From 4d28ba1d62c48d5242ca30fa0051ab3498bc5c5b Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Mon, 13 May 2019 11:01:38 +0000 Subject: cpufreq: Add imx-cpufreq-dt driver Right now in upstream imx8m cpufreq support just lists a common subset of OPPs because the higher ones should only be attempted after checking speed grading in fuses. Add a small driver which checks speed grading from nvmem cells before registering cpufreq-dt. This driver allows unlocking all frequencies for imx8mm and imx8mq and could be applied to other chips like imx7d Signed-off-by: Leonard Crestez Signed-off-by: Viresh Kumar --- drivers/cpufreq/Kconfig.arm | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'drivers/cpufreq/Kconfig.arm') diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 179a1d302f48..982efdf9c7e5 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -92,6 +92,15 @@ config ARM_IMX6Q_CPUFREQ If in doubt, say N. +config ARM_IMX_CPUFREQ_DT + tristate "Freescale i.MX8M cpufreq support" + depends on ARCH_MXC && CPUFREQ_DT + help + This adds cpufreq driver support for Freescale i.MX8M series SoCs, + based on cpufreq-dt. + + If in doubt, say N. + config ARM_KIRKWOOD_CPUFREQ def_bool MACH_KIRKWOOD help -- cgit v1.2.3 From d3df18a97e586702920337056540267807b23f8e Mon Sep 17 00:00:00 2001 From: Nicolas Saenz Julienne Date: Wed, 12 Jun 2019 20:24:56 +0200 Subject: cpufreq: add driver for Raspberry Pi Raspberry Pi's firmware offers and interface though which update it's performance requirements. It allows us to request for specific runtime frequencies, which the firmware might or might not respect, depending on the firmware configuration and thermals. As the maximum and minimum frequencies are configurable in the firmware there is no way to know in advance their values. So the Raspberry Pi cpufreq driver queries them, builds an opp frequency table to then launch cpufreq-dt. Also, as the firmware interface might be configured as a module, making the cpu clock unavailable during init, this implements a full fledged driver, as opposed to most drivers registering cpufreq-dt, which only make use of an init routine. Signed-off-by: Nicolas Saenz Julienne Acked-by: Eric Anholt Reviewed-by: Stephen Boyd Acked-by: Stefan Wahren Signed-off-by: Viresh Kumar --- drivers/cpufreq/Kconfig.arm | 8 +++ drivers/cpufreq/Makefile | 1 + drivers/cpufreq/raspberrypi-cpufreq.c | 97 +++++++++++++++++++++++++++++++++++ 3 files changed, 106 insertions(+) create mode 100644 drivers/cpufreq/raspberrypi-cpufreq.c (limited to 'drivers/cpufreq/Kconfig.arm') diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 982efdf9c7e5..2499d0bccb3a 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -141,6 +141,14 @@ config ARM_QCOM_CPUFREQ_HW The driver implements the cpufreq interface for this HW engine. Say Y if you want to support CPUFreq HW. +config ARM_RASPBERRYPI_CPUFREQ + tristate "Raspberry Pi cpufreq support" + depends on CLK_RASPBERRYPI || COMPILE_TEST + help + This adds the CPUFreq driver for Raspberry Pi + + If in doubt, say N. + config ARM_S3C_CPUFREQ bool help diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index 7bcda2273d0c..5a6c70d26c98 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -65,6 +65,7 @@ obj-$(CONFIG_ARM_PXA2xx_CPUFREQ) += pxa2xx-cpufreq.o obj-$(CONFIG_PXA3xx) += pxa3xx-cpufreq.o obj-$(CONFIG_ARM_QCOM_CPUFREQ_HW) += qcom-cpufreq-hw.o obj-$(CONFIG_ARM_QCOM_CPUFREQ_KRYO) += qcom-cpufreq-kryo.o +obj-$(CONFIG_ARM_RASPBERRYPI_CPUFREQ) += raspberrypi-cpufreq.o obj-$(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/raspberrypi-cpufreq.c b/drivers/cpufreq/raspberrypi-cpufreq.c new file mode 100644 index 000000000000..2bc7d9734272 --- /dev/null +++ b/drivers/cpufreq/raspberrypi-cpufreq.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Raspberry Pi cpufreq driver + * + * Copyright (C) 2019, Nicolas Saenz Julienne + */ + +#include +#include +#include +#include +#include +#include + +#define RASPBERRYPI_FREQ_INTERVAL 100000000 + +static struct platform_device *cpufreq_dt; + +static int raspberrypi_cpufreq_probe(struct platform_device *pdev) +{ + struct device *cpu_dev; + unsigned long min, max; + unsigned long rate; + struct clk *clk; + int ret; + + cpu_dev = get_cpu_device(0); + if (!cpu_dev) { + pr_err("Cannot get CPU for cpufreq driver\n"); + return -ENODEV; + } + + clk = clk_get(cpu_dev, NULL); + if (IS_ERR(clk)) { + dev_err(cpu_dev, "Cannot get clock for CPU0\n"); + return PTR_ERR(clk); + } + + /* + * The max and min frequencies are configurable in the Raspberry Pi + * firmware, so we query them at runtime. + */ + min = roundup(clk_round_rate(clk, 0), RASPBERRYPI_FREQ_INTERVAL); + max = roundup(clk_round_rate(clk, ULONG_MAX), RASPBERRYPI_FREQ_INTERVAL); + clk_put(clk); + + for (rate = min; rate <= max; rate += RASPBERRYPI_FREQ_INTERVAL) { + ret = dev_pm_opp_add(cpu_dev, rate, 0); + if (ret) + goto remove_opp; + } + + cpufreq_dt = platform_device_register_simple("cpufreq-dt", -1, NULL, 0); + ret = PTR_ERR_OR_ZERO(cpufreq_dt); + if (ret) { + dev_err(cpu_dev, "Failed to create platform device, %d\n", ret); + goto remove_opp; + } + + return 0; + +remove_opp: + dev_pm_opp_remove_all_dynamic(cpu_dev); + + return ret; +} + +static int raspberrypi_cpufreq_remove(struct platform_device *pdev) +{ + struct device *cpu_dev; + + cpu_dev = get_cpu_device(0); + if (cpu_dev) + dev_pm_opp_remove_all_dynamic(cpu_dev); + + platform_device_unregister(cpufreq_dt); + + return 0; +} + +/* + * Since the driver depends on clk-raspberrypi, which may return EPROBE_DEFER, + * all the activity is performed in the probe, which may be defered as well. + */ +static struct platform_driver raspberrypi_cpufreq_driver = { + .driver = { + .name = "raspberrypi-cpufreq", + }, + .probe = raspberrypi_cpufreq_probe, + .remove = raspberrypi_cpufreq_remove, +}; +module_platform_driver(raspberrypi_cpufreq_driver); + +MODULE_AUTHOR("Nicolas Saenz Julienne