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  *  Copyright © 2016 Hauke Mehrtens <hauke@hauke-m.de>
   8  */
   9
  10 #include <linux/mtd/nand.h>
  11 #include <linux/of_gpio.h>
  12 #include <linux/of_platform.h>
  13
  14 #include <lantiq_soc.h>
  15
  16 /* nand registers */
  17 #define EBU_ADDSEL1             0x24
  18 #define EBU_NAND_CON            0xB0
  19 #define EBU_NAND_WAIT           0xB4
  20 #define  NAND_WAIT_RD           BIT(0) /* NAND flash status output */
  21 #define  NAND_WAIT_WR_C         BIT(3) /* NAND Write/Read complete */
  22 #define EBU_NAND_ECC0           0xB8
  23 #define EBU_NAND_ECC_AC         0xBC
  24
  25 /*
  26  * nand commands
  27  * The pins of the NAND chip are selected based on the address bits of the
  28  * "register" read and write. There are no special registers, but an
  29  * address range and the lower address bits are used to activate the
  30  * correct line. For example when the bit (1 << 2) is set in the address
  31  * the ALE pin will be activated.
  32  */
  33 #define NAND_CMD_ALE            BIT(2) /* address latch enable */
  34 #define NAND_CMD_CLE            BIT(3) /* command latch enable */
  35 #define NAND_CMD_CS             BIT(4) /* chip select */
  36 #define NAND_CMD_SE             BIT(5) /* spare area access latch */
  37 #define NAND_CMD_WP             BIT(6) /* write protect */
  38 #define NAND_WRITE_CMD          (NAND_CMD_CS | NAND_CMD_CLE)
  39 #define NAND_WRITE_ADDR         (NAND_CMD_CS | NAND_CMD_ALE)
  40 #define NAND_WRITE_DATA         (NAND_CMD_CS)
  41 #define NAND_READ_DATA          (NAND_CMD_CS)
  42
  43 /* we need to tel the ebu which addr we mapped the nand to */
  44 #define ADDSEL1_MASK(x)         (x << 4)
  45 #define ADDSEL1_REGEN           1
  46
  47 /* we need to tell the EBU that we have nand attached and set it up properly */
  48 #define BUSCON1_SETUP           (1 << 22)
  49 #define BUSCON1_BCGEN_RES       (0x3 << 12)
  50 #define BUSCON1_WAITWRC2        (2 << 8)
  51 #define BUSCON1_WAITRDC2        (2 << 6)
  52 #define BUSCON1_HOLDC1          (1 << 4)
  53 #define BUSCON1_RECOVC1         (1 << 2)
  54 #define BUSCON1_CMULT4          1
  55
  56 #define NAND_CON_CE             (1 << 20)
  57 #define NAND_CON_OUT_CS1        (1 << 10)
  58 #define NAND_CON_IN_CS1         (1 << 8)
  59 #define NAND_CON_PRE_P          (1 << 7)
  60 #define NAND_CON_WP_P           (1 << 6)
  61 #define NAND_CON_SE_P           (1 << 5)
  62 #define NAND_CON_CS_P           (1 << 4)
  63 #define NAND_CON_CSMUX          (1 << 1)
  64 #define NAND_CON_NANDM          1
  65
  66 struct xway_nand_data {
  67         struct nand_chip        chip;
  68         unsigned long           csflags;
  69         void __iomem            *nandaddr;
  70 };
  71
  72 static u8 xway_readb(struct mtd_info *mtd, int op)
  73 {
  74         struct nand_chip *chip = mtd_to_nand(mtd);
  75         struct xway_nand_data *data = nand_get_controller_data(chip);
  76
  77         return readb(data->nandaddr + op);
  78 }
  79
  80 static void xway_writeb(struct mtd_info *mtd, int op, u8 value)
  81 {
  82         struct nand_chip *chip = mtd_to_nand(mtd);
  83         struct xway_nand_data *data = nand_get_controller_data(chip);
  84
  85         writeb(value, data->nandaddr + op);
  86 }
  87
  88 static void xway_select_chip(struct mtd_info *mtd, int select)
  89 {
  90         struct nand_chip *chip = mtd_to_nand(mtd);
  91         struct xway_nand_data *data = nand_get_controller_data(chip);
  92
  93         switch (select) {
  94         case -1:
  95                 ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
  96                 ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
  97                 spin_unlock_irqrestore(&ebu_lock, data->csflags);
  98                 break;
  99         case 0:
 100                 spin_lock_irqsave(&ebu_lock, data->csflags);
 101                 ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
 102                 ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
 103                 break;
 104         default:
 105                 BUG();
 106         }
 107 }
 108
 109 static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
 110 {
 111         if (cmd == NAND_CMD_NONE)
 112                 return;
 113
 114         if (ctrl & NAND_CLE)
 115                 xway_writeb(mtd, NAND_WRITE_CMD, cmd);
 116         else if (ctrl & NAND_ALE)
 117                 xway_writeb(mtd, NAND_WRITE_ADDR, cmd);
 118
 119         while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
 120                 ;
 121 }
 122
 123 static int xway_dev_ready(struct mtd_info *mtd)
 124 {
 125         return ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_RD;
 126 }
 127
 128 static unsigned char xway_read_byte(struct mtd_info *mtd)
 129 {
 130         return xway_readb(mtd, NAND_READ_DATA);
 131 }
 132
 133 static void xway_read_buf(struct mtd_info *mtd, u_char *buf, int len)
 134 {
 135         int i;
 136
 137         for (i = 0; i < len; i++)
 138                 buf[i] = xway_readb(mtd, NAND_WRITE_DATA);
 139 }
 140
 141 static void xway_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
 142 {
 143         int i;
 144
 145         for (i = 0; i < len; i++)
 146                 xway_writeb(mtd, NAND_WRITE_DATA, buf[i]);
 147 }
 148
 149 /*
 150  * Probe for the NAND device.
 151  */
 152 static int xway_nand_probe(struct platform_device *pdev)
 153 {
 154         struct xway_nand_data *data;
 155         struct mtd_info *mtd;
 156         struct resource *res;
 157         int err;
 158         u32 cs;
 159         u32 cs_flag = 0;
 160
 161         /* Allocate memory for the device structure (and zero it) */
 162         data = devm_kzalloc(&pdev->dev, sizeof(struct xway_nand_data),
 163                             GFP_KERNEL);
 164         if (!data)
 165                 return -ENOMEM;
 166
 167         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 168         data->nandaddr = devm_ioremap_resource(&pdev->dev, res);
 169         if (IS_ERR(data->nandaddr))
 170                 return PTR_ERR(data->nandaddr);
 171
 172         nand_set_flash_node(&data->chip, pdev->dev.of_node);
 173         mtd = nand_to_mtd(&data->chip);
 174         mtd->dev.parent = &pdev->dev;
 175
 176         data->chip.cmd_ctrl = xway_cmd_ctrl;
 177         data->chip.dev_ready = xway_dev_ready;
 178         data->chip.select_chip = xway_select_chip;
 179         data->chip.write_buf = xway_write_buf;
 180         data->chip.read_buf = xway_read_buf;
 181         data->chip.read_byte = xway_read_byte;
 182         data->chip.chip_delay = 30;
 183
 184         data->chip.ecc.mode = NAND_ECC_SOFT;
 185         data->chip.ecc.algo = NAND_ECC_HAMMING;
 186
 187         platform_set_drvdata(pdev, data);
 188         nand_set_controller_data(&data->chip, data);
 189
 190         /* load our CS from the DT. Either we find a valid 1 or default to 0 */
 191         err = of_property_read_u32(pdev->dev.of_node, "lantiq,cs", &cs);
 192         if (!err && cs == 1)
 193                 cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;
 194
 195         /* setup the EBU to run in NAND mode on our base addr */
 196         ltq_ebu_w32(CPHYSADDR(data->nandaddr)
 197                     | ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);
 198
 199         ltq_ebu_w32(BUSCON1_SETUP | BUSCON1_BCGEN_RES | BUSCON1_WAITWRC2
 200                     | BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
 201                     | BUSCON1_CMULT4, LTQ_EBU_BUSCON1);
 202
 203         ltq_ebu_w32(NAND_CON_NANDM | NAND_CON_CSMUX | NAND_CON_CS_P
 204                     | NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
 205                     | cs_flag, EBU_NAND_CON);
 206
 207         /* Scan to find existence of the device */
 208         err = nand_scan(mtd, 1);
 209         if (err)
 210                 return err;
 211
 212         err = mtd_device_register(mtd, NULL, 0);
 213         if (err)
 214                 nand_release(mtd);
 215
 216         return err;
 217 }
 218
 219 /*
 220  * Remove a NAND device.
 221  */
 222 static int xway_nand_remove(struct platform_device *pdev)
 223 {
 224         struct xway_nand_data *data = platform_get_drvdata(pdev);
 225
 226         nand_release(nand_to_mtd(&data->chip));
 227
 228         return 0;
 229 }
 230
 231 static const struct of_device_id xway_nand_match[] = {
 232         { .compatible = "lantiq,nand-xway" },
 233         {},
 234 };
 235
 236 static struct platform_driver xway_nand_driver = {
 237         .probe  = xway_nand_probe,
 238         .remove = xway_nand_remove,
 239         .driver = {
 240                 .name           = "lantiq,nand-xway",
 241                 .of_match_table = xway_nand_match,
 242         },
 243 };
 244
 245 builtin_platform_driver(xway_nand_driver);