media: mt9m001: introduce multi_reg_write()

Introduce multi_reg_write() to write multiple registers to the device and
use it where possible.

Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/i2c/mt9m001.c b/drivers/media/i2c/mt9m001.c
index 3864d884b8c3a6146628a700099c67fe0e463994..7ba11a8da037a574ea9db66ebc53559f61d4d7f4 100644 (file)
--- a/drivers/media/i2c/mt9m001.c
+++ b/drivers/media/i2c/mt9m001.c
@@ -47,6 +47,8 @@
 #define MT9M001_MIN_HEIGHT             32
 #define MT9M001_COLUMN_SKIP            20
 #define MT9M001_ROW_SKIP               12
+#define MT9M001_DEFAULT_HBLANK         9
+#define MT9M001_DEFAULT_VBLANK         25
 
 /* MT9M001 has only one fixed colorspace per pixelcode */
 struct mt9m001_datafmt {
@@ -137,25 +139,65 @@ static int reg_clear(struct i2c_client *client, const u8 reg,
        return reg_write(client, reg, ret & ~data);
 }
 
+struct mt9m001_reg {
+       u8 reg;
+       u16 data;
+};
+
+static int multi_reg_write(struct i2c_client *client,
+                          const struct mt9m001_reg *regs, int num)
+{
+       int i;
+
+       for (i = 0; i < num; i++) {
+               int ret = reg_write(client, regs[i].reg, regs[i].data);
+
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
+}
+
 static int mt9m001_init(struct i2c_client *client)
 {
-       int ret;
+       const struct mt9m001_reg init_regs[] = {
+               /*
+                * Issue a soft reset. This returns all registers to their
+                * default values.
+                */
+               { MT9M001_RESET, 1 },
+               { MT9M001_RESET, 0 },
+               /* Disable chip, synchronous option update */
+               { MT9M001_OUTPUT_CONTROL, 0 }
+       };
 
        dev_dbg(&client->dev, "%s\n", __func__);
 
-       /*
-        * We don't know, whether platform provides reset, issue a soft reset
-        * too. This returns all registers to their default values.
-        */
-       ret = reg_write(client, MT9M001_RESET, 1);
-       if (!ret)
-               ret = reg_write(client, MT9M001_RESET, 0);
+       return multi_reg_write(client, init_regs, ARRAY_SIZE(init_regs));
+}
 
-       /* Disable chip, synchronous option update */
-       if (!ret)
-               ret = reg_write(client, MT9M001_OUTPUT_CONTROL, 0);
+static int mt9m001_apply_selection(struct v4l2_subdev *sd,
+                                   struct v4l2_rect *rect)
+{
+       struct i2c_client *client = v4l2_get_subdevdata(sd);
+       struct mt9m001 *mt9m001 = to_mt9m001(client);
+       const struct mt9m001_reg regs[] = {
+               /* Blanking and start values - default... */
+               { MT9M001_HORIZONTAL_BLANKING, MT9M001_DEFAULT_HBLANK },
+               { MT9M001_VERTICAL_BLANKING, MT9M001_DEFAULT_VBLANK },
+               /*
+                * The caller provides a supported format, as verified per
+                * call to .set_fmt(FORMAT_TRY).
+                */
+               { MT9M001_COLUMN_START, rect->left },
+               { MT9M001_ROW_START, rect->top },
+               { MT9M001_WINDOW_WIDTH, rect->width - 1 },
+               { MT9M001_WINDOW_HEIGHT,
+                       rect->height + mt9m001->y_skip_top - 1 },
+       };
 
-       return ret;
+       return multi_reg_write(client, regs, ARRAY_SIZE(regs));
 }
 
 static int mt9m001_s_stream(struct v4l2_subdev *sd, int enable)
@@ -175,7 +217,6 @@ static int mt9m001_set_selection(struct v4l2_subdev *sd,
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9m001 *mt9m001 = to_mt9m001(client);
        struct v4l2_rect rect = sel->r;
-       const u16 hblank = 9, vblank = 25;
        int ret;
 
        if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE ||
@@ -199,26 +240,11 @@ static int mt9m001_set_selection(struct v4l2_subdev *sd,
        soc_camera_limit_side(&rect.top, &rect.height,
                     MT9M001_ROW_SKIP, MT9M001_MIN_HEIGHT, MT9M001_MAX_HEIGHT);
 
-       mt9m001->total_h = rect.height + mt9m001->y_skip_top + vblank;
+       mt9m001->total_h = rect.height + mt9m001->y_skip_top +
+                          MT9M001_DEFAULT_VBLANK;
 
-       /* Blanking and start values - default... */
-       ret = reg_write(client, MT9M001_HORIZONTAL_BLANKING, hblank);
-       if (!ret)
-               ret = reg_write(client, MT9M001_VERTICAL_BLANKING, vblank);
 
-       /*
-        * The caller provides a supported format, as verified per
-        * call to .set_fmt(FORMAT_TRY).
-        */
-       if (!ret)
-               ret = reg_write(client, MT9M001_COLUMN_START, rect.left);
-       if (!ret)
-               ret = reg_write(client, MT9M001_ROW_START, rect.top);
-       if (!ret)
-               ret = reg_write(client, MT9M001_WINDOW_WIDTH, rect.width - 1);
-       if (!ret)
-               ret = reg_write(client, MT9M001_WINDOW_HEIGHT,
-                               rect.height + mt9m001->y_skip_top - 1);
+       ret = mt9m001_apply_selection(sd, &rect);
        if (!ret && v4l2_ctrl_g_ctrl(mt9m001->autoexposure) == V4L2_EXPOSURE_AUTO)
                ret = reg_write(client, MT9M001_SHUTTER_WIDTH, mt9m001->total_h);