[PATCH V6 2/4] backlight: qcom-wled: Add callback functions

From: Kiran Gunda
Date: Thu Apr 23 2020 - 11:34:40 EST


Add wled_cabc_config, wled_sync_toggle, wled_ovp_fault_status
and wled_ovp_delay and wled_auto_detection_required callback
functions to prepare the driver for adding WLED5 support.

Signed-off-by: Kiran Gunda <kgunda@xxxxxxxxxxxxxx>
Signed-off-by: Subbaraman Narayanamurthy <subbaram@xxxxxxxxxxxxxx>
Reviewed-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
---
drivers/video/backlight/qcom-wled.c | 213 ++++++++++++++++++++++++------------
1 file changed, 141 insertions(+), 72 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index df53fbd..7b0095e 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -147,6 +147,7 @@ struct wled {
u32 max_brightness;
u32 short_count;
u32 auto_detect_count;
+ u32 version;
bool disabled_by_short;
bool has_short_detect;
int short_irq;
@@ -154,7 +155,30 @@ struct wled {

struct wled_config cfg;
struct delayed_work ovp_work;
+
+ /* Configures the brightness. Applicable for wled3, wled4 and wled5 */
int (*wled_set_brightness)(struct wled *wled, u16 brightness);
+
+ /* Configures the cabc register. Applicable for wled4 and wled5 */
+ int (*wled_cabc_config)(struct wled *wled, bool enable);
+
+ /*
+ * Toggles the sync bit for the brightness update to take place.
+ * Applicable for WLED3, WLED4 and WLED5.
+ */
+ int (*wled_sync_toggle)(struct wled *wled);
+
+ /*
+ * Time to wait before checking the OVP status after wled module enable.
+ * Applicable for WLED4 and WLED5.
+ */
+ int (*wled_ovp_delay)(struct wled *wled);
+
+ /*
+ * Determines if the auto string detection is required.
+ * Applicable for WLED4 and WLED5
+ */
+ bool (*wled_auto_detection_required)(struct wled *wled);
};

static int wled3_set_brightness(struct wled *wled, u16 brightness)
@@ -237,7 +261,7 @@ static int wled_module_enable(struct wled *wled, int val)
return 0;
}

-static int wled_sync_toggle(struct wled *wled)
+static int wled3_sync_toggle(struct wled *wled)
{
int rc;
unsigned int mask = GENMASK(wled->max_string_count - 1, 0);
@@ -255,6 +279,46 @@ static int wled_sync_toggle(struct wled *wled)
return rc;
}

+static int wled_ovp_fault_status(struct wled *wled, bool *fault_set)
+{
+ int rc;
+ u32 int_rt_sts, fault_sts;
+
+ *fault_set = false;
+ rc = regmap_read(wled->regmap,
+ wled->ctrl_addr + WLED3_CTRL_REG_INT_RT_STS,
+ &int_rt_sts);
+ if (rc < 0) {
+ dev_err(wled->dev, "Failed to read INT_RT_STS rc=%d\n", rc);
+ return rc;
+ }
+
+ rc = regmap_read(wled->regmap,
+ wled->ctrl_addr + WLED3_CTRL_REG_FAULT_STATUS,
+ &fault_sts);
+ if (rc < 0) {
+ dev_err(wled->dev, "Failed to read FAULT_STATUS rc=%d\n", rc);
+ return rc;
+ }
+
+ if (int_rt_sts & WLED3_CTRL_REG_OVP_FAULT_STATUS)
+ *fault_set = true;
+
+ if (fault_sts & WLED3_CTRL_REG_OVP_FAULT_BIT)
+ *fault_set = true;
+
+ if (*fault_set)
+ dev_dbg(wled->dev, "WLED OVP fault detected, int_rt_sts=0x%x fault_sts=0x%x\n",
+ int_rt_sts, fault_sts);
+
+ return rc;
+}
+
+static int wled4_ovp_delay(struct wled *wled)
+{
+ return WLED_SOFT_START_DLY_US;
+}
+
static int wled_update_status(struct backlight_device *bl)
{
struct wled *wled = bl_get_data(bl);
@@ -275,7 +339,7 @@ static int wled_update_status(struct backlight_device *bl)
goto unlock_mutex;
}

- rc = wled_sync_toggle(wled);
+ rc = wled->wled_sync_toggle(wled);
if (rc < 0) {
dev_err(wled->dev, "wled sync failed rc:%d\n", rc);
goto unlock_mutex;
@@ -298,6 +362,25 @@ static int wled_update_status(struct backlight_device *bl)
return rc;
}

+static int wled4_cabc_config(struct wled *wled, bool enable)
+{
+ int i, j, rc;
+ u8 val;
+
+ for (i = 0; i < wled->cfg.num_strings; i++) {
+ j = wled->cfg.enabled_strings[i];
+
+ val = enable ? WLED4_SINK_REG_STR_CABC_MASK : 0;
+ rc = regmap_update_bits(wled->regmap, wled->sink_addr +
+ WLED4_SINK_REG_STR_CABC(j),
+ WLED4_SINK_REG_STR_CABC_MASK, val);
+ if (rc < 0)
+ return rc;
+ }
+
+ return 0;
+}
+
#define WLED_SHORT_DLY_MS 20
#define WLED_SHORT_CNT_MAX 5
#define WLED_SHORT_RESET_CNT_DLY_US USEC_PER_SEC
@@ -345,9 +428,10 @@ static irqreturn_t wled_short_irq_handler(int irq, void *_wled)

static void wled_auto_string_detection(struct wled *wled)
{
- int rc = 0, i;
- u32 sink_config = 0, int_sts;
+ int rc = 0, i, delay_time_us;
+ u32 sink_config = 0;
u8 sink_test = 0, sink_valid = 0, val;
+ bool fault_set;

/* Read configured sink configuration */
rc = regmap_read(wled->regmap, wled->sink_addr +
@@ -376,14 +460,9 @@ static void wled_auto_string_detection(struct wled *wled)
}

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;
- }
+ rc = wled->wled_cabc_config(wled, false);
+ if (rc < 0)
+ goto failed_detect;
}

/* Disable all sinks */
@@ -427,18 +506,17 @@ static void wled_auto_string_detection(struct wled *wled)
goto failed_detect;
}

- usleep_range(WLED_SOFT_START_DLY_US,
- WLED_SOFT_START_DLY_US + 1000);
+ delay_time_us = wled->wled_ovp_delay(wled);
+ usleep_range(delay_time_us, delay_time_us + 1000);

- rc = regmap_read(wled->regmap, wled->ctrl_addr +
- WLED3_CTRL_REG_INT_RT_STS, &int_sts);
+ rc = wled_ovp_fault_status(wled, &fault_set);
if (rc < 0) {
- dev_err(wled->dev, "Error in reading WLED3_CTRL_INT_RT_STS rc=%d\n",
+ dev_err(wled->dev, "Error in getting OVP fault_sts, rc=%d\n",
rc);
goto failed_detect;
}

- if (int_sts & WLED3_CTRL_REG_OVP_FAULT_STATUS)
+ if (fault_set)
dev_dbg(wled->dev, "WLED OVP fault detected with SINK %d\n",
i + 1);
else
@@ -478,30 +556,30 @@ static void wled_auto_string_detection(struct wled *wled)
}

/* 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)
+ if (wled->version == 4) {
+ for (i = 0; i < wled->cfg.num_strings; i++) {
+ if (sink_config &
+ BIT(WLED4_SINK_REG_CURR_SINK_SHFT + i))
+ val = WLED4_SINK_REG_STR_MOD_MASK;
+ else
+ /* Disable modulator_en for unused sink */
+ val = 0;
+
+ 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;
- }
-
- 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;
+ }
}
}

+ /* Enable CABC */
+ rc = wled->wled_cabc_config(wled, true);
+ if (rc < 0)
+ goto failed_detect;
+
/* Restore the feedback setting */
rc = regmap_write(wled->regmap,
wled->ctrl_addr + WLED3_CTRL_REG_FEEDBACK_CONTROL, 0);
@@ -534,7 +612,8 @@ static void wled_auto_string_detection(struct wled *wled)

#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)
+
+static bool wled4_auto_detection_required(struct wled *wled)
{
s64 elapsed_time_us;

@@ -570,29 +649,19 @@ static bool wled_auto_detection_required(struct wled *wled)
static int wled_auto_detection_at_init(struct wled *wled)
{
int rc;
- u32 fault_status, rt_status;
+ bool fault_set;

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);
+ rc = wled_ovp_fault_status(wled, &fault_set);
if (rc < 0) {
- dev_err(wled->dev, "Failed to read fault status rc=%d\n", rc);
+ dev_err(wled->dev, "Error in getting OVP fault_sts, rc=%d\n",
+ rc);
return rc;
}

- if ((rt_status & WLED3_CTRL_REG_OVP_FAULT_STATUS) ||
- (fault_status & WLED3_CTRL_REG_OVP_FAULT_BIT)) {
+ if (fault_set) {
mutex_lock(&wled->lock);
wled_auto_string_detection(wled);
mutex_unlock(&wled->lock);
@@ -629,7 +698,7 @@ static irqreturn_t wled_ovp_irq_handler(int irq, void *_wled)
int_sts, fault_sts);

if (fault_sts & WLED3_CTRL_REG_OVP_FAULT_BIT) {
- if (wled_auto_detection_required(wled)) {
+ if (wled->wled_auto_detection_required(wled)) {
mutex_lock(&wled->lock);
wled_auto_string_detection(wled);
mutex_unlock(&wled->lock);
@@ -811,17 +880,12 @@ static int wled4_setup(struct wled *wled)
wled->cfg.string_i_limit);
if (rc < 0)
return rc;
-
- addr = wled->sink_addr +
- WLED4_SINK_REG_STR_CABC(j);
- rc = regmap_update_bits(wled->regmap, addr,
- WLED4_SINK_REG_STR_CABC_MASK,
- wled->cfg.cabc ?
- WLED4_SINK_REG_STR_CABC_MASK : 0);
- if (rc < 0)
- return rc;
}

+ rc = wled4_cabc_config(wled, wled->cfg.cabc);
+ if (rc < 0)
+ return rc;
+
rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
WLED3_CTRL_REG_MOD_EN,
WLED3_CTRL_REG_MOD_EN_MASK,
@@ -835,7 +899,7 @@ static int wled4_setup(struct wled *wled)
if (rc < 0)
return rc;

- rc = wled_sync_toggle(wled);
+ rc = wled->wled_sync_toggle(wled);
if (rc < 0) {
dev_err(wled->dev, "Failed to toggle sync reg rc:%d\n", rc);
return rc;
@@ -943,7 +1007,7 @@ static u32 wled_values(const struct wled_var_cfg *cfg, u32 idx)
return idx;
}

-static int wled_configure(struct wled *wled, int version)
+static int wled_configure(struct wled *wled)
{
struct wled_config *cfg = &wled->cfg;
struct device *dev = wled->dev;
@@ -1027,12 +1091,13 @@ static int wled_configure(struct wled *wled, int version)
if (rc)
wled->name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn", dev->of_node);

- switch (version) {
+ switch (wled->version) {
case 3:
u32_opts = wled3_opts;
size = ARRAY_SIZE(wled3_opts);
*cfg = wled3_config_defaults;
wled->wled_set_brightness = wled3_set_brightness;
+ wled->wled_sync_toggle = wled3_sync_toggle;
wled->max_string_count = 3;
wled->sink_addr = wled->ctrl_addr;
break;
@@ -1042,6 +1107,11 @@ static int wled_configure(struct wled *wled, int version)
size = ARRAY_SIZE(wled4_opts);
*cfg = wled4_config_defaults;
wled->wled_set_brightness = wled4_set_brightness;
+ wled->wled_sync_toggle = wled3_sync_toggle;
+ wled->wled_cabc_config = wled4_cabc_config;
+ wled->wled_ovp_delay = wled4_ovp_delay;
+ wled->wled_auto_detection_required =
+ wled4_auto_detection_required;
wled->max_string_count = 4;

prop_addr = of_get_address(dev->of_node, 1, NULL, NULL);
@@ -1178,7 +1248,6 @@ static int wled_probe(struct platform_device *pdev)
struct backlight_device *bl;
struct wled *wled;
struct regmap *regmap;
- int version;
u32 val;
int rc;

@@ -1195,18 +1264,18 @@ static int wled_probe(struct platform_device *pdev)
wled->regmap = regmap;
wled->dev = &pdev->dev;

- version = (uintptr_t)of_device_get_match_data(&pdev->dev);
- if (!version) {
+ wled->version = (uintptr_t)of_device_get_match_data(&pdev->dev);
+ if (!wled->version) {
dev_err(&pdev->dev, "Unknown device version\n");
return -ENODEV;
}

mutex_init(&wled->lock);
- rc = wled_configure(wled, version);
+ rc = wled_configure(wled);
if (rc)
return rc;

- switch (version) {
+ switch (wled->version) {
case 3:
wled->cfg.auto_detection_enabled = false;
rc = wled3_setup(wled);
--
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