Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / drivers / i2c / busses / i2c-bfin-twi.c

diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index fb26e5c67515b6e314823fd50001e989e62886a0..52b545a795f2ae6e533bf0920385623e8e6e1b04 100644 (file)
--- 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");