Afzal Mohammed <[email protected]> writes:

> 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 <[email protected]>
> Cc: Sekhar Nori <[email protected]>
> Signed-off-by: Afzal Mohammed <[email protected]>

Thanks, will queue this with the CPUfreq changes for MPU DVFS.

Kevin

> ---
> Hi,
>
> Tolerance specified here is that of AM335X, least value
> of tolerance that I could find so far for OMAP family
>
> This applies on top of Kevin Hilman's patch (v2),
> "cpufreq: OMAP: scale voltage along with frequency"
> http://www.spinics.net/lists/linux-omap/msg65002.html
>
> Regards
> Afzal
>
>  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 10b8e23..3cea51b 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__);
--
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