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

[Steven Feng <steven@joint-cloud.com>]

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.

For AXP313A, the sysfs attributes (startup/shutdown) are hidden using
the is_visible callback, as they are not supported by the hardware.

Signed-off-by: Steven Feng <steven@joint-cloud.com>
---
Changes in v3:
- Use is_visible to hide attributes instead of returning -EOPNOTSUPP
- Corrected author name from "steven" to "Steven Feng"

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

v2: https://lore.kernel.org/all/tencent_48A497E0CA81323CFB6C7CB84428019A8707@qq.com/
v1: https://lore.kernel.org/all/tencent_5F1FF80489E702360F352F889570656BF608@qq.com/
---
 drivers/input/misc/axp20x-pek.c | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/drivers/input/misc/axp20x-pek.c b/drivers/input/misc/axp20x-pek.c
index d4e2fc9a937f..964b39817af9 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)
@@ -193,7 +200,28 @@ static struct attribute *axp20x_attrs[] = {
 	&dev_attr_shutdown.attr,
 	NULL,
 };
-ATTRIBUTE_GROUPS(axp20x);
+
+static umode_t axp20x_attr_is_visible(struct kobject *kobj,
+				      struct attribute *attr, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct axp20x_pek *axp20x_pek = dev_get_drvdata(dev);
+
+	if (!axp20x_pek->info->startup_time)
+		return 0;
+
+	return attr->mode;
+}
+
+static const struct attribute_group axp20x_group = {
+	.attrs = axp20x_attrs,
+	.is_visible = axp20x_attr_is_visible,
+};
+
+static const struct attribute_group *axp20x_groups[] = {
+	&axp20x_group,
+	NULL,
+};
 
 static irqreturn_t axp20x_pek_irq(int irq, void *pwr)
 {
@@ -395,7 +423,7 @@ 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