+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * CPU frequency scaling for OMAP using OPP information
- *
- * Copyright (C) 2005 Nokia Corporation
- * Written by Tony Lindgren <tony@atomide.com>
- *
- * Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
- *
- * Copyright (C) 2007-2011 Texas Instruments, Inc.
- * - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/cpufreq.h>
-#include <linux/delay.h>
-#include <linux/init.h>
-#include <linux/err.h>
-#include <linux/clk.h>
-#include <linux/io.h>
-#include <linux/pm_opp.h>
-#include <linux/cpu.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/regulator/consumer.h>
-
-/* OPP tolerance in percentage */
-#define OPP_TOLERANCE 4
-
-static struct cpufreq_frequency_table *freq_table;
-static atomic_t freq_table_users = ATOMIC_INIT(0);
-static struct device *mpu_dev;
-static struct regulator *mpu_reg;
-
-static int omap_target(struct cpufreq_policy *policy, unsigned int index)
-{
- int r, ret;
- struct dev_pm_opp *opp;
- unsigned long freq, volt = 0, volt_old = 0, tol = 0;
- unsigned int old_freq, new_freq;
-
- old_freq = policy->cur;
- new_freq = freq_table[index].frequency;
-
- freq = new_freq * 1000;
- ret = clk_round_rate(policy->clk, freq);
- if (ret < 0) {
- dev_warn(mpu_dev,
- "CPUfreq: Cannot find matching frequency for %lu\n",
- freq);
- return ret;
- }
- freq = ret;
-
- if (mpu_reg) {
- opp = dev_pm_opp_find_freq_ceil(mpu_dev, &freq);
- if (IS_ERR(opp)) {
- dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
- __func__, new_freq);
- return -EINVAL;
- }
- volt = dev_pm_opp_get_voltage(opp);
- dev_pm_opp_put(opp);
- tol = volt * OPP_TOLERANCE / 100;
- volt_old = regulator_get_voltage(mpu_reg);
- }
-
- dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
- old_freq / 1000, volt_old ? volt_old / 1000 : -1,
- new_freq / 1000, volt ? volt / 1000 : -1);
-
- /* scaling up? scale voltage before frequency */
- if (mpu_reg && (new_freq > old_freq)) {
- r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
- if (r < 0) {
- dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
- __func__);
- return r;
- }
- }
-
- ret = clk_set_rate(policy->clk, new_freq * 1000);
-
- /* scaling down? scale voltage after frequency */
- if (mpu_reg && (new_freq < old_freq)) {
- r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
- if (r < 0) {
- dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
- __func__);
- clk_set_rate(policy->clk, old_freq * 1000);
- return r;
- }
- }
-
- return ret;
-}
-
-static inline void freq_table_free(void)
-{
- if (atomic_dec_and_test(&freq_table_users))
- dev_pm_opp_free_cpufreq_table(mpu_dev, &freq_table);
-}
-
-static int omap_cpu_init(struct cpufreq_policy *policy)
-{
- int result;
-
- policy->clk = clk_get(NULL, "cpufreq_ck");
- if (IS_ERR(policy->clk))
- return PTR_ERR(policy->clk);
-
- if (!freq_table) {
- result = dev_pm_opp_init_cpufreq_table(mpu_dev, &freq_table);
- if (result) {
- dev_err(mpu_dev,
- "%s: cpu%d: failed creating freq table[%d]\n",
- __func__, policy->cpu, result);
- clk_put(policy->clk);
- return result;
- }
- }
-
- atomic_inc_return(&freq_table_users);
-
- /* FIXME: what's the actual transition time? */
- cpufreq_generic_init(policy, freq_table, 300 * 1000);
-
- return 0;
-}
-
-static void omap_cpu_exit(struct cpufreq_policy *policy)
-{
- freq_table_free();
- clk_put(policy->clk);
-}
-
-static struct cpufreq_driver omap_driver = {
- .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
- .verify = cpufreq_generic_frequency_table_verify,
- .target_index = omap_target,
- .get = cpufreq_generic_get,
- .init = omap_cpu_init,
- .exit = omap_cpu_exit,
- .register_em = cpufreq_register_em_with_opp,
- .name = "omap",
-};
-
-static int omap_cpufreq_probe(struct platform_device *pdev)
-{
- mpu_dev = get_cpu_device(0);
- if (!mpu_dev) {
- pr_warn("%s: unable to get the MPU device\n", __func__);
- return -EINVAL;
- }
-
- mpu_reg = regulator_get(mpu_dev, "vcc");
- if (IS_ERR(mpu_reg)) {
- pr_warn("%s: unable to get MPU regulator\n", __func__);
- mpu_reg = NULL;
- } else {
- /*
- * Ensure physical regulator is present.
- * (e.g. could be dummy regulator.)
- */
- if (regulator_get_voltage(mpu_reg) < 0) {
- pr_warn("%s: physical regulator not present for MPU\n",
- __func__);
- regulator_put(mpu_reg);
- mpu_reg = NULL;
- }
- }
-
- return cpufreq_register_driver(&omap_driver);
-}
-
-static void omap_cpufreq_remove(struct platform_device *pdev)
-{
- cpufreq_unregister_driver(&omap_driver);
-}
-
-static struct platform_driver omap_cpufreq_platdrv = {
- .driver = {
- .name = "omap-cpufreq",
- },
- .probe = omap_cpufreq_probe,
- .remove = omap_cpufreq_remove,
-};
-module_platform_driver(omap_cpufreq_platdrv);
-
-MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
-MODULE_LICENSE("GPL");
projects / thirdparty / linux.git / commitdiff
