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SubjectRe: [PATCH v10 11/19] PM / devfreq: tegra20: Deprecate in a favor of emc-stat based driver
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On 11/23/20 9:27 AM, Dmitry Osipenko wrote:
> Remove tegra20-devfreq in order to replace it with a EMC_STAT based
> devfreq driver. Previously we were going to use MC_STAT based
> tegra20-devfreq driver because EMC_STAT wasn't working properly, but
> now that problem is resolved. This resolves complications imposed by
> the removed driver since it was depending on both EMC and MC drivers
> simultaneously.
>
> Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> MAINTAINERS | 1 -
> drivers/devfreq/Kconfig | 10 --
> drivers/devfreq/Makefile | 1 -
> drivers/devfreq/tegra20-devfreq.c | 210 ------------------------------
> 4 files changed, 222 deletions(-)
> delete mode 100644 drivers/devfreq/tegra20-devfreq.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5f10105cac6f..56c560320f00 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11370,7 +11370,6 @@ L: linux-pm@vger.kernel.org
> L: linux-tegra@vger.kernel.org
> T: git git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git
> S: Maintained
> -F: drivers/devfreq/tegra20-devfreq.c
> F: drivers/devfreq/tegra30-devfreq.c
>
> MEMORY MANAGEMENT
> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
> index 0ee36ae2fa79..00704efe6398 100644
> --- a/drivers/devfreq/Kconfig
> +++ b/drivers/devfreq/Kconfig
> @@ -121,16 +121,6 @@ config ARM_TEGRA_DEVFREQ
> It reads ACTMON counters of memory controllers and adjusts the
> operating frequencies and voltages with OPP support.
>
> -config ARM_TEGRA20_DEVFREQ
> - tristate "NVIDIA Tegra20 DEVFREQ Driver"
> - depends on ARCH_TEGRA_2x_SOC || COMPILE_TEST
> - depends on COMMON_CLK
> - select DEVFREQ_GOV_SIMPLE_ONDEMAND
> - help
> - This adds the DEVFREQ driver for the Tegra20 family of SoCs.
> - It reads Memory Controller counters and adjusts the operating
> - frequencies and voltages with OPP support.
> -
> config ARM_RK3399_DMC_DEVFREQ
> tristate "ARM RK3399 DMC DEVFREQ Driver"
> depends on (ARCH_ROCKCHIP && HAVE_ARM_SMCCC) || \
> diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
> index 3ca1ad0ecb97..a16333ea7034 100644
> --- a/drivers/devfreq/Makefile
> +++ b/drivers/devfreq/Makefile
> @@ -13,7 +13,6 @@ obj-$(CONFIG_ARM_IMX_BUS_DEVFREQ) += imx-bus.o
> obj-$(CONFIG_ARM_IMX8M_DDRC_DEVFREQ) += imx8m-ddrc.o
> obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o
> obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra30-devfreq.o
> -obj-$(CONFIG_ARM_TEGRA20_DEVFREQ) += tegra20-devfreq.o
>
> # DEVFREQ Event Drivers
> obj-$(CONFIG_PM_DEVFREQ_EVENT) += event/
> diff --git a/drivers/devfreq/tegra20-devfreq.c b/drivers/devfreq/tegra20-devfreq.c
> deleted file mode 100644
> index fd801534771d..000000000000
> --- a/drivers/devfreq/tegra20-devfreq.c
> +++ /dev/null
> @@ -1,210 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -/*
> - * NVIDIA Tegra20 devfreq driver
> - *
> - * Copyright (C) 2019 GRATE-DRIVER project
> - */
> -
> -#include <linux/clk.h>
> -#include <linux/devfreq.h>
> -#include <linux/io.h>
> -#include <linux/kernel.h>
> -#include <linux/module.h>
> -#include <linux/of_device.h>
> -#include <linux/platform_device.h>
> -#include <linux/pm_opp.h>
> -#include <linux/slab.h>
> -
> -#include <soc/tegra/mc.h>
> -
> -#include "governor.h"
> -
> -#define MC_STAT_CONTROL 0x90
> -#define MC_STAT_EMC_CLOCK_LIMIT 0xa0
> -#define MC_STAT_EMC_CLOCKS 0xa4
> -#define MC_STAT_EMC_CONTROL 0xa8
> -#define MC_STAT_EMC_COUNT 0xb8
> -
> -#define EMC_GATHER_CLEAR (1 << 8)
> -#define EMC_GATHER_ENABLE (3 << 8)
> -
> -struct tegra_devfreq {
> - struct devfreq *devfreq;
> - struct clk *emc_clock;
> - void __iomem *regs;
> -};
> -
> -static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
> - u32 flags)
> -{
> - struct tegra_devfreq *tegra = dev_get_drvdata(dev);
> - struct devfreq *devfreq = tegra->devfreq;
> - struct dev_pm_opp *opp;
> - unsigned long rate;
> - int err;
> -
> - opp = devfreq_recommended_opp(dev, freq, flags);
> - if (IS_ERR(opp))
> - return PTR_ERR(opp);
> -
> - rate = dev_pm_opp_get_freq(opp);
> - dev_pm_opp_put(opp);
> -
> - err = clk_set_min_rate(tegra->emc_clock, rate);
> - if (err)
> - return err;
> -
> - err = clk_set_rate(tegra->emc_clock, 0);
> - if (err)
> - goto restore_min_rate;
> -
> - return 0;
> -
> -restore_min_rate:
> - clk_set_min_rate(tegra->emc_clock, devfreq->previous_freq);
> -
> - return err;
> -}
> -
> -static int tegra_devfreq_get_dev_status(struct device *dev,
> - struct devfreq_dev_status *stat)
> -{
> - struct tegra_devfreq *tegra = dev_get_drvdata(dev);
> -
> - /*
> - * EMC_COUNT returns number of memory events, that number is lower
> - * than the number of clocks. Conversion ratio of 1/8 results in a
> - * bit higher bandwidth than actually needed, it is good enough for
> - * the time being because drivers don't support requesting minimum
> - * needed memory bandwidth yet.
> - *
> - * TODO: adjust the ratio value once relevant drivers will support
> - * memory bandwidth management.
> - */
> - stat->busy_time = readl_relaxed(tegra->regs + MC_STAT_EMC_COUNT);
> - stat->total_time = readl_relaxed(tegra->regs + MC_STAT_EMC_CLOCKS) / 8;
> - stat->current_frequency = clk_get_rate(tegra->emc_clock);
> -
> - writel_relaxed(EMC_GATHER_CLEAR, tegra->regs + MC_STAT_CONTROL);
> - writel_relaxed(EMC_GATHER_ENABLE, tegra->regs + MC_STAT_CONTROL);
> -
> - return 0;
> -}
> -
> -static struct devfreq_dev_profile tegra_devfreq_profile = {
> - .polling_ms = 500,
> - .target = tegra_devfreq_target,
> - .get_dev_status = tegra_devfreq_get_dev_status,
> -};
> -
> -static struct tegra_mc *tegra_get_memory_controller(void)
> -{
> - struct platform_device *pdev;
> - struct device_node *np;
> - struct tegra_mc *mc;
> -
> - np = of_find_compatible_node(NULL, NULL, "nvidia,tegra20-mc-gart");
> - if (!np)
> - return ERR_PTR(-ENOENT);
> -
> - pdev = of_find_device_by_node(np);
> - of_node_put(np);
> - if (!pdev)
> - return ERR_PTR(-ENODEV);
> -
> - mc = platform_get_drvdata(pdev);
> - if (!mc)
> - return ERR_PTR(-EPROBE_DEFER);
> -
> - return mc;
> -}
> -
> -static int tegra_devfreq_probe(struct platform_device *pdev)
> -{
> - struct tegra_devfreq *tegra;
> - struct tegra_mc *mc;
> - unsigned long max_rate;
> - unsigned long rate;
> - int err;
> -
> - mc = tegra_get_memory_controller();
> - if (IS_ERR(mc)) {
> - err = PTR_ERR(mc);
> - dev_err(&pdev->dev, "failed to get memory controller: %d\n",
> - err);
> - return err;
> - }
> -
> - tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
> - if (!tegra)
> - return -ENOMEM;
> -
> - /* EMC is a system-critical clock that is always enabled */
> - tegra->emc_clock = devm_clk_get(&pdev->dev, "emc");
> - if (IS_ERR(tegra->emc_clock))
> - return dev_err_probe(&pdev->dev, PTR_ERR(tegra->emc_clock),
> - "failed to get emc clock\n");
> -
> - tegra->regs = mc->regs;
> -
> - max_rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
> -
> - for (rate = 0; rate <= max_rate; rate++) {
> - rate = clk_round_rate(tegra->emc_clock, rate);
> -
> - err = dev_pm_opp_add(&pdev->dev, rate, 0);
> - if (err) {
> - dev_err(&pdev->dev, "failed to add opp: %d\n", err);
> - goto remove_opps;
> - }
> - }
> -
> - /*
> - * Reset statistic gathers state, select global bandwidth for the
> - * statistics collection mode and set clocks counter saturation
> - * limit to maximum.
> - */
> - writel_relaxed(0x00000000, tegra->regs + MC_STAT_CONTROL);
> - writel_relaxed(0x00000000, tegra->regs + MC_STAT_EMC_CONTROL);
> - writel_relaxed(0xffffffff, tegra->regs + MC_STAT_EMC_CLOCK_LIMIT);
> -
> - platform_set_drvdata(pdev, tegra);
> -
> - tegra->devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,
> - DEVFREQ_GOV_SIMPLE_ONDEMAND, NULL);
> - if (IS_ERR(tegra->devfreq)) {
> - err = PTR_ERR(tegra->devfreq);
> - goto remove_opps;
> - }
> -
> - return 0;
> -
> -remove_opps:
> - dev_pm_opp_remove_all_dynamic(&pdev->dev);
> -
> - return err;
> -}
> -
> -static int tegra_devfreq_remove(struct platform_device *pdev)
> -{
> - struct tegra_devfreq *tegra = platform_get_drvdata(pdev);
> -
> - devfreq_remove_device(tegra->devfreq);
> - dev_pm_opp_remove_all_dynamic(&pdev->dev);
> -
> - return 0;
> -}
> -
> -static struct platform_driver tegra_devfreq_driver = {
> - .probe = tegra_devfreq_probe,
> - .remove = tegra_devfreq_remove,
> - .driver = {
> - .name = "tegra20-devfreq",
> - },
> -};
> -module_platform_driver(tegra_devfreq_driver);
> -
> -MODULE_ALIAS("platform:tegra20-devfreq");
> -MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
> -MODULE_DESCRIPTION("NVIDIA Tegra20 devfreq driver");
> -MODULE_LICENSE("GPL v2");
>

Applied it. Thanks.

--
Best Regards,
Chanwoo Choi
Samsung Electronics

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