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15#include <linux/kernel.h>
16#include <linux/err.h>
17#include <linux/slab.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20#include <linux/gpio/consumer.h>
21#include <linux/io.h>
22#include <linux/mtd/mtd.h>
23#include <linux/mtd/rawnand.h>
24#include <linux/mtd/partitions.h>
25#include <linux/mtd/nand-gpio.h>
26#include <linux/of.h>
27#include <linux/of_address.h>
28
29struct gpiomtd {
30 void __iomem *io_sync;
31 struct nand_chip nand_chip;
32 struct gpio_nand_platdata plat;
33 struct gpio_desc *nce;
34 struct gpio_desc *cle;
35 struct gpio_desc *ale;
36 struct gpio_desc *rdy;
37 struct gpio_desc *nwp;
38};
39
40static inline struct gpiomtd *gpio_nand_getpriv(struct mtd_info *mtd)
41{
42 return container_of(mtd_to_nand(mtd), struct gpiomtd, nand_chip);
43}
44
45
46#ifdef CONFIG_ARM
47
48
49
50
51
52
53
54static void gpio_nand_dosync(struct gpiomtd *gpiomtd)
55{
56 unsigned long tmp;
57
58 if (gpiomtd->io_sync) {
59
60
61
62
63
64 tmp = readl(gpiomtd->io_sync);
65 asm volatile("mov %1, %0\n" : "=r" (tmp) : "r" (tmp));
66 }
67}
68#else
69static inline void gpio_nand_dosync(struct gpiomtd *gpiomtd) {}
70#endif
71
72static void gpio_nand_cmd_ctrl(struct nand_chip *chip, int cmd,
73 unsigned int ctrl)
74{
75 struct gpiomtd *gpiomtd = gpio_nand_getpriv(nand_to_mtd(chip));
76
77 gpio_nand_dosync(gpiomtd);
78
79 if (ctrl & NAND_CTRL_CHANGE) {
80 if (gpiomtd->nce)
81 gpiod_set_value(gpiomtd->nce, !(ctrl & NAND_NCE));
82 gpiod_set_value(gpiomtd->cle, !!(ctrl & NAND_CLE));
83 gpiod_set_value(gpiomtd->ale, !!(ctrl & NAND_ALE));
84 gpio_nand_dosync(gpiomtd);
85 }
86 if (cmd == NAND_CMD_NONE)
87 return;
88
89 writeb(cmd, gpiomtd->nand_chip.legacy.IO_ADDR_W);
90 gpio_nand_dosync(gpiomtd);
91}
92
93static int gpio_nand_devready(struct nand_chip *chip)
94{
95 struct gpiomtd *gpiomtd = gpio_nand_getpriv(nand_to_mtd(chip));
96
97 return gpiod_get_value(gpiomtd->rdy);
98}
99
100#ifdef CONFIG_OF
101static const struct of_device_id gpio_nand_id_table[] = {
102 { .compatible = "gpio-control-nand" },
103 {}
104};
105MODULE_DEVICE_TABLE(of, gpio_nand_id_table);
106
107static int gpio_nand_get_config_of(const struct device *dev,
108 struct gpio_nand_platdata *plat)
109{
110 u32 val;
111
112 if (!dev->of_node)
113 return -ENODEV;
114
115 if (!of_property_read_u32(dev->of_node, "bank-width", &val)) {
116 if (val == 2) {
117 plat->options |= NAND_BUSWIDTH_16;
118 } else if (val != 1) {
119 dev_err(dev, "invalid bank-width %u\n", val);
120 return -EINVAL;
121 }
122 }
123
124 if (!of_property_read_u32(dev->of_node, "chip-delay", &val))
125 plat->chip_delay = val;
126
127 return 0;
128}
129
130static struct resource *gpio_nand_get_io_sync_of(struct platform_device *pdev)
131{
132 struct resource *r;
133 u64 addr;
134
135 if (of_property_read_u64(pdev->dev.of_node,
136 "gpio-control-nand,io-sync-reg", &addr))
137 return NULL;
138
139 r = devm_kzalloc(&pdev->dev, sizeof(*r), GFP_KERNEL);
140 if (!r)
141 return NULL;
142
143 r->start = addr;
144 r->end = r->start + 0x3;
145 r->flags = IORESOURCE_MEM;
146
147 return r;
148}
149#else
150static inline int gpio_nand_get_config_of(const struct device *dev,
151 struct gpio_nand_platdata *plat)
152{
153 return -ENOSYS;
154}
155
156static inline struct resource *
157gpio_nand_get_io_sync_of(struct platform_device *pdev)
158{
159 return NULL;
160}
161#endif
162
163static inline int gpio_nand_get_config(const struct device *dev,
164 struct gpio_nand_platdata *plat)
165{
166 int ret = gpio_nand_get_config_of(dev, plat);
167
168 if (!ret)
169 return ret;
170
171 if (dev_get_platdata(dev)) {
172 memcpy(plat, dev_get_platdata(dev), sizeof(*plat));
173 return 0;
174 }
175
176 return -EINVAL;
177}
178
179static inline struct resource *
180gpio_nand_get_io_sync(struct platform_device *pdev)
181{
182 struct resource *r = gpio_nand_get_io_sync_of(pdev);
183
184 if (r)
185 return r;
186
187 return platform_get_resource(pdev, IORESOURCE_MEM, 1);
188}
189
190static int gpio_nand_remove(struct platform_device *pdev)
191{
192 struct gpiomtd *gpiomtd = platform_get_drvdata(pdev);
193
194 nand_release(&gpiomtd->nand_chip);
195
196
197 if (gpiomtd->nwp && !IS_ERR(gpiomtd->nwp))
198 gpiod_set_value(gpiomtd->nwp, 0);
199 if (gpiomtd->nce && !IS_ERR(gpiomtd->nce))
200 gpiod_set_value(gpiomtd->nce, 0);
201
202 return 0;
203}
204
205static int gpio_nand_probe(struct platform_device *pdev)
206{
207 struct gpiomtd *gpiomtd;
208 struct nand_chip *chip;
209 struct mtd_info *mtd;
210 struct resource *res;
211 struct device *dev = &pdev->dev;
212 int ret = 0;
213
214 if (!dev->of_node && !dev_get_platdata(dev))
215 return -EINVAL;
216
217 gpiomtd = devm_kzalloc(dev, sizeof(*gpiomtd), GFP_KERNEL);
218 if (!gpiomtd)
219 return -ENOMEM;
220
221 chip = &gpiomtd->nand_chip;
222
223 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
224 chip->legacy.IO_ADDR_R = devm_ioremap_resource(dev, res);
225 if (IS_ERR(chip->legacy.IO_ADDR_R))
226 return PTR_ERR(chip->legacy.IO_ADDR_R);
227
228 res = gpio_nand_get_io_sync(pdev);
229 if (res) {
230 gpiomtd->io_sync = devm_ioremap_resource(dev, res);
231 if (IS_ERR(gpiomtd->io_sync))
232 return PTR_ERR(gpiomtd->io_sync);
233 }
234
235 ret = gpio_nand_get_config(dev, &gpiomtd->plat);
236 if (ret)
237 return ret;
238
239
240 gpiomtd->nce = devm_gpiod_get_optional(dev, "nce", GPIOD_OUT_HIGH);
241 if (IS_ERR(gpiomtd->nce))
242 return PTR_ERR(gpiomtd->nce);
243
244
245 gpiomtd->nwp = devm_gpiod_get_optional(dev, "nwp", GPIOD_OUT_LOW);
246 if (IS_ERR(gpiomtd->nwp)) {
247 ret = PTR_ERR(gpiomtd->nwp);
248 goto out_ce;
249 }
250
251 gpiomtd->ale = devm_gpiod_get(dev, "ale", GPIOD_OUT_LOW);
252 if (IS_ERR(gpiomtd->ale)) {
253 ret = PTR_ERR(gpiomtd->ale);
254 goto out_ce;
255 }
256
257 gpiomtd->cle = devm_gpiod_get(dev, "cle", GPIOD_OUT_LOW);
258 if (IS_ERR(gpiomtd->cle)) {
259 ret = PTR_ERR(gpiomtd->cle);
260 goto out_ce;
261 }
262
263 gpiomtd->rdy = devm_gpiod_get_optional(dev, "rdy", GPIOD_IN);
264 if (IS_ERR(gpiomtd->rdy)) {
265 ret = PTR_ERR(gpiomtd->rdy);
266 goto out_ce;
267 }
268
269 if (gpiomtd->rdy)
270 chip->legacy.dev_ready = gpio_nand_devready;
271
272 nand_set_flash_node(chip, pdev->dev.of_node);
273 chip->legacy.IO_ADDR_W = chip->legacy.IO_ADDR_R;
274 chip->ecc.mode = NAND_ECC_SOFT;
275 chip->ecc.algo = NAND_ECC_HAMMING;
276 chip->options = gpiomtd->plat.options;
277 chip->legacy.chip_delay = gpiomtd->plat.chip_delay;
278 chip->legacy.cmd_ctrl = gpio_nand_cmd_ctrl;
279
280 mtd = nand_to_mtd(chip);
281 mtd->dev.parent = dev;
282
283 platform_set_drvdata(pdev, gpiomtd);
284
285
286 if (gpiomtd->nwp && !IS_ERR(gpiomtd->nwp))
287 gpiod_direction_output(gpiomtd->nwp, 1);
288
289 ret = nand_scan(chip, 1);
290 if (ret)
291 goto err_wp;
292
293 if (gpiomtd->plat.adjust_parts)
294 gpiomtd->plat.adjust_parts(&gpiomtd->plat, mtd->size);
295
296 ret = mtd_device_register(mtd, gpiomtd->plat.parts,
297 gpiomtd->plat.num_parts);
298 if (!ret)
299 return 0;
300
301err_wp:
302 if (gpiomtd->nwp && !IS_ERR(gpiomtd->nwp))
303 gpiod_set_value(gpiomtd->nwp, 0);
304out_ce:
305 if (gpiomtd->nce && !IS_ERR(gpiomtd->nce))
306 gpiod_set_value(gpiomtd->nce, 0);
307
308 return ret;
309}
310
311static struct platform_driver gpio_nand_driver = {
312 .probe = gpio_nand_probe,
313 .remove = gpio_nand_remove,
314 .driver = {
315 .name = "gpio-nand",
316 .of_match_table = of_match_ptr(gpio_nand_id_table),
317 },
318};
319
320module_platform_driver(gpio_nand_driver);
321
322MODULE_LICENSE("GPL");
323MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
324MODULE_DESCRIPTION("GPIO NAND Driver");
325