Re: [PATCH v7 07/11] media: i2c: ov772x: Support frame interval handling

Laurent Pinchart
2018-01-29T11:01:01Z

Hi Jacopo,

Thank you for the patch.

On Friday, 26 January 2018 15:55:26 EET Jacopo Mondi wrote:
> Add support to ov772x driver for frame intervals handling and enumeration.
> Tested with 10MHz and 24MHz input clock at VGA and QVGA resolutions for
> 10, 15 and 30 frame per second rates.
>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> ---
> drivers/media/i2c/ov772x.c | 315 +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 310 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/media/i2c/ov772x.c b/drivers/media/i2c/ov772x.c
> index 912b1b9..6d46748 100644
> --- a/drivers/media/i2c/ov772x.c
> +++ b/drivers/media/i2c/ov772x.c
> @@ -250,6 +250,7 @@
> #define AEC_1p2 0x10 /* 01: 1/2 window */
> #define AEC_1p4 0x20 /* 10: 1/4 window */
> #define AEC_2p3 0x30 /* 11: Low 2/3 window */
> +#define COM4_RESERVED 0x01 /* Reserved value */

I'd write "Reserved bits", "Reserved value" makes it sound like it's the value
of the full register.

> /* COM5 */
> #define AFR_ON_OFF 0x80 /* Auto frame rate control ON/OFF selection
*/
> @@ -267,6 +268,19 @@
> /* AEC max step control */
> #define AEC_NO_LIMIT 0x01 /* 0 : AEC incease step has limit */
> /* 1 : No limit to AEC increase step */
> +/* CLKRC */
> + /* Input clock divider register */
> +#define CLKRC_RESERVED 0x80 /* Reserved value */
> +#define CLKRC_BYPASS 0x40 /* Bypass input clock divider */
> +#define CLKRC_DIV2 0x01 /* Divide input clock by 2 */
> +#define CLKRC_DIV3 0x02 /* Divide input clock by 3 */
> +#define CLKRC_DIV4 0x03 /* Divide input clock by 4 */
> +#define CLKRC_DIV5 0x04 /* Divide input clock by 5 */
> +#define CLKRC_DIV6 0x05 /* Divide input clock by 6 */
> +#define CLKRC_DIV8 0x07 /* Divide input clock by 8 */
> +#define CLKRC_DIV10 0x09 /* Divide input clock by 10 */
> +#define CLKRC_DIV16 0x0f /* Divide input clock by 16 */
> +#define CLKRC_DIV20 0x13 /* Divide input clock by 20 */

How about just

#define CLKRC_DIV(n) ((n) - 1)

> /* COM7 */
> /* SCCB Register Reset */
> @@ -373,6 +387,12 @@
> #define VERSION(pid, ver) ((pid<<8)|(ver&0xFF))
>
> /*
> + * Input clock frequencies
> + */
> +enum { OV772X_FIN_10MHz, OV772X_FIN_24MHz, OV772X_FIN_48MHz, OV772X_FIN_N,
> };
> +static unsigned int ov772x_fin_vals[] = { 10000000, 24000000, 48000000
> };
> +
> +/*
> * struct
> */
>
> @@ -391,6 +411,16 @@ struct ov772x_win_size {
> struct v4l2_rect rect;
> };
>
> +struct ov772x_pclk_config {
> + u8 com4;
> + u8 clkrc;
> +};
> +
> +struct ov772x_frame_rate {
> + unsigned int fps;
> + const struct ov772x_pclk_config pclk[OV772X_FIN_N];
> +};
> +
> struct ov772x_priv {
> struct v4l2_subdev subdev;
> struct v4l2_ctrl_handler hdl;
> @@ -404,6 +434,7 @@ struct ov772x_priv {
> unsigned short flag_hflip:1;
> /* band_filter = COM8[5] ? 256 - BDBASE : 0 */
> unsigned short band_filter;
> + unsigned int fps;
> };
>
> /*
> @@ -508,6 +539,154 @@ static const struct ov772x_win_size ov772x_win_sizes[]
> = { };
>
> /*
> + * frame rate settings lists
> + */
> +unsigned int ov772x_frame_intervals[] = {10, 15, 30, 60};
> +#define OV772X_N_FRAME_INTERVALS ARRAY_SIZE(ov772x_frame_intervals)
> +
> +static const struct ov772x_frame_rate vga_frame_rates[] = {
> + { /* PCLK = 7,5 MHz */
> + .fps = 10,
> + .pclk = {
> + [OV772X_FIN_10MHz] = {
> + .com4 = PLL_6x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV8 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_24MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_DIV3 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_48MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_DIV6 | CLKRC_RESERVED,
> + },
> + },
> + },
> + { /* PCLK = 12 MHz */
> + .fps = 15,
> + .pclk = {
> + [OV772X_FIN_10MHz] = {
> + .com4 = PLL_4x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV3 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_24MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_DIV2 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_48MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_DIV4 | CLKRC_RESERVED,
> + },
> + },
> + },
> + { /* PCLK = 24 MHz */
> + .fps = 30,
> + .pclk = {
> + [OV772X_FIN_10MHz] = {
> + .com4 = PLL_8x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV3 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_24MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_BYPASS | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_48MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_DIV2 | CLKRC_RESERVED,
> + },
> + },
> + },
> + { /* PCLK = 48 MHz */
> + .fps = 60,
> + .pclk = {
> + [OV772X_FIN_10MHz] = {
> + .com4 = PLL_8x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV2 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_24MHz] = {
> + .com4 = PLL_4x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV2 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_48MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_BYPASS | CLKRC_RESERVED,
> + },
> + },
> + },
> +};
> +
> +static const struct ov772x_frame_rate qvga_frame_rates[] = {
> + { /* PCLK = 3,2 MHz */
> + .fps = 10,
> + .pclk = {
> + [OV772X_FIN_10MHz] = {
> + .com4 = PLL_6x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV16 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_24MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_DIV8 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_48MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_DIV16 | CLKRC_RESERVED,
> + },
> + },
> + },
> + { /* PCLK = 4,8 MHz */
> + .fps = 15,
> + .pclk = {
> + [OV772X_FIN_10MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_DIV2 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_24MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_DIV5 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_48MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_DIV10 | CLKRC_RESERVED,
> + },
> + },
> + },
> + { /* PCLK = 9,6 MHz */
> + .fps = 30,
> + .pclk = {
> + [OV772X_FIN_10MHz] = {
> + .com4 = PLL_BYPASS | COM4_RESERVED,
> + .clkrc = CLKRC_BYPASS | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_24MHz] = {
> + .com4 = PLL_4x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV10 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_48MHz] = {
> + .com4 = PLL_4x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV20 | CLKRC_RESERVED,
> + },
> + },
> + },
> + { /* PCLK = 19 MHz */
> + .fps = 60,
> + .pclk = {
> + [OV772X_FIN_10MHz] = {
> + .com4 = PLL_4x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV2 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_24MHz] = {
> + .com4 = PLL_6x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV8 | CLKRC_RESERVED,
> + },
> + [OV772X_FIN_48MHz] = {
> + .com4 = PLL_6x | COM4_RESERVED,
> + .clkrc = CLKRC_DIV16 | CLKRC_RESERVED,
> + },
> + },
> + },
> +};
> +
> +/*
> * general function
> */

I'm afraid I'll have to ask the obvious: could we replace this table with
dynamic computation ? You might be able to reuse the (probably badly named)
aptina-pll library from drivers/media/i2c/

> @@ -574,6 +753,102 @@ static int ov772x_s_stream(struct v4l2_subdev *sd, int
> enable) return 0;
> }
>
> +/*
> + * Approximate input clock frequency to the closes possible one used to
> + * calculate pixel clock settings.
> + */
> +static int ov772x_get_fin(struct ov772x_priv *priv)
> +{
> + unsigned int clk_rate = clk_get_rate(priv->clk);
> + unsigned int rate_prev = ~0L;
> + unsigned int rate;
> + unsigned int idx;
> + unsigned int i;
> +
> + for (i = 0, idx = 0; i < OV772X_FIN_N; i++) {
> + rate = abs(ov772x_fin_vals[i] - clk_rate);
> + if (rate < rate_prev) {
> + rate_prev = rate;
> + idx = i;
> + }
> + }
> +
> + return idx;
> +}
> +
> +static int ov772x_set_frame_rate(struct ov772x_priv *priv,
> + struct v4l2_fract *tpf, unsigned int fin,
> + const struct ov772x_win_size *win)
> +{
> + struct i2c_client *client = v4l2_get_subdevdata(&priv->subdev);
> + unsigned int fps = tpf->denominator / tpf->numerator;
> + const struct ov772x_frame_rate *frate;
> + const struct ov772x_pclk_config *pclk;
> + unsigned int rate_prev = ~0L;
> + unsigned int rate;
> + unsigned int idx;
> + unsigned int i;
> + int ret;
> +
> + if (win->rect.width = VGA_WIDTH &&
> + win->rect.height = VGA_HEIGHT)
> + frate = vga_frame_rates;
> + else if (win->rect.width = QVGA_WIDTH &&
> + win->rect.height = QVGA_HEIGHT)
> + frate = qvga_frame_rates;
> + else
> + return -EINVAL;
> +
> + /* Approximate to the closest possible frame interval. */
> + for (i = 0, idx = 0; i < OV772X_N_FRAME_INTERVALS; i++) {
> + rate = abs(fps - frate[i].fps);
> + if (rate < rate_prev) {
> + idx = i;
> + rate_prev = rate;
> + }
> + }
> +
> + pclk = &frate[idx].pclk[fin];
> +
> + ret = ov772x_write(client, COM4, pclk->com4);
> + if (ret < 0)
> + return ret;
> +
> + ret = ov772x_write(client, CLKRC, pclk->clkrc);
> + if (ret < 0)
> + return ret;
> +
> + tpf->numerator = 1;
> + tpf->denominator = frate[idx].fps;
> + priv->fps = tpf->denominator;
> +
> + return 0;
> +}
> +
> +static int ov772x_g_frame_interval(struct v4l2_subdev *sd,
> + struct v4l2_subdev_frame_interval *ival)
> +{
> + struct ov772x_priv *priv = to_ov772x(sd);
> + struct v4l2_fract *tpf = &ival->interval;
> +
> + memset(ival->reserved, 0, sizeof(ival->reserved));
> + tpf->numerator = 1;
> + tpf->denominator = priv->fps;
> +
> + return 0;
> +}
> +
> +static int ov772x_s_frame_interval(struct v4l2_subdev *sd,
> + struct v4l2_subdev_frame_interval *ival)
> +{
> + struct ov772x_priv *priv = to_ov772x(sd);
> + struct v4l2_fract *tpf = &ival->interval;
> +
> + memset(ival->reserved, 0, sizeof(ival->reserved));
> +
> + return ov772x_set_frame_rate(priv, tpf,
> + ov772x_get_fin(priv), priv->win);
> +}
> static int ov772x_s_ctrl(struct v4l2_ctrl *ctrl)
> {
> struct ov772x_priv *priv = container_of(ctrl->handler,
> @@ -757,6 +1032,7 @@ static int ov772x_set_params(struct ov772x_priv *priv,
> const struct ov772x_win_size *win)
> {
> struct i2c_client *client = v4l2_get_subdevdata(&priv->subdev);
> + struct v4l2_fract tpf;
> int ret;
> u8 val;
>
> @@ -885,6 +1161,13 @@ static int ov772x_set_params(struct ov772x_priv *priv,
> if (ret < 0)
> goto ov772x_set_fmt_error;
>
> + /* COM4, CLKRC: Set pixel clock and framerate. */
> + tpf.numerator = 1;
> + tpf.denominator = priv->fps;
> + ret = ov772x_set_frame_rate(priv, &tpf, ov772x_get_fin(priv), win);
> + if (ret < 0)
> + goto ov772x_set_fmt_error;
> +
> /*
> * set COM8
> */
> @@ -1040,6 +1323,24 @@ static const struct v4l2_subdev_core_ops
> ov772x_subdev_core_ops = { .s_power = ov772x_s_power,
> };
>
> +static int ov772x_enum_frame_interval(struct v4l2_subdev *sd,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_frame_interval_enum *fie)
> +{
> + if (fie->pad || fie->index >= OV772X_N_FRAME_INTERVALS)
> + return -EINVAL;
> +
> + if (fie->width != VGA_WIDTH && fie->width != QVGA_WIDTH)
> + return -EINVAL;
> + if (fie->height != VGA_HEIGHT && fie->height != QVGA_HEIGHT)
> + return -EINVAL;
> +
> + fie->interval.numerator = 1;
> + fie->interval.denominator = ov772x_frame_intervals[fie->index];
> +
> + return 0;
> +}
> +
> static int ov772x_enum_mbus_code(struct v4l2_subdev *sd,
> struct v4l2_subdev_pad_config *cfg,
> struct v4l2_subdev_mbus_code_enum *code)
> @@ -1052,14 +1353,17 @@ static int ov772x_enum_mbus_code(struct v4l2_subdev
> *sd, }
>
> static const struct v4l2_subdev_video_ops ov772x_subdev_video_ops = {
> - .s_stream = ov772x_s_stream,
> + .s_stream = ov772x_s_stream,
> + .s_frame_interval = ov772x_s_frame_interval,
> + .g_frame_interval = ov772x_g_frame_interval,
> };
>
> static const struct v4l2_subdev_pad_ops ov772x_subdev_pad_ops = {
> - .enum_mbus_code = ov772x_enum_mbus_code,
> - .get_selection = ov772x_get_selection,
> - .get_fmt = ov772x_get_fmt,
> - .set_fmt = ov772x_set_fmt,
> + .enum_frame_interval = ov772x_enum_frame_interval,
> + .enum_mbus_code = ov772x_enum_mbus_code,
> + .get_selection = ov772x_get_selection,
> + .get_fmt = ov772x_get_fmt,
> + .set_fmt = ov772x_set_fmt,
> };
>
> static const struct v4l2_subdev_ops ov772x_subdev_ops = {
> @@ -1131,6 +1435,7 @@ static int ov772x_probe(struct i2c_client *client,
>
> priv->cfmt = &ov772x_cfmts[0];
> priv->win = &ov772x_win_sizes[0];
> + priv->fps = 15;
>
> ret = v4l2_async_register_subdev(&priv->subdev);
> if (ret)

--
Regards,

Laurent Pinchart