xref: /openbmc/linux/drivers/mtd/nand/raw/ams-delta.c (revision a99237af)
1 /*
2  *  Copyright (C) 2006 Jonathan McDowell <noodles@earth.li>
3  *
4  *  Derived from drivers/mtd/nand/toto.c (removed in v2.6.28)
5  *    Copyright (c) 2003 Texas Instruments
6  *    Copyright (c) 2002 Thomas Gleixner <tgxl@linutronix.de>
7  *
8  *  Converted to platform driver by Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
9  *  Partially stolen from plat_nand.c
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  *
15  *  Overview:
16  *   This is a device driver for the NAND flash device found on the
17  *   Amstrad E3 (Delta).
18  */
19 
20 #include <linux/slab.h>
21 #include <linux/module.h>
22 #include <linux/delay.h>
23 #include <linux/mtd/mtd.h>
24 #include <linux/mtd/rawnand.h>
25 #include <linux/mtd/partitions.h>
26 #include <linux/gpio.h>
27 #include <linux/platform_data/gpio-omap.h>
28 
29 #include <asm/io.h>
30 #include <asm/sizes.h>
31 
32 #include <mach/board-ams-delta.h>
33 
34 #include <mach/hardware.h>
35 
36 /*
37  * MTD structure for E3 (Delta)
38  */
39 static struct mtd_info *ams_delta_mtd = NULL;
40 
41 /*
42  * Define partitions for flash devices
43  */
44 
45 static const struct mtd_partition partition_info[] = {
46 	{ .name		= "Kernel",
47 	  .offset	= 0,
48 	  .size		= 3 * SZ_1M + SZ_512K },
49 	{ .name		= "u-boot",
50 	  .offset	= 3 * SZ_1M + SZ_512K,
51 	  .size		= SZ_256K },
52 	{ .name		= "u-boot params",
53 	  .offset	= 3 * SZ_1M + SZ_512K + SZ_256K,
54 	  .size		= SZ_256K },
55 	{ .name		= "Amstrad LDR",
56 	  .offset	= 4 * SZ_1M,
57 	  .size		= SZ_256K },
58 	{ .name		= "File system",
59 	  .offset	= 4 * SZ_1M + 1 * SZ_256K,
60 	  .size		= 27 * SZ_1M },
61 	{ .name		= "PBL reserved",
62 	  .offset	= 32 * SZ_1M - 3 * SZ_256K,
63 	  .size		=  3 * SZ_256K },
64 };
65 
66 static void ams_delta_write_byte(struct mtd_info *mtd, u_char byte)
67 {
68 	struct nand_chip *this = mtd_to_nand(mtd);
69 	void __iomem *io_base = (void __iomem *)nand_get_controller_data(this);
70 
71 	writew(0, io_base + OMAP_MPUIO_IO_CNTL);
72 	writew(byte, this->IO_ADDR_W);
73 	gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NWE, 0);
74 	ndelay(40);
75 	gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NWE, 1);
76 }
77 
78 static u_char ams_delta_read_byte(struct mtd_info *mtd)
79 {
80 	u_char res;
81 	struct nand_chip *this = mtd_to_nand(mtd);
82 	void __iomem *io_base = (void __iomem *)nand_get_controller_data(this);
83 
84 	gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NRE, 0);
85 	ndelay(40);
86 	writew(~0, io_base + OMAP_MPUIO_IO_CNTL);
87 	res = readw(this->IO_ADDR_R);
88 	gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NRE, 1);
89 
90 	return res;
91 }
92 
93 static void ams_delta_write_buf(struct mtd_info *mtd, const u_char *buf,
94 				int len)
95 {
96 	int i;
97 
98 	for (i=0; i<len; i++)
99 		ams_delta_write_byte(mtd, buf[i]);
100 }
101 
102 static void ams_delta_read_buf(struct mtd_info *mtd, u_char *buf, int len)
103 {
104 	int i;
105 
106 	for (i=0; i<len; i++)
107 		buf[i] = ams_delta_read_byte(mtd);
108 }
109 
110 /*
111  * Command control function
112  *
113  * ctrl:
114  * NAND_NCE: bit 0 -> bit 2
115  * NAND_CLE: bit 1 -> bit 7
116  * NAND_ALE: bit 2 -> bit 6
117  */
118 static void ams_delta_hwcontrol(struct mtd_info *mtd, int cmd,
119 				unsigned int ctrl)
120 {
121 
122 	if (ctrl & NAND_CTRL_CHANGE) {
123 		gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NCE,
124 				(ctrl & NAND_NCE) == 0);
125 		gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_CLE,
126 				(ctrl & NAND_CLE) != 0);
127 		gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_ALE,
128 				(ctrl & NAND_ALE) != 0);
129 	}
130 
131 	if (cmd != NAND_CMD_NONE)
132 		ams_delta_write_byte(mtd, cmd);
133 }
134 
135 static int ams_delta_nand_ready(struct mtd_info *mtd)
136 {
137 	return gpio_get_value(AMS_DELTA_GPIO_PIN_NAND_RB);
138 }
139 
140 static const struct gpio _mandatory_gpio[] = {
141 	{
142 		.gpio	= AMS_DELTA_GPIO_PIN_NAND_NCE,
143 		.flags	= GPIOF_OUT_INIT_HIGH,
144 		.label	= "nand_nce",
145 	},
146 	{
147 		.gpio	= AMS_DELTA_GPIO_PIN_NAND_NRE,
148 		.flags	= GPIOF_OUT_INIT_HIGH,
149 		.label	= "nand_nre",
150 	},
151 	{
152 		.gpio	= AMS_DELTA_GPIO_PIN_NAND_NWP,
153 		.flags	= GPIOF_OUT_INIT_HIGH,
154 		.label	= "nand_nwp",
155 	},
156 	{
157 		.gpio	= AMS_DELTA_GPIO_PIN_NAND_NWE,
158 		.flags	= GPIOF_OUT_INIT_HIGH,
159 		.label	= "nand_nwe",
160 	},
161 	{
162 		.gpio	= AMS_DELTA_GPIO_PIN_NAND_ALE,
163 		.flags	= GPIOF_OUT_INIT_LOW,
164 		.label	= "nand_ale",
165 	},
166 	{
167 		.gpio	= AMS_DELTA_GPIO_PIN_NAND_CLE,
168 		.flags	= GPIOF_OUT_INIT_LOW,
169 		.label	= "nand_cle",
170 	},
171 };
172 
173 /*
174  * Main initialization routine
175  */
176 static int ams_delta_init(struct platform_device *pdev)
177 {
178 	struct nand_chip *this;
179 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
180 	void __iomem *io_base;
181 	int err = 0;
182 
183 	if (!res)
184 		return -ENXIO;
185 
186 	/* Allocate memory for MTD device structure and private data */
187 	this = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
188 	if (!this) {
189 		pr_warn("Unable to allocate E3 NAND MTD device structure.\n");
190 		err = -ENOMEM;
191 		goto out;
192 	}
193 
194 	ams_delta_mtd = nand_to_mtd(this);
195 	ams_delta_mtd->owner = THIS_MODULE;
196 
197 	/*
198 	 * Don't try to request the memory region from here,
199 	 * it should have been already requested from the
200 	 * gpio-omap driver and requesting it again would fail.
201 	 */
202 
203 	io_base = ioremap(res->start, resource_size(res));
204 	if (io_base == NULL) {
205 		dev_err(&pdev->dev, "ioremap failed\n");
206 		err = -EIO;
207 		goto out_free;
208 	}
209 
210 	nand_set_controller_data(this, (void *)io_base);
211 
212 	/* Set address of NAND IO lines */
213 	this->IO_ADDR_R = io_base + OMAP_MPUIO_INPUT_LATCH;
214 	this->IO_ADDR_W = io_base + OMAP_MPUIO_OUTPUT;
215 	this->read_byte = ams_delta_read_byte;
216 	this->write_buf = ams_delta_write_buf;
217 	this->read_buf = ams_delta_read_buf;
218 	this->cmd_ctrl = ams_delta_hwcontrol;
219 	if (gpio_request(AMS_DELTA_GPIO_PIN_NAND_RB, "nand_rdy") == 0) {
220 		this->dev_ready = ams_delta_nand_ready;
221 	} else {
222 		this->dev_ready = NULL;
223 		pr_notice("Couldn't request gpio for Delta NAND ready.\n");
224 	}
225 	/* 25 us command delay time */
226 	this->chip_delay = 30;
227 	this->ecc.mode = NAND_ECC_SOFT;
228 	this->ecc.algo = NAND_ECC_HAMMING;
229 
230 	platform_set_drvdata(pdev, io_base);
231 
232 	/* Set chip enabled, but  */
233 	err = gpio_request_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
234 	if (err)
235 		goto out_gpio;
236 
237 	/* Scan to find existence of the device */
238 	err = nand_scan(ams_delta_mtd, 1);
239 	if (err)
240 		goto out_mtd;
241 
242 	/* Register the partitions */
243 	mtd_device_register(ams_delta_mtd, partition_info,
244 			    ARRAY_SIZE(partition_info));
245 
246 	goto out;
247 
248  out_mtd:
249 	gpio_free_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
250 out_gpio:
251 	gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB);
252 	iounmap(io_base);
253 out_free:
254 	kfree(this);
255  out:
256 	return err;
257 }
258 
259 /*
260  * Clean up routine
261  */
262 static int ams_delta_cleanup(struct platform_device *pdev)
263 {
264 	void __iomem *io_base = platform_get_drvdata(pdev);
265 
266 	/* Release resources, unregister device */
267 	nand_release(ams_delta_mtd);
268 
269 	gpio_free_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
270 	gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB);
271 	iounmap(io_base);
272 
273 	/* Free the MTD device structure */
274 	kfree(mtd_to_nand(ams_delta_mtd));
275 
276 	return 0;
277 }
278 
279 static struct platform_driver ams_delta_nand_driver = {
280 	.probe		= ams_delta_init,
281 	.remove		= ams_delta_cleanup,
282 	.driver		= {
283 		.name	= "ams-delta-nand",
284 	},
285 };
286 
287 module_platform_driver(ams_delta_nand_driver);
288 
289 MODULE_LICENSE("GPL");
290 MODULE_AUTHOR("Jonathan McDowell <noodles@earth.li>");
291 MODULE_DESCRIPTION("Glue layer for NAND flash on Amstrad E3 (Delta)");
292