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authorMike Frysinger <vapier@gentoo.org>2010-07-21 13:38:02 -0400
committerHeiko Schocher <hs@denx.de>2010-07-22 08:03:47 +0200
commit793b5726f7e998c7cec93ea5ee7910dd6ddb1e5e (patch)
tree5568b9f089ea3ef901098741c964b3d7a5b65c6b /drivers
parent1f82ff4777f360e92aa37bbbed647f7b9d9d2044 (diff)
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i2c: soft_i2c: add simple GPIO implementation
Since the vast majority of GPIO I2C implementations behave the same way, support the common GPIO framework with default settings. This adds two new defines CONFIG_SOFT_I2C_GPIO_{SCL,SDA} so that boards which want GPIO I2C support need only define these. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Tested-by: Thomas Chou <thomas@wytron.com.tw>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/i2c/soft_i2c.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/i2c/soft_i2c.c b/drivers/i2c/soft_i2c.c
index e0cf1e1..1a1809a 100644
--- a/drivers/i2c/soft_i2c.c
+++ b/drivers/i2c/soft_i2c.c
@@ -51,6 +51,58 @@
#endif
#include <i2c.h>
+#if defined(CONFIG_SOFT_I2C_GPIO_SCL)
+# include <asm/gpio.h>
+
+# ifndef I2C_GPIO_SYNC
+# define I2C_GPIO_SYNC
+# endif
+
+# ifndef I2C_INIT
+# define I2C_INIT \
+ do { \
+ gpio_request(CONFIG_SOFT_I2C_GPIO_SCL, "soft_i2c"); \
+ gpio_request(CONFIG_SOFT_I2C_GPIO_SDA, "soft_i2c"); \
+ } while (0)
+# endif
+
+# ifndef I2C_ACTIVE
+# define I2C_ACTIVE do { } while (0)
+# endif
+
+# ifndef I2C_TRISTATE
+# define I2C_TRISTATE do { } while (0)
+# endif
+
+# ifndef I2C_READ
+# define I2C_READ gpio_get_value(CONFIG_SOFT_I2C_GPIO_SDA)
+# endif
+
+# ifndef I2C_SDA
+# define I2C_SDA(bit) \
+ do { \
+ if (bit) \
+ gpio_direction_input(CONFIG_SOFT_I2C_GPIO_SDA); \
+ else \
+ gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SDA, 0); \
+ I2C_GPIO_SYNC; \
+ } while (0)
+# endif
+
+# ifndef I2C_SCL
+# define I2C_SCL(bit) \
+ do { \
+ gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SCL, bit); \
+ I2C_GPIO_SYNC; \
+ } while (0)
+# endif
+
+# ifndef I2C_DELAY
+# define I2C_DELAY udelay(5) /* 1/4 I2C clock duration */
+# endif
+
+#endif
+
/* #define DEBUG_I2C */
#ifdef DEBUG_I2C