---

yaml
---
r: 304020
b: refs/heads/master
c: b4161f0
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 985087dbcb0265f46e8651fdc7e974f8a7184423
+refs/heads/master: b4161f0bb5f815ca6d8108062b8e3b650c18fe39

trunk/drivers/misc/eeprom/at25.c

@@ -50,6 +50,7 @@ struct at25_data {
 #define	AT25_SR_BP1	0x08
 #define	AT25_SR_WPEN	0x80		/* writeprotect enable */
 
+#define	AT25_INSTR_BIT3	0x08		/* Additional address bit in instr */
 
 #define EE_MAXADDRLEN	3		/* 24 bit addresses, up to 2 MBytes */
 
@@ -75,6 +76,7 @@ at25_ee_read(
 	ssize_t			status;
 	struct spi_transfer	t[2];
 	struct spi_message	m;
+	u8			instr;
 
 	if (unlikely(offset >= at25->bin.size))
 		return 0;
@@ -84,7 +86,12 @@ at25_ee_read(
 		return count;
 
 	cp = command;
-	*cp++ = AT25_READ;
+
+	instr = AT25_READ;
+	if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR)
+		if (offset >= (1U << (at25->addrlen * 8)))
+			instr |= AT25_INSTR_BIT3;
+	*cp++ = instr;
 
 	/* 8/16/24-bit address is written MSB first */
 	switch (at25->addrlen) {
@@ -167,14 +174,14 @@ at25_ee_write(struct at25_data *at25, const char *buf, loff_t off,
 	/* For write, rollover is within the page ... so we write at
 	 * most one page, then manually roll over to the next page.
 	 */
-	bounce[0] = AT25_WRITE;
 	mutex_lock(&at25->lock);
 	do {
 		unsigned long	timeout, retries;
 		unsigned	segment;
 		unsigned	offset = (unsigned) off;
-		u8		*cp = bounce + 1;
+		u8		*cp = bounce;
 		int		sr;
+		u8		instr;
 
 		*cp = AT25_WREN;
 		status = spi_write(at25->spi, cp, 1);
@@ -184,6 +191,12 @@ at25_ee_write(struct at25_data *at25, const char *buf, loff_t off,
 			break;
 		}
 
+		instr = AT25_WRITE;
+		if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR)
+			if (offset >= (1U << (at25->addrlen * 8)))
+				instr |= AT25_INSTR_BIT3;
+		*cp++ = instr;
+
 		/* 8/16/24-bit address is written MSB first */
 		switch (at25->addrlen) {
 		default:	/* case 3 */

trunk/include/linux/spi/eeprom.h

@@ -20,6 +20,16 @@ struct spi_eeprom {
 #define	EE_ADDR3	0x0004			/* 24 bit addrs */
 #define	EE_READONLY	0x0008			/* disallow writes */
 
+	/*
+	 * Certain EEPROMS have a size that is larger than the number of address
+	 * bytes would allow (e.g. like M95040 from ST that has 512 Byte size
+	 * but uses only one address byte (A0 to A7) for addressing.) For
+	 * the extra address bit (A8, A16 or A24) bit 3 of the instruction byte
+	 * is used. This instruction bit is normally defined as don't care for
+	 * other AT25 like chips.
+	 */
+#define EE_INSTR_BIT3_IS_ADDR	0x0010
+
 	/* for exporting this chip's data to other kernel code */
 	void (*setup)(struct memory_accessor *mem, void *context);
 	void *context;