Hi Albert
On Thu, 7 Feb 2013, Albert Wang wrote:
> From: Libin Yang <lbyang@xxxxxxxxxxx>
>
> This patch adds the clock tree support for marvell-ccic.
>
> Signed-off-by: Libin Yang <lbyang@xxxxxxxxxxx>
> Signed-off-by: Albert Wang <twang13@xxxxxxxxxxx>
> Acked-by: Jonathan Corbet <corbet@xxxxxxx>
> ---
> drivers/media/platform/marvell-ccic/mcam-core.h | 4 ++
> drivers/media/platform/marvell-ccic/mmp-driver.c | 47 ++++++++++++++++++++++
> 2 files changed, 51 insertions(+)
>
> diff --git a/drivers/media/platform/marvell-ccic/mcam-core.h b/drivers/media/platform/marvell-ccic/mcam-core.h
> index f73a801..2b2dc06 100755
> --- a/drivers/media/platform/marvell-ccic/mcam-core.h
> +++ b/drivers/media/platform/marvell-ccic/mcam-core.h
> @@ -82,6 +82,8 @@ struct mcam_frame_state {
> unsigned int delivered;
> };
>
> +#define NR_MCAM_CLK 3
> +
> /*
> * A description of one of our devices.
> * Locking: controlled by s_mutex. Certain fields, however, require
> @@ -109,6 +111,8 @@ struct mcam_camera {
> int lane; /* lane number */
>
> struct clk *pll1;
> + /* clock tree support */
> + struct clk *clk[NR_MCAM_CLK];
>
> /*
> * 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 7ab01e9..2fe0324 100755
> --- a/drivers/media/platform/marvell-ccic/mmp-driver.c
> +++ b/drivers/media/platform/marvell-ccic/mmp-driver.c
> @@ -35,6 +35,8 @@ MODULE_ALIAS("platform:mmp-camera");
> MODULE_AUTHOR("Jonathan Corbet <corbet@xxxxxxx>");
> MODULE_LICENSE("GPL");
>
> +static char *mcam_clks[] = {"CCICAXICLK", "CCICFUNCLK", "CCICPHYCLK"};
> +
It's good, you are using fixed clock names now!
> struct mmp_camera {
> void *power_regs;
> struct platform_device *pdev;
> @@ -104,6 +106,26 @@ 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_enable(struct mcam_camera *mcam)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < NR_MCAM_CLK; i++) {
> + if (mcam->clk[i])
> + clk_enable(mcam->clk[i]);
I think it's generally considered a better option to use
clk_prepare_enable() and clk_disable_unprepare() instead of just
clk_enable() and clk_disable().
> + }
> +}
> +
> +static void mcam_clk_disable(struct mcam_camera *mcam)
> +{
> + int i;
> +
> + for (i = NR_MCAM_CLK - 1; i >= 0; i--) {
> + if (mcam->clk[i])
> + clk_disable(mcam->clk[i]);
> + }
> +}
> +
> /*
> * Power control.
> */
> @@ -134,6 +156,8 @@ 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_enable(mcam);
> }
>
> static void mmpcam_power_down(struct mcam_camera *mcam)
> @@ -151,6 +175,8 @@ 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_disable(mcam);
> }
>
> /*
> @@ -263,6 +289,23 @@ static irqreturn_t mmpcam_irq(int irq, void *data)
> return IRQ_RETVAL(handled);
> }
>
> +static int mcam_init_clk(struct mcam_camera *mcam,
> + struct mmp_camera_platform_data *pdata)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < NR_MCAM_CLK; i++) {
> + if (mcam_clks[i] != NULL) {
> + mcam->clk[i] = devm_clk_get(mcam->dev, mcam_clks[i]);
> + if (IS_ERR(mcam->clk[i])) {
> + dev_err(mcam->dev, "Could not get clk: %s\n",
> + mcam_clks[i]);
> + return PTR_ERR(mcam->clk[i]);
> + }
> + }
> + }
> + return 0;
> +}
>
> static int mmpcam_probe(struct platform_device *pdev)
> {
> @@ -331,6 +374,10 @@ static int mmpcam_probe(struct platform_device *pdev)
> ret = -ENODEV;
> goto out_unmap1;
> }
> +
> + ret = mcam_init_clk(mcam, pdata);
> + if (ret)
> + goto out_unmap2;
Now, I'm confused again: doesn't this mean, that all existing users of
this driver will fail?
> /*
> * Find the i2c adapter. This assumes, of course, that the
> * i2c bus is already up and functioning.
> --
> 1.7.9.5
>
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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