On Wed, Oct 23, 2019 at 12:37:03PM +0530, Kiran Gunda wrote: > The auto string detection algorithm checks if the current WLED > sink configuration is valid. It tries enabling every sink and > checks if the OVP fault is observed. Based on this information > it detects and enables the valid sink configuration. > Auto calibration will be triggered when the OVP fault interrupts > are seen frequently thereby it tries to fix the sink configuration. > > The auto-detection also kicks in when the connected LED string > of the display-backlight malfunctions (because of damage) and > requires the damaged string to be turned off to prevent the > complete panel and/or board from being damaged. > > Signed-off-by: Kiran Gunda <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]> > --- > drivers/video/backlight/qcom-wled.c | 400 > +++++++++++++++++++++++++++++++++++- > 1 file changed, 394 insertions(+), 6 deletions(-) > > diff --git a/drivers/video/backlight/qcom-wled.c > b/drivers/video/backlight/qcom-wled.c > index 658b1e0..33b6007 100644 > --- a/drivers/video/backlight/qcom-wled.c > +++ b/drivers/video/backlight/qcom-wled.c > @@ -17,19 +17,29 @@ > #define WLED_MAX_STRINGS 4 > > #define WLED_DEFAULT_BRIGHTNESS 2048 > - > +#define WLED_SOFT_START_DLY_US 10000 > #define WLED3_SINK_REG_BRIGHT_MAX 0xFFF > > /* WLED3/WLED4 control registers */ > +#define WLED3_CTRL_REG_FAULT_STATUS 0x08 > +#define WLED3_CTRL_REG_ILIM_FAULT_BIT BIT(0) > +#define WLED3_CTRL_REG_OVP_FAULT_BIT BIT(1) > +#define WLED4_CTRL_REG_SC_FAULT_BIT BIT(2) > + > +#define WLED3_CTRL_REG_INT_RT_STS 0x10 > +#define WLED3_CTRL_REG_OVP_FAULT_STATUS BIT(1) > + > #define WLED3_CTRL_REG_MOD_EN 0x46 > #define WLED3_CTRL_REG_MOD_EN_MASK BIT(7) > #define WLED3_CTRL_REG_MOD_EN_SHIFT 7 > > +#define WLED3_CTRL_REG_FEEDBACK_CONTROL 0x48 > + > #define WLED3_CTRL_REG_FREQ 0x4c > #define WLED3_CTRL_REG_FREQ_MASK GENMASK(3, 0) > > #define WLED3_CTRL_REG_OVP 0x4d > -#define WLED3_CTRL_REG_OVP_MASK GENMASK(1, 0) > +#define WLED3_CTRL_REG_OVP_MASK GENMASK(1, 0) > > #define WLED3_CTRL_REG_ILIMIT 0x4e > #define WLED3_CTRL_REG_ILIMIT_MASK GENMASK(2, 0) > @@ -119,6 +129,7 @@ struct wled_config { > bool ext_gen; > bool cabc; > bool external_pfet; > + bool auto_detection_enabled; > }; > > struct wled { > @@ -127,17 +138,22 @@ struct wled { > struct regmap *regmap; > struct mutex lock; /* Lock to avoid race from thread irq handler */ > ktime_t last_short_event; > + ktime_t start_ovp_fault_time; > u16 ctrl_addr; > u16 sink_addr; > u16 max_string_count; > + u16 auto_detection_ovp_count; > u32 brightness; > u32 max_brightness; > u32 short_count; > + u32 auto_detect_count; > bool disabled_by_short; > bool has_short_detect; > int short_irq; > + int ovp_irq; > > struct wled_config cfg; > + struct delayed_work ovp_work; > int (*wled_set_brightness)(struct wled *wled, u16 brightness); > }; > > @@ -182,6 +198,13 @@ static int wled4_set_brightness(struct wled *wled, u16 > brightness) > return 0; > } > > +static void wled_ovp_work(struct work_struct *work) > +{ > + struct wled *wled = container_of(work, > + struct wled, ovp_work.work); > + enable_irq(wled->ovp_irq); > +} > + > static int wled_module_enable(struct wled *wled, int val) > { > int rc; > @@ -193,7 +216,25 @@ static int wled_module_enable(struct wled *wled, int val) > WLED3_CTRL_REG_MOD_EN, > WLED3_CTRL_REG_MOD_EN_MASK, > val << WLED3_CTRL_REG_MOD_EN_SHIFT); > - return rc; > + if (rc < 0) > + return rc; > + > + if (wled->ovp_irq > 0) { > + if (val) { > + /* > + * The hardware generates a storm of spurious OVP > + * interrupts during soft start operations. So defer > + * enabling the IRQ for 10ms to ensure that the > + * soft start is complete. > + */ > + schedule_delayed_work(&wled->ovp_work, HZ / 100); > + } else { > + if (!cancel_delayed_work_sync(&wled->ovp_work)) > + disable_irq(wled->ovp_irq); > + } > + } > + > + return 0; > } > > static int wled_sync_toggle(struct wled *wled) > @@ -300,6 +341,304 @@ static irqreturn_t wled_short_irq_handler(int irq, void > *_wled) > return IRQ_HANDLED; > } > > +#define AUTO_DETECT_BRIGHTNESS 200 > + > +static void wled_auto_string_detection(struct wled *wled) > +{ > + int rc = 0, i; > + u32 sink_config = 0, int_sts; > + u8 sink_test = 0, sink_valid = 0, val; > + > + /* Read configured sink configuration */ > + rc = regmap_read(wled->regmap, wled->sink_addr + > + WLED4_SINK_REG_CURR_SINK, &sink_config); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to read SINK configuration rc=%d\n", > + rc); > + goto failed_detect; > + } > + > + /* Disable the module before starting detection */ > + rc = regmap_update_bits(wled->regmap, > + wled->ctrl_addr + WLED3_CTRL_REG_MOD_EN, > + WLED3_CTRL_REG_MOD_EN_MASK, 0); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to disable WLED module rc=%d\n", rc); > + goto failed_detect; > + } > + > + /* Set low brightness across all sinks */ > + rc = wled4_set_brightness(wled, AUTO_DETECT_BRIGHTNESS); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to set brightness for auto detection > rc=%d\n", > + rc); > + goto failed_detect; > + } > + > + if (wled->cfg.cabc) { > + for (i = 0; i < wled->cfg.num_strings; i++) { > + rc = regmap_update_bits(wled->regmap, wled->sink_addr + > + WLED4_SINK_REG_STR_CABC(i), > + WLED4_SINK_REG_STR_CABC_MASK, > + 0); > + if (rc < 0) > + goto failed_detect; > + } > + } > + > + /* Disable all sinks */ > + rc = regmap_write(wled->regmap, > + wled->sink_addr + WLED4_SINK_REG_CURR_SINK, 0); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to disable all sinks rc=%d\n", rc); > + goto failed_detect; > + } > + > + /* Iterate through the strings one by one */ > + for (i = 0; i < wled->cfg.num_strings; i++) { > + sink_test = BIT((WLED4_SINK_REG_CURR_SINK_SHFT + i)); > + > + /* Enable feedback control */ > + rc = regmap_write(wled->regmap, wled->ctrl_addr + > + WLED3_CTRL_REG_FEEDBACK_CONTROL, i + 1); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to enable feedback for SINK > %d rc = %d\n", > + i + 1, rc); > + goto failed_detect; > + } > + > + /* Enable the sink */ > + rc = regmap_write(wled->regmap, wled->sink_addr + > + WLED4_SINK_REG_CURR_SINK, sink_test); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to configure SINK %d > rc=%d\n", > + i + 1, rc); > + goto failed_detect; > + } > + > + /* Enable the module */ > + rc = regmap_update_bits(wled->regmap, wled->ctrl_addr + > + WLED3_CTRL_REG_MOD_EN, > + WLED3_CTRL_REG_MOD_EN_MASK, > + WLED3_CTRL_REG_MOD_EN_MASK); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to enable WLED module > rc=%d\n", > + rc); > + goto failed_detect; > + } > + > + usleep_range(WLED_SOFT_START_DLY_US, > + WLED_SOFT_START_DLY_US + 1000); > + > + rc = regmap_read(wled->regmap, wled->ctrl_addr + > + WLED3_CTRL_REG_INT_RT_STS, &int_sts); > + if (rc < 0) { > + dev_err(wled->dev, "Error in reading > WLED3_CTRL_INT_RT_STS rc=%d\n", > + rc); > + goto failed_detect; > + } > + > + if (int_sts & WLED3_CTRL_REG_OVP_FAULT_STATUS) > + dev_dbg(wled->dev, "WLED OVP fault detected with SINK > %d\n", > + i + 1); > + else > + sink_valid |= sink_test; > + > + /* Disable the module */ > + rc = regmap_update_bits(wled->regmap, > + wled->ctrl_addr + WLED3_CTRL_REG_MOD_EN, > + WLED3_CTRL_REG_MOD_EN_MASK, 0); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to disable WLED module > rc=%d\n", > + rc); > + goto failed_detect; > + } > + } > + > + if (!sink_valid) { > + dev_err(wled->dev, "No valid WLED sinks found\n"); > + wled->disabled_by_short = true; > + goto failed_detect; > + } > + > + if (sink_valid != sink_config) { > + dev_warn(wled->dev, "%x is not a valid sink configuration - > using %x instead\n", > + sink_config, sink_valid); > + sink_config = sink_valid; > + } > + > + /* Write the new sink configuration */ > + rc = regmap_write(wled->regmap, > + wled->sink_addr + WLED4_SINK_REG_CURR_SINK, > + sink_config); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to reconfigure the default sink > rc=%d\n", > + rc); > + goto failed_detect; > + } > + > + /* Enable valid sinks */ > + for (i = 0; i < wled->cfg.num_strings; i++) { > + if (wled->cfg.cabc) { > + rc = regmap_update_bits(wled->regmap, wled->sink_addr + > + WLED4_SINK_REG_STR_CABC(i), > + WLED4_SINK_REG_STR_CABC_MASK, > + WLED4_SINK_REG_STR_CABC_MASK); > + if (rc < 0) > + goto failed_detect; > + } > + > + if (sink_config & BIT(WLED4_SINK_REG_CURR_SINK_SHFT + i)) > + val = WLED4_SINK_REG_STR_MOD_MASK; > + else > + val = 0x0; /* Disable modulator_en for unused sink */ > + > + rc = regmap_write(wled->regmap, wled->sink_addr + > + WLED4_SINK_REG_STR_MOD_EN(i), val); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to configure MODULATOR_EN > rc=%d\n", > + rc); > + goto failed_detect; > + } > + } > + > + /* Restore the feedback setting */ > + rc = regmap_write(wled->regmap, > + wled->ctrl_addr + WLED3_CTRL_REG_FEEDBACK_CONTROL, 0); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to restore feedback setting rc=%d\n", > + rc); > + goto failed_detect; > + } > + > + /* Restore brightness */ > + rc = wled4_set_brightness(wled, wled->brightness); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to set brightness after auto > detection rc=%d\n", > + rc); > + goto failed_detect; > + } > + > + rc = regmap_update_bits(wled->regmap, > + wled->ctrl_addr + WLED3_CTRL_REG_MOD_EN, > + WLED3_CTRL_REG_MOD_EN_MASK, > + WLED3_CTRL_REG_MOD_EN_MASK); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to enable WLED module rc=%d\n", rc); > + goto failed_detect; > + } > + > +failed_detect: > + return; > +} > + > +#define WLED_AUTO_DETECT_OVP_COUNT 5 > +#define WLED_AUTO_DETECT_CNT_DLY_US USEC_PER_SEC > +static bool wled_auto_detection_required(struct wled *wled) > +{ > + s64 elapsed_time_us; > + > + if (!wled->cfg.auto_detection_enabled) > + return false; > + > + /* > + * Check if the OVP fault was an occasional one > + * or if it's firing continuously, the latter qualifies > + * for an auto-detection check. > + */ > + if (!wled->auto_detection_ovp_count) { > + wled->start_ovp_fault_time = ktime_get(); > + wled->auto_detection_ovp_count++; > + } else { > + elapsed_time_us = ktime_us_delta(ktime_get(), > + wled->start_ovp_fault_time); > + if (elapsed_time_us > WLED_AUTO_DETECT_CNT_DLY_US) > + wled->auto_detection_ovp_count = 0; > + else > + wled->auto_detection_ovp_count++; > + > + if (wled->auto_detection_ovp_count >= > + WLED_AUTO_DETECT_OVP_COUNT) { > + wled->auto_detection_ovp_count = 0; > + return true; > + } > + } > + > + return false; > +} > + > +static int wled_auto_detection_at_init(struct wled *wled) > +{ > + int rc; > + u32 fault_status, rt_status; > + > + if (!wled->cfg.auto_detection_enabled) > + return 0; > + > + rc = regmap_read(wled->regmap, > + wled->ctrl_addr + WLED3_CTRL_REG_INT_RT_STS, > + &rt_status); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to read RT status rc=%d\n", rc); > + return rc; > + } > + > + rc = regmap_read(wled->regmap, > + wled->ctrl_addr + WLED3_CTRL_REG_FAULT_STATUS, > + &fault_status); > + if (rc < 0) { > + dev_err(wled->dev, "Failed to read fault status rc=%d\n", rc); > + return rc; > + } > + > + if ((rt_status & WLED3_CTRL_REG_OVP_FAULT_STATUS) || > + (fault_status & WLED3_CTRL_REG_OVP_FAULT_BIT)) { > + mutex_lock(&wled->lock); > + wled_auto_string_detection(wled); > + mutex_unlock(&wled->lock); > + } > + > + return rc; > +} > + > +static irqreturn_t wled_ovp_irq_handler(int irq, void *_wled) > +{ > + struct wled *wled = _wled; > + int rc; > + u32 int_sts, fault_sts; > + > + rc = regmap_read(wled->regmap, > + wled->ctrl_addr + WLED3_CTRL_REG_INT_RT_STS, &int_sts); > + if (rc < 0) { > + dev_err(wled->dev, "Error in reading WLED3_INT_RT_STS rc=%d\n", > + rc); > + return IRQ_HANDLED; > + } > + > + rc = regmap_read(wled->regmap, wled->ctrl_addr + > + WLED3_CTRL_REG_FAULT_STATUS, &fault_sts); > + if (rc < 0) { > + dev_err(wled->dev, "Error in reading WLED_FAULT_STATUS rc=%d\n", > + rc); > + return IRQ_HANDLED; > + } > + > + if (fault_sts & (WLED3_CTRL_REG_OVP_FAULT_BIT | > + WLED3_CTRL_REG_ILIM_FAULT_BIT)) > + dev_dbg(wled->dev, "WLED OVP fault detected, int_sts=%x > fault_sts= %x\n", > + int_sts, fault_sts); > + > + if (fault_sts & WLED3_CTRL_REG_OVP_FAULT_BIT) { > + if (wled_auto_detection_required(wled)) { > + mutex_lock(&wled->lock); > + wled_auto_string_detection(wled); > + mutex_unlock(&wled->lock); > + } > + } > + > + return IRQ_HANDLED; > +} > + > static int wled3_setup(struct wled *wled) > { > u16 addr; > @@ -436,8 +775,10 @@ static int wled4_setup(struct wled *wled) > sink_en |= 1 << temp; > } > > - if (sink_cfg == sink_en) > - return 0; > + if (sink_cfg == sink_en) { > + rc = wled_auto_detection_at_init(wled); > + return rc; > + } > > rc = regmap_update_bits(wled->regmap, > wled->sink_addr + WLED4_SINK_REG_CURR_SINK, > @@ -500,7 +841,9 @@ static int wled4_setup(struct wled *wled) > return rc; > } > > - return 0; > + rc = wled_auto_detection_at_init(wled); > + > + return rc; > } > > static const struct wled_config wled4_config_defaults = { > @@ -511,6 +854,7 @@ static int wled4_setup(struct wled *wled) > .switch_freq = 11, > .cabc = false, > .external_pfet = false, > + .auto_detection_enabled = false, > }; > > static const u32 wled3_boost_i_limit_values[] = { > @@ -677,6 +1021,7 @@ static int wled_configure(struct wled *wled, int version) > { "qcom,ext-gen", &cfg->ext_gen, }, > { "qcom,cabc", &cfg->cabc, }, > { "qcom,external-pfet", &cfg->external_pfet, }, > + { "qcom,auto-string-detection", &cfg->auto_detection_enabled, }, > }; > > prop_addr = of_get_address(dev->of_node, 0, NULL, NULL); > @@ -797,6 +1142,40 @@ static int wled_configure_short_irq(struct wled *wled, > return rc; > } > > +static int wled_configure_ovp_irq(struct wled *wled, > + struct platform_device *pdev) > +{ > + int rc; > + u32 val; > + > + wled->ovp_irq = platform_get_irq_byname(pdev, "ovp"); > + if (wled->ovp_irq < 0) { > + dev_dbg(&pdev->dev, "OVP IRQ not found - disabling automatic > string detection\n"); > + return 0; > + } > + > + rc = devm_request_threaded_irq(wled->dev, wled->ovp_irq, NULL, > + wled_ovp_irq_handler, IRQF_ONESHOT, > + "wled_ovp_irq", wled); > + if (rc < 0) { > + dev_err(wled->dev, "Unable to request ovp_irq (err:%d)\n", > + rc); > + wled->ovp_irq = 0; > + return 0; > + } > + > + rc = regmap_read(wled->regmap, wled->ctrl_addr + > + WLED3_CTRL_REG_MOD_EN, &val); > + if (rc < 0) > + return rc; > + > + /* Keep OVP irq disabled until module is enabled */ > + if (!(val & WLED3_CTRL_REG_MOD_EN_MASK)) > + disable_irq(wled->ovp_irq); > + > + return 0; > +} > + > static const struct backlight_ops wled_ops = { > .update_status = wled_update_status, > }; > @@ -837,6 +1216,7 @@ static int wled_probe(struct platform_device *pdev) > > switch (version) { > case 3: > + wled->cfg.auto_detection_enabled = false; > rc = wled3_setup(wled); > if (rc) { > dev_err(&pdev->dev, "wled3_setup failed\n"); > @@ -858,10 +1238,16 @@ static int wled_probe(struct platform_device *pdev) > break; > } > > + INIT_DELAYED_WORK(&wled->ovp_work, wled_ovp_work); > + > rc = wled_configure_short_irq(wled, pdev); > if (rc < 0) > return rc; > > + rc = wled_configure_ovp_irq(wled, pdev); > + if (rc < 0) > + return rc; > + > val = WLED_DEFAULT_BRIGHTNESS; > of_property_read_u32(pdev->dev.of_node, "default-brightness", &val); > > @@ -880,7 +1266,9 @@ static int wled_remove(struct platform_device *pdev) > struct wled *wled = dev_get_drvdata(&pdev->dev); > > mutex_destroy(&wled->lock); > + cancel_delayed_work_sync(&wled->ovp_work); > disable_irq(wled->short_irq); > + disable_irq(wled->ovp_irq); > > return 0; > } > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project > _______________________________________________ dri-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/dri-devel
