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authorBen Dooks <ben-linux@fluff.org>2011-01-13 01:26:12 +0300
committerBen Dooks <ben-linux@fluff.org>2011-01-13 01:26:12 +0300
commitdad92924ea4c9167e64a2835ec9310c73570b10b (patch)
treeb0a0c3dfb1abb7cbab7916eeacec7dbe4dc1e021 /drivers/i2c
parentadeaf46d311715deee9ae38ef1edb0d6b6fb0d55 (diff)
parent74f56c4ad4e4627862bddb0b8c3ab394e3c004f7 (diff)
downloadlinux-dad92924ea4c9167e64a2835ec9310c73570b10b.tar.xz
Merge branch 'for-2638/i2c/bfin2' into for-linus/i2c-2638
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-bfin-twi.c24
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index fb26e5c67515..52b545a795f2 100644
--- a/drivers/i2c/busses/i2c-bfin-twi.c
+++ b/drivers/i2c/busses/i2c-bfin-twi.c
@@ -20,6 +20,7 @@
#include <linux/completion.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
+#include <linux/delay.h>
#include <asm/blackfin.h>
#include <asm/portmux.h>
@@ -159,6 +160,27 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface,
if (mast_stat & BUFWRERR)
dev_dbg(&iface->adap.dev, "Buffer Write Error\n");
+ /* Faulty slave devices, may drive SDA low after a transfer
+ * finishes. To release the bus this code generates up to 9
+ * extra clocks until SDA is released.
+ */
+
+ if (read_MASTER_STAT(iface) & SDASEN) {
+ int cnt = 9;
+ do {
+ write_MASTER_CTL(iface, SCLOVR);
+ udelay(6);
+ write_MASTER_CTL(iface, 0);
+ udelay(6);
+ } while ((read_MASTER_STAT(iface) & SDASEN) && cnt--);
+
+ write_MASTER_CTL(iface, SDAOVR | SCLOVR);
+ udelay(6);
+ write_MASTER_CTL(iface, SDAOVR);
+ udelay(6);
+ write_MASTER_CTL(iface, 0);
+ }
+
/* If it is a quick transfer, only address without data,
* not an err, return 1.
*/
@@ -760,7 +782,7 @@ static void __exit i2c_bfin_twi_exit(void)
platform_driver_unregister(&i2c_bfin_twi_driver);
}
-module_init(i2c_bfin_twi_init);
+subsys_initcall(i2c_bfin_twi_init);
module_exit(i2c_bfin_twi_exit);
MODULE_AUTHOR("Bryan Wu, Sonic Zhang");