1 /*
2 * JZ4780 NAND driver
3 *
4 * Copyright (c) 2015 Imagination Technologies
5 * Author: Alex Smith <alex.smith@imgtec.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published
9 * by the Free Software Foundation.
10 */
11
12 #include <linux/delay.h>
13 #include <linux/init.h>
14 #include <linux/io.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/gpio/consumer.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 #include <linux/mtd/mtd.h>
23 #include <linux/mtd/nand.h>
24 #include <linux/mtd/partitions.h>
25
26 #include <linux/jz4780-nemc.h>
27
28 #include "jz4780_bch.h"
29
30 #define DRV_NAME "jz4780-nand"
31
32 #define OFFSET_DATA 0x00000000
33 #define OFFSET_CMD 0x00400000
34 #define OFFSET_ADDR 0x00800000
35
36 /* Command delay when there is no R/B pin. */
37 #define RB_DELAY_US 100
38
39 struct jz4780_nand_cs {
40 unsigned int bank;
41 void __iomem *base;
42 };
43
44 struct jz4780_nand_controller {
45 struct device *dev;
46 struct jz4780_bch *bch;
47 struct nand_hw_control controller;
48 unsigned int num_banks;
49 struct list_head chips;
50 int selected;
51 struct jz4780_nand_cs cs[];
52 };
53
54 struct jz4780_nand_chip {
55 struct nand_chip chip;
56 struct list_head chip_list;
57
58 struct gpio_desc *busy_gpio;
59 struct gpio_desc *wp_gpio;
60 unsigned int reading: 1;
61 };
62
to_jz4780_nand_chip(struct mtd_info * mtd)63 static inline struct jz4780_nand_chip *to_jz4780_nand_chip(struct mtd_info *mtd)
64 {
65 return container_of(mtd_to_nand(mtd), struct jz4780_nand_chip, chip);
66 }
67
to_jz4780_nand_controller(struct nand_hw_control * ctrl)68 static inline struct jz4780_nand_controller *to_jz4780_nand_controller(struct nand_hw_control *ctrl)
69 {
70 return container_of(ctrl, struct jz4780_nand_controller, controller);
71 }
72
jz4780_nand_select_chip(struct mtd_info * mtd,int chipnr)73 static void jz4780_nand_select_chip(struct mtd_info *mtd, int chipnr)
74 {
75 struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
76 struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
77 struct jz4780_nand_cs *cs;
78
79 /* Ensure the currently selected chip is deasserted. */
80 if (chipnr == -1 && nfc->selected >= 0) {
81 cs = &nfc->cs[nfc->selected];
82 jz4780_nemc_assert(nfc->dev, cs->bank, false);
83 }
84
85 nfc->selected = chipnr;
86 }
87
jz4780_nand_cmd_ctrl(struct mtd_info * mtd,int cmd,unsigned int ctrl)88 static void jz4780_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
89 unsigned int ctrl)
90 {
91 struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
92 struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
93 struct jz4780_nand_cs *cs;
94
95 if (WARN_ON(nfc->selected < 0))
96 return;
97
98 cs = &nfc->cs[nfc->selected];
99
100 jz4780_nemc_assert(nfc->dev, cs->bank, ctrl & NAND_NCE);
101
102 if (cmd == NAND_CMD_NONE)
103 return;
104
105 if (ctrl & NAND_ALE)
106 writeb(cmd, cs->base + OFFSET_ADDR);
107 else if (ctrl & NAND_CLE)
108 writeb(cmd, cs->base + OFFSET_CMD);
109 }
110
jz4780_nand_dev_ready(struct mtd_info * mtd)111 static int jz4780_nand_dev_ready(struct mtd_info *mtd)
112 {
113 struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
114
115 return !gpiod_get_value_cansleep(nand->busy_gpio);
116 }
117
jz4780_nand_ecc_hwctl(struct mtd_info * mtd,int mode)118 static void jz4780_nand_ecc_hwctl(struct mtd_info *mtd, int mode)
119 {
120 struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
121
122 nand->reading = (mode == NAND_ECC_READ);
123 }
124
jz4780_nand_ecc_calculate(struct mtd_info * mtd,const u8 * dat,u8 * ecc_code)125 static int jz4780_nand_ecc_calculate(struct mtd_info *mtd, const u8 *dat,
126 u8 *ecc_code)
127 {
128 struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
129 struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
130 struct jz4780_bch_params params;
131
132 /*
133 * Don't need to generate the ECC when reading, BCH does it for us as
134 * part of decoding/correction.
135 */
136 if (nand->reading)
137 return 0;
138
139 params.size = nand->chip.ecc.size;
140 params.bytes = nand->chip.ecc.bytes;
141 params.strength = nand->chip.ecc.strength;
142
143 return jz4780_bch_calculate(nfc->bch, ¶ms, dat, ecc_code);
144 }
145
jz4780_nand_ecc_correct(struct mtd_info * mtd,u8 * dat,u8 * read_ecc,u8 * calc_ecc)146 static int jz4780_nand_ecc_correct(struct mtd_info *mtd, u8 *dat,
147 u8 *read_ecc, u8 *calc_ecc)
148 {
149 struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
150 struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
151 struct jz4780_bch_params params;
152
153 params.size = nand->chip.ecc.size;
154 params.bytes = nand->chip.ecc.bytes;
155 params.strength = nand->chip.ecc.strength;
156
157 return jz4780_bch_correct(nfc->bch, ¶ms, dat, read_ecc);
158 }
159
jz4780_nand_init_ecc(struct jz4780_nand_chip * nand,struct device * dev)160 static int jz4780_nand_init_ecc(struct jz4780_nand_chip *nand, struct device *dev)
161 {
162 struct nand_chip *chip = &nand->chip;
163 struct mtd_info *mtd = nand_to_mtd(chip);
164 struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(chip->controller);
165 int eccbytes;
166
167 chip->ecc.bytes = fls((1 + 8) * chip->ecc.size) *
168 (chip->ecc.strength / 8);
169
170 switch (chip->ecc.mode) {
171 case NAND_ECC_HW:
172 if (!nfc->bch) {
173 dev_err(dev, "HW BCH selected, but BCH controller not found\n");
174 return -ENODEV;
175 }
176
177 chip->ecc.hwctl = jz4780_nand_ecc_hwctl;
178 chip->ecc.calculate = jz4780_nand_ecc_calculate;
179 chip->ecc.correct = jz4780_nand_ecc_correct;
180 /* fall through */
181 case NAND_ECC_SOFT:
182 dev_info(dev, "using %s (strength %d, size %d, bytes %d)\n",
183 (nfc->bch) ? "hardware BCH" : "software ECC",
184 chip->ecc.strength, chip->ecc.size, chip->ecc.bytes);
185 break;
186 case NAND_ECC_NONE:
187 dev_info(dev, "not using ECC\n");
188 break;
189 default:
190 dev_err(dev, "ECC mode %d not supported\n", chip->ecc.mode);
191 return -EINVAL;
192 }
193
194 /* The NAND core will generate the ECC layout for SW ECC */
195 if (chip->ecc.mode != NAND_ECC_HW)
196 return 0;
197
198 /* Generate ECC layout. ECC codes are right aligned in the OOB area. */
199 eccbytes = mtd->writesize / chip->ecc.size * chip->ecc.bytes;
200
201 if (eccbytes > mtd->oobsize - 2) {
202 dev_err(dev,
203 "invalid ECC config: required %d ECC bytes, but only %d are available",
204 eccbytes, mtd->oobsize - 2);
205 return -EINVAL;
206 }
207
208 mtd->ooblayout = &nand_ooblayout_lp_ops;
209
210 return 0;
211 }
212
jz4780_nand_init_chip(struct platform_device * pdev,struct jz4780_nand_controller * nfc,struct device_node * np,unsigned int chipnr)213 static int jz4780_nand_init_chip(struct platform_device *pdev,
214 struct jz4780_nand_controller *nfc,
215 struct device_node *np,
216 unsigned int chipnr)
217 {
218 struct device *dev = &pdev->dev;
219 struct jz4780_nand_chip *nand;
220 struct jz4780_nand_cs *cs;
221 struct resource *res;
222 struct nand_chip *chip;
223 struct mtd_info *mtd;
224 const __be32 *reg;
225 int ret = 0;
226
227 cs = &nfc->cs[chipnr];
228
229 reg = of_get_property(np, "reg", NULL);
230 if (!reg)
231 return -EINVAL;
232
233 cs->bank = be32_to_cpu(*reg);
234
235 jz4780_nemc_set_type(nfc->dev, cs->bank, JZ4780_NEMC_BANK_NAND);
236
237 res = platform_get_resource(pdev, IORESOURCE_MEM, chipnr);
238 cs->base = devm_ioremap_resource(dev, res);
239 if (IS_ERR(cs->base))
240 return PTR_ERR(cs->base);
241
242 nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
243 if (!nand)
244 return -ENOMEM;
245
246 nand->busy_gpio = devm_gpiod_get_optional(dev, "rb", GPIOD_IN);
247
248 if (IS_ERR(nand->busy_gpio)) {
249 ret = PTR_ERR(nand->busy_gpio);
250 dev_err(dev, "failed to request busy GPIO: %d\n", ret);
251 return ret;
252 } else if (nand->busy_gpio) {
253 nand->chip.dev_ready = jz4780_nand_dev_ready;
254 }
255
256 nand->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_LOW);
257
258 if (IS_ERR(nand->wp_gpio)) {
259 ret = PTR_ERR(nand->wp_gpio);
260 dev_err(dev, "failed to request WP GPIO: %d\n", ret);
261 return ret;
262 }
263
264 chip = &nand->chip;
265 mtd = nand_to_mtd(chip);
266 mtd->name = devm_kasprintf(dev, GFP_KERNEL, "%s.%d", dev_name(dev),
267 cs->bank);
268 if (!mtd->name)
269 return -ENOMEM;
270 mtd->dev.parent = dev;
271
272 chip->IO_ADDR_R = cs->base + OFFSET_DATA;
273 chip->IO_ADDR_W = cs->base + OFFSET_DATA;
274 chip->chip_delay = RB_DELAY_US;
275 chip->options = NAND_NO_SUBPAGE_WRITE;
276 chip->select_chip = jz4780_nand_select_chip;
277 chip->cmd_ctrl = jz4780_nand_cmd_ctrl;
278 chip->ecc.mode = NAND_ECC_HW;
279 chip->controller = &nfc->controller;
280 nand_set_flash_node(chip, np);
281
282 ret = nand_scan_ident(mtd, 1, NULL);
283 if (ret)
284 return ret;
285
286 ret = jz4780_nand_init_ecc(nand, dev);
287 if (ret)
288 return ret;
289
290 ret = nand_scan_tail(mtd);
291 if (ret)
292 return ret;
293
294 ret = mtd_device_register(mtd, NULL, 0);
295 if (ret) {
296 nand_release(mtd);
297 return ret;
298 }
299
300 list_add_tail(&nand->chip_list, &nfc->chips);
301
302 return 0;
303 }
304
jz4780_nand_cleanup_chips(struct jz4780_nand_controller * nfc)305 static void jz4780_nand_cleanup_chips(struct jz4780_nand_controller *nfc)
306 {
307 struct jz4780_nand_chip *chip;
308
309 while (!list_empty(&nfc->chips)) {
310 chip = list_first_entry(&nfc->chips, struct jz4780_nand_chip, chip_list);
311 nand_release(nand_to_mtd(&chip->chip));
312 list_del(&chip->chip_list);
313 }
314 }
315
jz4780_nand_init_chips(struct jz4780_nand_controller * nfc,struct platform_device * pdev)316 static int jz4780_nand_init_chips(struct jz4780_nand_controller *nfc,
317 struct platform_device *pdev)
318 {
319 struct device *dev = &pdev->dev;
320 struct device_node *np;
321 int i = 0;
322 int ret;
323 int num_chips = of_get_child_count(dev->of_node);
324
325 if (num_chips > nfc->num_banks) {
326 dev_err(dev, "found %d chips but only %d banks\n", num_chips, nfc->num_banks);
327 return -EINVAL;
328 }
329
330 for_each_child_of_node(dev->of_node, np) {
331 ret = jz4780_nand_init_chip(pdev, nfc, np, i);
332 if (ret) {
333 jz4780_nand_cleanup_chips(nfc);
334 return ret;
335 }
336
337 i++;
338 }
339
340 return 0;
341 }
342
jz4780_nand_probe(struct platform_device * pdev)343 static int jz4780_nand_probe(struct platform_device *pdev)
344 {
345 struct device *dev = &pdev->dev;
346 unsigned int num_banks;
347 struct jz4780_nand_controller *nfc;
348 int ret;
349
350 num_banks = jz4780_nemc_num_banks(dev);
351 if (num_banks == 0) {
352 dev_err(dev, "no banks found\n");
353 return -ENODEV;
354 }
355
356 nfc = devm_kzalloc(dev, sizeof(*nfc) + (sizeof(nfc->cs[0]) * num_banks), GFP_KERNEL);
357 if (!nfc)
358 return -ENOMEM;
359
360 /*
361 * Check for BCH HW before we call nand_scan_ident, to prevent us from
362 * having to call it again if the BCH driver returns -EPROBE_DEFER.
363 */
364 nfc->bch = of_jz4780_bch_get(dev->of_node);
365 if (IS_ERR(nfc->bch))
366 return PTR_ERR(nfc->bch);
367
368 nfc->dev = dev;
369 nfc->num_banks = num_banks;
370
371 nand_hw_control_init(&nfc->controller);
372 INIT_LIST_HEAD(&nfc->chips);
373
374 ret = jz4780_nand_init_chips(nfc, pdev);
375 if (ret) {
376 if (nfc->bch)
377 jz4780_bch_release(nfc->bch);
378 return ret;
379 }
380
381 platform_set_drvdata(pdev, nfc);
382 return 0;
383 }
384
jz4780_nand_remove(struct platform_device * pdev)385 static int jz4780_nand_remove(struct platform_device *pdev)
386 {
387 struct jz4780_nand_controller *nfc = platform_get_drvdata(pdev);
388
389 if (nfc->bch)
390 jz4780_bch_release(nfc->bch);
391
392 jz4780_nand_cleanup_chips(nfc);
393
394 return 0;
395 }
396
397 static const struct of_device_id jz4780_nand_dt_match[] = {
398 { .compatible = "ingenic,jz4780-nand" },
399 {},
400 };
401 MODULE_DEVICE_TABLE(of, jz4780_nand_dt_match);
402
403 static struct platform_driver jz4780_nand_driver = {
404 .probe = jz4780_nand_probe,
405 .remove = jz4780_nand_remove,
406 .driver = {
407 .name = DRV_NAME,
408 .of_match_table = of_match_ptr(jz4780_nand_dt_match),
409 },
410 };
411 module_platform_driver(jz4780_nand_driver);
412
413 MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
414 MODULE_AUTHOR("Harvey Hunt <harveyhuntnexus@gmail.com>");
415 MODULE_DESCRIPTION("Ingenic JZ4780 NAND driver");
416 MODULE_LICENSE("GPL v2");
417