[PATCH v2 08/14] iio: accel: bma220: migrate to regmap API

Petre Rodan
2025-09-10T07:58:12Z

Switch to regmap API.

Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro>
---
ChangeLog:
- cleanup patch by splitting out unrelated changes
---
drivers/iio/accel/Kconfig | 2 +
drivers/iio/accel/bma220.h | 6 +-
drivers/iio/accel/bma220_core.c | 266 ++++++++++++++++++++++++++++------------
drivers/iio/accel/bma220_spi.c | 10 +-
4 files changed, 200 insertions(+), 84 deletions(-)

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 2cc3075e26883df60b5068c73b0551e1dd02c32e..9b6c35b759481df5ff3c91856f8783357d25de80 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -218,6 +218,7 @@ config BMA180

config BMA220
tristate "Bosch BMA220 3-Axis Accelerometer Driver"
+ select REGMAP
select IIO_BUFFER
select IIO_TRIGGERED_BUFFER
select BMA220_SPI if SPI
@@ -231,6 +232,7 @@ config BMA220

config BMA220_SPI
tristate
+ select REGMAP_SPI
depends on BMA220

config BMA400
diff --git a/drivers/iio/accel/bma220.h b/drivers/iio/accel/bma220.h
index eb311183ebfe37d1a75d858d435eac777efc4ed8..f9f4fa3daf33665f07f8bf073468dff070b46d74 100644
--- a/drivers/iio/accel/bma220.h
+++ b/drivers/iio/accel/bma220.h
@@ -9,11 +9,11 @@
#define _BMA220_H

#include <linux/pm.h>
-#include <linux/spi/spi.h>
+#include <linux/regmap.h>

+extern const struct regmap_config bma220_spi_regmap_config;
extern const struct dev_pm_ops bma220_pm_ops;
-struct spi_device;

-int bma220_common_probe(struct spi_device *dev);
+int bma220_common_probe(struct device *dev, struct regmap *regmap, int irq);

#endif
diff --git a/drivers/iio/accel/bma220_core.c b/drivers/iio/accel/bma220_core.c
index 322df516c90a7c645eeca579cae9803eb31caad1..4d8b65ea737a2d5fe74f98da13a582a80874a5af 100644
--- a/drivers/iio/accel/bma220_core.c
+++ b/drivers/iio/accel/bma220_core.c
@@ -3,17 +3,21 @@
* BMA220 Digital triaxial acceleration sensor driver
*
* Copyright (c) 2016,2020 Intel Corporation.
+ * Copyright (c) 2025 Petre Rodan <petre.rodan@subdimension.ro>
*/

#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pm.h>
+#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/types.h>
-#include <linux/spi/spi.h>

#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
@@ -24,16 +28,64 @@
#include "bma220.h"

#define BMA220_REG_ID 0x00
+#define BMA220_REG_REVISION_ID 0x01
#define BMA220_REG_ACCEL_X 0x02
#define BMA220_REG_ACCEL_Y 0x03
#define BMA220_REG_ACCEL_Z 0x04
+#define BMA220_REG_CONF0 0x05
+#define BMA220_HIGH_DUR_MSK GENMASK(5, 0)
+#define BMA220_HIGH_HY_MSK GENMASK(7, 6)
+#define BMA220_REG_CONF1 0x06
+#define BMA220_HIGH_TH_MSK GENMASK(3, 0)
+#define BMA220_LOW_TH_MSK GENMASK(7, 4)
+#define BMA220_REG_CONF2 0x07
+#define BMA220_LOW_DUR_MSK GENMASK(5, 0)
+#define BMA220_LOW_HY_MSK GENMASK(7, 6)
+#define BMA220_REG_CONF3 0x08
+#define BMA220_TT_DUR_MSK GENMASK(2, 0)
+#define BMA220_TT_TH_MSK GENMASK(6, 3)
+#define BMA220_REG_CONF4 0x09
+#define BMA220_SLOPE_DUR_MSK GENMASK(1, 0)
+#define BMA220_SLOPE_TH_MSK GENMASK(5, 2)
+#define BMA220_REG_CONF5 0x0a
+#define BMA220_TIP_EN_MSK BIT(4)
+#define BMA220_REG_IF0 0x0b
+#define BMA220_REG_IF1 0x0c
+#define BMA220_IF_SLOPE BIT(0)
+#define BMA220_IF_DRDY BIT(1)
+#define BMA220_IF_HIGH BIT(2)
+#define BMA220_IF_LOW BIT(3)
+#define BMA220_IF_TT BIT(4)
+#define BMA220_REG_IE0 0x0d
+#define BMA220_INT_EN_TAP_Z_MSK BIT(0)
+#define BMA220_INT_EN_TAP_Y_MSK BIT(1)
+#define BMA220_INT_EN_TAP_X_MSK BIT(2)
+#define BMA220_INT_EN_SLOPE_Z_MSK BIT(3)
+#define BMA220_INT_EN_SLOPE_Y_MSK BIT(4)
+#define BMA220_INT_EN_SLOPE_X_MSK BIT(5)
+#define BMA220_INT_EN_DRDY_MSK BIT(7)
+#define BMA220_REG_IE1 0x0e
+#define BMA220_INT_EN_HIGH_Z_MSK BIT(0)
+#define BMA220_INT_EN_HIGH_Y_MSK BIT(1)
+#define BMA220_INT_EN_HIGH_X_MSK BIT(2)
+#define BMA220_INT_EN_LOW_MSK BIT(3)
+#define BMA220_INT_LATCH_MSK GENMASK(6, 4)
+#define BMA220_INT_LATCH_MAX 0x7
+#define BMA220_INT_RST_MSK BIT(7)
+#define BMA220_REG_IE2 0x0f
+#define BMA220_REG_FILTER 0x10
+#define BMA220_FILTER_MASK GENMASK(3, 0)
#define BMA220_REG_RANGE 0x11
+#define BMA220_RANGE_MASK GENMASK(1, 0)
+#define BMA220_REG_WDT 0x17
+#define BMA220_WDT_MASK GENMASK(2, 1)
+#define BMA220_WDT_OFF 0x0
+#define BMA220_WDT_1MS BIT(1)
+#define BMA220_WDT_10MS GENMASK(1, 0)
#define BMA220_REG_SUSPEND 0x18
#define BMA220_REG_SOFTRESET 0x19

#define BMA220_CHIP_ID 0xDD
-#define BMA220_READ_MASK BIT(7)
-#define BMA220_RANGE_MASK GENMASK(1, 0)
#define BMA220_SUSPEND_SLEEP 0xFF
#define BMA220_SUSPEND_WAKE 0x00
#define BMA220_RESET_MODE 0xFF
@@ -69,14 +121,15 @@ static const int bma220_scale_table[][2] = {
};

struct bma220_data {
- struct spi_device *spi_device;
+ struct device *dev;
+ struct regmap *regmap;
struct mutex lock;
+ u8 range_idx;
struct {
s8 chans[3];
/* Ensure timestamp is naturally aligned. */
aligned_s64 timestamp;
- } scan;
- u8 tx_buf[2] __aligned(IIO_DMA_MINALIGN);
+ } scan __aligned(IIO_DMA_MINALIGN);
};

static const struct iio_chan_spec bma220_channels[] = {
@@ -86,35 +139,57 @@ static const struct iio_chan_spec bma220_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(3),
};

-static inline int bma220_read_reg(struct spi_device *spi, u8 reg)
-{
- return spi_w8r8(spi, reg | BMA220_READ_MASK);
-}
-
static const unsigned long bma220_accel_scan_masks[] = {
BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
0
};

+static bool bma220_is_writable_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case BMA220_REG_CONF0:
+ case BMA220_REG_CONF1:
+ case BMA220_REG_CONF2:
+ case BMA220_REG_CONF3:
+ case BMA220_REG_CONF4:
+ case BMA220_REG_CONF5:
+ case BMA220_REG_IE0:
+ case BMA220_REG_IE1:
+ case BMA220_REG_IE2:
+ case BMA220_REG_FILTER:
+ case BMA220_REG_RANGE:
+ case BMA220_REG_WDT:
+ return true;
+ default:
+ return false;
+ }
+}
+
+const struct regmap_config bma220_spi_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .read_flag_mask = BIT(7),
+ .max_register = BMA220_REG_SOFTRESET,
+ .cache_type = REGCACHE_NONE,
+ .writeable_reg = bma220_is_writable_reg,
+};
+EXPORT_SYMBOL_NS_GPL(bma220_spi_regmap_config, "IIO_BOSCH_BMA220");
+
static irqreturn_t bma220_trigger_handler(int irq, void *p)
{
int ret;
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct bma220_data *data = iio_priv(indio_dev);
- struct spi_device *spi = data->spi_device;

- mutex_lock(&data->lock);
- data->tx_buf[0] = BMA220_REG_ACCEL_X | BMA220_READ_MASK;
- ret = spi_write_then_read(spi, data->tx_buf, 1, &data->scan.chans,
- ARRAY_SIZE(bma220_channels) - 1);
+ ret = regmap_bulk_read(data->regmap, BMA220_REG_ACCEL_X,
+ &data->scan.chans,
+ sizeof(data->scan.chans));
if (ret < 0)
- goto err;
+ return IRQ_NONE;

iio_push_to_buffers_with_ts(indio_dev, &data->scan, sizeof(data->scan),
- pf->timestamp);
-err:
- mutex_unlock(&data->lock);
+ iio_get_time_ns(indio_dev));
iio_trigger_notify_done(indio_dev->trig);

return IRQ_HANDLED;
@@ -125,58 +200,65 @@ static int bma220_read_raw(struct iio_dev *indio_dev,
int *val, int *val2, long mask)
{
int ret;
- u8 range_idx;
+ u8 index;
+ unsigned int reg;
struct bma220_data *data = iio_priv(indio_dev);

switch (mask) {
case IIO_CHAN_INFO_RAW:
- ret = bma220_read_reg(data->spi_device, chan->address);
+ ret = regmap_read(data->regmap, chan->address, &reg);
if (ret < 0)
return -EINVAL;
- *val = sign_extend32(ret >> chan->scan_type.shift,
+ *val = sign_extend32(reg >> chan->scan_type.shift,
chan->scan_type.realbits - 1);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
- ret = bma220_read_reg(data->spi_device, BMA220_REG_RANGE);
- if (ret < 0)
- return ret;
- range_idx = ret & BMA220_RANGE_MASK;
- *val = bma220_scale_table[range_idx][0];
- *val2 = bma220_scale_table[range_idx][1];
+ index = data->range_idx;
+ *val = bma220_scale_table[index][0];
+ *val2 = bma220_scale_table[index][1];
return IIO_VAL_INT_PLUS_MICRO;
}

return -EINVAL;
}

+static int bma220_find_match_2dt(const int (*tbl)[2], const int n,
+ const int val, const int val2)
+{
+ int i;
+
+ for (i = 0; i < n; i++) {
+ if (tbl[i][0] == val && tbl[i][1] == val2)
+ return i;
+ }
+
+ return -EINVAL;
+}
+
static int bma220_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
- int i;
int ret;
int index = -1;
struct bma220_data *data = iio_priv(indio_dev);

+ guard(mutex)(&data->lock);
+
switch (mask) {
case IIO_CHAN_INFO_SCALE:
- for (i = 0; i < ARRAY_SIZE(bma220_scale_table); i++)
- if (val == bma220_scale_table[i][0] &&
- val2 == bma220_scale_table[i][1]) {
- index = i;
- break;
- }
+ index = bma220_find_match_2dt(bma220_scale_table,
+ ARRAY_SIZE(bma220_scale_table),
+ val, val2);
if (index < 0)
return -EINVAL;

- mutex_lock(&data->lock);
- data->tx_buf[0] = BMA220_REG_RANGE;
- data->tx_buf[1] = index;
- ret = spi_write(data->spi_device, data->tx_buf,
- sizeof(data->tx_buf));
+ ret = regmap_update_bits(data->regmap, BMA220_REG_RANGE,
+ BMA220_RANGE_MASK,
+ FIELD_PREP(BMA220_RANGE_MASK, index));
if (ret < 0)
return ret;
- mutex_unlock(&data->lock);
+ data->range_idx = index;

return 0;
}
@@ -206,9 +288,12 @@ static const struct iio_info bma220_info = {
.read_avail = bma220_read_avail,
};

-static int bma220_reset(struct spi_device *spi, bool up)
+static int bma220_reset(struct bma220_data *data, bool up)
{
int i, ret;
+ unsigned int val;
+
+ guard(mutex)(&data->lock);

/**
* The chip can be reset by a simple register read.
@@ -216,89 +301,113 @@ static int bma220_reset(struct spi_device *spi, bool up)
* to make sure that the device is in the desired state.
*/
for (i = 0; i < 2; i++) {
- ret = bma220_read_reg(spi, BMA220_REG_SOFTRESET);
+ ret = regmap_read(data->regmap, BMA220_REG_SOFTRESET, &val);
if (ret < 0)
return ret;

- if (up && (ret == BMA220_RESET_MODE))
+ if (up && (val == BMA220_RESET_MODE))
return 0;

- if (!up && (ret == BMA220_NONRESET_MODE))
+ if (!up && (val == BMA220_NONRESET_MODE))
return 0;
}

return -EBUSY;
}

-static int bma220_power(struct spi_device *spi, bool up)
+static int bma220_power(struct bma220_data *data, bool up)
{
int i, ret;
+ unsigned int val;

+ guard(mutex)(&data->lock);
/**
* The chip can be suspended/woken up by a simple register read.
* So, we need up to 2 register reads of the suspend register
* to make sure that the device is in the desired state.
*/
for (i = 0; i < 2; i++) {
- ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
+ ret = regmap_read(data->regmap, BMA220_REG_SUSPEND, &val);
if (ret < 0)
return ret;

- if (up && (ret == BMA220_SUSPEND_SLEEP))
+ if (up && (val == BMA220_SUSPEND_SLEEP))
return 0;

- if (!up && (ret == BMA220_SUSPEND_WAKE))
+ if (!up && (val == BMA220_SUSPEND_WAKE))
return 0;
}

return -EBUSY;
}

-static int bma220_init(struct spi_device *spi)
+
+static int bma220_init(struct bma220_data *data)
{
int ret;
+ unsigned int val;
+ struct device *dev = data->dev;
static const char * const regulator_names[] = { "vddd", "vddio", "vdda" };

- ret = devm_regulator_bulk_get_enable(&spi->dev,
+ ret = devm_regulator_bulk_get_enable(dev,
ARRAY_SIZE(regulator_names),
regulator_names);
if (ret)
- return dev_err_probe(&spi->dev, ret, "Failed to get regulators\n");
+ return dev_err_probe(dev, ret, "Failed to get regulators\n");

- ret = bma220_read_reg(spi, BMA220_REG_ID);
- if (ret != BMA220_CHIP_ID)
+ /* Try to read chip_id register. It must return 0xdd. */
+ ret = regmap_read(data->regmap, BMA220_REG_ID, &val);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to read chip id register\n");
+
+ if (val != BMA220_CHIP_ID)
return -ENODEV;

- /* Make sure the chip is powered on and config registers are reset */
- ret = bma220_power(spi, true);
+ ret = bma220_power(data, true);
if (ret)
- return dev_err_probe(&spi->dev, ret, "Failed to power-on chip\n");
+ return dev_err_probe(dev, ret, "Failed to power-on chip\n");

- ret = bma220_reset(spi, true);
+ ret = bma220_reset(data, true);
if (ret)
- return dev_err_probe(&spi->dev, ret, "Failed to soft reset chip\n");
+ return dev_err_probe(dev, ret, "Failed to soft reset chip\n");

return 0;
}

-static void bma220_deinit(void *spi)
+static void bma220_deinit(void *data_ptr)
{
- bma220_power(spi, false);
+ struct bma220_data *data = data_ptr;
+ int ret;
+
+ ret = bma220_power(data, false);
+ if (ret)
+ dev_warn(data->dev,
+ "Failed to put device into suspend mode (%pe)\n",
+ ERR_PTR(ret));
}

-int bma220_common_probe(struct spi_device *spi)
+int bma220_common_probe(struct device *dev, struct regmap *regmap, int irq)
{
int ret;
struct iio_dev *indio_dev;
struct bma220_data *data;

- indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;

data = iio_priv(indio_dev);
- data->spi_device = spi;
- mutex_init(&data->lock);
+ data->regmap = regmap;
+ data->dev = dev;
+
+ ret = bma220_init(data);
+ if (ret)
+ return ret;
+
+ ret = devm_mutex_init(dev, &data->lock);
+ if (ret)
+ return ret;

indio_dev->info = &bma220_info;
indio_dev->name = BMA220_DEVICE_NAME;
@@ -307,38 +416,35 @@ int bma220_common_probe(struct spi_device *spi)
indio_dev->num_channels = ARRAY_SIZE(bma220_channels);
indio_dev->available_scan_masks = bma220_accel_scan_masks;

- ret = bma220_init(data->spi_device);
+ ret = devm_add_action_or_reset(dev, bma220_deinit, data);
if (ret)
return ret;

- ret = devm_add_action_or_reset(&spi->dev, bma220_deinit, spi);
- if (ret)
- return ret;
-
- ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
- iio_pollfunc_store_time,
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
bma220_trigger_handler, NULL);
if (ret < 0) {
- dev_err(&spi->dev, "iio triggered buffer setup failed\n");
+ dev_err(dev, "iio triggered buffer setup failed\n");
return ret;
}

- return devm_iio_device_register(&spi->dev, indio_dev);
+ return devm_iio_device_register(dev, indio_dev);
}
-EXPORT_SYMBOL_NS(bma220_common_probe, "IIO_BOSCH_BMA220");
+EXPORT_SYMBOL_NS_GPL(bma220_common_probe, "IIO_BOSCH_BMA220");

static int bma220_suspend(struct device *dev)
{
- struct spi_device *spi = to_spi_device(dev);
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct bma220_data *data = iio_priv(indio_dev);

- return bma220_power(spi, false);
+ return bma220_power(data, false);
}

static int bma220_resume(struct device *dev)
{
- struct spi_device *spi = to_spi_device(dev);
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct bma220_data *data = iio_priv(indio_dev);

- return bma220_power(spi, true);
+ return bma220_power(data, true);
}
EXPORT_NS_SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume,
IIO_BOSCH_BMA220);
diff --git a/drivers/iio/accel/bma220_spi.c b/drivers/iio/accel/bma220_spi.c
index 78820d90e39119d9755b6266a8329e11ffd55723..7364428b3e363950d3be2a03b7657a2f0315fc5b 100644
--- a/drivers/iio/accel/bma220_spi.c
+++ b/drivers/iio/accel/bma220_spi.c
@@ -9,6 +9,7 @@
#include <linux/errno.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
+#include <linux/regmap.h>
#include <linux/types.h>
#include <linux/spi/spi.h>

@@ -18,7 +19,14 @@

static int bma220_spi_probe(struct spi_device *spi)
{
- return bma220_common_probe(spi);
+ struct regmap *regmap;
+
+ regmap = devm_regmap_init_spi(spi, &bma220_spi_regmap_config);
+ if (IS_ERR(regmap))
+ return dev_err_probe(&spi->dev, PTR_ERR(regmap),
+ "failed to create regmap\n");
+
+ return bma220_common_probe(&spi->dev, regmap, spi->irq);
}

static const struct spi_device_id bma220_spi_id[] = {

--
2.49.1