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Diffstat (limited to 'drivers/cpufreq/imx6q-cpufreq.c')
-rw-r--r--drivers/cpufreq/imx6q-cpufreq.c547
1 files changed, 547 insertions, 0 deletions
diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
new file mode 100644
index 000000000..33728c242
--- /dev/null
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -0,0 +1,547 @@
+// 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;
+
+ 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,
+ .register_em = cpufreq_register_em_with_opp,
+ .name = "imx6q-cpufreq",
+ .attr = cpufreq_generic_attr,
+ .suspend = cpufreq_generic_suspend,
+};
+
+static void imx6x_disable_freq_in_opp(struct device *dev, unsigned long freq)
+{
+ int ret = dev_pm_opp_disable(dev, freq);
+
+ if (ret < 0 && ret != -ENODEV)
+ dev_warn(dev, "failed to disable %ldMHz OPP\n", freq / 1000000);
+}
+
+#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_property_present(dev->of_node, "nvmem-cells")) {
+ 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)
+ imx6x_disable_freq_in_opp(dev, 996000000);
+
+ if (of_machine_is_compatible("fsl,imx6q") ||
+ of_machine_is_compatible("fsl,imx6qp")) {
+ if (val != OCOTP_CFG3_SPEED_852MHZ)
+ imx6x_disable_freq_in_opp(dev, 852000000);
+
+ if (val != OCOTP_CFG3_SPEED_1P2GHZ)
+ imx6x_disable_freq_in_opp(dev, 1200000000);
+ }
+
+ 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_property_present(dev->of_node, "nvmem-cells")) {
+ 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)
+ imx6x_disable_freq_in_opp(dev, 696000000);
+
+ if (of_machine_is_compatible("fsl,imx6ull")) {
+ if (val < OCOTP_CFG3_6ULL_SPEED_792MHZ)
+ imx6x_disable_freq_in_opp(dev, 792000000);
+
+ if (val != OCOTP_CFG3_6ULL_SPEED_900MHZ)
+ imx6x_disable_freq_in_opp(dev, 900000000);
+ }
+
+ 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) {
+ dev_err_probe(cpu_dev, ret, "failed to read ocotp\n");
+ 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 void 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);
+}
+
+static struct platform_driver imx6q_cpufreq_platdrv = {
+ .driver = {
+ .name = "imx6q-cpufreq",
+ },
+ .probe = imx6q_cpufreq_probe,
+ .remove_new = 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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-14 07:27:13 +0000