On Sat, 15 Dec 2012, Albert Wang wrote:
> From: Libin Yang <lbyang@xxxxxxxxxxx>
>
> This patch adds the clock tree support for marvell-ccic.
>
> Each board may require different clk enabling sequence.
> Developer need add the clk_name in correct sequence in board driver
> to use this feature.
>
> Signed-off-by: Libin Yang <lbyang@xxxxxxxxxxx>
> Signed-off-by: Albert Wang <twang13@xxxxxxxxxxx>
> ---
> drivers/media/platform/marvell-ccic/mcam-core.h | 4 ++
> drivers/media/platform/marvell-ccic/mmp-driver.c | 57 +++++++++++++++++++++-
> include/media/mmp-camera.h | 5 ++
> 3 files changed, 65 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/marvell-ccic/mcam-core.h b/drivers/media/platform/marvell-ccic/mcam-core.h
> index ca63010..86e634e 100755
> --- a/drivers/media/platform/marvell-ccic/mcam-core.h
> +++ b/drivers/media/platform/marvell-ccic/mcam-core.h
> @@ -88,6 +88,7 @@ struct mcam_frame_state {
> * the dev_lock spinlock; they are marked as such by comments.
> * dev_lock is also required for access to device registers.
> */
> +#define NR_MCAM_CLK 4
> struct mcam_camera {
> /*
> * These fields should be set by the platform code prior to
> @@ -109,6 +110,9 @@ struct mcam_camera {
> int lane; /* lane number */
>
> struct clk *pll1;
> + /* clock tree support */
> + struct clk *clk[NR_MCAM_CLK];
> + int clk_num;
>
> /*
> * Callbacks from the core to the platform code.
> diff --git a/drivers/media/platform/marvell-ccic/mmp-driver.c b/drivers/media/platform/marvell-ccic/mmp-driver.c
> index 603fa0a..2c4dce3 100755
> --- a/drivers/media/platform/marvell-ccic/mmp-driver.c
> +++ b/drivers/media/platform/marvell-ccic/mmp-driver.c
> @@ -104,6 +104,23 @@ static struct mmp_camera *mmpcam_find_device(struct platform_device *pdev)
> #define REG_CCIC_DCGCR 0x28 /* CCIC dyn clock gate ctrl reg */
> #define REG_CCIC_CRCR 0x50 /* CCIC clk reset ctrl reg */
>
> +static void mcam_clk_set(struct mcam_camera *mcam, int on)
Personally, I would also make two functions out of this - "on" and "off,"
but that's a matter of taste, perhaps.
> +{
> + unsigned int i;
> +
> + if (on) {
> + for (i = 0; i < mcam->clk_num; i++) {
> + if (mcam->clk[i])
> + clk_enable(mcam->clk[i]);
> + }
> + } else {
> + for (i = mcam->clk_num; i > 0; i--) {
> + if (mcam->clk[i - 1])
> + clk_disable(mcam->clk[i - 1]);
> + }
> + }
> +}
> +
> /*
> * Power control.
> */
> @@ -134,6 +151,8 @@ static void mmpcam_power_up(struct mcam_camera *mcam)
> mdelay(5);
> gpio_set_value(pdata->sensor_reset_gpio, 1); /* reset is active low */
> mdelay(5);
> +
> + mcam_clk_set(mcam, 1);
> }
>
> static void mmpcam_power_down(struct mcam_camera *mcam)
> @@ -151,6 +170,8 @@ static void mmpcam_power_down(struct mcam_camera *mcam)
> pdata = cam->pdev->dev.platform_data;
> gpio_set_value(pdata->sensor_power_gpio, 0);
> gpio_set_value(pdata->sensor_reset_gpio, 0);
> +
> + mcam_clk_set(mcam, 0);
> }
>
> /*
> @@ -202,7 +223,7 @@ void mmpcam_calc_dphy(struct mcam_camera *mcam)
> * pll1 will never be changed, it is a fixed value
> */
>
> - if (IS_ERR(mcam->pll1))
> + if (IS_ERR_OR_NULL(mcam->pll1))
Why are you changing this? If this really were needed, you should do this
already in the previous patch, where you add these lines. But I don't
think this is a good idea, don't think Russell would like this :-) NULL is
a valid clock. Only a negative error is a failure. In fact, if you like,
you could initialise .pll1 to ERR_PTR(-EINVAL) in your previous patch in
mmpcam_probe().
> return;
>
> tx_clk_esc = clk_get_rate(mcam->pll1) / 1000000 / 12;
> @@ -229,6 +250,35 @@ static irqreturn_t mmpcam_irq(int irq, void *data)
> return IRQ_RETVAL(handled);
> }
>
> +static void mcam_init_clk(struct mcam_camera *mcam,
> + struct mmp_camera_platform_data *pdata, int init)
I don't think this "int init" makes sense. Please, remove the parameter
and you actually don't need the de-initialisation, no reason to set
num_clk = 0 before freeing memory.
> +{
> + unsigned int i;
> +
> + if (NR_MCAM_CLK < pdata->clk_num) {
> + dev_err(mcam->dev, "Too many mcam clocks defined\n");
> + mcam->clk_num = 0;
> + return;
> + }
> +
> + if (init) {
> + for (i = 0; i < pdata->clk_num; i++) {
> + if (pdata->clk_name[i] != NULL) {
> + mcam->clk[i] = devm_clk_get(mcam->dev,
> + pdata->clk_name[i]);
Sorry, no. Passing clock names in platform data doesn't look right to me.
Clock names are a property of the consumer device, not of clock supplier.
Also, your platform tells you to get clk_num clocks, you fail to get one
of them, you don't continue trying the rest and just return with no error.
This seems strange, usually a failure to get clocks, that the platform
tells you to get, is fatal.
> + if (IS_ERR(mcam->clk[i])) {
> + dev_err(mcam->dev,
> + "Could not get clk: %s\n",
> + pdata->clk_name[i]);
> + mcam->clk_num = 0;
> + return;
> + }
> + }
> + }
> + mcam->clk_num = pdata->clk_num;
> + } else
> + mcam->clk_num = 0;
> +}
>
> static int mmpcam_probe(struct platform_device *pdev)
> {
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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