drivers/mtd/nand/gpio.c

   1 /*
   2  * drivers/mtd/nand/gpio.c
   3  *
   4  * Updated, and converted to generic GPIO based driver by Russell King.
   5  *
   6  * Written by Ben Dooks <ben@simtec.co.uk>
   7  *   Based on 2.4 version by Mark Whittaker
   8  *
   9  * © 2004 Simtec Electronics
  10  *
  11  * Device driver for NAND connected via GPIO
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License version 2 as
  15  * published by the Free Software Foundation.
  16  *
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/init.h>
  21 #include <linux/slab.h>
  22 #include <linux/module.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/gpio.h>
  25 #include <linux/io.h>
  26 #include <linux/mtd/mtd.h>
  27 #include <linux/mtd/nand.h>
  28 #include <linux/mtd/partitions.h>
  29 #include <linux/mtd/nand-gpio.h>
  30
  31 struct gpiomtd {
  32         void __iomem            *io_sync;
  33         struct mtd_info         mtd_info;
  34         struct nand_chip        nand_chip;
  35         struct gpio_nand_platdata plat;
  36 };
  37
  38 #define gpio_nand_getpriv(x) container_of(x, struct gpiomtd, mtd_info)
  39
  40
  41 #ifdef CONFIG_ARM
  42 /* gpio_nand_dosync()
  43  *
  44  * Make sure the GPIO state changes occur in-order with writes to NAND
  45  * memory region.
  46  * Needed on PXA due to bus-reordering within the SoC itself (see section on
  47  * I/O ordering in PXA manual (section 2.3, p35)
  48  */
  49 static void gpio_nand_dosync(struct gpiomtd *gpiomtd)
  50 {
  51         unsigned long tmp;
  52
  53         if (gpiomtd->io_sync) {
  54                 /*
  55                  * Linux memory barriers don't cater for what's required here.
  56                  * What's required is what's here - a read from a separate
  57                  * region with a dependency on that read.
  58                  */
  59                 tmp = readl(gpiomtd->io_sync);
  60                 asm volatile("mov %1, %0\n" : "=r" (tmp) : "r" (tmp));
  61         }
  62 }
  63 #else
  64 static inline void gpio_nand_dosync(struct gpiomtd *gpiomtd) {}
  65 #endif
  66
  67 static void gpio_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
  68 {
  69         struct gpiomtd *gpiomtd = gpio_nand_getpriv(mtd);
  70
  71         gpio_nand_dosync(gpiomtd);
  72
  73         if (ctrl & NAND_CTRL_CHANGE) {
  74                 gpio_set_value(gpiomtd->plat.gpio_nce, !(ctrl & NAND_NCE));
  75                 gpio_set_value(gpiomtd->plat.gpio_cle, !!(ctrl & NAND_CLE));
  76                 gpio_set_value(gpiomtd->plat.gpio_ale, !!(ctrl & NAND_ALE));
  77                 gpio_nand_dosync(gpiomtd);
  78         }
  79         if (cmd == NAND_CMD_NONE)
  80                 return;
  81
  82         writeb(cmd, gpiomtd->nand_chip.IO_ADDR_W);
  83         gpio_nand_dosync(gpiomtd);
  84 }
  85
  86 static void gpio_nand_writebuf(struct mtd_info *mtd, const u_char *buf, int len)
  87 {
  88         struct nand_chip *this = mtd->priv;
  89
  90         writesb(this->IO_ADDR_W, buf, len);
  91 }
  92
  93 static void gpio_nand_readbuf(struct mtd_info *mtd, u_char *buf, int len)
  94 {
  95         struct nand_chip *this = mtd->priv;
  96
  97         readsb(this->IO_ADDR_R, buf, len);
  98 }
  99
 100 static int gpio_nand_verifybuf(struct mtd_info *mtd, const u_char *buf, int len)
 101 {
 102         struct nand_chip *this = mtd->priv;
 103         unsigned char read, *p = (unsigned char *) buf;
 104         int i, err = 0;
 105
 106         for (i = 0; i < len; i++) {
 107                 read = readb(this->IO_ADDR_R);
 108                 if (read != p[i]) {
 109                         pr_debug("%s: err at %d (read %04x vs %04x)\n",
 110                                __func__, i, read, p[i]);
 111                         err = -EFAULT;
 112                 }
 113         }
 114         return err;
 115 }
 116
 117 static void gpio_nand_writebuf16(struct mtd_info *mtd, const u_char *buf,
 118                                  int len)
 119 {
 120         struct nand_chip *this = mtd->priv;
 121
 122         if (IS_ALIGNED((unsigned long)buf, 2)) {
 123                 writesw(this->IO_ADDR_W, buf, len>>1);
 124         } else {
 125                 int i;
 126                 unsigned short *ptr = (unsigned short *)buf;
 127
 128                 for (i = 0; i < len; i += 2, ptr++)
 129                         writew(*ptr, this->IO_ADDR_W);
 130         }
 131 }
 132
 133 static void gpio_nand_readbuf16(struct mtd_info *mtd, u_char *buf, int len)
 134 {
 135         struct nand_chip *this = mtd->priv;
 136
 137         if (IS_ALIGNED((unsigned long)buf, 2)) {
 138                 readsw(this->IO_ADDR_R, buf, len>>1);
 139         } else {
 140                 int i;
 141                 unsigned short *ptr = (unsigned short *)buf;
 142
 143                 for (i = 0; i < len; i += 2, ptr++)
 144                         *ptr = readw(this->IO_ADDR_R);
 145         }
 146 }
 147
 148 static int gpio_nand_verifybuf16(struct mtd_info *mtd, const u_char *buf,
 149                                  int len)
 150 {
 151         struct nand_chip *this = mtd->priv;
 152         unsigned short read, *p = (unsigned short *) buf;
 153         int i, err = 0;
 154         len >>= 1;
 155
 156         for (i = 0; i < len; i++) {
 157                 read = readw(this->IO_ADDR_R);
 158                 if (read != p[i]) {
 159                         pr_debug("%s: err at %d (read %04x vs %04x)\n",
 160                                __func__, i, read, p[i]);
 161                         err = -EFAULT;
 162                 }
 163         }
 164         return err;
 165 }
 166
 167
 168 static int gpio_nand_devready(struct mtd_info *mtd)
 169 {
 170         struct gpiomtd *gpiomtd = gpio_nand_getpriv(mtd);
 171         return gpio_get_value(gpiomtd->plat.gpio_rdy);
 172 }
 173
 174 static int __devexit gpio_nand_remove(struct platform_device *dev)
 175 {
 176         struct gpiomtd *gpiomtd = platform_get_drvdata(dev);
 177         struct resource *res;
 178
 179         nand_release(&gpiomtd->mtd_info);
 180
 181         res = platform_get_resource(dev, IORESOURCE_MEM, 1);
 182         iounmap(gpiomtd->io_sync);
 183         if (res)
 184                 release_mem_region(res->start, resource_size(res));
 185
 186         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 187         iounmap(gpiomtd->nand_chip.IO_ADDR_R);
 188         release_mem_region(res->start, resource_size(res));
 189
 190         if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
 191                 gpio_set_value(gpiomtd->plat.gpio_nwp, 0);
 192         gpio_set_value(gpiomtd->plat.gpio_nce, 1);
 193
 194         gpio_free(gpiomtd->plat.gpio_cle);
 195         gpio_free(gpiomtd->plat.gpio_ale);
 196         gpio_free(gpiomtd->plat.gpio_nce);
 197         if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
 198                 gpio_free(gpiomtd->plat.gpio_nwp);
 199         gpio_free(gpiomtd->plat.gpio_rdy);
 200
 201         kfree(gpiomtd);
 202
 203         return 0;
 204 }
 205
 206 static void __iomem *request_and_remap(struct resource *res, size_t size,
 207                                         const char *name, int *err)
 208 {
 209         void __iomem *ptr;
 210
 211         if (!request_mem_region(res->start, resource_size(res), name)) {
 212                 *err = -EBUSY;
 213                 return NULL;
 214         }
 215
 216         ptr = ioremap(res->start, size);
 217         if (!ptr) {
 218                 release_mem_region(res->start, resource_size(res));
 219                 *err = -ENOMEM;
 220         }
 221         return ptr;
 222 }
 223
 224 static int __devinit gpio_nand_probe(struct platform_device *dev)
 225 {
 226         struct gpiomtd *gpiomtd;
 227         struct nand_chip *this;
 228         struct resource *res0, *res1;
 229         int ret;
 230
 231         if (!dev->dev.platform_data)
 232                 return -EINVAL;
 233
 234         res0 = platform_get_resource(dev, IORESOURCE_MEM, 0);
 235         if (!res0)
 236                 return -EINVAL;
 237
 238         gpiomtd = kzalloc(sizeof(*gpiomtd), GFP_KERNEL);
 239         if (gpiomtd == NULL) {
 240                 dev_err(&dev->dev, "failed to create NAND MTD\n");
 241                 return -ENOMEM;
 242         }
 243
 244         this = &gpiomtd->nand_chip;
 245         this->IO_ADDR_R = request_and_remap(res0, 2, "NAND", &ret);
 246         if (!this->IO_ADDR_R) {
 247                 dev_err(&dev->dev, "unable to map NAND\n");
 248                 goto err_map;
 249         }
 250
 251         res1 = platform_get_resource(dev, IORESOURCE_MEM, 1);
 252         if (res1) {
 253                 gpiomtd->io_sync = request_and_remap(res1, 4, "NAND sync", &ret);
 254                 if (!gpiomtd->io_sync) {
 255                         dev_err(&dev->dev, "unable to map sync NAND\n");
 256                         goto err_sync;
 257                 }
 258         }
 259
 260         memcpy(&gpiomtd->plat, dev->dev.platform_data, sizeof(gpiomtd->plat));
 261
 262         ret = gpio_request(gpiomtd->plat.gpio_nce, "NAND NCE");
 263         if (ret)
 264                 goto err_nce;
 265         gpio_direction_output(gpiomtd->plat.gpio_nce, 1);
 266         if (gpio_is_valid(gpiomtd->plat.gpio_nwp)) {
 267                 ret = gpio_request(gpiomtd->plat.gpio_nwp, "NAND NWP");
 268                 if (ret)
 269                         goto err_nwp;
 270                 gpio_direction_output(gpiomtd->plat.gpio_nwp, 1);
 271         }
 272         ret = gpio_request(gpiomtd->plat.gpio_ale, "NAND ALE");
 273         if (ret)
 274                 goto err_ale;
 275         gpio_direction_output(gpiomtd->plat.gpio_ale, 0);
 276         ret = gpio_request(gpiomtd->plat.gpio_cle, "NAND CLE");
 277         if (ret)
 278                 goto err_cle;
 279         gpio_direction_output(gpiomtd->plat.gpio_cle, 0);
 280         ret = gpio_request(gpiomtd->plat.gpio_rdy, "NAND RDY");
 281         if (ret)
 282                 goto err_rdy;
 283         gpio_direction_input(gpiomtd->plat.gpio_rdy);
 284
 285
 286         this->IO_ADDR_W  = this->IO_ADDR_R;
 287         this->ecc.mode   = NAND_ECC_SOFT;
 288         this->options    = gpiomtd->plat.options;
 289         this->chip_delay = gpiomtd->plat.chip_delay;
 290
 291         /* install our routines */
 292         this->cmd_ctrl   = gpio_nand_cmd_ctrl;
 293         this->dev_ready  = gpio_nand_devready;
 294
 295         if (this->options & NAND_BUSWIDTH_16) {
 296                 this->read_buf   = gpio_nand_readbuf16;
 297                 this->write_buf  = gpio_nand_writebuf16;
 298                 this->verify_buf = gpio_nand_verifybuf16;
 299         } else {
 300                 this->read_buf   = gpio_nand_readbuf;
 301                 this->write_buf  = gpio_nand_writebuf;
 302                 this->verify_buf = gpio_nand_verifybuf;
 303         }
 304
 305         /* set the mtd private data for the nand driver */
 306         gpiomtd->mtd_info.priv = this;
 307         gpiomtd->mtd_info.owner = THIS_MODULE;
 308
 309         if (nand_scan(&gpiomtd->mtd_info, 1)) {
 310                 dev_err(&dev->dev, "no nand chips found?\n");
 311                 ret = -ENXIO;
 312                 goto err_wp;
 313         }
 314
 315         if (gpiomtd->plat.adjust_parts)
 316                 gpiomtd->plat.adjust_parts(&gpiomtd->plat,
 317                                            gpiomtd->mtd_info.size);
 318
 319         mtd_device_register(&gpiomtd->mtd_info, gpiomtd->plat.parts,
 320                             gpiomtd->plat.num_parts);
 321         platform_set_drvdata(dev, gpiomtd);
 322
 323         return 0;
 324
 325 err_wp:
 326         if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
 327                 gpio_set_value(gpiomtd->plat.gpio_nwp, 0);
 328         gpio_free(gpiomtd->plat.gpio_rdy);
 329 err_rdy:
 330         gpio_free(gpiomtd->plat.gpio_cle);
 331 err_cle:
 332         gpio_free(gpiomtd->plat.gpio_ale);
 333 err_ale:
 334         if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
 335                 gpio_free(gpiomtd->plat.gpio_nwp);
 336 err_nwp:
 337         gpio_free(gpiomtd->plat.gpio_nce);
 338 err_nce:
 339         iounmap(gpiomtd->io_sync);
 340         if (res1)
 341                 release_mem_region(res1->start, resource_size(res1));
 342 err_sync:
 343         iounmap(gpiomtd->nand_chip.IO_ADDR_R);
 344         release_mem_region(res0->start, resource_size(res0));
 345 err_map:
 346         kfree(gpiomtd);
 347         return ret;
 348 }
 349
 350 static struct platform_driver gpio_nand_driver = {
 351         .probe          = gpio_nand_probe,
 352         .remove         = gpio_nand_remove,
 353         .driver         = {
 354                 .name   = "gpio-nand",
 355         },
 356 };
 357
 358 static int __init gpio_nand_init(void)
 359 {
 360         printk(KERN_INFO "GPIO NAND driver, © 2004 Simtec Electronics\n");
 361
 362         return platform_driver_register(&gpio_nand_driver);
 363 }
 364
 365 static void __exit gpio_nand_exit(void)
 366 {
 367         platform_driver_unregister(&gpio_nand_driver);
 368 }
 369
 370 module_init(gpio_nand_init);
 371 module_exit(gpio_nand_exit);
 372
 373 MODULE_LICENSE("GPL");
 374 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 375 MODULE_DESCRIPTION("GPIO NAND Driver");