[PATCH v1 06/16] pinctrl: cy8c95x0: Avoid accessing reserved registers

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

The checks for vrtual registers in the cy8c95x0_readable_register()
and cy8c95x0_writeable_register() are not aligned and broken.

Fix that by explicitly avoiding reserved registers to be accessed.

Fixes: 71e4001a0455 ("pinctrl: pinctrl-cy8c95x0: Fix regcache")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
 drivers/pinctrl/pinctrl-cy8c95x0.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-cy8c95x0.c b/drivers/pinctrl/pinctrl-cy8c95x0.c
index e98eba17cd13..970b6842b05b 100644
--- a/drivers/pinctrl/pinctrl-cy8c95x0.c
+++ b/drivers/pinctrl/pinctrl-cy8c95x0.c
@@ -328,14 +328,14 @@ static int cypress_get_pin_mask(struct cy8c95x0_pinctrl *chip, unsigned int pin)
 static bool cy8c95x0_readable_register(struct device *dev, unsigned int reg)
 {
 	/*
-	 * Only 12 registers are present per port (see Table 6 in the
-	 * datasheet).
+	 * Only 12 registers are present per port (see Table 6 in the datasheet).
 	 */
-	if (reg >= CY8C95X0_VIRTUAL && (reg % MUXED_STRIDE) < 12)
-		return true;
+	if (reg >= CY8C95X0_VIRTUAL && (reg % MUXED_STRIDE) >= 12)
+		return false;
 
 	switch (reg) {
 	case 0x24 ... 0x27:
+	case 0x31 ... 0x3f:
 		return false;
 	default:
 		return true;
@@ -344,8 +344,11 @@ static bool cy8c95x0_readable_register(struct device *dev, unsigned int reg)
 
 static bool cy8c95x0_writeable_register(struct device *dev, unsigned int reg)
 {
-	if (reg >= CY8C95X0_VIRTUAL)
-		return true;
+	/*
+	 * Only 12 registers are present per port (see Table 6 in the datasheet).
+	 */
+	if (reg >= CY8C95X0_VIRTUAL && (reg % MUXED_STRIDE) >= 12)
+		return false;
 
 	switch (reg) {
 	case CY8C95X0_INPUT_(0) ... CY8C95X0_INPUT_(7):
@@ -353,6 +356,7 @@ static bool cy8c95x0_writeable_register(struct device *dev, unsigned int reg)
 	case CY8C95X0_DEVID:
 		return false;
 	case 0x24 ... 0x27:
+	case 0x31 ... 0x3f:
 		return false;
 	default:
 		return true;
-- 
2.43.0.rc1.1336.g36b5255a03ac