| Message ID | 1613750416-11901-8-git-send-email-abel.vesa@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Rework support for i.MX8MQ interconnect with devfreq | expand |
On 21. 2. 20. 오전 1:00, Abel Vesa wrote: > Seems that, in order to be able to resume from suspend, the dram rate > needs to be the highest one available. Therefore, add the late system > suspend/resume PM ops which set the highest rate on suspend and the > latest one used before suspending on resume. > > Signed-off-by: Abel Vesa <abel.vesa@nxp.com> > --- > drivers/devfreq/imx8m-ddrc.c | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) > > diff --git a/drivers/devfreq/imx8m-ddrc.c b/drivers/devfreq/imx8m-ddrc.c > index 33de83acfd8b..04347dee781b 100644 > --- a/drivers/devfreq/imx8m-ddrc.c > +++ b/drivers/devfreq/imx8m-ddrc.c > @@ -72,6 +72,8 @@ struct imx8m_ddrc { > struct clk *dram_alt; > struct clk *dram_apb; > > + unsigned long suspend_rate; > + unsigned long resume_rate; > int freq_count; > struct imx8m_ddrc_freq freq_table[IMX8M_DDRC_MAX_FREQ_COUNT]; > }; > @@ -271,6 +273,22 @@ static int imx8m_ddrc_target(struct device *dev, unsigned long *freq, u32 flags) > return ret; > } > > +static int imx8m_ddrc_suspend(struct device *dev) > +{ > + struct imx8m_ddrc *priv = dev_get_drvdata(dev); > + > + priv->resume_rate = clk_get_rate(priv->dram_core); > + > + return imx8m_ddrc_target(dev, &priv->suspend_rate, 0); > +} > + > +static int imx8m_ddrc_resume(struct device *dev) > +{ > + struct imx8m_ddrc *priv = dev_get_drvdata(dev); > + > + return imx8m_ddrc_target(dev, &priv->resume_rate, 0); > +} > + > static int imx8m_ddrc_get_cur_freq(struct device *dev, unsigned long *freq) > { > struct imx8m_ddrc *priv = dev_get_drvdata(dev); > @@ -336,6 +354,9 @@ static int imx8m_ddrc_init_freq_info(struct device *dev) > > if (dev_pm_opp_add(dev, freq->rate * 250000, 0)) > return -ENODEV; > + > + if (index == 0) > + priv->suspend_rate = freq->rate * 250000; > } > > return 0; > @@ -412,10 +433,15 @@ static const struct of_device_id imx8m_ddrc_of_match[] = { > }; > MODULE_DEVICE_TABLE(of, imx8m_ddrc_of_match); > > +static const struct dev_pm_ops imx8m_ddrc_pm_ops = { > + SET_LATE_SYSTEM_SLEEP_PM_OPS(imx8m_ddrc_suspend, imx8m_ddrc_resume) > +}; Are there any reason to use suspend_late instead of suspend? Usually, it is enough to change the frequency on normal suspend() step. The devfreq supports the 'opp-suspend' property[1]. If you keep the OPP entries on DT, you simply support your goal with 'opp-suspend'. [1] https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/opp/opp.txt#L156 > + > static struct platform_driver imx8m_ddrc_platdrv = { > .probe = imx8m_ddrc_probe, > .driver = { > .name = "imx8m-ddrc-devfreq", > + .pm = &imx8m_ddrc_pm_ops, > .of_match_table = of_match_ptr(imx8m_ddrc_of_match), > }, > }; >
diff --git a/drivers/devfreq/imx8m-ddrc.c b/drivers/devfreq/imx8m-ddrc.c index 33de83acfd8b..04347dee781b 100644 --- a/drivers/devfreq/imx8m-ddrc.c +++ b/drivers/devfreq/imx8m-ddrc.c @@ -72,6 +72,8 @@ struct imx8m_ddrc { struct clk *dram_alt; struct clk *dram_apb; + unsigned long suspend_rate; + unsigned long resume_rate; int freq_count; struct imx8m_ddrc_freq freq_table[IMX8M_DDRC_MAX_FREQ_COUNT]; }; @@ -271,6 +273,22 @@ static int imx8m_ddrc_target(struct device *dev, unsigned long *freq, u32 flags) return ret; } +static int imx8m_ddrc_suspend(struct device *dev) +{ + struct imx8m_ddrc *priv = dev_get_drvdata(dev); + + priv->resume_rate = clk_get_rate(priv->dram_core); + + return imx8m_ddrc_target(dev, &priv->suspend_rate, 0); +} + +static int imx8m_ddrc_resume(struct device *dev) +{ + struct imx8m_ddrc *priv = dev_get_drvdata(dev); + + return imx8m_ddrc_target(dev, &priv->resume_rate, 0); +} + static int imx8m_ddrc_get_cur_freq(struct device *dev, unsigned long *freq) { struct imx8m_ddrc *priv = dev_get_drvdata(dev); @@ -336,6 +354,9 @@ static int imx8m_ddrc_init_freq_info(struct device *dev) if (dev_pm_opp_add(dev, freq->rate * 250000, 0)) return -ENODEV; + + if (index == 0) + priv->suspend_rate = freq->rate * 250000; } return 0; @@ -412,10 +433,15 @@ static const struct of_device_id imx8m_ddrc_of_match[] = { }; MODULE_DEVICE_TABLE(of, imx8m_ddrc_of_match); +static const struct dev_pm_ops imx8m_ddrc_pm_ops = { + SET_LATE_SYSTEM_SLEEP_PM_OPS(imx8m_ddrc_suspend, imx8m_ddrc_resume) +}; + static struct platform_driver imx8m_ddrc_platdrv = { .probe = imx8m_ddrc_probe, .driver = { .name = "imx8m-ddrc-devfreq", + .pm = &imx8m_ddrc_pm_ops, .of_match_table = of_match_ptr(imx8m_ddrc_of_match), }, };
Seems that, in order to be able to resume from suspend, the dram rate needs to be the highest one available. Therefore, add the late system suspend/resume PM ops which set the highest rate on suspend and the latest one used before suspending on resume. Signed-off-by: Abel Vesa <abel.vesa@nxp.com> --- drivers/devfreq/imx8m-ddrc.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)