RE: [PATCH v5 12/14] cpufreq: Add Kryo CPU scaling driver

[<ilialin@codeaurora.org>]

> -----Original Message-----
> From: Viresh Kumar <viresh.kumar@linaro.org>
> Sent: Friday, May 4, 2018 09:08
> To: Ilia Lin <ilialin@codeaurora.org>
> Cc: mturquette@baylibre.com; sboyd@kernel.org; robh@kernel.org;
> mark.rutland@arm.com; rjw@rjwysocki.net; lgirdwood@gmail.com;
> broonie@kernel.org; andy.gross@linaro.org; david.brown@linaro.org;
> catalin.marinas@arm.com; will.deacon@arm.com; linux-clk@vger.kernel.org;
> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-
> pm@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-
> soc@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> rnayak@codeaurora.org; amit.kucheria@linaro.org;
> nicolas.dechesne@linaro.org; celster@codeaurora.org;
> tfinkel@codeaurora.org
> Subject: Re: [PATCH v5 12/14] cpufreq: Add Kryo CPU scaling driver
> 
> On 03-05-18, 14:52, Ilia Lin wrote:
> > In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO
> > processors, the CPU ferequencies 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          |  11 +++
> >  drivers/cpufreq/Makefile             |   1 +
> >  drivers/cpufreq/cpufreq-dt-platdev.c |   3 +
> >  drivers/cpufreq/qcom-cpufreq-kryo.c  | 153
> > +++++++++++++++++++++++++++++++++++
> >  4 files changed, 168 insertions(+)
> >  create mode 100644 drivers/cpufreq/qcom-cpufreq-kryo.c
> >
> > diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> > index de55c7d..f9da18c 100644
> > --- a/drivers/cpufreq/Kconfig.arm
> > +++ b/drivers/cpufreq/Kconfig.arm
> > @@ -124,6 +124,17 @@ config ARM_OMAP2PLUS_CPUFREQ
> >  	depends on ARCH_OMAP2PLUS
> >  	default ARCH_OMAP2PLUS
> >
> > +config ARM_QCOM_CPUFREQ_KRYO
> > +	tristate "Qualcomm Technologies, Inc. Kryo based CPUFreq"
> 
> I don't see any reply to Sricharan's query on this being tristate.

Why shouldn't we leave possibility to compile the cpufreq-dt built-in, and
the qcom-cpufreq-kryo module?

> 
> > +	depends on QCOM_QFPROM
> > +	depends on QCOM_SMEM
> > +	select PM_OPP
> > +	help
> > +	  This adds the CPUFreq driver for
> > +	  Qualcomm Technologies, Inc. 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..32371cc
> > --- /dev/null
> > +++ b/drivers/cpufreq/qcom-cpufreq-kryo.c
> > @@ -0,0 +1,153 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/* Copyright (c) 2018, The Linux Foundation. All rights reserved.
> 
> Incorrect multi line comment.

This was done as per Bjorn's instruction.

> 
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + modify
> > + * it under the terms of the GNU General Public License version 2 and
> > + * only version 2 as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#include <linux/cpu.h>
> > +#include <linux/err.h>
> > +#include <linux/init.h>
> > +//#include <linux/io.h>
> 
> ??

Not good. Will fix this.bbbbbbbb

> 
> > +#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)
> > +{
> > +	size_t len;
> > +	int ret;
> > +	u32 versions;
> > +	enum _msm8996_version msm8996_version;
> > +	u8 *speedbin;
> > +	struct platform_device *pdev;
> > +	struct device *cpu_dev;
> > +	struct device_node *np;
> > +	struct nvmem_cell *speedbin_nvmem;
> > +	struct opp_table *opp_temp = NULL;
> > +
> > +	cpu_dev = get_cpu_device(SILVER_LEAD);
> > +	if (IS_ERR_OR_NULL(cpu_dev))
> > +		return PTR_ERR(cpu_dev);
> > +
> > +	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_OR_NULL(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, "Could not get nvmem cell: %d\n", ret);
> > +		goto free_np;
> > +	}
> > +
> > +	speedbin = nvmem_cell_read(speedbin_nvmem, &len);
> > +
> > +	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;
> > +	}
> > +
> > +	ret = PTR_ERR_OR_ZERO(opp_temp = \
> > +
> dev_pm_opp_set_supported_hw(cpu_dev,&versions,1));
> > +	if (0 > ret)
> > +		goto free_np;
> > +
> > +	cpu_dev = get_cpu_device(GOLD_LEAD);
> > +	ret =
> PTR_ERR_OR_ZERO(dev_pm_opp_set_supported_hw(cpu_dev,&versions,1
> ));
> > +	if (0 > ret)
> > +		goto put_supported_hw_silver;
> > +
> > +	of_node_put(np);
> > +
> > +	pdev = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
> > +	if (IS_ERR(pdev)) {
> > +		return PTR_ERR(pdev);
> 
> Don't need to free resources on error here ?

You are right. Will fix.

> 
> > +	}
> > +
> > +	return 0;
> > +
> > +put_supported_hw_silver:
> > +	dev_pm_opp_put_supported_hw(opp_temp);
> > +
> > +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");
> > --
> > 1.9.1
> 
> --
> viresh