From b4573d1d657aae28bedf3a9a1f5367e09c80d1d6 Mon Sep 17 00:00:00 2001 From: Anson Huang Date: Thu, 19 Dec 2013 09:16:47 -0500 Subject: [PATCH] cpufreq: imx6q: correct VDDSOC/PU voltage scaling when cpufreq is changed on i.MX6Q, cpu freq change need to follow below flows: 1. each setpoint has different VDDARM, VDDSOC/PU voltage, get the setpoint table from dts; 2. when cpu freq is scaling up, need to increase VDDSOC/PU voltage before VDDARM, if VDDPU is off, no need to change it; 3. when cpu freq is scaling down, need to decrease VDDARM voltage before VDDSOC/PU, if VDDPU is off, no need to change it; normally dts will pass vddsoc/pu freq/volt info to kernel, if not, will use fixed value for vddsoc/pu voltage setting. Signed-off-by: Anson Huang Acked-by: Shawn Guo Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/imx6q-cpufreq.c | 106 +++++++++++++++++++++++++++++----------- 1 file changed, 77 insertions(+), 29 deletions(-) diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c index 4b3f18e..c29198f 100644 --- a/drivers/cpufreq/imx6q-cpufreq.c +++ b/drivers/cpufreq/imx6q-cpufreq.c @@ -35,6 +35,9 @@ static struct device *cpu_dev; static struct cpufreq_frequency_table *freq_table; static unsigned int transition_latency; +static u32 *imx6_soc_volt; +static u32 soc_opp_count; + static unsigned int imx6q_get_speed(unsigned int cpu) { return clk_get_rate(arm_clk) / 1000; @@ -69,23 +72,22 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index) /* scaling up? scale voltage before frequency */ if (new_freq > old_freq) { + 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; } - - /* - * Need to increase vddpu and vddsoc for safety - * if we are about to run at 1.2 GHz. - */ - if (new_freq == 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); - } } /* @@ -120,12 +122,15 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index) "failed to scale vddarm down: %d\n", ret); ret = 0; } - - if (old_freq == 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); + 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; + } + 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; } } @@ -153,6 +158,9 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev) 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) { @@ -201,10 +209,62 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev) goto put_node; } + /* 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 . + */ + 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; + 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. @@ -221,18 +281,6 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev) 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); -- 2.7.4