drivers/mtd/devices/m25p80.c - kernel/msm-4.9 - Gitiles

 /*
  * MTD SPI driver for ST M25Pxx (and similar) serial flash chips
  *
  * Author: Mike Lavender, mike@steroidmicros.com
  *
  * Copyright (c) 2005, Intec Automation Inc.
  *
  * Some parts are based on lart.c by Abraham Van Der Merwe
  *
  * Cleaned up and generalized based on mtd_dataflash.c
  *
  * This code is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  */

 #include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/device.h>

 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>

 #include <linux/spi/spi.h>
 #include <linux/spi/flash.h>
 #include <linux/mtd/spi-nor.h>

 #define	MAX_CMD_SIZE		6
 struct m25p {
 	struct spi_device	*spi;
 	struct spi_nor		spi_nor;
 	struct mtd_info		mtd;
 	u8			command[MAX_CMD_SIZE];
 };

 static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
 {
 	struct m25p *flash = nor->priv;
 	struct spi_device *spi = flash->spi;
 	int ret;

 	ret = spi_write_then_read(spi, &code, 1, val, len);
 	if (ret < 0)
 		dev_err(&spi->dev, "error %d reading %x\n", ret, code);

 	return ret;
 }

 static void m25p_addr2cmd(struct spi_nor *nor, unsigned int addr, u8 *cmd)
 {
 	/* opcode is in cmd[0] */
 	cmd[1] = addr >> (nor->addr_width * 8 -  8);
 	cmd[2] = addr >> (nor->addr_width * 8 - 16);
 	cmd[3] = addr >> (nor->addr_width * 8 - 24);
 	cmd[4] = addr >> (nor->addr_width * 8 - 32);
 }

 static int m25p_cmdsz(struct spi_nor *nor)
 {
 	return 1 + nor->addr_width;
 }

 static int m25p80_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len,
 			int wr_en)
 {
 	struct m25p *flash = nor->priv;
 	struct spi_device *spi = flash->spi;

 	flash->command[0] = opcode;
 	if (buf)
 		memcpy(&flash->command[1], buf, len);

 	return spi_write(spi, flash->command, len + 1);
 }

 static void m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
 			size_t *retlen, const u_char *buf)
 {
 	struct m25p *flash = nor->priv;
 	struct spi_device *spi = flash->spi;
 	struct spi_transfer t[2] = {};
 	struct spi_message m;
 	int cmd_sz = m25p_cmdsz(nor);

 	spi_message_init(&m);

 	if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
 		cmd_sz = 1;

 	flash->command[0] = nor->program_opcode;
 	m25p_addr2cmd(nor, to, flash->command);

 	t[0].tx_buf = flash->command;
 	t[0].len = cmd_sz;
 	spi_message_add_tail(&t[0], &m);

 	t[1].tx_buf = buf;
 	t[1].len = len;
 	spi_message_add_tail(&t[1], &m);

 	spi_sync(spi, &m);

 	*retlen += m.actual_length - cmd_sz;
 }

 static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor)
 {
 	switch (nor->flash_read) {
 	case SPI_NOR_DUAL:
 		return 2;
 	case SPI_NOR_QUAD:
 		return 4;
 	default:
 		return 0;
 	}
 }

 /*
  * Read an address range from the nor chip.  The address range
  * may be any size provided it is within the physical boundaries.
  */
 static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
 			size_t *retlen, u_char *buf)
 {
 	struct m25p *flash = nor->priv;
 	struct spi_device *spi = flash->spi;
 	struct spi_transfer t[2];
 	struct spi_message m;
 	int dummy = nor->read_dummy;
 	int ret;

 	/* Wait till previous write/erase is done. */
 	ret = nor->wait_till_ready(nor);
 	if (ret)
 		return ret;

 	spi_message_init(&m);
 	memset(t, 0, (sizeof t));

 	flash->command[0] = nor->read_opcode;
 	m25p_addr2cmd(nor, from, flash->command);

 	t[0].tx_buf = flash->command;
 	t[0].len = m25p_cmdsz(nor) + dummy;
 	spi_message_add_tail(&t[0], &m);

 	t[1].rx_buf = buf;
 	t[1].rx_nbits = m25p80_rx_nbits(nor);
 	t[1].len = len;
 	spi_message_add_tail(&t[1], &m);

 	spi_sync(spi, &m);

 	*retlen = m.actual_length - m25p_cmdsz(nor) - dummy;
 	return 0;
 }

 static int m25p80_erase(struct spi_nor *nor, loff_t offset)
 {
 	struct m25p *flash = nor->priv;
 	int ret;

 	dev_dbg(nor->dev, "%dKiB at 0x%08x\n",
 		flash->mtd.erasesize / 1024, (u32)offset);

 	/* Wait until finished previous write command. */
 	ret = nor->wait_till_ready(nor);
 	if (ret)
 		return ret;

 	/* Send write enable, then erase commands. */
 	ret = nor->write_reg(nor, SPINOR_OP_WREN, NULL, 0, 0);
 	if (ret)
 		return ret;

 	/* Set up command buffer. */
 	flash->command[0] = nor->erase_opcode;
 	m25p_addr2cmd(nor, offset, flash->command);

 	spi_write(flash->spi, flash->command, m25p_cmdsz(nor));

 	return 0;
 }

 /*
  * board specific setup should have ensured the SPI clock used here
  * matches what the READ command supports, at least until this driver
  * understands FAST_READ (for clocks over 25 MHz).
  */
 static int m25p_probe(struct spi_device *spi)
 {
 	struct mtd_part_parser_data	ppdata;
 	struct flash_platform_data	*data;
 	const struct spi_device_id *id = NULL;
 	struct m25p *flash;
 	struct spi_nor *nor;
 	enum read_mode mode = SPI_NOR_NORMAL;
 	int ret;

 	data = dev_get_platdata(&spi->dev);

 	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
 	if (!flash)
 		return -ENOMEM;

 	nor = &flash->spi_nor;

 	/* install the hooks */
 	nor->read = m25p80_read;
 	nor->write = m25p80_write;
 	nor->erase = m25p80_erase;
 	nor->write_reg = m25p80_write_reg;
 	nor->read_reg = m25p80_read_reg;

 	nor->dev = &spi->dev;
 	nor->mtd = &flash->mtd;
 	nor->priv = flash;

 	spi_set_drvdata(spi, flash);
 	flash->mtd.priv = nor;
 	flash->spi = spi;

 	if (spi->mode & SPI_RX_QUAD)
 		mode = SPI_NOR_QUAD;
 	else if (spi->mode & SPI_RX_DUAL)
 		mode = SPI_NOR_DUAL;

 	if (data && data->name)
 		flash->mtd.name = data->name;

 	/* For some (historical?) reason many platforms provide two different
 	 * names in flash_platform_data: "name" and "type". Quite often name is
 	 * set to "m25p80" and then "type" provides a real chip name.
 	 * If that's the case, respect "type" and ignore a "name".
 	 */
 	if (data && data->type)
 		id = spi_nor_match_id(data->type);

 	/* If we didn't get name from platform, simply use "modalias". */
 	if (!id)
 		id = spi_get_device_id(spi);

 	ret = spi_nor_scan(nor, id, mode);
 	if (ret)
 		return ret;

 	ppdata.of_node = spi->dev.of_node;

 	return mtd_device_parse_register(&flash->mtd, NULL, &ppdata,
 			data ? data->parts : NULL,
 			data ? data->nr_parts : 0);
 }


 static int m25p_remove(struct spi_device *spi)
 {
 	struct m25p	*flash = spi_get_drvdata(spi);

 	/* Clean up MTD stuff. */
 	return mtd_device_unregister(&flash->mtd);
 }


 static struct spi_driver m25p80_driver = {
 	.driver = {
 		.name	= "m25p80",
 		.owner	= THIS_MODULE,
 	},
 	.id_table	= spi_nor_ids,
 	.probe	= m25p_probe,
 	.remove	= m25p_remove,

 	/* REVISIT: many of these chips have deep power-down modes, which
 	 * should clearly be entered on suspend() to minimize power use.
 	 * And also when they're otherwise idle...
 	 */
 };

 module_spi_driver(m25p80_driver);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Mike Lavender");
 MODULE_DESCRIPTION("MTD SPI driver for ST M25Pxx flash chips");
	/*
	* MTD SPI driver for ST M25Pxx (and similar) serial flash chips
	*
	* Author: Mike Lavender, mike@steroidmicros.com
	*
	* Copyright (c) 2005, Intec Automation Inc.
	*
	* Some parts are based on lart.c by Abraham Van Der Merwe
	*
	* Cleaned up and generalized based on mtd_dataflash.c
	*
	* This code is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	*/

	#include <linux/err.h>
	#include <linux/errno.h>
	#include <linux/module.h>
	#include <linux/device.h>

	#include <linux/mtd/mtd.h>
	#include <linux/mtd/partitions.h>

	#include <linux/spi/spi.h>
	#include <linux/spi/flash.h>
	#include <linux/mtd/spi-nor.h>

	#define MAX_CMD_SIZE 6
	struct m25p {
	struct spi_device *spi;
	struct spi_nor spi_nor;
	struct mtd_info mtd;
	u8 command[MAX_CMD_SIZE];
	};

	static int m25p80_read_reg(struct spi_nor nor, u8 code, u8 val, int len)
	{
	struct m25p *flash = nor->priv;
	struct spi_device *spi = flash->spi;
	int ret;

	ret = spi_write_then_read(spi, &code, 1, val, len);
	if (ret < 0)
	dev_err(&spi->dev, "error %d reading %x\n", ret, code);

	return ret;
	}

	static void m25p_addr2cmd(struct spi_nor nor, unsigned int addr, u8 cmd)
	{
	/* opcode is in cmd[0] */
	cmd[1] = addr >> (nor->addr_width * 8 - 8);
	cmd[2] = addr >> (nor->addr_width * 8 - 16);
	cmd[3] = addr >> (nor->addr_width * 8 - 24);
	cmd[4] = addr >> (nor->addr_width * 8 - 32);
	}

	static int m25p_cmdsz(struct spi_nor *nor)
	{
	return 1 + nor->addr_width;
	}

	static int m25p80_write_reg(struct spi_nor nor, u8 opcode, u8 buf, int len,
	int wr_en)
	{
	struct m25p *flash = nor->priv;
	struct spi_device *spi = flash->spi;

	flash->command[0] = opcode;
	if (buf)
	memcpy(&flash->command[1], buf, len);

	return spi_write(spi, flash->command, len + 1);
	}

	static void m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
	size_t retlen, const u_char buf)
	{
	struct m25p *flash = nor->priv;
	struct spi_device *spi = flash->spi;
	struct spi_transfer t[2] = {};
	struct spi_message m;
	int cmd_sz = m25p_cmdsz(nor);

	spi_message_init(&m);

	if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
	cmd_sz = 1;

	flash->command[0] = nor->program_opcode;
	m25p_addr2cmd(nor, to, flash->command);

	t[0].tx_buf = flash->command;
	t[0].len = cmd_sz;
	spi_message_add_tail(&t[0], &m);

	t[1].tx_buf = buf;
	t[1].len = len;
	spi_message_add_tail(&t[1], &m);

	spi_sync(spi, &m);

	*retlen += m.actual_length - cmd_sz;
	}

	static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor)
	{
	switch (nor->flash_read) {
	case SPI_NOR_DUAL:
	return 2;
	case SPI_NOR_QUAD:
	return 4;
	default:
	return 0;
	}
	}

	/*
	* Read an address range from the nor chip. The address range
	* may be any size provided it is within the physical boundaries.
	*/
	static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
	size_t retlen, u_char buf)
	{
	struct m25p *flash = nor->priv;
	struct spi_device *spi = flash->spi;
	struct spi_transfer t[2];
	struct spi_message m;
	int dummy = nor->read_dummy;
	int ret;

	/* Wait till previous write/erase is done. */
	ret = nor->wait_till_ready(nor);
	if (ret)
	return ret;

	spi_message_init(&m);
	memset(t, 0, (sizeof t));

	flash->command[0] = nor->read_opcode;
	m25p_addr2cmd(nor, from, flash->command);

	t[0].tx_buf = flash->command;
	t[0].len = m25p_cmdsz(nor) + dummy;
	spi_message_add_tail(&t[0], &m);

	t[1].rx_buf = buf;
	t[1].rx_nbits = m25p80_rx_nbits(nor);
	t[1].len = len;
	spi_message_add_tail(&t[1], &m);

	spi_sync(spi, &m);

	*retlen = m.actual_length - m25p_cmdsz(nor) - dummy;
	return 0;
	}

	static int m25p80_erase(struct spi_nor *nor, loff_t offset)
	{
	struct m25p *flash = nor->priv;
	int ret;

	dev_dbg(nor->dev, "%dKiB at 0x%08x\n",
	flash->mtd.erasesize / 1024, (u32)offset);

	/* Wait until finished previous write command. */
	ret = nor->wait_till_ready(nor);
	if (ret)
	return ret;

	/* Send write enable, then erase commands. */
	ret = nor->write_reg(nor, SPINOR_OP_WREN, NULL, 0, 0);
	if (ret)
	return ret;

	/* Set up command buffer. */
	flash->command[0] = nor->erase_opcode;
	m25p_addr2cmd(nor, offset, flash->command);

	spi_write(flash->spi, flash->command, m25p_cmdsz(nor));

	return 0;
	}

	/*
	* board specific setup should have ensured the SPI clock used here
	* matches what the READ command supports, at least until this driver
	* understands FAST_READ (for clocks over 25 MHz).
	*/
	static int m25p_probe(struct spi_device *spi)
	{
	struct mtd_part_parser_data ppdata;
	struct flash_platform_data *data;
	const struct spi_device_id *id = NULL;
	struct m25p *flash;
	struct spi_nor *nor;
	enum read_mode mode = SPI_NOR_NORMAL;
	int ret;

	data = dev_get_platdata(&spi->dev);

	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
	if (!flash)
	return -ENOMEM;

	nor = &flash->spi_nor;

	/* install the hooks */
	nor->read = m25p80_read;
	nor->write = m25p80_write;
	nor->erase = m25p80_erase;
	nor->write_reg = m25p80_write_reg;
	nor->read_reg = m25p80_read_reg;

	nor->dev = &spi->dev;
	nor->mtd = &flash->mtd;
	nor->priv = flash;

	spi_set_drvdata(spi, flash);
	flash->mtd.priv = nor;
	flash->spi = spi;

	if (spi->mode & SPI_RX_QUAD)
	mode = SPI_NOR_QUAD;
	else if (spi->mode & SPI_RX_DUAL)
	mode = SPI_NOR_DUAL;

	if (data && data->name)
	flash->mtd.name = data->name;

	/* For some (historical?) reason many platforms provide two different
	* names in flash_platform_data: "name" and "type". Quite often name is
	* set to "m25p80" and then "type" provides a real chip name.
	* If that's the case, respect "type" and ignore a "name".
	*/
	if (data && data->type)
	id = spi_nor_match_id(data->type);

	/* If we didn't get name from platform, simply use "modalias". */
	if (!id)
	id = spi_get_device_id(spi);

	ret = spi_nor_scan(nor, id, mode);
	if (ret)
	return ret;

	ppdata.of_node = spi->dev.of_node;

	return mtd_device_parse_register(&flash->mtd, NULL, &ppdata,
	data ? data->parts : NULL,
	data ? data->nr_parts : 0);
	}


	static int m25p_remove(struct spi_device *spi)
	{
	struct m25p *flash = spi_get_drvdata(spi);

	/* Clean up MTD stuff. */
	return mtd_device_unregister(&flash->mtd);
	}


	static struct spi_driver m25p80_driver = {
	.driver = {
	.name = "m25p80",
	.owner = THIS_MODULE,
	},
	.id_table = spi_nor_ids,
	.probe = m25p_probe,
	.remove = m25p_remove,

	/* REVISIT: many of these chips have deep power-down modes, which
	* should clearly be entered on suspend() to minimize power use.
	* And also when they're otherwise idle...
	*/
	};

	module_spi_driver(m25p80_driver);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Mike Lavender");
	MODULE_DESCRIPTION("MTD SPI driver for ST M25Pxx flash chips");