leds: leds-lp55xx: Generalize stop_all_engine OP

In all the lp55xx based driver, we have a similar implementation of the
stop_all_engine function with the only difference of the required sleep
for the OP MODE change.

The main difference is legacy LEDs require a min of 152 us while new one
use a generic 1-2ms. The new one use a 1-2ms sleep as suggested in the
datasheet IN ALTERNATIVE to a much more robust approach by using the
newly introduced ENGINE_BUSY bit in the STATUS reg.

To better handle sleep after OP MODE change, add support for polling the
ENGINE_BUSY bit and use the legacy sleep for old LEDs.

With this change, stop_all_engine can be generalized and moved to
lp55xx-common.

To make more clear the double usage of lp55xx_reg, define a union for
additional scope of mask and shift.

Update all lp55xx based driver to use the new generalized function and
define the required bits in the device_config struct.

Suggested-by: Lee Jones <lee@kernel.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20240626160027.19703-4-ansuelsmth@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

Author: Ansuel

drivers/leds/leds-lp5521.c

@@ -135,12 +135,6 @@ static void lp5521_load_engine(struct lp55xx_chip *chip)
 	lp5521_wait_opmode_done();
 }
 
-static void lp5521_stop_all_engines(struct lp55xx_chip *chip)
-{
-	lp55xx_write(chip, LP5521_REG_OP_MODE, 0);
-	lp5521_wait_opmode_done();
-}
-
 static void lp5521_stop_engine(struct lp55xx_chip *chip)
 {
 	enum lp55xx_engine_index idx = chip->engine_idx;
@@ -499,6 +493,9 @@ static const struct attribute_group lp5521_group = {
 
 /* Chip specific configurations */
 static struct lp55xx_device_config lp5521_cfg = {
+	.reg_op_mode = {
+		.addr = LP5521_REG_OP_MODE,
+	},
 	.reset = {
 		.addr = LP5521_REG_RESET,
 		.val  = LP5521_RESET,
@@ -585,7 +582,7 @@ static void lp5521_remove(struct i2c_client *client)
 	struct lp55xx_led *led = i2c_get_clientdata(client);
 	struct lp55xx_chip *chip = led->chip;
 
-	lp5521_stop_all_engines(chip);
+	lp55xx_stop_all_engine(chip);
 	lp55xx_unregister_sysfs(chip);
 	lp55xx_deinit_device(chip);
 }

drivers/leds/leds-lp5523.c

@@ -41,7 +41,10 @@
 #define LP5523_REG_LED_PWM_BASE		0x16
 #define LP5523_REG_LED_CURRENT_BASE	0x26
 #define LP5523_REG_CONFIG		0x36
+
 #define LP5523_REG_STATUS		0x3A
+#define LP5523_ENGINE_BUSY		BIT(4)
+
 #define LP5523_REG_RESET		0x3D
 #define LP5523_REG_LED_TEST_CTRL	0x41
 #define LP5523_REG_LED_TEST_ADC		0x42
@@ -190,12 +193,6 @@ static void lp5523_load_engine_and_select_page(struct lp55xx_chip *chip)
 	lp55xx_write(chip, LP5523_REG_PROG_PAGE_SEL, page_sel[idx]);
 }
 
-static void lp5523_stop_all_engines(struct lp55xx_chip *chip)
-{
-	lp55xx_write(chip, LP5523_REG_OP_MODE, 0);
-	lp5523_wait_opmode_done();
-}
-
 static void lp5523_stop_engine(struct lp55xx_chip *chip)
 {
 	enum lp55xx_engine_index idx = chip->engine_idx;
@@ -322,7 +319,7 @@ static int lp5523_init_program_engine(struct lp55xx_chip *chip)
 	}
 
 out:
-	lp5523_stop_all_engines(chip);
+	lp55xx_stop_all_engine(chip);
 	return ret;
 }
 
@@ -873,6 +870,13 @@ static const struct attribute_group lp5523_group = {
 
 /* Chip specific configurations */
 static struct lp55xx_device_config lp5523_cfg = {
+	.reg_op_mode = {
+		.addr = LP5523_REG_OP_MODE,
+	},
+	.engine_busy = {
+		.addr = LP5523_REG_STATUS,
+		.mask  = LP5523_ENGINE_BUSY,
+	},
 	.reset = {
 		.addr = LP5523_REG_RESET,
 		.val  = LP5523_RESET,
@@ -959,7 +963,7 @@ static void lp5523_remove(struct i2c_client *client)
 	struct lp55xx_led *led = i2c_get_clientdata(client);
 	struct lp55xx_chip *chip = led->chip;
 
-	lp5523_stop_all_engines(chip);
+	lp55xx_stop_all_engine(chip);
 	lp55xx_unregister_sysfs(chip);
 	lp55xx_deinit_device(chip);
 }

drivers/leds/leds-lp5562.c

@@ -144,12 +144,6 @@ static void lp5562_load_engine(struct lp55xx_chip *chip)
 	lp5562_wait_opmode_done();
 }
 
-static void lp5562_stop_engine(struct lp55xx_chip *chip)
-{
-	lp55xx_write(chip, LP5562_REG_OP_MODE, LP5562_CMD_DISABLE);
-	lp5562_wait_opmode_done();
-}
-
 static void lp5562_run_engine(struct lp55xx_chip *chip, bool start)
 {
 	int ret;
@@ -160,7 +154,7 @@ static void lp5562_run_engine(struct lp55xx_chip *chip, bool start)
 	if (!start) {
 		lp55xx_write(chip, LP5562_REG_ENABLE, LP5562_ENABLE_DEFAULT);
 		lp5562_wait_enable_done();
-		lp5562_stop_engine(chip);
+		lp55xx_stop_all_engine(chip);
 		lp55xx_write(chip, LP5562_REG_ENG_SEL, LP5562_ENG_SEL_PWM);
 		lp55xx_write(chip, LP5562_REG_OP_MODE, LP5562_CMD_DIRECT);
 		lp5562_wait_opmode_done();
@@ -369,7 +363,7 @@ static int lp5562_run_predef_led_pattern(struct lp55xx_chip *chip, int mode)
 		return -EINVAL;
 	}
 
-	lp5562_stop_engine(chip);
+	lp55xx_stop_all_engine(chip);
 
 	/* Set LED map as RGB */
 	lp55xx_write(chip, LP5562_REG_ENG_SEL, LP5562_ENG_SEL_RGB);
@@ -495,6 +489,9 @@ static const struct attribute_group lp5562_group = {
 /* Chip specific configurations */
 static struct lp55xx_device_config lp5562_cfg = {
 	.max_channel  = LP5562_MAX_LEDS,
+	.reg_op_mode = {
+		.addr = LP5562_REG_OP_MODE,
+	},
 	.reset = {
 		.addr = LP5562_REG_RESET,
 		.val  = LP5562_RESET,
@@ -577,7 +574,7 @@ static void lp5562_remove(struct i2c_client *client)
 	struct lp55xx_led *led = i2c_get_clientdata(client);
 	struct lp55xx_chip *chip = led->chip;
 
-	lp5562_stop_engine(chip);
+	lp55xx_stop_all_engine(chip);
 
 	lp55xx_unregister_sysfs(chip);
 	lp55xx_deinit_device(chip);

drivers/leds/leds-lp55xx-common.c

@@ -13,6 +13,7 @@
 #include <linux/delay.h>
 #include <linux/firmware.h>
 #include <linux/i2c.h>
+#include <linux/iopoll.h>
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/platform_data/leds-lp55xx.h>
@@ -22,6 +23,12 @@
 
 #include "leds-lp55xx-common.h"
 
+/* OP MODE require at least 153 us to clear regs */
+#define LP55XX_CMD_SLEEP		200
+
+/* Program Commands */
+#define LP55xx_MODE_DISABLE_ALL_ENG	0x0
+
 /* External clock rate */
 #define LP55XX_CLK_32K			32768
 
@@ -40,6 +47,35 @@ static struct lp55xx_led *mcled_cdev_to_led(struct led_classdev_mc *mc_cdev)
 	return container_of(mc_cdev, struct lp55xx_led, mc_cdev);
 }
 
+static void lp55xx_wait_opmode_done(struct lp55xx_chip *chip)
+{
+	struct lp55xx_device_config *cfg = chip->cfg;
+	int __always_unused ret;
+	u8 val;
+
+	/*
+	 * Recent chip supports BUSY bit for engine.
+	 * Check support by checking if val is not 0.
+	 * For legacy device, sleep at least 153 us.
+	 */
+	if (cfg->engine_busy.val) {
+		read_poll_timeout(lp55xx_read, ret, !(val & cfg->engine_busy.mask),
+				  LP55XX_CMD_SLEEP, LP55XX_CMD_SLEEP * 10, false,
+				  chip, cfg->engine_busy.addr, &val);
+	} else {
+		usleep_range(LP55XX_CMD_SLEEP, LP55XX_CMD_SLEEP * 2);
+	}
+}
+
+void lp55xx_stop_all_engine(struct lp55xx_chip *chip)
+{
+	struct lp55xx_device_config *cfg = chip->cfg;
+
+	lp55xx_write(chip, cfg->reg_op_mode.addr, LP55xx_MODE_DISABLE_ALL_ENG);
+	lp55xx_wait_opmode_done(chip);
+}
+EXPORT_SYMBOL_GPL(lp55xx_stop_all_engine);
+
 static void lp55xx_reset_device(struct lp55xx_chip *chip)
 {
 	struct lp55xx_device_config *cfg = chip->cfg;

drivers/leds/leds-lp55xx-common.h

@@ -81,15 +81,22 @@ struct lp55xx_chip;
 /*
  * struct lp55xx_reg
  * @addr : Register address
- * @val  : Register value
+ * @val  : Register value (can also used as mask or shift)
  */
 struct lp55xx_reg {
 	u8 addr;
-	u8 val;
+	union {
+		u8 val;
+		u8 mask;
+		u8 shift;
+	};
 };
 
 /*
  * struct lp55xx_device_config
+ * @reg_op_mode        : Chip specific OP MODE reg addr
+ * @engine_busy        : Chip specific engine busy
+ *			 (if not supported 153 us sleep)
  * @reset              : Chip specific reset command
  * @enable             : Chip specific enable command
  * @max_channel        : Maximum number of channels
@@ -102,6 +109,8 @@ struct lp55xx_reg {
  * @dev_attr_group     : Device specific attributes
  */
 struct lp55xx_device_config {
+	const struct lp55xx_reg reg_op_mode; /* addr, shift */
+	const struct lp55xx_reg engine_busy; /* addr, mask */
 	const struct lp55xx_reg reset;
 	const struct lp55xx_reg enable;
 	const int max_channel;
@@ -191,6 +200,9 @@ extern int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg,
 /* external clock detection */
 extern bool lp55xx_is_extclk_used(struct lp55xx_chip *chip);
 
+/* common chip functions */
+extern void lp55xx_stop_all_engine(struct lp55xx_chip *chip);
+
 /* common device init/deinit functions */
 extern int lp55xx_init_device(struct lp55xx_chip *chip);
 extern void lp55xx_deinit_device(struct lp55xx_chip *chip);

drivers/leds/leds-lp8501.c

@@ -58,6 +58,9 @@
 #define LP8501_INT_CLK			BIT(0)
 #define LP8501_DEFAULT_CFG (LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE)
 
+#define LP8501_REG_STATUS		0x3A
+#define LP8501_ENGINE_BUSY		BIT(4)
+
 #define LP8501_REG_RESET		0x3D
 #define LP8501_RESET			0xFF
 
@@ -141,12 +144,6 @@ static void lp8501_load_engine(struct lp55xx_chip *chip)
 	lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, page_sel[idx]);
 }
 
-static void lp8501_stop_engine(struct lp55xx_chip *chip)
-{
-	lp55xx_write(chip, LP8501_REG_OP_MODE, 0);
-	lp8501_wait_opmode_done();
-}
-
 static void lp8501_turn_off_channels(struct lp55xx_chip *chip)
 {
 	int i;
@@ -163,7 +160,7 @@ static void lp8501_run_engine(struct lp55xx_chip *chip, bool start)
 
 	/* stop engine */
 	if (!start) {
-		lp8501_stop_engine(chip);
+		lp55xx_stop_all_engine(chip);
 		lp8501_turn_off_channels(chip);
 		return;
 	}
@@ -285,6 +282,13 @@ static int lp8501_led_brightness(struct lp55xx_led *led)
 
 /* Chip specific configurations */
 static struct lp55xx_device_config lp8501_cfg = {
+	.reg_op_mode = {
+		.addr = LP8501_REG_OP_MODE,
+	},
+	.engine_busy = {
+		.addr = LP8501_REG_STATUS,
+		.maks = LP8501_ENGINE_BUSY,
+	},
 	.reset = {
 		.addr = LP8501_REG_RESET,
 		.val  = LP8501_RESET,
@@ -369,7 +373,7 @@ static void lp8501_remove(struct i2c_client *client)
 	struct lp55xx_led *led = i2c_get_clientdata(client);
 	struct lp55xx_chip *chip = led->chip;
 
-	lp8501_stop_engine(chip);
+	lp55xx_stop_all_engine(chip);
 	lp55xx_unregister_sysfs(chip);
 	lp55xx_deinit_device(chip);
 }