drivers/mtd/nand/orion_nand.c

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