Re: [PATCH v7 2/5] media: imx8mq-mipi-csi2: Use devm_clk_bulk_get_all() to fetch clocks

Laurent Pinchart
2025-10-27T00:12:07Z

On Thu, Oct 23, 2025 at 05:19:43PM +0800, Guoniu Zhou wrote:
> From: Guoniu Zhou <guoniu.zhou@nxp.com>
>
> Use devm_clk_bulk_get_all() helper to simplify clock handle code.
>
> No functional changes intended.
>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Guoniu Zhou <guoniu.zhou@nxp.com>
> ---
> drivers/media/platform/nxp/imx8mq-mipi-csi2.c | 52 ++++++++-------------------
> 1 file changed, 15 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/media/platform/nxp/imx8mq-mipi-csi2.c b/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
> index d333ff43539f061b8b9cf88af2cda8c44b3ec2a9..fd202601d401145da8be23df4451f6af660642c5 100644
> --- a/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
> +++ b/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
> @@ -71,21 +71,6 @@ enum {
> ST_SUSPENDED = 4,
> };
>
> -enum imx8mq_mipi_csi_clk {
> - CSI2_CLK_CORE,
> - CSI2_CLK_ESC,
> - CSI2_CLK_UI,
> - CSI2_NUM_CLKS,
> -};
> -
> -static const char * const imx8mq_mipi_csi_clk_id[CSI2_NUM_CLKS] = {
> - [CSI2_CLK_CORE] = "core",
> - [CSI2_CLK_ESC] = "esc",
> - [CSI2_CLK_UI] = "ui",
> -};
> -
> -#define CSI2_NUM_CLKS ARRAY_SIZE(imx8mq_mipi_csi_clk_id)
> -
> struct imx8mq_plat_data {
> int (*enable)(struct csi_state *state, u32 hs_settle);
> void (*disable)(struct csi_state *state);
> @@ -111,7 +96,8 @@ struct csi_state {
> struct device *dev;
> const struct imx8mq_plat_data *pdata;
> void __iomem *regs;
> - struct clk_bulk_data clks[CSI2_NUM_CLKS];
> + struct clk_bulk_data *clks;
> + int num_clks;
> struct reset_control *rst;
> struct regulator *mipi_phy_regulator;
>
> @@ -384,24 +370,16 @@ static void imx8mq_mipi_csi_set_params(struct csi_state *state)
> CSI2RX_SEND_LEVEL);
> }
>
> -static int imx8mq_mipi_csi_clk_enable(struct csi_state *state)
> -{
> - return clk_bulk_prepare_enable(CSI2_NUM_CLKS, state->clks);
> -}
> -
> -static void imx8mq_mipi_csi_clk_disable(struct csi_state *state)
> +static struct clk *find_esc_clk(struct csi_state *state)

This is one of the reasons why I don't like devm_clk_bulk_get_all(). I
won't object to this patch, but I don't like it. At the very lest, you
should look up the clock at probe time and cache it in the
imx8mq_plat_data structure, to avoid looking it up multiple times at
runtime.

> {
> - clk_bulk_disable_unprepare(CSI2_NUM_CLKS, state->clks);
> -}
> -
> -static int imx8mq_mipi_csi_clk_get(struct csi_state *state)
> -{
> - unsigned int i;
> + int i;
>
> - for (i = 0; i < CSI2_NUM_CLKS; i++)
> - state->clks[i].id = imx8mq_mipi_csi_clk_id[i];
> + for (i = 0; i < state->num_clks; i++) {

Make state->num_clks unsigned instead of making i signed.

> + if (!strcmp(state->clks[i].id, "esc"))
> + return state->clks[i].clk;
> + }
>
> - return devm_clk_bulk_get(state->dev, CSI2_NUM_CLKS, state->clks);
> + return NULL;

This needs to become a probe error.

> }
>
> static int imx8mq_mipi_csi_calc_hs_settle(struct csi_state *state,
> @@ -456,7 +434,7 @@ static int imx8mq_mipi_csi_calc_hs_settle(struct csi_state *state,
> * documentation recommends picking a value away from the boundaries.
> * Let's pick the average.
> */
> - esc_clk_rate = clk_get_rate(state->clks[CSI2_CLK_ESC].clk);
> + esc_clk_rate = clk_get_rate(find_esc_clk(state));
> if (!esc_clk_rate) {
> dev_err(state->dev, "Could not get esc clock rate.\n");
> return -EINVAL;
> @@ -783,7 +761,7 @@ static void imx8mq_mipi_csi_pm_suspend(struct device *dev)
>
> if (state->state & ST_POWERED) {
> imx8mq_mipi_csi_stop_stream(state);
> - imx8mq_mipi_csi_clk_disable(state);
> + clk_bulk_disable_unprepare(state->num_clks, state->clks);
> state->state &= ~ST_POWERED;
> }
>
> @@ -801,7 +779,7 @@ static int imx8mq_mipi_csi_pm_resume(struct device *dev)
>
> if (!(state->state & ST_POWERED)) {
> state->state |= ST_POWERED;
> - ret = imx8mq_mipi_csi_clk_enable(state);
> + ret = clk_bulk_prepare_enable(state->num_clks, state->clks);
> }
> if (state->state & ST_STREAMING) {
> sd_state = v4l2_subdev_lock_and_get_active_state(sd);
> @@ -1027,9 +1005,9 @@ static int imx8mq_mipi_csi_probe(struct platform_device *pdev)
> if (IS_ERR(state->regs))
> return PTR_ERR(state->regs);
>
> - ret = imx8mq_mipi_csi_clk_get(state);
> - if (ret < 0)
> - return ret;
> + state->num_clks = devm_clk_bulk_get_all(dev, &state->clks);
> + if (state->num_clks < 0)
> + return dev_err_probe(dev, state->num_clks, "Failed to get clocks\n");
>
> platform_set_drvdata(pdev, &state->sd);
>

--
Regards,

Laurent Pinchart