diff mbox

cpufreq: Add Kryo CPU scaling driver

Message ID 1526898690-4018-1-git-send-email-ilialin@codeaurora.org (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Ilia Lin May 21, 2018, 10:31 a.m. UTC
In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO processors,
the CPU frequency subset and voltage value of each OPP varies
based on the silicon variant in use. Qualcomm Process Voltage Scaling Tables
defines the voltage and frequency value based on the msm-id in SMEM
and speedbin blown in the efuse combination.
The qcom-cpufreq-kryo driver reads the msm-id and efuse value from the SoC
to provide the OPP framework with required information.
This is used to determine the voltage and frequency value for each OPP of
operating-points-v2 table when it is parsed by the OPP framework.

Signed-off-by: Ilia Lin <ilialin@codeaurora.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/Kconfig.arm          |  10 +++
 drivers/cpufreq/Makefile             |   1 +
 drivers/cpufreq/cpufreq-dt-platdev.c |   3 +
 drivers/cpufreq/qcom-cpufreq-kryo.c  | 164 +++++++++++++++++++++++++++++++++++
 4 files changed, 178 insertions(+)
 create mode 100644 drivers/cpufreq/qcom-cpufreq-kryo.c

Comments

Viresh Kumar May 21, 2018, 10:37 a.m. UTC | #1
Would have been better if you would have updated the subject as:

[PATCH v10 10/15] cpufreq: Add Kryo CPU scaling driver

On 21-05-18, 13:31, Ilia Lin wrote:
> In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO processors,
> the CPU frequency subset and voltage value of each OPP varies
> based on the silicon variant in use. Qualcomm Process Voltage Scaling Tables
> defines the voltage and frequency value based on the msm-id in SMEM
> and speedbin blown in the efuse combination.
> The qcom-cpufreq-kryo driver reads the msm-id and efuse value from the SoC
> to provide the OPP framework with required information.
> This is used to determine the voltage and frequency value for each OPP of
> operating-points-v2 table when it is parsed by the OPP framework.
> 
> Signed-off-by: Ilia Lin <ilialin@codeaurora.org>
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

Yes, I acked it earlier, but then comments came back. You should drop
the tags in such cases normally.

Anyway, the patch looks fine now.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Russell King (Oracle) May 21, 2018, 10:54 a.m. UTC | #2
On Mon, May 21, 2018 at 01:31:30PM +0300, Ilia Lin wrote:
> +#define SILVER_LEAD	0
> +#define GOLD_LEAD	2

Okay, two different values here, but "GOLD_LEAD" appears unused.

> +	cpu_dev_silver = get_cpu_device(SILVER_LEAD);
> +	if (NULL == cpu_dev_silver)
> +		return -ENODEV;
> +
> +	cpu_dev_gold = get_cpu_device(SILVER_LEAD);
> +	if (NULL == cpu_dev_gold)
> +		return -ENODEV;

get_cpu_device() takes the logical CPU number.  So the above gets CPU 0
each time, and so cpu_dev_silver == cpu_dev_gold here.  So what's the
point of the second get_cpu_device() ?  If it's supposed to be:

	cpu_dev_gold = get_cpu_device(GOLD_LEAD);

That would get CPU 2, but in terms of these defines, it doesn't make that
much sense.  What exactly does "silver lead" and "gold lead" refer to in
these definitions?

> +	opp_silver = dev_pm_opp_set_supported_hw(cpu_dev_silver,&versions,1);
> +	if (IS_ERR(opp_silver)) {
> +		dev_err(cpu_dev_silver, "Failed to set supported hardware\n");
> +		ret = PTR_ERR(opp_silver);
> +		goto free_np;
> +	}
> +
> +	opp_gold = dev_pm_opp_set_supported_hw(cpu_dev_gold,&versions,1);
> +	if (IS_ERR(opp_gold)) {
> +		dev_err(cpu_dev_gold, "Failed to set supported hardware\n");
> +		ret = PTR_ERR(opp_gold);
> +		goto free_opp_silver;
> +	}

Given that cpu_dev_silver == cpu_dev_gold, doesn't the second call to
dev_pm_opp_set_supported_hw() always fail, as opp_table->supported_hw
will be set by the first call?

To me, this driver looks completely useless as it will always fail to
initialise, and I question whether this code has even been runtime
tested.
Ilia Lin May 21, 2018, 11:05 a.m. UTC | #3
You are right.
cpu_dev_silver != cpu_dev_gold, and I found this with my tests as well.
Thank you.

> -----Original Message-----
> From: Russell King - ARM Linux <linux@armlinux.org.uk>
> Sent: Monday, May 21, 2018 13:54
> To: Ilia Lin <ilialin@codeaurora.org>
> Cc: viresh.kumar@linaro.org; devicetree@vger.kernel.org; linux-
> pm@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-
> kernel@vger.kernel.org; linux-soc@vger.kernel.org; linux-
> clk@vger.kernel.org; linux-arm-kernel@lists.infradead.org
> Subject: Re: [PATCH] cpufreq: Add Kryo CPU scaling driver
> 
> On Mon, May 21, 2018 at 01:31:30PM +0300, Ilia Lin wrote:
> > +#define SILVER_LEAD	0
> > +#define GOLD_LEAD	2
> 
> Okay, two different values here, but "GOLD_LEAD" appears unused.
> 
> > +	cpu_dev_silver = get_cpu_device(SILVER_LEAD);
> > +	if (NULL == cpu_dev_silver)
> > +		return -ENODEV;
> > +
> > +	cpu_dev_gold = get_cpu_device(SILVER_LEAD);
> > +	if (NULL == cpu_dev_gold)
> > +		return -ENODEV;
> 
> get_cpu_device() takes the logical CPU number.  So the above gets CPU 0
> each time, and so cpu_dev_silver == cpu_dev_gold here.  So what's the
> point of the second get_cpu_device() ?  If it's supposed to be:
> 
> 	cpu_dev_gold = get_cpu_device(GOLD_LEAD);
> 
> That would get CPU 2, but in terms of these defines, it doesn't make that
> much sense.  What exactly does "silver lead" and "gold lead" refer to in
these
> definitions?
> 
> > +	opp_silver =
> dev_pm_opp_set_supported_hw(cpu_dev_silver,&versions,1);
> > +	if (IS_ERR(opp_silver)) {
> > +		dev_err(cpu_dev_silver, "Failed to set supported
> hardware\n");
> > +		ret = PTR_ERR(opp_silver);
> > +		goto free_np;
> > +	}
> > +
> > +	opp_gold =
> dev_pm_opp_set_supported_hw(cpu_dev_gold,&versions,1);
> > +	if (IS_ERR(opp_gold)) {
> > +		dev_err(cpu_dev_gold, "Failed to set supported
> hardware\n");
> > +		ret = PTR_ERR(opp_gold);
> > +		goto free_opp_silver;
> > +	}
> 
> Given that cpu_dev_silver == cpu_dev_gold, doesn't the second call to
> dev_pm_opp_set_supported_hw() always fail, as opp_table-
> >supported_hw will be set by the first call?
> 
> To me, this driver looks completely useless as it will always fail to
initialise,
> and I question whether this code has even been runtime tested.
> 
> --
> RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
> FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps
> up According to speedtest.net: 8.21Mbps down 510kbps up
Russell King (Oracle) May 21, 2018, 12:11 p.m. UTC | #4
On Mon, May 21, 2018 at 02:05:41PM +0300, ilialin@codeaurora.org wrote:
> You are right.
> cpu_dev_silver != cpu_dev_gold, and I found this with my tests as well.
> Thank you.
> 
> > -----Original Message-----
> > From: Russell King - ARM Linux <linux@armlinux.org.uk>
> > Sent: Monday, May 21, 2018 13:54
> > To: Ilia Lin <ilialin@codeaurora.org>
> > Cc: viresh.kumar@linaro.org; devicetree@vger.kernel.org; linux-
> > pm@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-
> > kernel@vger.kernel.org; linux-soc@vger.kernel.org; linux-
> > clk@vger.kernel.org; linux-arm-kernel@lists.infradead.org
> > Subject: Re: [PATCH] cpufreq: Add Kryo CPU scaling driver
> > 
> > On Mon, May 21, 2018 at 01:31:30PM +0300, Ilia Lin wrote:
> > > +#define SILVER_LEAD	0
> > > +#define GOLD_LEAD	2
> > 
> > Okay, two different values here, but "GOLD_LEAD" appears unused.
> > 
> > > +	cpu_dev_silver = get_cpu_device(SILVER_LEAD);
> > > +	if (NULL == cpu_dev_silver)
> > > +		return -ENODEV;
> > > +
> > > +	cpu_dev_gold = get_cpu_device(SILVER_LEAD);
> > > +	if (NULL == cpu_dev_gold)
> > > +		return -ENODEV;
> > 
> > get_cpu_device() takes the logical CPU number.  So the above gets CPU 0
> > each time, and so cpu_dev_silver == cpu_dev_gold here.  So what's the
> > point of the second get_cpu_device() ?  If it's supposed to be:
> > 
> > 	cpu_dev_gold = get_cpu_device(GOLD_LEAD);
> > 
> > That would get CPU 2, but in terms of these defines, it doesn't make that
> > much sense.  What exactly does "silver lead" and "gold lead" refer to in
> these
> > definitions?

I think you still need to explain this.
Ilia Lin May 21, 2018, 12:35 p.m. UTC | #5
There are 2 CPU clusters in the Kryo, CPU 0 and 1 are called Silver Cluster
and CPU 2 and 3 - Gold Cluster. Each cluster has single clock. The clusters
differ in terms of speed capabilities, computing power and power
consumption. Therefore, I define separate OPP table for each cluster, and my
driver will choose the appropriate OPP subset for each cluster.
Lead refers to first CPU in the cluster.

> -----Original Message-----
> From: Russell King - ARM Linux <linux@armlinux.org.uk>
> Sent: Monday, May 21, 2018 15:12
> To: ilialin@codeaurora.org
> Cc: viresh.kumar@linaro.org; devicetree@vger.kernel.org; linux-
> pm@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-
> kernel@vger.kernel.org; linux-soc@vger.kernel.org; linux-
> clk@vger.kernel.org; linux-arm-kernel@lists.infradead.org
> Subject: Re: [PATCH] cpufreq: Add Kryo CPU scaling driver
> 
> On Mon, May 21, 2018 at 02:05:41PM +0300, ilialin@codeaurora.org wrote:
> > You are right.
> > cpu_dev_silver != cpu_dev_gold, and I found this with my tests as well.
> > Thank you.
> >
> > > -----Original Message-----
> > > From: Russell King - ARM Linux <linux@armlinux.org.uk>
> > > Sent: Monday, May 21, 2018 13:54
> > > To: Ilia Lin <ilialin@codeaurora.org>
> > > Cc: viresh.kumar@linaro.org; devicetree@vger.kernel.org; linux-
> > > pm@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-
> > > kernel@vger.kernel.org; linux-soc@vger.kernel.org; linux-
> > > clk@vger.kernel.org; linux-arm-kernel@lists.infradead.org
> > > Subject: Re: [PATCH] cpufreq: Add Kryo CPU scaling driver
> > >
> > > On Mon, May 21, 2018 at 01:31:30PM +0300, Ilia Lin wrote:
> > > > +#define SILVER_LEAD	0
> > > > +#define GOLD_LEAD	2
> > >
> > > Okay, two different values here, but "GOLD_LEAD" appears unused.
> > >
> > > > +	cpu_dev_silver = get_cpu_device(SILVER_LEAD);
> > > > +	if (NULL == cpu_dev_silver)
> > > > +		return -ENODEV;
> > > > +
> > > > +	cpu_dev_gold = get_cpu_device(SILVER_LEAD);
> > > > +	if (NULL == cpu_dev_gold)
> > > > +		return -ENODEV;
> > >
> > > get_cpu_device() takes the logical CPU number.  So the above gets
> > > CPU 0 each time, and so cpu_dev_silver == cpu_dev_gold here.  So
> > > what's the point of the second get_cpu_device() ?  If it's supposed to
be:
> > >
> > > 	cpu_dev_gold = get_cpu_device(GOLD_LEAD);
> > >
> > > That would get CPU 2, but in terms of these defines, it doesn't make
> > > that much sense.  What exactly does "silver lead" and "gold lead"
> > > refer to in
> > these
> > > definitions?
> 
> I think you still need to explain this.
> 
> --
> RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
> FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps
> up According to speedtest.net: 8.21Mbps down 510kbps up
Russell King (Oracle) May 21, 2018, 12:41 p.m. UTC | #6
On Mon, May 21, 2018 at 03:35:07PM +0300, ilialin@codeaurora.org wrote:
> There are 2 CPU clusters in the Kryo, CPU 0 and 1 are called Silver Cluster
> and CPU 2 and 3 - Gold Cluster. Each cluster has single clock. The clusters
> differ in terms of speed capabilities, computing power and power
> consumption. Therefore, I define separate OPP table for each cluster, and my
> driver will choose the appropriate OPP subset for each cluster.
> Lead refers to first CPU in the cluster.

Ah, that is really confusing.  Lead can means many things.  Maybe a
little more verbosity with the names such as SILVER_CLUSTER_LEAD_CPU
would help?
diff mbox

Patch

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index de55c7d..0bfd40e 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -124,6 +124,16 @@  config ARM_OMAP2PLUS_CPUFREQ
 	depends on ARCH_OMAP2PLUS
 	default ARCH_OMAP2PLUS
 
+config ARM_QCOM_CPUFREQ_KRYO
+	bool "Qualcomm Kryo based CPUFreq"
+	depends on QCOM_QFPROM
+	depends on QCOM_SMEM
+	select PM_OPP
+	help
+	  This adds the CPUFreq driver for Qualcomm Kryo SoC based boards.
+
+	  If in doubt, say N.
+
 config ARM_S3C_CPUFREQ
 	bool
 	help
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 8d24ade..fb4a2ec 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -65,6 +65,7 @@  obj-$(CONFIG_MACH_MVEBU_V7)		+= mvebu-cpufreq.o
 obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ)	+= omap-cpufreq.o
 obj-$(CONFIG_ARM_PXA2xx_CPUFREQ)	+= pxa2xx-cpufreq.o
 obj-$(CONFIG_PXA3xx)			+= pxa3xx-cpufreq.o
+obj-$(CONFIG_ARM_QCOM_CPUFREQ_KRYO)	+= qcom-cpufreq-kryo.o
 obj-$(CONFIG_ARM_S3C2410_CPUFREQ)	+= s3c2410-cpufreq.o
 obj-$(CONFIG_ARM_S3C2412_CPUFREQ)	+= s3c2412-cpufreq.o
 obj-$(CONFIG_ARM_S3C2416_CPUFREQ)	+= s3c2416-cpufreq.o
diff --git a/drivers/cpufreq/cpufreq-dt-platdev.c b/drivers/cpufreq/cpufreq-dt-platdev.c
index 3b585e4..77d6ab8 100644
--- a/drivers/cpufreq/cpufreq-dt-platdev.c
+++ b/drivers/cpufreq/cpufreq-dt-platdev.c
@@ -118,6 +118,9 @@ 
 
 	{ .compatible = "nvidia,tegra124", },
 
+	{ .compatible = "qcom,apq8096", },
+	{ .compatible = "qcom,msm8996", },
+
 	{ .compatible = "st,stih407", },
 	{ .compatible = "st,stih410", },
 
diff --git a/drivers/cpufreq/qcom-cpufreq-kryo.c b/drivers/cpufreq/qcom-cpufreq-kryo.c
new file mode 100644
index 0000000..4e002d0b
--- /dev/null
+++ b/drivers/cpufreq/qcom-cpufreq-kryo.c
@@ -0,0 +1,164 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+/*
+ * In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO processors,
+ * the CPU frequency subset and voltage value of each OPP varies
+ * based on the silicon variant in use. Qualcomm Process Voltage Scaling Tables
+ * defines the voltage and frequency value based on the msm-id in SMEM
+ * and speedbin blown in the efuse combination.
+ * The qcom-cpufreq-kryo driver reads the msm-id and efuse value from the SoC
+ * to provide the OPP framework with required information.
+ * This is used to determine the voltage and frequency value for each OPP of
+ * operating-points-v2 table when it is parsed by the OPP framework.
+ */
+
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/smem.h>
+
+#define MSM_ID_SMEM	137
+#define SILVER_LEAD	0
+#define GOLD_LEAD	2
+
+enum _msm_id {
+	MSM8996V3 = 0xF6ul,
+	APQ8096V3 = 0x123ul,
+	MSM8996SG = 0x131ul,
+	APQ8096SG = 0x138ul,
+};
+
+enum _msm8996_version {
+	MSM8996_V3,
+	MSM8996_SG,
+	NUM_OF_MSM8996_VERSIONS,
+};
+
+static enum _msm8996_version __init qcom_cpufreq_kryo_get_msm_id(void)
+{
+	size_t len;
+	u32 *msm_id;
+	enum _msm8996_version version;
+
+	msm_id = qcom_smem_get(QCOM_SMEM_HOST_ANY, MSM_ID_SMEM, &len);
+	/* The first 4 bytes are format, next to them is the actual msm-id */
+	msm_id++;
+
+	switch ((enum _msm_id)*msm_id) {
+	case MSM8996V3:
+	case APQ8096V3:
+		version = MSM8996_V3;
+		break;
+	case MSM8996SG:
+	case APQ8096SG:
+		version = MSM8996_SG;
+		break;
+	default:
+		version = NUM_OF_MSM8996_VERSIONS;
+	}
+
+	return version;
+}
+
+static int __init qcom_cpufreq_kryo_driver_init(void)
+{
+	struct device *cpu_dev_silver, *cpu_dev_gold;
+	struct opp_table *opp_silver, *opp_gold;
+	enum _msm8996_version msm8996_version;
+	struct nvmem_cell *speedbin_nvmem;
+	struct platform_device *pdev;
+	struct device_node *np;
+	u8 *speedbin;
+	u32 versions;
+	size_t len;
+	int ret;
+
+	cpu_dev_silver = get_cpu_device(SILVER_LEAD);
+	if (NULL == cpu_dev_silver)
+		return -ENODEV;
+
+	cpu_dev_gold = get_cpu_device(SILVER_LEAD);
+	if (NULL == cpu_dev_gold)
+		return -ENODEV;
+
+	msm8996_version = qcom_cpufreq_kryo_get_msm_id();
+	if (NUM_OF_MSM8996_VERSIONS == msm8996_version) {
+		dev_err(cpu_dev_silver, "Not Snapdragon 820/821!");
+		return -ENODEV;
+	}
+
+	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev_silver);
+	if (IS_ERR(np))
+		return PTR_ERR(np);
+
+	if (!of_device_is_compatible(np, "operating-points-v2-kryo-cpu")) {
+		ret = -ENOENT;
+		goto free_np;
+	}
+
+	speedbin_nvmem = of_nvmem_cell_get(np, NULL);
+	if (IS_ERR(speedbin_nvmem)) {
+		ret = PTR_ERR(speedbin_nvmem);
+		dev_err(cpu_dev_silver, "Could not get nvmem cell: %d\n", ret);
+		goto free_np;
+	}
+
+	speedbin = nvmem_cell_read(speedbin_nvmem, &len);
+	nvmem_cell_put(speedbin_nvmem);
+
+	switch (msm8996_version) {
+	case MSM8996_V3:
+		versions = 1 << (unsigned int)(*speedbin);
+		break;
+	case MSM8996_SG:
+		versions = 1 << ((unsigned int)(*speedbin) + 4);
+		break;
+	default:
+		BUG();
+		break;
+	}
+
+	opp_silver = dev_pm_opp_set_supported_hw(cpu_dev_silver,&versions,1);
+	if (IS_ERR(opp_silver)) {
+		dev_err(cpu_dev_silver, "Failed to set supported hardware\n");
+		ret = PTR_ERR(opp_silver);
+		goto free_np;
+	}
+
+	opp_gold = dev_pm_opp_set_supported_hw(cpu_dev_gold,&versions,1);
+	if (IS_ERR(opp_gold)) {
+		dev_err(cpu_dev_gold, "Failed to set supported hardware\n");
+		ret = PTR_ERR(opp_gold);
+		goto free_opp_silver;
+	}
+
+	pdev = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
+	if (!IS_ERR(pdev))
+		return 0;
+
+	ret = PTR_ERR(pdev);
+	dev_err(cpu_dev_silver, "Failed to register platform device\n");
+	dev_pm_opp_put_supported_hw(opp_gold);
+
+free_opp_silver:
+	dev_pm_opp_put_supported_hw(opp_silver);
+
+free_np:
+	of_node_put(np);
+
+	return ret;
+}
+late_initcall(qcom_cpufreq_kryo_driver_init);
+
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Kryo CPUfreq driver");
+MODULE_LICENSE("GPL v2");