[PATCH 19/21] spi: spi-qcom-qspi: Use OPP API to set clk/perf state

Rajendra Nayak
2020-04-08T13:48:41Z

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: Alok Chauhan <alokc@codeaurora.org>
Cc: Akash Asthana <akashast@codeaurora.org>
Cc: linux-spi@vger.kernel.org
---
drivers/spi/spi-qcom-qspi.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
index 3c4f83b..42a9511 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>

@@ -235,7 +236,7 @@ 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 +482,9 @@ static int qcom_qspi_probe(struct platform_device *pdev)
master->handle_err = qcom_qspi_handle_err;
master->auto_runtime_pm = true;

+ dev_pm_opp_set_clkname(&pdev->dev, "core");
+ dev_pm_opp_of_add_table(&pdev->dev);
+
pm_runtime_enable(dev);

ret = spi_register_master(master);
@@ -490,6 +494,7 @@ static int qcom_qspi_probe(struct platform_device *pdev)
pm_runtime_disable(dev);

exit_probe_master_put:
+ dev_pm_opp_of_remove_table(&pdev->dev);
spi_master_put(master);

return ret;
@@ -499,6 +504,8 @@ static int qcom_qspi_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);

+ dev_pm_opp_of_remove_table(&pdev->dev);
+
/* Unregister _before_ disabling pm_runtime() so we stop transfers */
spi_unregister_master(master);

@@ -512,6 +519,7 @@ 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);

+ dev_pm_opp_set_rate(dev, 0);
clk_bulk_disable_unprepare(QSPI_NUM_CLKS, ctrl->clks);

return 0;