1/*
  2 *  linux/drivers/mtd/nand/cmx270-nand.c
  3 *
  4 *  Copyright (C) 2006 Compulab, Ltd.
  5 *  Mike Rapoport <mike@compulab.co.il>
  6 *
  7 *  Derived from drivers/mtd/nand/h1910.c
  8 *       Copyright (C) 2002 Marius Gröger (mag@sysgo.de)
  9 *       Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
 10 *
 11 *
 12 * This program is free software; you can redistribute it and/or modify
 13 * it under the terms of the GNU General Public License version 2 as
 14 * published by the Free Software Foundation.
 15 *
 16 *  Overview:
 17 *   This is a device driver for the NAND flash device found on the
 18 *   CM-X270 board.
 19 */
 20
 21#include <linux/mtd/nand.h>
 22#include <linux/mtd/partitions.h>
 23#include <linux/slab.h>
 24#include <linux/gpio.h>
 25#include <linux/module.h>
 26
 27#include <asm/io.h>
 28#include <asm/irq.h>
 29#include <asm/mach-types.h>
 30
 31#include <mach/pxa2xx-regs.h>
 32
 33#define GPIO_NAND_CS	(11)
 34#define GPIO_NAND_RB	(89)
 35
 36/* MTD structure for CM-X270 board */
 37static struct mtd_info *cmx270_nand_mtd;
 38
 39/* remaped IO address of the device */
 40static void __iomem *cmx270_nand_io;
 41
 42/*
 43 * Define static partitions for flash device
 44 */
 45static struct mtd_partition partition_info[] = {
 46	[0] = {
 47		.name	= "cmx270-0",
 48		.offset	= 0,
 49		.size	= MTDPART_SIZ_FULL
 50	}
 51};
 52#define NUM_PARTITIONS (ARRAY_SIZE(partition_info))
 53
 54static u_char cmx270_read_byte(struct mtd_info *mtd)
 55{
 56	struct nand_chip *this = mtd_to_nand(mtd);
 57
 58	return (readl(this->IO_ADDR_R) >> 16);
 59}
 60
 61static void cmx270_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
 62{
 63	int i;
 64	struct nand_chip *this = mtd_to_nand(mtd);
 65
 66	for (i=0; i<len; i++)
 67		writel((*buf++ << 16), this->IO_ADDR_W);
 68}
 69
 70static void cmx270_read_buf(struct mtd_info *mtd, u_char *buf, int len)
 71{
 72	int i;
 73	struct nand_chip *this = mtd_to_nand(mtd);
 74
 75	for (i=0; i<len; i++)
 76		*buf++ = readl(this->IO_ADDR_R) >> 16;
 77}
 78
 79static inline void nand_cs_on(void)
 80{
 81	gpio_set_value(GPIO_NAND_CS, 0);
 82}
 83
 84static void nand_cs_off(void)
 85{
 86	dsb();
 87
 88	gpio_set_value(GPIO_NAND_CS, 1);
 89}
 90
 91/*
 92 *	hardware specific access to control-lines
 93 */
 94static void cmx270_hwcontrol(struct mtd_info *mtd, int dat,
 95			     unsigned int ctrl)
 96{
 97	struct nand_chip *this = mtd_to_nand(mtd);
 98	unsigned int nandaddr = (unsigned int)this->IO_ADDR_W;
 99
100	dsb();
101
102	if (ctrl & NAND_CTRL_CHANGE) {
103		if ( ctrl & NAND_ALE )
104			nandaddr |=  (1 << 3);
105		else
106			nandaddr &= ~(1 << 3);
107		if ( ctrl & NAND_CLE )
108			nandaddr |=  (1 << 2);
109		else
110			nandaddr &= ~(1 << 2);
111		if ( ctrl & NAND_NCE )
112			nand_cs_on();
113		else
114			nand_cs_off();
115	}
116
117	dsb();
118	this->IO_ADDR_W = (void __iomem*)nandaddr;
119	if (dat != NAND_CMD_NONE)
120		writel((dat << 16), this->IO_ADDR_W);
121
122	dsb();
123}
124
125/*
126 *	read device ready pin
127 */
128static int cmx270_device_ready(struct mtd_info *mtd)
129{
130	dsb();
131
132	return (gpio_get_value(GPIO_NAND_RB));
133}
134
135/*
136 * Main initialization routine
137 */
138static int __init cmx270_init(void)
139{
140	struct nand_chip *this;
141	int ret;
142
143	if (!(machine_is_armcore() && cpu_is_pxa27x()))
144		return -ENODEV;
145
146	ret = gpio_request(GPIO_NAND_CS, "NAND CS");
147	if (ret) {
148		pr_warning("CM-X270: failed to request NAND CS gpio\n");
149		return ret;
150	}
151
152	gpio_direction_output(GPIO_NAND_CS, 1);
153
154	ret = gpio_request(GPIO_NAND_RB, "NAND R/B");
155	if (ret) {
156		pr_warning("CM-X270: failed to request NAND R/B gpio\n");
157		goto err_gpio_request;
158	}
159
160	gpio_direction_input(GPIO_NAND_RB);
161
162	/* Allocate memory for MTD device structure and private data */
163	this = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
164	if (!this) {
165		ret = -ENOMEM;
166		goto err_kzalloc;
167	}
168
169	cmx270_nand_io = ioremap(PXA_CS1_PHYS, 12);
170	if (!cmx270_nand_io) {
171		pr_debug("Unable to ioremap NAND device\n");
172		ret = -EINVAL;
173		goto err_ioremap;
174	}
175
176	cmx270_nand_mtd = nand_to_mtd(this);
177
178	/* Link the private data with the MTD structure */
179	cmx270_nand_mtd->owner = THIS_MODULE;
180
181	/* insert callbacks */
182	this->IO_ADDR_R = cmx270_nand_io;
183	this->IO_ADDR_W = cmx270_nand_io;
184	this->cmd_ctrl = cmx270_hwcontrol;
185	this->dev_ready = cmx270_device_ready;
186
187	/* 15 us command delay time */
188	this->chip_delay = 20;
189	this->ecc.mode = NAND_ECC_SOFT;
190	this->ecc.algo = NAND_ECC_HAMMING;
191
192	/* read/write functions */
193	this->read_byte = cmx270_read_byte;
194	this->read_buf = cmx270_read_buf;
195	this->write_buf = cmx270_write_buf;
196
197	/* Scan to find existence of the device */
198	ret = nand_scan(cmx270_nand_mtd, 1);
199	if (ret) {
200		pr_notice("No NAND device\n");
201		goto err_scan;
202	}
203
204	/* Register the partitions */
205	ret = mtd_device_parse_register(cmx270_nand_mtd, NULL, NULL,
206					partition_info, NUM_PARTITIONS);
207	if (ret)
208		goto err_scan;
209
210	/* Return happy */
211	return 0;
212
213err_scan:
214	iounmap(cmx270_nand_io);
215err_ioremap:
216	kfree(this);
217err_kzalloc:
218	gpio_free(GPIO_NAND_RB);
219err_gpio_request:
220	gpio_free(GPIO_NAND_CS);
221
222	return ret;
223
224}
225module_init(cmx270_init);
226
227/*
228 * Clean up routine
229 */
230static void __exit cmx270_cleanup(void)
231{
232	/* Release resources, unregister device */
233	nand_release(cmx270_nand_mtd);
234
235	gpio_free(GPIO_NAND_RB);
236	gpio_free(GPIO_NAND_CS);
237
238	iounmap(cmx270_nand_io);
239
240	kfree(mtd_to_nand(cmx270_nand_mtd));
241}
242module_exit(cmx270_cleanup);
243
244MODULE_LICENSE("GPL");
245MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
246MODULE_DESCRIPTION("NAND flash driver for Compulab CM-X270 Module");