RE: [PATCH 6/7] iio: make st_sensors driver use regmap

Denis CIOCCA
2019-06-26T20:45:47Z

Hi Jonathan,

Thanks for the review. I am replying to this one only but I agree with all your comments.
I am changing the part as suggested (it makes totally sense) for the spi 3-wire initialization. I will submit new series as soon as it is ready.

Thanks
Denis

On Mon, 17 Jun 2019 16:49:42 -0700
Denis Ciocca <denis.ciocca@st.com> wrote:

> This patch remove the transfer functions of the driver and make use of
> regmap. Multi-read bit is checked during probe at first in order to
> configure the regmap and not copied anymore.
> The multi-read bit can be set also for a single read.
>
> Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
A few things inline.

There is an existing oddity around when the spi modes are set that I would suggest cleaning up in a precursor patch to this one.

Jonathan

> ---
> drivers/iio/accel/st_accel_core.c | 3 -
> drivers/iio/accel/st_accel_i2c.c | 7 +-
> drivers/iio/accel/st_accel_spi.c | 6 +-
> .../iio/common/st_sensors/st_sensors_buffer.c | 10 +-
> .../iio/common/st_sensors/st_sensors_core.c | 47 +++-----
> .../iio/common/st_sensors/st_sensors_i2c.c | 65 +++++------
> .../iio/common/st_sensors/st_sensors_spi.c | 103 +++++-------------
> .../common/st_sensors/st_sensors_trigger.c | 10 +-
> drivers/iio/gyro/st_gyro_core.c | 3 -
> drivers/iio/gyro/st_gyro_i2c.c | 5 +-
> drivers/iio/gyro/st_gyro_spi.c | 6 +-
> drivers/iio/magnetometer/st_magn_core.c | 3 -
> drivers/iio/magnetometer/st_magn_i2c.c | 5 +-
> drivers/iio/magnetometer/st_magn_spi.c | 6 +-
> drivers/iio/pressure/st_pressure_core.c | 3 -
> drivers/iio/pressure/st_pressure_i2c.c | 5 +-
> drivers/iio/pressure/st_pressure_spi.c | 6 +-
> include/linux/iio/common/st_sensors.h | 37 +------
> include/linux/iio/common/st_sensors_i2c.h | 5 +-
> include/linux/iio/common/st_sensors_spi.h | 5 +-
> 20 files changed, 126 insertions(+), 214 deletions(-)
>
> diff --git a/drivers/iio/accel/st_accel_core.c
> b/drivers/iio/accel/st_accel_core.c
> index 5029b399efa8..5b8c1ef43ff8 100644
> --- a/drivers/iio/accel/st_accel_core.c
> +++ b/drivers/iio/accel/st_accel_core.c
> @@ -13,7 +13,6 @@
> #include <linux/acpi.h>
> #include <linux/errno.h>
> #include <linux/types.h>
> -#include <linux/mutex.h>
> #include <linux/interrupt.h>
> #include <linux/i2c.h>
> #include <linux/gpio.h>
> @@ -1175,7 +1174,6 @@ int st_accel_common_probe(struct iio_dev
> *indio_dev)
>
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->info = &accel_info;
> - mutex_init(&adata->tb.buf_lock);
>
> err = st_sensors_power_enable(indio_dev);
> if (err)
> @@ -1188,7 +1186,6 @@ int st_accel_common_probe(struct iio_dev *indio_dev)
> goto st_accel_power_off;
>
> adata->num_data_channels = ST_ACCEL_NUMBER_DATA_CHANNELS;
> - adata->multiread_bit = adata->sensor_settings->multi_read_bit;
> indio_dev->num_channels = ST_SENSORS_NUMBER_ALL_CHANNELS;
>
> channels_size = indio_dev->num_channels * sizeof(struct
> iio_chan_spec); diff --git a/drivers/iio/accel/st_accel_i2c.c
> b/drivers/iio/accel/st_accel_i2c.c
> index c3c8f2e73c2a..f2162f8cf2ac 100644
> --- a/drivers/iio/accel/st_accel_i2c.c
> +++ b/drivers/iio/accel/st_accel_i2c.c
> @@ -150,8 +150,8 @@ MODULE_DEVICE_TABLE(i2c, st_accel_id_table);
>
> static int st_accel_i2c_probe(struct i2c_client *client) {
> - struct iio_dev *indio_dev;
> struct st_sensor_data *adata;
> + struct iio_dev *indio_dev;
> const char *match;
> int ret;
>
> @@ -165,7 +165,10 @@ static int st_accel_i2c_probe(struct i2c_client *client)
> if (match)
> strlcpy(client->name, match, sizeof(client->name));
>
> - st_sensors_i2c_configure(indio_dev, client, adata);
> + ret = st_sensors_i2c_configure(indio_dev, client,
> + st_accel_multiread_bit(client->name));
> + if (ret < 0)
> + return ret;
>
> ret = st_accel_common_probe(indio_dev);
> if (ret < 0)
> diff --git a/drivers/iio/accel/st_accel_spi.c
> b/drivers/iio/accel/st_accel_spi.c
> index 474742e35d92..a121755d6d8c 100644
> --- a/drivers/iio/accel/st_accel_spi.c
> +++ b/drivers/iio/accel/st_accel_spi.c
> @@ -114,7 +114,11 @@ static int st_accel_spi_probe(struct spi_device
> *spi)
>
> st_sensors_of_name_probe(&spi->dev, st_accel_of_match,
> spi->modalias, sizeof(spi->modalias));
> - st_sensors_spi_configure(indio_dev, spi, adata);
> +
> + err = st_sensors_spi_configure(indio_dev, spi,
> + st_accel_multiread_bit(spi->modalias));
> + if (err < 0)
> + return err;
>
> err = st_accel_common_probe(indio_dev);
> if (err < 0)
> diff --git a/drivers/iio/common/st_sensors/st_sensors_buffer.c
> b/drivers/iio/common/st_sensors/st_sensors_buffer.c
> index 4a68669dc555..eee30130ae23 100644
> --- a/drivers/iio/common/st_sensors/st_sensors_buffer.c
> +++ b/drivers/iio/common/st_sensors/st_sensors_buffer.c
> @@ -17,15 +17,16 @@
> #include <linux/iio/trigger_consumer.h> #include
> <linux/iio/triggered_buffer.h> #include <linux/irqreturn.h>
> +#include <linux/regmap.h>
>
> #include <linux/iio/common/st_sensors.h>
>
>
> static int st_sensors_get_buffer_element(struct iio_dev *indio_dev,
> u8 *buf) {
> - int i;
> struct st_sensor_data *sdata = iio_priv(indio_dev);
> unsigned int num_data_channels = sdata->num_data_channels;
> + int i;
>
> for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) {
> const struct iio_chan_spec *channel = &indio_dev->channels[i]; @@
> -36,11 +37,8 @@ static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
> channel->scan_type.storagebits >> 3;
>
> buf = PTR_ALIGN(buf, storage_bytes);
> - if (sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
> - channel->address,
> - bytes_to_read, buf,
> - sdata->multiread_bit) <
> - bytes_to_read)
> + if (regmap_bulk_read(sdata->regmap, channel->address,
> + buf, bytes_to_read) < 0)
> return -EIO;
>
> /* Advance the buffer pointer */
> diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c
> b/drivers/iio/common/st_sensors/st_sensors_core.c
> index 243b2097c57e..3ddab3ca0a4b 100644
> --- a/drivers/iio/common/st_sensors/st_sensors_core.c
> +++ b/drivers/iio/common/st_sensors/st_sensors_core.c
> @@ -15,6 +15,7 @@
> #include <linux/regulator/consumer.h> #include <linux/of.h>
> #include <linux/of_device.h>
> +#include <linux/regmap.h>
> #include <asm/unaligned.h>
> #include <linux/iio/common/st_sensors.h>
>
> @@ -28,19 +29,10 @@ static inline u32
> st_sensors_get_unaligned_le24(const u8 *p) int st_sensors_write_data_with_mask(struct iio_dev *indio_dev,
> u8 reg_addr, u8 mask, u8 data) {
> - int err;
> - u8 new_data;
> struct st_sensor_data *sdata = iio_priv(indio_dev);
>
> - err = sdata->tf->read_byte(&sdata->tb, sdata->dev, reg_addr, &new_data);
> - if (err < 0)
> - goto st_sensors_write_data_with_mask_error;
> -
> - new_data = ((new_data & (~mask)) | ((data << __ffs(mask)) & mask));
> - err = sdata->tf->write_byte(&sdata->tb, sdata->dev, reg_addr, new_data);
> -
> -st_sensors_write_data_with_mask_error:
> - return err;
> + return regmap_update_bits(sdata->regmap,
> + reg_addr, mask, data << __ffs(mask));
> }
>
> int st_sensors_debugfs_reg_access(struct iio_dev *indio_dev, @@
> -48,19 +40,15 @@ int st_sensors_debugfs_reg_access(struct iio_dev *indio_dev,
> unsigned *readval)
> {
> struct st_sensor_data *sdata = iio_priv(indio_dev);
> - u8 readdata;
> int err;
>
> if (!readval)
> - return sdata->tf->write_byte(&sdata->tb, sdata->dev,
> - (u8)reg, (u8)writeval);
> + return regmap_write(sdata->regmap, reg, writeval);
>
> - err = sdata->tf->read_byte(&sdata->tb, sdata->dev, (u8)reg, &readdata);
> + err = regmap_read(sdata->regmap, reg, readval);
> if (err < 0)
> return err;
>
> - *readval = (unsigned)readdata;
> -
> return 0;
> }
> EXPORT_SYMBOL(st_sensors_debugfs_reg_access);
> @@ -545,7 +533,7 @@ int st_sensors_set_fullscale_by_gain(struct
> iio_dev *indio_dev, int scale)
> EXPORT_SYMBOL(st_sensors_set_fullscale_by_gain);
>
> static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
> - struct iio_chan_spec const *ch, int *data)
> + struct iio_chan_spec const *ch, int *data)
> {
> int err;
> u8 *outdata;
> @@ -558,9 +546,8 @@ static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
> if (!outdata)
> return -ENOMEM;
>
> - err = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
> - ch->address, byte_for_channel,
> - outdata, sdata->multiread_bit);
> + err = regmap_bulk_read(sdata->regmap, ch->address,
> + outdata, byte_for_channel);
> if (err < 0)
> goto st_sensors_free_memory;
>
> @@ -608,8 +595,9 @@ int st_sensors_read_info_raw(struct iio_dev
> *indio_dev, } EXPORT_SYMBOL(st_sensors_read_info_raw);
>
> -static int st_sensors_init_interface_mode(struct iio_dev *indio_dev,
> - const struct st_sensor_settings *sensor_settings)
> +static int
> +st_sensors_init_interface_mode(struct iio_dev *indio_dev,
> + const struct st_sensor_settings *sensor_settings)
> {
> struct st_sensor_data *sdata = iio_priv(indio_dev);
> struct device_node *np = sdata->dev->of_node; @@ -620,9 +608,9 @@
> static int st_sensors_init_interface_mode(struct iio_dev *indio_dev,
> (pdata && pdata->spi_3wire)) && sensor_settings->sim.addr) {
> int err;
>
> - err = sdata->tf->write_byte(&sdata->tb, sdata->dev,
> - sensor_settings->sim.addr,
> - sensor_settings->sim.value);
> + err = regmap_bulk_write(sdata->regmap,

As mentioned below, I'm fairly sure bulk_read/write require dma safe buffers.
Though why are you using bulk_write for length 1?

Even more interesting this is spi specific. I would move it to before the spi regmap stuff is setup at all then just do a normal spi_write.

> + sensor_settings->sim.addr,
> + &sensor_settings->sim.value, 1);
> if (err < 0) {
> dev_err(&indio_dev->dev,
> "failed to init interface mode\n"); @@ -667,8 +655,7 @@ int
> st_sensors_check_device_support(struct iio_dev *indio_dev,
> const struct st_sensor_settings *sensor_settings) {
> struct st_sensor_data *sdata = iio_priv(indio_dev);
> - int i, err = 0;
> - u8 wai;
> + int i, wai, err = 0;
>
> i = st_sensors_get_settings_index(indio_dev->name,
> sensor_settings, num_sensors_list); @@ -683,8 +670,8 @@ int
> st_sensors_check_device_support(struct iio_dev *indio_dev,
> return err;
>
> if (sensor_settings[i].wai_addr) {
> - err = sdata->tf->read_byte(&sdata->tb, sdata->dev,
> - sensor_settings[i].wai_addr, &wai);
> + err = regmap_read(sdata->regmap,
> + sensor_settings[i].wai_addr, &wai);
> if (err < 0) {
> dev_err(&indio_dev->dev,
> "failed to read Who-Am-I register.\n"); diff --git
> a/drivers/iio/common/st_sensors/st_sensors_i2c.c
> b/drivers/iio/common/st_sensors/st_sensors_i2c.c
> index b1c9812407e7..c8e03a63b17b 100644
> --- a/drivers/iio/common/st_sensors/st_sensors_i2c.c
> +++ b/drivers/iio/common/st_sensors/st_sensors_i2c.c
> @@ -13,6 +13,7 @@
> #include <linux/iio/iio.h>
> #include <linux/of_device.h>
> #include <linux/acpi.h>
> +#include <linux/regmap.h>
>
> #include <linux/iio/common/st_sensors_i2c.h>
>
> @@ -26,55 +27,45 @@ static unsigned int st_sensors_i2c_get_irq(struct iio_dev *indio_dev)
> return to_i2c_client(sdata->dev)->irq; }
>
> -static int st_sensors_i2c_read_byte(struct st_sensor_transfer_buffer *tb,
> - struct device *dev, u8 reg_addr, u8 *res_byte)
> -{
> - int err;
> -
> - err = i2c_smbus_read_byte_data(to_i2c_client(dev), reg_addr);
> - if (err < 0)
> - goto st_accel_i2c_read_byte_error;
> -
> - *res_byte = err & 0xff;
> -
> -st_accel_i2c_read_byte_error:
> - return err < 0 ? err : 0;
> -}
> -
> -static int st_sensors_i2c_read_multiple_byte(
> - struct st_sensor_transfer_buffer *tb, struct device *dev,
> - u8 reg_addr, int len, u8 *data, bool multiread_bit)
> -{
> - if (multiread_bit)
> - reg_addr |= ST_SENSORS_I2C_MULTIREAD;
> +static const struct regmap_config st_sensors_i2c_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> +};
>
> - return i2c_smbus_read_i2c_block_data_or_emulated(to_i2c_client(dev),
> - reg_addr, len, data);
> -}
> +static const struct regmap_config st_sensors_i2c_regmap_multiread_bit_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .read_flag_mask = ST_SENSORS_I2C_MULTIREAD, };
>
> -static int st_sensors_i2c_write_byte(struct st_sensor_transfer_buffer *tb,
> - struct device *dev, u8 reg_addr, u8 data)
> +int st_sensors_i2c_configure(struct iio_dev *indio_dev,
> + struct i2c_client *client,
> + bool multiread_bit)
> {
> - return i2c_smbus_write_byte_data(to_i2c_client(dev), reg_addr, data);
> -}
> + struct st_sensor_data *sdata = iio_priv(indio_dev);
> + const struct regmap_config *config;
>
> -static const struct st_sensor_transfer_function st_sensors_tf_i2c = {
> - .read_byte = st_sensors_i2c_read_byte,
> - .write_byte = st_sensors_i2c_write_byte,
> - .read_multiple_byte = st_sensors_i2c_read_multiple_byte,
> -};
> + if (multiread_bit)
> + config = &st_sensors_i2c_regmap_multiread_bit_config;
> + else
> + config = &st_sensors_i2c_regmap_config;
> +
> + sdata->regmap = devm_regmap_init_i2c(client, config);
> + if (IS_ERR(sdata->regmap)) {
> + dev_err(&client->dev, "Failed to register i2c regmap (%d)\n",
> + (int)PTR_ERR(sdata->regmap));
> + return PTR_ERR(sdata->regmap);
> + }
>
> -void st_sensors_i2c_configure(struct iio_dev *indio_dev,
> - struct i2c_client *client, struct st_sensor_data *sdata)
> -{
> i2c_set_clientdata(client, indio_dev);
>
> indio_dev->dev.parent = &client->dev;
> indio_dev->name = client->name;
>
> sdata->dev = &client->dev;
> - sdata->tf = &st_sensors_tf_i2c;
> sdata->get_irq_data_ready = st_sensors_i2c_get_irq;
> +
> + return 0;
> }
> EXPORT_SYMBOL(st_sensors_i2c_configure);
>
> diff --git a/drivers/iio/common/st_sensors/st_sensors_spi.c
> b/drivers/iio/common/st_sensors/st_sensors_spi.c
> index 2213843f02cb..bf3627be4b8a 100644
> --- a/drivers/iio/common/st_sensors/st_sensors_spi.c
> +++ b/drivers/iio/common/st_sensors/st_sensors_spi.c
> @@ -11,12 +11,12 @@
> #include <linux/module.h>
> #include <linux/slab.h>
> #include <linux/iio/iio.h>
> +#include <linux/regmap.h>
>
> #include <linux/iio/common/st_sensors_spi.h>
>
>
> #define ST_SENSORS_SPI_MULTIREAD 0xc0
> -#define ST_SENSORS_SPI_READ 0x80
>
> static unsigned int st_sensors_spi_get_irq(struct iio_dev *indio_dev)
> { @@ -25,94 +25,45 @@ static unsigned int
> st_sensors_spi_get_irq(struct iio_dev *indio_dev)
> return to_spi_device(sdata->dev)->irq; }
>
> -static int st_sensors_spi_read(struct st_sensor_transfer_buffer *tb,
> - struct device *dev, u8 reg_addr, int len, u8 *data, bool multiread_bit)
> -{
> - int err;
> -
> - struct spi_transfer xfers[] = {
> - {
> - .tx_buf = tb->tx_buf,
> - .bits_per_word = 8,
> - .len = 1,
> - },
> - {
> - .rx_buf = tb->rx_buf,
> - .bits_per_word = 8,
> - .len = len,
> - }
> - };
> -
> - mutex_lock(&tb->buf_lock);
> - if ((multiread_bit) && (len > 1))
> - tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_MULTIREAD;
> - else
> - tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_READ;
> -
> - err = spi_sync_transfer(to_spi_device(dev), xfers, ARRAY_SIZE(xfers));
> - if (err)
> - goto acc_spi_read_error;
> -
> - memcpy(data, tb->rx_buf, len);
> - mutex_unlock(&tb->buf_lock);
> - return len;
> -
> -acc_spi_read_error:
> - mutex_unlock(&tb->buf_lock);
> - return err;
> -}
> -
> -static int st_sensors_spi_read_byte(struct st_sensor_transfer_buffer *tb,
> - struct device *dev, u8 reg_addr, u8 *res_byte)
> -{
> - return st_sensors_spi_read(tb, dev, reg_addr, 1, res_byte, false);
> -}
> +static const struct regmap_config st_sensors_spi_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> +};
>
> -static int st_sensors_spi_read_multiple_byte(
> - struct st_sensor_transfer_buffer *tb, struct device *dev,
> - u8 reg_addr, int len, u8 *data, bool multiread_bit)
> -{
> - return st_sensors_spi_read(tb, dev, reg_addr, len, data, multiread_bit);
> -}
> +static const struct regmap_config st_sensors_spi_regmap_multiread_bit_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .read_flag_mask = ST_SENSORS_SPI_MULTIREAD, };
>
> -static int st_sensors_spi_write_byte(struct st_sensor_transfer_buffer *tb,
> - struct device *dev, u8 reg_addr, u8 data)
> +int st_sensors_spi_configure(struct iio_dev *indio_dev,
> + struct spi_device *spi,
> + bool multiread_bit)
> {
> - int err;
> -
> - struct spi_transfer xfers = {
> - .tx_buf = tb->tx_buf,
> - .bits_per_word = 8,
> - .len = 2,
> - };
> -
> - mutex_lock(&tb->buf_lock);
> - tb->tx_buf[0] = reg_addr;
> - tb->tx_buf[1] = data;
> -
> - err = spi_sync_transfer(to_spi_device(dev), &xfers, 1);
> - mutex_unlock(&tb->buf_lock);
> + struct st_sensor_data *sdata = iio_priv(indio_dev);
> + const struct regmap_config *config;
>
> - return err;
> -}
> + if (multiread_bit)
> + config = &st_sensors_spi_regmap_multiread_bit_config;
> + else
> + config = &st_sensors_spi_regmap_config;
>
> -static const struct st_sensor_transfer_function st_sensors_tf_spi = {
> - .read_byte = st_sensors_spi_read_byte,
> - .write_byte = st_sensors_spi_write_byte,
> - .read_multiple_byte = st_sensors_spi_read_multiple_byte,
> -};
> + sdata->regmap = devm_regmap_init_spi(spi, config);
> + if (IS_ERR(sdata->regmap)) {
> + dev_err(&spi->dev, "Failed to register spi regmap (%d)\n",
> + (int)PTR_ERR(sdata->regmap));
> + return PTR_ERR(sdata->regmap);
> + }
>
> -void st_sensors_spi_configure(struct iio_dev *indio_dev,
> - struct spi_device *spi, struct st_sensor_data *sdata)
> -{
> spi_set_drvdata(spi, indio_dev);
>
> indio_dev->dev.parent = &spi->dev;
> indio_dev->name = spi->modalias;
>
> sdata->dev = &spi->dev;
> - sdata->tf = &st_sensors_tf_spi;
> sdata->get_irq_data_ready = st_sensors_spi_get_irq;
> +
> + return 0;
> }
> EXPORT_SYMBOL(st_sensors_spi_configure);
>
> diff --git a/drivers/iio/common/st_sensors/st_sensors_trigger.c
> b/drivers/iio/common/st_sensors/st_sensors_trigger.c
> index 630c8cb35e8b..bed7b8682b17 100644
> --- a/drivers/iio/common/st_sensors/st_sensors_trigger.c
> +++ b/drivers/iio/common/st_sensors/st_sensors_trigger.c
> @@ -13,6 +13,7 @@
> #include <linux/iio/iio.h>
> #include <linux/iio/trigger.h>
> #include <linux/interrupt.h>
> +#include <linux/regmap.h>
> #include <linux/iio/common/st_sensors.h> #include
> "st_sensors_core.h"
>
> @@ -26,8 +27,7 @@
> static int st_sensors_new_samples_available(struct iio_dev *indio_dev,
> struct st_sensor_data *sdata) {
> - u8 status;
> - int ret;
> + int ret, status;
>
> /* How would I know if I can't check it? */
> if (!sdata->sensor_settings->drdy_irq.stat_drdy.addr)
> @@ -37,9 +37,9 @@ static int st_sensors_new_samples_available(struct iio_dev *indio_dev,
> if (!indio_dev->active_scan_mask)
> return 0;
>
> - ret = sdata->tf->read_byte(&sdata->tb, sdata->dev,
> - sdata->sensor_settings->drdy_irq.stat_drdy.addr,
> - &status);
> + ret = regmap_read(sdata->regmap,
> + sdata->sensor_settings->drdy_irq.stat_drdy.addr,
> + &status);
> if (ret < 0) {
> dev_err(sdata->dev,
> "error checking samples available\n"); diff --git
> a/drivers/iio/gyro/st_gyro_core.c b/drivers/iio/gyro/st_gyro_core.c
> index 84a014fdcad2..5223b3118221 100644
> --- a/drivers/iio/gyro/st_gyro_core.c
> +++ b/drivers/iio/gyro/st_gyro_core.c
> @@ -12,7 +12,6 @@
> #include <linux/slab.h>
> #include <linux/errno.h>
> #include <linux/types.h>
> -#include <linux/mutex.h>
> #include <linux/interrupt.h>
> #include <linux/i2c.h>
> #include <linux/gpio.h>
> @@ -392,7 +391,6 @@ int st_gyro_common_probe(struct iio_dev
> *indio_dev)
>
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->info = &gyro_info;
> - mutex_init(&gdata->tb.buf_lock);
>
> err = st_sensors_power_enable(indio_dev);
> if (err)
> @@ -405,7 +403,6 @@ int st_gyro_common_probe(struct iio_dev *indio_dev)
> goto st_gyro_power_off;
>
> gdata->num_data_channels = ST_GYRO_NUMBER_DATA_CHANNELS;
> - gdata->multiread_bit = gdata->sensor_settings->multi_read_bit;
> indio_dev->channels = gdata->sensor_settings->ch;
> indio_dev->num_channels = ST_SENSORS_NUMBER_ALL_CHANNELS;
>
> diff --git a/drivers/iio/gyro/st_gyro_i2c.c
> b/drivers/iio/gyro/st_gyro_i2c.c index f2a8683db7d9..fa560f68e022
> 100644
> --- a/drivers/iio/gyro/st_gyro_i2c.c
> +++ b/drivers/iio/gyro/st_gyro_i2c.c
> @@ -77,7 +77,10 @@ static int st_gyro_i2c_probe(struct i2c_client *client,
> st_sensors_of_name_probe(&client->dev, st_gyro_of_match,
> client->name, sizeof(client->name));
>
> - st_sensors_i2c_configure(indio_dev, client, gdata);
> + err = st_sensors_i2c_configure(indio_dev, client,
> + st_gyro_multiread_bit(client->name));
> + if (err < 0)
> + return err;
>
> err = st_gyro_common_probe(indio_dev);
> if (err < 0)
> diff --git a/drivers/iio/gyro/st_gyro_spi.c
> b/drivers/iio/gyro/st_gyro_spi.c index 93c48248bea6..9bb58d2d72ed
> 100644
> --- a/drivers/iio/gyro/st_gyro_spi.c
> +++ b/drivers/iio/gyro/st_gyro_spi.c
> @@ -81,7 +81,11 @@ static int st_gyro_spi_probe(struct spi_device
> *spi)
>
> st_sensors_of_name_probe(&spi->dev, st_gyro_of_match,
> spi->modalias, sizeof(spi->modalias));
> - st_sensors_spi_configure(indio_dev, spi, gdata);
> +
> + err = st_sensors_spi_configure(indio_dev, spi,
> + st_gyro_multiread_bit(spi->modalias));
> + if (err < 0)
> + return err;
>
> err = st_gyro_common_probe(indio_dev);
> if (err < 0)
> diff --git a/drivers/iio/magnetometer/st_magn_core.c
> b/drivers/iio/magnetometer/st_magn_core.c
> index 2d8919eb5ada..4aa118e72ef6 100644
> --- a/drivers/iio/magnetometer/st_magn_core.c
> +++ b/drivers/iio/magnetometer/st_magn_core.c
> @@ -12,7 +12,6 @@
> #include <linux/slab.h>
> #include <linux/errno.h>
> #include <linux/types.h>
> -#include <linux/mutex.h>
> #include <linux/interrupt.h>
> #include <linux/i2c.h>
> #include <linux/gpio.h>
> @@ -494,7 +493,6 @@ int st_magn_common_probe(struct iio_dev
> *indio_dev)
>
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->info = &magn_info;
> - mutex_init(&mdata->tb.buf_lock);
>
> err = st_sensors_power_enable(indio_dev);
> if (err)
> @@ -507,7 +505,6 @@ int st_magn_common_probe(struct iio_dev *indio_dev)
> goto st_magn_power_off;
>
> mdata->num_data_channels = ST_MAGN_NUMBER_DATA_CHANNELS;
> - mdata->multiread_bit = mdata->sensor_settings->multi_read_bit;
> indio_dev->channels = mdata->sensor_settings->ch;
> indio_dev->num_channels = ST_SENSORS_NUMBER_ALL_CHANNELS;
>
> diff --git a/drivers/iio/magnetometer/st_magn_i2c.c
> b/drivers/iio/magnetometer/st_magn_i2c.c
> index 4d014fd1aeb0..52e9be5088be 100644
> --- a/drivers/iio/magnetometer/st_magn_i2c.c
> +++ b/drivers/iio/magnetometer/st_magn_i2c.c
> @@ -69,7 +69,10 @@ static int st_magn_i2c_probe(struct i2c_client *client,
> st_sensors_of_name_probe(&client->dev, st_magn_of_match,
> client->name, sizeof(client->name));
>
> - st_sensors_i2c_configure(indio_dev, client, mdata);
> + err = st_sensors_i2c_configure(indio_dev, client,
> + st_magn_multiread_bit(client->name));
> + if (err < 0)
> + return err;
>
> err = st_magn_common_probe(indio_dev);
> if (err < 0)
> diff --git a/drivers/iio/magnetometer/st_magn_spi.c
> b/drivers/iio/magnetometer/st_magn_spi.c
> index 0d47070611b1..80c32a1720cd 100644
> --- a/drivers/iio/magnetometer/st_magn_spi.c
> +++ b/drivers/iio/magnetometer/st_magn_spi.c
> @@ -63,7 +63,11 @@ static int st_magn_spi_probe(struct spi_device
> *spi)
>
> st_sensors_of_name_probe(&spi->dev, st_magn_of_match,
> spi->modalias, sizeof(spi->modalias));
> - st_sensors_spi_configure(indio_dev, spi, mdata);
> +
> + err = st_sensors_spi_configure(indio_dev, spi,
> + st_magn_multiread_bit(spi->modalias));
> + if (err < 0)
> + return err;
>
> err = st_magn_common_probe(indio_dev);
> if (err < 0)
> diff --git a/drivers/iio/pressure/st_pressure_core.c
> b/drivers/iio/pressure/st_pressure_core.c
> index fb3bfaa00e85..9160ccfbef59 100644
> --- a/drivers/iio/pressure/st_pressure_core.c
> +++ b/drivers/iio/pressure/st_pressure_core.c
> @@ -12,7 +12,6 @@
> #include <linux/slab.h>
> #include <linux/errno.h>
> #include <linux/types.h>
> -#include <linux/mutex.h>
> #include <linux/interrupt.h>
> #include <linux/i2c.h>
> #include <linux/gpio.h>
> @@ -690,7 +689,6 @@ int st_press_common_probe(struct iio_dev
> *indio_dev)
>
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->info = &press_info;
> - mutex_init(&press_data->tb.buf_lock);
>
> err = st_sensors_power_enable(indio_dev);
> if (err)
> @@ -709,7 +707,6 @@ int st_press_common_probe(struct iio_dev *indio_dev)
> * element.
> */
> press_data->num_data_channels = press_data->sensor_settings->num_ch - 1;
> - press_data->multiread_bit = press_data->sensor_settings->multi_read_bit;
> indio_dev->channels = press_data->sensor_settings->ch;
> indio_dev->num_channels = press_data->sensor_settings->num_ch;
>
> diff --git a/drivers/iio/pressure/st_pressure_i2c.c
> b/drivers/iio/pressure/st_pressure_i2c.c
> index b7d9ba706abc..97468ca16dd5 100644
> --- a/drivers/iio/pressure/st_pressure_i2c.c
> +++ b/drivers/iio/pressure/st_pressure_i2c.c
> @@ -103,7 +103,10 @@ static int st_press_i2c_probe(struct i2c_client *client,
> } else if (!id)
> return -ENODEV;
>
> - st_sensors_i2c_configure(indio_dev, client, press_data);
> + ret = st_sensors_i2c_configure(indio_dev, client,
> + st_press_multiread_bit(client->name));
> + if (ret < 0)
> + return ret;
>
> ret = st_press_common_probe(indio_dev);
> if (ret < 0)
> diff --git a/drivers/iio/pressure/st_pressure_spi.c
> b/drivers/iio/pressure/st_pressure_spi.c
> index ef61401c41d3..ae2fbcb2169e 100644
> --- a/drivers/iio/pressure/st_pressure_spi.c
> +++ b/drivers/iio/pressure/st_pressure_spi.c
> @@ -73,7 +73,11 @@ static int st_press_spi_probe(struct spi_device
> *spi)
>
> st_sensors_of_name_probe(&spi->dev, st_press_of_match,
> spi->modalias, sizeof(spi->modalias));
> - st_sensors_spi_configure(indio_dev, spi, press_data);
> +
> + err = st_sensors_spi_configure(indio_dev, spi,
> + st_press_multiread_bit(spi->modalias));
> + if (err < 0)
> + return err;
>
> err = st_press_common_probe(indio_dev);
> if (err < 0)
> diff --git a/include/linux/iio/common/st_sensors.h
> b/include/linux/iio/common/st_sensors.h
> index 17fbf3e9b013..edd7a538f58c 100644
> --- a/include/linux/iio/common/st_sensors.h
> +++ b/include/linux/iio/common/st_sensors.h
> @@ -16,6 +16,7 @@
> #include <linux/iio/trigger.h>
> #include <linux/bitops.h>
> #include <linux/regulator/consumer.h>
> +#include <linux/regmap.h>
>
> #include <linux/platform_data/st_sensors_pdata.h>
>
> @@ -169,36 +170,6 @@ struct st_sensor_data_ready_irq {
> } ig1;
> };
>
> -/**
> - * struct st_sensor_transfer_buffer - ST sensor device I/O buffer
> - * @buf_lock: Mutex to protect rx and tx buffers.
> - * @tx_buf: Buffer used by SPI transfer function to send data to the sensors.
> - * This buffer is used to avoid DMA not-aligned issue.
> - * @rx_buf: Buffer used by SPI transfer to receive data from sensors.
> - * This buffer is used to avoid DMA not-aligned issue.
> - */
> -struct st_sensor_transfer_buffer {
> - struct mutex buf_lock;
> - u8 rx_buf[ST_SENSORS_RX_MAX_LENGTH];
> - u8 tx_buf[ST_SENSORS_TX_MAX_LENGTH] ____cacheline_aligned;

I'm slightly interested to see this go. Note that the bulk reads in regmap still need dma aligned buffers I believe.
Looking above it seems like there may be one problem case.

> -};
> -
> -/**
> - * struct st_sensor_transfer_function - ST sensor device I/O function
> - * @read_byte: Function used to read one byte.
> - * @write_byte: Function used to write one byte.
> - * @read_multiple_byte: Function used to read multiple byte.
> - */
> -struct st_sensor_transfer_function {
> - int (*read_byte) (struct st_sensor_transfer_buffer *tb,
> - struct device *dev, u8 reg_addr, u8 *res_byte);
> - int (*write_byte) (struct st_sensor_transfer_buffer *tb,
> - struct device *dev, u8 reg_addr, u8 data);
> - int (*read_multiple_byte) (struct st_sensor_transfer_buffer *tb,
> - struct device *dev, u8 reg_addr, int len, u8 *data,
> - bool multiread_bit);
> -};
> -
> /**
> * struct st_sensor_settings - ST specific sensor settings
> * @wai: Contents of WhoAmI register.
> @@ -243,7 +214,6 @@ struct st_sensor_settings {
> * @vdd: Pointer to sensor's Vdd power supply
> * @vdd_io: Pointer to sensor's Vdd-IO power supply
> * @enabled: Status of the sensor (false->off, true->on).
> - * @multiread_bit: Use or not particular bit for [I2C/SPI] multiread.
> * @buffer_data: Data used by buffer part.
> * @odr: Output data rate of the sensor [Hz].
> * num_data_channels: Number of data channels used in buffer.
> @@ -264,9 +234,9 @@ struct st_sensor_data {
> struct st_sensor_fullscale_avl *current_fullscale;
> struct regulator *vdd;
> struct regulator *vdd_io;
> + struct regmap *regmap;

I'm guessing this should be in the docs?

>
> bool enabled;
> - bool multiread_bit;
>
> char *buffer_data;
>
> @@ -278,9 +248,6 @@ struct st_sensor_data {
>
> unsigned int (*get_irq_data_ready) (struct iio_dev *indio_dev);
>
> - const struct st_sensor_transfer_function *tf;
> - struct st_sensor_transfer_buffer tb;
> -

And these have docs entries that should go.

> bool edge_irq;
> bool hw_irq_trigger;
> s64 hw_timestamp;
> diff --git a/include/linux/iio/common/st_sensors_i2c.h
> b/include/linux/iio/common/st_sensors_i2c.h
> index 5ada89944698..4d8f44d32ce9 100644
> --- a/include/linux/iio/common/st_sensors_i2c.h
> +++ b/include/linux/iio/common/st_sensors_i2c.h
> @@ -14,8 +14,9 @@
> #include <linux/iio/common/st_sensors.h> #include <linux/of.h>
>
> -void st_sensors_i2c_configure(struct iio_dev *indio_dev,
> - struct i2c_client *client, struct st_sensor_data *sdata);
> +int st_sensors_i2c_configure(struct iio_dev *indio_dev,
> + struct i2c_client *client,
> + bool multiread_bit);
>
> #ifdef CONFIG_ACPI
> int st_sensors_match_acpi_device(struct device *dev); diff --git
> a/include/linux/iio/common/st_sensors_spi.h
> b/include/linux/iio/common/st_sensors_spi.h
> index 6020f7167859..77c5f4d18cc6 100644
> --- a/include/linux/iio/common/st_sensors_spi.h
> +++ b/include/linux/iio/common/st_sensors_spi.h
> @@ -13,7 +13,8 @@
> #include <linux/spi/spi.h>
> #include <linux/iio/common/st_sensors.h>
>
> -void st_sensors_spi_configure(struct iio_dev *indio_dev,
> - struct spi_device *spi, struct st_sensor_data *sdata);
> +int st_sensors_spi_configure(struct iio_dev *indio_dev,
> + struct spi_device *spi,
> + bool multiread_bit);
>
> #endif /* ST_SENSORS_SPI_H */