;
};
static int mag3110_request(struct mag3110_data *data)
{
int ret, tries = 150;
if ((data->ctrl_reg1 & MAG3110_CTRL_AC) == 0) {
/* trigger measurement */
ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
data->ctrl_reg1 | MAG3110_CTRL_TM);
if (ret < 0)
return ret;
}
while (tries-- > 0) {
ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
if (ret < 0)
return ret;
/* wait for data ready */
if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
break;
if (data->sleep_val <= 20)
usleep_range(data->sleep_val * 250, data->sleep_val * 500);
else
msleep(20);
}
if (tries < 0) {
dev_err(&data->client->dev, "data not ready\n");
return -EIO;
}
return 0;
}
static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
{
int ret;
mutex_lock(&data->lock);
ret = mag3110_request(data);
if (ret < 0) {
mutex_unlock(&data->lock);
return ret;
}
ret = i2c_smbus_read_i2c_block_data(data->client,
MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
mutex_unlock(&data->lock);
return ret;
}
static ssize_t mag3110_show_int_plus_micros(char *buf,
const int (*vals)[2], int n)
{
size_t len = 0;
while (n-- > 0)
len += scnprintf(buf + len, PAGE_SIZE - len,
"%d.%06d ", vals[n][0], vals[n][1]);
/* replace trailing space by newline */
buf[len - 1] = '\n';
return len;
}
static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
int val, int val2)
{
while (n-- > 0)
if (val == vals[n][0] && val2 == vals[n][1])
return n;
return -EINVAL;
}
static const int mag3110_samp_freq[8][2] = {
{80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
{1, 250000}, {0, 625000}
};
static ssize_t mag3110_show_samp_freq_avail(struct device *dev,
struct device_attribute *attr, char *buf)
{
return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);
}
static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);
static int mag3110_get_samp_freq_index(struct mag3110_data *data,
int val, int val2)
{
return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,
val2);
}
static int mag3110_calculate_sleep(struct mag3110_data *data)
{
int ret, i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
if (mag3110_samp_freq[i][0] > 0)
ret = 1000 / mag3110_samp_freq[i][0];
else
ret = 1000;
return ret == 0 ? 1 : ret;
}
static int mag3110_standby(struct mag3110_data *data)
{
return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
data->ctrl_reg1 & ~MAG3110_CTRL_AC);
}
static int mag3110_wait_standby(struct mag3110_data *data)
{
int ret, tries = 30;
/*
* Takes up to 1/ODR to come out of active mode into stby
* Longest expected period is 12.5seconds.
* We'll sleep for 500ms between checks
*/
while (tries-- > 0) {
ret = i2c_smbus_read_byte_data(data->client, MAG3110_SYSMOD);
if (ret < 0) {
dev_err(&data->client->dev, "i2c error\n");
return ret;
}
/* wait for standby */
if ((ret & MAG3110_SYSMOD_MODE_MASK) == 0)
break;
msleep_interruptible(500);
}
if (tries < 0) {
dev_err(&data->client->dev, "device not entering standby mode\n");
return -EIO;
}
return 0;
}
static int mag3110_active(struct mag3110_data *data)
{
return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
data->ctrl_reg1);
}
/* returns >0 if active, 0 if in standby and <0 on error */
static int mag3110_is_active(struct mag3110_data *data)
{
int reg;
reg = i2c_smbus_read_byte_data(data->client, MAG3110_CTRL_REG1);
if (reg < 0)
return reg;
return reg & MAG3110_CTRL_AC;
}
static int mag3110_change_config(struct mag3110_data *data, u8 reg, u8 val)
{
int ret;
int is_active;
mutex_lock(&data->lock);
is_active = mag3110_is_active(data);
if (is_active < 0) {
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