mfd: twl-core: Add power off implementation for twl603x

If the system-power-controller property is there, enable power off.
Implementation is based on a Linux v3.0 vendor kernel.
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Link: https://lore.kernel.org/r/20240217082007.3238948-3-andreas@kemnade.infoSigned-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/twl-core.c

@@ -124,6 +124,11 @@
 #define TWL6030_BASEADD_RSV		0x0000
 #define TWL6030_BASEADD_ZERO		0x0000
 
+/* Some fields in TWL6030_PHOENIX_DEV_ON */
+#define TWL6030_APP_DEVOFF		BIT(0)
+#define TWL6030_CON_DEVOFF		BIT(1)
+#define TWL6030_MOD_DEVOFF		BIT(2)
+
 /* Few power values */
 #define R_CFG_BOOT			0x05
 
@@ -687,6 +692,20 @@ static void twl_remove(struct i2c_client *client)
 	twl_priv->ready = false;
 }
 
+static void twl6030_power_off(void)
+{
+	int err;
+	u8 val;
+
+	err = twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &val, TWL6030_PHOENIX_DEV_ON);
+	if (err)
+		return;
+
+	val |= TWL6030_APP_DEVOFF | TWL6030_CON_DEVOFF | TWL6030_MOD_DEVOFF;
+	twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val, TWL6030_PHOENIX_DEV_ON);
+}
+
+
 static struct of_dev_auxdata twl_auxdata_lookup[] = {
 	OF_DEV_AUXDATA("ti,twl4030-gpio", 0, "twl4030-gpio", NULL),
 	{ /* sentinel */ },
@@ -852,6 +871,15 @@ twl_probe(struct i2c_client *client)
 			goto free;
 	}
 
+	if (twl_class_is_6030()) {
+		if (of_device_is_system_power_controller(node)) {
+			if (!pm_power_off)
+				pm_power_off = twl6030_power_off;
+			else
+				dev_warn(&client->dev, "Poweroff callback already assigned\n");
+		}
+	}
+
 	status = of_platform_populate(node, NULL, twl_auxdata_lookup,
 				      &client->dev);
 

include/linux/mfd/twl.h

@@ -461,6 +461,7 @@ static inline int twl6030_mmc_card_detect(struct device *dev, int slot)
 
 #define TWL4030_PM_MASTER_GLOBAL_TST		0xb6
 
+#define TWL6030_PHOENIX_DEV_ON                  0x06
 /*----------------------------------------------------------------------*/
 
 /* Power bus message definitions */