[PATCH] Input: axp20x-pek - add support for AXP313A variant

[steven]

Add power button support for the AXP313A PMIC. The AXP313A does not
have the PEK_KEY register (0x36) used to configure startup and shutdown
timings, unlike AXP20X and AXP221. Create a dedicated axp313a_info
configuration with NULL time tables to prevent regmap out-of-bounds
access.

The sysfs attributes (startup/shutdown) will return -EOPNOTSUPP when
accessed on AXP313A devices.

Signed-off-by: steven <steven@xxxxxxxxxxxxxxx>
---
Changes in v2:
- Fixed regmap out-of-bounds access issue reported by Sashiko AI
- Created dedicated axp313a_info with NULL time tables
- Added NULL pointer checks to prevent crashes
- AXP313A lacks PEK_KEY (0x36) per datasheet verification
- Power button still functional using hardware default timings

v1: https://lore.kernel.org/all/tencent_5F1FF80489E702360F352F889570656BF608@xxxxxx/
---
 drivers/input/misc/axp20x-pek.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/input/misc/axp20x-pek.c b/drivers/input/misc/axp20x-pek.c
index d4e2fc9a937f..de43eef0c0ea 100644
--- a/drivers/input/misc/axp20x-pek.c
+++ b/drivers/input/misc/axp20x-pek.c
@@ -85,6 +85,13 @@ static const struct axp20x_info axp221_info = {
 	.shutdown_mask = AXP20X_PEK_SHUTDOWN_MASK,
 };
 
+static const struct axp20x_info axp313a_info = {
+	.startup_time = NULL,
+	.startup_mask = 0,
+	.shutdown_time = NULL,
+	.shutdown_mask = 0,
+};
+
 static ssize_t axp20x_show_attr(struct device *dev,
 				const struct axp20x_time *time,
 				unsigned int mask, char *buf)
@@ -93,6 +100,9 @@ static ssize_t axp20x_show_attr(struct device *dev,
 	unsigned int val;
 	int ret, i;
 
+	if (!time)
+		return -EOPNOTSUPP;
+
 	ret = regmap_read(axp20x_pek->axp20x->regmap, AXP20X_PEK_KEY, &val);
 	if (ret != 0)
 		return ret;
@@ -137,6 +147,9 @@ static ssize_t axp20x_store_attr(struct device *dev,
 	unsigned int val, idx = 0;
 	unsigned int best_err = UINT_MAX;
 
+	if (!time)
+		return -EOPNOTSUPP;
+
 	ret = kstrtouint(buf, 10, &val);
 	if (ret)
 		return ret;
@@ -395,7 +408,7 @@ static const struct platform_device_id axp_pek_id_match[] = {
 	},
 	{
 		.name = "axp313a-pek",
-		.driver_data = (kernel_ulong_t)&axp20x_info,
+		.driver_data = (kernel_ulong_t)&axp313a_info,
 	},
 	{ /* sentinel */ }
 };
-- 
2.43.0