target/linux/ar71xx/files/drivers/mtd/nand/rb750_nand.c

   1 /*
   2  *  NAND flash driver for the MikroTik RouterBOARD 750
   3  *
   4  *  Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify it
   7  *  under the terms of the GNU General Public License version 2 as published
   8  *  by the Free Software Foundation.
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/mtd/nand.h>
  13 #include <linux/mtd/mtd.h>
  14 #include <linux/mtd/partitions.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/io.h>
  17 #include <linux/slab.h>
  18
  19 #include <asm/mach-ar71xx/ar71xx.h>
  20 #include <asm/mach-ar71xx/mach-rb750.h>
  21
  22 #define DRV_NAME        "rb750-nand"
  23 #define DRV_VERSION     "0.1.0"
  24 #define DRV_DESC        "NAND flash driver for the RouterBOARD 750"
  25
  26 #define RB750_NAND_IO0          BIT(RB750_GPIO_NAND_IO0)
  27 #define RB750_NAND_ALE          BIT(RB750_GPIO_NAND_ALE)
  28 #define RB750_NAND_CLE          BIT(RB750_GPIO_NAND_CLE)
  29 #define RB750_NAND_NRE          BIT(RB750_GPIO_NAND_NRE)
  30 #define RB750_NAND_NWE          BIT(RB750_GPIO_NAND_NWE)
  31 #define RB750_NAND_RDY          BIT(RB750_GPIO_NAND_RDY)
  32 #define RB750_NAND_NCE          BIT(RB750_GPIO_NAND_NCE)
  33
  34 #define RB750_NAND_DATA_SHIFT   1
  35 #define RB750_NAND_DATA_BITS    (0xff << RB750_NAND_DATA_SHIFT)
  36 #define RB750_NAND_INPUT_BITS   (RB750_NAND_DATA_BITS | RB750_NAND_RDY)
  37 #define RB750_NAND_OUTPUT_BITS  (RB750_NAND_ALE | RB750_NAND_CLE | \
  38                                  RB750_NAND_NRE | RB750_NAND_NWE | \
  39                                  RB750_NAND_NCE)
  40
  41 struct rb750_nand_info {
  42         struct nand_chip        chip;
  43         struct mtd_info         mtd;
  44 };
  45
  46 /*
  47  * We need to use the OLD Yaffs-1 OOB layout, otherwise the RB bootloader
  48  * will not be able to find the kernel that we load.
  49  */
  50 static struct nand_ecclayout rb750_nand_ecclayout = {
  51         .eccbytes       = 6,
  52         .eccpos         = { 8, 9, 10, 13, 14, 15 },
  53         .oobavail       = 9,
  54         .oobfree        = { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
  55 };
  56
  57 static struct mtd_partition rb750_nand_partitions[] = {
  58         {
  59                 .name   = "booter",
  60                 .offset = 0,
  61                 .size   = (256 * 1024),
  62                 .mask_flags = MTD_WRITEABLE,
  63         }, {
  64                 .name   = "kernel",
  65                 .offset = (256 * 1024),
  66                 .size   = (4 * 1024 * 1024) - (256 * 1024),
  67         }, {
  68                 .name   = "rootfs",
  69                 .offset = MTDPART_OFS_NXTBLK,
  70                 .size   = MTDPART_SIZ_FULL,
  71         },
  72 };
  73
  74 static void rb750_nand_write(const u8 *buf, unsigned len)
  75 {
  76         void __iomem *base = ar71xx_gpio_base;
  77         u32 out;
  78         unsigned i;
  79
  80         /* set data lines to output mode */
  81         __raw_writel(__raw_readl(base + GPIO_REG_OE) | RB750_NAND_DATA_BITS,
  82                      base + GPIO_REG_OE);
  83
  84         out = __raw_readl(base + GPIO_REG_OUT);
  85         out &= ~(RB750_NAND_DATA_BITS | RB750_NAND_NWE);
  86         for (i = 0; i != len; i++) {
  87                 u32 data;
  88
  89                 data = buf[i];
  90                 data <<= RB750_NAND_DATA_SHIFT;
  91                 data |= out;
  92                 __raw_writel(data, base + GPIO_REG_OUT);
  93
  94                 __raw_writel(data | RB750_NAND_NWE, base + GPIO_REG_OUT);
  95                 /* flush write */
  96                 __raw_readl(base + GPIO_REG_OUT);
  97         }
  98
  99         /* set data lines to input mode */
 100         __raw_writel(__raw_readl(base + GPIO_REG_OE) & ~RB750_NAND_DATA_BITS,
 101                      base + GPIO_REG_OE);
 102         /* flush write */
 103         __raw_readl(base + GPIO_REG_OE);
 104 }
 105
 106 static int rb750_nand_read_verify(u8 *read_buf, unsigned len,
 107                                   const u8 *verify_buf)
 108 {
 109         void __iomem *base = ar71xx_gpio_base;
 110         unsigned i;
 111
 112         for (i = 0; i < len; i++) {
 113                 u8 data;
 114
 115                 /* activate RE line */
 116                 __raw_writel(RB750_NAND_NRE, base + GPIO_REG_CLEAR);
 117                 /* flush write */
 118                 __raw_readl(base + GPIO_REG_CLEAR);
 119
 120                 /* read input lines */
 121                 data = __raw_readl(base + GPIO_REG_IN) >> RB750_NAND_DATA_SHIFT;
 122
 123                 /* deactivate RE line */
 124                 __raw_writel(RB750_NAND_NRE, base + GPIO_REG_SET);
 125
 126                 if (read_buf)
 127                         read_buf[i] = data;
 128                 else if (verify_buf && verify_buf[i] != data)
 129                         return -EFAULT;
 130         }
 131
 132         return 0;
 133 }
 134
 135 static void rb750_nand_select_chip(struct mtd_info *mtd, int chip)
 136 {
 137         void __iomem *base = ar71xx_gpio_base;
 138         u32 func;
 139
 140         func = __raw_readl(base + GPIO_REG_FUNC);
 141         if (chip >= 0) {
 142                 /* disable latch */
 143                 rb750_latch_change(RB750_LVC573_LE, 0);
 144
 145                 /* disable alternate functions */
 146                 ar71xx_gpio_function_setup(AR724X_GPIO_FUNC_JTAG_DISABLE,
 147                                            AR724X_GPIO_FUNC_SPI_EN);
 148
 149                 /* set input mode for data lines */
 150                 __raw_writel(__raw_readl(base + GPIO_REG_OE) &
 151                              ~RB750_NAND_INPUT_BITS,
 152                              base + GPIO_REG_OE);
 153
 154                 /* deactivate RE and WE lines */
 155                 __raw_writel(RB750_NAND_NRE | RB750_NAND_NWE,
 156                              base + GPIO_REG_SET);
 157                 /* flush write */
 158                 (void) __raw_readl(base + GPIO_REG_SET);
 159
 160                 /* activate CE line */
 161                 __raw_writel(RB750_NAND_NCE, base + GPIO_REG_CLEAR);
 162         } else {
 163                 /* deactivate CE line */
 164                 __raw_writel(RB750_NAND_NCE, base + GPIO_REG_SET);
 165                 /* flush write */
 166                 (void) __raw_readl(base + GPIO_REG_SET);
 167
 168                 __raw_writel(__raw_readl(base + GPIO_REG_OE) |
 169                              RB750_NAND_IO0 | RB750_NAND_RDY,
 170                              base + GPIO_REG_OE);
 171
 172                 /* restore alternate functions */
 173                 ar71xx_gpio_function_setup(AR724X_GPIO_FUNC_SPI_EN,
 174                                            AR724X_GPIO_FUNC_JTAG_DISABLE);
 175
 176                 /* enable latch */
 177                 rb750_latch_change(0, RB750_LVC573_LE);
 178         }
 179 }
 180
 181 static int rb750_nand_dev_ready(struct mtd_info *mtd)
 182 {
 183         void __iomem *base = ar71xx_gpio_base;
 184
 185         return !!(__raw_readl(base + GPIO_REG_IN) & RB750_NAND_RDY);
 186 }
 187
 188 static void rb750_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
 189                                 unsigned int ctrl)
 190 {
 191         if (ctrl & NAND_CTRL_CHANGE) {
 192                 void __iomem *base = ar71xx_gpio_base;
 193                 u32 t;
 194
 195                 t = __raw_readl(base + GPIO_REG_OUT);
 196
 197                 t &= ~(RB750_NAND_CLE | RB750_NAND_ALE);
 198                 t |= (ctrl & NAND_CLE) ? RB750_NAND_CLE : 0;
 199                 t |= (ctrl & NAND_ALE) ? RB750_NAND_ALE : 0;
 200
 201                 __raw_writel(t, base + GPIO_REG_OUT);
 202                 /* flush write */
 203                 __raw_readl(base + GPIO_REG_OUT);
 204         }
 205
 206         if (cmd != NAND_CMD_NONE) {
 207                 u8 t = cmd;
 208                 rb750_nand_write(&t, 1);
 209         }
 210 }
 211
 212 static u8 rb750_nand_read_byte(struct mtd_info *mtd)
 213 {
 214         u8 data = 0;
 215         rb750_nand_read_verify(&data, 1, NULL);
 216         return data;
 217 }
 218
 219 static void rb750_nand_read_buf(struct mtd_info *mtd, u8 *buf, int len)
 220 {
 221         rb750_nand_read_verify(buf, len, NULL);
 222 }
 223
 224 static void rb750_nand_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
 225 {
 226         rb750_nand_write(buf, len);
 227 }
 228
 229 static int rb750_nand_verify_buf(struct mtd_info *mtd, const u8 *buf, int len)
 230 {
 231         return rb750_nand_read_verify(NULL, len, buf);
 232 }
 233
 234 static void __init rb750_nand_gpio_init(void)
 235 {
 236         void __iomem *base = ar71xx_gpio_base;
 237         u32 out;
 238
 239         out = __raw_readl(base + GPIO_REG_OUT);
 240
 241         /* setup output levels */
 242         __raw_writel(RB750_NAND_NCE | RB750_NAND_NRE | RB750_NAND_NWE,
 243                      base + GPIO_REG_SET);
 244
 245         __raw_writel(RB750_NAND_ALE | RB750_NAND_CLE,
 246                      base + GPIO_REG_CLEAR);
 247
 248         /* setup input lines */
 249         __raw_writel(__raw_readl(base + GPIO_REG_OE) & ~(RB750_NAND_INPUT_BITS),
 250                      base + GPIO_REG_OE);
 251
 252         /* setup output lines */
 253         __raw_writel(__raw_readl(base + GPIO_REG_OE) | RB750_NAND_OUTPUT_BITS,
 254                      base + GPIO_REG_OE);
 255
 256         rb750_latch_change(~out & RB750_NAND_IO0, out & RB750_NAND_IO0);
 257 }
 258
 259 static int __init rb750_nand_probe(struct platform_device *pdev)
 260 {
 261         struct rb750_nand_info  *info;
 262         int ret;
 263
 264         printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
 265
 266         rb750_nand_gpio_init();
 267
 268         info = kzalloc(sizeof(*info), GFP_KERNEL);
 269         if (!info)
 270                 return -ENOMEM;
 271
 272         info->chip.priv = &info;
 273         info->mtd.priv  = &info->chip;
 274         info->mtd.owner = THIS_MODULE;
 275
 276         info->chip.select_chip  = rb750_nand_select_chip;
 277         info->chip.cmd_ctrl     = rb750_nand_cmd_ctrl;
 278         info->chip.dev_ready    = rb750_nand_dev_ready;
 279         info->chip.read_byte    = rb750_nand_read_byte;
 280         info->chip.write_buf    = rb750_nand_write_buf;
 281         info->chip.read_buf     = rb750_nand_read_buf;
 282         info->chip.verify_buf   = rb750_nand_verify_buf;
 283
 284         info->chip.chip_delay   = 25;
 285         info->chip.ecc.mode     = NAND_ECC_SOFT;
 286         info->chip.options      |= NAND_NO_AUTOINCR;
 287
 288         platform_set_drvdata(pdev, info);
 289
 290         ret = nand_scan_ident(&info->mtd, 1);
 291         if (ret) {
 292                 ret = -ENXIO;
 293                 goto err_free_info;
 294         }
 295
 296         if (info->mtd.writesize == 512)
 297                 info->chip.ecc.layout = &rb750_nand_ecclayout;
 298
 299         ret = nand_scan_tail(&info->mtd);
 300         if (ret) {
 301                 return -ENXIO;
 302                 goto err_set_drvdata;
 303         }
 304
 305 #ifdef CONFIG_MTD_PARTITIONS
 306         ret = add_mtd_partitions(&info->mtd, rb750_nand_partitions,
 307                                  ARRAY_SIZE(rb750_nand_partitions));
 308 #else
 309         ret = add_mtd_device(&info->mtd);
 310 #endif
 311         if (ret)
 312                 goto err_release_nand;
 313
 314         return 0;
 315
 316 err_release_nand:
 317         nand_release(&info->mtd);
 318 err_set_drvdata:
 319         platform_set_drvdata(pdev, NULL);
 320 err_free_info:
 321         kfree(info);
 322         return ret;
 323 }
 324
 325 static int __devexit rb750_nand_remove(struct platform_device *pdev)
 326 {
 327         struct rb750_nand_info *info = platform_get_drvdata(pdev);
 328
 329         nand_release(&info->mtd);
 330         platform_set_drvdata(pdev, NULL);
 331         kfree(info);
 332
 333         return 0;
 334 }
 335
 336 static struct platform_driver rb750_nand_driver = {
 337         .probe  = rb750_nand_probe,
 338         .remove = __devexit_p(rb750_nand_remove),
 339         .driver = {
 340                 .name   = DRV_NAME,
 341                 .owner  = THIS_MODULE,
 342         },
 343 };
 344
 345 static int __init rb750_nand_init(void)
 346 {
 347         return platform_driver_register(&rb750_nand_driver);
 348 }
 349
 350 static void __exit rb750_nand_exit(void)
 351 {
 352         platform_driver_unregister(&rb750_nand_driver);
 353 }
 354
 355 module_init(rb750_nand_init);
 356 module_exit(rb750_nand_exit);
 357
 358 MODULE_DESCRIPTION(DRV_DESC);
 359 MODULE_VERSION(DRV_VERSION);
 360 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
 361 MODULE_LICENSE("GPL v2");