[PATCH 1/2] mfd: pca9450: configure pmic reset behavior

[Jonas Rebmann]

Currently, boards using the pca9450 pmic driver initialize the
RESET_CTRL register either in lowlevel.c or board.c explicitly to 0xA1
to enable the watchdog for Cold Reset with all voltage regulators
recycled except LDO1/ LDO2 in addition to the default configuration of
0x11 where the WDOG_B watchdog input is disabled.

Instead, enable the watchdog in the driver for Cold Reset with all
voltage regulators recycled except LDO1/ LDO2. When
nxp,wdog_b-warm-reset is set, the watchdog is instead enabled for Warm
Reset.

This is identical to U-Boot's behaviour since commit 910c7a881f5 and
Linux's since commit 2364a64d0673f.

Signed-off-by: Jonas Rebmann <jre at pengutronix.de>
---
 drivers/mfd/pca9450.c | 11 +++++++++++
 include/mfd/pca9450.h |  4 ++++
 2 files changed, 15 insertions(+)

diff --git a/drivers/mfd/pca9450.c b/drivers/mfd/pca9450.c
index 2511e662c3dfb5dfedbc461357ffa82d1812166f..6d6fb32c36569689b901455b3376c92977eabc37 100644
--- a/drivers/mfd/pca9450.c
+++ b/drivers/mfd/pca9450.c
@@ -3,6 +3,7 @@
  * Copyright (C) 2023 Holger Assmann, Pengutronix
  */
 
+#include "linux/regmap.h"
 #include <common.h>
 #include <driver.h>
 #include <errno.h>
@@ -103,6 +104,16 @@ static int __init pca9450_probe(struct device *dev)
 	/* Chip ID defined in bits [7:4] */
 	dev_info(dev, "PMIC Chip ID: 0x%x\n", (reg >> 4));
 
+	/* Enable WDOG_B, for cold reset by default */
+	if (of_property_read_bool(dev->of_node, "nxp,wdog_b-warm-reset"))
+		regmap_update_bits(regmap, PCA9450_RESET_CTRL,
+				   PCA9450_PMIC_RESET_WDOG_B_CFG_MASK,
+				   PCA9450_PMIC_RESET_WDOG_B_CFG_WARM);
+	else
+		regmap_update_bits(regmap, PCA9450_RESET_CTRL,
+				   PCA9450_PMIC_RESET_WDOG_B_CFG_MASK,
+				   PCA9450_PMIC_RESET_WDOG_B_CFG_COLD_LDO12);
+
 	if (pca9450_init_callback)
 		pca9450_init_callback(regmap);
 	pca9450_map = regmap;
diff --git a/include/mfd/pca9450.h b/include/mfd/pca9450.h
index 7071c3a9da6c5adc26dbd6149fec5fa96f3365bf..af10e409855ff6c3585c7f63098a16e8ec33dee2 100644
--- a/include/mfd/pca9450.h
+++ b/include/mfd/pca9450.h
@@ -66,4 +66,8 @@ static inline int pca9450_register_init_callback(void(*callback)(struct regmap *
 }
 #endif
 
+#define PCA9450_PMIC_RESET_WDOG_B_CFG_MASK		0xc0
+#define PCA9450_PMIC_RESET_WDOG_B_CFG_WARM		0x40
+#define PCA9450_PMIC_RESET_WDOG_B_CFG_COLD_LDO12	0x80
+
 #endif

-- 
2.39.5