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authorAndreas Larsson <andreas@gaisler.com>2013-03-15 17:45:38 +0400
committerLinus Walleij <linus.walleij@linaro.org>2013-04-11 01:41:16 +0400
commit2b78f1e1389aef263071b9edf41c0980b092e601 (patch)
treea248dcde3ba8654b5a7dfda02861688f079cbc8e
parent43158441934fd9f1d2a2434c9eec1b682391a49b (diff)
downloadlinux-2b78f1e1389aef263071b9edf41c0980b092e601.tar.xz
gpio: gpio-generic: Add 16 and 32 bit big endian byte order support
There is no general support for 64-bit big endian accesses, so that is left unsupported. Signed-off-by: Andreas Larsson <andreas@gaisler.com> Acked-by: Anton Vorontsov <anton@enomsg.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r--drivers/gpio/gpio-generic.c56
-rw-r--r--include/linux/basic_mmio_gpio.h1
2 files changed, 48 insertions, 9 deletions
diff --git a/drivers/gpio/gpio-generic.c b/drivers/gpio/gpio-generic.c
index 05fcc0f247ca..42d470632aea 100644
--- a/drivers/gpio/gpio-generic.c
+++ b/drivers/gpio/gpio-generic.c
@@ -104,6 +104,26 @@ static unsigned long bgpio_read64(void __iomem *reg)
}
#endif /* BITS_PER_LONG >= 64 */
+static void bgpio_write16be(void __iomem *reg, unsigned long data)
+{
+ iowrite16be(data, reg);
+}
+
+static unsigned long bgpio_read16be(void __iomem *reg)
+{
+ return ioread16be(reg);
+}
+
+static void bgpio_write32be(void __iomem *reg, unsigned long data)
+{
+ iowrite32be(data, reg);
+}
+
+static unsigned long bgpio_read32be(void __iomem *reg)
+{
+ return ioread32be(reg);
+}
+
static unsigned long bgpio_pin2mask(struct bgpio_chip *bgc, unsigned int pin)
{
return 1 << pin;
@@ -249,7 +269,8 @@ static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val)
static int bgpio_setup_accessors(struct device *dev,
struct bgpio_chip *bgc,
- bool be)
+ bool bit_be,
+ bool byte_be)
{
switch (bgc->bits) {
@@ -258,17 +279,33 @@ static int bgpio_setup_accessors(struct device *dev,
bgc->write_reg = bgpio_write8;
break;
case 16:
- bgc->read_reg = bgpio_read16;
- bgc->write_reg = bgpio_write16;
+ if (byte_be) {
+ bgc->read_reg = bgpio_read16be;
+ bgc->write_reg = bgpio_write16be;
+ } else {
+ bgc->read_reg = bgpio_read16;
+ bgc->write_reg = bgpio_write16;
+ }
break;
case 32:
- bgc->read_reg = bgpio_read32;
- bgc->write_reg = bgpio_write32;
+ if (byte_be) {
+ bgc->read_reg = bgpio_read32be;
+ bgc->write_reg = bgpio_write32be;
+ } else {
+ bgc->read_reg = bgpio_read32;
+ bgc->write_reg = bgpio_write32;
+ }
break;
#if BITS_PER_LONG >= 64
case 64:
- bgc->read_reg = bgpio_read64;
- bgc->write_reg = bgpio_write64;
+ if (byte_be) {
+ dev_err(dev,
+ "64 bit big endian byte order unsupported\n");
+ return -EINVAL;
+ } else {
+ bgc->read_reg = bgpio_read64;
+ bgc->write_reg = bgpio_write64;
+ }
break;
#endif /* BITS_PER_LONG >= 64 */
default:
@@ -276,7 +313,7 @@ static int bgpio_setup_accessors(struct device *dev,
return -EINVAL;
}
- bgc->pin2mask = be ? bgpio_pin2mask_be : bgpio_pin2mask;
+ bgc->pin2mask = bit_be ? bgpio_pin2mask_be : bgpio_pin2mask;
return 0;
}
@@ -385,7 +422,8 @@ int bgpio_init(struct bgpio_chip *bgc, struct device *dev,
if (ret)
return ret;
- ret = bgpio_setup_accessors(dev, bgc, flags & BGPIOF_BIG_ENDIAN);
+ ret = bgpio_setup_accessors(dev, bgc, flags & BGPIOF_BIG_ENDIAN,
+ flags & BGPIOF_BIG_ENDIAN_BYTE_ORDER);
if (ret)
return ret;
diff --git a/include/linux/basic_mmio_gpio.h b/include/linux/basic_mmio_gpio.h
index 1c504ca5bdb3..d8a97ec0e2b8 100644
--- a/include/linux/basic_mmio_gpio.h
+++ b/include/linux/basic_mmio_gpio.h
@@ -72,5 +72,6 @@ int bgpio_init(struct bgpio_chip *bgc, struct device *dev,
#define BGPIOF_BIG_ENDIAN BIT(0)
#define BGPIOF_UNREADABLE_REG_SET BIT(1) /* reg_set is unreadable */
#define BGPIOF_UNREADABLE_REG_DIR BIT(2) /* reg_dir is unreadable */
+#define BGPIOF_BIG_ENDIAN_BYTE_ORDER BIT(3)
#endif /* __BASIC_MMIO_GPIO_H */