1 files changed, 367 insertions, 217 deletions

diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index 99de6939cd5a..883dfd0ed658 100644
--- a/drivers/misc/eeprom/at25.c
+++ b/drivers/misc/eeprom/at25.c
@@ -1,40 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
- * at25.c -- support most SPI EEPROMs, such as Atmel AT25 models
+ * Driver for most of the SPI EEPROMs, such as Atmel AT25 models
+ * and Cypress FRAMs FM25 models.
  *
  * Copyright (C) 2006 David Brownell
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
  */
 
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/slab.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/property.h>
 #include <linux/sched.h>
+#include <linux/slab.h>
 
-#include <linux/nvmem-provider.h>
-#include <linux/spi/spi.h>
 #include <linux/spi/eeprom.h>
-#include <linux/property.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-mem.h>
+
+#include <linux/nvmem-provider.h>
 
 /*
- * NOTE: this is an *EEPROM* driver.  The vagaries of product naming
+ * NOTE: this is an *EEPROM* driver. The vagaries of product naming
  * mean that some AT25 products are EEPROMs, and others are FLASH.
  * Handle FLASH chips with the drivers/mtd/devices/m25p80.c driver,
  * not this one!
+ *
+ * EEPROMs that can be used with this driver include, for example:
+ *   AT25M02, AT25128B
  */
 
+#define	FM25_SN_LEN	8		/* serial number length */
+#define EE_MAXADDRLEN	3		/* 24 bit addresses, up to 2 MBytes */
+
 struct at25_data {
-	struct spi_device	*spi;
-	struct mutex		lock;
 	struct spi_eeprom	chip;
+	struct spi_mem		*spimem;
+	struct mutex		lock;
 	unsigned		addrlen;
 	struct nvmem_config	nvmem_config;
 	struct nvmem_device	*nvmem;
+	u8 sernum[FM25_SN_LEN];
 };
 
 #define	AT25_WREN	0x06		/* latch the write enable */
@@ -43,6 +52,9 @@ struct at25_data {
 #define	AT25_WRSR	0x01		/* write status register */
 #define	AT25_READ	0x03		/* read byte(s) */
 #define	AT25_WRITE	0x02		/* write byte(s)/sector */
+#define	FM25_SLEEP	0xb9		/* enter sleep mode */
+#define	FM25_RDID	0x9f		/* read device ID */
+#define	FM25_RDSN	0xc3		/* read S/N */
 
 #define	AT25_SR_nRDY	0x01		/* nRDY = write-in-progress */
 #define	AT25_SR_WEN	0x02		/* write enable (latched) */
@@ -50,11 +62,12 @@ 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	AT25_INSTR_BIT3	0x08		/* additional address bit in instr */
 
-#define EE_MAXADDRLEN	3		/* 24 bit addresses, up to 2 MBytes */
+#define	FM25_ID_LEN	9		/* ID length */
 
-/* Specs often allow 5 msec for a page write, sometimes 20 msec;
+/*
+ * Specs often allow 5ms for a page write, sometimes 20ms;
  * it's important to recover from write timeouts.
  */
 #define	EE_TIMEOUT	25
@@ -63,17 +76,29 @@ struct at25_data {
 
 #define	io_limit	PAGE_SIZE	/* bytes */
 
+/* Handle the address MSB as part of instruction byte */
+static u8 at25_instr(struct at25_data *at25, u8 instr, unsigned int off)
+{
+	if (!(at25->chip.flags & EE_INSTR_BIT3_IS_ADDR))
+		return instr;
+	if (off < BIT(at25->addrlen * 8))
+		return instr;
+	return instr | AT25_INSTR_BIT3;
+}
+
 static int at25_ee_read(void *priv, unsigned int offset,
 			void *val, size_t count)
 {
+	u8 *bounce __free(kfree) = kmalloc(min(count, io_limit), GFP_KERNEL);
 	struct at25_data *at25 = priv;
 	char *buf = val;
-	u8			command[EE_MAXADDRLEN + 1];
-	u8			*cp;
-	ssize_t			status;
-	struct spi_transfer	t[2];
-	struct spi_message	m;
-	u8			instr;
+	unsigned int msg_offset = offset;
+	size_t bytes_left = count;
+	size_t segment;
+	int status;
+
+	if (!bounce)
+		return -ENOMEM;
 
 	if (unlikely(offset >= at25->chip.byte_len))
 		return -EINVAL;
@@ -82,61 +107,126 @@ static int at25_ee_read(void *priv, unsigned int offset,
 	if (unlikely(!count))
 		return -EINVAL;
 
-	cp = command;
-
-	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) {
-	default:	/* case 3 */
-		*cp++ = offset >> 16;
-		/* fall through */
-	case 2:
-		*cp++ = offset >> 8;
-		/* fall through */
-	case 1:
-	case 0:	/* can't happen: for better codegen */
-		*cp++ = offset >> 0;
-	}
+	do {
+		struct spi_mem_op op;
 
-	spi_message_init(&m);
-	memset(t, 0, sizeof(t));
+		segment = min(bytes_left, io_limit);
 
-	t[0].tx_buf = command;
-	t[0].len = at25->addrlen + 1;
-	spi_message_add_tail(&t[0], &m);
+		op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(at25_instr(at25, AT25_READ,
+									     msg_offset), 1),
+						   SPI_MEM_OP_ADDR(at25->addrlen, msg_offset, 1),
+						   SPI_MEM_OP_NO_DUMMY,
+						   SPI_MEM_OP_DATA_IN(segment, bounce, 1));
 
-	t[1].rx_buf = buf;
-	t[1].len = count;
-	spi_message_add_tail(&t[1], &m);
+		status = spi_mem_adjust_op_size(at25->spimem, &op);
+		if (status)
+			return status;
+		segment = op.data.nbytes;
 
-	mutex_lock(&at25->lock);
+		mutex_lock(&at25->lock);
+		status = spi_mem_exec_op(at25->spimem, &op);
+		mutex_unlock(&at25->lock);
+		if (status)
+			return status;
+		memcpy(buf, bounce, segment);
 
-	/* Read it all at once.
-	 *
-	 * REVISIT that's potentially a problem with large chips, if
-	 * other devices on the bus need to be accessed regularly or
-	 * this chip is clocked very slowly
-	 */
-	status = spi_sync(at25->spi, &m);
-	dev_dbg(&at25->spi->dev, "read %zu bytes at %d --> %zd\n",
-		count, offset, status);
+		msg_offset += segment;
+		buf += segment;
+		bytes_left -= segment;
+	} while (bytes_left > 0);
 
-	mutex_unlock(&at25->lock);
-	return status;
+	dev_dbg(&at25->spimem->spi->dev, "read %zu bytes at %d\n",
+		count, offset);
+	return 0;
+}
+
+/*
+ * Read extra registers as ID or serial number
+ *
+ * Allow for the callers to provide @buf on stack (not necessary DMA-capable)
+ * by allocating a bounce buffer internally.
+ */
+static int fm25_aux_read(struct at25_data *at25, u8 *buf, uint8_t command,
+			 int len)
+{
+	u8 *bounce __free(kfree) = kmalloc(len, GFP_KERNEL);
+	struct spi_mem_op op;
+	int status;
+
+	if (!bounce)
+		return -ENOMEM;
+
+	op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(command, 1),
+					   SPI_MEM_OP_NO_ADDR,
+					   SPI_MEM_OP_NO_DUMMY,
+					   SPI_MEM_OP_DATA_IN(len, bounce, 1));
+
+	status = spi_mem_exec_op(at25->spimem, &op);
+	dev_dbg(&at25->spimem->spi->dev, "read %d aux bytes --> %d\n", len, status);
+	if (status)
+		return status;
+
+	memcpy(buf, bounce, len);
+
+	return 0;
+}
+
+static ssize_t sernum_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct at25_data *at25;
+
+	at25 = dev_get_drvdata(dev);
+	return sysfs_emit(buf, "%*ph\n", (int)sizeof(at25->sernum), at25->sernum);
+}
+static DEVICE_ATTR_RO(sernum);
+
+static struct attribute *sernum_attrs[] = {
+	&dev_attr_sernum.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(sernum);
+
+/*
+ * Poll Read Status Register with timeout
+ *
+ * Return:
+ * 0, if the chip is ready
+ * [positive] Status Register value as-is, if the chip is busy
+ * [negative] error code in case of read failure
+ */
+static int at25_wait_ready(struct at25_data *at25)
+{
+	u8 *bounce __free(kfree) = kmalloc(1, GFP_KERNEL);
+	struct spi_mem_op op;
+	int status;
+
+	if (!bounce)
+		return -ENOMEM;
+
+	op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(AT25_RDSR, 1),
+					   SPI_MEM_OP_NO_ADDR,
+					   SPI_MEM_OP_NO_DUMMY,
+					   SPI_MEM_OP_DATA_IN(1, bounce, 1));
+
+	read_poll_timeout(spi_mem_exec_op, status,
+			  status || !(bounce[0] & AT25_SR_nRDY), false,
+			  USEC_PER_MSEC, USEC_PER_MSEC * EE_TIMEOUT,
+			  at25->spimem, &op);
+	if (status < 0)
+		return status;
+	if (!(bounce[0] & AT25_SR_nRDY))
+		return 0;
+
+	return bounce[0];
 }
 
 static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
 {
+	u8 *bounce __free(kfree) = kmalloc(min(count, io_limit), GFP_KERNEL);
 	struct at25_data *at25 = priv;
 	const char *buf = val;
-	int			status = 0;
-	unsigned		buf_size;
-	u8			*bounce;
+	unsigned int buf_size;
+	int status;
 
 	if (unlikely(off >= at25->chip.byte_len))
 		return -EFBIG;
@@ -145,93 +235,73 @@ static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
 	if (unlikely(!count))
 		return -EINVAL;
 
-	/* Temp buffer starts with command and address */
 	buf_size = at25->chip.page_size;
-	if (buf_size > io_limit)
-		buf_size = io_limit;
-	bounce = kmalloc(buf_size + at25->addrlen + 1, GFP_KERNEL);
+
 	if (!bounce)
 		return -ENOMEM;
 
-	/* For write, rollover is within the page ... so we write at
+	/*
+	 * For write, rollover is within the page ... so we write at
 	 * most one page, then manually roll over to the next page.
 	 */
-	mutex_lock(&at25->lock);
+	guard(mutex)(&at25->lock);
 	do {
-		unsigned long	timeout, retries;
-		unsigned	segment;
-		unsigned	offset = (unsigned) off;
-		u8		*cp = bounce;
-		int		sr;
-		u8		instr;
-
-		*cp = AT25_WREN;
-		status = spi_write(at25->spi, cp, 1);
-		if (status < 0) {
-			dev_dbg(&at25->spi->dev, "WREN --> %d\n", status);
-			break;
-		}
+		struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(AT25_WREN, 1),
+						  SPI_MEM_OP_NO_ADDR,
+						  SPI_MEM_OP_NO_DUMMY,
+						  SPI_MEM_OP_NO_DATA);
+		unsigned int segment;
 
-		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 */
-			*cp++ = offset >> 16;
-			/* fall through */
-		case 2:
-			*cp++ = offset >> 8;
-			/* fall through */
-		case 1:
-		case 0:	/* can't happen: for better codegen */
-			*cp++ = offset >> 0;
+		status = spi_mem_exec_op(at25->spimem, &op);
+		if (status < 0) {
+			dev_dbg(&at25->spimem->spi->dev, "WREN --> %d\n", status);
+			return status;
 		}
 
 		/* Write as much of a page as we can */
-		segment = buf_size - (offset % buf_size);
+		segment = buf_size - (off % buf_size);
 		if (segment > count)
 			segment = count;
-		memcpy(cp, buf, segment);
-		status = spi_write(at25->spi, bounce,
-				segment + at25->addrlen + 1);
-		dev_dbg(&at25->spi->dev, "write %u bytes at %u --> %d\n",
-			segment, offset, status);
-		if (status < 0)
-			break;
-
-		/* REVISIT this should detect (or prevent) failed writes
-		 * to readonly sections of the EEPROM...
+		if (segment > io_limit)
+			segment = io_limit;
+
+		op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(at25_instr(at25, AT25_WRITE, off),
+								  1),
+						   SPI_MEM_OP_ADDR(at25->addrlen, off, 1),
+						   SPI_MEM_OP_NO_DUMMY,
+						   SPI_MEM_OP_DATA_OUT(segment, bounce, 1));
+
+		status = spi_mem_adjust_op_size(at25->spimem, &op);
+		if (status)
+			return status;
+		segment = op.data.nbytes;
+
+		memcpy(bounce, buf, segment);
+
+		status = spi_mem_exec_op(at25->spimem, &op);
+		dev_dbg(&at25->spimem->spi->dev, "write %u bytes at %u --> %d\n",
+			segment, off, status);
+		if (status)
+			return status;
+
+		/*
+		 * REVISIT this should detect (or prevent) failed writes
+		 * to read-only sections of the EEPROM...
 		 */
 
-		/* Wait for non-busy status */
-		timeout = jiffies + msecs_to_jiffies(EE_TIMEOUT);
-		retries = 0;
-		do {
-
-			sr = spi_w8r8(at25->spi, AT25_RDSR);
-			if (sr < 0 || (sr & AT25_SR_nRDY)) {
-				dev_dbg(&at25->spi->dev,
-					"rdsr --> %d (%02x)\n", sr, sr);
-				/* at HZ=100, this is sloooow */
-				msleep(1);
-				continue;
-			}
-			if (!(sr & AT25_SR_nRDY))
-				break;
-		} while (retries++ < 3 || time_before_eq(jiffies, timeout));
-
-		if ((sr < 0) || (sr & AT25_SR_nRDY)) {
-			dev_err(&at25->spi->dev,
+		status = at25_wait_ready(at25);
+		if (status < 0) {
+			dev_err_probe(&at25->spimem->spi->dev, status,
+				      "Read Status Redister command failed\n");
+			return status;
+		}
+		if (status) {
+			dev_dbg(&at25->spimem->spi->dev,
+				"Status %02x\n", status);
+			dev_err(&at25->spimem->spi->dev,
 				"write %u bytes offset %u, timeout after %u msecs\n",
-				segment, offset,
-				jiffies_to_msecs(jiffies -
-					(timeout - EE_TIMEOUT)));
-			status = -ETIMEDOUT;
-			break;
+				segment, off, EE_TIMEOUT);
+			return -ETIMEDOUT;
 		}
 
 		off += segment;
@@ -240,9 +310,6 @@ static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
 
 	} while (count > 0);
 
-	mutex_unlock(&at25->lock);
-
-	kfree(bounce);
 	return status;
 }
 
@@ -251,38 +318,41 @@ static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
 static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip)
 {
 	u32 val;
+	int err;
 
-	memset(chip, 0, sizeof(*chip));
-	strncpy(chip->name, "at25", sizeof(chip->name));
+	strscpy(chip->name, "at25", sizeof(chip->name));
 
-	if (device_property_read_u32(dev, "size", &val) == 0 ||
-	    device_property_read_u32(dev, "at25,byte-len", &val) == 0) {
-		chip->byte_len = val;
-	} else {
+	err = device_property_read_u32(dev, "size", &val);
+	if (err)
+		err = device_property_read_u32(dev, "at25,byte-len", &val);
+	if (err) {
 		dev_err(dev, "Error: missing \"size\" property\n");
-		return -ENODEV;
+		return err;
 	}
+	chip->byte_len = val;
 
-	if (device_property_read_u32(dev, "pagesize", &val) == 0 ||
-	    device_property_read_u32(dev, "at25,page-size", &val) == 0) {
-		chip->page_size = (u16)val;
-	} else {
+	err = device_property_read_u32(dev, "pagesize", &val);
+	if (err)
+		err = device_property_read_u32(dev, "at25,page-size", &val);
+	if (err) {
 		dev_err(dev, "Error: missing \"pagesize\" property\n");
-		return -ENODEV;
+		return err;
 	}
+	chip->page_size = val;
 
-	if (device_property_read_u32(dev, "at25,addr-mode", &val) == 0) {
+	err = device_property_read_u32(dev, "address-width", &val);
+	if (err) {
+		err = device_property_read_u32(dev, "at25,addr-mode", &val);
+		if (err) {
+			dev_err(dev, "Error: missing \"address-width\" property\n");
+			return err;
+		}
 		chip->flags = (u16)val;
 	} else {
-		if (device_property_read_u32(dev, "address-width", &val)) {
-			dev_err(dev,
-				"Error: missing \"address-width\" property\n");
-			return -ENODEV;
-		}
 		switch (val) {
 		case 9:
 			chip->flags |= EE_INSTR_BIT3_IS_ADDR;
-			/* fall through */
+			fallthrough;
 		case 8:
 			chip->flags |= EE_ADDR1;
 			break;
@@ -304,57 +374,139 @@ static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip)
 	return 0;
 }
 
-static int at25_probe(struct spi_device *spi)
+static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip)
 {
-	struct at25_data	*at25 = NULL;
-	struct spi_eeprom	chip;
-	int			err;
-	int			sr;
-	int			addrlen;
+	struct at25_data *at25 = container_of(chip, struct at25_data, chip);
+	u8 sernum[FM25_SN_LEN];
+	u8 id[FM25_ID_LEN];
+	u32 val;
+	int i;
 
-	/* Chip description */
-	if (!spi->dev.platform_data) {
-		err = at25_fw_to_chip(&spi->dev, &chip);
-		if (err)
-			return err;
-	} else
-		chip = *(struct spi_eeprom *)spi->dev.platform_data;
+	strscpy(chip->name, "fm25", sizeof(chip->name));
 
-	/* For now we only support 8/16/24 bit addressing */
-	if (chip.flags & EE_ADDR1)
-		addrlen = 1;
-	else if (chip.flags & EE_ADDR2)
-		addrlen = 2;
-	else if (chip.flags & EE_ADDR3)
-		addrlen = 3;
-	else {
-		dev_dbg(&spi->dev, "unsupported address type\n");
-		return -EINVAL;
-	}
+	if (!device_property_read_u32(dev, "size", &val)) {
+		chip->byte_len = val;
+	} else {
+		/* Get ID of chip */
+		fm25_aux_read(at25, id, FM25_RDID, FM25_ID_LEN);
+		/* There are inside-out FRAM variations, detect them and reverse the ID bytes */
+		if (id[6] == 0x7f && id[2] == 0xc2)
+			for (i = 0; i < ARRAY_SIZE(id) / 2; i++) {
+				u8 tmp = id[i];
+				int j = ARRAY_SIZE(id) - i - 1;
+
+				id[i] = id[j];
+				id[j] = tmp;
+			}
+		if (id[6] != 0xc2) {
+			dev_err(dev, "Error: no Cypress FRAM with device ID (manufacturer ID bank 7: %02x)\n", id[6]);
+			return -ENODEV;
+		}
 
-	/* Ping the chip ... the status register is pretty portable,
-	 * unlike probing manufacturer IDs.  We do expect that system
-	 * firmware didn't write it in the past few milliseconds!
-	 */
-	sr = spi_w8r8(spi, AT25_RDSR);
-	if (sr < 0 || sr & AT25_SR_nRDY) {
-		dev_dbg(&spi->dev, "rdsr --> %d (%02x)\n", sr, sr);
-		return -ENXIO;
+		switch (id[7]) {
+		case 0x21 ... 0x26:
+			chip->byte_len = BIT(id[7] - 0x21 + 4) * 1024;
+			break;
+		case 0x2a ... 0x30:
+			/* CY15B102QN ... CY15B116QN */
+			chip->byte_len = BIT(((id[7] >> 1) & 0xf) + 13);
+			break;
+		default:
+			dev_err(dev, "Error: unsupported size (id %02x)\n", id[7]);
+			return -ENODEV;
+		}
+
+		if (id[8]) {
+			fm25_aux_read(at25, sernum, FM25_RDSN, FM25_SN_LEN);
+			/* Swap byte order */
+			for (i = 0; i < FM25_SN_LEN; i++)
+				at25->sernum[i] = sernum[FM25_SN_LEN - 1 - i];
+		}
 	}
 
-	at25 = devm_kzalloc(&spi->dev, sizeof(struct at25_data), GFP_KERNEL);
+	if (chip->byte_len > 64 * 1024)
+		chip->flags |= EE_ADDR3;
+	else
+		chip->flags |= EE_ADDR2;
+
+	chip->page_size = PAGE_SIZE;
+	return 0;
+}
+
+static const struct of_device_id at25_of_match[] = {
+	{ .compatible = "atmel,at25" },
+	{ .compatible = "cypress,fm25" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, at25_of_match);
+
+static const struct spi_device_id at25_spi_ids[] = {
+	{ .name = "at25" },
+	{ .name = "fm25" },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, at25_spi_ids);
+
+static int at25_probe(struct spi_mem *mem)
+{
+	struct spi_device *spi = mem->spi;
+	struct spi_eeprom *pdata;
+	struct at25_data *at25;
+	bool is_fram;
+	int err;
+
+	at25 = devm_kzalloc(&spi->dev, sizeof(*at25), GFP_KERNEL);
 	if (!at25)
 		return -ENOMEM;
 
+	at25->spimem = mem;
+
+	/*
+	 * Ping the chip ... the status register is pretty portable,
+	 * unlike probing manufacturer IDs.
+	 */
+	err = at25_wait_ready(at25);
+	if (err < 0)
+		return dev_err_probe(&spi->dev, err, "Read Status Register command failed\n");
+	if (err) {
+		dev_err(&spi->dev, "Not ready (%02x)\n", err);
+		return -ENXIO;
+	}
+
 	mutex_init(&at25->lock);
-	at25->chip = chip;
-	at25->spi = spi;
 	spi_set_drvdata(spi, at25);
-	at25->addrlen = addrlen;
 
+	is_fram = fwnode_device_is_compatible(dev_fwnode(&spi->dev), "cypress,fm25");
+
+	/* Chip description */
+	pdata = dev_get_platdata(&spi->dev);
+	if (pdata) {
+		at25->chip = *pdata;
+	} else {
+		if (is_fram)
+			err = at25_fram_to_chip(&spi->dev, &at25->chip);
+		else
+			err = at25_fw_to_chip(&spi->dev, &at25->chip);
+		if (err)
+			return err;
+	}
+
+	/* For now we only support 8/16/24 bit addressing */
+	if (at25->chip.flags & EE_ADDR1)
+		at25->addrlen = 1;
+	else if (at25->chip.flags & EE_ADDR2)
+		at25->addrlen = 2;
+	else if (at25->chip.flags & EE_ADDR3)
+		at25->addrlen = 3;
+	else {
+		dev_dbg(&spi->dev, "unsupported address type\n");
+		return -EINVAL;
+	}
+
+	at25->nvmem_config.type = is_fram ? NVMEM_TYPE_FRAM : NVMEM_TYPE_EEPROM;
 	at25->nvmem_config.name = dev_name(&spi->dev);
 	at25->nvmem_config.dev = &spi->dev;
-	at25->nvmem_config.read_only = chip.flags & EE_READONLY;
+	at25->nvmem_config.read_only = at25->chip.flags & EE_READONLY;
 	at25->nvmem_config.root_only = true;
 	at25->nvmem_config.owner = THIS_MODULE;
 	at25->nvmem_config.compat = true;
@@ -362,42 +514,40 @@ static int at25_probe(struct spi_device *spi)
 	at25->nvmem_config.reg_read = at25_ee_read;
 	at25->nvmem_config.reg_write = at25_ee_write;
 	at25->nvmem_config.priv = at25;
-	at25->nvmem_config.stride = 4;
+	at25->nvmem_config.stride = 1;
 	at25->nvmem_config.word_size = 1;
-	at25->nvmem_config.size = chip.byte_len;
+	at25->nvmem_config.size = at25->chip.byte_len;
 
 	at25->nvmem = devm_nvmem_register(&spi->dev, &at25->nvmem_config);
 	if (IS_ERR(at25->nvmem))
 		return PTR_ERR(at25->nvmem);
 
-	dev_info(&spi->dev, "%d %s %s eeprom%s, pagesize %u\n",
-		(chip.byte_len < 1024) ? chip.byte_len : (chip.byte_len / 1024),
-		(chip.byte_len < 1024) ? "Byte" : "KByte",
-		at25->chip.name,
-		(chip.flags & EE_READONLY) ? " (readonly)" : "",
-		at25->chip.page_size);
+	dev_info(&spi->dev, "%d %s %s %s%s, pagesize %u\n",
+		 (at25->chip.byte_len < 1024) ?
+			at25->chip.byte_len : (at25->chip.byte_len / 1024),
+		 (at25->chip.byte_len < 1024) ? "Byte" : "KByte",
+		 at25->chip.name, is_fram ? "fram" : "eeprom",
+		 (at25->chip.flags & EE_READONLY) ? " (readonly)" : "",
+		 at25->chip.page_size);
 	return 0;
 }
 
 /*-------------------------------------------------------------------------*/
 
-static const struct of_device_id at25_of_match[] = {
-	{ .compatible = "atmel,at25", },
-	{ }
-};
-MODULE_DEVICE_TABLE(of, at25_of_match);
-
-static struct spi_driver at25_driver = {
-	.driver = {
-		.name		= "at25",
-		.of_match_table = at25_of_match,
+static struct spi_mem_driver at25_driver = {
+	.spidrv = {
+		.driver = {
+			.name		= "at25",
+			.of_match_table = at25_of_match,
+			.dev_groups	= sernum_groups,
+		},
+		.id_table	= at25_spi_ids,
 	},
 	.probe		= at25_probe,
 };
 
-module_spi_driver(at25_driver);
+module_spi_mem_driver(at25_driver);
 
 MODULE_DESCRIPTION("Driver for most SPI EEPROMs");
 MODULE_AUTHOR("David Brownell");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("spi:at25");