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[PATCH 3/4] backlight: ktz8866: improve current sinks setting

Pengyu Luo posted 4 patches 10 months, 1 week ago
[PATCH 3/4] backlight: ktz8866: improve current sinks setting
Posted by Pengyu Luo 10 months, 1 week ago 
I polled all registers when the module was loading, found that
current sinks have already been configured. Bootloader would set
when booting. So checking it before setting the all channels.

Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
---
 drivers/video/backlight/ktz8866.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/video/backlight/ktz8866.c b/drivers/video/backlight/ktz8866.c
index 017ad80dd..b67ca136d 100644
--- a/drivers/video/backlight/ktz8866.c
+++ b/drivers/video/backlight/ktz8866.c
@@ -46,6 +46,8 @@
 #define LCD_BIAS_EN 0x9F
 #define PWM_HYST 0x5
 
+#define CURRENT_SINKS_MASK GENMASK(5, 0)
+
 struct ktz8866_slave {
 	struct i2c_client *client;
 	struct regmap *regmap;
@@ -65,6 +67,12 @@ static const struct regmap_config ktz8866_regmap_config = {
 	.max_register = REG_MAX,
 };
 
+static inline void ktz8866_read(struct ktz8866 *ktz, unsigned int reg,
+				unsigned int *val)
+{
+	regmap_read(ktz->regmap, reg, &val);
+}
+
 static void ktz8866_write(struct ktz8866 *ktz, unsigned int reg,
 			  unsigned int val)
 {
@@ -112,11 +120,18 @@ static void ktz8866_init(struct ktz8866 *ktz)
 {
 	unsigned int val = 0;
 
-	if (!of_property_read_u32(ktz->client->dev.of_node, "current-num-sinks", &val))
+	if (!of_property_read_u32(ktz->client->dev.of_node, "current-num-sinks", &val)) {
 		ktz8866_write(ktz, BL_EN, BIT(val) - 1);
-	else
-		/* Enable all 6 current sinks if the number of current sinks isn't specified. */
-		ktz8866_write(ktz, BL_EN, BIT(6) - 1);
+	} else {
+		/*
+		 * Enable all 6 current sinks if the number of current
+		 * sinks isn't specified and the bootloader didn't set
+		 * the value.
+		 */
+		ktz8866_read(ktz, BL_EN, &val);
+		if (!(val && CURRENT_SINKS_MASK))
+			ktz8866_write(ktz, BL_EN, CURRENT_SINKS_MASK);
+	}
 
 	if (!of_property_read_u32(ktz->client->dev.of_node, "kinetic,current-ramp-delay-ms", &val)) {
 		if (val <= 128)
-- 
2.49.0
Re: [PATCH 3/4] backlight: ktz8866: improve current sinks setting
Posted by kernel test robot 10 months ago 
Hi Pengyu,

kernel test robot noticed the following build errors:

[auto build test ERROR on lee-backlight/for-backlight-next]
[also build test ERROR on lee-leds/for-leds-next lee-backlight/for-backlight-fixes linus/master v6.15-rc1 next-20250407]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Pengyu-Luo/dt-bindings-backlight-kinetic-ktz8866-add-ktz8866-slave-compatible/20250407-175635
base:   https://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight.git for-backlight-next
patch link:    https://lore.kernel.org/r/20250407095119.588920-4-mitltlatltl%40gmail.com
patch subject: [PATCH 3/4] backlight: ktz8866: improve current sinks setting
config: sparc64-randconfig-002-20250408 (https://download.01.org/0day-ci/archive/20250408/202504081106.mAYfJsQj-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250408/202504081106.mAYfJsQj-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202504081106.mAYfJsQj-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/video/backlight/ktz8866.c: In function 'ktz8866_read':
>> drivers/video/backlight/ktz8866.c:73:39: error: passing argument 3 of 'regmap_read' from incompatible pointer type [-Wincompatible-pointer-types]
      73 |         regmap_read(ktz->regmap, reg, &val);
         |                                       ^~~~
         |                                       |
         |                                       unsigned int **
   In file included from drivers/video/backlight/ktz8866.c:17:
   include/linux/regmap.h:1297:69: note: expected 'unsigned int *' but argument is of type 'unsigned int **'
    1297 | int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
         |                                                       ~~~~~~~~~~~~~~^~~


vim +/regmap_read +73 drivers/video/backlight/ktz8866.c

    69	
    70	static inline void ktz8866_read(struct ktz8866 *ktz, unsigned int reg,
    71					unsigned int *val)
    72	{
  > 73		regmap_read(ktz->regmap, reg, &val);
    74	}
    75	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH 3/4] backlight: ktz8866: improve current sinks setting
Posted by kernel test robot 10 months ago 
Hi Pengyu,

kernel test robot noticed the following build errors:

[auto build test ERROR on lee-backlight/for-backlight-next]
[also build test ERROR on lee-leds/for-leds-next lee-backlight/for-backlight-fixes linus/master v6.15-rc1 next-20250407]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Pengyu-Luo/dt-bindings-backlight-kinetic-ktz8866-add-ktz8866-slave-compatible/20250407-175635
base:   https://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight.git for-backlight-next
patch link:    https://lore.kernel.org/r/20250407095119.588920-4-mitltlatltl%40gmail.com
patch subject: [PATCH 3/4] backlight: ktz8866: improve current sinks setting
config: riscv-randconfig-002-20250408 (https://download.01.org/0day-ci/archive/20250408/202504081109.E7PjHxpa-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project 92c93f5286b9ff33f27ff694d2dc33da1c07afdd)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250408/202504081109.E7PjHxpa-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202504081109.E7PjHxpa-lkp@intel.com/

All error/warnings (new ones prefixed by >>):

>> drivers/video/backlight/ktz8866.c:73:32: error: incompatible pointer types passing 'unsigned int **' to parameter of type 'unsigned int *'; remove & [-Werror,-Wincompatible-pointer-types]
      73 |         regmap_read(ktz->regmap, reg, &val);
         |                                       ^~~~
   include/linux/regmap.h:1297:69: note: passing argument to parameter 'val' here
    1297 | int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
         |                                                                     ^
>> drivers/video/backlight/ktz8866.c:132:13: warning: use of logical '&&' with constant operand [-Wconstant-logical-operand]
     132 |                 if (!(val && CURRENT_SINKS_MASK))
         |                           ^  ~~~~~~~~~~~~~~~~~~
   drivers/video/backlight/ktz8866.c:132:13: note: use '&' for a bitwise operation
     132 |                 if (!(val && CURRENT_SINKS_MASK))
         |                           ^~
         |                           &
   drivers/video/backlight/ktz8866.c:132:13: note: remove constant to silence this warning
     132 |                 if (!(val && CURRENT_SINKS_MASK))
         |                           ^~~~~~~~~~~~~~~~~~~~~
   1 warning and 1 error generated.


vim +73 drivers/video/backlight/ktz8866.c

    69	
    70	static inline void ktz8866_read(struct ktz8866 *ktz, unsigned int reg,
    71					unsigned int *val)
    72	{
  > 73		regmap_read(ktz->regmap, reg, &val);
    74	}
    75	
    76	static void ktz8866_write(struct ktz8866 *ktz, unsigned int reg,
    77				  unsigned int val)
    78	{
    79		regmap_write(ktz->regmap, reg, val);
    80	
    81		if (ktz->slave)
    82			regmap_write(ktz->slave->regmap, reg, val);
    83	}
    84	
    85	static void ktz8866_update_bits(struct ktz8866 *ktz, unsigned int reg,
    86					unsigned int mask, unsigned int val)
    87	{
    88		regmap_update_bits(ktz->regmap, reg, mask, val);
    89	
    90		if (ktz->slave)
    91			regmap_update_bits(ktz->slave->regmap, reg, mask, val);
    92	}
    93	
    94	static int ktz8866_backlight_update_status(struct backlight_device *backlight_dev)
    95	{
    96		struct ktz8866 *ktz = bl_get_data(backlight_dev);
    97		unsigned int brightness = backlight_get_brightness(backlight_dev);
    98	
    99		if (!ktz->led_on && brightness > 0) {
   100			ktz8866_update_bits(ktz, BL_EN, BL_EN_BIT, BL_EN_BIT);
   101			ktz->led_on = true;
   102		} else if (brightness == 0) {
   103			ktz8866_update_bits(ktz, BL_EN, BL_EN_BIT, 0);
   104			ktz->led_on = false;
   105		}
   106	
   107		/* Set brightness */
   108		ktz8866_write(ktz, BL_BRT_LSB, brightness & 0x7);
   109		ktz8866_write(ktz, BL_BRT_MSB, (brightness >> 3) & 0xFF);
   110	
   111		return 0;
   112	}
   113	
   114	static const struct backlight_ops ktz8866_backlight_ops = {
   115		.options = BL_CORE_SUSPENDRESUME,
   116		.update_status = ktz8866_backlight_update_status,
   117	};
   118	
   119	static void ktz8866_init(struct ktz8866 *ktz)
   120	{
   121		unsigned int val = 0;
   122	
   123		if (!of_property_read_u32(ktz->client->dev.of_node, "current-num-sinks", &val)) {
   124			ktz8866_write(ktz, BL_EN, BIT(val) - 1);
   125		} else {
   126			/*
   127			 * Enable all 6 current sinks if the number of current
   128			 * sinks isn't specified and the bootloader didn't set
   129			 * the value.
   130			 */
   131			ktz8866_read(ktz, BL_EN, &val);
 > 132			if (!(val && CURRENT_SINKS_MASK))
   133				ktz8866_write(ktz, BL_EN, CURRENT_SINKS_MASK);
   134		}
   135	
   136		if (!of_property_read_u32(ktz->client->dev.of_node, "kinetic,current-ramp-delay-ms", &val)) {
   137			if (val <= 128)
   138				ktz8866_write(ktz, BL_CFG2, BIT(7) | (ilog2(val) << 3) | PWM_HYST);
   139			else
   140				ktz8866_write(ktz, BL_CFG2, BIT(7) | ((5 + val / 64) << 3) | PWM_HYST);
   141		}
   142	
   143		if (!of_property_read_u32(ktz->client->dev.of_node, "kinetic,led-enable-ramp-delay-ms", &val)) {
   144			if (val == 0)
   145				ktz8866_write(ktz, BL_DIMMING, 0);
   146			else {
   147				unsigned int ramp_off_time = ilog2(val) + 1;
   148				unsigned int ramp_on_time = ramp_off_time << 4;
   149				ktz8866_write(ktz, BL_DIMMING, ramp_on_time | ramp_off_time);
   150			}
   151		}
   152	
   153		if (of_property_read_bool(ktz->client->dev.of_node, "kinetic,enable-lcd-bias"))
   154			ktz8866_write(ktz, LCD_BIAS_CFG1, LCD_BIAS_EN);
   155	}
   156	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH 3/4] backlight: ktz8866: improve current sinks setting
Posted by Daniel Thompson 10 months ago 
On Mon, Apr 07, 2025 at 05:51:18PM +0800, Pengyu Luo wrote:
> I polled all registers when the module was loading, found that
> current sinks have already been configured. Bootloader would set
> when booting. So checking it before setting the all channels.

Can you rephrase this so the problem and solution are more clearly
expressed. Perhaps template Ingo suggests here would be good:
https://www.spinics.net/lists/kernel/msg1633438.html


> Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> ---
>  drivers/video/backlight/ktz8866.c | 23 +++++++++++++++++++----
>  1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/video/backlight/ktz8866.c b/drivers/video/backlight/ktz8866.c
> index 017ad80dd..b67ca136d 100644
> --- a/drivers/video/backlight/ktz8866.c
> +++ b/drivers/video/backlight/ktz8866.c
> @@ -46,6 +46,8 @@
>  #define LCD_BIAS_EN 0x9F
>  #define PWM_HYST 0x5
>
> +#define CURRENT_SINKS_MASK GENMASK(5, 0)
> +

Call this BL_EN_CURRENT_SINKS_MASK and keep it next to the register it
applies to.


>  struct ktz8866_slave {
>  	struct i2c_client *client;
>  	struct regmap *regmap;
> @@ -112,11 +120,18 @@ static void ktz8866_init(struct ktz8866 *ktz)
>  {
>  	unsigned int val = 0;
>
> -	if (!of_property_read_u32(ktz->client->dev.of_node, "current-num-sinks", &val))
> +	if (!of_property_read_u32(ktz->client->dev.of_node, "current-num-sinks", &val)) {
>  		ktz8866_write(ktz, BL_EN, BIT(val) - 1);
> -	else
> -		/* Enable all 6 current sinks if the number of current sinks isn't specified. */
> -		ktz8866_write(ktz, BL_EN, BIT(6) - 1);
> +	} else {
> +		/*
> +		 * Enable all 6 current sinks if the number of current
> +		 * sinks isn't specified and the bootloader didn't set
> +		 * the value.
> +		 */
> +		ktz8866_read(ktz, BL_EN, &val);
> +		if (!(val && CURRENT_SINKS_MASK))

This is the wrong form of AND.

> +			ktz8866_write(ktz, BL_EN, CURRENT_SINKS_MASK);
> +	}


Daniel.

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