Add cluster regulator support as a preparation to adding generic arm_big_little_dt cpufreq_dt driver support for ODROID-XU3 board. This allows arm_big_little[_dt] driver to set not only the frequency but also the voltage (which is obtained from operating point's voltage value) for CPU clusters.
Cc: Kukjin Kim <kgene....@samsung.com> Cc: Doug Anderson <diand...@chromium.org> Cc: Javier Martinez Canillas <javier.marti...@collabora.co.uk> Cc: Andreas Faerber <afaer...@suse.de> Cc: Sachin Kamat <sachin.ka...@linaro.org> Cc: Thomas Abraham <thomas...@samsung.com> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnier...@samsung.com> --- .../bindings/cpufreq/arm_big_little_dt.txt | 4 + drivers/cpufreq/arm_big_little.c | 153 +++++++++++++++++--- 2 files changed, 139 insertions(+), 18 deletions(-) diff --git a/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt b/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt index 0715695..8ca4a12 100644 --- a/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt +++ b/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt @@ -18,6 +18,10 @@ Required properties: Optional properties: - clock-latency: Specify the possible maximum transition latency for clock, in unit of nanoseconds. +- cpu-cluster.0-supply: Provides the regulator node supplying voltage to CPU + cluster 0. +- cpu-cluster.1-supply: Provides the regulator node supplying voltage to CPU + cluster 1. Examples: diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c index e1a6ba6..edb461b 100644 --- a/drivers/cpufreq/arm_big_little.c +++ b/drivers/cpufreq/arm_big_little.c @@ -31,6 +31,7 @@ #include <linux/slab.h> #include <linux/topology.h> #include <linux/types.h> +#include <linux/regulator/consumer.h> #include <asm/bL_switcher.h> #include "arm_big_little.h" @@ -54,6 +55,9 @@ static bool bL_switching_enabled; static struct cpufreq_arm_bL_ops *arm_bL_ops; static struct clk *clk[MAX_CLUSTERS]; +static struct regulator *reg[MAX_CLUSTERS]; +static struct device *cpu_devs[MAX_CLUSTERS]; +static int transition_latencies[MAX_CLUSTERS]; static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1]; static atomic_t cluster_usage[MAX_CLUSTERS + 1]; @@ -122,7 +126,76 @@ static unsigned int bL_cpufreq_get_rate(unsigned int cpu) } } -static unsigned int +static int +bL_cpufreq_set_rate_cluster(u32 cpu, u32 cluster, u32 new_rate) +{ + unsigned long volt = 0, volt_old = 0; + long freq_Hz; + u32 old_rate; + int ret; + + freq_Hz = new_rate * 1000; + old_rate = clk_get_rate(clk[cluster]) / 1000; + + if (!IS_ERR(reg[cluster])) { + struct dev_pm_opp *opp; + unsigned long opp_freq; + + rcu_read_lock(); + opp = dev_pm_opp_find_freq_ceil(cpu_devs[cluster], &freq_Hz); + if (IS_ERR(opp)) { + rcu_read_unlock(); + pr_err("%s: cpu %d, cluster: %d, failed to find OPP for %ld\n", + __func__, cpu, cluster, freq_Hz); + return PTR_ERR(opp); + } + volt = dev_pm_opp_get_voltage(opp); + opp_freq = dev_pm_opp_get_freq(opp); + rcu_read_unlock(); + volt_old = regulator_get_voltage(reg[cluster]); + pr_debug("%s: cpu %d, cluster: %d, Found OPP: %ld kHz, %ld uV\n", + __func__, cpu, cluster, opp_freq / 1000, volt); + } + + pr_debug("%s: cpu %d, cluster: %d, %u MHz, %ld mV --> %u MHz, %ld mV\n", + __func__, cpu, cluster, + old_rate / 1000, (volt_old > 0) ? volt_old / 1000 : -1, + new_rate / 1000, volt ? volt / 1000 : -1); + + /* scaling up? scale voltage before frequency */ + if (!IS_ERR(reg[cluster]) && new_rate > old_rate) { + ret = regulator_set_voltage_tol(reg[cluster], volt, 0); + if (ret) { + pr_err("%s: cpu: %d, cluster: %d, failed to scale voltage up: %d\n", + __func__, cpu, cluster, ret); + return ret; + } + } + + ret = clk_set_rate(clk[cluster], new_rate * 1000); + if (WARN_ON(ret)) { + pr_err("%s: clk_set_rate failed: %d, cluster: %d\n", + __func__, cluster, ret); + if (!IS_ERR(reg[cluster]) && volt_old > 0) + regulator_set_voltage_tol(reg[cluster], volt_old, 0); + return ret; + } + + /* scaling down? scale voltage after frequency */ + if (!IS_ERR(reg[cluster]) && new_rate < old_rate) { + ret = regulator_set_voltage_tol(reg[cluster], volt, 0); + if (ret) { + pr_err("%s: cpu: %d, cluster: %d, failed to scale voltage down: %d\n", + __func__, cpu, cluster, ret); + clk_set_rate(clk[cluster], old_rate * 1000); + return ret; + } + } + + return 0; +} + +static int bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate) { u32 new_rate, prev_rate; @@ -145,22 +218,17 @@ bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate) pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n", __func__, cpu, old_cluster, new_cluster, new_rate); - ret = clk_set_rate(clk[new_cluster], new_rate * 1000); - if (WARN_ON(ret)) { - pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret, - new_cluster); - if (bLs) { - per_cpu(cpu_last_req_freq, cpu) = prev_rate; - per_cpu(physical_cluster, cpu) = old_cluster; - } - - mutex_unlock(&cluster_lock[new_cluster]); - - return ret; + ret = bL_cpufreq_set_rate_cluster(cpu, new_cluster, new_rate); + if (ret && bLs) { + per_cpu(cpu_last_req_freq, cpu) = prev_rate; + per_cpu(physical_cluster, cpu) = old_cluster; } mutex_unlock(&cluster_lock[new_cluster]); + if (ret) + return ret; + /* Recalc freq for old cluster when switching clusters */ if (old_cluster != new_cluster) { pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n", @@ -174,14 +242,11 @@ bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate) /* Set freq of old cluster if there are cpus left on it */ new_rate = find_cluster_maxfreq(old_cluster); new_rate = ACTUAL_FREQ(old_cluster, new_rate); - if (new_rate) { pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n", __func__, old_cluster, new_rate); - if (clk_set_rate(clk[old_cluster], new_rate * 1000)) - pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n", - __func__, ret, old_cluster); + bL_cpufreq_set_rate_cluster(cpu, old_cluster, new_rate); } mutex_unlock(&cluster_lock[old_cluster]); } @@ -288,6 +353,8 @@ static void _put_cluster_clk_and_freq_table(struct device *cpu_dev) return; clk_put(clk[cluster]); + if (!IS_ERR(reg[cluster])) + regulator_put(reg[cluster]); dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]); if (arm_bL_ops->free_opp_table) arm_bL_ops->free_opp_table(cpu_dev); @@ -321,6 +388,7 @@ static void put_cluster_clk_and_freq_table(struct device *cpu_dev) static int _get_cluster_clk_and_freq_table(struct device *cpu_dev) { + unsigned long min_uV = ~0, max_uV = 0; u32 cluster = raw_cpu_to_cluster(cpu_dev->id); char name[14] = "cpu-cluster."; int ret; @@ -335,6 +403,51 @@ static int _get_cluster_clk_and_freq_table(struct device *cpu_dev) goto out; } + name[12] = cluster + '0'; + reg[cluster] = regulator_get_optional(cpu_dev, name); + if (!IS_ERR(reg[cluster])) { + unsigned long opp_freq = 0; + + dev_dbg(cpu_dev, "%s: reg: %p, cluster: %d\n", + __func__, reg[cluster], cluster); + cpu_devs[cluster] = cpu_dev; + + /* + * Disable any OPPs where the connected regulator isn't able to + * provide the specified voltage and record minimum and maximum + * voltage levels. + */ + while (1) { + struct dev_pm_opp *opp; + unsigned long opp_uV; + + rcu_read_lock(); + opp = dev_pm_opp_find_freq_ceil(cpu_dev, &opp_freq); + if (IS_ERR(opp)) { + rcu_read_unlock(); + break; + } + opp_uV = dev_pm_opp_get_voltage(opp); + rcu_read_unlock(); + + if (regulator_is_supported_voltage(reg[cluster], opp_uV, + opp_uV)) { + if (opp_uV < min_uV) + min_uV = opp_uV; + if (opp_uV > max_uV) + max_uV = opp_uV; + } else { + dev_pm_opp_disable(cpu_dev, opp_freq); + } + + opp_freq++; + } + + ret = regulator_set_voltage_time(reg[cluster], min_uV, max_uV); + if (ret > 0) + transition_latencies[cluster] = ret * 1000; + } + ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]); if (ret) { dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n", @@ -342,7 +455,6 @@ static int _get_cluster_clk_and_freq_table(struct device *cpu_dev) goto free_opp_table; } - name[12] = cluster + '0'; clk[cluster] = clk_get(cpu_dev, name); if (!IS_ERR(clk[cluster])) { dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n", @@ -469,6 +581,11 @@ static int bL_cpufreq_init(struct cpufreq_policy *policy) else policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; + if (cur_cluster < MAX_CLUSTERS && + policy->cpuinfo.transition_latency != CPUFREQ_ETERNAL) + policy->cpuinfo.transition_latency + += transition_latencies[cur_cluster]; + if (is_bL_switching_enabled()) per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html