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Release 4.14 drivers/cpufreq/imx6q-cpufreq.c

Directory: drivers/cpufreq
/*
 * 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/cpu.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pm_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;

/* clk used by i.MX6UL */

static struct clk *pll2_bus_clk;

static struct clk *secondary_sel_clk;


static struct device *cpu_dev;

static bool free_opp;

static struct cpufreq_frequency_table *freq_table;

static unsigned int transition_latency;


static u32 *imx6_soc_volt;

static u32 soc_opp_count;


static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index) { struct dev_pm_opp *opp; unsigned long freq_hz, volt, volt_old; unsigned int old_freq, new_freq; bool pll1_sys_temp_enabled = false; int ret; new_freq = freq_table[index].frequency; freq_hz = new_freq * 1000; old_freq = clk_get_rate(arm_clk) / 1000; opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz); if (IS_ERR(opp)) { dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_hz); return PTR_ERR(opp); } volt = dev_pm_opp_get_voltage(opp); dev_pm_opp_put(opp); volt_old = regulator_get_voltage(arm_reg); dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n", old_freq / 1000, volt_old / 1000, new_freq / 1000, volt / 1000); /* scaling up? scale voltage before frequency */ if (new_freq > old_freq) { if (!IS_ERR(pu_reg)) { ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0); if (ret) { dev_err(cpu_dev, "failed to scale vddpu up: %d\n", ret); return ret; } } ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0); if (ret) { dev_err(cpu_dev, "failed to scale vddsoc up: %d\n", ret); return ret; } 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; } } /* * 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. * For i.MX6UL, it has a secondary clk mux, the cpu frequency change * flow is slightly different from other i.MX6 OSC. * The cpu frequeny change flow for i.MX6(except i.MX6UL) 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 */ if (of_machine_is_compatible("fsl,imx6ul") || of_machine_is_compatible("fsl,imx6ull")) { /* * When changing pll1_sw_clk's parent to pll1_sys_clk, * CPU may run at higher than 528MHz, this will lead to * the system unstable if the voltage is lower than the * voltage of 528MHz, so lower the CPU frequency to one * half before changing CPU frequency. */ clk_set_rate(arm_clk, (old_freq >> 1) * 1000); clk_set_parent(pll1_sw_clk, pll1_sys_clk); if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) clk_set_parent(secondary_sel_clk, pll2_bus_clk); else clk_set_parent(secondary_sel_clk, pll2_pfd2_396m_clk); clk_set_parent(step_clk, secondary_sel_clk); clk_set_parent(pll1_sw_clk, step_clk); } else { 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, new_freq * 1000); clk_set_parent(pll1_sw_clk, pll1_sys_clk); } else { /* pll1_sys needs to be enabled for divider rate change to work. */ pll1_sys_temp_enabled = true; clk_prepare_enable(pll1_sys_clk); } } /* Ensure the arm clock divider is what we expect */ ret = clk_set_rate(arm_clk, new_freq * 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; } /* PLL1 is only needed until after ARM-PODF is set. */ if (pll1_sys_temp_enabled) clk_disable_unprepare(pll1_sys_clk); /* scaling down? scale voltage after frequency */ if (new_freq < old_freq) { ret = regulator_set_voltage_tol(arm_reg, volt, 0); if (ret) { dev_warn(cpu_dev, "failed to scale vddarm down: %d\n", ret); ret = 0; } ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0); if (ret) { dev_warn(cpu_dev, "failed to scale vddsoc down: %d\n", ret); ret = 0; } if (!IS_ERR(pu_reg)) { ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0); if (ret) { dev_warn(cpu_dev, "failed to scale vddpu down: %d\n", ret); ret = 0; } } } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Shawn Guo29152.72%18.33%
Anson Huang11821.38%216.67%
Bai Ping7213.04%18.33%
Viresh Kumar356.34%433.33%
Leonard Crestez285.07%18.33%
Octavian Purdila50.91%18.33%
Nishanth Menon30.54%216.67%
Total552100.00%12100.00%


static int imx6q_cpufreq_init(struct cpufreq_policy *policy) { int ret; policy->clk = arm_clk; ret = cpufreq_generic_init(policy, freq_table, transition_latency); policy->suspend_freq = policy->max; return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Shawn Guo1945.24%125.00%
Leonard Crestez1638.10%125.00%
Viresh Kumar716.67%250.00%
Total42100.00%4100.00%

static struct cpufreq_driver imx6q_cpufreq_driver = { .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK, .verify = cpufreq_generic_frequency_table_verify, .target_index = imx6q_set_target, .get = cpufreq_generic_get, .init = imx6q_cpufreq_init, .name = "imx6q-cpufreq", .attr = cpufreq_generic_attr, .suspend = cpufreq_generic_suspend, };
static int imx6q_cpufreq_probe(struct platform_device *pdev) { struct device_node *np; struct dev_pm_opp *opp; unsigned long min_volt, max_volt; int num, ret; const struct property *prop; const __be32 *val; u32 nr, i, j; cpu_dev = get_cpu_device(0); if (!cpu_dev) { pr_err("failed to get cpu0 device\n"); return -ENODEV; } np = of_node_get(cpu_dev->of_node); if (!np) { dev_err(cpu_dev, "failed to find cpu0 node\n"); return -ENOENT; } arm_clk = clk_get(cpu_dev, "arm"); pll1_sys_clk = clk_get(cpu_dev, "pll1_sys"); pll1_sw_clk = clk_get(cpu_dev, "pll1_sw"); step_clk = clk_get(cpu_dev, "step"); pll2_pfd2_396m_clk = 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_clk; } if (of_machine_is_compatible("fsl,imx6ul") || of_machine_is_compatible("fsl,imx6ull")) { pll2_bus_clk = clk_get(cpu_dev, "pll2_bus"); secondary_sel_clk = clk_get(cpu_dev, "secondary_sel"); if (IS_ERR(pll2_bus_clk) || IS_ERR(secondary_sel_clk)) { dev_err(cpu_dev, "failed to get clocks specific to imx6ul\n"); ret = -ENOENT; goto put_clk; } } arm_reg = regulator_get(cpu_dev, "arm"); pu_reg = regulator_get_optional(cpu_dev, "pu"); soc_reg = regulator_get(cpu_dev, "soc"); if (PTR_ERR(arm_reg) == -EPROBE_DEFER || PTR_ERR(soc_reg) == -EPROBE_DEFER || PTR_ERR(pu_reg) == -EPROBE_DEFER) { ret = -EPROBE_DEFER; dev_dbg(cpu_dev, "regulators not ready, defer\n"); goto put_reg; } if (IS_ERR(arm_reg) || IS_ERR(soc_reg)) { dev_err(cpu_dev, "failed to get regulators\n"); ret = -ENOENT; goto put_reg; } /* * We expect an OPP table supplied by platform. * Just, incase the platform did not supply the OPP * table, it will try to get it. */ num = dev_pm_opp_get_opp_count(cpu_dev); if (num < 0) { ret = dev_pm_opp_of_add_table(cpu_dev); if (ret < 0) { dev_err(cpu_dev, "failed to init OPP table: %d\n", ret); goto put_reg; } /* Because we have added the OPPs here, we must free them */ free_opp = true; num = dev_pm_opp_get_opp_count(cpu_dev); if (num < 0) { ret = num; dev_err(cpu_dev, "no OPP table is found: %d\n", ret); goto out_free_opp; } } ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); if (ret) { dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); goto out_free_opp; } /* Make imx6_soc_volt array's size same as arm opp number */ imx6_soc_volt = devm_kzalloc(cpu_dev, sizeof(*imx6_soc_volt) * num, GFP_KERNEL); if (imx6_soc_volt == NULL) { ret = -ENOMEM; goto free_freq_table; } prop = of_find_property(np, "fsl,soc-operating-points", NULL); if (!prop || !prop->value) goto soc_opp_out; /* * Each OPP is a set of tuples consisting of frequency and * voltage like <freq-kHz vol-uV>. */ nr = prop->length / sizeof(u32); if (nr % 2 || (nr / 2) < num) goto soc_opp_out; for (j = 0; j < num; j++) { val = prop->value; for (i = 0; i < nr / 2; i++) { unsigned long freq = be32_to_cpup(val++); unsigned long volt = be32_to_cpup(val++); if (freq_table[j].frequency == freq) { imx6_soc_volt[soc_opp_count++] = volt; break; } } } soc_opp_out: /* use fixed soc opp volt if no valid soc opp info found in dtb */ if (soc_opp_count != num) { dev_warn(cpu_dev, "can NOT find valid fsl,soc-operating-points property in dtb, use default value!\n"); for (j = 0; j < num; j++) imx6_soc_volt[j] = PU_SOC_VOLTAGE_NORMAL; if (freq_table[num - 1].frequency * 1000 == FREQ_1P2_GHZ) imx6_soc_volt[num - 1] = PU_SOC_VOLTAGE_HIGH; } if (of_property_read_u32(np, "clock-latency", &transition_latency)) transition_latency = CPUFREQ_ETERNAL; /* * Calculate the ramp time for max voltage change in the * VDDSOC and VDDPU regulators. */ ret = regulator_set_voltage_time(soc_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]); if (ret > 0) transition_latency += ret * 1000; if (!IS_ERR(pu_reg)) { ret = regulator_set_voltage_time(pu_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]); if (ret > 0) transition_latency += ret * 1000; } /* * OPP is maintained in order of increasing frequency, and * freq_table initialised from OPP is therefore sorted in the * same order. */ opp = dev_pm_opp_find_freq_exact(cpu_dev, freq_table[0].frequency * 1000, true); min_volt = dev_pm_opp_get_voltage(opp); dev_pm_opp_put(opp); opp = dev_pm_opp_find_freq_exact(cpu_dev, freq_table[--num].frequency * 1000, true); max_volt = dev_pm_opp_get_voltage(opp); dev_pm_opp_put(opp); ret = regulator_set_voltage_time(arm_reg, min_volt, max_volt); 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: dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); out_free_opp: if (free_opp) dev_pm_opp_of_remove_table(cpu_dev); put_reg: if (!IS_ERR(arm_reg)) regulator_put(arm_reg); if (!IS_ERR(pu_reg)) regulator_put(pu_reg); if (!IS_ERR(soc_reg)) regulator_put(soc_reg); put_clk: if (!IS_ERR(arm_clk)) clk_put(arm_clk); if (!IS_ERR(pll1_sys_clk)) clk_put(pll1_sys_clk); if (!IS_ERR(pll1_sw_clk)) clk_put(pll1_sw_clk); if (!IS_ERR(step_clk)) clk_put(step_clk); if (!IS_ERR(pll2_pfd2_396m_clk)) clk_put(pll2_pfd2_396m_clk); if (!IS_ERR(pll2_bus_clk)) clk_put(pll2_bus_clk); if (!IS_ERR(secondary_sel_clk)) clk_put(secondary_sel_clk); of_node_put(np); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Shawn Guo38136.08%15.88%
Anson Huang32130.40%211.76%
Philipp Zabel11711.08%15.88%
Bai Ping827.77%15.88%
Irina Tirdea434.07%15.88%
John Tobias413.88%15.88%
Viresh Kumar272.56%317.65%
Sudeep KarkadaNagesha242.27%211.76%
Nishanth Menon80.76%211.76%
Wei Yongjun60.57%15.88%
Octavian Purdila50.47%15.88%
Christophe Jaillet10.09%15.88%
Total1056100.00%17100.00%


static int imx6q_cpufreq_remove(struct platform_device *pdev) { cpufreq_unregister_driver(&imx6q_cpufreq_driver); dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); if (free_opp) dev_pm_opp_of_remove_table(cpu_dev); regulator_put(arm_reg); if (!IS_ERR(pu_reg)) regulator_put(pu_reg); regulator_put(soc_reg); clk_put(arm_clk); clk_put(pll1_sys_clk); clk_put(pll1_sw_clk); clk_put(step_clk); clk_put(pll2_pfd2_396m_clk); clk_put(pll2_bus_clk); clk_put(secondary_sel_clk); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Philipp Zabel4042.11%114.29%
Shawn Guo2728.42%114.29%
Bai Ping1010.53%114.29%
Viresh Kumar99.47%228.57%
Anson Huang88.42%114.29%
Nishanth Menon11.05%114.29%
Total95100.00%7100.00%

static struct platform_driver imx6q_cpufreq_platdrv = { .driver = { .name = "imx6q-cpufreq", }, .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");

Overall Contributors

PersonTokensPropCommitsCommitProp
Shawn Guo89945.63%13.70%
Anson Huang45623.15%27.41%
Bai Ping1778.98%13.70%
Philipp Zabel1577.97%13.70%
Viresh Kumar914.62%1037.04%
Leonard Crestez492.49%27.41%
Irina Tirdea432.18%13.70%
John Tobias412.08%13.70%
Sudeep KarkadaNagesha271.37%27.41%
Nishanth Menon130.66%311.11%
Octavian Purdila100.51%13.70%
Wei Yongjun60.30%13.70%
Christophe Jaillet10.05%13.70%
Total1970100.00%27100.00%
Directory: drivers/cpufreq
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