// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2013 Freescale Semiconductor, Inc. */ #include <linux/clk.h> #include <linux/cpu.h> #include <linux/cpufreq.h> #include <linux/err.h> #include <linux/module.h> #include <linux/nvmem-consumer.h> #include <linux/of.h> #include <linux/of_address.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; enum IMX6_CPUFREQ_CLKS { ARM, PLL1_SYS, STEP, PLL1_SW, PLL2_PFD2_396M, /* MX6UL requires two more clks */ PLL2_BUS, SECONDARY_SEL, }; #define IMX6Q_CPUFREQ_CLK_NUM 5 #define IMX6UL_CPUFREQ_CLK_NUM 7 static int num_clks; static struct clk_bulk_data clks[] = { { .id = "arm" }, { .id = "pll1_sys" }, { .id = "step" }, { .id = "pll1_sw" }, { .id = "pll2_pfd2_396m" }, { .id = "pll2_bus" }, { .id = "secondary_sel" }, }; static struct device *cpu_dev; static struct cpufreq_frequency_table *freq_table; static unsigned int max_freq; 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(clks[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(clks[ARM].clk, (old_freq >> 1) * 1000); clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk); if (freq_hz > clk_get_rate(clks[PLL2_PFD2_396M].clk)) clk_set_parent(clks[SECONDARY_SEL].clk, clks[PLL2_BUS].clk); else clk_set_parent(clks[SECONDARY_SEL].clk, clks[PLL2_PFD2_396M].clk); clk_set_parent(clks[STEP].clk, clks[SECONDARY_SEL].clk); clk_set_parent(clks[PLL1_SW].clk, clks[STEP].clk); if (freq_hz > clk_get_rate(clks[PLL2_BUS].clk)) { clk_set_rate(clks[PLL1_SYS].clk, new_freq * 1000); clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk); } } else { clk_set_parent(clks[STEP].clk, clks[PLL2_PFD2_396M].clk); clk_set_parent(clks[PLL1_SW].clk, clks[STEP].clk); if (freq_hz > clk_get_rate(clks[PLL2_PFD2_396M].clk)) { clk_set_rate(clks[PLL1_SYS].clk, new_freq * 1000); clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk); } else { /* pll1_sys needs to be enabled for divider rate change to work. */ pll1_sys_temp_enabled = true; clk_prepare_enable(clks[PLL1_SYS].clk); } } /* Ensure the arm clock divider is what we expect */ ret = clk_set_rate(clks[ARM].clk, new_freq * 1000); if (ret) { int ret1; dev_err(cpu_dev, "failed to set clock rate: %d\n", ret); ret1 = regulator_set_voltage_tol(arm_reg, volt_old, 0); if (ret1) dev_warn(cpu_dev, "failed to restore vddarm voltage: %d\n", ret1); return ret; } /* PLL1 is only needed until after ARM-PODF is set. */ if (pll1_sys_temp_enabled) clk_disable_unprepare(clks[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 = 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); 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); } } return 0; } static int imx6q_cpufreq_init(struct cpufreq_policy *policy) { policy->clk = clks[ARM].clk; cpufreq_generic_init(policy, freq_table, transition_latency); policy->suspend_freq = max_freq; dev_pm_opp_of_register_em(cpu_dev, policy->cpus); return 0; } static struct cpufreq_driver imx6q_cpufreq_driver = { .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK | CPUFREQ_IS_COOLING_DEV, .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, }; #define OCOTP_CFG3 0x440 #define OCOTP_CFG3_SPEED_SHIFT 16 #define OCOTP_CFG3_SPEED_1P2GHZ 0x3 #define OCOTP_CFG3_SPEED_996MHZ 0x2 #define OCOTP_CFG3_SPEED_852MHZ 0x1 static int imx6q_opp_check_speed_grading(struct device *dev) { struct device_node *np; void __iomem *base; u32 val; int ret; if (of_find_property(dev->of_node, "nvmem-cells", NULL)) { ret = nvmem_cell_read_u32(dev, "speed_grade", &val); if (ret) return ret; } else { np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-ocotp"); if (!np) return -ENOENT; base = of_iomap(np, 0); of_node_put(np); if (!base) { dev_err(dev, "failed to map ocotp\n"); return -EFAULT; } /* * SPEED_GRADING[1:0] defines the max speed of ARM: * 2b'11: 1200000000Hz; * 2b'10: 996000000Hz; * 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz. * 2b'00: 792000000Hz; * We need to set the max speed of ARM according to fuse map. */ val = readl_relaxed(base + OCOTP_CFG3); iounmap(base); } val >>= OCOTP_CFG3_SPEED_SHIFT; val &= 0x3; if (val < OCOTP_CFG3_SPEED_996MHZ) if (dev_pm_opp_disable(dev, 996000000)) dev_warn(dev, "failed to disable 996MHz OPP\n"); if (of_machine_is_compatible("fsl,imx6q") || of_machine_is_compatible("fsl,imx6qp")) { if (val != OCOTP_CFG3_SPEED_852MHZ) if (dev_pm_opp_disable(dev, 852000000)) dev_warn(dev, "failed to disable 852MHz OPP\n"); if (val != OCOTP_CFG3_SPEED_1P2GHZ) if (dev_pm_opp_disable(dev, 1200000000)) dev_warn(dev, "failed to disable 1.2GHz OPP\n"); } return 0; } #define OCOTP_CFG3_6UL_SPEED_696MHZ 0x2 #define OCOTP_CFG3_6ULL_SPEED_792MHZ 0x2 #define OCOTP_CFG3_6ULL_SPEED_900MHZ 0x3 static int imx6ul_opp_check_speed_grading(struct device *dev) { u32 val; int ret = 0; if (of_find_property(dev->of_node, "nvmem-cells", NULL)) { ret = nvmem_cell_read_u32(dev, "speed_grade", &val); if (ret) return ret; } else { struct device_node *np; void __iomem *base; np = of_find_compatible_node(NULL, NULL, "fsl,imx6ul-ocotp"); if (!np) np = of_find_compatible_node(NULL, NULL, "fsl,imx6ull-ocotp"); if (!np) return -ENOENT; base = of_iomap(np, 0); of_node_put(np); if (!base) { dev_err(dev, "failed to map ocotp\n"); return -EFAULT; } val = readl_relaxed(base + OCOTP_CFG3); iounmap(base); } /* * Speed GRADING[1:0] defines the max speed of ARM: * 2b'00: Reserved; * 2b'01: 528000000Hz; * 2b'10: 696000000Hz on i.MX6UL, 792000000Hz on i.MX6ULL; * 2b'11: 900000000Hz on i.MX6ULL only; * We need to set the max speed of ARM according to fuse map. */ val >>= OCOTP_CFG3_SPEED_SHIFT; val &= 0x3; if (of_machine_is_compatible("fsl,imx6ul")) { if (val != OCOTP_CFG3_6UL_SPEED_696MHZ) if (dev_pm_opp_disable(dev, 696000000)) dev_warn(dev, "failed to disable 696MHz OPP\n"); } if (of_machine_is_compatible("fsl,imx6ull")) { if (val != OCOTP_CFG3_6ULL_SPEED_792MHZ) if (dev_pm_opp_disable(dev, 792000000)) dev_warn(dev, "failed to disable 792MHz OPP\n"); if (val != OCOTP_CFG3_6ULL_SPEED_900MHZ) if (dev_pm_opp_disable(dev, 900000000)) dev_warn(dev, "failed to disable 900MHz OPP\n"); } return ret; } 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; } if (of_machine_is_compatible("fsl,imx6ul") || of_machine_is_compatible("fsl,imx6ull")) num_clks = IMX6UL_CPUFREQ_CLK_NUM; else num_clks = IMX6Q_CPUFREQ_CLK_NUM; ret = clk_bulk_get(cpu_dev, num_clks, clks); if (ret) goto put_node; 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; } 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; } if (of_machine_is_compatible("fsl,imx6ul") || of_machine_is_compatible("fsl,imx6ull")) { ret = imx6ul_opp_check_speed_grading(cpu_dev); } else { ret = imx6q_opp_check_speed_grading(cpu_dev); } if (ret) { if (ret != -EPROBE_DEFER) dev_err(cpu_dev, "failed to read ocotp: %d\n", ret); goto out_free_opp; } 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_kcalloc(cpu_dev, num, sizeof(*imx6_soc_volt), 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. */ max_freq = freq_table[--num].frequency; 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, max_freq * 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: 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); clk_bulk_put(num_clks, clks); put_node: of_node_put(np); return ret; } 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); 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_bulk_put(num_clks, clks); return 0; } 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_ALIAS("platform:imx6q-cpufreq"); MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); MODULE_DESCRIPTION("Freescale i.MX6Q cpufreq driver"); MODULE_LICENSE("GPL");