1 /*
2  * Freescale UPM NAND driver.
3  *
4  * Copyright © 2007-2008  MontaVista Software, Inc.
5  *
6  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/delay.h>
17 #include <linux/mtd/nand.h>
18 #include <linux/mtd/nand_ecc.h>
19 #include <linux/mtd/partitions.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/of_platform.h>
22 #include <linux/of_gpio.h>
23 #include <linux/io.h>
24 #include <linux/slab.h>
25 #include <asm/fsl_lbc.h>
26 
27 #define FSL_UPM_WAIT_RUN_PATTERN  0x1
28 #define FSL_UPM_WAIT_WRITE_BYTE   0x2
29 #define FSL_UPM_WAIT_WRITE_BUFFER 0x4
30 
31 struct fsl_upm_nand {
32 	struct device *dev;
33 	struct mtd_info mtd;
34 	struct nand_chip chip;
35 	int last_ctrl;
36 	struct mtd_partition *parts;
37 	struct fsl_upm upm;
38 	uint8_t upm_addr_offset;
39 	uint8_t upm_cmd_offset;
40 	void __iomem *io_base;
41 	int rnb_gpio[NAND_MAX_CHIPS];
42 	uint32_t mchip_offsets[NAND_MAX_CHIPS];
43 	uint32_t mchip_count;
44 	uint32_t mchip_number;
45 	int chip_delay;
46 	uint32_t wait_flags;
47 };
48 
to_fsl_upm_nand(struct mtd_info * mtdinfo)49 static inline struct fsl_upm_nand *to_fsl_upm_nand(struct mtd_info *mtdinfo)
50 {
51 	return container_of(mtdinfo, struct fsl_upm_nand, mtd);
52 }
53 
fun_chip_ready(struct mtd_info * mtd)54 static int fun_chip_ready(struct mtd_info *mtd)
55 {
56 	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
57 
58 	if (gpio_get_value(fun->rnb_gpio[fun->mchip_number]))
59 		return 1;
60 
61 	dev_vdbg(fun->dev, "busy\n");
62 	return 0;
63 }
64 
fun_wait_rnb(struct fsl_upm_nand * fun)65 static void fun_wait_rnb(struct fsl_upm_nand *fun)
66 {
67 	if (fun->rnb_gpio[fun->mchip_number] >= 0) {
68 		int cnt = 1000000;
69 
70 		while (--cnt && !fun_chip_ready(&fun->mtd))
71 			cpu_relax();
72 		if (!cnt)
73 			dev_err(fun->dev, "tired waiting for RNB\n");
74 	} else {
75 		ndelay(100);
76 	}
77 }
78 
fun_cmd_ctrl(struct mtd_info * mtd,int cmd,unsigned int ctrl)79 static void fun_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
80 {
81 	struct nand_chip *chip = mtd->priv;
82 	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
83 	u32 mar;
84 
85 	if (!(ctrl & fun->last_ctrl)) {
86 		fsl_upm_end_pattern(&fun->upm);
87 
88 		if (cmd == NAND_CMD_NONE)
89 			return;
90 
91 		fun->last_ctrl = ctrl & (NAND_ALE | NAND_CLE);
92 	}
93 
94 	if (ctrl & NAND_CTRL_CHANGE) {
95 		if (ctrl & NAND_ALE)
96 			fsl_upm_start_pattern(&fun->upm, fun->upm_addr_offset);
97 		else if (ctrl & NAND_CLE)
98 			fsl_upm_start_pattern(&fun->upm, fun->upm_cmd_offset);
99 	}
100 
101 	mar = (cmd << (32 - fun->upm.width)) |
102 		fun->mchip_offsets[fun->mchip_number];
103 	fsl_upm_run_pattern(&fun->upm, chip->IO_ADDR_R, mar);
104 
105 	if (fun->wait_flags & FSL_UPM_WAIT_RUN_PATTERN)
106 		fun_wait_rnb(fun);
107 }
108 
fun_select_chip(struct mtd_info * mtd,int mchip_nr)109 static void fun_select_chip(struct mtd_info *mtd, int mchip_nr)
110 {
111 	struct nand_chip *chip = mtd->priv;
112 	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
113 
114 	if (mchip_nr == -1) {
115 		chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
116 	} else if (mchip_nr >= 0 && mchip_nr < NAND_MAX_CHIPS) {
117 		fun->mchip_number = mchip_nr;
118 		chip->IO_ADDR_R = fun->io_base + fun->mchip_offsets[mchip_nr];
119 		chip->IO_ADDR_W = chip->IO_ADDR_R;
120 	} else {
121 		BUG();
122 	}
123 }
124 
fun_read_byte(struct mtd_info * mtd)125 static uint8_t fun_read_byte(struct mtd_info *mtd)
126 {
127 	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
128 
129 	return in_8(fun->chip.IO_ADDR_R);
130 }
131 
fun_read_buf(struct mtd_info * mtd,uint8_t * buf,int len)132 static void fun_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
133 {
134 	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
135 	int i;
136 
137 	for (i = 0; i < len; i++)
138 		buf[i] = in_8(fun->chip.IO_ADDR_R);
139 }
140 
fun_write_buf(struct mtd_info * mtd,const uint8_t * buf,int len)141 static void fun_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
142 {
143 	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
144 	int i;
145 
146 	for (i = 0; i < len; i++) {
147 		out_8(fun->chip.IO_ADDR_W, buf[i]);
148 		if (fun->wait_flags & FSL_UPM_WAIT_WRITE_BYTE)
149 			fun_wait_rnb(fun);
150 	}
151 	if (fun->wait_flags & FSL_UPM_WAIT_WRITE_BUFFER)
152 		fun_wait_rnb(fun);
153 }
154 
fun_chip_init(struct fsl_upm_nand * fun,const struct device_node * upm_np,const struct resource * io_res)155 static int __devinit fun_chip_init(struct fsl_upm_nand *fun,
156 				   const struct device_node *upm_np,
157 				   const struct resource *io_res)
158 {
159 	int ret;
160 	struct device_node *flash_np;
161 	struct mtd_part_parser_data ppdata;
162 
163 	fun->chip.IO_ADDR_R = fun->io_base;
164 	fun->chip.IO_ADDR_W = fun->io_base;
165 	fun->chip.cmd_ctrl = fun_cmd_ctrl;
166 	fun->chip.chip_delay = fun->chip_delay;
167 	fun->chip.read_byte = fun_read_byte;
168 	fun->chip.read_buf = fun_read_buf;
169 	fun->chip.write_buf = fun_write_buf;
170 	fun->chip.ecc.mode = NAND_ECC_SOFT;
171 	if (fun->mchip_count > 1)
172 		fun->chip.select_chip = fun_select_chip;
173 
174 	if (fun->rnb_gpio[0] >= 0)
175 		fun->chip.dev_ready = fun_chip_ready;
176 
177 	fun->mtd.priv = &fun->chip;
178 	fun->mtd.owner = THIS_MODULE;
179 
180 	flash_np = of_get_next_child(upm_np, NULL);
181 	if (!flash_np)
182 		return -ENODEV;
183 
184 	fun->mtd.name = kasprintf(GFP_KERNEL, "0x%llx.%s", (u64)io_res->start,
185 				  flash_np->name);
186 	if (!fun->mtd.name) {
187 		ret = -ENOMEM;
188 		goto err;
189 	}
190 
191 	ret = nand_scan(&fun->mtd, fun->mchip_count);
192 	if (ret)
193 		goto err;
194 
195 	ppdata.of_node = flash_np;
196 	ret = mtd_device_parse_register(&fun->mtd, NULL, &ppdata, NULL, 0);
197 err:
198 	of_node_put(flash_np);
199 	if (ret)
200 		kfree(fun->mtd.name);
201 	return ret;
202 }
203 
fun_probe(struct platform_device * ofdev)204 static int __devinit fun_probe(struct platform_device *ofdev)
205 {
206 	struct fsl_upm_nand *fun;
207 	struct resource io_res;
208 	const __be32 *prop;
209 	int rnb_gpio;
210 	int ret;
211 	int size;
212 	int i;
213 
214 	fun = kzalloc(sizeof(*fun), GFP_KERNEL);
215 	if (!fun)
216 		return -ENOMEM;
217 
218 	ret = of_address_to_resource(ofdev->dev.of_node, 0, &io_res);
219 	if (ret) {
220 		dev_err(&ofdev->dev, "can't get IO base\n");
221 		goto err1;
222 	}
223 
224 	ret = fsl_upm_find(io_res.start, &fun->upm);
225 	if (ret) {
226 		dev_err(&ofdev->dev, "can't find UPM\n");
227 		goto err1;
228 	}
229 
230 	prop = of_get_property(ofdev->dev.of_node, "fsl,upm-addr-offset",
231 			       &size);
232 	if (!prop || size != sizeof(uint32_t)) {
233 		dev_err(&ofdev->dev, "can't get UPM address offset\n");
234 		ret = -EINVAL;
235 		goto err1;
236 	}
237 	fun->upm_addr_offset = *prop;
238 
239 	prop = of_get_property(ofdev->dev.of_node, "fsl,upm-cmd-offset", &size);
240 	if (!prop || size != sizeof(uint32_t)) {
241 		dev_err(&ofdev->dev, "can't get UPM command offset\n");
242 		ret = -EINVAL;
243 		goto err1;
244 	}
245 	fun->upm_cmd_offset = *prop;
246 
247 	prop = of_get_property(ofdev->dev.of_node,
248 			       "fsl,upm-addr-line-cs-offsets", &size);
249 	if (prop && (size / sizeof(uint32_t)) > 0) {
250 		fun->mchip_count = size / sizeof(uint32_t);
251 		if (fun->mchip_count >= NAND_MAX_CHIPS) {
252 			dev_err(&ofdev->dev, "too much multiple chips\n");
253 			goto err1;
254 		}
255 		for (i = 0; i < fun->mchip_count; i++)
256 			fun->mchip_offsets[i] = be32_to_cpu(prop[i]);
257 	} else {
258 		fun->mchip_count = 1;
259 	}
260 
261 	for (i = 0; i < fun->mchip_count; i++) {
262 		fun->rnb_gpio[i] = -1;
263 		rnb_gpio = of_get_gpio(ofdev->dev.of_node, i);
264 		if (rnb_gpio >= 0) {
265 			ret = gpio_request(rnb_gpio, dev_name(&ofdev->dev));
266 			if (ret) {
267 				dev_err(&ofdev->dev,
268 					"can't request RNB gpio #%d\n", i);
269 				goto err2;
270 			}
271 			gpio_direction_input(rnb_gpio);
272 			fun->rnb_gpio[i] = rnb_gpio;
273 		} else if (rnb_gpio == -EINVAL) {
274 			dev_err(&ofdev->dev, "RNB gpio #%d is invalid\n", i);
275 			goto err2;
276 		}
277 	}
278 
279 	prop = of_get_property(ofdev->dev.of_node, "chip-delay", NULL);
280 	if (prop)
281 		fun->chip_delay = be32_to_cpup(prop);
282 	else
283 		fun->chip_delay = 50;
284 
285 	prop = of_get_property(ofdev->dev.of_node, "fsl,upm-wait-flags", &size);
286 	if (prop && size == sizeof(uint32_t))
287 		fun->wait_flags = be32_to_cpup(prop);
288 	else
289 		fun->wait_flags = FSL_UPM_WAIT_RUN_PATTERN |
290 				  FSL_UPM_WAIT_WRITE_BYTE;
291 
292 	fun->io_base = devm_ioremap_nocache(&ofdev->dev, io_res.start,
293 					    resource_size(&io_res));
294 	if (!fun->io_base) {
295 		ret = -ENOMEM;
296 		goto err2;
297 	}
298 
299 	fun->dev = &ofdev->dev;
300 	fun->last_ctrl = NAND_CLE;
301 
302 	ret = fun_chip_init(fun, ofdev->dev.of_node, &io_res);
303 	if (ret)
304 		goto err2;
305 
306 	dev_set_drvdata(&ofdev->dev, fun);
307 
308 	return 0;
309 err2:
310 	for (i = 0; i < fun->mchip_count; i++) {
311 		if (fun->rnb_gpio[i] < 0)
312 			break;
313 		gpio_free(fun->rnb_gpio[i]);
314 	}
315 err1:
316 	kfree(fun);
317 
318 	return ret;
319 }
320 
fun_remove(struct platform_device * ofdev)321 static int __devexit fun_remove(struct platform_device *ofdev)
322 {
323 	struct fsl_upm_nand *fun = dev_get_drvdata(&ofdev->dev);
324 	int i;
325 
326 	nand_release(&fun->mtd);
327 	kfree(fun->mtd.name);
328 
329 	for (i = 0; i < fun->mchip_count; i++) {
330 		if (fun->rnb_gpio[i] < 0)
331 			break;
332 		gpio_free(fun->rnb_gpio[i]);
333 	}
334 
335 	kfree(fun);
336 
337 	return 0;
338 }
339 
340 static const struct of_device_id of_fun_match[] = {
341 	{ .compatible = "fsl,upm-nand" },
342 	{},
343 };
344 MODULE_DEVICE_TABLE(of, of_fun_match);
345 
346 static struct platform_driver of_fun_driver = {
347 	.driver = {
348 		.name = "fsl,upm-nand",
349 		.owner = THIS_MODULE,
350 		.of_match_table = of_fun_match,
351 	},
352 	.probe		= fun_probe,
353 	.remove		= __devexit_p(fun_remove),
354 };
355 
356 module_platform_driver(of_fun_driver);
357 
358 MODULE_LICENSE("GPL");
359 MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
360 MODULE_DESCRIPTION("Driver for NAND chips working through Freescale "
361 		   "LocalBus User-Programmable Machine");
362