iio:common: Removed stuff macros, added num_data_channels on st_sensors struct and added support on one-shot sysfs reads to 3 byte channel

This patch introduce num_data_channels variable on st_sensors struct
to manage different type of channels (size or number) in
st_sensors_get_buffer_element function.
Removed ST_SENSORS_NUMBER_DATA_CHANNELS and ST_SENSORS_BYTE_FOR_CHANNEL
and used struct iio_chan_spec const *ch to catch data.
Added 3 byte channel data support on one-shot reads.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

5 files changed, 73 insertions, 31 deletions

diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
index 40236d5d8753..4aec121261d7 100644
--- a/drivers/iio/accel/st_accel_core.c
+++ b/drivers/iio/accel/st_accel_core.c
@@ -26,6 +26,8 @@
 #include <linux/iio/common/st_sensors.h>
 #include "st_accel.h"
 
+#define ST_ACCEL_NUMBER_DATA_CHANNELS           3
+
 /* DEFAULT VALUE FOR SENSORS */
 #define ST_ACCEL_DEFAULT_OUT_X_L_ADDR           0x28
 #define ST_ACCEL_DEFAULT_OUT_Y_L_ADDR           0x2a
@@ -454,6 +456,7 @@ int st_accel_common_probe(struct iio_dev *indio_dev)
         if (err < 0)
                 goto st_accel_common_probe_error;
 
+        adata->num_data_channels = ST_ACCEL_NUMBER_DATA_CHANNELS;
         adata->multiread_bit = adata->sensor->multi_read_bit;
         indio_dev->channels = adata->sensor->ch;
         indio_dev->num_channels = ST_SENSORS_NUMBER_ALL_CHANNELS;
diff --git a/drivers/iio/common/st_sensors/st_sensors_buffer.c b/drivers/iio/common/st_sensors/st_sensors_buffer.c
index 09b236d6ee89..71a2c5f63b9c 100644
--- a/drivers/iio/common/st_sensors/st_sensors_buffer.c
+++ b/drivers/iio/common/st_sensors/st_sensors_buffer.c
@@ -24,11 +24,20 @@
 
 int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
 {
+        u8 *addr;
         int i, n = 0, len;
-        u8 addr[ST_SENSORS_NUMBER_DATA_CHANNELS];
         struct st_sensor_data *sdata = iio_priv(indio_dev);
+        unsigned int num_data_channels = sdata->num_data_channels;
+        unsigned int byte_for_channel =
+                        indio_dev->channels[0].scan_type.storagebits >> 3;
 
-        for (i = 0; i < ST_SENSORS_NUMBER_DATA_CHANNELS; i++) {
+        addr = kmalloc(num_data_channels, GFP_KERNEL);
+        if (!addr) {
+                len = -ENOMEM;
+                goto st_sensors_get_buffer_element_error;
+        }
+
+        for (i = 0; i < num_data_channels; i++) {
                 if (test_bit(i, indio_dev->active_scan_mask)) {
                         addr[n] = indio_dev->channels[i].address;
                         n++;
@@ -37,52 +46,58 @@ int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
         switch (n) {
         case 1:
                 len = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
-                        addr[0], ST_SENSORS_BYTE_FOR_CHANNEL, buf,
-                        sdata->multiread_bit);
+                        addr[0], byte_for_channel, buf, sdata->multiread_bit);
                 break;
         case 2:
-                if ((addr[1] - addr[0]) == ST_SENSORS_BYTE_FOR_CHANNEL) {
+                if ((addr[1] - addr[0]) == byte_for_channel) {
                         len = sdata->tf->read_multiple_byte(&sdata->tb,
-                                        sdata->dev, addr[0],
-                                        ST_SENSORS_BYTE_FOR_CHANNEL*n,
-                                        buf, sdata->multiread_bit);
+                                sdata->dev, addr[0], byte_for_channel * n,
+                                buf, sdata->multiread_bit);
                 } else {
-                        u8 rx_array[ST_SENSORS_BYTE_FOR_CHANNEL*
-                                    ST_SENSORS_NUMBER_DATA_CHANNELS];
+                        u8 *rx_array;
+                        rx_array = kmalloc(byte_for_channel * num_data_channels,
+                                           GFP_KERNEL);
+                        if (!rx_array) {
+                                len = -ENOMEM;
+                                goto st_sensors_free_memory;
+                        }
+
                         len = sdata->tf->read_multiple_byte(&sdata->tb,
                                 sdata->dev, addr[0],
-                                ST_SENSORS_BYTE_FOR_CHANNEL*
-                                ST_SENSORS_NUMBER_DATA_CHANNELS,
+                                byte_for_channel * num_data_channels,
                                 rx_array, sdata->multiread_bit);
-                        if (len < 0)
-                                goto read_data_channels_error;
+                        if (len < 0) {
+                                kfree(rx_array);
+                                goto st_sensors_free_memory;
+                        }
 
-                        for (i = 0; i < n * ST_SENSORS_NUMBER_DATA_CHANNELS;
-                                                                        i++) {
+                        for (i = 0; i < n * num_data_channels; i++) {
                                 if (i < n)
                                         buf[i] = rx_array[i];
                                 else
                                         buf[i] = rx_array[n + i];
                         }
-                        len = ST_SENSORS_BYTE_FOR_CHANNEL*n;
+                        kfree(rx_array);
+                        len = byte_for_channel * n;
                 }
                 break;
         case 3:
                 len = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
-                        addr[0], ST_SENSORS_BYTE_FOR_CHANNEL*
-                        ST_SENSORS_NUMBER_DATA_CHANNELS,
+                        addr[0], byte_for_channel * num_data_channels,
                         buf, sdata->multiread_bit);
                 break;
         default:
                 len = -EINVAL;
-                goto read_data_channels_error;
+                goto st_sensors_free_memory;
         }
-        if (len != ST_SENSORS_BYTE_FOR_CHANNEL*n) {
+        if (len != byte_for_channel * n) {
                 len = -EIO;
-                goto read_data_channels_error;
+                goto st_sensors_free_memory;
         }
 
-read_data_channels_error:
+st_sensors_free_memory:
+        kfree(addr);
+st_sensors_get_buffer_element_error:
         return len;
 }
 EXPORT_SYMBOL(st_sensors_get_buffer_element);
diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c
index ed9bc8ae9330..865b1781df66 100644
--- a/drivers/iio/common/st_sensors/st_sensors_core.c
+++ b/drivers/iio/common/st_sensors/st_sensors_core.c
@@ -20,6 +20,11 @@
 
 #define ST_SENSORS_WAI_ADDRESS          0x0f
 
+static inline u32 st_sensors_get_unaligned_le24(const u8 *p)
+{
+        return ((s32)((p[0] | p[1] << 8 | p[2] << 16) << 8) >> 8);
+}
+
 static int st_sensors_write_data_with_mask(struct iio_dev *indio_dev,
                                                 u8 reg_addr, u8 mask, u8 data)
 {
@@ -112,7 +117,8 @@ st_sensors_match_odr_error:
         return ret;
 }
 
-static int st_sensors_set_fullscale(struct iio_dev *indio_dev, unsigned int fs)
+static int st_sensors_set_fullscale(struct iio_dev *indio_dev,
+                                                        unsigned int fs)
 {
         int err, i = 0;
         struct st_sensor_data *sdata = iio_priv(indio_dev);
@@ -273,21 +279,33 @@ st_sensors_match_scale_error:
 EXPORT_SYMBOL(st_sensors_set_fullscale_by_gain);
 
 static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
-                                                        u8 ch_addr, int *data)
+                                struct iio_chan_spec const *ch, int *data)
 {
         int err;
-        u8 outdata[ST_SENSORS_BYTE_FOR_CHANNEL];
+        u8 *outdata;
         struct st_sensor_data *sdata = iio_priv(indio_dev);
+        unsigned int byte_for_channel = ch->scan_type.storagebits >> 3;
+
+        outdata = kmalloc(byte_for_channel, GFP_KERNEL);
+        if (!outdata) {
+                err = -EINVAL;
+                goto st_sensors_read_axis_data_error;
+        }
 
         err = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
-                                ch_addr, ST_SENSORS_BYTE_FOR_CHANNEL,
+                                ch->address, byte_for_channel,
                                 outdata, sdata->multiread_bit);
         if (err < 0)
-                goto read_error;
+                goto st_sensors_free_memory;
 
-        *data = (s16)get_unaligned_le16(outdata);
+        if (byte_for_channel == 2)
+                *data = (s16)get_unaligned_le16(outdata);
+        else if (byte_for_channel == 3)
+                *data = (s32)st_sensors_get_unaligned_le24(outdata);
 
-read_error:
+st_sensors_free_memory:
+        kfree(outdata);
+st_sensors_read_axis_data_error:
         return err;
 }
 
@@ -307,7 +325,7 @@ int st_sensors_read_info_raw(struct iio_dev *indio_dev,
                         goto read_error;
 
                 msleep((sdata->sensor->bootime * 1000) / sdata->odr);
-                err = st_sensors_read_axis_data(indio_dev, ch->address, val);
+                err = st_sensors_read_axis_data(indio_dev, ch, val);
                 if (err < 0)
                         goto read_error;
 
diff --git a/drivers/iio/gyro/st_gyro_core.c b/drivers/iio/gyro/st_gyro_core.c
index 9bae46bcccee..f9ed3488c314 100644
--- a/drivers/iio/gyro/st_gyro_core.c
+++ b/drivers/iio/gyro/st_gyro_core.c
@@ -27,6 +27,8 @@
 #include <linux/iio/common/st_sensors.h>
 #include "st_gyro.h"
 
+#define ST_GYRO_NUMBER_DATA_CHANNELS            3
+
 /* DEFAULT VALUE FOR SENSORS */
 #define ST_GYRO_DEFAULT_OUT_X_L_ADDR            0x28
 #define ST_GYRO_DEFAULT_OUT_Y_L_ADDR            0x2a
@@ -313,6 +315,7 @@ int st_gyro_common_probe(struct iio_dev *indio_dev)
         if (err < 0)
                 goto st_gyro_common_probe_error;
 
+        gdata->num_data_channels = ST_GYRO_NUMBER_DATA_CHANNELS;
         gdata->multiread_bit = gdata->sensor->multi_read_bit;
         indio_dev->channels = gdata->sensor->ch;
         indio_dev->num_channels = ST_SENSORS_NUMBER_ALL_CHANNELS;
diff --git a/drivers/iio/magnetometer/st_magn_core.c b/drivers/iio/magnetometer/st_magn_core.c
index 715d61681df3..ebfe8f11a0c2 100644
--- a/drivers/iio/magnetometer/st_magn_core.c
+++ b/drivers/iio/magnetometer/st_magn_core.c
@@ -26,6 +26,8 @@
 #include <linux/iio/common/st_sensors.h>
 #include "st_magn.h"
 
+#define ST_MAGN_NUMBER_DATA_CHANNELS            3
+
 /* DEFAULT VALUE FOR SENSORS */
 #define ST_MAGN_DEFAULT_OUT_X_L_ADDR            0X04
 #define ST_MAGN_DEFAULT_OUT_Y_L_ADDR            0X08
@@ -356,6 +358,7 @@ int st_magn_common_probe(struct iio_dev *indio_dev)
         if (err < 0)
                 goto st_magn_common_probe_error;
 
+        mdata->num_data_channels = ST_MAGN_NUMBER_DATA_CHANNELS;
         mdata->multiread_bit = mdata->sensor->multi_read_bit;
         indio_dev->channels = mdata->sensor->ch;
         indio_dev->num_channels = ST_SENSORS_NUMBER_ALL_CHANNELS;