The controller has several register bits describing access control
information for a given GPIO pin. When SCR_SEC_[R|W]EN is unset, it
means we have full read/write access to all the registers for given GPIO
pin. When SCR_SEC[R|W]EN is set, it means we need to further check the
accompanying SCR_SEC_G1[R|W] bit to determine read/write access to all
the registers for given GPIO pin.
This check was previously declaring that a GPIO pin was accessible
only if either of the following conditions were met:
- SCR_SEC_REN + SCR_SEC_WEN both set
or
- SCR_SEC_REN + SCR_SEC_WEN both set and
SCR_SEC_G1R + SCR_SEC_G1W both set
Update the check to properly handle cases where only one of
SCR_SEC_REN or SCR_SEC_WEN is set.
Fixes: b2b56a163230 ("gpio: tegra186: Check GPIO pin permission before access.")
Signed-off-by: Prathamesh Shete <pshete@xxxxxxxxxx>
---
drivers/gpio/gpio-tegra186.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/drivers/gpio/gpio-tegra186.c b/drivers/gpio/gpio-tegra186.c
index d87dd06db40d..54c8b02eec22 100644
--- a/drivers/gpio/gpio-tegra186.c
+++ b/drivers/gpio/gpio-tegra186.c
@@ -36,12 +36,10 @@
#define TEGRA186_GPIO_SCR_SEC_REN BIT(27)
#define TEGRA186_GPIO_SCR_SEC_G1W BIT(9)
#define TEGRA186_GPIO_SCR_SEC_G1R BIT(1)
-#define TEGRA186_GPIO_FULL_ACCESS (TEGRA186_GPIO_SCR_SEC_WEN | \
- TEGRA186_GPIO_SCR_SEC_REN | \
- TEGRA186_GPIO_SCR_SEC_G1R | \
+#define TEGRA186_GPIO_READ_ACCESS (TEGRA186_GPIO_SCR_SEC_REN | \
+ TEGRA186_GPIO_SCR_SEC_G1R)
+#define TEGRA186_GPIO_WRITE_ACCESS (TEGRA186_GPIO_SCR_SEC_WEN | \
TEGRA186_GPIO_SCR_SEC_G1W)
-#define TEGRA186_GPIO_SCR_SEC_ENABLE (TEGRA186_GPIO_SCR_SEC_WEN | \
- TEGRA186_GPIO_SCR_SEC_REN)
/* control registers */
#define TEGRA186_GPIO_ENABLE_CONFIG 0x00
@@ -177,10 +175,18 @@ static inline bool tegra186_gpio_is_accessible(struct tegra_gpio *gpio, unsigned
value = __raw_readl(secure + TEGRA186_GPIO_SCR);
- if ((value & TEGRA186_GPIO_SCR_SEC_ENABLE) == 0)
- return true;
+ /*
+ * When SCR_SEC_[R|W]EN is unset, then we have full read/write access to all the
+ * registers for given GPIO pin.
+ * When SCR_SEC[R|W]EN is set, then there is need to further check the accompanying
+ * SCR_SEC_G1[R|W] bit to determine read/write access to all the registers for given
+ * GPIO pin.
+ */
- if ((value & TEGRA186_GPIO_FULL_ACCESS) == TEGRA186_GPIO_FULL_ACCESS)
+ if (((value & TEGRA186_GPIO_SCR_SEC_REN) == 0 ||
+ (value & TEGRA186_GPIO_READ_ACCESS)) &&
+ ((value & TEGRA186_GPIO_SCR_SEC_WEN) == 0 ||
+ (value & TEGRA186_GPIO_WRITE_ACCESS)))
return true;
return false;
--
2.17.1
