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>

1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/leds/leds-lp55xx-common.c b/drivers/leds/leds-lp55xx-common.c
index 8e7074f0fee0..2cbc5b302fd4 100644
--- a/drivers/leds/leds-lp55xx-common.c
+++ b/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;