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Merge branch 'for-2638/i2c/bfin2' into for-linus/i2c-2638

Ben Dooks 14 жил өмнө
parent
commit
dad92924ea

+ 23 - 1
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");