diff options
| author | Afzal Mohammed <afzal@ti.com> | 2012-02-23 14:49:24 +0100 |
|---|---|---|
| committer | Kevin Hilman <khilman@ti.com> | 2012-03-02 22:55:57 +0100 |
| commit | 42daffd2d6c665716d442d518022ecaad17ddf64 (patch) | |
| tree | 7caa90a291f0c9eea522cafe2f6a7b419fb71438 /drivers/cpufreq | |
| parent | cpufreq: OMAP: scale voltage along with frequency (diff) | |
| download | linux-42daffd2d6c665716d442d518022ecaad17ddf64.tar.xz linux-42daffd2d6c665716d442d518022ecaad17ddf64.zip | |
cpufreq: OMAP: specify range for voltage scaling
Specify voltage in ranges for regulator. Range
used is tolerance specified for OPP.
This helps to achieve DVFS with a wider range of
regulators.
Cc: Kevin Hilman <khilman@ti.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Afzal Mohammed <afzal@ti.com>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/omap-cpufreq.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c index 9f5d6368766e..67bbb06d0460 100644 --- a/drivers/cpufreq/omap-cpufreq.c +++ b/drivers/cpufreq/omap-cpufreq.c @@ -38,6 +38,9 @@ #include <mach/hardware.h> +/* OPP tolerance in percentage */ +#define OPP_TOLERANCE 4 + #ifdef CONFIG_SMP struct lpj_info { unsigned long ref; @@ -81,7 +84,7 @@ static int omap_target(struct cpufreq_policy *policy, int r, ret = 0; struct cpufreq_freqs freqs; struct opp *opp; - unsigned long freq, volt = 0, volt_old = 0; + unsigned long freq, volt = 0, volt_old = 0, tol = 0; if (!freq_table) { dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__, @@ -125,6 +128,7 @@ static int omap_target(struct cpufreq_policy *policy, return -EINVAL; } volt = opp_get_voltage(opp); + tol = volt * OPP_TOLERANCE / 100; volt_old = regulator_get_voltage(mpu_reg); } @@ -134,7 +138,7 @@ static int omap_target(struct cpufreq_policy *policy, /* scaling up? scale voltage before frequency */ if (mpu_reg && (freqs.new > freqs.old)) { - r = regulator_set_voltage(mpu_reg, volt, volt); + r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol); if (r < 0) { dev_warn(mpu_dev, "%s: unable to scale voltage up.\n", __func__); @@ -147,7 +151,7 @@ static int omap_target(struct cpufreq_policy *policy, /* scaling down? scale voltage after frequency */ if (mpu_reg && (freqs.new < freqs.old)) { - r = regulator_set_voltage(mpu_reg, volt, volt); + r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol); if (r < 0) { dev_warn(mpu_dev, "%s: unable to scale voltage down.\n", __func__); |