| /* |
| * Copyright (C) 2013 Freescale Semiconductor, Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #include <linux/clk.h> |
| #include <linux/cpufreq.h> |
| #include <linux/delay.h> |
| #include <linux/err.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/opp.h> |
| #include <linux/platform_device.h> |
| #include <linux/regulator/consumer.h> |
| |
| #define PU_SOC_VOLTAGE_NORMAL 1250000 |
| #define PU_SOC_VOLTAGE_HIGH 1275000 |
| #define FREQ_1P2_GHZ 1200000000 |
| |
| static struct regulator *arm_reg; |
| static struct regulator *pu_reg; |
| static struct regulator *soc_reg; |
| |
| static struct clk *arm_clk; |
| static struct clk *pll1_sys_clk; |
| static struct clk *pll1_sw_clk; |
| static struct clk *step_clk; |
| static struct clk *pll2_pfd2_396m_clk; |
| |
| static struct device *cpu_dev; |
| static struct cpufreq_frequency_table *freq_table; |
| static unsigned int transition_latency; |
| |
| static int imx6q_verify_speed(struct cpufreq_policy *policy) |
| { |
| return cpufreq_frequency_table_verify(policy, freq_table); |
| } |
| |
| static unsigned int imx6q_get_speed(unsigned int cpu) |
| { |
| return clk_get_rate(arm_clk) / 1000; |
| } |
| |
| static int imx6q_set_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, unsigned int relation) |
| { |
| struct cpufreq_freqs freqs; |
| struct opp *opp; |
| unsigned long freq_hz, volt, volt_old; |
| unsigned int index, cpu; |
| int ret; |
| |
| ret = cpufreq_frequency_table_target(policy, freq_table, target_freq, |
| relation, &index); |
| if (ret) { |
| dev_err(cpu_dev, "failed to match target frequency %d: %d\n", |
| target_freq, ret); |
| return ret; |
| } |
| |
| freqs.new = freq_table[index].frequency; |
| freq_hz = freqs.new * 1000; |
| freqs.old = clk_get_rate(arm_clk) / 1000; |
| |
| if (freqs.old == freqs.new) |
| return 0; |
| |
| for_each_online_cpu(cpu) { |
| freqs.cpu = cpu; |
| cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); |
| } |
| |
| rcu_read_lock(); |
| opp = opp_find_freq_ceil(cpu_dev, &freq_hz); |
| if (IS_ERR(opp)) { |
| rcu_read_unlock(); |
| dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_hz); |
| return PTR_ERR(opp); |
| } |
| |
| volt = opp_get_voltage(opp); |
| rcu_read_unlock(); |
| volt_old = regulator_get_voltage(arm_reg); |
| |
| dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n", |
| freqs.old / 1000, volt_old / 1000, |
| freqs.new / 1000, volt / 1000); |
| |
| /* scaling up? scale voltage before frequency */ |
| if (freqs.new > freqs.old) { |
| ret = regulator_set_voltage_tol(arm_reg, volt, 0); |
| if (ret) { |
| dev_err(cpu_dev, |
| "failed to scale vddarm up: %d\n", ret); |
| return ret; |
| } |
| |
| /* |
| * Need to increase vddpu and vddsoc for safety |
| * if we are about to run at 1.2 GHz. |
| */ |
| if (freqs.new == FREQ_1P2_GHZ / 1000) { |
| regulator_set_voltage_tol(pu_reg, |
| PU_SOC_VOLTAGE_HIGH, 0); |
| regulator_set_voltage_tol(soc_reg, |
| PU_SOC_VOLTAGE_HIGH, 0); |
| } |
| } |
| |
| /* |
| * The setpoints are selected per PLL/PDF frequencies, so we need to |
| * reprogram PLL for frequency scaling. The procedure of reprogramming |
| * PLL1 is as below. |
| * |
| * - Enable pll2_pfd2_396m_clk and reparent pll1_sw_clk to it |
| * - Reprogram pll1_sys_clk and reparent pll1_sw_clk back to it |
| * - Disable pll2_pfd2_396m_clk |
| */ |
| clk_prepare_enable(pll2_pfd2_396m_clk); |
| clk_set_parent(step_clk, pll2_pfd2_396m_clk); |
| clk_set_parent(pll1_sw_clk, step_clk); |
| if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) { |
| clk_set_rate(pll1_sys_clk, freqs.new * 1000); |
| /* |
| * If we are leaving 396 MHz set-point, we need to enable |
| * pll1_sys_clk and disable pll2_pfd2_396m_clk to keep |
| * their use count correct. |
| */ |
| if (freqs.old * 1000 <= clk_get_rate(pll2_pfd2_396m_clk)) { |
| clk_prepare_enable(pll1_sys_clk); |
| clk_disable_unprepare(pll2_pfd2_396m_clk); |
| } |
| clk_set_parent(pll1_sw_clk, pll1_sys_clk); |
| clk_disable_unprepare(pll2_pfd2_396m_clk); |
| } else { |
| /* |
| * Disable pll1_sys_clk if pll2_pfd2_396m_clk is sufficient |
| * to provide the frequency. |
| */ |
| clk_disable_unprepare(pll1_sys_clk); |
| } |
| |
| /* Ensure the arm clock divider is what we expect */ |
| ret = clk_set_rate(arm_clk, freqs.new * 1000); |
| if (ret) { |
| dev_err(cpu_dev, "failed to set clock rate: %d\n", ret); |
| regulator_set_voltage_tol(arm_reg, volt_old, 0); |
| return ret; |
| } |
| |
| /* scaling down? scale voltage after frequency */ |
| if (freqs.new < freqs.old) { |
| ret = regulator_set_voltage_tol(arm_reg, volt, 0); |
| if (ret) |
| dev_warn(cpu_dev, |
| "failed to scale vddarm down: %d\n", ret); |
| |
| if (freqs.old == FREQ_1P2_GHZ / 1000) { |
| regulator_set_voltage_tol(pu_reg, |
| PU_SOC_VOLTAGE_NORMAL, 0); |
| regulator_set_voltage_tol(soc_reg, |
| PU_SOC_VOLTAGE_NORMAL, 0); |
| } |
| } |
| |
| for_each_online_cpu(cpu) { |
| freqs.cpu = cpu; |
| cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); |
| } |
| |
| return 0; |
| } |
| |
| static int imx6q_cpufreq_init(struct cpufreq_policy *policy) |
| { |
| int ret; |
| |
| ret = cpufreq_frequency_table_cpuinfo(policy, freq_table); |
| if (ret) { |
| dev_err(cpu_dev, "invalid frequency table: %d\n", ret); |
| return ret; |
| } |
| |
| policy->cpuinfo.transition_latency = transition_latency; |
| policy->cur = clk_get_rate(arm_clk) / 1000; |
| cpumask_setall(policy->cpus); |
| cpufreq_frequency_table_get_attr(freq_table, policy->cpu); |
| |
| return 0; |
| } |
| |
| static int imx6q_cpufreq_exit(struct cpufreq_policy *policy) |
| { |
| cpufreq_frequency_table_put_attr(policy->cpu); |
| return 0; |
| } |
| |
| static struct freq_attr *imx6q_cpufreq_attr[] = { |
| &cpufreq_freq_attr_scaling_available_freqs, |
| NULL, |
| }; |
| |
| static struct cpufreq_driver imx6q_cpufreq_driver = { |
| .verify = imx6q_verify_speed, |
| .target = imx6q_set_target, |
| .get = imx6q_get_speed, |
| .init = imx6q_cpufreq_init, |
| .exit = imx6q_cpufreq_exit, |
| .name = "imx6q-cpufreq", |
| .attr = imx6q_cpufreq_attr, |
| }; |
| |
| static int imx6q_cpufreq_probe(struct platform_device *pdev) |
| { |
| struct device_node *np; |
| struct opp *opp; |
| unsigned long min_volt, max_volt; |
| int num, ret; |
| |
| cpu_dev = &pdev->dev; |
| |
| np = of_find_node_by_path("/cpus/cpu@0"); |
| if (!np) { |
| dev_err(cpu_dev, "failed to find cpu0 node\n"); |
| return -ENOENT; |
| } |
| |
| cpu_dev->of_node = np; |
| |
| arm_clk = devm_clk_get(cpu_dev, "arm"); |
| pll1_sys_clk = devm_clk_get(cpu_dev, "pll1_sys"); |
| pll1_sw_clk = devm_clk_get(cpu_dev, "pll1_sw"); |
| step_clk = devm_clk_get(cpu_dev, "step"); |
| pll2_pfd2_396m_clk = devm_clk_get(cpu_dev, "pll2_pfd2_396m"); |
| if (IS_ERR(arm_clk) || IS_ERR(pll1_sys_clk) || IS_ERR(pll1_sw_clk) || |
| IS_ERR(step_clk) || IS_ERR(pll2_pfd2_396m_clk)) { |
| dev_err(cpu_dev, "failed to get clocks\n"); |
| ret = -ENOENT; |
| goto put_node; |
| } |
| |
| arm_reg = devm_regulator_get(cpu_dev, "arm"); |
| pu_reg = devm_regulator_get(cpu_dev, "pu"); |
| soc_reg = devm_regulator_get(cpu_dev, "soc"); |
| if (!arm_reg || !pu_reg || !soc_reg) { |
| dev_err(cpu_dev, "failed to get regulators\n"); |
| ret = -ENOENT; |
| goto put_node; |
| } |
| |
| /* We expect an OPP table supplied by platform */ |
| num = opp_get_opp_count(cpu_dev); |
| if (num < 0) { |
| ret = num; |
| dev_err(cpu_dev, "no OPP table is found: %d\n", ret); |
| goto put_node; |
| } |
| |
| ret = opp_init_cpufreq_table(cpu_dev, &freq_table); |
| if (ret) { |
| dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); |
| goto put_node; |
| } |
| |
| if (of_property_read_u32(np, "clock-latency", &transition_latency)) |
| transition_latency = CPUFREQ_ETERNAL; |
| |
| /* |
| * OPP is maintained in order of increasing frequency, and |
| * freq_table initialised from OPP is therefore sorted in the |
| * same order. |
| */ |
| rcu_read_lock(); |
| opp = opp_find_freq_exact(cpu_dev, |
| freq_table[0].frequency * 1000, true); |
| min_volt = opp_get_voltage(opp); |
| opp = opp_find_freq_exact(cpu_dev, |
| freq_table[--num].frequency * 1000, true); |
| max_volt = opp_get_voltage(opp); |
| rcu_read_unlock(); |
| ret = regulator_set_voltage_time(arm_reg, min_volt, max_volt); |
| if (ret > 0) |
| transition_latency += ret * 1000; |
| |
| /* Count vddpu and vddsoc latency in for 1.2 GHz support */ |
| if (freq_table[num].frequency == FREQ_1P2_GHZ / 1000) { |
| ret = regulator_set_voltage_time(pu_reg, PU_SOC_VOLTAGE_NORMAL, |
| PU_SOC_VOLTAGE_HIGH); |
| if (ret > 0) |
| transition_latency += ret * 1000; |
| ret = regulator_set_voltage_time(soc_reg, PU_SOC_VOLTAGE_NORMAL, |
| PU_SOC_VOLTAGE_HIGH); |
| if (ret > 0) |
| transition_latency += ret * 1000; |
| } |
| |
| ret = cpufreq_register_driver(&imx6q_cpufreq_driver); |
| if (ret) { |
| dev_err(cpu_dev, "failed register driver: %d\n", ret); |
| goto free_freq_table; |
| } |
| |
| of_node_put(np); |
| return 0; |
| |
| free_freq_table: |
| opp_free_cpufreq_table(cpu_dev, &freq_table); |
| put_node: |
| of_node_put(np); |
| return ret; |
| } |
| |
| static int imx6q_cpufreq_remove(struct platform_device *pdev) |
| { |
| cpufreq_unregister_driver(&imx6q_cpufreq_driver); |
| opp_free_cpufreq_table(cpu_dev, &freq_table); |
| |
| return 0; |
| } |
| |
| static struct platform_driver imx6q_cpufreq_platdrv = { |
| .driver = { |
| .name = "imx6q-cpufreq", |
| .owner = THIS_MODULE, |
| }, |
| .probe = imx6q_cpufreq_probe, |
| .remove = imx6q_cpufreq_remove, |
| }; |
| module_platform_driver(imx6q_cpufreq_platdrv); |
| |
| MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); |
| MODULE_DESCRIPTION("Freescale i.MX6Q cpufreq driver"); |
| MODULE_LICENSE("GPL"); |