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/mtd/mtd.h>
  17 #include <linux/mtd/nand.h>
  18 #include <linux/mtd/partitions.h>
  19 #include <linux/clk.h>
  20 #include <linux/err.h>
  21 #include <asm/io.h>
  22 #include <asm/sizes.h>
  23 #include <mach/hardware.h>
  24 #include <plat/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 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
  86         nc = kzalloc(sizeof(struct nand_chip) + sizeof(struct mtd_info), GFP_KERNEL);
  87         if (!nc) {
  88                 printk(KERN_ERR "orion_nand: failed to allocate device structure.\n");
  89                 ret = -ENOMEM;
  90                 goto no_res;
  91         }
  92         mtd = (struct mtd_info *)(nc + 1);
  93
  94         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  95         if (!res) {
  96                 ret = -ENODEV;
  97                 goto no_res;
  98         }
  99
 100         io_base = ioremap(res->start, resource_size(res));
 101         if (!io_base) {
 102                 printk(KERN_ERR "orion_nand: ioremap failed\n");
 103                 ret = -EIO;
 104                 goto no_res;
 105         }
 106
 107         board = pdev->dev.platform_data;
 108
 109         mtd->priv = nc;
 110         mtd->owner = THIS_MODULE;
 111
 112         nc->priv = board;
 113         nc->IO_ADDR_R = nc->IO_ADDR_W = io_base;
 114         nc->cmd_ctrl = orion_nand_cmd_ctrl;
 115         nc->read_buf = orion_nand_read_buf;
 116         nc->ecc.mode = NAND_ECC_SOFT;
 117
 118         if (board->chip_delay)
 119                 nc->chip_delay = board->chip_delay;
 120
 121         if (board->width == 16)
 122                 nc->options |= NAND_BUSWIDTH_16;
 123
 124         if (board->dev_ready)
 125                 nc->dev_ready = board->dev_ready;
 126
 127         platform_set_drvdata(pdev, mtd);
 128
 129         /* Not all platforms can gate the clock, so it is not
 130            an error if the clock does not exists. */
 131         clk = clk_get(&pdev->dev, NULL);
 132         if (!IS_ERR(clk)) {
 133                 clk_prepare_enable(clk);
 134                 clk_put(clk);
 135         }
 136
 137         if (nand_scan(mtd, 1)) {
 138                 ret = -ENXIO;
 139                 goto no_dev;
 140         }
 141
 142         mtd->name = "orion_nand";
 143         ret = mtd_device_parse_register(mtd, NULL, NULL, board->parts,
 144                                         board->nr_parts);
 145         if (ret) {
 146                 nand_release(mtd);
 147                 goto no_dev;
 148         }
 149
 150         return 0;
 151
 152 no_dev:
 153         platform_set_drvdata(pdev, NULL);
 154         iounmap(io_base);
 155 no_res:
 156         kfree(nc);
 157
 158         return ret;
 159 }
 160
 161 static int __devexit orion_nand_remove(struct platform_device *pdev)
 162 {
 163         struct mtd_info *mtd = platform_get_drvdata(pdev);
 164         struct nand_chip *nc = mtd->priv;
 165         struct clk *clk;
 166
 167         nand_release(mtd);
 168
 169         iounmap(nc->IO_ADDR_W);
 170
 171         kfree(nc);
 172
 173         clk = clk_get(&pdev->dev, NULL);
 174         if (!IS_ERR(clk)) {
 175                 clk_disable_unprepare(clk);
 176                 clk_put(clk);
 177         }
 178
 179         return 0;
 180 }
 181
 182 static struct platform_driver orion_nand_driver = {
 183         .remove         = __devexit_p(orion_nand_remove),
 184         .driver         = {
 185                 .name   = "orion_nand",
 186                 .owner  = THIS_MODULE,
 187         },
 188 };
 189
 190 static int __init orion_nand_init(void)
 191 {
 192         return platform_driver_probe(&orion_nand_driver, orion_nand_probe);
 193 }
 194
 195 static void __exit orion_nand_exit(void)
 196 {
 197         platform_driver_unregister(&orion_nand_driver);
 198 }
 199
 200 module_init(orion_nand_init);
 201 module_exit(orion_nand_exit);
 202
 203 MODULE_LICENSE("GPL");
 204 MODULE_AUTHOR("Tzachi Perelstein");
 205 MODULE_DESCRIPTION("NAND glue for Orion platforms");
 206 MODULE_ALIAS("platform:orion_nand");