diff options
| -rw-r--r-- | arch/arm/mach-omap2/smartreflex-class1p5.c | 40 |
1 files changed, 35 insertions, 5 deletions
diff --git a/arch/arm/mach-omap2/smartreflex-class1p5.c b/arch/arm/mach-omap2/smartreflex-class1p5.c index b2b16eae6a2..ea9915b891d 100644 --- a/arch/arm/mach-omap2/smartreflex-class1p5.c +++ b/arch/arm/mach-omap2/smartreflex-class1p5.c @@ -34,7 +34,7 @@ #define MAX_VDDS 3 #define SR1P5_SAMPLING_DELAY_MS 1 -#define SR1P5_STABLE_SAMPLES 5 +#define SR1P5_STABLE_SAMPLES 10 #define SR1P5_MAX_TRIGGERS 5 /* @@ -50,6 +50,9 @@ * @vdata: voltage data we are calibrating * @num_calib_triggers: number of triggers from calibration loop * @num_osc_samples: number of samples collected by isr + * @u_volt_samples: private data for collecting voltage samples in + * case oscillations. filled by the notifier and + * consumed by the work item. * @work_active: have we scheduled a work item? */ struct sr_class1p5_work_data { @@ -58,6 +61,7 @@ struct sr_class1p5_work_data { struct omap_volt_data *vdata; u8 num_calib_triggers; u8 num_osc_samples; + unsigned long u_volt_samples[SR1P5_STABLE_SAMPLES]; bool work_active; }; @@ -138,6 +142,7 @@ static int sr_class1p5_notify(struct voltagedomain *voltdm, u32 status) vp->common->ops->clear_txdone(vp->id); idx = (work_data->num_osc_samples) % SR1P5_STABLE_SAMPLES; + work_data->u_volt_samples[idx] = omap_vp_get_curr_volt(voltdm); work_data->num_osc_samples++; return 0; @@ -162,7 +167,7 @@ static void do_calibrate(struct work_struct *work) struct omap_volt_data *volt_data; struct voltagedomain *voltdm; struct omap_vp_instance *vp; - int timeout = 0; + int timeout = 0, idx = 0; work_data = container_of(work, struct sr_class1p5_work_data, work.work); @@ -245,11 +250,36 @@ start_sampling: return; oscillating_calib: - /* Use the nominal voltage as the safe voltage */ - u_volt_safe = volt_data->volt_nominal; - /* pick up current voltage to switch if needed */ + /* + * We are here for Oscillations due to two scenarios: + * a) SR is attempting to adjust voltage lower than VLIMITO + * which VP will ignore, but SR will re-attempt + * b) actual oscillations + * NOTE: For debugging, enable debug to see the samples. + */ + pr_warning("%s: %s Stop sampling: Voltage Nominal=%d samples=%d\n", + __func__, work_data->voltdm->name, + volt_data->volt_nominal, work_data->num_osc_samples); + + /* pick up current voltage */ u_volt_current = omap_vp_get_curr_volt(voltdm); + /* Just in case we got more interrupts than our tiny buffer */ + if (work_data->num_osc_samples > SR1P5_STABLE_SAMPLES) + idx = SR1P5_STABLE_SAMPLES; + else + idx = work_data->num_osc_samples; + /* Index at 0 */ + idx -= 1; + u_volt_safe = u_volt_current; + /* Grab the max of the samples as the stable voltage */ + for (; idx >= 0; idx--) { + pr_debug("%s: osc_v[%d]=%ld, safe_v=%ld\n", __func__, idx, + work_data->u_volt_samples[idx], u_volt_safe); + if (work_data->u_volt_samples[idx] > u_volt_safe) + u_volt_safe = work_data->u_volt_samples[idx]; + } + /* Fall through to close up common stuff */ done_calib: omap_vp_disable(voltdm); |