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 static void orion_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
  27 {
  28         struct nand_chip *nc = mtd_to_nand(mtd);
  29         struct orion_nand_data *board = nand_get_controller_data(nc);
  30         u32 offs;
  31
  32         if (cmd == NAND_CMD_NONE)
  33                 return;
  34
  35         if (ctrl & NAND_CLE)
  36                 offs = (1 << board->cle);
  37         else if (ctrl & NAND_ALE)
  38                 offs = (1 << board->ale);
  39         else
  40                 return;
  41
  42         if (nc->options & NAND_BUSWIDTH_16)
  43                 offs <<= 1;
  44
  45         writeb(cmd, nc->IO_ADDR_W + offs);
  46 }
  47
  48 static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
  49 {
  50         struct nand_chip *chip = mtd_to_nand(mtd);
  51         void __iomem *io_base = chip->IO_ADDR_R;
  52         uint64_t *buf64;
  53         int i = 0;
  54
  55         while (len && (unsigned long)buf & 7) {
  56                 *buf++ = readb(io_base);
  57                 len--;
  58         }
  59         buf64 = (uint64_t *)buf;
  60         while (i < len/8) {
  61                 /*
  62                  * Since GCC has no proper constraint (PR 43518)
  63                  * force x variable to r2/r3 registers as ldrd instruction
  64                  * requires first register to be even.
  65                  */
  66                 register uint64_t x asm ("r2");
  67
  68                 asm volatile ("ldrd\t%0, [%1]" : "=&r" (x) : "r" (io_base));
  69                 buf64[i++] = x;
  70         }
  71         i *= 8;
  72         while (i < len)
  73                 buf[i++] = readb(io_base);
  74 }
  75
  76 static int __init orion_nand_probe(struct platform_device *pdev)
  77 {
  78         struct mtd_info *mtd;
  79         struct nand_chip *nc;
  80         struct orion_nand_data *board;
  81         struct resource *res;
  82         struct clk *clk;
  83         void __iomem *io_base;
  84         int ret = 0;
  85         u32 val = 0;
  86
  87         nc = devm_kzalloc(&pdev->dev,
  88                         sizeof(struct nand_chip),
  89                         GFP_KERNEL);
  90         if (!nc)
  91                 return -ENOMEM;
  92         mtd = nand_to_mtd(nc);
  93
  94         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  95         io_base = devm_ioremap_resource(&pdev->dev, res);
  96
  97         if (IS_ERR(io_base))
  98                 return PTR_ERR(io_base);
  99
 100         if (pdev->dev.of_node) {
 101                 board = devm_kzalloc(&pdev->dev, sizeof(struct orion_nand_data),
 102                                         GFP_KERNEL);
 103                 if (!board)
 104                         return -ENOMEM;
 105                 if (!of_property_read_u32(pdev->dev.of_node, "cle", &val))
 106                         board->cle = (u8)val;
 107                 else
 108                         board->cle = 0;
 109                 if (!of_property_read_u32(pdev->dev.of_node, "ale", &val))
 110                         board->ale = (u8)val;
 111                 else
 112                         board->ale = 1;
 113                 if (!of_property_read_u32(pdev->dev.of_node,
 114                                                 "bank-width", &val))
 115                         board->width = (u8)val * 8;
 116                 else
 117                         board->width = 8;
 118                 if (!of_property_read_u32(pdev->dev.of_node,
 119                                                 "chip-delay", &val))
 120                         board->chip_delay = (u8)val;
 121         } else {
 122                 board = dev_get_platdata(&pdev->dev);
 123         }
 124
 125         mtd->dev.parent = &pdev->dev;
 126
 127         nand_set_controller_data(nc, board);
 128         nand_set_flash_node(nc, pdev->dev.of_node);
 129         nc->IO_ADDR_R = nc->IO_ADDR_W = io_base;
 130         nc->cmd_ctrl = orion_nand_cmd_ctrl;
 131         nc->read_buf = orion_nand_read_buf;
 132         nc->ecc.mode = NAND_ECC_SOFT;
 133         nc->ecc.algo = NAND_ECC_HAMMING;
 134
 135         if (board->chip_delay)
 136                 nc->chip_delay = board->chip_delay;
 137
 138         WARN(board->width > 16,
 139                 "%d bit bus width out of range",
 140                 board->width);
 141
 142         if (board->width == 16)
 143                 nc->options |= NAND_BUSWIDTH_16;
 144
 145         if (board->dev_ready)
 146                 nc->dev_ready = board->dev_ready;
 147
 148         platform_set_drvdata(pdev, mtd);
 149
 150         /* Not all platforms can gate the clock, so it is not
 151            an error if the clock does not exists. */
 152         clk = clk_get(&pdev->dev, NULL);
 153         if (!IS_ERR(clk)) {
 154                 clk_prepare_enable(clk);
 155                 clk_put(clk);
 156         }
 157
 158         ret = nand_scan(mtd, 1);
 159         if (ret)
 160                 goto no_dev;
 161
 162         mtd->name = "orion_nand";
 163         ret = mtd_device_register(mtd, board->parts, board->nr_parts);
 164         if (ret) {
 165                 nand_release(mtd);
 166                 goto no_dev;
 167         }
 168
 169         return 0;
 170
 171 no_dev:
 172         if (!IS_ERR(clk)) {
 173                 clk_disable_unprepare(clk);
 174                 clk_put(clk);
 175         }
 176
 177         return ret;
 178 }
 179
 180 static int orion_nand_remove(struct platform_device *pdev)
 181 {
 182         struct mtd_info *mtd = platform_get_drvdata(pdev);
 183         struct clk *clk;
 184
 185         nand_release(mtd);
 186
 187         clk = clk_get(&pdev->dev, NULL);
 188         if (!IS_ERR(clk)) {
 189                 clk_disable_unprepare(clk);
 190                 clk_put(clk);
 191         }
 192
 193         return 0;
 194 }
 195
 196 #ifdef CONFIG_OF
 197 static const struct of_device_id orion_nand_of_match_table[] = {
 198         { .compatible = "marvell,orion-nand", },
 199         {},
 200 };
 201 MODULE_DEVICE_TABLE(of, orion_nand_of_match_table);
 202 #endif
 203
 204 static struct platform_driver orion_nand_driver = {
 205         .remove         = orion_nand_remove,
 206         .driver         = {
 207                 .name   = "orion_nand",
 208                 .of_match_table = of_match_ptr(orion_nand_of_match_table),
 209         },
 210 };
 211
 212 module_platform_driver_probe(orion_nand_driver, orion_nand_probe);
 213
 214 MODULE_LICENSE("GPL");
 215 MODULE_AUTHOR("Tzachi Perelstein");
 216 MODULE_DESCRIPTION("NAND glue for Orion platforms");
 217 MODULE_ALIAS("platform:orion_nand");