| Message ID | 1588507469-31889-1-git-send-email-rnayak@codeaurora.org |
|---|---|
| Headers | show |
| Series | DVFS for IO devices on sdm845 and sc7180 | expand |
Hi Rajendra, On Sun, May 03, 2020 at 05:34:29PM +0530, Rajendra Nayak wrote: > QSPI needs to vote on a performance state of a power domain depending on > the clock rate. Add support for it by specifying the perf state/clock rate > as an OPP table in device tree. > > Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org> > Cc: Mark Brown <broonie@kernel.org> > Cc: Alok Chauhan <alokc@codeaurora.org> > Cc: Akash Asthana <akashast@codeaurora.org> > Cc: linux-spi@vger.kernel.org > --- > drivers/spi/spi-qcom-qspi.c | 29 ++++++++++++++++++++++++++++- > 1 file changed, 28 insertions(+), 1 deletion(-) > > diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c > index 3c4f83b..eb53c00 100644 > --- a/drivers/spi/spi-qcom-qspi.c > +++ b/drivers/spi/spi-qcom-qspi.c > @@ -8,6 +8,7 @@ > #include <linux/of.h> > #include <linux/of_platform.h> > #include <linux/pm_runtime.h> > +#include <linux/pm_opp.h> > #include <linux/spi/spi.h> > #include <linux/spi/spi-mem.h> > > @@ -139,6 +140,8 @@ struct qcom_qspi { > struct device *dev; > struct clk_bulk_data *clks; > struct qspi_xfer xfer; > + struct opp_table *opp_table; > + bool has_opp_table; > /* Lock to protect xfer and IRQ accessed registers */ > spinlock_t lock; > }; > @@ -235,7 +238,7 @@ static int qcom_qspi_transfer_one(struct spi_master *master, > speed_hz = xfer->speed_hz; > > /* In regular operation (SBL_EN=1) core must be 4x transfer clock */ > - ret = clk_set_rate(ctrl->clks[QSPI_CLK_CORE].clk, speed_hz * 4); > + ret = dev_pm_opp_set_rate(ctrl->dev, speed_hz * 4); > if (ret) { > dev_err(ctrl->dev, "Failed to set core clk %d\n", ret); > return ret; > @@ -481,6 +484,20 @@ static int qcom_qspi_probe(struct platform_device *pdev) > master->handle_err = qcom_qspi_handle_err; > master->auto_runtime_pm = true; > > + ctrl->opp_table = dev_pm_opp_set_clkname(&pdev->dev, "core"); > + if (IS_ERR(ctrl->opp_table)) { > + ret = PTR_ERR(ctrl->opp_table); > + goto exit_probe_master_put; > + } > + /* OPP table is optional */ > + ret = dev_pm_opp_of_add_table(&pdev->dev); > + if (!ret) { > + ctrl->has_opp_table = true; > + } else if (ret != -ENODEV) { > + dev_err(&pdev->dev, "invalid OPP table in device tree\n"); > + goto exit_probe_master_put; > + } > + > pm_runtime_enable(dev); > > ret = spi_register_master(master); > @@ -488,6 +505,9 @@ static int qcom_qspi_probe(struct platform_device *pdev) > return 0; > > pm_runtime_disable(dev); > + if (ctrl->has_opp_table) > + dev_pm_opp_of_remove_table(&pdev->dev); > + dev_pm_opp_put_clkname(ctrl->opp_table); > > exit_probe_master_put: > spi_master_put(master); > @@ -498,6 +518,11 @@ static int qcom_qspi_probe(struct platform_device *pdev) > static int qcom_qspi_remove(struct platform_device *pdev) > { > struct spi_master *master = platform_get_drvdata(pdev); > + struct qcom_qspi *ctrl = spi_master_get_devdata(master); > + > + if (ctrl->has_opp_table) > + dev_pm_opp_of_remove_table(&pdev->dev); > + dev_pm_opp_put_clkname(ctrl->opp_table); IIUC there can still be active transfers before the controller is unregistered. If that is correct the above should be done after the spi_unregister_master() call below. > > /* Unregister _before_ disabling pm_runtime() so we stop transfers */ > spi_unregister_master(master); > @@ -512,6 +537,8 @@ static int __maybe_unused qcom_qspi_runtime_suspend(struct device *dev) > struct spi_master *master = dev_get_drvdata(dev); > struct qcom_qspi *ctrl = spi_master_get_devdata(master); > > + /* Drop the performance state vote */ > + dev_pm_opp_set_rate(dev, 0); > clk_bulk_disable_unprepare(QSPI_NUM_CLKS, ctrl->clks); > > return 0;