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authorBin Meng <bmeng.cn@gmail.com>2017-05-07 19:52:29 -0700
committerBin Meng <bmeng.cn@gmail.com>2017-05-17 17:13:06 +0800
commit770ee0174223e824a721f5f164cc8b2bf7473189 (patch)
tree0de6de27fe1f7ee3d15aa9333ac2011d75a544f7 /drivers/gpio
parent4759dffe23460d39d8e92c01013b00a3587e2112 (diff)
downloadu-boot-770ee0174223e824a721f5f164cc8b2bf7473189.tar.gz
x86: ich6_gpio: Add use-lvl-write-cache for I/O access mode
Add a device-tree property use-lvl-write-cache that will cause writes to lvl to be cached instead of read from lvl before each write. This is required on some platforms that have the register implemented as dual read/write (such as Baytrail). Prior to this fix the blue USB port on the Minnowboard Max was unusable since USB_HOST_EN0 was set high then immediately set low when USB_HOST_EN1 was written. This also resolves the 'gpio clear | set' command warning like: "Warning: value of pin is still 0" Signed-off-by: George McCollister <george.mccollister@gmail.com> <rebased on latest origin/master, fixed all baytrail boards> Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Stefan Roese <sr@denx.de> Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/intel_ich6_gpio.c30
1 files changed, 25 insertions, 5 deletions
diff --git a/drivers/gpio/intel_ich6_gpio.c b/drivers/gpio/intel_ich6_gpio.c
index 8b782260bc..0a9eb03fd0 100644
--- a/drivers/gpio/intel_ich6_gpio.c
+++ b/drivers/gpio/intel_ich6_gpio.c
@@ -46,22 +46,31 @@ struct ich6_bank_priv {
uint16_t use_sel;
uint16_t io_sel;
uint16_t lvl;
+ u32 lvl_write_cache;
+ bool use_lvl_write_cache;
};
#define GPIO_USESEL_OFFSET(x) (x)
#define GPIO_IOSEL_OFFSET(x) (x + 4)
#define GPIO_LVL_OFFSET(x) (x + 8)
-static int _ich6_gpio_set_value(uint16_t base, unsigned offset, int value)
+static int _ich6_gpio_set_value(struct ich6_bank_priv *bank, unsigned offset,
+ int value)
{
u32 val;
- val = inl(base);
+ if (bank->use_lvl_write_cache)
+ val = bank->lvl_write_cache;
+ else
+ val = inl(bank->lvl);
+
if (value)
val |= (1UL << offset);
else
val &= ~(1UL << offset);
- outl(val, base);
+ outl(val, bank->lvl);
+ if (bank->use_lvl_write_cache)
+ bank->lvl_write_cache = val;
return 0;
}
@@ -112,6 +121,7 @@ static int ich6_gpio_probe(struct udevice *dev)
struct ich6_bank_platdata *plat = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct ich6_bank_priv *bank = dev_get_priv(dev);
+ const void *prop;
uc_priv->gpio_count = GPIO_PER_BANK;
uc_priv->bank_name = plat->bank_name;
@@ -119,6 +129,14 @@ static int ich6_gpio_probe(struct udevice *dev)
bank->io_sel = plat->base_addr + 4;
bank->lvl = plat->base_addr + 8;
+ prop = fdt_getprop(gd->fdt_blob, dev->of_offset,
+ "use-lvl-write-cache", NULL);
+ if (prop)
+ bank->use_lvl_write_cache = true;
+ else
+ bank->use_lvl_write_cache = false;
+ bank->lvl_write_cache = 0;
+
return 0;
}
@@ -160,7 +178,7 @@ static int ich6_gpio_direction_output(struct udevice *dev, unsigned offset,
if (ret)
return ret;
- return _ich6_gpio_set_value(bank->lvl, offset, value);
+ return _ich6_gpio_set_value(bank, offset, value);
}
static int ich6_gpio_get_value(struct udevice *dev, unsigned offset)
@@ -170,6 +188,8 @@ static int ich6_gpio_get_value(struct udevice *dev, unsigned offset)
int r;
tmplong = inl(bank->lvl);
+ if (bank->use_lvl_write_cache)
+ tmplong |= bank->lvl_write_cache;
r = (tmplong & (1UL << offset)) ? 1 : 0;
return r;
}
@@ -178,7 +198,7 @@ static int ich6_gpio_set_value(struct udevice *dev, unsigned offset,
int value)
{
struct ich6_bank_priv *bank = dev_get_priv(dev);
- return _ich6_gpio_set_value(bank->lvl, offset, value);
+ return _ich6_gpio_set_value(bank, offset, value);
}
static int ich6_gpio_get_function(struct udevice *dev, unsigned offset)