iio: move 3-wire spi initialization to st_sensors_spi

Some devices need to be configured with special bit in order to
use spi 3-wire. This was done during device identification phase.
Instead, let's move this part as spi specific.
Doing this the check_device_support function becomes a simple
device id check, so let's rename it.

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

12 files changed, 97 insertions, 71 deletions

diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
index 6fc490ffef7e..630909702a19 100644
--- a/drivers/iio/accel/st_accel_core.c
+++ b/drivers/iio/accel/st_accel_core.c
@@ -1183,9 +1183,7 @@ int st_accel_common_probe(struct iio_dev *indio_dev)
         if (err)
                 return err;
 
-        err = st_sensors_check_device_support(indio_dev,
-                                        ARRAY_SIZE(st_accel_sensors_settings),
-                                        st_accel_sensors_settings);
+        err = st_sensors_verify_id(indio_dev);
         if (err < 0)
                 goto st_accel_power_off;
 
diff --git a/drivers/iio/accel/st_accel_spi.c b/drivers/iio/accel/st_accel_spi.c
index c0556db9d60a..8af7027d5598 100644
--- a/drivers/iio/accel/st_accel_spi.c
+++ b/drivers/iio/accel/st_accel_spi.c
@@ -124,7 +124,9 @@ static int st_accel_spi_probe(struct spi_device *spi)
         adata = iio_priv(indio_dev);
         adata->sensor_settings = (struct st_sensor_settings *)settings;
 
-        st_sensors_spi_configure(indio_dev, spi, adata);
+        err = st_sensors_spi_configure(indio_dev, spi);
+        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_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c
index 3610ca9eaa87..f05bf7cf0594 100644
--- a/drivers/iio/common/st_sensors/st_sensors_core.c
+++ b/drivers/iio/common/st_sensors/st_sensors_core.c
@@ -608,31 +608,6 @@ out:
 }
 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)
-{
-        struct st_sensor_data *sdata = iio_priv(indio_dev);
-        struct device_node *np = sdata->dev->of_node;
-        struct st_sensors_platform_data *pdata;
-
-        pdata = (struct st_sensors_platform_data *)sdata->dev->platform_data;
-        if (((np && of_property_read_bool(np, "spi-3wire")) ||
-             (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);
-                if (err < 0) {
-                        dev_err(&indio_dev->dev,
-                                "failed to init interface mode\n");
-                        return err;
-                }
-        }
-
-        return 0;
-}
-
 /*
  * st_sensors_get_settings_index() - get index of the sensor settings for a
  *                                   specific device from list of settings
@@ -660,36 +635,30 @@ int st_sensors_get_settings_index(const char *name,
 }
 EXPORT_SYMBOL(st_sensors_get_settings_index);
 
-int st_sensors_check_device_support(struct iio_dev *indio_dev,
-                        int num_sensors_list,
-                        const struct st_sensor_settings *sensor_settings)
+/*
+ * st_sensors_verify_id() - verify sensor ID (WhoAmI) is matching with the
+ *                          expected value
+ * @indio_dev: IIO device reference.
+ *
+ * Return: 0 on success (valid sensor ID), else a negative error code.
+ */
+int st_sensors_verify_id(struct iio_dev *indio_dev)
 {
         struct st_sensor_data *sdata = iio_priv(indio_dev);
-        int i, err;
+        int err;
         u8 wai;
 
-        i = st_sensors_get_settings_index(indio_dev->name,
-                                          sensor_settings, num_sensors_list);
-        if (i < 0) {
-                dev_err(&indio_dev->dev, "device name %s not recognized.\n",
-                        indio_dev->name);
-                return i;
-        }
-
-        err = st_sensors_init_interface_mode(indio_dev, &sensor_settings[i]);
-        if (err < 0)
-                return err;
-
-        if (sensor_settings[i].wai_addr) {
+        if (sdata->sensor_settings->wai_addr) {
                 err = sdata->tf->read_byte(&sdata->tb, sdata->dev,
-                                           sensor_settings[i].wai_addr, &wai);
+                                           sdata->sensor_settings->wai_addr,
+                                           &wai);
                 if (err < 0) {
                         dev_err(&indio_dev->dev,
                                 "failed to read Who-Am-I register.\n");
                         return err;
                 }
 
-                if (sensor_settings[i].wai != wai) {
+                if (sdata->sensor_settings->wai != wai) {
                         dev_err(&indio_dev->dev,
                                 "%s: WhoAmI mismatch (0x%x).\n",
                                 indio_dev->name, wai);
@@ -697,12 +666,9 @@ int st_sensors_check_device_support(struct iio_dev *indio_dev,
                 }
         }
 
-        sdata->sensor_settings =
-                        (struct st_sensor_settings *)&sensor_settings[i];
-
-        return i;
+        return 0;
 }
-EXPORT_SYMBOL(st_sensors_check_device_support);
+EXPORT_SYMBOL(st_sensors_verify_id);
 
 ssize_t st_sensors_sysfs_sampling_frequency_avail(struct device *dev,
                                 struct device_attribute *attr, char *buf)
diff --git a/drivers/iio/common/st_sensors/st_sensors_spi.c b/drivers/iio/common/st_sensors/st_sensors_spi.c
index 2213843f02cb..a57cd648975c 100644
--- a/drivers/iio/common/st_sensors/st_sensors_spi.c
+++ b/drivers/iio/common/st_sensors/st_sensors_spi.c
@@ -102,9 +102,68 @@ static const struct st_sensor_transfer_function st_sensors_tf_spi = {
         .read_multiple_byte = st_sensors_spi_read_multiple_byte,
 };
 
-void st_sensors_spi_configure(struct iio_dev *indio_dev,
-                        struct spi_device *spi, struct st_sensor_data *sdata)
+/*
+ * st_sensors_is_spi_3_wire() - check if SPI 3-wire mode has been selected
+ * @spi: spi device reference.
+ *
+ * Return: true if SPI 3-wire mode is selected, false otherwise.
+ */
+static bool st_sensors_is_spi_3_wire(struct spi_device *spi)
+{
+        struct device_node *np = spi->dev.of_node;
+        struct st_sensors_platform_data *pdata;
+
+        pdata = (struct st_sensors_platform_data *)spi->dev.platform_data;
+        if ((np && of_property_read_bool(np, "spi-3wire")) ||
+            (pdata && pdata->spi_3wire)) {
+                return true;
+        }
+
+        return false;
+}
+
+/*
+ * st_sensors_configure_spi_3_wire() - configure SPI 3-wire if needed
+ * @spi: spi device reference.
+ * @settings: sensor specific settings reference.
+ *
+ * Return: 0 on success, else a negative error code.
+ */
+static int st_sensors_configure_spi_3_wire(struct spi_device *spi,
+                                           struct st_sensor_settings *settings)
+{
+        if (settings->sim.addr) {
+                u8 buffer[] = {
+                        settings->sim.addr,
+                        settings->sim.value
+                };
+
+                return spi_write(spi, buffer, 2);
+        }
+
+        return 0;
+}
+
+/*
+ * st_sensors_spi_configure() - configure SPI interface
+ * @indio_dev: IIO device reference.
+ * @spi: spi device reference.
+ *
+ * Return: 0 on success, else a negative error code.
+ */
+int st_sensors_spi_configure(struct iio_dev *indio_dev,
+                             struct spi_device *spi)
 {
+        struct st_sensor_data *sdata = iio_priv(indio_dev);
+        int err;
+
+        if (st_sensors_is_spi_3_wire(spi)) {
+                err = st_sensors_configure_spi_3_wire(spi,
+                                                      sdata->sensor_settings);
+                if (err < 0)
+                        return err;
+        }
+
         spi_set_drvdata(spi, indio_dev);
 
         indio_dev->dev.parent = &spi->dev;
@@ -113,6 +172,8 @@ void st_sensors_spi_configure(struct iio_dev *indio_dev,
         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/gyro/st_gyro_core.c b/drivers/iio/gyro/st_gyro_core.c
index 5cc63d41d855..4b87e79aa744 100644
--- a/drivers/iio/gyro/st_gyro_core.c
+++ b/drivers/iio/gyro/st_gyro_core.c
@@ -400,9 +400,7 @@ int st_gyro_common_probe(struct iio_dev *indio_dev)
         if (err)
                 return err;
 
-        err = st_sensors_check_device_support(indio_dev,
-                                        ARRAY_SIZE(st_gyro_sensors_settings),
-                                        st_gyro_sensors_settings);
+        err = st_sensors_verify_id(indio_dev);
         if (err < 0)
                 goto st_gyro_power_off;
 
diff --git a/drivers/iio/gyro/st_gyro_spi.c b/drivers/iio/gyro/st_gyro_spi.c
index bb7082055f85..b5c624251231 100644
--- a/drivers/iio/gyro/st_gyro_spi.c
+++ b/drivers/iio/gyro/st_gyro_spi.c
@@ -91,7 +91,9 @@ static int st_gyro_spi_probe(struct spi_device *spi)
         gdata = iio_priv(indio_dev);
         gdata->sensor_settings = (struct st_sensor_settings *)settings;
 
-        st_sensors_spi_configure(indio_dev, spi, gdata);
+        err = st_sensors_spi_configure(indio_dev, spi);
+        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 43a49a52c81a..3f313aefece6 100644
--- a/drivers/iio/magnetometer/st_magn_core.c
+++ b/drivers/iio/magnetometer/st_magn_core.c
@@ -502,9 +502,7 @@ int st_magn_common_probe(struct iio_dev *indio_dev)
         if (err)
                 return err;
 
-        err = st_sensors_check_device_support(indio_dev,
-                                        ARRAY_SIZE(st_magn_sensors_settings),
-                                        st_magn_sensors_settings);
+        err = st_sensors_verify_id(indio_dev);
         if (err < 0)
                 goto st_magn_power_off;
 
diff --git a/drivers/iio/magnetometer/st_magn_spi.c b/drivers/iio/magnetometer/st_magn_spi.c
index a3045afc6b53..fbf909bde841 100644
--- a/drivers/iio/magnetometer/st_magn_spi.c
+++ b/drivers/iio/magnetometer/st_magn_spi.c
@@ -73,7 +73,9 @@ static int st_magn_spi_probe(struct spi_device *spi)
         mdata = iio_priv(indio_dev);
         mdata->sensor_settings = (struct st_sensor_settings *)settings;
 
-        st_sensors_spi_configure(indio_dev, spi, mdata);
+        err = st_sensors_spi_configure(indio_dev, spi);
+        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 35d80ff27464..a783fc075c26 100644
--- a/drivers/iio/pressure/st_pressure_core.c
+++ b/drivers/iio/pressure/st_pressure_core.c
@@ -698,9 +698,7 @@ int st_press_common_probe(struct iio_dev *indio_dev)
         if (err)
                 return err;
 
-        err = st_sensors_check_device_support(indio_dev,
-                                        ARRAY_SIZE(st_press_sensors_settings),
-                                        st_press_sensors_settings);
+        err = st_sensors_verify_id(indio_dev);
         if (err < 0)
                 goto st_press_power_off;
 
diff --git a/drivers/iio/pressure/st_pressure_spi.c b/drivers/iio/pressure/st_pressure_spi.c
index 3e8c1ffe001e..7c8b70221e70 100644
--- a/drivers/iio/pressure/st_pressure_spi.c
+++ b/drivers/iio/pressure/st_pressure_spi.c
@@ -83,7 +83,9 @@ static int st_press_spi_probe(struct spi_device *spi)
         press_data = iio_priv(indio_dev);
         press_data->sensor_settings = (struct st_sensor_settings *)settings;
 
-        st_sensors_spi_configure(indio_dev, spi, press_data);
+        err = st_sensors_spi_configure(indio_dev, spi);
+        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..566b955e2980 100644
--- a/include/linux/iio/common/st_sensors.h
+++ b/include/linux/iio/common/st_sensors.h
@@ -338,8 +338,7 @@ int st_sensors_get_settings_index(const char *name,
                                   const struct st_sensor_settings *list,
                                   const int list_length);
 
-int st_sensors_check_device_support(struct iio_dev *indio_dev,
-        int num_sensors_list, const struct st_sensor_settings *sensor_settings);
+int st_sensors_verify_id(struct iio_dev *indio_dev);
 
 ssize_t st_sensors_sysfs_sampling_frequency_avail(struct device *dev,
                                 struct device_attribute *attr, char *buf);
diff --git a/include/linux/iio/common/st_sensors_spi.h b/include/linux/iio/common/st_sensors_spi.h
index 6020f7167859..90b25f087f06 100644
--- a/include/linux/iio/common/st_sensors_spi.h
+++ b/include/linux/iio/common/st_sensors_spi.h
@@ -13,7 +13,7 @@
 #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);
 
 #endif /* ST_SENSORS_SPI_H */