[PATCH v7 12/14] cpufreq: Add Kryo CPU scaling driver
Amit Kucheria
amit.kucheria at linaro.org
Wed May 16 06:12:41 PDT 2018
On Tue, May 15, 2018 at 12:13 PM, Ilia Lin <ilialin at codeaurora.org> wrote:
> In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO processors,
> the CPU ferequencies subset and voltage value of each OPP varies
s/ferequencies/frequency
> 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 at codeaurora.org>
> ---
> drivers/cpufreq/Kconfig.arm | 11 +++
> drivers/cpufreq/Makefile | 1 +
> drivers/cpufreq/cpufreq-dt-platdev.c | 3 +
> drivers/cpufreq/qcom-cpufreq-kryo.c | 150 +++++++++++++++++++++++++++++++++++
> 4 files changed, 165 insertions(+)
> create mode 100644 drivers/cpufreq/qcom-cpufreq-kryo.c
>
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index de55c7d..5c16f05 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
> + bool "Qualcomm Technologies, Inc. Kryo based CPUFreq"
"Qualcomm Kryo CPUFreq support" should be enough. Kconfig isn't the
place for Trademark compliance :-)
> + 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..10d7236
> --- /dev/null
> +++ b/drivers/cpufreq/qcom-cpufreq-kryo.c
> @@ -0,0 +1,150 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
Stray space here.
> + * Copyright (c) 2018, The Linux Foundation. All rights reserved.
> + *
> + * 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/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 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;
> + }
Use tab instead of spaces.
> +
> + 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)
Any particular reason to prefer this over (ret < 0) that is generally
used? I've seen it used to avoid the == vs. = typos, but not for other
comparisons.
Suggest sticking to what is commonly used i.e. ret < 0.
> + goto free_opp;
> +
> + cpu_dev = get_cpu_device(GOLD_LEAD);
Error check cpu_dev here?
> + ret = PTR_ERR_OR_ZERO(opp_temp =
> + dev_pm_opp_set_supported_hw(cpu_dev,&versions,1));
> + if (0 > ret)
> + goto free_opp;
> +
> +
> + ret = PTR_ERR_OR_ZERO(platform_device_register_simple("cpufreq-dt",
> + -1, NULL, 0));
> +
> + if (0 == ret)
> + return 0;
> +
> +free_opp:
> + dev_pm_opp_put_supported_hw(opp_temp);
This is not needed because dev_pm_opp_set_supported_hw will free
memory in case of failure. This call in only needed in case of a
successful get.
> +
> +free_np:
> + of_node_put(np);
> + return ret;
Suggest something like this instead:
.
.
opp_temp = dev_pm_opp_set_supported_hw(cpu_dev,&versions,1));
if (IS_ERR(opp_temp)) {
dev_err(cpu_dev, "Failed to set supported hardware\n");
ret = PTR_ERR(opp_temp);
goto free_np;
}
cpu_dev = get_cpu_device(GOLD_LEAD);
opp_temp = dev_pm_opp_set_supported_hw(cpu_dev,&versions,1));
if (IS_ERR(opp_temp)) {
dev_err(cpu_dev, "Failed to set supported hardware\n");
ret = PTR_ERR(opp_temp);
goto free_np;
}
ret = platform_device_register_simple("cpufreq-dt", -1, NULL, 0));
if (!IS_ERR_OR_NULL(ret))
goto out;
free_np:
of_node_put(np);
out:
return ret;
> +}
> +late_initcall(qcom_cpufreq_kryo_driver_init);
> +
> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Kryo CPUfreq driver");
> +MODULE_LICENSE("GPL v2");
> --
> 1.9.1
>
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