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path: root/drivers/media/i2c/mt9p031.c
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Diffstat (limited to 'drivers/media/i2c/mt9p031.c')
-rw-r--r--drivers/media/i2c/mt9p031.c49
1 files changed, 45 insertions, 4 deletions
diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c
index 192c4aad05d..33daace8129 100644
--- a/drivers/media/i2c/mt9p031.c
+++ b/drivers/media/i2c/mt9p031.c
@@ -78,6 +78,9 @@
#define MT9P031_PLL_CONFIG_1 0x11
#define MT9P031_PLL_CONFIG_2 0x12
#define MT9P031_PIXEL_CLOCK_CONTROL 0x0a
+#define MT9P031_PIXEL_CLOCK_INVERT (1 << 15)
+#define MT9P031_PIXEL_CLOCK_SHIFT(n) ((n) << 8)
+#define MT9P031_PIXEL_CLOCK_DIVIDE(n) ((n) << 0)
#define MT9P031_FRAME_RESTART 0x0b
#define MT9P031_SHUTTER_DELAY 0x0c
#define MT9P031_RST 0x0d
@@ -130,6 +133,8 @@ struct mt9p031 {
enum mt9p031_model model;
struct aptina_pll pll;
+ unsigned int clk_div;
+ bool use_pll;
int reset;
struct v4l2_ctrl_handler ctrls;
@@ -198,6 +203,11 @@ static int mt9p031_reset(struct mt9p031 *mt9p031)
if (ret < 0)
return ret;
+ ret = mt9p031_write(client, MT9P031_PIXEL_CLOCK_CONTROL,
+ MT9P031_PIXEL_CLOCK_DIVIDE(mt9p031->clk_div));
+ if (ret < 0)
+ return ret;
+
return mt9p031_set_output_control(mt9p031, MT9P031_OUTPUT_CONTROL_CEN,
0);
}
@@ -222,15 +232,34 @@ static int mt9p031_clk_setup(struct mt9p031 *mt9p031)
struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
struct mt9p031_platform_data *pdata = mt9p031->pdata;
+ int ret;
mt9p031->clk = devm_clk_get(&client->dev, NULL);
if (IS_ERR(mt9p031->clk))
return PTR_ERR(mt9p031->clk);
- clk_set_rate(mt9p031->clk, pdata->ext_freq);
+ ret = clk_set_rate(mt9p031->clk, pdata->ext_freq);
+ if (ret < 0)
+ return ret;
+
+ /* If the external clock frequency is out of bounds for the PLL use the
+ * pixel clock divider only and disable the PLL.
+ */
+ if (pdata->ext_freq > limits.ext_clock_max) {
+ unsigned int div;
+
+ div = DIV_ROUND_UP(pdata->ext_freq, pdata->target_freq);
+ div = roundup_pow_of_two(div) / 2;
+
+ mt9p031->clk_div = max_t(unsigned int, div, 64);
+ mt9p031->use_pll = false;
+
+ return 0;
+ }
mt9p031->pll.ext_clock = pdata->ext_freq;
mt9p031->pll.pix_clock = pdata->target_freq;
+ mt9p031->use_pll = true;
return aptina_pll_calculate(&client->dev, &limits, &mt9p031->pll);
}
@@ -240,6 +269,9 @@ static int mt9p031_pll_enable(struct mt9p031 *mt9p031)
struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
int ret;
+ if (!mt9p031->use_pll)
+ return 0;
+
ret = mt9p031_write(client, MT9P031_PLL_CONTROL,
MT9P031_PLL_CONTROL_PWRON);
if (ret < 0)
@@ -265,6 +297,9 @@ static inline int mt9p031_pll_disable(struct mt9p031 *mt9p031)
{
struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
+ if (!mt9p031->use_pll)
+ return 0;
+
return mt9p031_write(client, MT9P031_PLL_CONTROL,
MT9P031_PLL_CONTROL_PWROFF);
}
@@ -285,9 +320,15 @@ static int mt9p031_power_on(struct mt9p031 *mt9p031)
if (ret < 0)
return ret;
- /* Emable clock */
- if (mt9p031->clk)
- clk_prepare_enable(mt9p031->clk);
+ /* Enable clock */
+ if (mt9p031->clk) {
+ ret = clk_prepare_enable(mt9p031->clk);
+ if (ret) {
+ regulator_bulk_disable(ARRAY_SIZE(mt9p031->regulators),
+ mt9p031->regulators);
+ return ret;
+ }
+ }
/* Now RESET_BAR must be high */
if (gpio_is_valid(mt9p031->reset)) {