Re: [PATCH 2/3] iio: magn: Add support for BMC150 magnetometer

From: Jonathan Cameron
Date: Wed Apr 22 2015 - 17:07:11 EST

On 22/04/15 13:45, Tirdea, Irina wrote:
>
>
>> -----Original Message-----
>> From: Jonathan Cameron [mailto:jic23@xxxxxxxxxx]
>> Sent: 18 April, 2015 21:07
>> To: Tirdea, Irina; linux-iio@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx
>> Cc: linux-kernel@xxxxxxxxxxxxxxx; Hartmut Knaack; Lars-Peter Clausen; Peter Meerwald; Rob Herring; Pawel Moll; Mark Rutland; Ian
>> Campbell; Kumar Gala
>> Subject: Re: [PATCH 2/3] iio: magn: Add support for BMC150 magnetometer
>>
>> On 17/04/15 11:50, Irina Tirdea wrote:
>>> Add support for the Bosh BMC150 Magnetometer.
>>> The specification can be downloaded from:
>>> http://ae-bst.resource.bosch.com/media/products/dokumente/bmc150/BST-BMC150-DS000-04.pdf.
>>> The chip contains both an accelerometer and a magnetometer.
>>> This patch adds support only for the magnetometer part.
>>>
>>> The temperature compensation formulas are based on bmm050_api.c
>>> authored by contact@xxxxxxxxxxxxxxxxxxxx
>>>
>>> Signed-off-by: Irina Tirdea <irina.tirdea@xxxxxxxxx>
>> Generally looks good, but a few odd bits and pieces...
>
> Thanks for the review, Jonathan!
>
>> Quite a few places you use regmap_update_bits to write with a mask of 0xFF
>> which seems odd..
>>
> The idea there is to not do unnecessary i2c_reads/writes if the value does not change:
> regmap_update_bits will check the cached value and only do the i2c transfer if the value
> did not change.
Odd that regmap_write doesn't check the cache as well, or that we don't have a cleaner
means of doing this but fair enough. Cc'd Mark Brown in case he has any views on this.
>
>> Various other bits inline.
>>> ---
>>> drivers/iio/magnetometer/Kconfig | 14 +
>>> drivers/iio/magnetometer/Makefile | 2 +
>>> drivers/iio/magnetometer/bmc150_magn.c | 1060 ++++++++++++++++++++++++++++++++
>>> 3 files changed, 1076 insertions(+)
>>> create mode 100644 drivers/iio/magnetometer/bmc150_magn.c
>>>
>>> diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig
>>> index a5d6de7..008baca 100644
>>> --- a/drivers/iio/magnetometer/Kconfig
>>> +++ b/drivers/iio/magnetometer/Kconfig
>>> @@ -76,4 +76,18 @@ config IIO_ST_MAGN_SPI_3AXIS
>>> depends on IIO_ST_MAGN_3AXIS
>>> depends on IIO_ST_SENSORS_SPI
>>>
>>> +config BMC150_MAGN
>>> + tristate "Bosch BMC150 Magnetometer Driver"
>>> + depends on I2C
>>> + select IIO_BUFFER
>>> + select IIO_TRIGGERED_BUFFER
>>> + help
>>> + Say yes here to build support for the BMC150 magnetometer.
>>> +
>>> + Currently this only supports the device via an i2c interface.
>>> +
>>> + This is a combo module with both accelerometer and magnetometer.
>>> + This driver is only implementing magnetometer part, which has
>>> + its own address and register map.
>>> +
>>> endmenu
>>> diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile
>>> index 0f5d3c9..e2c3459 100644
>>> --- a/drivers/iio/magnetometer/Makefile
>>> +++ b/drivers/iio/magnetometer/Makefile
>>> @@ -13,3 +13,5 @@ st_magn-$(CONFIG_IIO_BUFFER) += st_magn_buffer.o
>>>
>>> obj-$(CONFIG_IIO_ST_MAGN_I2C_3AXIS) += st_magn_i2c.o
>>> obj-$(CONFIG_IIO_ST_MAGN_SPI_3AXIS) += st_magn_spi.o
>>> +
>>> +obj-$(CONFIG_BMC150_MAGN) += bmc150_magn.o
>>> diff --git a/drivers/iio/magnetometer/bmc150_magn.c b/drivers/iio/magnetometer/bmc150_magn.c
>>> new file mode 100644
>>> index 0000000..e970a0c
>>> --- /dev/null
>>> +++ b/drivers/iio/magnetometer/bmc150_magn.c
>>> @@ -0,0 +1,1060 @@
>>> +/*
>>> + * Bosch BMC150 three-axis magnetic field sensor driver
>>> + *
>>> + * Copyright (c) 2015, Intel Corporation.
>>> + *
>>> + * This code is based on bmm050_api.c authored by contact@xxxxxxxxxxxxxxxxxxx:
>>> + *
>>> + * (C) Copyright 2011~2014 Bosch Sensortec GmbH All Rights Reserved
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify it
>>> + * under the terms and conditions of the GNU General Public License,
>>> + * version 2, as published by the Free Software Foundation.
>>> + *
>>> + * This program is distributed in the hope 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.
>>> + */
>>> +
>>> +#include <linux/module.h>
>>> +#include <linux/i2c.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/acpi.h>
>>> +#include <linux/gpio/consumer.h>
>>> +#include <linux/pm.h>
>>> +#include <linux/pm_runtime.h>
>>> +#include <linux/iio/iio.h>
>>> +#include <linux/iio/sysfs.h>
>>> +#include <linux/iio/buffer.h>
>>> +#include <linux/iio/events.h>
>>> +#include <linux/iio/trigger.h>
>>> +#include <linux/iio/trigger_consumer.h>
>>> +#include <linux/iio/triggered_buffer.h>
>>> +#include <linux/regmap.h>
>>> +
>>> +#define BMC150_MAGN_DRV_NAME "bmc150_magn"
>>> +#define BMC150_MAGN_IRQ_NAME "bmc150_magn_event"
>>> +#define BMC150_MAGN_GPIO_INT "interrupt"
>>> +
>>> +#define BMC150_MAGN_REG_CHIP_ID 0x40
>>> +#define BMC150_MAGN_CHIP_ID_VAL 0x32
>>> +
>>> +#define BMC150_MAGN_REG_X_L 0x42
>>> +#define BMC150_MAGN_REG_X_M 0x43
>>> +#define BMC150_MAGN_REG_Y_L 0x44
>>> +#define BMC150_MAGN_REG_Y_M 0x45
>>> +#define BMC150_MAGN_SHIFT_XY_L 3
>>> +#define BMC150_MAGN_REG_Z_L 0x46
>>> +#define BMC150_MAGN_REG_Z_M 0x47
>>> +#define BMC150_MAGN_SHIFT_Z_L 1
>>> +#define BMC150_MAGN_REG_RHALL_L 0x48
>>> +#define BMC150_MAGN_REG_RHALL_M 0x49
>>> +#define BMC150_MAGN_SHIFT_RHALL_L 2
>>> +
>>> +#define BMC150_MAGN_REG_INT_STATUS 0x4A
>>> +
>>> +#define BMC150_MAGN_REG_POWER 0x4B
>>> +#define BMC150_MAGN_MASK_POWER_CTL BIT(0)
>>> +
>>> +#define BMC150_MAGN_REG_OPMODE_ODR 0x4C
>>> +#define BMC150_MAGN_MASK_OPMODE GENMASK(2, 1)
>>> +#define BMC150_MAGN_SHIFT_OPMODE 1
>>> +#define BMC150_MAGN_MODE_NORMAL 0x00
>>> +#define BMC150_MAGN_MODE_FORCED 0x01
>>> +#define BMC150_MAGN_MODE_SLEEP 0x03
>>> +#define BMC150_MAGN_MASK_ODR GENMASK(5, 3)
>>> +#define BMC150_MAGN_SHIFT_ODR 3
>>> +
>>> +#define BMC150_MAGN_REG_INT 0x4D
>>> +
>>> +#define BMC150_MAGN_REG_INT_DRDY 0x4E
>>> +#define BMC150_MAGN_MASK_DRDY_EN BIT(7)
>>> +#define BMC150_MAGN_SHIFT_DRDY_EN 7
>>> +#define BMC150_MAGN_MASK_DRDY_INT3 BIT(6)
>>> +#define BMC150_MAGN_MASK_DRDY_Z_EN BIT(5)
>>> +#define BMC150_MAGN_MASK_DRDY_Y_EN BIT(4)
>>> +#define BMC150_MAGN_MASK_DRDY_X_EN BIT(3)
>>> +#define BMC150_MAGN_MASK_DRDY_DR_POLARITY BIT(2)
>>> +#define BMC150_MAGN_MASK_DRDY_LATCHING BIT(1)
>>> +#define BMC150_MAGN_MASK_DRDY_INT3_POLARITY BIT(0)
>>> +
>>> +#define BMC150_MAGN_REG_LOW_THRESH 0x4F
>>> +#define BMC150_MAGN_REG_HIGH_THRESH 0x50
>>> +#define BMC150_MAGN_REG_REP_XY 0x51
>>> +#define BMC150_MAGN_REG_REP_Z 0x52
>>> +
>>> +#define BMC150_MAGN_REG_TRIM_START 0x5D
>>> +#define BMC150_MAGN_REG_TRIM_END 0x71
>>> +
>>> +#define BMC150_MAGN_XY_OVERFLOW_VAL -4096
>>> +#define BMC150_MAGN_Z_OVERFLOW_VAL -16384
>>> +
>>> +/* Time from SUSPEND to SLEEP */
>>> +#define BMC150_MAGN_START_UP_TIME_MS 3
>>> +
>>> +#define BMC150_MAGN_AUTO_SUSPEND_DELAY_MS 2000
>>> +
>>> +#define BMC150_MAGN_REGVAL_TO_REPXY(regval) (((regval) * 2) + 1)
>>> +#define BMC150_MAGN_REGVAL_TO_REPZ(regval) ((regval) + 1)
>>> +#define BMC150_MAGN_REPXY_TO_REGVAL(rep) (((rep) - 1) / 2)
>>> +#define BMC150_MAGN_REPZ_TO_REGVAL(rep) ((rep) - 1)
>>> +
>>> +enum bmc150_magn_axis {
>>> + AXIS_X,
>>> + AXIS_Y,
>>> + AXIS_Z,
>>> + RHALL,
>>> + AXIS_XYZ_MAX = RHALL,
>>> + AXIS_XYZR_MAX,
>>> +};
>>> +
>>> +enum bmc150_magn_power_modes {
>>> + BMC150_MAGN_POWER_MODE_SUSPEND,
>>> + BMC150_MAGN_POWER_MODE_SLEEP,
>>> + BMC150_MAGN_POWER_MODE_NORMAL,
>>> +};
>>> +
>>> +struct bmc150_magn_trim_regs {
>>> + s8 x1;
>>> + s8 y1;
>>> + __le16 reserved1;
>>> + u8 reserved2;
>>> + __le16 z4;
>>> + s8 x2;
>>> + s8 y2;
>>> + __le16 reserved3;
>>> + __le16 z2;
>>> + __le16 z1;
>>> + __le16 xyz1;
>>> + __le16 z3;
>>> + s8 xy2;
>>> + u8 xy1;
>>> +} __packed;
>>> +
>>> +struct bmc150_magn_data {
>>> + struct i2c_client *client;
>>> + /*
>>> + * 1. Protect this structure.
>>> + * 2. Serialize sequences that power on/off the device and access HW.
>>> + */
>>> + struct mutex mutex;
>>> + struct regmap *regmap;
>>> + s32 *buffer;
>>> + struct iio_trigger *dready_trig;
>>> + bool dready_trigger_on;
>>> +};
>>> +
>>> +static const struct {
>>> + int freq;
>>> + u8 reg_val;
>>> +} bmc150_magn_samp_freq_table[] = { {10, 0x00},
>>> + {2, 0x01},
>>> + {6, 0x02},
>>> + {8, 0x03},
>>> + {15, 0x04},
>>> + {20, 0x05},
>>> + {25, 0x06},
>>> + {30, 0x07} };
>>> +
>>> +enum bmc150_magn_presets {
>>> + LOW_POWER_PRESET,
>>> + REGULAR_PRESET,
>>> + ENHANCED_REGULAR_PRESET,
>>> + HIGH_ACCURACY_PRESET
>>> +};
>>> +
>>> +static const struct bmc150_magn_preset {
>>> + u8 rep_xy;
>>> + u8 rep_z;
>>> + u8 odr;
>>> +} bmc150_magn_presets_table[] = {
>>> + [LOW_POWER_PRESET] = {3, 3, 10},
>>> + [REGULAR_PRESET] = {9, 15, 10},
>>> + [ENHANCED_REGULAR_PRESET] = {15, 27, 10},
>>> + [HIGH_ACCURACY_PRESET] = {47, 83, 20},
>>> +};
>>> +
>>> +#define BMC150_MAGN_DEFAULT_PRESET REGULAR_PRESET
>>> +
>>> +static bool bmc150_magn_is_writeable_reg(struct device *dev, unsigned int reg)
>>> +{
>>> + switch (reg) {
>>> + case BMC150_MAGN_REG_POWER:
>>> + case BMC150_MAGN_REG_OPMODE_ODR:
>>> + case BMC150_MAGN_REG_INT:
>>> + case BMC150_MAGN_REG_INT_DRDY:
>>> + case BMC150_MAGN_REG_LOW_THRESH:
>>> + case BMC150_MAGN_REG_HIGH_THRESH:
>>> + case BMC150_MAGN_REG_REP_XY:
>>> + case BMC150_MAGN_REG_REP_Z:
>>> + return true;
>>> + default:
>>> + return false;
>>> + };
>>> +}
>>> +
>>> +static bool bmc150_magn_is_volatile_reg(struct device *dev, unsigned int reg)
>>> +{
>>> + switch (reg) {
>>> + case BMC150_MAGN_REG_X_L:
>>> + case BMC150_MAGN_REG_X_M:
>>> + case BMC150_MAGN_REG_Y_L:
>>> + case BMC150_MAGN_REG_Y_M:
>>> + case BMC150_MAGN_REG_Z_L:
>>> + case BMC150_MAGN_REG_Z_M:
>>> + case BMC150_MAGN_REG_RHALL_L:
>>> + case BMC150_MAGN_REG_RHALL_M:
>>> + case BMC150_MAGN_REG_INT_STATUS:
>>> + return true;
>>> + default:
>>> + return false;
>>> + }
>>> +}
>>> +
>>> +static const struct regmap_config bmc150_magn_regmap_config = {
>>> + .reg_bits = 8,
>>> + .val_bits = 8,
>>> +
>>> + .max_register = BMC150_MAGN_REG_TRIM_END,
>>> + .cache_type = REGCACHE_RBTREE,
>>> +
>>> + .writeable_reg = bmc150_magn_is_writeable_reg,
>>> + .volatile_reg = bmc150_magn_is_volatile_reg,
>>> +};
>>> +
>> Why bother with this? It's only called in one place and then with a constant so you'll
>> always get the top option.
>
> Indeed. I thought I will have multiple usages, but now it does not make sense anymore.
> I will remove it and use usleep_range instead.
>
>>> +static void bmc150_magn_sleep(int sleep_time_ms)
>>> +{
>>> + if (sleep_time_ms < 20)
>>> + usleep_range(sleep_time_ms * 1000, 20000);
>>> + else
>>> + msleep_interruptible(sleep_time_ms);
>>> +}
>>> +
>>> +static int bmc150_magn_set_power_mode(struct bmc150_magn_data *data,
>>> + enum bmc150_magn_power_modes mode,
>>> + bool state)
>>> +{
>>> + int ret;
>>> +
>>> + switch (mode) {
>>> + case BMC150_MAGN_POWER_MODE_SUSPEND:
>>> + ret = regmap_update_bits(data->regmap, BMC150_MAGN_REG_POWER,
>>> + BMC150_MAGN_MASK_POWER_CTL, !state);
>>> + if (ret < 0)
>>> + return ret;
>>> + bmc150_magn_sleep(BMC150_MAGN_START_UP_TIME_MS);
>>> + return 0;
>>> + case BMC150_MAGN_POWER_MODE_SLEEP:
>>> + return regmap_update_bits(data->regmap,
>>> + BMC150_MAGN_REG_OPMODE_ODR,
>>> + BMC150_MAGN_MASK_OPMODE,
>>> + BMC150_MAGN_MODE_SLEEP <<
>>> + BMC150_MAGN_SHIFT_OPMODE);
>>> + case BMC150_MAGN_POWER_MODE_NORMAL:
>>> + return regmap_update_bits(data->regmap,
>>> + BMC150_MAGN_REG_OPMODE_ODR,
>>> + BMC150_MAGN_MASK_OPMODE,
>>> + BMC150_MAGN_MODE_NORMAL <<
>>> + BMC150_MAGN_SHIFT_OPMODE);
>>> + }
>>> +
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static int bmc150_magn_set_power_state(struct bmc150_magn_data *data, bool on)
>>> +{
>>> +#ifdef CONFIG_PM
>>> + int ret;
>>> +
>>> + if (on) {
>>> + ret = pm_runtime_get_sync(&data->client->dev);
>>> + } else {
>>> + pm_runtime_mark_last_busy(&data->client->dev);
>>> + ret = pm_runtime_put_autosuspend(&data->client->dev);
>>> + }
>>> +
>>> + if (ret < 0) {
>>> + dev_err(&data->client->dev,
>>> + "failed to change power state to %d\n", on);
>>> + if (on)
>>> + pm_runtime_put_noidle(&data->client->dev);
>>> +
>>> + return ret;
>>> + }
>>> +#endif
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int bmc150_magn_get_odr(struct bmc150_magn_data *data, int *val)
>>> +{
>>> + int ret, reg_val;
>>> + u8 i, odr_val;
>>> +
>>> + ret = regmap_read(data->regmap, BMC150_MAGN_REG_OPMODE_ODR, &reg_val);
>>> + if (ret < 0)
>>> + return ret;
>>> + odr_val = (reg_val & BMC150_MAGN_MASK_ODR) >> BMC150_MAGN_SHIFT_ODR;
>>> +
>>> + for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++)
>>> + if (bmc150_magn_samp_freq_table[i].reg_val == odr_val) {
>>> + *val = bmc150_magn_samp_freq_table[i].freq;
>>> + return 0;
>>> + }
>>> +
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static int bmc150_magn_set_odr(struct bmc150_magn_data *data, int val)
>>> +{
>>> + int ret;
>>> + u8 i;
>>> +
>>> + for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++) {
>>> + if (bmc150_magn_samp_freq_table[i].freq == val) {
>>> + ret = regmap_update_bits(data->regmap,
>>> + BMC150_MAGN_REG_OPMODE_ODR,
>>> + BMC150_MAGN_MASK_ODR,
>>> + bmc150_magn_samp_freq_table[i].
>>> + reg_val <<
>>> + BMC150_MAGN_SHIFT_ODR);
>>> + if (ret < 0)
>>> + return ret;
>>> + return 0;
>>> + }
>>> + }
>>> +
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static s32 bmc150_magn_compensate_x(struct bmc150_magn_trim_regs *tregs, s16 x,
>>> + u16 rhall)
>>> +{
>>> + s16 val;
>>> + u16 xyz1 = le16_to_cpu(tregs->xyz1);
>>> +
>>> + if (x == BMC150_MAGN_XY_OVERFLOW_VAL)
>>> + return S32_MIN;
>>> +
>>> + if (!rhall)
>>> + rhall = xyz1;
>>> +
>>> + val = ((s16)(((u16)((((s32)xyz1) << 14) / rhall)) - ((u16)0x4000)));
>>> + val = ((s16)((((s32)x) * ((((((((s32)tregs->xy2) * ((((s32)val) *
>>> + ((s32)val)) >> 7)) + (((s32)val) *
>>> + ((s32)(((s16)tregs->xy1) << 7)))) >> 9) + ((s32)0x100000)) *
>>> + ((s32)(((s16)tregs->x2) + ((s16)0xA0)))) >> 12)) >> 13)) +
>>> + (((s16)tregs->x1) << 3);
>>> +
>>> + return (s32)val;
>>> +}
>>> +
>>> +static s32 bmc150_magn_compensate_y(struct bmc150_magn_trim_regs *tregs, s16 y,
>>> + u16 rhall)
>>> +{
>>> + s16 val;
>>> + u16 xyz1 = le16_to_cpu(tregs->xyz1);
>>> +
>>> + if (y == BMC150_MAGN_XY_OVERFLOW_VAL)
>>> + return S32_MIN;
>>> +
>>> + if (!rhall)
>>> + rhall = xyz1;
>>> +
>>> + val = ((s16)(((u16)((((s32)xyz1) << 14) / rhall)) - ((u16)0x4000)));
>>> + val = ((s16)((((s32)y) * ((((((((s32)tregs->xy2) * ((((s32)val) *
>>> + ((s32)val)) >> 7)) + (((s32)val) *
>>> + ((s32)(((s16)tregs->xy1) << 7)))) >> 9) + ((s32)0x100000)) *
>>> + ((s32)(((s16)tregs->y2) + ((s16)0xA0)))) >> 12)) >> 13)) +
>>> + (((s16)tregs->y1) << 3);
>>> +
>>> + return (s32)val;
>>> +}
>>> +
>>> +static s32 bmc150_magn_compensate_z(struct bmc150_magn_trim_regs *tregs, s16 z,
>>> + u16 rhall)
>>> +{
>>> + s32 val;
>>> + u16 xyz1 = le16_to_cpu(tregs->xyz1);
>>> + u16 z1 = le16_to_cpu(tregs->z1);
>>> + s16 z2 = le16_to_cpu(tregs->z2);
>>> + s16 z3 = le16_to_cpu(tregs->z3);
>>> + s16 z4 = le16_to_cpu(tregs->z4);
>>> +
>>> + if (z == BMC150_MAGN_Z_OVERFLOW_VAL)
>>> + return S32_MIN;
>>> +
>>> + val = (((((s32)(z - z4)) << 15) - ((((s32)z3) * ((s32)(((s16)rhall) -
>>> + ((s16)xyz1)))) >> 2)) / (z2 + ((s16)(((((s32)z1) *
>>> + ((((s16)rhall) << 1))) + (1 << 15)) >> 16))));
>>> +
>>> + return val;
>>> +}
>>> +
>>> +static int bmc150_magn_read_xyz(struct bmc150_magn_data *data, s32 *buffer)
>>> +{
>>> + int ret;
>>> + __le16 values[AXIS_XYZR_MAX];
>>> + s16 raw_x, raw_y, raw_z;
>>> + u16 rhall;
>>> + struct bmc150_magn_trim_regs tregs;
>>> +
>>> + ret = regmap_bulk_read(data->regmap, BMC150_MAGN_REG_X_L,
>>> + values, sizeof(values));
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + raw_x = (s16)le16_to_cpu(values[AXIS_X]) >> BMC150_MAGN_SHIFT_XY_L;
>>> + raw_y = (s16)le16_to_cpu(values[AXIS_Y]) >> BMC150_MAGN_SHIFT_XY_L;
>>> + raw_z = (s16)le16_to_cpu(values[AXIS_Z]) >> BMC150_MAGN_SHIFT_Z_L;
>>> + rhall = le16_to_cpu(values[RHALL]) >> BMC150_MAGN_SHIFT_RHALL_L;
>>> +
>>> + ret = regmap_bulk_read(data->regmap, BMC150_MAGN_REG_TRIM_START,
>>> + &tregs, sizeof(tregs));
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + buffer[AXIS_X] = bmc150_magn_compensate_x(&tregs, raw_x, rhall);
>>> + buffer[AXIS_Y] = bmc150_magn_compensate_y(&tregs, raw_y, rhall);
>>> + buffer[AXIS_Z] = bmc150_magn_compensate_z(&tregs, raw_z, rhall);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int bmc150_magn_read_raw(struct iio_dev *indio_dev,
>>> + struct iio_chan_spec const *chan,
>>> + int *val, int *val2, long mask)
>>> +{
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> + int ret, tmp;
>>> + s32 values[AXIS_XYZ_MAX];
>>> +
>>> + switch (mask) {
>>> + case IIO_CHAN_INFO_RAW:
>>> + if (iio_buffer_enabled(indio_dev))
>>> + return -EBUSY;
>>> + mutex_lock(&data->mutex);
>>> +
>>> + ret = bmc150_magn_set_power_state(data, true);
>>> + if (ret < 0)
>> You just returned with the mutex held... Check the other places this might happen please.
> Oops... Seems I missed the unlock twice in this function. Thanks for catching this!
>
>>> + return ret;
>>> +
>>> + ret = bmc150_magn_read_xyz(data, values);
>>> + if (ret < 0) {
>>> + bmc150_magn_set_power_state(data, false);
>>> + mutex_unlock(&data->mutex);
>>> + return ret;
>>> + }
>>> + *val = values[chan->scan_index];
>>> +
>>> + ret = bmc150_magn_set_power_state(data, false);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + mutex_unlock(&data->mutex);
>>> + return IIO_VAL_INT;
>>> + case IIO_CHAN_INFO_SCALE:
>>> + /*
>>> + * The API/driver performs an off-chip temperature
>>> + * compensation and outputs x/y/z magnetic field data in
>>> + * 16 LSB/uT to the upper application layer.
>>> + */
>>> + *val = 0;
>>> + *val2 = 625;
>>> + return IIO_VAL_INT_PLUS_MICRO;
>>> + case IIO_CHAN_INFO_SAMP_FREQ:
>>> + ret = bmc150_magn_get_odr(data, val);
>>> + if (ret < 0)
>>> + return ret;
>>> + return IIO_VAL_INT;
>>> + case IIO_CHAN_INFO_CALIBREPETITIONS:
>>> + switch (chan->channel2) {
>>> + case IIO_MOD_X:
>>> + case IIO_MOD_Y:
>>> + ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_XY,
>>> + &tmp);
>>> + if (ret < 0)
>>> + return ret;
>>> + *val = BMC150_MAGN_REGVAL_TO_REPXY(tmp);
>>> + return IIO_VAL_INT;
>>> + case IIO_MOD_Z:
>>> + ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_Z,
>>> + &tmp);
>>> + if (ret < 0)
>>> + return ret;
>>> + *val = BMC150_MAGN_REGVAL_TO_REPZ(tmp);
>>> + return IIO_VAL_INT;
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +}
>>> +
>>> +static int bmc150_magn_write_raw(struct iio_dev *indio_dev,
>>> + struct iio_chan_spec const *chan,
>>> + int val, int val2, long mask)
>>> +{
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + switch (mask) {
>>> + case IIO_CHAN_INFO_SAMP_FREQ:
>>> + mutex_lock(&data->mutex);
>>> + ret = bmc150_magn_set_odr(data, val);
>>> + mutex_unlock(&data->mutex);
>>> + return ret;
>>> + case IIO_CHAN_INFO_CALIBREPETITIONS:
>>> + switch (chan->channel2) {
>>> + case IIO_MOD_X:
>>> + case IIO_MOD_Y:
>>> + if (val < 1 || val > 511)
>>> + return -EINVAL;
>>> + return regmap_update_bits(data->regmap,
>>> + BMC150_MAGN_REG_REP_XY,
>>> + 0xFF,
>>> + BMC150_MAGN_REPXY_TO_REGVAL
>>> + (val));
>>> + case IIO_MOD_Z:
>>> + if (val < 1 || val > 256)
>>> + return -EINVAL;
>>> + return regmap_update_bits(data->regmap,
>>> + BMC150_MAGN_REG_REP_Z,
>>> + 0xFF,
>>> + BMC150_MAGN_REPZ_TO_REGVAL
>>> + (val));
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +}
>>> +
>>> +static int bmc150_magn_validate_trigger(struct iio_dev *indio_dev,
>>> + struct iio_trigger *trig)
>>> +{
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> +
>>> + if (data->dready_trig != trig)
>>> + return -EINVAL;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int bmc150_magn_update_scan_mode(struct iio_dev *indio_dev,
>>> + const unsigned long *scan_mask)
>>> +{
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> +
>>> + mutex_lock(&data->mutex);
>>> + kfree(data->buffer);
>>> + data->buffer = kzalloc(indio_dev->scan_bytes, GFP_KERNEL);
>> Call be cynical, but how large can this buffer get?
>>
>> I'd just allocate it as part of data in the first place then you
>> can drop this function entirely and don't have to clean it up
>> separately.
> With all channels enabled it is 24 bytes. I'll allocate it with data.
>
>>> + mutex_unlock(&data->mutex);
>>> +
>>> + if (!data->buffer)
>>> + return -ENOMEM;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("2 6 8 10 15 20 25 30");
>>> +
>>> +static struct attribute *bmc150_magn_attributes[] = {
>>> + &iio_const_attr_sampling_frequency_available.dev_attr.attr,
>>> + NULL,
>>> +};
>>> +
>>> +static const struct attribute_group bmc150_magn_attrs_group = {
>>> + .attrs = bmc150_magn_attributes,
>>> +};
>>> +
>>> +#define BMC150_MAGN_CHANNEL(_axis) { \
>>> + .type = IIO_MAGN, \
>>> + .modified = 1, \
>>> + .channel2 = IIO_MOD_##_axis, \
>>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
>>> + BIT(IIO_CHAN_INFO_CALIBREPETITIONS), \
>>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
>>> + BIT(IIO_CHAN_INFO_SCALE), \
>>> + .scan_index = AXIS_##_axis, \
>>> + .scan_type = { \
>>> + .sign = 's', \
>>> + .realbits = 32, \
>>> + .storagebits = 32, \
>>> + .shift = 0, \
>>> + .endianness = IIO_LE \
>>> + }, \
>>> +}
>>> +
>>> +static const struct iio_chan_spec bmc150_magn_channels[] = {
>>> + BMC150_MAGN_CHANNEL(X),
>>> + BMC150_MAGN_CHANNEL(Y),
>>> + BMC150_MAGN_CHANNEL(Z),
>>> + IIO_CHAN_SOFT_TIMESTAMP(3),
>>> +};
>>> +
>>> +static const struct iio_info bmc150_magn_info = {
>>> + .attrs = &bmc150_magn_attrs_group,
>>> + .read_raw = bmc150_magn_read_raw,
>>> + .write_raw = bmc150_magn_write_raw,
>>> + .validate_trigger = bmc150_magn_validate_trigger,
>>> + .update_scan_mode = bmc150_magn_update_scan_mode,
>>> + .driver_module = THIS_MODULE,
>>> +};
>>> +
>>> +static const unsigned long bmc150_magn_scan_masks[] = {0x07, 0};
>>> +
>>> +static irqreturn_t bmc150_magn_trigger_handler(int irq, void *p)
>>> +{
>>> + struct iio_poll_func *pf = p;
>>> + struct iio_dev *indio_dev = pf->indio_dev;
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + mutex_lock(&data->mutex);
>>> + ret = bmc150_magn_read_xyz(data, data->buffer);
>>> + mutex_unlock(&data->mutex);
>>> + if (ret < 0)
>>> + goto err;
>>> +
>>> + iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
>>> + pf->timestamp);
>>> +
>>> +err:
>>> + iio_trigger_notify_done(data->dready_trig);
>>> +
>>> + return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int bmc150_magn_init(struct bmc150_magn_data *data)
>>> +{
>>> + int ret, chip_id;
>>> + struct bmc150_magn_preset preset;
>>> + struct bmc150_magn_trim_regs tregs;
>>> +
>>> + ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND,
>>> + false);
>>> + if (ret < 0) {
>>> + dev_err(&data->client->dev,
>>> + "Failed to bring up device from suspend mode\n");
>>> + return ret;
>>> + }
>>> +
>>> + ret = regmap_read(data->regmap, BMC150_MAGN_REG_CHIP_ID, &chip_id);
>>> + if (ret < 0) {
>>> + dev_err(&data->client->dev, "Failed reading chip id\n");
>>> + goto err_poweroff;
>>> + }
>>> + if (chip_id != BMC150_MAGN_CHIP_ID_VAL) {
>>> + dev_err(&data->client->dev, "Invalid chip id 0x%x\n", ret);
>>> + ret = -ENODEV;
>>> + goto err_poweroff;
>>> + }
>>> + dev_dbg(&data->client->dev, "Chip id %x\n", ret);
>>> +
>>> + preset = bmc150_magn_presets_table[BMC150_MAGN_DEFAULT_PRESET];
>>> + ret = bmc150_magn_set_odr(data, preset.odr);
>>> + if (ret < 0) {
>>> + dev_err(&data->client->dev, "Failed to set ODR to %d\n",
>>> + preset.odr);
>>> + goto err_poweroff;
>>> + }
>>> +
>>> + ret = regmap_update_bits(data->regmap,
>>> + BMC150_MAGN_REG_REP_XY,
>>> + 0xFF,
>>> + BMC150_MAGN_REPXY_TO_REGVAL(preset.rep_xy));
>>> + if (ret < 0) {
>>> + dev_err(&data->client->dev, "Failed to set REP XY to %d\n",
>>> + preset.rep_xy);
>>> + goto err_poweroff;
>>> + }
>>> +
>>> + ret = regmap_update_bits(data->regmap,
>>> + BMC150_MAGN_REG_REP_Z,
>>> + 0xFF,
>> Umm. With a mask of 0xFF are we not just setting the whole register? In which
>> case why use update_bits? regmap_write instead...
>
> I am using regmap_update_bits because it also checks if the value actually changed.
> I could use regmap_write here instead, since we are initializing the driver, but
> I would keep regmap_update_bits where the value is updated by the user (so we don't
> do the i2c transfer if the value did not change).
>
>>> + BMC150_MAGN_REPZ_TO_REGVAL(preset.rep_z));
>>> + if (ret < 0) {
>>> + dev_err(&data->client->dev, "Failed to set REP Z to %d\n",
>>> + preset.rep_z);
>>> + goto err_poweroff;
>>> + }
>>> +
>>> + /* Cache trim registers in regmap. */
>> A little ugly. Is there no way of asking regmap to fill it's cache for certain registers?
>> Actually as I read it having taken a quick look, regcache_hw_init will read all your registers
>> given you haven't provided defaults. Hence this will be cached already..
> Unfortunately it does not work in this case.
> In the current implementation the registers are not cached because num_reg_defaults_raw is not set.
> After setting num_reg_defaults_raw, regcache_hw_init will read all registers starting from register
> 0, but bmc150 magn starts its register map at register 0x40. I am not sure yet how to force a different
> stat register value or how to cache the registers in another way.
>
> I will remove the regmap_bulk_read for now, so the actual transfer will be done when the first interrupt
> is handled. I will look further into this and come with a follow-up patch when I find a better solution.
Mark - any suggestions?
>
>>> + ret = regmap_bulk_read(data->regmap, BMC150_MAGN_REG_TRIM_START,
>>> + &tregs, sizeof(tregs));
>>> + if (ret < 0) {
>>> + dev_err(&data->client->dev, "Failed to read trim registers\n");
>>> + goto err_poweroff;
>>> + }
>>> +
>>> + ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
>>> + true);
>>> + if (ret < 0) {
>>> + dev_err(&data->client->dev, "Failed to power on device\n");
>>> + goto err_poweroff;
>>> + }
>>> +
>>> + return 0;
>>> +
>>> +err_poweroff:
>>> + bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
>>> + return ret;
>>> +}
>>> +
>>> +static int bmc150_magn_reset_intr(struct bmc150_magn_data *data)
>>> +{
>>> + int tmp;
>>> +
>>> + /*
>>> + * Data Ready (DRDY) is always cleared after
>>> + * readout of data registers ends.
>>> + */
>>> + return regmap_read(data->regmap, BMC150_MAGN_REG_X_L, &tmp);
>> Good to see this here. Often people don't bother on the basis
>> of course the driver has already read the data register!
>> (which it might not have done if the trigger is being used by another
>> device).
>>> +}
>>> +
>>> +static int bmc150_magn_trig_try_reen(struct iio_trigger *trig)
>>> +{
>>> + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + if (!data->dready_trigger_on)
>>> + return 0;
>>> +
>>> + mutex_lock(&data->mutex);
>>> + ret = bmc150_magn_reset_intr(data);
>>> + mutex_unlock(&data->mutex);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int bmc150_magn_data_rdy_trigger_set_state(struct iio_trigger *trig,
>>> + bool state)
>>> +{
>>> + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> + int ret = 0;
>>> +
>>> + mutex_lock(&data->mutex);
>>> + if (state == data->dready_trigger_on)
>>> + goto err_unlock;
>>> +
>>> + ret = bmc150_magn_set_power_state(data, state);
>>> + if (ret < 0)
>>> + goto err_unlock;
>>> +
>>> + ret = regmap_update_bits(data->regmap, BMC150_MAGN_REG_INT_DRDY,
>>> + BMC150_MAGN_MASK_DRDY_EN,
>>> + state << BMC150_MAGN_SHIFT_DRDY_EN);
>>> + if (ret < 0)
>>> + goto err_poweroff;
>>> +
>>> + data->dready_trigger_on = state;
>>> +
>>> + if (state) {
>>> + ret = bmc150_magn_reset_intr(data);
>>> + if (ret < 0)
>>> + goto err_poweroff;
>>> + }
>>> + mutex_unlock(&data->mutex);
>>> +
>>> + return 0;
>>> +
>>> +err_poweroff:
>>> + bmc150_magn_set_power_state(data, false);
>>> +err_unlock:
>>> + mutex_unlock(&data->mutex);
>>> + return ret;
>>> +}
>>> +
>>> +static const struct iio_trigger_ops bmc150_magn_trigger_ops = {
>>> + .set_trigger_state = bmc150_magn_data_rdy_trigger_set_state,
>>> + .try_reenable = bmc150_magn_trig_try_reen,
>>> + .owner = THIS_MODULE,
>>> +};
>>> +
>>> +static int bmc150_magn_gpio_probe(struct i2c_client *client)
>>> +{
>>> + struct device *dev;
>>> + struct gpio_desc *gpio;
>>> + int ret;
>>> +
>>> + if (!client)
>>> + return -EINVAL;
>>> +
>>> + dev = &client->dev;
>>> +
>>> + /* data ready GPIO interrupt pin */
>>> + gpio = devm_gpiod_get_index(dev, BMC150_MAGN_GPIO_INT, 0);
>>> + if (IS_ERR(gpio)) {
>>> + dev_err(dev, "ACPI GPIO get index failed\n");
>>> + return PTR_ERR(gpio);
>>> + }
>>> +
>>> + ret = gpiod_direction_input(gpio);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + ret = gpiod_to_irq(gpio);
>>> +
>>> + dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static const char *bmc150_magn_match_acpi_device(struct device *dev)
>>> +{
>>> + const struct acpi_device_id *id;
>>> +
>>> + id = acpi_match_device(dev->driver->acpi_match_table, dev);
>>> + if (!id)
>>> + return NULL;
>>> +
>>> + return dev_name(dev);
>>> +}
>>> +
>>> +static int bmc150_magn_probe(struct i2c_client *client,
>>> + const struct i2c_device_id *id)
>>> +{
>>> + struct bmc150_magn_data *data;
>>> + struct iio_dev *indio_dev;
>>> + const char *name = NULL;
>>> + 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;
>>> +
>>> + if (id)
>>> + name = id->name;
>>> + else if (ACPI_HANDLE(&client->dev))
>>> + name = bmc150_magn_match_acpi_device(&client->dev);
>>> + else
>>> + return -ENOSYS;
>>> +
>>> + mutex_init(&data->mutex);
>>> + data->regmap = devm_regmap_init_i2c(client, &bmc150_magn_regmap_config);
>>> + if (IS_ERR(data->regmap)) {
>>> + dev_err(&client->dev, "Failed to allocate register map\n");
>>> + return PTR_ERR(data->regmap);
>>> + }
>>> +
>>> + ret = bmc150_magn_init(data);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + indio_dev->dev.parent = &client->dev;
>>> + indio_dev->channels = bmc150_magn_channels;
>>> + indio_dev->num_channels = ARRAY_SIZE(bmc150_magn_channels);
>>> + indio_dev->available_scan_masks = bmc150_magn_scan_masks;
>>> + indio_dev->name = name;
>>> + indio_dev->modes = INDIO_DIRECT_MODE;
>>> + indio_dev->info = &bmc150_magn_info;
>>> +
>>> + if (client->irq <= 0)
>>> + client->irq = bmc150_magn_gpio_probe(client);
>>> +
>>> + if (client->irq > 0) {
>>> + data->dready_trig = devm_iio_trigger_alloc(&client->dev,
>>> + "%s-dev%d",
>>> + indio_dev->name,
>>> + indio_dev->id);
>>> + if (!data->dready_trig) {
>>> + ret = -ENOMEM;
>>> + dev_err(&client->dev, "iio trigger alloc failed\n");
>>> + goto err_poweroff;
>>> + }
>>> +
>>> + data->dready_trig->dev.parent = &client->dev;
>>> + data->dready_trig->ops = &bmc150_magn_trigger_ops;
>>> + iio_trigger_set_drvdata(data->dready_trig, indio_dev);
>>> + ret = iio_trigger_register(data->dready_trig);
>>> + if (ret) {
>>> + dev_err(&client->dev, "iio trigger register failed\n");
>>> + goto err_poweroff;
>>> + }
>>> +
>>> + ret = iio_triggered_buffer_setup(indio_dev,
>>> + &iio_pollfunc_store_time,
>>> + bmc150_magn_trigger_handler,
>>> + NULL);
>>> + if (ret < 0) {
>>> + dev_err(&client->dev,
>>> + "iio triggered buffer setup failed\n");
>>> + goto err_trigger_unregister;
>>> + }
>>> +
>>> + ret = devm_request_threaded_irq(&client->dev, client->irq,
>>> + iio_trigger_generic_data_rdy_poll,
>>> + NULL,
>>> + IRQF_TRIGGER_RISING | IRQF_ONESHOT,
>>> + BMC150_MAGN_IRQ_NAME,
>>> + data->dready_trig);
>>> + if (ret < 0) {
>>> + dev_err(&client->dev, "request irq %d failed\n",
>>> + client->irq);
>>> + goto err_buffer_cleanup;
>>> + }
>>> + }
>>> +
>>> + ret = iio_device_register(indio_dev);
>>> + if (ret < 0) {
>>> + dev_err(&client->dev, "unable to register iio device\n");
>>> + goto err_buffer_cleanup;
>>> + }
>>> +
>>> + ret = pm_runtime_set_active(&client->dev);
>>> + if (ret)
>>> + goto err_iio_unregister;
>>> +
>>> + pm_runtime_enable(&client->dev);
>>> + pm_runtime_set_autosuspend_delay(&client->dev,
>>> + BMC150_MAGN_AUTO_SUSPEND_DELAY_MS);
>>> + pm_runtime_use_autosuspend(&client->dev);
>>> +
>>> + dev_dbg(&indio_dev->dev, "Registered device %s\n", name);
>>> +
>>> + return 0;
>>> +
>>> +err_iio_unregister:
>>> + iio_device_unregister(indio_dev);
>>> +err_buffer_cleanup:
>>
>> Hmm. There is an issue with this being obviously correct.
>> The unwind ordering different from setup.
>> Because you have devm_request_threaded_irq calls they will unwind only after these
>> calls, but should occur before.
>> Now it probaby makes no difference, but it does fail the obviously correct test.
>>
>> It's also the case in the remove. I'd be inclined not to use the devm versin
>> of the irq request, but do it explicitly. This one comes up a lot and much like
>> the devm_iio_register_device call it's only really a good idea if everything
>> is managed. In mixed cases, I'd avoid it.
>>
> I agree. I will use request_threaded_irq instead.
>
>> Maybe I'm just being overly fussy...
>>
>>> + if (data->dready_trig)
>>> + iio_triggered_buffer_cleanup(indio_dev);
>>> +err_trigger_unregister:
>>> + if (data->dready_trig)
>>> + iio_trigger_unregister(data->dready_trig);
>>> +err_poweroff:
>>> + bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
>>> + return ret;
>>> +}
>>> +
>>> +static int bmc150_magn_remove(struct i2c_client *client)
>>> +{
>>> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> +
>>> + pm_runtime_disable(&client->dev);
>>> + pm_runtime_set_suspended(&client->dev);
>>> + pm_runtime_put_noidle(&client->dev);
>>> +
>>> + iio_device_unregister(indio_dev);
>>> +
>>> + if (data->dready_trig) {
>>> + iio_triggered_buffer_cleanup(indio_dev);
>>> + iio_trigger_unregister(data->dready_trig);
>>> + }
>> As mentioned above, this clean up isn't needed if you simply
>> always make data->buffer the largest size it can ever be.
> Yes, I will remove this after allocating the data->buffer with data.
>>> + kfree(data->buffer);
>>> +
>>> + mutex_lock(&data->mutex);
>>> + bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
>>> + mutex_unlock(&data->mutex);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +#ifdef CONFIG_PM
>>> +static int bmc150_magn_runtime_suspend(struct device *dev)
>>> +{
>>> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + mutex_lock(&data->mutex);
>>> + ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
>>> + true);
>>> + mutex_unlock(&data->mutex);
>>> + if (ret < 0) {
>>> + dev_err(&data->client->dev, "powering off device failed\n");
>>> + return -EAGAIN;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int bmc150_magn_runtime_resume(struct device *dev)
>>> +{
>>> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> +
>>> + return bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
>>> + true);
>>> +}
>>> +#endif
>>> +
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int bmc150_magn_suspend(struct device *dev)
>>> +{
>>> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + mutex_lock(&data->mutex);
>>> + ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
>>> + true);
>>> + mutex_unlock(&data->mutex);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int bmc150_magn_resume(struct device *dev)
>>> +{
>>> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>>> + struct bmc150_magn_data *data = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + mutex_lock(&data->mutex);
>>> + ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
>>> + true);
>>> + mutex_unlock(&data->mutex);
>>> +
>>> + return ret;
>>> +}
>>> +#endif
>>> +
>>> +static const struct dev_pm_ops bmc150_magn_pm_ops = {
>>> + SET_SYSTEM_SLEEP_PM_OPS(bmc150_magn_suspend, bmc150_magn_resume)
>>> + SET_RUNTIME_PM_OPS(bmc150_magn_runtime_suspend,
>>> + bmc150_magn_runtime_resume, NULL)
>>> +};
>>> +
>>> +static const struct acpi_device_id bmc150_magn_acpi_match[] = {
>>> + {"BMC150B", 0},
>>> + {},
>>> +};
>> nitpick, no blank line here. Tends to directly associate the structure
>> with the following macro which is visually nice..
> Sure, I will remove all blank lines you mentioned.
>>> +
>>> +MODULE_DEVICE_TABLE(acpi, bmc150_magn_acpi_match);
>>> +
>>> +static const struct i2c_device_id bmc150_magn_id[] = {
>>> + {"bmc150_magn", 0},
>>> + {},
>>> +};
>> Nitpick, no blank line.
>>> +
>>> +MODULE_DEVICE_TABLE(i2c, bmc150_magn_id);
>>> +
>>> +static struct i2c_driver bmc150_magn_driver = {
>>> + .driver = {
>>> + .name = BMC150_MAGN_DRV_NAME,
>>> + .acpi_match_table = ACPI_PTR(bmc150_magn_acpi_match),
>>> + .pm = &bmc150_magn_pm_ops,
>>> + },
>>> + .probe = bmc150_magn_probe,
>>> + .remove = bmc150_magn_remove,
>>> + .id_table = bmc150_magn_id,
>>> +};
>> Nitpick. I'd not bother with the blank line here.
>>> +
>>> +module_i2c_driver(bmc150_magn_driver);
>>> +
>>> +MODULE_AUTHOR("Irina Tirdea <irina.tirdea@xxxxxxxxx>");
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_DESCRIPTION("BMC150 magnetometer driver");
>>>
>
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