diff mbox series

[v5,2/6] spi: spi-geni-qcom: Use OPP API to set clk/perf state

Message ID 1589368382-19607-3-git-send-email-rnayak@codeaurora.org (mailing list archive)
State Superseded
Headers show
Series DVFS for IO devices on sdm845 and sc7180 | expand

Commit Message

Rajendra Nayak May 13, 2020, 11:12 a.m. UTC
geni spi needs to express a perforamnce state requirement on CX
depending on the frequency of 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.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.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
---
This patch will need to land via the msm tree because of a dependency
with another change.
Change in v5: OPP cleanup done as the last thing in spi_geni_remove()

 drivers/spi/spi-geni-qcom.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

Comments

Bjorn Andersson May 13, 2020, 7:07 p.m. UTC | #1
On Wed 13 May 04:12 PDT 2020, Rajendra Nayak wrote:

> geni spi needs to express a perforamnce state requirement on CX
> depending on the frequency of 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.
> 
> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
> Reviewed-by: Matthias Kaehlcke <mka@chromium.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
> ---
> This patch will need to land via the msm tree because of a dependency
> with another change.
> Change in v5: OPP cleanup done as the last thing in spi_geni_remove()
> 
>  drivers/spi/spi-geni-qcom.c | 26 +++++++++++++++++++++++---
>  1 file changed, 23 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
> index c397242..0d7ead1 100644
> --- a/drivers/spi/spi-geni-qcom.c
> +++ b/drivers/spi/spi-geni-qcom.c
> @@ -7,6 +7,7 @@
>  #include <linux/log2.h>
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_opp.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/qcom-geni-se.h>
>  #include <linux/spi/spi.h>
> @@ -95,7 +96,6 @@ static int get_spi_clk_cfg(unsigned int speed_hz,
>  {
>  	unsigned long sclk_freq;
>  	unsigned int actual_hz;
> -	struct geni_se *se = &mas->se;
>  	int ret;
>  
>  	ret = geni_se_clk_freq_match(&mas->se,
> @@ -112,9 +112,9 @@ static int get_spi_clk_cfg(unsigned int speed_hz,
>  
>  	dev_dbg(mas->dev, "req %u=>%u sclk %lu, idx %d, div %d\n", speed_hz,
>  				actual_hz, sclk_freq, *clk_idx, *clk_div);
> -	ret = clk_set_rate(se->clk, sclk_freq);
> +	ret = dev_pm_opp_set_rate(mas->dev, sclk_freq);
>  	if (ret)
> -		dev_err(mas->dev, "clk_set_rate failed %d\n", ret);
> +		dev_err(mas->dev, "dev_pm_opp_set_rate failed %d\n", ret);
>  	return ret;
>  }
>  
> @@ -561,6 +561,17 @@ static int spi_geni_probe(struct platform_device *pdev)
>  	mas->se.wrapper = dev_get_drvdata(dev->parent);
>  	mas->se.base = base;
>  	mas->se.clk = clk;
> +	mas->se.opp_table = dev_pm_opp_set_clkname(&pdev->dev, "se");
> +	if (IS_ERR(mas->se.opp_table))
> +		return PTR_ERR(mas->se.opp_table);
> +	/* OPP table is optional */
> +	ret = dev_pm_opp_of_add_table(&pdev->dev);
> +	if (!ret) {
> +		mas->se.has_opp_table = true;
> +	} else if (ret != -ENODEV) {
> +		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
> +		return ret;
> +	}
>  
>  	spi->bus_num = -1;
>  	spi->dev.of_node = dev->of_node;
> @@ -596,6 +607,9 @@ static int spi_geni_probe(struct platform_device *pdev)
>  spi_geni_probe_runtime_disable:
>  	pm_runtime_disable(dev);
>  	spi_master_put(spi);
> +	if (mas->se.has_opp_table)

Why do you need has_opp_table?

Afaict if dev_pm_opp_of_add_table() returns -ENODEV there's no attached
opp-table and dev_pm_opp_of_remove_table() is a nop.

Regards,
Bjorn

> +		dev_pm_opp_of_remove_table(&pdev->dev);
> +	dev_pm_opp_put_clkname(mas->se.opp_table);
>  	return ret;
>  }
>  
> @@ -609,6 +623,9 @@ static int spi_geni_remove(struct platform_device *pdev)
>  
>  	free_irq(mas->irq, spi);
>  	pm_runtime_disable(&pdev->dev);
> +	if (mas->se.has_opp_table)
> +		dev_pm_opp_of_remove_table(&pdev->dev);
> +	dev_pm_opp_put_clkname(mas->se.opp_table);
>  	return 0;
>  }
>  
> @@ -617,6 +634,9 @@ static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
>  	struct spi_master *spi = dev_get_drvdata(dev);
>  	struct spi_geni_master *mas = spi_master_get_devdata(spi);
>  
> +	/* Drop the performance state vote */
> +	dev_pm_opp_set_rate(dev, 0);
> +
>  	return geni_se_resources_off(&mas->se);
>  }
>  
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
Rajendra Nayak May 14, 2020, 5:03 a.m. UTC | #2
[]..

>>   
>>   	spi->bus_num = -1;
>>   	spi->dev.of_node = dev->of_node;
>> @@ -596,6 +607,9 @@ static int spi_geni_probe(struct platform_device *pdev)
>>   spi_geni_probe_runtime_disable:
>>   	pm_runtime_disable(dev);
>>   	spi_master_put(spi);
>> +	if (mas->se.has_opp_table)
> 
> Why do you need has_opp_table?
> 
> Afaict if dev_pm_opp_of_add_table() returns -ENODEV there's no attached
> opp-table and dev_pm_opp_of_remove_table() is a nop.

Apparently its not. Calling dev_pm_opp_of_remove_table() when dev_pm_opp_of_add_table()
failed causes use-count mismatch.
You can see https://lkml.org/lkml/2020/4/15/18 for more details.
Bjorn Andersson May 14, 2020, 5:38 a.m. UTC | #3
On Wed 13 May 22:03 PDT 2020, Rajendra Nayak wrote:

> 
> []..
> 
> > >   	spi->bus_num = -1;
> > >   	spi->dev.of_node = dev->of_node;
> > > @@ -596,6 +607,9 @@ static int spi_geni_probe(struct platform_device *pdev)
> > >   spi_geni_probe_runtime_disable:
> > >   	pm_runtime_disable(dev);
> > >   	spi_master_put(spi);
> > > +	if (mas->se.has_opp_table)
> > 
> > Why do you need has_opp_table?
> > 
> > Afaict if dev_pm_opp_of_add_table() returns -ENODEV there's no attached
> > opp-table and dev_pm_opp_of_remove_table() is a nop.
> 
> Apparently its not. Calling dev_pm_opp_of_remove_table() when dev_pm_opp_of_add_table()
> failed causes use-count mismatch.
> You can see https://lkml.org/lkml/2020/4/15/18 for more details.
> 

Must have missed that when I glanced at the code, thanks for clarifying.

Regards,
Bjorn

> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
Mark Brown May 26, 2020, 10:39 a.m. UTC | #4
On Wed, May 13, 2020 at 04:42:58PM +0530, Rajendra Nayak wrote:
> geni spi needs to express a perforamnce state requirement on CX
> depending on the frequency of 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.

Acked-by: Mark Brown <broonie@kernel.org>
diff mbox series

Patch

diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
index c397242..0d7ead1 100644
--- a/drivers/spi/spi-geni-qcom.c
+++ b/drivers/spi/spi-geni-qcom.c
@@ -7,6 +7,7 @@ 
 #include <linux/log2.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/pm_opp.h>
 #include <linux/pm_runtime.h>
 #include <linux/qcom-geni-se.h>
 #include <linux/spi/spi.h>
@@ -95,7 +96,6 @@  static int get_spi_clk_cfg(unsigned int speed_hz,
 {
 	unsigned long sclk_freq;
 	unsigned int actual_hz;
-	struct geni_se *se = &mas->se;
 	int ret;
 
 	ret = geni_se_clk_freq_match(&mas->se,
@@ -112,9 +112,9 @@  static int get_spi_clk_cfg(unsigned int speed_hz,
 
 	dev_dbg(mas->dev, "req %u=>%u sclk %lu, idx %d, div %d\n", speed_hz,
 				actual_hz, sclk_freq, *clk_idx, *clk_div);
-	ret = clk_set_rate(se->clk, sclk_freq);
+	ret = dev_pm_opp_set_rate(mas->dev, sclk_freq);
 	if (ret)
-		dev_err(mas->dev, "clk_set_rate failed %d\n", ret);
+		dev_err(mas->dev, "dev_pm_opp_set_rate failed %d\n", ret);
 	return ret;
 }
 
@@ -561,6 +561,17 @@  static int spi_geni_probe(struct platform_device *pdev)
 	mas->se.wrapper = dev_get_drvdata(dev->parent);
 	mas->se.base = base;
 	mas->se.clk = clk;
+	mas->se.opp_table = dev_pm_opp_set_clkname(&pdev->dev, "se");
+	if (IS_ERR(mas->se.opp_table))
+		return PTR_ERR(mas->se.opp_table);
+	/* OPP table is optional */
+	ret = dev_pm_opp_of_add_table(&pdev->dev);
+	if (!ret) {
+		mas->se.has_opp_table = true;
+	} else if (ret != -ENODEV) {
+		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
+		return ret;
+	}
 
 	spi->bus_num = -1;
 	spi->dev.of_node = dev->of_node;
@@ -596,6 +607,9 @@  static int spi_geni_probe(struct platform_device *pdev)
 spi_geni_probe_runtime_disable:
 	pm_runtime_disable(dev);
 	spi_master_put(spi);
+	if (mas->se.has_opp_table)
+		dev_pm_opp_of_remove_table(&pdev->dev);
+	dev_pm_opp_put_clkname(mas->se.opp_table);
 	return ret;
 }
 
@@ -609,6 +623,9 @@  static int spi_geni_remove(struct platform_device *pdev)
 
 	free_irq(mas->irq, spi);
 	pm_runtime_disable(&pdev->dev);
+	if (mas->se.has_opp_table)
+		dev_pm_opp_of_remove_table(&pdev->dev);
+	dev_pm_opp_put_clkname(mas->se.opp_table);
 	return 0;
 }
 
@@ -617,6 +634,9 @@  static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
 	struct spi_master *spi = dev_get_drvdata(dev);
 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
 
+	/* Drop the performance state vote */
+	dev_pm_opp_set_rate(dev, 0);
+
 	return geni_se_resources_off(&mas->se);
 }