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Subject[PATCH 2/3] iio: magn: Add support for BMC150 magnetometer
Date
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@bosch.sensortec.com.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
---
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@bosch.sensortec.com:
+ *
+ * (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,
+};
+
+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)
+ 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);
+ 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,
+ 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. */
+ 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);
+}
+
+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:
+ 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);
+ }
+ 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},
+ {},
+};
+
+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@intel.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("BMC150 magnetometer driver");
--
1.9.1


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