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

Laurent Pinchart
2025-11-11T17:28:31Z

On Tue, Nov 04, 2025 at 07:47:43AM +0000, G.N. Zhou (OSS) wrote:
> On Monday, October 27, 2025 8:12 AM, Laurent Pinchart wrote:
> > 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..fd202601d401145da8be23df4451
> > > f6af660642c5 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.
>
> Ok, but could we cache the clock in the csi_state structure? Because the imx8mq_plat_data
> structure instance is const.

Yes sorry that's what I meant.

> > > {
> > > - 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.
>
> Got it, will update in next version.
>
> > > }
> > >
> > > 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