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linux/drivers/iio/magnetometer/ak8975.c

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/*
* A sensor driver for the magnetometer AK8975.
*
* Magnetic compass sensor driver for monitoring magnetic flux information.
*
* Copyright (c) 2010, NVIDIA Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/acpi.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/magnetometer/ak8975.h>
/*
* Register definitions, as well as various shifts and masks to get at the
* individual fields of the registers.
*/
#define AK8975_REG_WIA 0x00
#define AK8975_DEVICE_ID 0x48
#define AK8975_REG_INFO 0x01
#define AK8975_REG_ST1 0x02
#define AK8975_REG_ST1_DRDY_SHIFT 0
#define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT)
#define AK8975_REG_HXL 0x03
#define AK8975_REG_HXH 0x04
#define AK8975_REG_HYL 0x05
#define AK8975_REG_HYH 0x06
#define AK8975_REG_HZL 0x07
#define AK8975_REG_HZH 0x08
#define AK8975_REG_ST2 0x09
#define AK8975_REG_ST2_DERR_SHIFT 2
#define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT)
#define AK8975_REG_ST2_HOFL_SHIFT 3
#define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT)
#define AK8975_REG_CNTL 0x0A
#define AK8975_REG_CNTL_MODE_SHIFT 0
#define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT)
#define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00
#define AK8975_REG_CNTL_MODE_ONCE 0x01
#define AK8975_REG_CNTL_MODE_SELF_TEST 0x08
#define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F
#define AK8975_REG_RSVC 0x0B
#define AK8975_REG_ASTC 0x0C
#define AK8975_REG_TS1 0x0D
#define AK8975_REG_TS2 0x0E
#define AK8975_REG_I2CDIS 0x0F
#define AK8975_REG_ASAX 0x10
#define AK8975_REG_ASAY 0x11
#define AK8975_REG_ASAZ 0x12
#define AK8975_MAX_REGS AK8975_REG_ASAZ
/*
* AK09912 Register definitions
*/
#define AK09912_REG_WIA1 0x00
#define AK09912_REG_WIA2 0x01
#define AK09912_DEVICE_ID 0x04
#define AK09911_DEVICE_ID 0x05
#define AK09911_REG_INFO1 0x02
#define AK09911_REG_INFO2 0x03
#define AK09912_REG_ST1 0x10
#define AK09912_REG_ST1_DRDY_SHIFT 0
#define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT)
#define AK09912_REG_HXL 0x11
#define AK09912_REG_HXH 0x12
#define AK09912_REG_HYL 0x13
#define AK09912_REG_HYH 0x14
#define AK09912_REG_HZL 0x15
#define AK09912_REG_HZH 0x16
#define AK09912_REG_TMPS 0x17
#define AK09912_REG_ST2 0x18
#define AK09912_REG_ST2_HOFL_SHIFT 3
#define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT)
#define AK09912_REG_CNTL1 0x30
#define AK09912_REG_CNTL2 0x31
#define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00
#define AK09912_REG_CNTL_MODE_ONCE 0x01
#define AK09912_REG_CNTL_MODE_SELF_TEST 0x10
#define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F
#define AK09912_REG_CNTL2_MODE_SHIFT 0
#define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT)
#define AK09912_REG_CNTL3 0x32
#define AK09912_REG_TS1 0x33
#define AK09912_REG_TS2 0x34
#define AK09912_REG_TS3 0x35
#define AK09912_REG_I2CDIS 0x36
#define AK09912_REG_TS4 0x37
#define AK09912_REG_ASAX 0x60
#define AK09912_REG_ASAY 0x61
#define AK09912_REG_ASAZ 0x62
#define AK09912_MAX_REGS AK09912_REG_ASAZ
/*
* Miscellaneous values.
*/
#define AK8975_MAX_CONVERSION_TIMEOUT 500
#define AK8975_CONVERSION_DONE_POLL_TIME 10
#define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000)
/*
* Precalculate scale factor (in Gauss units) for each axis and
* store in the device data.
*
* This scale factor is axis-dependent, and is derived from 3 calibration
* factors ASA(x), ASA(y), and ASA(z).
*
* These ASA values are read from the sensor device at start of day, and
* cached in the device context struct.
*
* Adjusting the flux value with the sensitivity adjustment value should be
* done via the following formula:
*
* Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 )
* where H is the raw value, ASA is the sensitivity adjustment, and Hadj
* is the resultant adjusted value.
*
* We reduce the formula to:
*
* Hadj = H * (ASA + 128) / 256
*
* H is in the range of -4096 to 4095. The magnetometer has a range of
* +-1229uT. To go from the raw value to uT is:
*
* HuT = H * 1229/4096, or roughly, 3/10.
*
* Since 1uT = 0.01 gauss, our final scale factor becomes:
*
* Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100
* Hadj = H * ((ASA + 128) * 0.003) / 256
*
* Since ASA doesn't change, we cache the resultant scale factor into the
* device context in ak8975_setup().
*
* Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we
* multiply the stored scale value by 1e6.
*/
static long ak8975_raw_to_gauss(u16 data)
{
return (((long)data + 128) * 3000) / 256;
}
/*
* For AK8963 and AK09911, same calculation, but the device is less sensitive:
*
* H is in the range of +-8190. The magnetometer has a range of
* +-4912uT. To go from the raw value to uT is:
*
* HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10.
*/
static long ak8963_09911_raw_to_gauss(u16 data)
{
return (((long)data + 128) * 6000) / 256;
}
/*
* For AK09912, same calculation, except the device is more sensitive:
*
* H is in the range of -32752 to 32752. The magnetometer has a range of
* +-4912uT. To go from the raw value to uT is:
*
* HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10.
*/
static long ak09912_raw_to_gauss(u16 data)
{
return (((long)data + 128) * 1500) / 256;
}
/* Compatible Asahi Kasei Compass parts */
enum asahi_compass_chipset {
AK8975,
AK8963,
AK09911,
AK09912,
AK_MAX_TYPE
};
enum ak_ctrl_reg_addr {
ST1,
ST2,
CNTL,
ASA_BASE,
MAX_REGS,
REGS_END,
};
enum ak_ctrl_reg_mask {
ST1_DRDY,
ST2_HOFL,
ST2_DERR,
CNTL_MODE,
MASK_END,
};
enum ak_ctrl_mode {
POWER_DOWN,
MODE_ONCE,
SELF_TEST,
FUSE_ROM,
MODE_END,
};
struct ak_def {
enum asahi_compass_chipset type;
long (*raw_to_gauss)(u16 data);
u16 range;
u8 ctrl_regs[REGS_END];
u8 ctrl_masks[MASK_END];
u8 ctrl_modes[MODE_END];
u8 data_regs[3];
};
static const struct ak_def ak_def_array[AK_MAX_TYPE] = {
{
.type = AK8975,
.raw_to_gauss = ak8975_raw_to_gauss,
.range = 4096,
.ctrl_regs = {
AK8975_REG_ST1,
AK8975_REG_ST2,
AK8975_REG_CNTL,
AK8975_REG_ASAX,
AK8975_MAX_REGS},
.ctrl_masks = {
AK8975_REG_ST1_DRDY_MASK,
AK8975_REG_ST2_HOFL_MASK,
AK8975_REG_ST2_DERR_MASK,
AK8975_REG_CNTL_MODE_MASK},
.ctrl_modes = {
AK8975_REG_CNTL_MODE_POWER_DOWN,
AK8975_REG_CNTL_MODE_ONCE,
AK8975_REG_CNTL_MODE_SELF_TEST,
AK8975_REG_CNTL_MODE_FUSE_ROM},
.data_regs = {
AK8975_REG_HXL,
AK8975_REG_HYL,
AK8975_REG_HZL},
},
{
.type = AK8963,
.raw_to_gauss = ak8963_09911_raw_to_gauss,
.range = 8190,
.ctrl_regs = {
AK8975_REG_ST1,
AK8975_REG_ST2,
AK8975_REG_CNTL,
AK8975_REG_ASAX,
AK8975_MAX_REGS},
.ctrl_masks = {
AK8975_REG_ST1_DRDY_MASK,
AK8975_REG_ST2_HOFL_MASK,
0,
AK8975_REG_CNTL_MODE_MASK},
.ctrl_modes = {
AK8975_REG_CNTL_MODE_POWER_DOWN,
AK8975_REG_CNTL_MODE_ONCE,
AK8975_REG_CNTL_MODE_SELF_TEST,
AK8975_REG_CNTL_MODE_FUSE_ROM},
.data_regs = {
AK8975_REG_HXL,
AK8975_REG_HYL,
AK8975_REG_HZL},
},
{
.type = AK09911,
.raw_to_gauss = ak8963_09911_raw_to_gauss,
.range = 8192,
.ctrl_regs = {
AK09912_REG_ST1,
AK09912_REG_ST2,
AK09912_REG_CNTL2,
AK09912_REG_ASAX,
AK09912_MAX_REGS},
.ctrl_masks = {
AK09912_REG_ST1_DRDY_MASK,
AK09912_REG_ST2_HOFL_MASK,
0,
AK09912_REG_CNTL2_MODE_MASK},
.ctrl_modes = {
AK09912_REG_CNTL_MODE_POWER_DOWN,
AK09912_REG_CNTL_MODE_ONCE,
AK09912_REG_CNTL_MODE_SELF_TEST,
AK09912_REG_CNTL_MODE_FUSE_ROM},
.data_regs = {
AK09912_REG_HXL,
AK09912_REG_HYL,
AK09912_REG_HZL},
},
{
.type = AK09912,
.raw_to_gauss = ak09912_raw_to_gauss,
.range = 32752,
.ctrl_regs = {
AK09912_REG_ST1,
AK09912_REG_ST2,
AK09912_REG_CNTL2,
AK09912_REG_ASAX,
AK09912_MAX_REGS},
.ctrl_masks = {
AK09912_REG_ST1_DRDY_MASK,
AK09912_REG_ST2_HOFL_MASK,
0,
AK09912_REG_CNTL2_MODE_MASK},
.ctrl_modes = {
AK09912_REG_CNTL_MODE_POWER_DOWN,
AK09912_REG_CNTL_MODE_ONCE,
AK09912_REG_CNTL_MODE_SELF_TEST,
AK09912_REG_CNTL_MODE_FUSE_ROM},
.data_regs = {
AK09912_REG_HXL,
AK09912_REG_HYL,
AK09912_REG_HZL},
}
};
/*
* Per-instance context data for the device.
*/
struct ak8975_data {
struct i2c_client *client;
const struct ak_def *def;
struct mutex lock;
u8 asa[3];
long raw_to_gauss[3];
int eoc_gpio;
int eoc_irq;
wait_queue_head_t data_ready_queue;
unsigned long flags;
u8 cntl_cache;
struct iio_mount_matrix orientation;
struct regulator *vdd;
struct regulator *vid;
};
/* Enable attached power regulator if any. */
static int ak8975_power_on(const struct ak8975_data *data)
{
int ret;
ret = regulator_enable(data->vdd);
if (ret) {
dev_warn(&data->client->dev,
"Failed to enable specified Vdd supply\n");
return ret;
}
ret = regulator_enable(data->vid);
if (ret) {
dev_warn(&data->client->dev,
"Failed to enable specified Vid supply\n");
return ret;
}
/*
* According to the datasheet the power supply rise time i 200us
* and the minimum wait time before mode setting is 100us, in
* total 300 us. Add some margin and say minimum 500us here.
*/
usleep_range(500, 1000);
return 0;
}
/* Disable attached power regulator if any. */
static void ak8975_power_off(const struct ak8975_data *data)
{
regulator_disable(data->vid);
regulator_disable(data->vdd);
}
/*
* Return 0 if the i2c device is the one we expect.
* return a negative error number otherwise
*/
static int ak8975_who_i_am(struct i2c_client *client,
enum asahi_compass_chipset type)
{
u8 wia_val[2];
int ret;
/*
* Signature for each device:
* Device | WIA1 | WIA2
* AK09912 | DEVICE_ID | AK09912_DEVICE_ID
* AK09911 | DEVICE_ID | AK09911_DEVICE_ID
* AK8975 | DEVICE_ID | NA
* AK8963 | DEVICE_ID | NA
*/
ret = i2c_smbus_read_i2c_block_data_or_emulated(
client, AK09912_REG_WIA1, 2, wia_val);
if (ret < 0) {
dev_err(&client->dev, "Error reading WIA\n");
return ret;
}
if (wia_val[0] != AK8975_DEVICE_ID)
return -ENODEV;
switch (type) {
case AK8975:
case AK8963:
return 0;
case AK09911:
if (wia_val[1] == AK09911_DEVICE_ID)
return 0;
break;
case AK09912:
if (wia_val[1] == AK09912_DEVICE_ID)
return 0;
break;
default:
dev_err(&client->dev, "Type %d unknown\n", type);
}
return -ENODEV;
}
/*
* Helper function to write to CNTL register.
*/
static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode)
{
u8 regval;
int ret;
regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) |
data->def->ctrl_modes[mode];
ret = i2c_smbus_write_byte_data(data->client,
data->def->ctrl_regs[CNTL], regval);
if (ret < 0) {
return ret;
}
data->cntl_cache = regval;
/* After mode change wait atleast 100us */
usleep_range(100, 500);
return 0;
}
/*
* Handle data ready irq
*/
static irqreturn_t ak8975_irq_handler(int irq, void *data)
{
struct ak8975_data *ak8975 = data;
set_bit(0, &ak8975->flags);
wake_up(&ak8975->data_ready_queue);
return IRQ_HANDLED;
}
/*
* Install data ready interrupt handler
*/
static int ak8975_setup_irq(struct ak8975_data *data)
{
struct i2c_client *client = data->client;
int rc;
int irq;
init_waitqueue_head(&data->data_ready_queue);
clear_bit(0, &data->flags);
if (client->irq)
irq = client->irq;
else
irq = gpio_to_irq(data->eoc_gpio);
rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
dev_name(&client->dev), data);
if (rc < 0) {
dev_err(&client->dev,
"irq %d request failed, (gpio %d): %d\n",
irq, data->eoc_gpio, rc);
return rc;
}
data->eoc_irq = irq;
return rc;
}
/*
* Perform some start-of-day setup, including reading the asa calibration
* values and caching them.
*/
static int ak8975_setup(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct ak8975_data *data = iio_priv(indio_dev);
int ret;
/* Write the fused rom access mode. */
ret = ak8975_set_mode(data, FUSE_ROM);
if (ret < 0) {
dev_err(&client->dev, "Error in setting fuse access mode\n");
return ret;
}
/* Get asa data and store in the device data. */
ret = i2c_smbus_read_i2c_block_data_or_emulated(
client, data->def->ctrl_regs[ASA_BASE],
3, data->asa);
if (ret < 0) {
dev_err(&client->dev, "Not able to read asa data\n");
return ret;
}
/* After reading fuse ROM data set power-down mode */
ret = ak8975_set_mode(data, POWER_DOWN);
if (ret < 0) {
dev_err(&client->dev, "Error in setting power-down mode\n");
return ret;
}
if (data->eoc_gpio > 0 || client->irq > 0) {
ret = ak8975_setup_irq(data);
if (ret < 0) {
dev_err(&client->dev,
"Error setting data ready interrupt\n");
return ret;
}
}
data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]);
data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]);
data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]);
return 0;
}
static int wait_conversion_complete_gpio(struct ak8975_data *data)
{
struct i2c_client *client = data->client;
u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
int ret;
/* Wait for the conversion to complete. */
while (timeout_ms) {
msleep(AK8975_CONVERSION_DONE_POLL_TIME);
if (gpio_get_value(data->eoc_gpio))
break;
timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
}
if (!timeout_ms) {
dev_err(&client->dev, "Conversion timeout happened\n");
return -EINVAL;
}
ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]);
if (ret < 0)
dev_err(&client->dev, "Error in reading ST1\n");
return ret;
}
static int wait_conversion_complete_polled(struct ak8975_data *data)
{
struct i2c_client *client = data->client;
u8 read_status;
u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
int ret;
/* Wait for the conversion to complete. */
while (timeout_ms) {
msleep(AK8975_CONVERSION_DONE_POLL_TIME);
ret = i2c_smbus_read_byte_data(client,
data->def->ctrl_regs[ST1]);
if (ret < 0) {
dev_err(&client->dev, "Error in reading ST1\n");
return ret;
}
read_status = ret;
if (read_status)
break;
timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
}
if (!timeout_ms) {
dev_err(&client->dev, "Conversion timeout happened\n");
return -EINVAL;
}
return read_status;
}
/* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */
static int wait_conversion_complete_interrupt(struct ak8975_data *data)
{
int ret;
ret = wait_event_timeout(data->data_ready_queue,
test_bit(0, &data->flags),
AK8975_DATA_READY_TIMEOUT);
clear_bit(0, &data->flags);
return ret > 0 ? 0 : -ETIME;
}
static int ak8975_start_read_axis(struct ak8975_data *data,
const struct i2c_client *client)
{
/* Set up the device for taking a sample. */
int ret = ak8975_set_mode(data, MODE_ONCE);
if (ret < 0) {
dev_err(&client->dev, "Error in setting operating mode\n");
return ret;
}
/* Wait for the conversion to complete. */
if (data->eoc_irq)
ret = wait_conversion_complete_interrupt(data);
else if (gpio_is_valid(data->eoc_gpio))
ret = wait_conversion_complete_gpio(data);
else
ret = wait_conversion_complete_polled(data);
if (ret < 0)
return ret;
/* This will be executed only for non-interrupt based waiting case */
if (ret & data->def->ctrl_masks[ST1_DRDY]) {
ret = i2c_smbus_read_byte_data(client,
data->def->ctrl_regs[ST2]);
if (ret < 0) {
dev_err(&client->dev, "Error in reading ST2\n");
return ret;
}
if (ret & (data->def->ctrl_masks[ST2_DERR] |
data->def->ctrl_masks[ST2_HOFL])) {
dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
return -EINVAL;
}
}
return 0;
}
/* Retrieve raw flux value for one of the x, y, or z axis. */
static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
{
struct ak8975_data *data = iio_priv(indio_dev);
const struct i2c_client *client = data->client;
const struct ak_def *def = data->def;
__le16 rval;
u16 buff;
int ret;
pm_runtime_get_sync(&data->client->dev);
mutex_lock(&data->lock);
ret = ak8975_start_read_axis(data, client);
if (ret)
goto exit;
ret = i2c_smbus_read_i2c_block_data_or_emulated(
client, def->data_regs[index],
sizeof(rval), (u8*)&rval);
if (ret < 0)
goto exit;
mutex_unlock(&data->lock);
pm_runtime_mark_last_busy(&data->client->dev);
pm_runtime_put_autosuspend(&data->client->dev);
/* Swap bytes and convert to valid range. */
buff = le16_to_cpu(rval);
*val = clamp_t(s16, buff, -def->range, def->range);
return IIO_VAL_INT;
exit:
mutex_unlock(&data->lock);
dev_err(&client->dev, "Error in reading axis\n");
return ret;
}
static int ak8975_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2,
long mask)
{
struct ak8975_data *data = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_RAW:
return ak8975_read_axis(indio_dev, chan->address, val);
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = data->raw_to_gauss[chan->address];
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
static const struct iio_mount_matrix *
ak8975_get_mount_matrix(const struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
return &((struct ak8975_data *)iio_priv(indio_dev))->orientation;
}
static const struct iio_chan_spec_ext_info ak8975_ext_info[] = {
IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix),
{ },
};
#define AK8975_CHANNEL(axis, index) \
{ \
.type = IIO_MAGN, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.address = index, \
.scan_index = index, \
.scan_type = { \
.sign = 's', \
.realbits = 16, \
.storagebits = 16, \
.endianness = IIO_CPU \
}, \
.ext_info = ak8975_ext_info, \
}
static const struct iio_chan_spec ak8975_channels[] = {
AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
static const struct iio_info ak8975_info = {
.read_raw = &ak8975_read_raw,
.driver_module = THIS_MODULE,
};
#ifdef CONFIG_ACPI
static const struct acpi_device_id ak_acpi_match[] = {
{"AK8975", AK8975},
{"AK8963", AK8963},
{"INVN6500", AK8963},
{"AK09911", AK09911},
{"AK09912", AK09912},
{ },
};
MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
#endif
static const char *ak8975_match_acpi_device(struct device *dev,
enum asahi_compass_chipset *chipset)
{
const struct acpi_device_id *id;
id = acpi_match_device(dev->driver->acpi_match_table, dev);
if (!id)
return NULL;
*chipset = (int)id->driver_data;
return dev_name(dev);
}
static void ak8975_fill_buffer(struct iio_dev *indio_dev)
{
struct ak8975_data *data = iio_priv(indio_dev);
const struct i2c_client *client = data->client;
const struct ak_def *def = data->def;
int ret;
s16 buff[8]; /* 3 x 16 bits axis values + 1 aligned 64 bits timestamp */
__le16 fval[3];
mutex_lock(&data->lock);
ret = ak8975_start_read_axis(data, client);
if (ret)
goto unlock;
/*
* For each axis, read the flux value from the appropriate register
* (the register is specified in the iio device attributes).
*/
ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
def->data_regs[0],
3 * sizeof(fval[0]),
(u8 *)fval);
if (ret < 0)
goto unlock;
mutex_unlock(&data->lock);
/* Clamp to valid range. */
buff[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range);
buff[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range);
buff[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range);
iio_push_to_buffers_with_timestamp(indio_dev, buff,
iio_get_time_ns(indio_dev));
return;
unlock:
mutex_unlock(&data->lock);
dev_err(&client->dev, "Error in reading axes block\n");
}
static irqreturn_t ak8975_handle_trigger(int irq, void *p)
{
const struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
ak8975_fill_buffer(indio_dev);
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int ak8975_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ak8975_data *data;
struct iio_dev *indio_dev;
int eoc_gpio;
int err;
const char *name = NULL;
enum asahi_compass_chipset chipset = AK_MAX_TYPE;
const struct ak8975_platform_data *pdata =
dev_get_platdata(&client->dev);
/* Grab and set up the supplied GPIO. */
if (pdata)
eoc_gpio = pdata->eoc_gpio;
else if (client->dev.of_node)
eoc_gpio = of_get_gpio(client->dev.of_node, 0);
else
eoc_gpio = -1;
if (eoc_gpio == -EPROBE_DEFER)
return -EPROBE_DEFER;
/* We may not have a GPIO based IRQ to scan, that is fine, we will
poll if so */
if (gpio_is_valid(eoc_gpio)) {
err = devm_gpio_request_one(&client->dev, eoc_gpio,
GPIOF_IN, "ak_8975");
if (err < 0) {
dev_err(&client->dev,
"failed to request GPIO %d, error %d\n",
eoc_gpio, err);
return err;
}
}
/* Register with IIO */
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (indio_dev == NULL)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
data->eoc_gpio = eoc_gpio;
data->eoc_irq = 0;
if (!pdata) {
err = of_iio_read_mount_matrix(&client->dev,
"mount-matrix",
&data->orientation);
if (err)
return err;
} else
data->orientation = pdata->orientation;
/* id will be NULL when enumerated via ACPI */
if (id) {
chipset = (enum asahi_compass_chipset)(id->driver_data);
name = id->name;
} else if (ACPI_HANDLE(&client->dev)) {
name = ak8975_match_acpi_device(&client->dev, &chipset);
if (!name)
return -ENODEV;
} else
return -ENOSYS;
if (chipset >= AK_MAX_TYPE) {
dev_err(&client->dev, "AKM device type unsupported: %d\n",
chipset);
return -ENODEV;
}
data->def = &ak_def_array[chipset];
/* Fetch the regulators */
data->vdd = devm_regulator_get(&client->dev, "vdd");
if (IS_ERR(data->vdd))
return PTR_ERR(data->vdd);
data->vid = devm_regulator_get(&client->dev, "vid");
if (IS_ERR(data->vid))
return PTR_ERR(data->vid);
err = ak8975_power_on(data);
if (err)
return err;
err = ak8975_who_i_am(client, data->def->type);
if (err < 0) {
dev_err(&client->dev, "Unexpected device\n");
goto power_off;
}
dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
/* Perform some basic start-of-day setup of the device. */
err = ak8975_setup(client);
if (err < 0) {
dev_err(&client->dev, "%s initialization fails\n", name);
goto power_off;
}
mutex_init(&data->lock);
indio_dev->dev.parent = &client->dev;
indio_dev->channels = ak8975_channels;
indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
indio_dev->info = &ak8975_info;
indio_dev->available_scan_masks = ak8975_scan_masks;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->name = name;
err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
NULL);
if (err) {
dev_err(&client->dev, "triggered buffer setup failed\n");
goto power_off;
}
err = iio_device_register(indio_dev);
if (err) {
dev_err(&client->dev, "device register failed\n");
goto cleanup_buffer;
}
/* Enable runtime PM */
pm_runtime_get_noresume(&client->dev);
pm_runtime_set_active(&client->dev);
pm_runtime_enable(&client->dev);
/*
* The device comes online in 500us, so add two orders of magnitude
* of delay before autosuspending: 50 ms.
*/
pm_runtime_set_autosuspend_delay(&client->dev, 50);
pm_runtime_use_autosuspend(&client->dev);
pm_runtime_put(&client->dev);
return 0;
cleanup_buffer:
iio_triggered_buffer_cleanup(indio_dev);
power_off:
ak8975_power_off(data);
return err;
}
static int ak8975_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct ak8975_data *data = iio_priv(indio_dev);
pm_runtime_get_sync(&client->dev);
pm_runtime_put_noidle(&client->dev);
pm_runtime_disable(&client->dev);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
ak8975_set_mode(data, POWER_DOWN);
ak8975_power_off(data);
return 0;
}
#ifdef CONFIG_PM
static int ak8975_runtime_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct ak8975_data *data = iio_priv(indio_dev);
int ret;
/* Set the device in power down if it wasn't already */
ret = ak8975_set_mode(data, POWER_DOWN);
if (ret < 0) {
dev_err(&client->dev, "Error in setting power-down mode\n");
return ret;
}
/* Next cut the regulators */
ak8975_power_off(data);
return 0;
}
static int ak8975_runtime_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct ak8975_data *data = iio_priv(indio_dev);
int ret;
/* Take up the regulators */
ak8975_power_on(data);
/*
* We come up in powered down mode, the reading routines will
* put us in the mode to read values later.
*/
ret = ak8975_set_mode(data, POWER_DOWN);
if (ret < 0) {
dev_err(&client->dev, "Error in setting power-down mode\n");
return ret;
}
return 0;
}
#endif /* CONFIG_PM */
static const struct dev_pm_ops ak8975_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(ak8975_runtime_suspend,
ak8975_runtime_resume, NULL)
};
static const struct i2c_device_id ak8975_id[] = {
{"ak8975", AK8975},
{"ak8963", AK8963},
{"AK8963", AK8963},
{"ak09911", AK09911},
{"ak09912", AK09912},
{}
};
MODULE_DEVICE_TABLE(i2c, ak8975_id);
static const struct of_device_id ak8975_of_match[] = {
{ .compatible = "asahi-kasei,ak8975", },
{ .compatible = "ak8975", },
{ .compatible = "asahi-kasei,ak8963", },
{ .compatible = "ak8963", },
{ .compatible = "asahi-kasei,ak09911", },
{ .compatible = "ak09911", },
{ .compatible = "asahi-kasei,ak09912", },
{ .compatible = "ak09912", },
{}
};
MODULE_DEVICE_TABLE(of, ak8975_of_match);
static struct i2c_driver ak8975_driver = {
.driver = {
.name = "ak8975",
.pm = &ak8975_dev_pm_ops,
.of_match_table = of_match_ptr(ak8975_of_match),
.acpi_match_table = ACPI_PTR(ak_acpi_match),
},
.probe = ak8975_probe,
.remove = ak8975_remove,
.id_table = ak8975_id,
};
module_i2c_driver(ak8975_driver);
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_DESCRIPTION("AK8975 magnetometer driver");
MODULE_LICENSE("GPL");
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