Re: [PATCH v3 3/9] soc: samsung: Add Exynos Adaptive Supply Voltage driver

From: Krzysztof Kozlowski
Date: Wed Aug 14 2019 - 08:59:02 EST

Next message: Adrian Hunter: "[PATCH] scsi: ufs: Fix NULL pointer dereference in ufshcd_config_vreg_hpm()"
Previous message: Denis Efremov: "[PATCH] MAINTAINERS: PHY LIBRARY: Update files in the record"
In reply to: Sylwester Nawrocki: "[PATCH v3 3/9] soc: samsung: Add Exynos Adaptive Supply Voltage driver"
Next in thread: Sylwester Nawrocki: "[PATCH v3 5/9] ARM64: EXYNOS: enable exynos_chipid for ARCH_EXYNOS"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On Tue, 13 Aug 2019 at 17:08, Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> wrote:
>
> The Adaptive Supply Voltage (ASV) driver adjusts CPU cluster operating
> points depending on exact revision of an SoC retrieved from the CHIPID
> block or the OTP memory. This allows for some power saving as for some
> CPU clock frequencies we can lower CPU cluster supply voltage comparing
> to safe values common to the all chip revisions.
>
> This patch adds support for Exynos5422/5800 SoC, it is partially based
> on code from https://github.com/hardkernel/linux repository,
> branch odroidxu4-4.14.y, files: arch/arm/mach-exynos/exynos5422-asv.[ch].
>
> Tested on Odroid XU3, XU4, XU3 Lite.
>
> Signed-off-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> ---
> Changes since v2:
> - Use devm_kzalloc() in probe() to avoid memory leak,
> - removed leading spaces in exynos-chipid.h,
> - removed unneeded <linux/init.h> header inclusion,
> - dropped parentheses from exynos542_asv_parse_sg(),
> - updated Kconfig entry,
> - added const attribute to struct exynos_asv_susbsys::cpu_dt_compat.
>
> Changes since v1 (RFC):
> - removed code for parsing the ASV OPP tables from DT, the ASV OPP tables
> moved to the driver;
> - converted to use the regmap API;
> - converted to normal platform driver.
> ---
> drivers/soc/samsung/Kconfig | 10 +
> drivers/soc/samsung/Makefile | 3 +
> drivers/soc/samsung/exynos-asv.c | 184 ++++++++++
> drivers/soc/samsung/exynos-asv.h | 82 +++++
> drivers/soc/samsung/exynos5422-asv.c | 498 +++++++++++++++++++++++++++
> drivers/soc/samsung/exynos5422-asv.h | 25 ++
> 6 files changed, 802 insertions(+)
> create mode 100644 drivers/soc/samsung/exynos-asv.c
> create mode 100644 drivers/soc/samsung/exynos-asv.h
> create mode 100644 drivers/soc/samsung/exynos5422-asv.c
> create mode 100644 drivers/soc/samsung/exynos5422-asv.h
>
> diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
> index 2905f5262197..73ccf59676a1 100644
> --- a/drivers/soc/samsung/Kconfig
> +++ b/drivers/soc/samsung/Kconfig
> @@ -7,6 +7,16 @@ menuconfig SOC_SAMSUNG
>
> if SOC_SAMSUNG
>
> +config EXYNOS_ASV
> + bool "Exynos Adaptive Supply Voltage support" if COMPILE_TEST
> + depends on (ARCH_EXYNOS && EXYNOS_CHIPID) || COMPILE_TEST
> + select EXYNOS_ASV_ARM if ARM && ARCH_EXYNOS
> +
> +# There is no need to enable these drivers for ARMv8
> +config EXYNOS_ASV_ARM
> + bool "Exynos ASV ARMv7-specific driver extensions" if COMPILE_TEST
> + depends on EXYNOS_ASV
> +
> config EXYNOS_CHIPID
> bool "Exynos Chipid controller driver" if COMPILE_TEST
> depends on ARCH_EXYNOS || COMPILE_TEST
> diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
> index 3b6a8797416c..edd1d6ea064d 100644
> --- a/drivers/soc/samsung/Makefile
> +++ b/drivers/soc/samsung/Makefile
> @@ -1,5 +1,8 @@
> # SPDX-License-Identifier: GPL-2.0
>
> +obj-$(CONFIG_EXYNOS_ASV) += exynos-asv.o
> +obj-$(CONFIG_EXYNOS_ASV_ARM) += exynos5422-asv.o
> +
> obj-$(CONFIG_EXYNOS_CHIPID) += exynos-chipid.o
> obj-$(CONFIG_EXYNOS_PMU) += exynos-pmu.o
>
> diff --git a/drivers/soc/samsung/exynos-asv.c b/drivers/soc/samsung/exynos-asv.c
> new file mode 100644
> index 000000000000..481deb600afc
> --- /dev/null
> +++ b/drivers/soc/samsung/exynos-asv.c
> @@ -0,0 +1,184 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2019 Samsung Electronics Co., Ltd.
> + * http://www.samsung.com/
> + * Author: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> + *
> + * Samsung Exynos SoC Adaptive Supply Voltage support
> + */
> +
> +#include <linux/cpu.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_opp.h>
> +#include <linux/regmap.h>
> +#include <linux/soc/samsung/exynos-chipid.h>
> +
> +#include "exynos-asv.h"
> +#include "exynos5422-asv.h"
> +
> +#define MHZ 1000000U
> +
> +static int exynos_asv_update_cpu_opps(struct exynos_asv *asv,
> + struct device *cpu)
> +{
> + struct exynos_asv_subsys *subsys = NULL;
> + struct dev_pm_opp *opp;
> + unsigned int opp_freq;
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(asv->subsys); i++) {
> + if (of_device_is_compatible(cpu->of_node,
> + asv->subsys[i].cpu_dt_compat)) {
> + subsys = &asv->subsys[i];
> + break;
> + }
> + }
> + if (!subsys)
> + return -EINVAL;
> +
> + for (i = 0; i < subsys->table.num_rows; i++) {
> + unsigned int new_voltage;
> + unsigned int voltage;
> + int timeout = 1000;
> + int err;
> +
> + opp_freq = exynos_asv_opp_get_frequency(subsys, i);
> +
> + opp = dev_pm_opp_find_freq_exact(cpu, opp_freq * MHZ, true);
> + if (IS_ERR(opp)) {
> + dev_info(asv->dev, "cpu%d opp%d, freq: %u missing\n",
> + cpu->id, i, opp_freq);
> +
> + continue;
> + }
> +
> + voltage = dev_pm_opp_get_voltage(opp);
> + new_voltage = asv->opp_get_voltage(subsys, i, voltage);
> + dev_pm_opp_put(opp);
> +
> + opp_freq *= MHZ;
> + dev_pm_opp_remove(cpu, opp_freq);
> +
> + while (--timeout) {
> + opp = dev_pm_opp_find_freq_exact(cpu, opp_freq, true);
> + if (IS_ERR(opp))
> + break;
> + dev_pm_opp_put(opp);
> + msleep(1);
> + }
> +
> + err = dev_pm_opp_add(cpu, opp_freq, new_voltage);
> + if (err < 0)
> + dev_err(asv->dev,
> + "Failed to add OPP %u Hz/%u uV for cpu%d\n",
> + opp_freq, new_voltage, cpu->id);
> + }
> +
> + return 0;
> +}
> +
> +static int exynos_asv_update_opps(struct exynos_asv *asv)
> +{
> + struct opp_table *last_opp_table = NULL;
> + struct device *cpu;
> + int ret, cpuid;
> +
> + for_each_possible_cpu(cpuid) {
> + struct opp_table *opp_table;
> +
> + cpu = get_cpu_device(cpuid);
> + if (!cpu)
> + continue;
> +
> + opp_table = dev_pm_opp_get_opp_table(cpu);
> + if (IS_ERR(opp_table))
> + continue;
> +
> + if (!last_opp_table || opp_table != last_opp_table) {
> + last_opp_table = opp_table;
> +
> + ret = exynos_asv_update_cpu_opps(asv, cpu);
> + if (ret < 0)
> + dev_err(asv->dev, "Couldn't udate OPPs for cpu%d\n",
> + cpuid);
> + }
> +
> + dev_pm_opp_put_opp_table(opp_table);
> + }
> +
> + return 0;
> +}
> +
> +static int exynos_asv_probe(struct platform_device *pdev)
> +{
> + int (*probe_func)(struct exynos_asv *asv);
> + struct exynos_asv *asv;
> + struct device *cpu_dev;
> + u32 product_id = 0;
> + int ret, i;
> +
> + cpu_dev = get_cpu_device(0);
> + ret = dev_pm_opp_get_opp_count(cpu_dev);
> + if (ret < 0)
> + return -EPROBE_DEFER;
> +
> + asv = devm_kzalloc(&pdev->dev, sizeof(*asv), GFP_KERNEL);
> + if (!asv)
> + return -ENOMEM;
> +
> + asv->chipid_regmap = syscon_node_to_regmap(pdev->dev.of_node);
> + if (IS_ERR(asv->chipid_regmap)) {
> + dev_err(&pdev->dev, "Could not find syscon regmap\n");
> + return PTR_ERR(asv->chipid_regmap);
> + }
> +
> + regmap_read(asv->chipid_regmap, EXYNOS_CHIPID_REG_PRO_ID, &product_id);
> +
> + switch (product_id & EXYNOS_MASK) {
> + case 0xE5422000:
> + probe_func = exynos5422_asv_init;
> + break;
> + default:
> + dev_err(&pdev->dev, "Unsupported product ID: %#x", product_id);
> + return -ENODEV;
> + }
> +
> + ret = of_property_read_u32(pdev->dev.of_node, "samsung,asv-bin",
> + &asv->of_bin);
> + if (ret < 0)
> + asv->of_bin = -EINVAL;
> +
> + asv->dev = &pdev->dev;
> + dev_set_drvdata(&pdev->dev, asv);
> +
> + for (i = 0; i < ARRAY_SIZE(asv->subsys); i++)
> + asv->subsys[i].asv = asv;
> +
> + ret = probe_func(asv);
> + if (ret < 0)
> + return ret;
> +
> + return exynos_asv_update_opps(asv);
> +}
> +
> +static const struct of_device_id exynos_asv_of_device_ids[] = {
> + { .compatible = "samsung,exynos4210-chipid" },
> + {}
> +};
> +
> +static struct platform_driver exynos_asv_driver = {
> + .driver = {
> + .name = "exynos-asv",
> + .of_match_table = exynos_asv_of_device_ids,
> + },
> + .probe = exynos_asv_probe,
> +};
> +module_platform_driver(exynos_asv_driver);
> diff --git a/drivers/soc/samsung/exynos-asv.h b/drivers/soc/samsung/exynos-asv.h
> new file mode 100644
> index 000000000000..14b4fedf2ddd
> --- /dev/null
> +++ b/drivers/soc/samsung/exynos-asv.h
> @@ -0,0 +1,82 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2019 Samsung Electronics Co., Ltd.
> + * http://www.samsung.com/
> + * Author: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> + *
> + * Samsung Exynos SoC Adaptive Supply Voltage support
> + */
> +#ifndef __LINUX_SOC_EXYNOS_ASV_H
> +#define __LINUX_SOC_EXYNOS_ASV_H

Yikes, that was my mistake. The file is in drivers/soc, not include,
so this could stay as previous one. Or make more path dependend -
__DRIVERS_SOC... Now it is inconsistent with
drivers/soc/samsung/exynos5422-asv.h.

I can fixup these two files while applying but if there is going to be
a resend, then change both to __DRIVERS_SOC_..._H.

Best regards,
Krzysztof

Next message: Adrian Hunter: "[PATCH] scsi: ufs: Fix NULL pointer dereference in ufshcd_config_vreg_hpm()"
Previous message: Denis Efremov: "[PATCH] MAINTAINERS: PHY LIBRARY: Update files in the record"
In reply to: Sylwester Nawrocki: "[PATCH v3 3/9] soc: samsung: Add Exynos Adaptive Supply Voltage driver"
Next in thread: Sylwester Nawrocki: "[PATCH v3 5/9] ARM64: EXYNOS: enable exynos_chipid for ARCH_EXYNOS"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]