diff mbox

[v13,1/2] cpufreq: Add Kryo CPU scaling driver

Message ID 1527174220-13244-2-git-send-email-ilialin@codeaurora.org (mailing list archive)
State Superseded, archived
Headers show

Commit Message

Ilia Lin May 24, 2018, 3:03 p.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>
---
 drivers/cpufreq/Kconfig.arm          |  10 ++
 drivers/cpufreq/Makefile             |   1 +
 drivers/cpufreq/cpufreq-dt-platdev.c |   3 +
 drivers/cpufreq/qcom-cpufreq-kryo.c  | 206 +++++++++++++++++++++++++++++++++++
 4 files changed, 220 insertions(+)
 create mode 100644 drivers/cpufreq/qcom-cpufreq-kryo.c

Comments

Viresh Kumar May 25, 2018, 3:54 a.m. UTC | #1
On 24-05-18, 18:03, Ilia Lin wrote:
> +static int __init qcom_cpufreq_kryo_init(void)
> +{
> +	struct device_node *np;
> +	struct device *cpu_dev;
> +	int ret;
> +
> +	cpu_dev = get_cpu_device(0);
> +	if (NULL == cpu_dev)
> +		ret = -ENODEV;
> +
> +	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
> +	if (IS_ERR(np))
> +		return PTR_ERR(np);
> +
> +	ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
> +	of_node_put(np);
> +	if (!ret)
> +		return -ENOENT;
> +

I hate the fact that it is taking so long to get done with this. But can't you
just check machine compatibility instead of this complicated setup to check OPP
node ? Like:

        if (!of_device_is_compatible("qcom,apq8096") &&
            !of_device_is_compatible("qcom,msm8996"))
                return;

And please see if you can add an entry in MAINTAINERS and add your working email
id there.
Viresh Kumar May 25, 2018, 4:05 a.m. UTC | #2
On 25-05-18, 07:00, Ilia Lin wrote:
> 
> 
> On May 25, 2018 6:54:12 AM GMT+03:00, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> >On 24-05-18, 18:03, Ilia Lin wrote:
> >> +static int __init qcom_cpufreq_kryo_init(void)
> >> +{
> >> +	struct device_node *np;
> >> +	struct device *cpu_dev;
> >> +	int ret;
> >> +
> >> +	cpu_dev = get_cpu_device(0);
> >> +	if (NULL == cpu_dev)
> >> +		ret = -ENODEV;
> >> +
> >> +	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
> >> +	if (IS_ERR(np))
> >> +		return PTR_ERR(np);
> >> +
> >> +	ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
> >> +	of_node_put(np);
> >> +	if (!ret)
> >> +		return -ENOENT;
> >> +
> >
> >I hate the fact that it is taking so long to get done with this. But
> >can't you
> >just check machine compatibility instead of this complicated setup to
> >check OPP
> >node ? Like:
> >
> >        if (!of_device_is_compatible("qcom,apq8096") &&
> >            !of_device_is_compatible("qcom,msm8996"))
> >                return;
> 
> I have to check the "operating-points-v2-kryo-cpu" anyway, so I moved it from probe to the init.

Okay, leave it as is then. Don't send anything yet and wait for Sudeep to
respond.

> >
> >And please see if you can add an entry in MAINTAINERS and add your
> >working email
> >id there.
> 
> Sure. Should this be part of the patch itself?

If you need to send another version of this series, then add it to this patch
itself. Else send it separately and don't resend this stuff.
Sudeep Holla May 25, 2018, 10:48 a.m. UTC | #3
On 25/05/18 05:05, Viresh Kumar wrote:
> On 25-05-18, 07:00, Ilia Lin wrote:
>>
>>
>> On May 25, 2018 6:54:12 AM GMT+03:00, Viresh Kumar <viresh.kumar@linaro.org> wrote:
>>> On 24-05-18, 18:03, Ilia Lin wrote:
>>>> +static int __init qcom_cpufreq_kryo_init(void)
>>>> +{
>>>> +	struct device_node *np;
>>>> +	struct device *cpu_dev;
>>>> +	int ret;
>>>> +
>>>> +	cpu_dev = get_cpu_device(0);
>>>> +	if (NULL == cpu_dev)
>>>> +		ret = -ENODEV;
>>>> +
>>>> +	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
>>>> +	if (IS_ERR(np))
>>>> +		return PTR_ERR(np);
>>>> +
>>>> +	ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
>>>> +	of_node_put(np);
>>>> +	if (!ret)
>>>> +		return -ENOENT;
>>>> +
>>>
>>> I hate the fact that it is taking so long to get done with this. But
>>> can't you
>>> just check machine compatibility instead of this complicated setup to
>>> check OPP
>>> node ? Like:
>>>
>>>        if (!of_device_is_compatible("qcom,apq8096") &&
>>>            !of_device_is_compatible("qcom,msm8996"))
>>>                return;
>>
>> I have to check the "operating-points-v2-kryo-cpu" anyway, so I moved it from probe to the init.
> 
> Okay, leave it as is then. Don't send anything yet and wait for Sudeep to
> respond.
> 

I have already mentioned that I can't suggest since I don't have much
knowledge on QCOM PM. I see lots of patches flying around these days
with multiple people doing same things in different ways. That's why I
suggested Ilia to check with Taniya or Saravana or SBoyd to see what's
the best thing to do in this context. I don't prefer using OPP
compatible and would go with machine compatibility as you suggested.
But I am fine with OPP, just wanted to make sure it won't clash with
anything else.
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..bc2e885
--- /dev/null
+++ b/drivers/cpufreq/qcom-cpufreq-kryo.c
@@ -0,0 +1,206 @@ 
+// 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
+
+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);
+	if (IS_ERR(msm_id))
+		return NUM_OF_MSM8996_VERSIONS;
+
+	/* 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 qcom_cpufreq_kryo_probe(struct platform_device *pdev)
+{
+	struct opp_table *opp_tables[NR_CPUS] = {0};
+	struct platform_device *cpufreq_dt_pdev;
+	enum _msm8996_version msm8996_version;
+	struct nvmem_cell *speedbin_nvmem;
+	struct device_node *np;
+	struct device *cpu_dev;
+	unsigned cpu;
+	u8 *speedbin;
+	u32 versions;
+	size_t len;
+	int ret;
+
+	cpu_dev = get_cpu_device(0);
+	if (NULL == cpu_dev)
+		ret = -ENODEV;
+
+	msm8996_version = qcom_cpufreq_kryo_get_msm_id();
+	if (NUM_OF_MSM8996_VERSIONS == msm8996_version) {
+		dev_err(cpu_dev, "Not Snapdragon 820/821!");
+		return -ENODEV;
+	}
+
+	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
+	if (IS_ERR(np))
+		return PTR_ERR(np);
+
+	speedbin_nvmem = of_nvmem_cell_get(np, NULL);
+	of_node_put(np);
+	if (IS_ERR(speedbin_nvmem)) {
+		dev_err(cpu_dev, "Could not get nvmem cell: %ld\n",
+			PTR_ERR(speedbin_nvmem));
+		return PTR_ERR(speedbin_nvmem);
+	}
+
+	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;
+	}
+
+	for_each_possible_cpu(cpu) {
+		cpu_dev = get_cpu_device(cpu);
+		if (NULL == cpu_dev) {
+			ret = -ENODEV;
+			goto free_opp;
+		}
+
+		opp_tables[cpu] = dev_pm_opp_set_supported_hw(cpu_dev,
+							      &versions, 1);
+		if (IS_ERR(opp_tables[cpu])) {
+			ret = PTR_ERR(opp_tables[cpu]);
+			dev_err(cpu_dev, "Failed to set supported hardware\n");
+			goto free_opp;
+		}
+	}
+
+	cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
+							  NULL, 0);
+	if (!IS_ERR(cpufreq_dt_pdev))
+		return 0;
+
+	ret = PTR_ERR(cpufreq_dt_pdev);
+	dev_err(cpu_dev, "Failed to register platform device\n");
+
+free_opp:
+	for_each_possible_cpu(cpu) {
+		if (IS_ERR_OR_NULL(opp_tables[cpu]))
+			break;
+		dev_pm_opp_put_supported_hw(opp_tables[cpu]);
+	}
+
+	return ret;
+}
+
+static struct platform_driver qcom_cpufreq_kryo_driver = {
+	.probe = qcom_cpufreq_kryo_probe,
+	.driver = {
+		.name = "qcom-cpufreq-kryo",
+	},
+};
+
+/*
+ * Since the driver depends on smem and nvmem drivers, which may
+ * return EPROBE_DEFER, all the real activity is done in the probe,
+ * which may be defered as well. The init here is only registering
+ * the driver and the platform device.
+ */
+static int __init qcom_cpufreq_kryo_init(void)
+{
+	struct device_node *np;
+	struct device *cpu_dev;
+	int ret;
+
+	cpu_dev = get_cpu_device(0);
+	if (NULL == cpu_dev)
+		ret = -ENODEV;
+
+	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
+	if (IS_ERR(np))
+		return PTR_ERR(np);
+
+	ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
+	of_node_put(np);
+	if (!ret)
+		return -ENOENT;
+
+	ret = platform_driver_register(&qcom_cpufreq_kryo_driver);
+	if (unlikely(ret < 0))
+		return ret;
+
+	ret = PTR_ERR_OR_ZERO(platform_device_register_simple(
+		"qcom-cpufreq-kryo", -1, NULL, 0));
+	if (0 == ret)
+		return 0;
+
+	platform_driver_unregister(&qcom_cpufreq_kryo_driver);
+	return ret;
+}
+module_init(qcom_cpufreq_kryo_init);
+
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Kryo CPUfreq driver");
+MODULE_LICENSE("GPL v2");