drivers/mtd/nand/raw/orion_nand.c

   1 /*
   2  * NAND support for Marvell Orion SoC platforms
   3  *
   4  * Tzachi Perelstein <tzachi@marvell.com>
   5  *
   6  * This file is licensed under  the terms of the GNU General Public
   7  * License version 2. This program is licensed "as is" without any
   8  * warranty of any kind, whether express or implied.
   9  */
  10
  11 #include <linux/slab.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/of.h>
  15 #include <linux/mtd/mtd.h>
  16 #include <linux/mtd/rawnand.h>
  17 #include <linux/mtd/partitions.h>
  18 #include <linux/clk.h>
  19 #include <linux/err.h>
  20 #include <linux/io.h>
  21 #include <linux/sizes.h>
  22 #include <linux/platform_data/mtd-orion_nand.h>
  23
  24 struct orion_nand_info {
  25         struct nand_controller controller;
  26         struct nand_chip chip;
  27         struct clk *clk;
  28 };
  29
  30 static void orion_nand_cmd_ctrl(struct nand_chip *nc, int cmd,
  31                                 unsigned int ctrl)
  32 {
  33         struct orion_nand_data *board = nand_get_controller_data(nc);
  34         u32 offs;
  35
  36         if (cmd == NAND_CMD_NONE)
  37                 return;
  38
  39         if (ctrl & NAND_CLE)
  40                 offs = (1 << board->cle);
  41         else if (ctrl & NAND_ALE)
  42                 offs = (1 << board->ale);
  43         else
  44                 return;
  45
  46         if (nc->options & NAND_BUSWIDTH_16)
  47                 offs <<= 1;
  48
  49         writeb(cmd, nc->legacy.IO_ADDR_W + offs);
  50 }
  51
  52 static void orion_nand_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
  53 {
  54         void __iomem *io_base = chip->legacy.IO_ADDR_R;
  55 #if defined(__LINUX_ARM_ARCH__) && __LINUX_ARM_ARCH__ >= 5
  56         uint64_t *buf64;
  57 #endif
  58         int i = 0;
  59
  60         while (len && (unsigned long)buf & 7) {
  61                 *buf++ = readb(io_base);
  62                 len--;
  63         }
  64 #if defined(__LINUX_ARM_ARCH__) && __LINUX_ARM_ARCH__ >= 5
  65         buf64 = (uint64_t *)buf;
  66         while (i < len/8) {
  67                 /*
  68                  * Since GCC has no proper constraint (PR 43518)
  69                  * force x variable to r2/r3 registers as ldrd instruction
  70                  * requires first register to be even.
  71                  */
  72                 register uint64_t x asm ("r2");
  73
  74                 asm volatile ("ldrd\t%0, [%1]" : "=&r" (x) : "r" (io_base));
  75                 buf64[i++] = x;
  76         }
  77         i *= 8;
  78 #else
  79         readsl(io_base, buf, len/4);
  80         i = len / 4 * 4;
  81 #endif
  82         while (i < len)
  83                 buf[i++] = readb(io_base);
  84 }
  85
  86 static int orion_nand_attach_chip(struct nand_chip *chip)
  87 {
  88         chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
  89
  90         if (chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN)
  91                 chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
  92
  93         return 0;
  94 }
  95
  96 static const struct nand_controller_ops orion_nand_ops = {
  97         .attach_chip = orion_nand_attach_chip,
  98 };
  99
 100 static int __init orion_nand_probe(struct platform_device *pdev)
 101 {
 102         struct orion_nand_info *info;
 103         struct mtd_info *mtd;
 104         struct nand_chip *nc;
 105         struct orion_nand_data *board;
 106         struct resource *res;
 107         void __iomem *io_base;
 108         int ret = 0;
 109         u32 val = 0;
 110
 111         info = devm_kzalloc(&pdev->dev,
 112                         sizeof(struct orion_nand_info),
 113                         GFP_KERNEL);
 114         if (!info)
 115                 return -ENOMEM;
 116         nc = &info->chip;
 117         mtd = nand_to_mtd(nc);
 118
 119         nand_controller_init(&info->controller);
 120         info->controller.ops = &orion_nand_ops;
 121         nc->controller = &info->controller;
 122
 123         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 124         io_base = devm_ioremap_resource(&pdev->dev, res);
 125
 126         if (IS_ERR(io_base))
 127                 return PTR_ERR(io_base);
 128
 129         if (pdev->dev.of_node) {
 130                 board = devm_kzalloc(&pdev->dev, sizeof(struct orion_nand_data),
 131                                         GFP_KERNEL);
 132                 if (!board)
 133                         return -ENOMEM;
 134                 if (!of_property_read_u32(pdev->dev.of_node, "cle", &val))
 135                         board->cle = (u8)val;
 136                 else
 137                         board->cle = 0;
 138                 if (!of_property_read_u32(pdev->dev.of_node, "ale", &val))
 139                         board->ale = (u8)val;
 140                 else
 141                         board->ale = 1;
 142                 if (!of_property_read_u32(pdev->dev.of_node,
 143                                                 "bank-width", &val))
 144                         board->width = (u8)val * 8;
 145                 else
 146                         board->width = 8;
 147                 if (!of_property_read_u32(pdev->dev.of_node,
 148                                                 "chip-delay", &val))
 149                         board->chip_delay = (u8)val;
 150         } else {
 151                 board = dev_get_platdata(&pdev->dev);
 152         }
 153
 154         mtd->dev.parent = &pdev->dev;
 155
 156         nand_set_controller_data(nc, board);
 157         nand_set_flash_node(nc, pdev->dev.of_node);
 158         nc->legacy.IO_ADDR_R = nc->legacy.IO_ADDR_W = io_base;
 159         nc->legacy.cmd_ctrl = orion_nand_cmd_ctrl;
 160         nc->legacy.read_buf = orion_nand_read_buf;
 161
 162         if (board->chip_delay)
 163                 nc->legacy.chip_delay = board->chip_delay;
 164
 165         WARN(board->width > 16,
 166                 "%d bit bus width out of range",
 167                 board->width);
 168
 169         if (board->width == 16)
 170                 nc->options |= NAND_BUSWIDTH_16;
 171
 172         platform_set_drvdata(pdev, info);
 173
 174         /* Not all platforms can gate the clock, so it is not
 175            an error if the clock does not exists. */
 176         info->clk = devm_clk_get(&pdev->dev, NULL);
 177         if (IS_ERR(info->clk)) {
 178                 ret = PTR_ERR(info->clk);
 179                 if (ret == -ENOENT) {
 180                         info->clk = NULL;
 181                 } else {
 182                         dev_err(&pdev->dev, "failed to get clock!\n");
 183                         return ret;
 184                 }
 185         }
 186
 187         ret = clk_prepare_enable(info->clk);
 188         if (ret) {
 189                 dev_err(&pdev->dev, "failed to prepare clock!\n");
 190                 return ret;
 191         }
 192
 193         ret = nand_scan(nc, 1);
 194         if (ret)
 195                 goto no_dev;
 196
 197         mtd->name = "orion_nand";
 198         ret = mtd_device_register(mtd, board->parts, board->nr_parts);
 199         if (ret) {
 200                 nand_cleanup(nc);
 201                 goto no_dev;
 202         }
 203
 204         return 0;
 205
 206 no_dev:
 207         clk_disable_unprepare(info->clk);
 208         return ret;
 209 }
 210
 211 static int orion_nand_remove(struct platform_device *pdev)
 212 {
 213         struct orion_nand_info *info = platform_get_drvdata(pdev);
 214         struct nand_chip *chip = &info->chip;
 215         int ret;
 216
 217         ret = mtd_device_unregister(nand_to_mtd(chip));
 218         WARN_ON(ret);
 219
 220         nand_cleanup(chip);
 221
 222         clk_disable_unprepare(info->clk);
 223
 224         return 0;
 225 }
 226
 227 #ifdef CONFIG_OF
 228 static const struct of_device_id orion_nand_of_match_table[] = {
 229         { .compatible = "marvell,orion-nand", },
 230         {},
 231 };
 232 MODULE_DEVICE_TABLE(of, orion_nand_of_match_table);
 233 #endif
 234
 235 static struct platform_driver orion_nand_driver = {
 236         .remove         = orion_nand_remove,
 237         .driver         = {
 238                 .name   = "orion_nand",
 239                 .of_match_table = of_match_ptr(orion_nand_of_match_table),
 240         },
 241 };
 242
 243 module_platform_driver_probe(orion_nand_driver, orion_nand_probe);
 244
 245 MODULE_LICENSE("GPL");
 246 MODULE_AUTHOR("Tzachi Perelstein");
 247 MODULE_DESCRIPTION("NAND glue for Orion platforms");
 248 MODULE_ALIAS("platform:orion_nand");