[V2,6/8] spi: spi-geni-qcom: Add interconnect support
diff mbox series

Message ID 1584105134-13583-7-git-send-email-akashast@codeaurora.org
State Superseded
Headers show
Series
  • Add interconnect support to QSPI and QUP drivers
Related show

Commit Message

Akash Asthana March 13, 2020, 1:12 p.m. UTC
Get the interconnect paths for SPI based Serial Engine device
and vote according to the current bus speed of the driver.

Signed-off-by: Akash Asthana <akashast@codeaurora.org>
---
 - As per Bjorn's comment, removed se == NULL check from geni_spi_icc_get
 - As per Bjorn's comment, removed code to set se->icc_path* to NULL in failure
 - As per Bjorn's comment, introduced and using devm_of_icc_get API for getting
   path handle
 - As per Matthias comment, added error handling for icc_set_bw call

 drivers/spi/spi-geni-qcom.c | 74 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 73 insertions(+), 1 deletion(-)

Comments

Mark Brown March 13, 2020, 1:16 p.m. UTC | #1
On Fri, Mar 13, 2020 at 06:42:12PM +0530, Akash Asthana wrote:

> +	se->avg_bw_cpu = Bps_to_icc(mas->cur_speed_hz);
> +	se->peak_bw_cpu = Bps_to_icc(2 * mas->cur_speed_hz);

As I commented on the previous version to no reply there seem to be a
lot of cases where the peak bandwidth is just set to double the normal
bandwidth without obvious analysis.  Should this default be centralized?
Matthias Kaehlcke March 14, 2020, 12:41 a.m. UTC | #2
Hi Akash,

On Fri, Mar 13, 2020 at 06:42:12PM +0530, Akash Asthana wrote:
> Get the interconnect paths for SPI based Serial Engine device
> and vote according to the current bus speed of the driver.
> 
> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
> ---
>  - As per Bjorn's comment, removed se == NULL check from geni_spi_icc_get
>  - As per Bjorn's comment, removed code to set se->icc_path* to NULL in failure
>  - As per Bjorn's comment, introduced and using devm_of_icc_get API for getting
>    path handle
>  - As per Matthias comment, added error handling for icc_set_bw call
> 
>  drivers/spi/spi-geni-qcom.c | 74 ++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 73 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
> index c397242..09c4709 100644
> --- a/drivers/spi/spi-geni-qcom.c
> +++ b/drivers/spi/spi-geni-qcom.c
> @@ -118,6 +118,19 @@ static int get_spi_clk_cfg(unsigned int speed_hz,
>  	return ret;
>  }
>  
> +static int geni_spi_icc_get(struct geni_se *se)
> +{
> +	se->icc_path_geni_to_core = devm_of_icc_get(se->dev, "qup-core");
> +	if (IS_ERR(se->icc_path_geni_to_core))
> +		return PTR_ERR(se->icc_path_geni_to_core);
> +
> +	se->icc_path_cpu_to_geni = devm_of_icc_get(se->dev, "qup-config");
> +	if (IS_ERR(se->icc_path_cpu_to_geni))
> +		return PTR_ERR(se->icc_path_cpu_to_geni);
> +
> +	return 0;
> +}

As per my comments on (https://patchwork.kernel.org/patch/11436895/#23222713),
the above function could be replaced by calling a 'geni_icc_get()' (or so, to
be created) provided by the geni SE driver.

> +
>  static void handle_fifo_timeout(struct spi_master *spi,
>  				struct spi_message *msg)
>  {
> @@ -234,6 +247,20 @@ static int setup_fifo_params(struct spi_device *spi_slv,
>  		return ret;
>  	}
>  
> +	/*
> +	 * Set BW quota for CPU as driver supports FIFO mode only.
> +	 * Assume peak bw as twice of avg bw.
> +	 */
> +	se->avg_bw_cpu = Bps_to_icc(mas->cur_speed_hz);
> +	se->peak_bw_cpu = Bps_to_icc(2 * mas->cur_speed_hz);
> +	ret = icc_set_bw(se->icc_path_cpu_to_geni, se->avg_bw_cpu,
> +			se->peak_bw_cpu);
> +	if (ret) {
> +		dev_err(mas->dev, "%s: ICC BW voting failed for cpu\n",
> +			__func__);
> +		return ret;
> +	}
> +
>  	clk_sel = idx & CLK_SEL_MSK;
>  	m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
>  	spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
> @@ -578,6 +605,15 @@ static int spi_geni_probe(struct platform_device *pdev)
>  	spin_lock_init(&mas->lock);
>  	pm_runtime_enable(dev);
>  
> +	ret = geni_spi_icc_get(&mas->se);
> +	if (ret)
> +		goto spi_geni_probe_runtime_disable;
> +	/* Set the bus quota to a reasonable value for register access */
> +	mas->se.avg_bw_core = Bps_to_icc(CORE_2X_50_MHZ);
> +	mas->se.peak_bw_core = Bps_to_icc(CORE_2X_100_MHZ);
> +	mas->se.avg_bw_cpu = Bps_to_icc(1000);
> +	mas->se.peak_bw_cpu = Bps_to_icc(1000);
> +
>  	ret = spi_geni_init(mas);
>  	if (ret)
>  		goto spi_geni_probe_runtime_disable;
> @@ -616,14 +652,50 @@ 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);
> +	int ret;
> +
> +	ret = geni_se_resources_off(&mas->se);
> +	if (ret)
> +		return ret;
>  
> -	return geni_se_resources_off(&mas->se);
> +	ret = icc_set_bw(mas->se.icc_path_geni_to_core, 0, 0);
> +	if (ret) {
> +		dev_err_ratelimited(mas->dev, "%s: ICC BW remove failed for core\n",
> +			__func__);
> +		return ret;
> +	}
> +
> +	ret = icc_set_bw(mas->se.icc_path_cpu_to_geni, 0, 0);
> +	if (ret) {
> +		dev_err_ratelimited(mas->dev, "%s: ICC BW remove failed for cpu\n",
> +			__func__);
> +		return ret;
> +	}

the ICC stuff above would become:

	ret = geni_icc_vote_off(&mas->se);
	if (ret)
		return ret;

with the consolidated code in geni SE.

> +
> +	return 0;
>  }
>  
>  static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
>  {
>  	struct spi_master *spi = dev_get_drvdata(dev);
>  	struct spi_geni_master *mas = spi_master_get_devdata(spi);
> +	int ret;
> +
> +	ret = icc_set_bw(mas->se.icc_path_geni_to_core, mas->se.avg_bw_core,
> +		mas->se.peak_bw_core);
> +	if (ret) {
> +		dev_err_ratelimited(mas->dev, "%s: ICC BW voting failed for core\n",
> +			__func__);
> +		return ret;
> +	}
> +
> +	ret = icc_set_bw(mas->se.icc_path_cpu_to_geni, mas->se.avg_bw_cpu,
> +		mas->se.peak_bw_cpu);
> +	if (ret) {
> +		dev_err_ratelimited(mas->dev, "%s: ICC BW voting failed for cpu\n",
> +			__func__);
> +		return ret;
> +	}

and this:

	ret = geni_icc_vote_on(&mas->se);
	if (ret)
		return ret;

>  	return geni_se_resources_on(&mas->se);

possibly you could even do the ICC voting from geni_se_resources_on/off()
it seems the two are always done together for UART, I2C and SPI.
Akash Asthana March 17, 2020, 9:35 a.m. UTC | #3
On 3/13/2020 6:46 PM, Mark Brown wrote:
> On Fri, Mar 13, 2020 at 06:42:12PM +0530, Akash Asthana wrote:
>
>> +	se->avg_bw_cpu = Bps_to_icc(mas->cur_speed_hz);
>> +	se->peak_bw_cpu = Bps_to_icc(2 * mas->cur_speed_hz);
> As I commented on the previous version to no reply there seem to be a
> lot of cases where the peak bandwidth is just set to double the normal
> bandwidth without obvious analysis.  Should this default be centralized?

Hi Mark,

I misunderstood previous comment on V1 
patch@https://patchwork.kernel.org/patch/11386479/ as a suggestion to 
mention comment for peak BW choice if nothing mentioned explicitly (in 
this case I mentioned assume peak BW twice as average).

I understand in any case I should have ack'ed the comment atleast by 
replying "ok". I am sorry about it.


We are taking care of actual throughput requirement in avg_bw vote and 
the intention of putting peak as twice of avg is to ensure that if high 
speed peripherals(ex:USB) removes their votes, we shouldn't see any 
latency issue because of other ICC client who don't vote for their BW 
requirement or *actual* BW requirement. Factor of 2 is chosen randomly. 
Please correct/improve me if this is not okay.

If this is okay, I will centralize this design for SPI QUP, I2C and UART 
driver.

Regards,

Akash
Akash Asthana March 17, 2020, 12:11 p.m. UTC | #4
Hi Matthias,

On 3/14/2020 6:11 AM, Matthias Kaehlcke wrote:
> Hi Akash,
>
> On Fri, Mar 13, 2020 at 06:42:12PM +0530, Akash Asthana wrote:
>> Get the interconnect paths for SPI based Serial Engine device
>> and vote according to the current bus speed of the driver.
>>
>> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
>> ---
>>   - As per Bjorn's comment, removed se == NULL check from geni_spi_icc_get
>>   - As per Bjorn's comment, removed code to set se->icc_path* to NULL in failure
>>   - As per Bjorn's comment, introduced and using devm_of_icc_get API for getting
>>     path handle
>>   - As per Matthias comment, added error handling for icc_set_bw call
>>
>>   drivers/spi/spi-geni-qcom.c | 74 ++++++++++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 73 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
>> index c397242..09c4709 100644
>> --- a/drivers/spi/spi-geni-qcom.c
>> +++ b/drivers/spi/spi-geni-qcom.c
>> @@ -118,6 +118,19 @@ static int get_spi_clk_cfg(unsigned int speed_hz,
>>   	return ret;
>>   }
>>   
>> +static int geni_spi_icc_get(struct geni_se *se)
>> +{
>> +	se->icc_path_geni_to_core = devm_of_icc_get(se->dev, "qup-core");
>> +	if (IS_ERR(se->icc_path_geni_to_core))
>> +		return PTR_ERR(se->icc_path_geni_to_core);
>> +
>> +	se->icc_path_cpu_to_geni = devm_of_icc_get(se->dev, "qup-config");
>> +	if (IS_ERR(se->icc_path_cpu_to_geni))
>> +		return PTR_ERR(se->icc_path_cpu_to_geni);
>> +
>> +	return 0;
>> +}
> As per my comments on (https://patchwork.kernel.org/patch/11436895/#23222713),
> the above function could be replaced by calling a 'geni_icc_get()' (or so, to
> be created) provided by the geni SE driver.
ok
>
>> +
>>   static void handle_fifo_timeout(struct spi_master *spi,
>>   				struct spi_message *msg)
>>   {
>> @@ -234,6 +247,20 @@ static int setup_fifo_params(struct spi_device *spi_slv,
>>   		return ret;
>>   	}
>>   
>> +	/*
>> +	 * Set BW quota for CPU as driver supports FIFO mode only.
>> +	 * Assume peak bw as twice of avg bw.
>> +	 */
>> +	se->avg_bw_cpu = Bps_to_icc(mas->cur_speed_hz);
>> +	se->peak_bw_cpu = Bps_to_icc(2 * mas->cur_speed_hz);
>> +	ret = icc_set_bw(se->icc_path_cpu_to_geni, se->avg_bw_cpu,
>> +			se->peak_bw_cpu);
>> +	if (ret) {
>> +		dev_err(mas->dev, "%s: ICC BW voting failed for cpu\n",
>> +			__func__);
>> +		return ret;
>> +	}
>> +
>>   	clk_sel = idx & CLK_SEL_MSK;
>>   	m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
>>   	spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
>> @@ -578,6 +605,15 @@ static int spi_geni_probe(struct platform_device *pdev)
>>   	spin_lock_init(&mas->lock);
>>   	pm_runtime_enable(dev);
>>   
>> +	ret = geni_spi_icc_get(&mas->se);
>> +	if (ret)
>> +		goto spi_geni_probe_runtime_disable;
>> +	/* Set the bus quota to a reasonable value for register access */
>> +	mas->se.avg_bw_core = Bps_to_icc(CORE_2X_50_MHZ);
>> +	mas->se.peak_bw_core = Bps_to_icc(CORE_2X_100_MHZ);
>> +	mas->se.avg_bw_cpu = Bps_to_icc(1000);
>> +	mas->se.peak_bw_cpu = Bps_to_icc(1000);
>> +
>>   	ret = spi_geni_init(mas);
>>   	if (ret)
>>   		goto spi_geni_probe_runtime_disable;
>> @@ -616,14 +652,50 @@ 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);
>> +	int ret;
>> +
>> +	ret = geni_se_resources_off(&mas->se);
>> +	if (ret)
>> +		return ret;
>>   
>> -	return geni_se_resources_off(&mas->se);
>> +	ret = icc_set_bw(mas->se.icc_path_geni_to_core, 0, 0);
>> +	if (ret) {
>> +		dev_err_ratelimited(mas->dev, "%s: ICC BW remove failed for core\n",
>> +			__func__);
>> +		return ret;
>> +	}
>> +
>> +	ret = icc_set_bw(mas->se.icc_path_cpu_to_geni, 0, 0);
>> +	if (ret) {
>> +		dev_err_ratelimited(mas->dev, "%s: ICC BW remove failed for cpu\n",
>> +			__func__);
>> +		return ret;
>> +	}
> the ICC stuff above would become:
>
> 	ret = geni_icc_vote_off(&mas->se);
> 	if (ret)
> 		return ret;
>
> with the consolidated code in geni SE.
ok
>
>> +
>> +	return 0;
>>   }
>>   
>>   static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
>>   {
>>   	struct spi_master *spi = dev_get_drvdata(dev);
>>   	struct spi_geni_master *mas = spi_master_get_devdata(spi);
>> +	int ret;
>> +
>> +	ret = icc_set_bw(mas->se.icc_path_geni_to_core, mas->se.avg_bw_core,
>> +		mas->se.peak_bw_core);
>> +	if (ret) {
>> +		dev_err_ratelimited(mas->dev, "%s: ICC BW voting failed for core\n",
>> +			__func__);
>> +		return ret;
>> +	}
>> +
>> +	ret = icc_set_bw(mas->se.icc_path_cpu_to_geni, mas->se.avg_bw_cpu,
>> +		mas->se.peak_bw_cpu);
>> +	if (ret) {
>> +		dev_err_ratelimited(mas->dev, "%s: ICC BW voting failed for cpu\n",
>> +			__func__);
>> +		return ret;
>> +	}
> and this:
>
> 	ret = geni_icc_vote_on(&mas->se);
> 	if (ret)
> 		return ret;
ok
>>   	return geni_se_resources_on(&mas->se);
> possibly you could even do the ICC voting from geni_se_resources_on/off()
> it seems the two are always done together for UART, I2C and SPI.

I think we should expose geni_icc_vote_on/off API seperately and not 
merge to resources_on/off.

Because if we merge then it will appear that we are just doing 
geni_icc_get() from individual SE driver probe not using any of ICC apis.

It looks somewhat asymmetry.


Thanks for reviewing,

Regards,

Akash
Mark Brown March 17, 2020, 1:06 p.m. UTC | #5
On Tue, Mar 17, 2020 at 03:05:21PM +0530, Akash Asthana wrote:

> We are taking care of actual throughput requirement in avg_bw vote and the
> intention of putting peak as twice of avg is to ensure that if high speed
> peripherals(ex:USB) removes their votes, we shouldn't see any latency issue
> because of other ICC client who don't vote for their BW requirement or
> *actual* BW requirement. Factor of 2 is chosen randomly. Please
> correct/improve me if this is not okay.

> If this is okay, I will centralize this design for SPI QUP, I2C and UART
> driver.

That seems reasonable to me, it was just the fact that every driver
seemed to be doing the same thing that I was noticing - what was being
done seemed OK.
Akash Asthana March 20, 2020, 1:52 p.m. UTC | #6
Hi Mark,

On 3/17/2020 6:36 PM, Mark Brown wrote:
> On Tue, Mar 17, 2020 at 03:05:21PM +0530, Akash Asthana wrote:
>
>> We are taking care of actual throughput requirement in avg_bw vote and the
>> intention of putting peak as twice of avg is to ensure that if high speed
>> peripherals(ex:USB) removes their votes, we shouldn't see any latency issue
>> because of other ICC client who don't vote for their BW requirement or
>> *actual* BW requirement. Factor of 2 is chosen randomly. Please
>> correct/improve me if this is not okay.
>> If this is okay, I will centralize this design for SPI QUP, I2C and UART
>> driver.
> That seems reasonable to me, it was just the fact that every driver
> seemed to be doing the same thing that I was noticing - what was being
> done seemed OK.

Okay, thanks for confirming I will keep as is.

Regards,

Akash

Patch
diff mbox series

diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
index c397242..09c4709 100644
--- a/drivers/spi/spi-geni-qcom.c
+++ b/drivers/spi/spi-geni-qcom.c
@@ -118,6 +118,19 @@  static int get_spi_clk_cfg(unsigned int speed_hz,
 	return ret;
 }
 
+static int geni_spi_icc_get(struct geni_se *se)
+{
+	se->icc_path_geni_to_core = devm_of_icc_get(se->dev, "qup-core");
+	if (IS_ERR(se->icc_path_geni_to_core))
+		return PTR_ERR(se->icc_path_geni_to_core);
+
+	se->icc_path_cpu_to_geni = devm_of_icc_get(se->dev, "qup-config");
+	if (IS_ERR(se->icc_path_cpu_to_geni))
+		return PTR_ERR(se->icc_path_cpu_to_geni);
+
+	return 0;
+}
+
 static void handle_fifo_timeout(struct spi_master *spi,
 				struct spi_message *msg)
 {
@@ -234,6 +247,20 @@  static int setup_fifo_params(struct spi_device *spi_slv,
 		return ret;
 	}
 
+	/*
+	 * Set BW quota for CPU as driver supports FIFO mode only.
+	 * Assume peak bw as twice of avg bw.
+	 */
+	se->avg_bw_cpu = Bps_to_icc(mas->cur_speed_hz);
+	se->peak_bw_cpu = Bps_to_icc(2 * mas->cur_speed_hz);
+	ret = icc_set_bw(se->icc_path_cpu_to_geni, se->avg_bw_cpu,
+			se->peak_bw_cpu);
+	if (ret) {
+		dev_err(mas->dev, "%s: ICC BW voting failed for cpu\n",
+			__func__);
+		return ret;
+	}
+
 	clk_sel = idx & CLK_SEL_MSK;
 	m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
 	spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
@@ -578,6 +605,15 @@  static int spi_geni_probe(struct platform_device *pdev)
 	spin_lock_init(&mas->lock);
 	pm_runtime_enable(dev);
 
+	ret = geni_spi_icc_get(&mas->se);
+	if (ret)
+		goto spi_geni_probe_runtime_disable;
+	/* Set the bus quota to a reasonable value for register access */
+	mas->se.avg_bw_core = Bps_to_icc(CORE_2X_50_MHZ);
+	mas->se.peak_bw_core = Bps_to_icc(CORE_2X_100_MHZ);
+	mas->se.avg_bw_cpu = Bps_to_icc(1000);
+	mas->se.peak_bw_cpu = Bps_to_icc(1000);
+
 	ret = spi_geni_init(mas);
 	if (ret)
 		goto spi_geni_probe_runtime_disable;
@@ -616,14 +652,50 @@  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);
+	int ret;
+
+	ret = geni_se_resources_off(&mas->se);
+	if (ret)
+		return ret;
 
-	return geni_se_resources_off(&mas->se);
+	ret = icc_set_bw(mas->se.icc_path_geni_to_core, 0, 0);
+	if (ret) {
+		dev_err_ratelimited(mas->dev, "%s: ICC BW remove failed for core\n",
+			__func__);
+		return ret;
+	}
+
+	ret = icc_set_bw(mas->se.icc_path_cpu_to_geni, 0, 0);
+	if (ret) {
+		dev_err_ratelimited(mas->dev, "%s: ICC BW remove failed for cpu\n",
+			__func__);
+		return ret;
+	}
+
+	return 0;
 }
 
 static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
 {
 	struct spi_master *spi = dev_get_drvdata(dev);
 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+	int ret;
+
+	ret = icc_set_bw(mas->se.icc_path_geni_to_core, mas->se.avg_bw_core,
+		mas->se.peak_bw_core);
+	if (ret) {
+		dev_err_ratelimited(mas->dev, "%s: ICC BW voting failed for core\n",
+			__func__);
+		return ret;
+	}
+
+	ret = icc_set_bw(mas->se.icc_path_cpu_to_geni, mas->se.avg_bw_cpu,
+		mas->se.peak_bw_cpu);
+	if (ret) {
+		dev_err_ratelimited(mas->dev, "%s: ICC BW voting failed for cpu\n",
+			__func__);
+		return ret;
+	}
 
 	return geni_se_resources_on(&mas->se);
 }