On Tue, Dec 17, 2013 at 05:08:22PM -0500, Anson Huang wrote:
> 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 <b20788@xxxxxxxxxxxxx>
> ---
> drivers/cpufreq/imx6q-cpufreq.c | 117 +++++++++++++++++++++++++++++----------
> 1 file changed, 88 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
> index 4b3f18e..65c1df1 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 +72,24 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
>
> /* scaling up? scale voltage before frequency */
> if (new_freq > old_freq) {
> + if (regulator_is_enabled(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;
> }
> -
> - /*
> - * 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 +124,17 @@ 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;
> + }
> + if (regulator_is_enabled(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;
> + }
> }
> }
>
> @@ -153,6 +162,9 @@ 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 +213,69 @@ 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) {
> + dev_warn(cpu_dev, "No valid memory for imx6_soc_volt!\n");
Drop this message. Error code -ENOMEM is enough to tell what's going
wrong.
> + ret = -ENOMEM;
> + goto free_freq_table;
> + }
> +
> + prop = of_find_property(np, "fsl,soc-operating-points", NULL);
> + if (!prop || !prop->value) {
> + dev_warn(cpu_dev, "No valid fsl,soc-operating-points property is found!\n");
> + 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) {
> + dev_warn(cpu_dev, "Invalid fsl,soc-operating-points list!\n");
> + goto soc_opp_out;
> + }
> +
> + rcu_read_lock();
You do not need this lock any more.
> + 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;
> + }
> + }
> + }
> + rcu_read_unlock();
> +
> +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 soc opp info in dtb, use default value!\n");
It will be a little noisy for old DTB case with print so many warnings.
Maybe we should drop above two dev_warn() in fsl,soc-operating-points
property check and do once here.
> + 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(soc_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
One of the regulator_set_voltage_time() should be for pu_reg.
Shawn
> + 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 +292,6 @@ 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);
> --
> 1.7.9.5
>
>
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