RE: [PATCH v2 1/4] iio: magn: Add support for BMC150 magnetometer
From: Tirdea, Irina
Date: Wed Apr 29 2015 - 14:00:55 EST
> -----Original Message-----
> From: Jonathan Cameron [mailto:jic23@xxxxxxxxxx]
> Sent: 26 April, 2015 20:19
> 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 v2 1/4] iio: magn: Add support for BMC150 magnetometer
>
> On 23/04/15 19:34, Irina Tirdea wrote:
> > Add support for the Bosh BMC150 Magnetometer.
> Bosch. Good start :)
> > 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>
> Very nice. A couple of tiny bits inline. I'd like to leave this
> on the list for a few more days to see if anyone else has any comments
> to add to mine. We are very early in this cycle, so no rush!
>
Thanks for the review, Jonathan!
> Thanks,
>
> Jonathan
> > ---
> > drivers/iio/magnetometer/Kconfig | 14 +
> > drivers/iio/magnetometer/Makefile | 2 +
> > drivers/iio/magnetometer/bmc150_magn.c | 986 +++++++++++++++++++++++++++++++++
> > 3 files changed, 1002 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..b8e4c90
> > --- /dev/null
> > +++ b/drivers/iio/magnetometer/bmc150_magn.c
> > @@ -0,0 +1,986 @@
> > +/*
> > + * 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;
> > + /* 4 x 32 bits for x, y z, 4 bytes align, 64 bits timestamp */
> > + s32 buffer[6];
> > + struct iio_trigger *dready_trig;
> > + bool dready_trigger_on;
> > +};
> > +
> > +static const struct {
> > + int freq;
> > + u8 reg_val;
> > +} bmc150_magn_samp_freq_table[] = { {2, 0x01},
> > + {6, 0x02},
> > + {8, 0x03},
> > + {10, 0x00},
> > + {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,
> > +};
> > +
> > +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;
> > + usleep_range(BMC150_MAGN_START_UP_TIME_MS * 1000, 20000);
> > + 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, ®_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;
> > + 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) {
> > + mutex_unlock(&data->mutex);
> > + 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) {
> > + mutex_unlock(&data->mutex);
> > + 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;
> > + 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;
> > + 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 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), \
> > + .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, \
> Don't bother specifying the shift as it'll be set to 0 anyway.
> (also default in my mind will always be zero anyway for a shift so it
> doesn't serve a documentation purpose either!)
Right, there is no need for shift here.
> > + .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,
> > + .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;
> > +
> > + 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_write(data->regmap, BMC150_MAGN_REG_REP_XY,
> > + 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_write(data->regmap, BMC150_MAGN_REG_REP_Z,
> > + 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;
> > + }
> > +
> > + 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);
> > +}
> > +
> > +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 = request_threaded_irq(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_free_irq;
> > + }
> > +
> > + 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_free_irq:
> > + if (client->irq > 0)
> > + free_irq(client->irq, data->dready_trig);
> > +err_buffer_cleanup:
> > + 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 (client->irq > 0)
> > + free_irq(data->client->irq, data->dready_trig);
> > +
> > + if (data->dready_trig) {
> > + iio_triggered_buffer_cleanup(indio_dev);
> > + iio_trigger_unregister(data->dready_trig);
> > + }
> > +
> > + 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;
> Is EAGAIN a sensible error? Would returning ret not make more sense?
>
I was thinking on forcing some retries for resume, but it's probably not worth it once we have i2c write errors.
I'll change it to ret.
> > + }
> > +
> > + 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},
> > + {},
> > +};
> > +MODULE_DEVICE_TABLE(acpi, bmc150_magn_acpi_match);
> > +
> > +static const struct i2c_device_id bmc150_magn_id[] = {
> > + {"bmc150_magn", 0},
> > + {},
> > +};
> > +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,
> > +};
> > +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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