drivers/mtd/nand/xway_nand.c

   1 /*
   2  *  This program is free software; you can redistribute it and/or modify it
   3  *  under the terms of the GNU General Public License version 2 as published
   4  *  by the Free Software Foundation.
   5  *
   6  *  Copyright © 2012 John Crispin <blogic@openwrt.org>
   7  */
   8
   9 #include <linux/mtd/nand.h>
  10 #include <linux/of_gpio.h>
  11 #include <linux/of_platform.h>
  12
  13 #include <lantiq_soc.h>
  14
  15 /* nand registers */
  16 #define EBU_ADDSEL1             0x24
  17 #define EBU_NAND_CON            0xB0
  18 #define EBU_NAND_WAIT           0xB4
  19 #define EBU_NAND_ECC0           0xB8
  20 #define EBU_NAND_ECC_AC         0xBC
  21
  22 /* nand commands */
  23 #define NAND_CMD_ALE            (1 << 2)
  24 #define NAND_CMD_CLE            (1 << 3)
  25 #define NAND_CMD_CS             (1 << 4)
  26 #define NAND_WRITE_CMD_RESET    0xff
  27 #define NAND_WRITE_CMD          (NAND_CMD_CS | NAND_CMD_CLE)
  28 #define NAND_WRITE_ADDR         (NAND_CMD_CS | NAND_CMD_ALE)
  29 #define NAND_WRITE_DATA         (NAND_CMD_CS)
  30 #define NAND_READ_DATA          (NAND_CMD_CS)
  31 #define NAND_WAIT_WR_C          (1 << 3)
  32 #define NAND_WAIT_RD            (0x1)
  33
  34 /* we need to tel the ebu which addr we mapped the nand to */
  35 #define ADDSEL1_MASK(x)         (x << 4)
  36 #define ADDSEL1_REGEN           1
  37
  38 /* we need to tell the EBU that we have nand attached and set it up properly */
  39 #define BUSCON1_SETUP           (1 << 22)
  40 #define BUSCON1_BCGEN_RES       (0x3 << 12)
  41 #define BUSCON1_WAITWRC2        (2 << 8)
  42 #define BUSCON1_WAITRDC2        (2 << 6)
  43 #define BUSCON1_HOLDC1          (1 << 4)
  44 #define BUSCON1_RECOVC1         (1 << 2)
  45 #define BUSCON1_CMULT4          1
  46
  47 #define NAND_CON_CE             (1 << 20)
  48 #define NAND_CON_OUT_CS1        (1 << 10)
  49 #define NAND_CON_IN_CS1         (1 << 8)
  50 #define NAND_CON_PRE_P          (1 << 7)
  51 #define NAND_CON_WP_P           (1 << 6)
  52 #define NAND_CON_SE_P           (1 << 5)
  53 #define NAND_CON_CS_P           (1 << 4)
  54 #define NAND_CON_CSMUX          (1 << 1)
  55 #define NAND_CON_NANDM          1
  56
  57 static void xway_reset_chip(struct nand_chip *chip)
  58 {
  59         unsigned long nandaddr = (unsigned long) chip->IO_ADDR_W;
  60         unsigned long flags;
  61
  62         nandaddr &= ~NAND_WRITE_ADDR;
  63         nandaddr |= NAND_WRITE_CMD;
  64
  65         /* finish with a reset */
  66         spin_lock_irqsave(&ebu_lock, flags);
  67         writeb(NAND_WRITE_CMD_RESET, (void __iomem *) nandaddr);
  68         while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
  69                 ;
  70         spin_unlock_irqrestore(&ebu_lock, flags);
  71 }
  72
  73 static void xway_select_chip(struct mtd_info *mtd, int chip)
  74 {
  75
  76         switch (chip) {
  77         case -1:
  78                 ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
  79                 ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
  80                 break;
  81         case 0:
  82                 ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
  83                 ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
  84                 break;
  85         default:
  86                 BUG();
  87         }
  88 }
  89
  90 static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
  91 {
  92         struct nand_chip *this = mtd_to_nand(mtd);
  93         unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
  94         unsigned long flags;
  95
  96         if (ctrl & NAND_CTRL_CHANGE) {
  97                 nandaddr &= ~(NAND_WRITE_CMD | NAND_WRITE_ADDR);
  98                 if (ctrl & NAND_CLE)
  99                         nandaddr |= NAND_WRITE_CMD;
 100                 else
 101                         nandaddr |= NAND_WRITE_ADDR;
 102                 this->IO_ADDR_W = (void __iomem *) nandaddr;
 103         }
 104
 105         if (cmd != NAND_CMD_NONE) {
 106                 spin_lock_irqsave(&ebu_lock, flags);
 107                 writeb(cmd, this->IO_ADDR_W);
 108                 while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
 109                         ;
 110                 spin_unlock_irqrestore(&ebu_lock, flags);
 111         }
 112 }
 113
 114 static int xway_dev_ready(struct mtd_info *mtd)
 115 {
 116         return ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_RD;
 117 }
 118
 119 static unsigned char xway_read_byte(struct mtd_info *mtd)
 120 {
 121         struct nand_chip *this = mtd_to_nand(mtd);
 122         unsigned long nandaddr = (unsigned long) this->IO_ADDR_R;
 123         unsigned long flags;
 124         int ret;
 125
 126         spin_lock_irqsave(&ebu_lock, flags);
 127         ret = ltq_r8((void __iomem *)(nandaddr + NAND_READ_DATA));
 128         spin_unlock_irqrestore(&ebu_lock, flags);
 129
 130         return ret;
 131 }
 132
 133 static int xway_nand_probe(struct platform_device *pdev)
 134 {
 135         struct nand_chip *this = platform_get_drvdata(pdev);
 136         unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
 137         const __be32 *cs = of_get_property(pdev->dev.of_node,
 138                                         "lantiq,cs", NULL);
 139         u32 cs_flag = 0;
 140
 141         /* load our CS from the DT. Either we find a valid 1 or default to 0 */
 142         if (cs && (*cs == 1))
 143                 cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;
 144
 145         /* setup the EBU to run in NAND mode on our base addr */
 146         ltq_ebu_w32(CPHYSADDR(nandaddr)
 147                 | ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);
 148
 149         ltq_ebu_w32(BUSCON1_SETUP | BUSCON1_BCGEN_RES | BUSCON1_WAITWRC2
 150                 | BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
 151                 | BUSCON1_CMULT4, LTQ_EBU_BUSCON1);
 152
 153         ltq_ebu_w32(NAND_CON_NANDM | NAND_CON_CSMUX | NAND_CON_CS_P
 154                 | NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
 155                 | cs_flag, EBU_NAND_CON);
 156
 157         /* finish with a reset */
 158         xway_reset_chip(this);
 159
 160         return 0;
 161 }
 162
 163 static struct platform_nand_data xway_nand_data = {
 164         .chip = {
 165                 .nr_chips               = 1,
 166                 .chip_delay             = 30,
 167         },
 168         .ctrl = {
 169                 .probe          = xway_nand_probe,
 170                 .cmd_ctrl       = xway_cmd_ctrl,
 171                 .dev_ready      = xway_dev_ready,
 172                 .select_chip    = xway_select_chip,
 173                 .read_byte      = xway_read_byte,
 174         }
 175 };
 176
 177 /*
 178  * Try to find the node inside the DT. If it is available attach out
 179  * platform_nand_data
 180  */
 181 static int __init xway_register_nand(void)
 182 {
 183         struct device_node *node;
 184         struct platform_device *pdev;
 185
 186         node = of_find_compatible_node(NULL, NULL, "lantiq,nand-xway");
 187         if (!node)
 188                 return -ENOENT;
 189         pdev = of_find_device_by_node(node);
 190         if (!pdev)
 191                 return -EINVAL;
 192         pdev->dev.platform_data = &xway_nand_data;
 193         of_node_put(node);
 194         return 0;
 195 }
 196
 197 subsys_initcall(xway_register_nand);