Re: [PATCH v2 2/4] drm/msm: dsi: Use OPP API to set clk/perf state

[Rajendra Nayak]

On 7/6/2020 9:40 PM, Matthias Kaehlcke wrote:
> On Thu, Jul 02, 2020 at 04:39:09PM +0530, Rajendra Nayak wrote:
> > On SDM845 and SC7180 DSI needs to express a performance state
> > requirement on a power domain depending on the clock rates.
> > Use OPP table from DT to register with OPP framework and use
> > dev_pm_opp_set_rate() to set the clk/perf state.
> >
> > dev_pm_opp_set_rate() is designed to be equivalent to clk_set_rate()
> > for devices without an OPP table, hence the change works fine
> > on devices/platforms which only need to set a clock rate.
> >
> > Signed-off-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/msm/dsi/dsi_host.c | 26 ++++++++++++++++++++++++--
> >   1 file changed, 24 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > index 11ae5b8..09e16b8 100644
> > --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> > +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > @@ -14,6 +14,7 @@
> >   #include <linux/of_graph.h>
> >   #include <linux/of_irq.h>
> >   #include <linux/pinctrl/consumer.h>
> > +#include <linux/pm_opp.h>
> >   #include <linux/regmap.h>
> >   #include <linux/regulator/consumer.h>
> >   #include <linux/spinlock.h>
> > @@ -111,6 +112,9 @@ struct msm_dsi_host {
> >   	struct clk *pixel_clk_src;
> >   	struct clk *byte_intf_clk;
> >   
> > +	struct opp_table *opp_table;
> > +	bool has_opp_table;
> > +
> >   	u32 byte_clk_rate;
> >   	u32 pixel_clk_rate;
> >   	u32 esc_clk_rate;
> > @@ -512,9 +516,10 @@ int dsi_link_clk_set_rate_6g(struct msm_dsi_host *msm_host)
> >   	DBG("Set clk rates: pclk=%d, byteclk=%d",
> >   		msm_host->mode->clock, msm_host->byte_clk_rate);
> >   
> > -	ret = clk_set_rate(msm_host->byte_clk, msm_host->byte_clk_rate);
> > +	ret = dev_pm_opp_set_rate(&msm_host->pdev->dev,
> > +				  msm_host->byte_clk_rate);
> >   	if (ret) {
> > -		pr_err("%s: Failed to set rate byte clk, %d\n", __func__, ret);
> > +		pr_err("%s: dev_pm_opp_set_rate failed %d\n", __func__, ret);
> >   		return ret;
> >   	}
> >   
> > @@ -658,6 +663,8 @@ int dsi_link_clk_enable_v2(struct msm_dsi_host *msm_host)
> >   
> >   void dsi_link_clk_disable_6g(struct msm_dsi_host *msm_host)
> >   {
> > +	/* Drop the performance state vote */
> > +	dev_pm_opp_set_rate(&msm_host->pdev->dev, 0);
> >   	clk_disable_unprepare(msm_host->esc_clk);
> >   	clk_disable_unprepare(msm_host->pixel_clk);
> >   	if (msm_host->byte_intf_clk)
> > @@ -1879,6 +1886,18 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
> >   		goto fail;
> >   	}
> >   
> > +	msm_host->opp_table = dev_pm_opp_set_clkname(&pdev->dev, "byte");
> > +	if (IS_ERR(msm_host->opp_table))
> > +		return PTR_ERR(msm_host->opp_table);
> > +	/* OPP table is optional */
> > +	ret = dev_pm_opp_of_add_table(&pdev->dev);
> > +	if (!ret) {
> > +		msm_host->has_opp_table = true;
> > +	} else if (ret != -ENODEV) {
> > +		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
>
>    		dev_pm_opp_put_clkname(msm_host->opp_table);
>
> > +		return ret;
> > +	}
>
> With the missing _put_clkname() fixed:

Thanks, I'll fix and resend.

> Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>

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