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path: root/drivers/cpufreq/tegra194-cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/tegra194-cpufreq.c')
-rw-r--r--drivers/cpufreq/tegra194-cpufreq.c72
1 files changed, 55 insertions, 17 deletions
diff --git a/drivers/cpufreq/tegra194-cpufreq.c b/drivers/cpufreq/tegra194-cpufreq.c
index e1d931c457a7..6a67f36f3b80 100644
--- a/drivers/cpufreq/tegra194-cpufreq.c
+++ b/drivers/cpufreq/tegra194-cpufreq.c
@@ -21,7 +21,6 @@
#define KHZ 1000
#define REF_CLK_MHZ 408 /* 408 MHz */
#define US_DELAY 500
-#define US_DELAY_MIN 2
#define CPUFREQ_TBL_STEP_HZ (50 * KHZ * KHZ)
#define MAX_CNT ~0U
@@ -44,7 +43,6 @@ struct tegra194_cpufreq_data {
struct tegra_cpu_ctr {
u32 cpu;
- u32 delay;
u32 coreclk_cnt, last_coreclk_cnt;
u32 refclk_cnt, last_refclk_cnt;
};
@@ -112,7 +110,7 @@ static void tegra_read_counters(struct work_struct *work)
val = read_freq_feedback();
c->last_refclk_cnt = lower_32_bits(val);
c->last_coreclk_cnt = upper_32_bits(val);
- udelay(c->delay);
+ udelay(US_DELAY);
val = read_freq_feedback();
c->refclk_cnt = lower_32_bits(val);
c->coreclk_cnt = upper_32_bits(val);
@@ -139,7 +137,7 @@ static void tegra_read_counters(struct work_struct *work)
* @cpu - logical cpu whose freq to be updated
* Returns freq in KHz on success, 0 if cpu is offline
*/
-static unsigned int tegra194_get_speed_common(u32 cpu, u32 delay)
+static unsigned int tegra194_calculate_speed(u32 cpu)
{
struct read_counters_work read_counters_work;
struct tegra_cpu_ctr c;
@@ -153,7 +151,6 @@ static unsigned int tegra194_get_speed_common(u32 cpu, u32 delay)
* interrupts enabled.
*/
read_counters_work.c.cpu = cpu;
- read_counters_work.c.delay = delay;
INIT_WORK_ONSTACK(&read_counters_work.work, tegra_read_counters);
queue_work_on(cpu, read_counters_wq, &read_counters_work.work);
flush_work(&read_counters_work.work);
@@ -180,9 +177,61 @@ static unsigned int tegra194_get_speed_common(u32 cpu, u32 delay)
return (rate_mhz * KHZ); /* in KHz */
}
+static void get_cpu_ndiv(void *ndiv)
+{
+ u64 ndiv_val;
+
+ asm volatile("mrs %0, s3_0_c15_c0_4" : "=r" (ndiv_val) : );
+
+ *(u64 *)ndiv = ndiv_val;
+}
+
+static void set_cpu_ndiv(void *data)
+{
+ struct cpufreq_frequency_table *tbl = data;
+ u64 ndiv_val = (u64)tbl->driver_data;
+
+ asm volatile("msr s3_0_c15_c0_4, %0" : : "r" (ndiv_val));
+}
+
static unsigned int tegra194_get_speed(u32 cpu)
{
- return tegra194_get_speed_common(cpu, US_DELAY);
+ struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
+ struct cpufreq_frequency_table *pos;
+ unsigned int rate;
+ u64 ndiv;
+ int ret;
+ u32 cl;
+
+ smp_call_function_single(cpu, get_cpu_cluster, &cl, true);
+
+ /* reconstruct actual cpu freq using counters */
+ rate = tegra194_calculate_speed(cpu);
+
+ /* get last written ndiv value */
+ ret = smp_call_function_single(cpu, get_cpu_ndiv, &ndiv, true);
+ if (WARN_ON_ONCE(ret))
+ return rate;
+
+ /*
+ * If the reconstructed frequency has acceptable delta from
+ * the last written value, then return freq corresponding
+ * to the last written ndiv value from freq_table. This is
+ * done to return consistent value.
+ */
+ cpufreq_for_each_valid_entry(pos, data->tables[cl]) {
+ if (pos->driver_data != ndiv)
+ continue;
+
+ if (abs(pos->frequency - rate) > 115200) {
+ pr_warn("cpufreq: cpu%d,cur:%u,set:%u,set ndiv:%llu\n",
+ cpu, rate, pos->frequency, ndiv);
+ } else {
+ rate = pos->frequency;
+ }
+ break;
+ }
+ return rate;
}
static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
@@ -196,9 +245,6 @@ static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
if (cl >= data->num_clusters)
return -EINVAL;
- /* boot freq */
- policy->cur = tegra194_get_speed_common(policy->cpu, US_DELAY_MIN);
-
/* set same policy for all cpus in a cluster */
for (cpu = (cl * 2); cpu < ((cl + 1) * 2); cpu++)
cpumask_set_cpu(cpu, policy->cpus);
@@ -209,14 +255,6 @@ static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
return 0;
}
-static void set_cpu_ndiv(void *data)
-{
- struct cpufreq_frequency_table *tbl = data;
- u64 ndiv_val = (u64)tbl->driver_data;
-
- asm volatile("msr s3_0_c15_c0_4, %0" : : "r" (ndiv_val));
-}
-
static int tegra194_cpufreq_set_target(struct cpufreq_policy *policy,
unsigned int index)
{