From: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx> [ Upstream commit 1be1b23696b3d4b0231c694f5e0767b4471d33a9 ] The I2C_DETECT register is at IO port 0x1a7, which is outside the range passed to devm_ioport_map() for io_base, and was only working because there aren't actually any bounds checks for IO port accesses. Extending the range does not seem like a good solution here, as it would then conflict with the IO resource assigned to the I2C controller. As this is just a one-off access during probe, use a simple inb() instead. While we're at it, drop the unused define TQMX86_REG_I2C_INT_EN. Fixes: 2f17dd34ffed ("mfd: tqmx86: IO controller with I2C, Wachdog and GPIO") Signed-off-by: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx> Reviewed-by: Andrew Lunn <andrew@xxxxxxx> Signed-off-by: Lee Jones <lee@xxxxxxxxxx> Link: https://lore.kernel.org/r/e8300a30f0791afb67d79db8089fb6004855f378.1676892223.git.matthias.schiffer@xxxxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/mfd/tqmx86.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/mfd/tqmx86.c b/drivers/mfd/tqmx86.c index 7ae906ff8e353..31d0efb5aacf8 100644 --- a/drivers/mfd/tqmx86.c +++ b/drivers/mfd/tqmx86.c @@ -49,9 +49,8 @@ #define TQMX86_REG_IO_EXT_INT_MASK 0x3 #define TQMX86_REG_IO_EXT_INT_GPIO_SHIFT 4 -#define TQMX86_REG_I2C_DETECT 0x47 +#define TQMX86_REG_I2C_DETECT 0x1a7 #define TQMX86_REG_I2C_DETECT_SOFT 0xa5 -#define TQMX86_REG_I2C_INT_EN 0x49 static uint gpio_irq; module_param(gpio_irq, uint, 0); @@ -213,7 +212,12 @@ static int tqmx86_probe(struct platform_device *pdev) "Found %s - Board ID %d, PCB Revision %d, PLD Revision %d\n", board_name, board_id, rev >> 4, rev & 0xf); - i2c_det = ioread8(io_base + TQMX86_REG_I2C_DETECT); + /* + * The I2C_DETECT register is in the range assigned to the I2C driver + * later, so we don't extend TQMX86_IOSIZE. Use inb() for this one-off + * access instead of ioport_map + unmap. + */ + i2c_det = inb(TQMX86_REG_I2C_DETECT); if (gpio_irq_cfg) { io_ext_int_val = -- 2.39.2