Re: [PATCH V4 2/4] backlight: qcom-wled: Add callback functions

From: kgunda
Date: Mon Mar 30 2020 - 10:45:57 EST

Next message: Sebastian Andrzej Siewior: "[ANNOUNCE] v5.4.28-rt19"
Previous message: David Howells: "[GIT PULL] fsinfo: Filesystem information query"
In reply to: Daniel Thompson: "Re: [PATCH V4 2/4] backlight: qcom-wled: Add callback functions"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On 2020-03-25 21:00, Daniel Thompson wrote:

On Mon, Mar 23, 2020 at 11:16:56PM +0530, Kiran Gunda wrote:

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

wled_cabc_config() ===> Used to configure the cabc register.
It is applicable for wled4 and wled5.

wled_sync_toggle() ===> used to toggle the Sync register bit for the
brightness update to take place.
It is applicable for WLED3, WLED4 and WLED5.

wled_ovp_fault_status() ===> Used to determine if the OVP fault is triggered.
It is applicable for WLED4 and WLED5.

wled_ovp_delay() ===> Provides the time to wait before checking the OVP status
after wled module enable.
It is applicable for WLED4 and WLED5.

These look like comments to me. Move them out of the patch header and
make them into real comments!

Sure. Will do it in next post.

Signed-off-by: Kiran Gunda <kgunda@xxxxxxxxxxxxxx>

This patch does not compile. Please fix this.

Sorry for that. Some how it didn't show up in my compilation.
Will fix it in next post.

---
drivers/video/backlight/qcom-wled.c | 188 ++++++++++++++++++++++--------------
1 file changed, 118 insertions(+), 70 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index 3d276b3..a3daf9e 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;

Why does some of the changes here use function pointers and other parts
use if/else networks (wled->version == X) ?

There is one place (in auto_string_detection) where we have to add the
if (version == 4) because the per string modulator_enable is present only
for WLED4 and there is no equivalent functionality available for WLED5.

There is another place, that i can convert it to the function pointer (auto_detection_required).

Overall I almost wonder if the reduced clarify that comes from function
pointers is actually adding much value?

I believe adding the function pointer makes it cleaner and the same approach is used for
WLED4/WLED3 also.

bool disabled_by_short;
bool has_short_detect;
int short_irq;
@@ -155,6 +156,10 @@ struct wled {
struct wled_config cfg;
struct delayed_work ovp_work;
int (*wled_set_brightness)(struct wled *wled, u16 brightness);
+ int (*wled_cabc_config)(struct wled *wled, bool enable);
+ int (*wled_sync_toggle)(struct wled *wled);
+ int (*wled_ovp_fault_status)(struct wled *wled, bool *fault_set);
+ int (*wled_ovp_delay)(struct wled *wled);
};

static int wled3_set_brightness(struct wled *wled, u16 brightness)
@@ -237,7 +242,7 @@ 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 +260,46 @@ static int wled_sync_toggle(struct wled *wled)
return rc;
}

+static int wled4_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 +320,7 @@ 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 +343,25 @@ 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 +409,10 @@ 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 +441,9 @@ 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, 0);

Be consistent with the argument (elsewhere it is true/false).

Will address in the next post.

+ if (rc < 0)
+ goto failed_detect;
}

/* Disable all sinks */
@@ -427,18 +487,17 @@ 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->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 +537,30 @@ 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 = 0x0;
+
+ 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 if it needs to be enabled */

If it needs to be enabled?

Ok. Actually Enable CABC should be enough. I will remove the latter part
in the next post.

+ 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);
@@ -570,29 +629,19 @@ 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);
+ rc = wled->wled_ovp_fault_status(wled, &fault_set);
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);
+ 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);
@@ -811,17 +860,12 @@ 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.en_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 +879,7 @@ 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;
@@ -951,7 +995,7 @@ 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;
@@ -1035,12 +1079,13 @@ 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;
@@ -1050,6 +1095,10 @@ 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_fault_status = wled4_ovp_fault_status;
+ wled->wled_ovp_delay = wled4_ovp_delay;
wled->max_string_count = 4;

prop_addr = of_get_address(dev->of_node, 1, NULL, NULL);
@@ -1186,7 +1235,6 @@ static int wled_probe(struct platform_device *pdev)
struct backlight_device *bl;
struct wled *wled;
struct regmap *regmap;
- int version;
u32 val;
int rc;

@@ -1203,18 +1251,18 @@ 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);
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Next message: Sebastian Andrzej Siewior: "[ANNOUNCE] v5.4.28-rt19"
Previous message: David Howells: "[GIT PULL] fsinfo: Filesystem information query"
In reply to: Daniel Thompson: "Re: [PATCH V4 2/4] backlight: qcom-wled: Add callback functions"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]