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[media] mt9p031: Add support for PLL bypass

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When the input clock frequency is out of bounds for the PLL, bypass the
PLL and just divide the input clock to achieve the requested output
frequency.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
This commit is contained in:
Laurent Pinchart 2014-02-09 17:31:47 -03:00 committed by Mauro Carvalho Chehab
parent e8e45593c9
commit a970449e40
1 changed files with 32 additions and 0 deletions
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32
drivers/media/i2c/mt9p031.c
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@ -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);
}
@ -229,8 +239,24 @@ static int mt9p031_clk_setup(struct mt9p031 *mt9p031)
clk_set_rate(mt9p031->clk, pdata->ext_freq);
/* 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 +266,9 @@ 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 +294,9 @@ 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);
}