From e9a90d046b9c9fe8f7c8efefe7b0e64c3c0daa8f Mon Sep 17 00:00:00 2001 From: Keerthy Date: Wed, 22 Apr 2015 18:21:42 +0530 Subject: [PATCH] thermal: ti-soc-thermal: OMAP5: Implement Workaround for Errata i813 DESCRIPTION Spurious Thermal Alert: Talert can happen randomly while the device remains under the temperature limit defined for this event to trig. This spurious event is caused by a incorrect re-synchronization between clock domains. The comparison between configured threshold and current temperature value can happen while the value is transitioning (metastable), thus causing inappropriate event generation. No spurious event occurs as long as the threshold value stays unchanged. Spurious event can be generated while a thermal alert threshold is modified in CONTROL_BANDGAP_THRESHOLD_MPU/GPU/CORE/DSPEVE/IVA_n. WORKAROUND Spurious event generation can be avoided by performing following sequence when the threshold is modified: 1. Mask the hot/cold events at the thermal IP level. 2. Modify Threshold. 3. Unmask the hot/cold events at the thermal IP level. Signed-off-by: Keerthy Signed-off-by: Eduardo Valentin --- .../ti-soc-thermal/omap5-thermal-data.c | 3 +- drivers/thermal/ti-soc-thermal/ti-bandgap.c | 41 ++++++++++++++++++- drivers/thermal/ti-soc-thermal/ti-bandgap.h | 4 +- 3 files changed, 45 insertions(+), 3 deletions(-) diff --git a/drivers/thermal/ti-soc-thermal/omap5-thermal-data.c b/drivers/thermal/ti-soc-thermal/omap5-thermal-data.c index eff0c80fd4af..79ff70c446ba 100644 --- a/drivers/thermal/ti-soc-thermal/omap5-thermal-data.c +++ b/drivers/thermal/ti-soc-thermal/omap5-thermal-data.c @@ -319,7 +319,8 @@ const struct ti_bandgap_data omap5430_data = { TI_BANDGAP_FEATURE_FREEZE_BIT | TI_BANDGAP_FEATURE_TALERT | TI_BANDGAP_FEATURE_COUNTER_DELAY | - TI_BANDGAP_FEATURE_HISTORY_BUFFER, + TI_BANDGAP_FEATURE_HISTORY_BUFFER | + TI_BANDGAP_FEATURE_ERRATA_813, .fclock_name = "l3instr_ts_gclk_div", .div_ck_name = "l3instr_ts_gclk_div", .conv_table = omap5430_adc_to_temp, diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.c b/drivers/thermal/ti-soc-thermal/ti-bandgap.c index 9747523858a1..bc14dc874594 100644 --- a/drivers/thermal/ti-soc-thermal/ti-bandgap.c +++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.c @@ -445,7 +445,7 @@ static int ti_bandgap_update_alert_threshold(struct ti_bandgap *bgp, int id, { struct temp_sensor_data *ts_data = bgp->conf->sensors[id].ts_data; struct temp_sensor_registers *tsr; - u32 thresh_val, reg_val, t_hot, t_cold; + u32 thresh_val, reg_val, t_hot, t_cold, ctrl; int err = 0; tsr = bgp->conf->sensors[id].registers; @@ -477,8 +477,47 @@ static int ti_bandgap_update_alert_threshold(struct ti_bandgap *bgp, int id, ~(tsr->threshold_thot_mask | tsr->threshold_tcold_mask); reg_val |= (t_hot << __ffs(tsr->threshold_thot_mask)) | (t_cold << __ffs(tsr->threshold_tcold_mask)); + + /** + * Errata i813: + * Spurious Thermal Alert: Talert can happen randomly while the device + * remains under the temperature limit defined for this event to trig. + * This spurious event is caused by a incorrect re-synchronization + * between clock domains. The comparison between configured threshold + * and current temperature value can happen while the value is + * transitioning (metastable), thus causing inappropriate event + * generation. No spurious event occurs as long as the threshold value + * stays unchanged. Spurious event can be generated while a thermal + * alert threshold is modified in + * CONTROL_BANDGAP_THRESHOLD_MPU/GPU/CORE/DSPEVE/IVA_n. + */ + + if (TI_BANDGAP_HAS(bgp, ERRATA_813)) { + /* Mask t_hot and t_cold events at the IP Level */ + ctrl = ti_bandgap_readl(bgp, tsr->bgap_mask_ctrl); + + if (hot) + ctrl &= ~tsr->mask_hot_mask; + else + ctrl &= ~tsr->mask_cold_mask; + + ti_bandgap_writel(bgp, ctrl, tsr->bgap_mask_ctrl); + } + + /* Write the threshold value */ ti_bandgap_writel(bgp, reg_val, tsr->bgap_threshold); + if (TI_BANDGAP_HAS(bgp, ERRATA_813)) { + /* Unmask t_hot and t_cold events at the IP Level */ + ctrl = ti_bandgap_readl(bgp, tsr->bgap_mask_ctrl); + if (hot) + ctrl |= tsr->mask_hot_mask; + else + ctrl |= tsr->mask_cold_mask; + + ti_bandgap_writel(bgp, ctrl, tsr->bgap_mask_ctrl); + } + if (err) { dev_err(bgp->dev, "failed to reprogram thot threshold\n"); err = -EIO; diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.h b/drivers/thermal/ti-soc-thermal/ti-bandgap.h index b2da3fc42b51..0c52f7afba00 100644 --- a/drivers/thermal/ti-soc-thermal/ti-bandgap.h +++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.h @@ -320,7 +320,8 @@ struct ti_temp_sensor { * * TI_BANDGAP_FEATURE_ERRATA_814 - used to workaorund when the bandgap device * has Errata 814 - * + * TI_BANDGAP_FEATURE_ERRATA_813 - used to workaorund when the bandgap device + * has Errata 813 * TI_BANDGAP_HAS(b, f) - macro to check if a bandgap device is capable of a * specific feature (above) or not. Return non-zero, if yes. */ @@ -335,6 +336,7 @@ struct ti_temp_sensor { #define TI_BANDGAP_FEATURE_COUNTER_DELAY BIT(8) #define TI_BANDGAP_FEATURE_HISTORY_BUFFER BIT(9) #define TI_BANDGAP_FEATURE_ERRATA_814 BIT(10) +#define TI_BANDGAP_FEATURE_ERRATA_813 BIT(11) #define TI_BANDGAP_HAS(b, f) \ ((b)->conf->features & TI_BANDGAP_FEATURE_ ## f)