diff options
Diffstat (limited to 'drivers/devfreq/tegra-devfreq.c')
| -rw-r--r-- | drivers/devfreq/tegra-devfreq.c | 788 |
1 files changed, 788 insertions, 0 deletions
diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c new file mode 100644 index 000000000..479d9575e --- /dev/null +++ b/drivers/devfreq/tegra-devfreq.c @@ -0,0 +1,788 @@ +/* + * A devfreq driver for NVIDIA Tegra SoCs + * + * Copyright (c) 2014 NVIDIA CORPORATION. All rights reserved. + * Copyright (C) 2014 Google, Inc + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ + +#include <linux/clk.h> +#include <linux/cpufreq.h> +#include <linux/devfreq.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> +#include <linux/reset.h> + +#include "governor.h" + +#define ACTMON_GLB_STATUS 0x0 +#define ACTMON_GLB_PERIOD_CTRL 0x4 + +#define ACTMON_DEV_CTRL 0x0 +#define ACTMON_DEV_CTRL_K_VAL_SHIFT 10 +#define ACTMON_DEV_CTRL_ENB_PERIODIC BIT(18) +#define ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN BIT(20) +#define ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN BIT(21) +#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT 23 +#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT 26 +#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN BIT(29) +#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN BIT(30) +#define ACTMON_DEV_CTRL_ENB BIT(31) + +#define ACTMON_DEV_UPPER_WMARK 0x4 +#define ACTMON_DEV_LOWER_WMARK 0x8 +#define ACTMON_DEV_INIT_AVG 0xc +#define ACTMON_DEV_AVG_UPPER_WMARK 0x10 +#define ACTMON_DEV_AVG_LOWER_WMARK 0x14 +#define ACTMON_DEV_COUNT_WEIGHT 0x18 +#define ACTMON_DEV_AVG_COUNT 0x20 +#define ACTMON_DEV_INTR_STATUS 0x24 + +#define ACTMON_INTR_STATUS_CLEAR 0xffffffff + +#define ACTMON_DEV_INTR_CONSECUTIVE_UPPER BIT(31) +#define ACTMON_DEV_INTR_CONSECUTIVE_LOWER BIT(30) + +#define ACTMON_ABOVE_WMARK_WINDOW 1 +#define ACTMON_BELOW_WMARK_WINDOW 3 +#define ACTMON_BOOST_FREQ_STEP 16000 + +/* + * Activity counter is incremented every 256 memory transactions, and each + * transaction takes 4 EMC clocks for Tegra124; So the COUNT_WEIGHT is + * 4 * 256 = 1024. + */ +#define ACTMON_COUNT_WEIGHT 0x400 + +/* + * ACTMON_AVERAGE_WINDOW_LOG2: default value for @DEV_CTRL_K_VAL, which + * translates to 2 ^ (K_VAL + 1). ex: 2 ^ (6 + 1) = 128 + */ +#define ACTMON_AVERAGE_WINDOW_LOG2 6 +#define ACTMON_SAMPLING_PERIOD 12 /* ms */ +#define ACTMON_DEFAULT_AVG_BAND 6 /* 1/10 of % */ + +#define KHZ 1000 + +#define KHZ_MAX (ULONG_MAX / KHZ) + +/* Assume that the bus is saturated if the utilization is 25% */ +#define BUS_SATURATION_RATIO 25 + +/** + * struct tegra_devfreq_device_config - configuration specific to an ACTMON + * device + * + * Coefficients and thresholds are percentages unless otherwise noted + */ +struct tegra_devfreq_device_config { + u32 offset; + u32 irq_mask; + + /* Factors applied to boost_freq every consecutive watermark breach */ + unsigned int boost_up_coeff; + unsigned int boost_down_coeff; + + /* Define the watermark bounds when applied to the current avg */ + unsigned int boost_up_threshold; + unsigned int boost_down_threshold; + + /* + * Threshold of activity (cycles) below which the CPU frequency isn't + * to be taken into account. This is to avoid increasing the EMC + * frequency when the CPU is very busy but not accessing the bus often. + */ + u32 avg_dependency_threshold; +}; + +enum tegra_actmon_device { + MCALL = 0, + MCCPU, +}; + +static struct tegra_devfreq_device_config actmon_device_configs[] = { + { + /* MCALL: All memory accesses (including from the CPUs) */ + .offset = 0x1c0, + .irq_mask = 1 << 26, + .boost_up_coeff = 200, + .boost_down_coeff = 50, + .boost_up_threshold = 60, + .boost_down_threshold = 40, + }, + { + /* MCCPU: memory accesses from the CPUs */ + .offset = 0x200, + .irq_mask = 1 << 25, + .boost_up_coeff = 800, + .boost_down_coeff = 90, + .boost_up_threshold = 27, + .boost_down_threshold = 10, + .avg_dependency_threshold = 50000, + }, +}; + +/** + * struct tegra_devfreq_device - state specific to an ACTMON device + * + * Frequencies are in kHz. + */ +struct tegra_devfreq_device { + const struct tegra_devfreq_device_config *config; + void __iomem *regs; + spinlock_t lock; + + /* Average event count sampled in the last interrupt */ + u32 avg_count; + + /* + * Extra frequency to increase the target by due to consecutive + * watermark breaches. + */ + unsigned long boost_freq; + + /* Optimal frequency calculated from the stats for this device */ + unsigned long target_freq; +}; + +struct tegra_devfreq { + struct devfreq *devfreq; + + struct reset_control *reset; + struct clk *clock; + void __iomem *regs; + + struct clk *emc_clock; + unsigned long max_freq; + unsigned long cur_freq; + struct notifier_block rate_change_nb; + + struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)]; +}; + +struct tegra_actmon_emc_ratio { + unsigned long cpu_freq; + unsigned long emc_freq; +}; + +static struct tegra_actmon_emc_ratio actmon_emc_ratios[] = { + { 1400000, KHZ_MAX }, + { 1200000, 750000 }, + { 1100000, 600000 }, + { 1000000, 500000 }, + { 800000, 375000 }, + { 500000, 200000 }, + { 250000, 100000 }, +}; + +static u32 actmon_readl(struct tegra_devfreq *tegra, u32 offset) +{ + return readl(tegra->regs + offset); +} + +static void actmon_writel(struct tegra_devfreq *tegra, u32 val, u32 offset) +{ + writel(val, tegra->regs + offset); +} + +static u32 device_readl(struct tegra_devfreq_device *dev, u32 offset) +{ + return readl(dev->regs + offset); +} + +static void device_writel(struct tegra_devfreq_device *dev, u32 val, + u32 offset) +{ + writel(val, dev->regs + offset); +} + +static unsigned long do_percent(unsigned long val, unsigned int pct) +{ + return val * pct / 100; +} + +static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, + struct tegra_devfreq_device *dev) +{ + u32 avg = dev->avg_count; + u32 avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ; + u32 band = avg_band_freq * ACTMON_SAMPLING_PERIOD; + + device_writel(dev, avg + band, ACTMON_DEV_AVG_UPPER_WMARK); + + avg = max(dev->avg_count, band); + device_writel(dev, avg - band, ACTMON_DEV_AVG_LOWER_WMARK); +} + +static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra, + struct tegra_devfreq_device *dev) +{ + u32 val = tegra->cur_freq * ACTMON_SAMPLING_PERIOD; + + device_writel(dev, do_percent(val, dev->config->boost_up_threshold), + ACTMON_DEV_UPPER_WMARK); + + device_writel(dev, do_percent(val, dev->config->boost_down_threshold), + ACTMON_DEV_LOWER_WMARK); +} + +static void actmon_write_barrier(struct tegra_devfreq *tegra) +{ + /* ensure the update has reached the ACTMON */ + wmb(); + actmon_readl(tegra, ACTMON_GLB_STATUS); +} + +static void actmon_isr_device(struct tegra_devfreq *tegra, + struct tegra_devfreq_device *dev) +{ + unsigned long flags; + u32 intr_status, dev_ctrl; + + spin_lock_irqsave(&dev->lock, flags); + + dev->avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); + tegra_devfreq_update_avg_wmark(tegra, dev); + + intr_status = device_readl(dev, ACTMON_DEV_INTR_STATUS); + dev_ctrl = device_readl(dev, ACTMON_DEV_CTRL); + + if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_UPPER) { + /* + * new_boost = min(old_boost * up_coef + step, max_freq) + */ + dev->boost_freq = do_percent(dev->boost_freq, + dev->config->boost_up_coeff); + dev->boost_freq += ACTMON_BOOST_FREQ_STEP; + + dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; + + if (dev->boost_freq >= tegra->max_freq) + dev->boost_freq = tegra->max_freq; + else + dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; + } else if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_LOWER) { + /* + * new_boost = old_boost * down_coef + * or 0 if (old_boost * down_coef < step / 2) + */ + dev->boost_freq = do_percent(dev->boost_freq, + dev->config->boost_down_coeff); + + dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; + + if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1)) + dev->boost_freq = 0; + else + dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; + } + + if (dev->config->avg_dependency_threshold) { + if (dev->avg_count >= dev->config->avg_dependency_threshold) + dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; + else if (dev->boost_freq == 0) + dev_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; + } + + device_writel(dev, dev_ctrl, ACTMON_DEV_CTRL); + + device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS); + + actmon_write_barrier(tegra); + + spin_unlock_irqrestore(&dev->lock, flags); +} + +static irqreturn_t actmon_isr(int irq, void *data) +{ + struct tegra_devfreq *tegra = data; + bool handled = false; + unsigned int i; + u32 val; + + val = actmon_readl(tegra, ACTMON_GLB_STATUS); + for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { + if (val & tegra->devices[i].config->irq_mask) { + actmon_isr_device(tegra, tegra->devices + i); + handled = true; + } + } + + return handled ? IRQ_WAKE_THREAD : IRQ_NONE; +} + +static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra, + unsigned long cpu_freq) +{ + unsigned int i; + struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios; + + for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) { + if (cpu_freq >= ratio->cpu_freq) { + if (ratio->emc_freq >= tegra->max_freq) + return tegra->max_freq; + else + return ratio->emc_freq; + } + } + + return 0; +} + +static void actmon_update_target(struct tegra_devfreq *tegra, + struct tegra_devfreq_device *dev) +{ + unsigned long cpu_freq = 0; + unsigned long static_cpu_emc_freq = 0; + unsigned int avg_sustain_coef; + unsigned long flags; + + if (dev->config->avg_dependency_threshold) { + cpu_freq = cpufreq_get(0); + static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq); + } + + spin_lock_irqsave(&dev->lock, flags); + + dev->target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD; + avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold; + dev->target_freq = do_percent(dev->target_freq, avg_sustain_coef); + dev->target_freq += dev->boost_freq; + + if (dev->avg_count >= dev->config->avg_dependency_threshold) + dev->target_freq = max(dev->target_freq, static_cpu_emc_freq); + + spin_unlock_irqrestore(&dev->lock, flags); +} + +static irqreturn_t actmon_thread_isr(int irq, void *data) +{ + struct tegra_devfreq *tegra = data; + + mutex_lock(&tegra->devfreq->lock); + update_devfreq(tegra->devfreq); + mutex_unlock(&tegra->devfreq->lock); + + return IRQ_HANDLED; +} + +static int tegra_actmon_rate_notify_cb(struct notifier_block *nb, + unsigned long action, void *ptr) +{ + struct clk_notifier_data *data = ptr; + struct tegra_devfreq *tegra; + struct tegra_devfreq_device *dev; + unsigned int i; + unsigned long flags; + + if (action != POST_RATE_CHANGE) + return NOTIFY_OK; + + tegra = container_of(nb, struct tegra_devfreq, rate_change_nb); + + tegra->cur_freq = data->new_rate / KHZ; + + for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { + dev = &tegra->devices[i]; + + spin_lock_irqsave(&dev->lock, flags); + tegra_devfreq_update_wmark(tegra, dev); + spin_unlock_irqrestore(&dev->lock, flags); + } + + actmon_write_barrier(tegra); + + return NOTIFY_OK; +} + +static void tegra_actmon_enable_interrupts(struct tegra_devfreq *tegra) +{ + struct tegra_devfreq_device *dev; + u32 val; + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { + dev = &tegra->devices[i]; + + val = device_readl(dev, ACTMON_DEV_CTRL); + val |= ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN; + val |= ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN; + val |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; + val |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; + + device_writel(dev, val, ACTMON_DEV_CTRL); + } + + actmon_write_barrier(tegra); +} + +static void tegra_actmon_disable_interrupts(struct tegra_devfreq *tegra) +{ + struct tegra_devfreq_device *dev; + u32 val; + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { + dev = &tegra->devices[i]; + + val = device_readl(dev, ACTMON_DEV_CTRL); + val &= ~ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN; + val &= ~ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN; + val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; + val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; + + device_writel(dev, val, ACTMON_DEV_CTRL); + } + + actmon_write_barrier(tegra); +} + +static void tegra_actmon_configure_device(struct tegra_devfreq *tegra, + struct tegra_devfreq_device *dev) +{ + u32 val = 0; + + dev->target_freq = tegra->cur_freq; + + dev->avg_count = tegra->cur_freq * ACTMON_SAMPLING_PERIOD; + device_writel(dev, dev->avg_count, ACTMON_DEV_INIT_AVG); + + tegra_devfreq_update_avg_wmark(tegra, dev); + tegra_devfreq_update_wmark(tegra, dev); + + device_writel(dev, ACTMON_COUNT_WEIGHT, ACTMON_DEV_COUNT_WEIGHT); + device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS); + + val |= ACTMON_DEV_CTRL_ENB_PERIODIC; + val |= (ACTMON_AVERAGE_WINDOW_LOG2 - 1) + << ACTMON_DEV_CTRL_K_VAL_SHIFT; + val |= (ACTMON_BELOW_WMARK_WINDOW - 1) + << ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT; + val |= (ACTMON_ABOVE_WMARK_WINDOW - 1) + << ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT; + val |= ACTMON_DEV_CTRL_ENB; + + device_writel(dev, val, ACTMON_DEV_CTRL); + + actmon_write_barrier(tegra); +} + +static int tegra_devfreq_target(struct device *dev, unsigned long *freq, + u32 flags) +{ + struct tegra_devfreq *tegra = dev_get_drvdata(dev); + struct dev_pm_opp *opp; + unsigned long rate; + + opp = devfreq_recommended_opp(dev, freq, flags); + if (IS_ERR(opp)) { + dev_err(dev, "Failed to find opp for %lu Hz\n", *freq); + return PTR_ERR(opp); + } + rate = dev_pm_opp_get_freq(opp); + dev_pm_opp_put(opp); + + clk_set_min_rate(tegra->emc_clock, rate); + clk_set_rate(tegra->emc_clock, 0); + + return 0; +} + +static int tegra_devfreq_get_dev_status(struct device *dev, + struct devfreq_dev_status *stat) +{ + struct tegra_devfreq *tegra = dev_get_drvdata(dev); + struct tegra_devfreq_device *actmon_dev; + + stat->current_frequency = tegra->cur_freq * KHZ; + + /* To be used by the tegra governor */ + stat->private_data = tegra; + + /* The below are to be used by the other governors */ + + actmon_dev = &tegra->devices[MCALL]; + + /* Number of cycles spent on memory access */ + stat->busy_time = device_readl(actmon_dev, ACTMON_DEV_AVG_COUNT); + + /* The bus can be considered to be saturated way before 100% */ + stat->busy_time *= 100 / BUS_SATURATION_RATIO; + + /* Number of cycles in a sampling period */ + stat->total_time = ACTMON_SAMPLING_PERIOD * tegra->cur_freq; + + stat->busy_time = min(stat->busy_time, stat->total_time); + + return 0; +} + +static struct devfreq_dev_profile tegra_devfreq_profile = { + .polling_ms = 0, + .target = tegra_devfreq_target, + .get_dev_status = tegra_devfreq_get_dev_status, +}; + +static int tegra_governor_get_target(struct devfreq *devfreq, + unsigned long *freq) +{ + struct devfreq_dev_status *stat; + struct tegra_devfreq *tegra; + struct tegra_devfreq_device *dev; + unsigned long target_freq = 0; + unsigned int i; + int err; + + err = devfreq_update_stats(devfreq); + if (err) + return err; + + stat = &devfreq->last_status; + + tegra = stat->private_data; + + for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { + dev = &tegra->devices[i]; + + actmon_update_target(tegra, dev); + + target_freq = max(target_freq, dev->target_freq); + } + + *freq = target_freq * KHZ; + + return 0; +} + +static int tegra_governor_event_handler(struct devfreq *devfreq, + unsigned int event, void *data) +{ + struct tegra_devfreq *tegra; + int ret = 0; + + tegra = dev_get_drvdata(devfreq->dev.parent); + + switch (event) { + case DEVFREQ_GOV_START: + devfreq_monitor_start(devfreq); + tegra_actmon_enable_interrupts(tegra); + break; + + case DEVFREQ_GOV_STOP: + tegra_actmon_disable_interrupts(tegra); + devfreq_monitor_stop(devfreq); + break; + + case DEVFREQ_GOV_SUSPEND: + tegra_actmon_disable_interrupts(tegra); + devfreq_monitor_suspend(devfreq); + break; + + case DEVFREQ_GOV_RESUME: + devfreq_monitor_resume(devfreq); + tegra_actmon_enable_interrupts(tegra); + break; + } + + return ret; +} + +static struct devfreq_governor tegra_devfreq_governor = { + .name = "tegra_actmon", + .get_target_freq = tegra_governor_get_target, + .event_handler = tegra_governor_event_handler, +}; + +static int tegra_devfreq_probe(struct platform_device *pdev) +{ + struct tegra_devfreq *tegra; + struct tegra_devfreq_device *dev; + struct resource *res; + unsigned int i; + unsigned long rate; + int irq; + int err; + + tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL); + if (!tegra) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + tegra->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(tegra->regs)) + return PTR_ERR(tegra->regs); + + tegra->reset = devm_reset_control_get(&pdev->dev, "actmon"); + if (IS_ERR(tegra->reset)) { + dev_err(&pdev->dev, "Failed to get reset\n"); + return PTR_ERR(tegra->reset); + } + + tegra->clock = devm_clk_get(&pdev->dev, "actmon"); + if (IS_ERR(tegra->clock)) { + dev_err(&pdev->dev, "Failed to get actmon clock\n"); + return PTR_ERR(tegra->clock); + } + + tegra->emc_clock = devm_clk_get(&pdev->dev, "emc"); + if (IS_ERR(tegra->emc_clock)) { + dev_err(&pdev->dev, "Failed to get emc clock\n"); + return PTR_ERR(tegra->emc_clock); + } + + clk_set_rate(tegra->emc_clock, ULONG_MAX); + + tegra->rate_change_nb.notifier_call = tegra_actmon_rate_notify_cb; + err = clk_notifier_register(tegra->emc_clock, &tegra->rate_change_nb); + if (err) { + dev_err(&pdev->dev, + "Failed to register rate change notifier\n"); + return err; + } + + reset_control_assert(tegra->reset); + + err = clk_prepare_enable(tegra->clock); + if (err) { + dev_err(&pdev->dev, + "Failed to prepare and enable ACTMON clock\n"); + return err; + } + + reset_control_deassert(tegra->reset); + + tegra->max_freq = clk_round_rate(tegra->emc_clock, ULONG_MAX) / KHZ; + tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ; + + actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1, + ACTMON_GLB_PERIOD_CTRL); + + for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) { + dev = tegra->devices + i; + dev->config = actmon_device_configs + i; + dev->regs = tegra->regs + dev->config->offset; + spin_lock_init(&dev->lock); + + tegra_actmon_configure_device(tegra, dev); + } + + for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) { + rate = clk_round_rate(tegra->emc_clock, rate); + dev_pm_opp_add(&pdev->dev, rate, 0); + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "Failed to get IRQ: %d\n", irq); + return irq; + } + + platform_set_drvdata(pdev, tegra); + + err = devm_request_threaded_irq(&pdev->dev, irq, actmon_isr, + actmon_thread_isr, IRQF_SHARED, + "tegra-devfreq", tegra); + if (err) { + dev_err(&pdev->dev, "Interrupt request failed\n"); + return err; + } + + tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock); + tegra->devfreq = devm_devfreq_add_device(&pdev->dev, + &tegra_devfreq_profile, + "tegra_actmon", + NULL); + + return 0; +} + +static int tegra_devfreq_remove(struct platform_device *pdev) +{ + struct tegra_devfreq *tegra = platform_get_drvdata(pdev); + int irq = platform_get_irq(pdev, 0); + u32 val; + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) { + val = device_readl(&tegra->devices[i], ACTMON_DEV_CTRL); + val &= ~ACTMON_DEV_CTRL_ENB; + device_writel(&tegra->devices[i], val, ACTMON_DEV_CTRL); + } + + actmon_write_barrier(tegra); + + devm_free_irq(&pdev->dev, irq, tegra); + + clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb); + + clk_disable_unprepare(tegra->clock); + + return 0; +} + +static const struct of_device_id tegra_devfreq_of_match[] = { + { .compatible = "nvidia,tegra124-actmon" }, + { }, +}; + +MODULE_DEVICE_TABLE(of, tegra_devfreq_of_match); + +static struct platform_driver tegra_devfreq_driver = { + .probe = tegra_devfreq_probe, + .remove = tegra_devfreq_remove, + .driver = { + .name = "tegra-devfreq", + .of_match_table = tegra_devfreq_of_match, + }, +}; + +static int __init tegra_devfreq_init(void) +{ + int ret = 0; + + ret = devfreq_add_governor(&tegra_devfreq_governor); + if (ret) { + pr_err("%s: failed to add governor: %d\n", __func__, ret); + return ret; + } + + ret = platform_driver_register(&tegra_devfreq_driver); + if (ret) + devfreq_remove_governor(&tegra_devfreq_governor); + + return ret; +} +module_init(tegra_devfreq_init) + +static void __exit tegra_devfreq_exit(void) +{ + int ret = 0; + + platform_driver_unregister(&tegra_devfreq_driver); + + ret = devfreq_remove_governor(&tegra_devfreq_governor); + if (ret) + pr_err("%s: failed to remove governor: %d\n", __func__, ret); +} +module_exit(tegra_devfreq_exit) + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Tegra devfreq driver"); +MODULE_AUTHOR("Tomeu Vizoso <tomeu.vizoso@collabora.com>"); |