Use regmap for i2c register access.  This simplifies register accesses and
chooses suitable access commands based on the functionality that the
adapter supports.

Cc: Matt Ranostay <matt.ranos...@konsulko.com>
Cc: Sakari Ailus <sakari.ai...@linux.intel.com>
Cc: Hans Verkuil <hansv...@cisco.com>
Cc: Mauro Carvalho Chehab <mche...@kernel.org>
Acked-by: Matt Ranostay <matt.ranos...@konsulko.com>
Acked-by: Sakari Ailus <sakari.ai...@linux.intel.com>
Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com>
---
* v3
- Use regmap_init_i2c() instead of devm_regmap_init_i2c() and call
  regmap_exit_i2c() in video device release() callback in order to
  avoid releasing regmap when the driver is unbound.
- Add Acked-by lines

 drivers/media/i2c/video-i2c.c | 68 ++++++++++++++++++++++++++-----------------
 1 file changed, 41 insertions(+), 27 deletions(-)

diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
index f27d294..f23cb91 100644
--- a/drivers/media/i2c/video-i2c.c
+++ b/drivers/media/i2c/video-i2c.c
@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of_device.h>
+#include <linux/regmap.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/videodev2.h>
@@ -38,7 +39,7 @@ struct video_i2c_buffer {
 };
 
 struct video_i2c_data {
-       struct i2c_client *client;
+       struct regmap *regmap;
        const struct video_i2c_chip *chip;
        struct mutex lock;
        spinlock_t slock;
@@ -62,6 +63,12 @@ static const struct v4l2_frmsize_discrete amg88xx_size = {
        .height = 8,
 };
 
+static const struct regmap_config amg88xx_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 8,
+       .max_register = 0xff
+};
+
 struct video_i2c_chip {
        /* video dimensions */
        const struct v4l2_fmtdesc *format;
@@ -76,6 +83,8 @@ struct video_i2c_chip {
        /* pixel size in bits */
        unsigned int bpp;
 
+       const struct regmap_config *regmap_config;
+
        /* xfer function */
        int (*xfer)(struct video_i2c_data *data, char *buf);
 
@@ -83,26 +92,16 @@ struct video_i2c_chip {
        int (*hwmon_init)(struct video_i2c_data *data);
 };
 
-static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
-{
-       struct i2c_client *client = data->client;
-       struct i2c_msg msg[2];
-       u8 reg = 0x80;
-       int ret;
-
-       msg[0].addr = client->addr;
-       msg[0].flags = 0;
-       msg[0].len = 1;
-       msg[0].buf  = (char *)&reg;
+/* Thermistor register */
+#define AMG88XX_REG_TTHL       0x0e
 
-       msg[1].addr = client->addr;
-       msg[1].flags = I2C_M_RD;
-       msg[1].len = data->chip->buffer_size;
-       msg[1].buf = (char *)buf;
+/* Temperature register */
+#define AMG88XX_REG_T01L       0x80
 
-       ret = i2c_transfer(client->adapter, msg, 2);
-
-       return (ret == 2) ? 0 : -EIO;
+static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
+{
+       return regmap_bulk_read(data->regmap, AMG88XX_REG_T01L, buf,
+                               data->chip->buffer_size);
 }
 
 #if IS_ENABLED(CONFIG_HWMON)
@@ -133,12 +132,15 @@ static int amg88xx_read(struct device *dev, enum 
hwmon_sensor_types type,
                        u32 attr, int channel, long *val)
 {
        struct video_i2c_data *data = dev_get_drvdata(dev);
-       struct i2c_client *client = data->client;
-       int tmp = i2c_smbus_read_word_data(client, 0x0e);
+       __le16 buf;
+       int tmp;
 
-       if (tmp < 0)
+       tmp = regmap_bulk_read(data->regmap, AMG88XX_REG_TTHL, &buf, 2);
+       if (tmp)
                return tmp;
 
+       tmp = le16_to_cpu(buf);
+
        /*
         * Check for sign bit, this isn't a two's complement value but an
         * absolute temperature that needs to be inverted in the case of being
@@ -164,8 +166,9 @@ static const struct hwmon_chip_info amg88xx_chip_info = {
 
 static int amg88xx_hwmon_init(struct video_i2c_data *data)
 {
-       void *hwmon = devm_hwmon_device_register_with_info(&data->client->dev,
-                               "amg88xx", data, &amg88xx_chip_info, NULL);
+       struct device *dev = regmap_get_device(data->regmap);
+       void *hwmon = devm_hwmon_device_register_with_info(dev, "amg88xx", data,
+                                               &amg88xx_chip_info, NULL);
 
        return PTR_ERR_OR_ZERO(hwmon);
 }
@@ -182,6 +185,7 @@ static const struct video_i2c_chip video_i2c_chip[] = {
                .max_fps        = 10,
                .buffer_size    = 128,
                .bpp            = 16,
+               .regmap_config  = &amg88xx_regmap_config,
                .xfer           = &amg88xx_xfer,
                .hwmon_init     = amg88xx_hwmon_init,
        },
@@ -350,7 +354,8 @@ static int video_i2c_querycap(struct file *file, void  
*priv,
                                struct v4l2_capability *vcap)
 {
        struct video_i2c_data *data = video_drvdata(file);
-       struct i2c_client *client = data->client;
+       struct device *dev = regmap_get_device(data->regmap);
+       struct i2c_client *client = to_i2c_client(dev);
 
        strlcpy(vcap->driver, data->v4l2_dev.name, sizeof(vcap->driver));
        strlcpy(vcap->card, data->vdev.name, sizeof(vcap->card));
@@ -515,6 +520,7 @@ static void video_i2c_release(struct video_device *vdev)
        v4l2_device_unregister(&data->v4l2_dev);
        mutex_destroy(&data->lock);
        mutex_destroy(&data->queue_lock);
+       regmap_exit(data->regmap);
        kfree(data);
 }
 
@@ -537,13 +543,18 @@ static int video_i2c_probe(struct i2c_client *client,
        else
                goto error_free_device;
 
-       data->client = client;
+       data->regmap = regmap_init_i2c(client, data->chip->regmap_config);
+       if (IS_ERR(data->regmap)) {
+               ret = PTR_ERR(data->regmap);
+               goto error_free_device;
+       }
+
        v4l2_dev = &data->v4l2_dev;
        strlcpy(v4l2_dev->name, VIDEO_I2C_DRIVER, sizeof(v4l2_dev->name));
 
        ret = v4l2_device_register(&client->dev, v4l2_dev);
        if (ret < 0)
-               goto error_free_device;
+               goto error_regmap_exit;
 
        mutex_init(&data->lock);
        mutex_init(&data->queue_lock);
@@ -602,6 +613,9 @@ static int video_i2c_probe(struct i2c_client *client,
        mutex_destroy(&data->lock);
        mutex_destroy(&data->queue_lock);
 
+error_regmap_exit:
+       regmap_exit(data->regmap);
+
 error_free_device:
        kfree(data);
 
-- 
2.7.4

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