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->priv;
  29         struct orion_nand_data *board = nc->priv;
  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->priv;
  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 mtd_part_parser_data ppdata = {};
  80         struct nand_chip *nc;
  81         struct orion_nand_data *board;
  82         struct resource *res;
  83         struct clk *clk;
  84         void __iomem *io_base;
  85         int ret = 0;
  86         u32 val = 0;
  87
  88         nc = devm_kzalloc(&pdev->dev,
  89                         sizeof(struct nand_chip) + sizeof(struct mtd_info),
  90                         GFP_KERNEL);
  91         if (!nc)
  92                 return -ENOMEM;
  93         mtd = (struct mtd_info *)(nc + 1);
  94
  95         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  96         io_base = devm_ioremap_resource(&pdev->dev, res);
  97
  98         if (IS_ERR(io_base))
  99                 return PTR_ERR(io_base);
 100
 101         if (pdev->dev.of_node) {
 102                 board = devm_kzalloc(&pdev->dev, sizeof(struct orion_nand_data),
 103                                         GFP_KERNEL);
 104                 if (!board)
 105                         return -ENOMEM;
 106                 if (!of_property_read_u32(pdev->dev.of_node, "cle", &val))
 107                         board->cle = (u8)val;
 108                 else
 109                         board->cle = 0;
 110                 if (!of_property_read_u32(pdev->dev.of_node, "ale", &val))
 111                         board->ale = (u8)val;
 112                 else
 113                         board->ale = 1;
 114                 if (!of_property_read_u32(pdev->dev.of_node,
 115                                                 "bank-width", &val))
 116                         board->width = (u8)val * 8;
 117                 else
 118                         board->width = 8;
 119                 if (!of_property_read_u32(pdev->dev.of_node,
 120                                                 "chip-delay", &val))
 121                         board->chip_delay = (u8)val;
 122         } else {
 123                 board = dev_get_platdata(&pdev->dev);
 124         }
 125
 126         mtd->priv = nc;
 127         mtd->owner = THIS_MODULE;
 128
 129         nc->priv = board;
 130         nc->IO_ADDR_R = nc->IO_ADDR_W = io_base;
 131         nc->cmd_ctrl = orion_nand_cmd_ctrl;
 132         nc->read_buf = orion_nand_read_buf;
 133         nc->ecc.mode = NAND_ECC_SOFT;
 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         if (nand_scan(mtd, 1)) {
 159                 ret = -ENXIO;
 160                 goto no_dev;
 161         }
 162
 163         mtd->name = "orion_nand";
 164         ppdata.of_node = pdev->dev.of_node;
 165         ret = mtd_device_parse_register(mtd, NULL, &ppdata,
 166                         board->parts, board->nr_parts);
 167         if (ret) {
 168                 nand_release(mtd);
 169                 goto no_dev;
 170         }
 171
 172         return 0;
 173
 174 no_dev:
 175         if (!IS_ERR(clk)) {
 176                 clk_disable_unprepare(clk);
 177                 clk_put(clk);
 178         }
 179
 180         return ret;
 181 }
 182
 183 static int orion_nand_remove(struct platform_device *pdev)
 184 {
 185         struct mtd_info *mtd = platform_get_drvdata(pdev);
 186         struct clk *clk;
 187
 188         nand_release(mtd);
 189
 190         clk = clk_get(&pdev->dev, NULL);
 191         if (!IS_ERR(clk)) {
 192                 clk_disable_unprepare(clk);
 193                 clk_put(clk);
 194         }
 195
 196         return 0;
 197 }
 198
 199 #ifdef CONFIG_OF
 200 static const struct of_device_id orion_nand_of_match_table[] = {
 201         { .compatible = "marvell,orion-nand", },
 202         {},
 203 };
 204 #endif
 205
 206 static struct platform_driver orion_nand_driver = {
 207         .remove         = orion_nand_remove,
 208         .driver         = {
 209                 .name   = "orion_nand",
 210                 .of_match_table = of_match_ptr(orion_nand_of_match_table),
 211         },
 212 };
 213
 214 module_platform_driver_probe(orion_nand_driver, orion_nand_probe);
 215
 216 MODULE_LICENSE("GPL");
 217 MODULE_AUTHOR("Tzachi Perelstein");
 218 MODULE_DESCRIPTION("NAND glue for Orion platforms");
 219 MODULE_ALIAS("platform:orion_nand");