[MTD] m25p80 converted to mutex

Convert semaphore usage in m25p80 driver to mutex; mention another kind of
SPI flash chip that should be able to use this driver (given minor tweaks).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

drivers/mtd/devices/m25p80.c

@@ -19,16 +19,17 @@
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/interrupt.h>
-#include <linux/interrupt.h>
+#include <linux/mutex.h>
+
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
+
 #include <linux/spi/spi.h>
 #include <linux/spi/flash.h>
 
-#include <asm/semaphore.h>
-
 
 /* NOTE: AT 25F and SST 25LF series are very similar,
+ * as are other newer Atmel dataflash chips (AT26),
  * but commands for sector erase and chip id differ...
  */
 
@@ -65,7 +66,7 @@
 
 struct m25p {
 	struct spi_device	*spi;
-	struct semaphore	lock;
+	struct mutex		lock;
 	struct mtd_info		mtd;
 	unsigned		partitioned;
 	u8			command[4];
@@ -201,21 +202,21 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
 	addr = instr->addr;
 	len = instr->len;
 
-  	down(&flash->lock);
+	mutex_lock(&flash->lock);
 
 	/* now erase those sectors */
 	while (len) {
 		if (erase_sector(flash, addr)) {
 			instr->state = MTD_ERASE_FAILED;
-			up(&flash->lock);
+			mutex_unlock(&flash->lock);
 			return -EIO;
 		}
 
 		addr += mtd->erasesize;
 		len -= mtd->erasesize;
 	}
 
-  	up(&flash->lock);
+	mutex_unlock(&flash->lock);
 
 	instr->state = MTD_ERASE_DONE;
 	mtd_erase_callback(instr);
@@ -260,12 +261,12 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
 	if (retlen)
 		*retlen = 0;
 
-	down(&flash->lock);
+	mutex_lock(&flash->lock);
 
 	/* Wait till previous write/erase is done. */
 	if (wait_till_ready(flash)) {
 		/* REVISIT status return?? */
-		up(&flash->lock);
+		mutex_unlock(&flash->lock);
 		return 1;
 	}
 
@@ -281,7 +282,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
 
 	*retlen = m.actual_length - sizeof(flash->command);
 
-  	up(&flash->lock);
+	mutex_unlock(&flash->lock);
 
 	return 0;
 }
@@ -323,7 +324,7 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
 	t[1].tx_buf = buf;
 	spi_message_add_tail(&t[1], &m);
 
-  	down(&flash->lock);
+	mutex_lock(&flash->lock);
 
 	/* Wait until finished previous write command. */
 	if (wait_till_ready(flash))
@@ -381,10 +382,10 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
 			if (retlen)
 				*retlen += m.actual_length
 					- sizeof(flash->command);
-	        }
- 	}
+		}
+	}
 
-	up(&flash->lock);
+	mutex_unlock(&flash->lock);
 
 	return 0;
 }
@@ -405,7 +406,7 @@ struct flash_info {
 };
 
 static struct flash_info __devinitdata m25p_data [] = {
-	/* REVISIT: fill in JEDEC ids, for parts that have them */
+	/* JEDEC id zero means "has no ID" */
 	{ "m25p05", 0x05, 0x2010, 32 * 1024, 2 },
 	{ "m25p10", 0x10, 0x2011, 32 * 1024, 4 },
 	{ "m25p20", 0x11, 0x2012, 64 * 1024, 4 },
@@ -456,7 +457,7 @@ static int __devinit m25p_probe(struct spi_device *spi)
 		return -ENOMEM;
 
 	flash->spi = spi;
-	init_MUTEX(&flash->lock);
+	mutex_init(&flash->lock);
 	dev_set_drvdata(&spi->dev, flash);
 
 	if (data->name)