[U-Boot] [PATCH v2 8/9] WIP: x86: gpio: Handle the case where reading a GPIO fails
Simon Glass
sjg at chromium.org
Sat Aug 22 23:59:00 CEST 2015
It should be possible to read an output GPIO. For now it is not clear
how to do this. Perhaps the driver should be adjusted to use memory-mapped
access throughout. For now, return an error to avoid confusion.
Not to apply.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v2: None
drivers/gpio/intel_ich6_gpio.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/gpio/intel_ich6_gpio.c b/drivers/gpio/intel_ich6_gpio.c
index 67bf0a2..5cc86d7 100644
--- a/drivers/gpio/intel_ich6_gpio.c
+++ b/drivers/gpio/intel_ich6_gpio.c
@@ -195,6 +195,14 @@ static int _ich6_gpio_set_direction(uint16_t base, unsigned offset, int dir)
return 0;
}
+static int _ich6_gpio_get_direction(uint16_t base, unsigned offset)
+{
+ u32 val;
+
+ val = inl(base);
+ return !(val & (1UL << offset));
+}
+
static int _gpio_ich6_pinctrl_cfg_pin(s32 gpiobase, s32 iobase, int pin_node)
{
u32 gpio_offset[2];
@@ -432,6 +440,13 @@ static int ich6_gpio_get_value(struct udevice *dev, unsigned offset)
u32 tmplong;
int r;
+ /*
+ * TODO: Mirror this register since reading only works when it is an
+ * input, Alternatively figure out how to make the hardware work with
+ * this.
+ */
+ if (_ich6_gpio_get_direction(bank->io_sel, offset))
+ return -EIO;
tmplong = inl(bank->lvl);
r = (tmplong & (1UL << offset)) ? 1 : 0;
return r;
--
2.5.0.457.gab17608
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