summaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/Kconfig4
-rw-r--r--drivers/cpufreq/Kconfig.arm6
-rw-r--r--drivers/cpufreq/Makefile2
-rw-r--r--drivers/cpufreq/cpufreq-cpu0.c9
-rw-r--r--drivers/cpufreq/cpufreq.c83
-rw-r--r--drivers/cpufreq/cpufreq_governor.c67
-rw-r--r--drivers/cpufreq/cpufreq_governor.h7
-rw-r--r--drivers/cpufreq/intel_pstate.c46
-rw-r--r--drivers/cpufreq/ppc-corenet-cpufreq.c9
-rw-r--r--drivers/cpufreq/sa1110-cpufreq.c2
-rw-r--r--drivers/cpufreq/tegra-cpufreq.c100
11 files changed, 243 insertions, 92 deletions
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index 1fbe11f2a14..ffe350f86bc 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -185,7 +185,9 @@ config CPU_FREQ_GOV_CONSERVATIVE
config GENERIC_CPUFREQ_CPU0
tristate "Generic CPU0 cpufreq driver"
- depends on HAVE_CLK && REGULATOR && OF && THERMAL && CPU_THERMAL
+ depends on HAVE_CLK && OF
+ # if CPU_THERMAL is on and THERMAL=m, CPU0 cannot be =y:
+ depends on !CPU_THERMAL || THERMAL
select PM_OPP
help
This adds a generic cpufreq driver for CPU0 frequency management.
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 36d20d0fce2..7364a538e05 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -5,8 +5,7 @@
# big LITTLE core layer and glue drivers
config ARM_BIG_LITTLE_CPUFREQ
tristate "Generic ARM big LITTLE CPUfreq driver"
- depends on (BIG_LITTLE && ARM_CPU_TOPOLOGY) || (ARM64 && SMP)
- depends on HAVE_CLK
+ depends on ARM && BIG_LITTLE && ARM_CPU_TOPOLOGY && HAVE_CLK
select PM_OPP
help
This enables the Generic CPUfreq driver for ARM big.LITTLE platforms.
@@ -105,6 +104,7 @@ config ARM_IMX6Q_CPUFREQ
tristate "Freescale i.MX6 cpufreq support"
depends on ARCH_MXC
depends on REGULATOR_ANATOP
+ select PM_OPP
help
This adds cpufreq driver support for Freescale i.MX6 series SoCs.
@@ -119,7 +119,7 @@ config ARM_INTEGRATOR
If in doubt, say Y.
config ARM_KIRKWOOD_CPUFREQ
- def_bool MACH_KIRKWOOD
+ def_bool ARCH_KIRKWOOD || MACH_KIRKWOOD
help
This adds the CPUFreq driver for Marvell Kirkwood
SoCs.
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 738c8b7b17d..db6d9a2fea4 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -49,7 +49,7 @@ obj-$(CONFIG_ARM_BIG_LITTLE_CPUFREQ) += arm_big_little.o
# LITTLE drivers, so that it is probed last.
obj-$(CONFIG_ARM_DT_BL_CPUFREQ) += arm_big_little_dt.o
-obj-$(CONFIG_ARCH_DAVINCI_DA850) += davinci-cpufreq.o
+obj-$(CONFIG_ARCH_DAVINCI) += davinci-cpufreq.o
obj-$(CONFIG_UX500_SOC_DB8500) += dbx500-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS_CPUFREQ) += exynos-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) += exynos4210-cpufreq.o
diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
index 09b9129c7bd..86beda9f950 100644
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ b/drivers/cpufreq/cpufreq-cpu0.c
@@ -104,7 +104,7 @@ static int cpu0_cpufreq_init(struct cpufreq_policy *policy)
}
static struct cpufreq_driver cpu0_cpufreq_driver = {
- .flags = CPUFREQ_STICKY,
+ .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = cpu0_set_target,
.get = cpufreq_generic_get,
@@ -152,11 +152,8 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
goto out_put_reg;
}
- ret = of_init_opp_table(cpu_dev);
- if (ret) {
- pr_err("failed to init OPP table: %d\n", ret);
- goto out_put_clk;
- }
+ /* OPPs might be populated at runtime, don't check for error here */
+ of_init_opp_table(cpu_dev);
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
if (ret) {
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index ae11dd51f81..6f024852c6f 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1153,10 +1153,12 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
* the creation of a brand new one. So we need to perform this update
* by invoking update_policy_cpu().
*/
- if (recover_policy && cpu != policy->cpu)
+ if (recover_policy && cpu != policy->cpu) {
update_policy_cpu(policy, cpu);
- else
+ WARN_ON(kobject_move(&policy->kobj, &dev->kobj));
+ } else {
policy->cpu = cpu;
+ }
cpumask_copy(policy->cpus, cpumask_of(cpu));
@@ -1816,20 +1818,55 @@ EXPORT_SYMBOL(cpufreq_unregister_notifier);
* GOVERNORS *
*********************************************************************/
+/* Must set freqs->new to intermediate frequency */
+static int __target_intermediate(struct cpufreq_policy *policy,
+ struct cpufreq_freqs *freqs, int index)
+{
+ int ret;
+
+ freqs->new = cpufreq_driver->get_intermediate(policy, index);
+
+ /* We don't need to switch to intermediate freq */
+ if (!freqs->new)
+ return 0;
+
+ pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
+ __func__, policy->cpu, freqs->old, freqs->new);
+
+ cpufreq_freq_transition_begin(policy, freqs);
+ ret = cpufreq_driver->target_intermediate(policy, index);
+ cpufreq_freq_transition_end(policy, freqs, ret);
+
+ if (ret)
+ pr_err("%s: Failed to change to intermediate frequency: %d\n",
+ __func__, ret);
+
+ return ret;
+}
+
static int __target_index(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *freq_table, int index)
{
- struct cpufreq_freqs freqs;
+ struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
+ unsigned int intermediate_freq = 0;
int retval = -EINVAL;
bool notify;
notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
-
if (notify) {
- freqs.old = policy->cur;
- freqs.new = freq_table[index].frequency;
- freqs.flags = 0;
+ /* Handle switching to intermediate frequency */
+ if (cpufreq_driver->get_intermediate) {
+ retval = __target_intermediate(policy, &freqs, index);
+ if (retval)
+ return retval;
+
+ intermediate_freq = freqs.new;
+ /* Set old freq to intermediate */
+ if (intermediate_freq)
+ freqs.old = freqs.new;
+ }
+ freqs.new = freq_table[index].frequency;
pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
__func__, policy->cpu, freqs.old, freqs.new);
@@ -1841,9 +1878,23 @@ static int __target_index(struct cpufreq_policy *policy,
pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
retval);
- if (notify)
+ if (notify) {
cpufreq_freq_transition_end(policy, &freqs, retval);
+ /*
+ * Failed after setting to intermediate freq? Driver should have
+ * reverted back to initial frequency and so should we. Check
+ * here for intermediate_freq instead of get_intermediate, in
+ * case we have't switched to intermediate freq at all.
+ */
+ if (unlikely(retval && intermediate_freq)) {
+ freqs.old = intermediate_freq;
+ freqs.new = policy->restore_freq;
+ cpufreq_freq_transition_begin(policy, &freqs);
+ cpufreq_freq_transition_end(policy, &freqs, 0);
+ }
+ }
+
return retval;
}
@@ -1875,6 +1926,9 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
if (target_freq == policy->cur)
return 0;
+ /* Save last value to restore later on errors */
+ policy->restore_freq = policy->cur;
+
if (cpufreq_driver->target)
retval = cpufreq_driver->target(policy, target_freq, relation);
else if (cpufreq_driver->target_index) {
@@ -2190,10 +2244,8 @@ int cpufreq_update_policy(unsigned int cpu)
struct cpufreq_policy new_policy;
int ret;
- if (!policy) {
- ret = -ENODEV;
- goto no_policy;
- }
+ if (!policy)
+ return -ENODEV;
down_write(&policy->rwsem);
@@ -2212,7 +2264,7 @@ int cpufreq_update_policy(unsigned int cpu)
new_policy.cur = cpufreq_driver->get(cpu);
if (WARN_ON(!new_policy.cur)) {
ret = -EIO;
- goto no_policy;
+ goto unlock;
}
if (!policy->cur) {
@@ -2227,10 +2279,10 @@ int cpufreq_update_policy(unsigned int cpu)
ret = cpufreq_set_policy(policy, &new_policy);
+unlock:
up_write(&policy->rwsem);
cpufreq_cpu_put(policy);
-no_policy:
return ret;
}
EXPORT_SYMBOL(cpufreq_update_policy);
@@ -2361,7 +2413,8 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
!(driver_data->setpolicy || driver_data->target_index ||
driver_data->target) ||
(driver_data->setpolicy && (driver_data->target_index ||
- driver_data->target)))
+ driver_data->target)) ||
+ (!!driver_data->get_intermediate != !!driver_data->target_intermediate))
return -EINVAL;
pr_debug("trying to register driver %s\n", driver_data->name);
diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index e1c6433b16e..1b44496b2d2 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -36,14 +36,29 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
struct od_dbs_tuners *od_tuners = dbs_data->tuners;
struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
struct cpufreq_policy *policy;
+ unsigned int sampling_rate;
unsigned int max_load = 0;
unsigned int ignore_nice;
unsigned int j;
- if (dbs_data->cdata->governor == GOV_ONDEMAND)
+ if (dbs_data->cdata->governor == GOV_ONDEMAND) {
+ struct od_cpu_dbs_info_s *od_dbs_info =
+ dbs_data->cdata->get_cpu_dbs_info_s(cpu);
+
+ /*
+ * Sometimes, the ondemand governor uses an additional
+ * multiplier to give long delays. So apply this multiplier to
+ * the 'sampling_rate', so as to keep the wake-up-from-idle
+ * detection logic a bit conservative.
+ */
+ sampling_rate = od_tuners->sampling_rate;
+ sampling_rate *= od_dbs_info->rate_mult;
+
ignore_nice = od_tuners->ignore_nice_load;
- else
+ } else {
+ sampling_rate = cs_tuners->sampling_rate;
ignore_nice = cs_tuners->ignore_nice_load;
+ }
policy = cdbs->cur_policy;
@@ -96,7 +111,46 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
if (unlikely(!wall_time || wall_time < idle_time))
continue;
- load = 100 * (wall_time - idle_time) / wall_time;
+ /*
+ * If the CPU had gone completely idle, and a task just woke up
+ * on this CPU now, it would be unfair to calculate 'load' the
+ * usual way for this elapsed time-window, because it will show
+ * near-zero load, irrespective of how CPU intensive that task
+ * actually is. This is undesirable for latency-sensitive bursty
+ * workloads.
+ *
+ * To avoid this, we reuse the 'load' from the previous
+ * time-window and give this task a chance to start with a
+ * reasonably high CPU frequency. (However, we shouldn't over-do
+ * this copy, lest we get stuck at a high load (high frequency)
+ * for too long, even when the current system load has actually
+ * dropped down. So we perform the copy only once, upon the
+ * first wake-up from idle.)
+ *
+ * Detecting this situation is easy: the governor's deferrable
+ * timer would not have fired during CPU-idle periods. Hence
+ * an unusually large 'wall_time' (as compared to the sampling
+ * rate) indicates this scenario.
+ *
+ * prev_load can be zero in two cases and we must recalculate it
+ * for both cases:
+ * - during long idle intervals
+ * - explicitly set to zero
+ */
+ if (unlikely(wall_time > (2 * sampling_rate) &&
+ j_cdbs->prev_load)) {
+ load = j_cdbs->prev_load;
+
+ /*
+ * Perform a destructive copy, to ensure that we copy
+ * the previous load only once, upon the first wake-up
+ * from idle.
+ */
+ j_cdbs->prev_load = 0;
+ } else {
+ load = 100 * (wall_time - idle_time) / wall_time;
+ j_cdbs->prev_load = load;
+ }
if (load > max_load)
max_load = load;
@@ -318,11 +372,18 @@ int cpufreq_governor_dbs(struct cpufreq_policy *policy,
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_common_info *j_cdbs =
dbs_data->cdata->get_cpu_cdbs(j);
+ unsigned int prev_load;
j_cdbs->cpu = j;
j_cdbs->cur_policy = policy;
j_cdbs->prev_cpu_idle = get_cpu_idle_time(j,
&j_cdbs->prev_cpu_wall, io_busy);
+
+ prev_load = (unsigned int)
+ (j_cdbs->prev_cpu_wall - j_cdbs->prev_cpu_idle);
+ j_cdbs->prev_load = 100 * prev_load /
+ (unsigned int) j_cdbs->prev_cpu_wall;
+
if (ignore_nice)
j_cdbs->prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
diff --git a/drivers/cpufreq/cpufreq_governor.h b/drivers/cpufreq/cpufreq_governor.h
index bfb9ae14142..cc401d147e7 100644
--- a/drivers/cpufreq/cpufreq_governor.h
+++ b/drivers/cpufreq/cpufreq_governor.h
@@ -134,6 +134,13 @@ struct cpu_dbs_common_info {
u64 prev_cpu_idle;
u64 prev_cpu_wall;
u64 prev_cpu_nice;
+ /*
+ * Used to keep track of load in the previous interval. However, when
+ * explicitly set to zero, it is used as a flag to ensure that we copy
+ * the previous load to the current interval only once, upon the first
+ * wake-up from idle.
+ */
+ unsigned int prev_load;
struct cpufreq_policy *cur_policy;
struct delayed_work work;
/*
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index aebd4572eb6..86631cb6f7d 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -128,6 +128,7 @@ static struct pstate_funcs pstate_funcs;
struct perf_limits {
int no_turbo;
+ int turbo_disabled;
int max_perf_pct;
int min_perf_pct;
int32_t max_perf;
@@ -196,10 +197,7 @@ static signed int pid_calc(struct _pid *pid, int32_t busy)
pid->last_err = fp_error;
result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm;
- if (result >= 0)
- result = result + (1 << (FRAC_BITS-1));
- else
- result = result - (1 << (FRAC_BITS-1));
+ result = result + (1 << (FRAC_BITS-1));
return (signed int)fp_toint(result);
}
@@ -290,7 +288,10 @@ static ssize_t store_no_turbo(struct kobject *a, struct attribute *b,
if (ret != 1)
return -EINVAL;
limits.no_turbo = clamp_t(int, input, 0 , 1);
-
+ if (limits.turbo_disabled) {
+ pr_warn("Turbo disabled by BIOS or unavailable on processor\n");
+ limits.no_turbo = limits.turbo_disabled;
+ }
return count;
}
@@ -360,21 +361,21 @@ static int byt_get_min_pstate(void)
{
u64 value;
rdmsrl(BYT_RATIOS, value);
- return (value >> 8) & 0x3F;
+ return (value >> 8) & 0x7F;
}
static int byt_get_max_pstate(void)
{
u64 value;
rdmsrl(BYT_RATIOS, value);
- return (value >> 16) & 0x3F;
+ return (value >> 16) & 0x7F;
}
static int byt_get_turbo_pstate(void)
{
u64 value;
rdmsrl(BYT_TURBO_RATIOS, value);
- return value & 0x3F;
+ return value & 0x7F;
}
static void byt_set_pstate(struct cpudata *cpudata, int pstate)
@@ -384,7 +385,7 @@ static void byt_set_pstate(struct cpudata *cpudata, int pstate)
u32 vid;
val = pstate << 8;
- if (limits.no_turbo)
+ if (limits.no_turbo && !limits.turbo_disabled)
val |= (u64)1 << 32;
vid_fp = cpudata->vid.min + mul_fp(
@@ -408,8 +409,8 @@ static void byt_get_vid(struct cpudata *cpudata)
rdmsrl(BYT_VIDS, value);
- cpudata->vid.min = int_tofp((value >> 8) & 0x3f);
- cpudata->vid.max = int_tofp((value >> 16) & 0x3f);
+ cpudata->vid.min = int_tofp((value >> 8) & 0x7f);
+ cpudata->vid.max = int_tofp((value >> 16) & 0x7f);
cpudata->vid.ratio = div_fp(
cpudata->vid.max - cpudata->vid.min,
int_tofp(cpudata->pstate.max_pstate -
@@ -451,7 +452,7 @@ static void core_set_pstate(struct cpudata *cpudata, int pstate)
u64 val;
val = pstate << 8;
- if (limits.no_turbo)
+ if (limits.no_turbo && !limits.turbo_disabled)
val |= (u64)1 << 32;
wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
@@ -691,23 +692,16 @@ MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
static int intel_pstate_init_cpu(unsigned int cpunum)
{
-
- const struct x86_cpu_id *id;
struct cpudata *cpu;
- id = x86_match_cpu(intel_pstate_cpu_ids);
- if (!id)
- return -ENODEV;
-
all_cpu_data[cpunum] = kzalloc(sizeof(struct cpudata), GFP_KERNEL);
if (!all_cpu_data[cpunum])
return -ENOMEM;
cpu = all_cpu_data[cpunum];
- intel_pstate_get_cpu_pstates(cpu);
-
cpu->cpu = cpunum;
+ intel_pstate_get_cpu_pstates(cpu);
init_timer_deferrable(&cpu->timer);
cpu->timer.function = intel_pstate_timer_func;
@@ -750,7 +744,7 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
limits.min_perf = int_tofp(1);
limits.max_perf_pct = 100;
limits.max_perf = int_tofp(1);
- limits.no_turbo = 0;
+ limits.no_turbo = limits.turbo_disabled;
return 0;
}
limits.min_perf_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
@@ -793,6 +787,7 @@ static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
{
struct cpudata *cpu;
int rc;
+ u64 misc_en;
rc = intel_pstate_init_cpu(policy->cpu);
if (rc)
@@ -800,8 +795,13 @@ static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
cpu = all_cpu_data[policy->cpu];
- if (!limits.no_turbo &&
- limits.min_perf_pct == 100 && limits.max_perf_pct == 100)
+ rdmsrl(MSR_IA32_MISC_ENABLE, misc_en);
+ if (misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE ||
+ cpu->pstate.max_pstate == cpu->pstate.turbo_pstate) {
+ limits.turbo_disabled = 1;
+ limits.no_turbo = 1;
+ }
+ if (limits.min_perf_pct == 100 && limits.max_perf_pct == 100)
policy->policy = CPUFREQ_POLICY_PERFORMANCE;
else
policy->policy = CPUFREQ_POLICY_POWERSAVE;
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c
index 0af618abeba..3607070797a 100644
--- a/drivers/cpufreq/ppc-corenet-cpufreq.c
+++ b/drivers/cpufreq/ppc-corenet-cpufreq.c
@@ -138,7 +138,7 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
struct cpufreq_frequency_table *table;
struct cpu_data *data;
unsigned int cpu = policy->cpu;
- u64 transition_latency_hz;
+ u64 u64temp;
np = of_get_cpu_node(cpu, NULL);
if (!np)
@@ -206,9 +206,10 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
for_each_cpu(i, per_cpu(cpu_mask, cpu))
per_cpu(cpu_data, i) = data;
- transition_latency_hz = 12ULL * NSEC_PER_SEC;
- policy->cpuinfo.transition_latency =
- do_div(transition_latency_hz, fsl_get_sys_freq());
+ /* Minimum transition latency is 12 platform clocks */
+ u64temp = 12ULL * NSEC_PER_SEC;
+ do_div(u64temp, fsl_get_sys_freq());
+ policy->cpuinfo.transition_latency = u64temp + 1;
of_node_put(np);
diff --git a/drivers/cpufreq/sa1110-cpufreq.c b/drivers/cpufreq/sa1110-cpufreq.c
index 546376719d8..b5befc21117 100644
--- a/drivers/cpufreq/sa1110-cpufreq.c
+++ b/drivers/cpufreq/sa1110-cpufreq.c
@@ -349,7 +349,7 @@ static int __init sa1110_clk_init(void)
name = "K4S641632D";
if (machine_is_h3100())
name = "KM416S4030CT";
- if (machine_is_jornada720())
+ if (machine_is_jornada720() || machine_is_h3600())
name = "K4S281632B-1H";
if (machine_is_nanoengine())
name = "MT48LC8M16A2TG-75";
diff --git a/drivers/cpufreq/tegra-cpufreq.c b/drivers/cpufreq/tegra-cpufreq.c
index 6e774c6ac20..8084c7f7e20 100644
--- a/drivers/cpufreq/tegra-cpufreq.c
+++ b/drivers/cpufreq/tegra-cpufreq.c
@@ -45,46 +45,54 @@ static struct clk *cpu_clk;
static struct clk *pll_x_clk;
static struct clk *pll_p_clk;
static struct clk *emc_clk;
+static bool pll_x_prepared;
-static int tegra_cpu_clk_set_rate(unsigned long rate)
+static unsigned int tegra_get_intermediate(struct cpufreq_policy *policy,
+ unsigned int index)
+{
+ unsigned int ifreq = clk_get_rate(pll_p_clk) / 1000;
+
+ /*
+ * Don't switch to intermediate freq if:
+ * - we are already at it, i.e. policy->cur == ifreq
+ * - index corresponds to ifreq
+ */
+ if ((freq_table[index].frequency == ifreq) || (policy->cur == ifreq))
+ return 0;
+
+ return ifreq;
+}
+
+static int tegra_target_intermediate(struct cpufreq_policy *policy,
+ unsigned int index)
{
int ret;
/*
* Take an extra reference to the main pll so it doesn't turn
- * off when we move the cpu off of it
+ * off when we move the cpu off of it as enabling it again while we
+ * switch to it from tegra_target() would take additional time.
+ *
+ * When target-freq is equal to intermediate freq we don't need to
+ * switch to an intermediate freq and so this routine isn't called.
+ * Also, we wouldn't be using pll_x anymore and must not take extra
+ * reference to it, as it can be disabled now to save some power.
*/
clk_prepare_enable(pll_x_clk);
ret = clk_set_parent(cpu_clk, pll_p_clk);
- if (ret) {
- pr_err("Failed to switch cpu to clock pll_p\n");
- goto out;
- }
-
- if (rate == clk_get_rate(pll_p_clk))
- goto out;
-
- ret = clk_set_rate(pll_x_clk, rate);
- if (ret) {
- pr_err("Failed to change pll_x to %lu\n", rate);
- goto out;
- }
-
- ret = clk_set_parent(cpu_clk, pll_x_clk);
- if (ret) {
- pr_err("Failed to switch cpu to clock pll_x\n");
- goto out;
- }
+ if (ret)
+ clk_disable_unprepare(pll_x_clk);
+ else
+ pll_x_prepared = true;
-out:
- clk_disable_unprepare(pll_x_clk);
return ret;
}
static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
{
unsigned long rate = freq_table[index].frequency;
+ unsigned int ifreq = clk_get_rate(pll_p_clk) / 1000;
int ret = 0;
/*
@@ -98,10 +106,30 @@ static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
else
clk_set_rate(emc_clk, 100000000); /* emc 50Mhz */
- ret = tegra_cpu_clk_set_rate(rate * 1000);
+ /*
+ * target freq == pll_p, don't need to take extra reference to pll_x_clk
+ * as it isn't used anymore.
+ */
+ if (rate == ifreq)
+ return clk_set_parent(cpu_clk, pll_p_clk);
+
+ ret = clk_set_rate(pll_x_clk, rate * 1000);
+ /* Restore to earlier frequency on error, i.e. pll_x */
if (ret)
- pr_err("cpu-tegra: Failed to set cpu frequency to %lu kHz\n",
- rate);
+ pr_err("Failed to change pll_x to %lu\n", rate);
+
+ ret = clk_set_parent(cpu_clk, pll_x_clk);
+ /* This shouldn't fail while changing or restoring */
+ WARN_ON(ret);
+
+ /*
+ * Drop count to pll_x clock only if we switched to intermediate freq
+ * earlier while transitioning to a target frequency.
+ */
+ if (pll_x_prepared) {
+ clk_disable_unprepare(pll_x_clk);
+ pll_x_prepared = false;
+ }
return ret;
}
@@ -137,16 +165,18 @@ static int tegra_cpu_exit(struct cpufreq_policy *policy)
}
static struct cpufreq_driver tegra_cpufreq_driver = {
- .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
- .verify = cpufreq_generic_frequency_table_verify,
- .target_index = tegra_target,
- .get = cpufreq_generic_get,
- .init = tegra_cpu_init,
- .exit = tegra_cpu_exit,
- .name = "tegra",
- .attr = cpufreq_generic_attr,
+ .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+ .verify = cpufreq_generic_frequency_table_verify,
+ .get_intermediate = tegra_get_intermediate,
+ .target_intermediate = tegra_target_intermediate,
+ .target_index = tegra_target,
+ .get = cpufreq_generic_get,
+ .init = tegra_cpu_init,
+ .exit = tegra_cpu_exit,
+ .name = "tegra",
+ .attr = cpufreq_generic_attr,
#ifdef CONFIG_PM
- .suspend = cpufreq_generic_suspend,
+ .suspend = cpufreq_generic_suspend,
#endif
};
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-28 06:29:22 +0000