iio: magnetometer: mag3110: Factor out core of read/write_raw() and use guard() to...

The combination of guard(mutex) and factoring out sections of code
that occur with the device held in direct mode simplifies code flow.

Reviewed-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://patch.msgid.link/20250331121317.1694135-22-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/magnetometer/mag3110.c b/drivers/iio/magnetometer/mag3110.c
index 2fe8e97f2cf86385b9bb342171b85a857e2151c3..b633bdf793ed8f3bb42618d8669b009d5b73c58a 100644 (file)
--- a/drivers/iio/magnetometer/mag3110.c
+++ b/drivers/iio/magnetometer/mag3110.c
@@ -9,6 +9,7 @@
  * TODO: irq, user offset, oversampling, continuous mode
  */
 
+#include <linux/cleanup.h>
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/iio/iio.h>
@@ -102,17 +103,12 @@ static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
 {
        int ret;
 
-       mutex_lock(&data->lock);
+       guard(mutex)(&data->lock);
        ret = mag3110_request(data);
-       if (ret < 0) {
-               mutex_unlock(&data->lock);
+       if (ret < 0)
                return ret;
-       }
-       ret = i2c_smbus_read_i2c_block_data(data->client,
-               MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
-       mutex_unlock(&data->lock);
-
-       return ret;
+       return i2c_smbus_read_i2c_block_data(data->client, MAG3110_OUT_X,
+                                            3 * sizeof(__be16), (u8 *) buf);
 }
 
 static ssize_t mag3110_show_int_plus_micros(char *buf,
@@ -231,19 +227,17 @@ static int mag3110_change_config(struct mag3110_data *data, u8 reg, u8 val)
        int ret;
        int is_active;
 
-       mutex_lock(&data->lock);
+       guard(mutex)(&data->lock);
 
        is_active = mag3110_is_active(data);
-       if (is_active < 0) {
-               ret = is_active;
-               goto fail;
-       }
+       if (is_active < 0)
+               return is_active;
 
        /* config can only be changed when in standby */
        if (is_active > 0) {
                ret = mag3110_standby(data);
                if (ret < 0)
-                       goto fail;
+                       return ret;
        }
 
        /*
@@ -252,23 +246,52 @@ static int mag3110_change_config(struct mag3110_data *data, u8 reg, u8 val)
         */
        ret = mag3110_wait_standby(data);
        if (ret < 0)
-               goto fail;
+               return ret;
 
        ret = i2c_smbus_write_byte_data(data->client, reg, val);
        if (ret < 0)
-               goto fail;
+               return ret;
 
        if (is_active > 0) {
                ret = mag3110_active(data);
                if (ret < 0)
-                       goto fail;
+                       return ret;
        }
 
-       ret = 0;
-fail:
-       mutex_unlock(&data->lock);
+       return 0;
+}
 
-       return ret;
+static int __mag3110_read_info_raw(struct mag3110_data *data,
+                                  struct iio_chan_spec const *chan,
+                                  int *val)
+{
+       __be16 buffer[3];
+       int ret;
+
+       switch (chan->type) {
+       case IIO_MAGN: /* in 0.1 uT / LSB */
+               ret = mag3110_read(data, buffer);
+               if (ret < 0)
+                       return ret;
+               *val = sign_extend32(be16_to_cpu(buffer[chan->scan_index]),
+                                    chan->scan_type.realbits - 1);
+               return IIO_VAL_INT;
+
+       case IIO_TEMP: { /* in 1 C / LSB */
+               guard(mutex)(&data->lock);
+               ret = mag3110_request(data);
+               if (ret < 0)
+                       return ret;
+               ret = i2c_smbus_read_byte_data(data->client,
+                                              MAG3110_DIE_TEMP);
+               if (ret < 0)
+                       return ret;
+               *val = sign_extend32(ret, chan->scan_type.realbits - 1);
+               return IIO_VAL_INT;
+       }
+       default:
+               return -EINVAL;
+       }
 }
 
 static int mag3110_read_raw(struct iio_dev *indio_dev,
@@ -276,7 +299,6 @@ static int mag3110_read_raw(struct iio_dev *indio_dev,
                            int *val, int *val2, long mask)
 {
        struct mag3110_data *data = iio_priv(indio_dev);
-       __be16 buffer[3];
        int i, ret;
 
        switch (mask) {
@@ -284,37 +306,7 @@ static int mag3110_read_raw(struct iio_dev *indio_dev,
                ret = iio_device_claim_direct_mode(indio_dev);
                if (ret)
                        return ret;
-
-               switch (chan->type) {
-               case IIO_MAGN: /* in 0.1 uT / LSB */
-                       ret = mag3110_read(data, buffer);
-                       if (ret < 0)
-                               goto release;
-                       *val = sign_extend32(
-                               be16_to_cpu(buffer[chan->scan_index]),
-                                           chan->scan_type.realbits - 1);
-                       ret = IIO_VAL_INT;
-                       break;
-               case IIO_TEMP: /* in 1 C / LSB */
-                       mutex_lock(&data->lock);
-                       ret = mag3110_request(data);
-                       if (ret < 0) {
-                               mutex_unlock(&data->lock);
-                               goto release;
-                       }
-                       ret = i2c_smbus_read_byte_data(data->client,
-                               MAG3110_DIE_TEMP);
-                       mutex_unlock(&data->lock);
-                       if (ret < 0)
-                               goto release;
-                       *val = sign_extend32(ret,
-                                            chan->scan_type.realbits - 1);
-                       ret = IIO_VAL_INT;
-                       break;
-               default:
-                       ret = -EINVAL;
-               }
-release:
+               ret = __mag3110_read_info_raw(data, chan, val);
                iio_device_release_direct_mode(indio_dev);
                return ret;
 
@@ -346,24 +338,18 @@ release:
        return -EINVAL;
 }
 
-static int mag3110_write_raw(struct iio_dev *indio_dev,
-                            struct iio_chan_spec const *chan,
-                            int val, int val2, long mask)
+static int __mag3110_write_raw(struct mag3110_data *data,
+                             struct iio_chan_spec const *chan,
+                             int val, int val2, long mask)
 {
-       struct mag3110_data *data = iio_priv(indio_dev);
-       int rate, ret;
-
-       ret = iio_device_claim_direct_mode(indio_dev);
-       if (ret)
-               return ret;
+       int rate;
 
        switch (mask) {
        case IIO_CHAN_INFO_SAMP_FREQ:
                rate = mag3110_get_samp_freq_index(data, val, val2);
-               if (rate < 0) {
-                       ret = -EINVAL;
-                       break;
-               }
+               if (rate < 0)
+                       return -EINVAL;
+
                data->ctrl_reg1 &= 0xff & ~MAG3110_CTRL_DR_MASK
                                        & ~MAG3110_CTRL_AC;
                data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
@@ -371,22 +357,33 @@ static int mag3110_write_raw(struct iio_dev *indio_dev,
                if (data->sleep_val < 40)
                        data->ctrl_reg1 |= MAG3110_CTRL_AC;
 
-               ret = mag3110_change_config(data, MAG3110_CTRL_REG1,
-                                           data->ctrl_reg1);
-               break;
+               return mag3110_change_config(data, MAG3110_CTRL_REG1,
+                                            data->ctrl_reg1);
+
        case IIO_CHAN_INFO_CALIBBIAS:
-               if (val < -10000 || val > 10000) {
-                       ret = -EINVAL;
-                       break;
-               }
-               ret = i2c_smbus_write_word_swapped(data->client,
+               if (val < -10000 || val > 10000)
+                       return -EINVAL;
+
+               return i2c_smbus_write_word_swapped(data->client,
                        MAG3110_OFF_X + 2 * chan->scan_index, val << 1);
-               break;
        default:
-               ret = -EINVAL;
-               break;
+               return -EINVAL;
        }
+}
+
+static int mag3110_write_raw(struct iio_dev *indio_dev,
+                            struct iio_chan_spec const *chan,
+                            int val, int val2, long mask)
+{
+       struct mag3110_data *data = iio_priv(indio_dev);
+       int ret;
+
+       ret = iio_device_claim_direct_mode(indio_dev);
+       if (ret)
+               return ret;
+       ret = __mag3110_write_raw(data, chan, val, val2, mask);
        iio_device_release_direct_mode(indio_dev);
+
        return ret;
 }