Re: [PATCH v3 15/17] spi: spi-qcom-qspi: Use OPP API to set clk/perf state

From: Rajendra Nayak
Date: Wed Apr 29 2020 - 10:21:17 EST



On 4/29/2020 6:19 AM, Matthias Kaehlcke wrote:
Hi,

On Tue, Apr 28, 2020 at 07:03:03PM +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@xxxxxxxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Alok Chauhan <alokc@xxxxxxxxxxxxxx>
Cc: Akash Asthana <akashast@xxxxxxxxxxxxxx>
Cc: linux-spi@xxxxxxxxxxxxxxx
---
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..724a658 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");
+ return ret;

goto exit_probe_master_put;

thanks for catching this. will fix and respin.


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