drivers/mtd/nand/raw/xway_nand.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *
   4  *  Copyright © 2012 John Crispin <john@phrozen.org>
   5  *  Copyright © 2016 Hauke Mehrtens <hauke@hauke-m.de>
   6  */
   7
   8 #include <linux/mtd/rawnand.h>
   9 #include <linux/of_gpio.h>
  10 #include <linux/of_platform.h>
  11
  12 #include <lantiq_soc.h>
  13
  14 /* nand registers */
  15 #define EBU_ADDSEL1             0x24
  16 #define EBU_NAND_CON            0xB0
  17 #define EBU_NAND_WAIT           0xB4
  18 #define  NAND_WAIT_RD           BIT(0) /* NAND flash status output */
  19 #define  NAND_WAIT_WR_C         BIT(3) /* NAND Write/Read complete */
  20 #define EBU_NAND_ECC0           0xB8
  21 #define EBU_NAND_ECC_AC         0xBC
  22
  23 /*
  24  * nand commands
  25  * The pins of the NAND chip are selected based on the address bits of the
  26  * "register" read and write. There are no special registers, but an
  27  * address range and the lower address bits are used to activate the
  28  * correct line. For example when the bit (1 << 2) is set in the address
  29  * the ALE pin will be activated.
  30  */
  31 #define NAND_CMD_ALE            BIT(2) /* address latch enable */
  32 #define NAND_CMD_CLE            BIT(3) /* command latch enable */
  33 #define NAND_CMD_CS             BIT(4) /* chip select */
  34 #define NAND_CMD_SE             BIT(5) /* spare area access latch */
  35 #define NAND_CMD_WP             BIT(6) /* write protect */
  36 #define NAND_WRITE_CMD          (NAND_CMD_CS | NAND_CMD_CLE)
  37 #define NAND_WRITE_ADDR         (NAND_CMD_CS | NAND_CMD_ALE)
  38 #define NAND_WRITE_DATA         (NAND_CMD_CS)
  39 #define NAND_READ_DATA          (NAND_CMD_CS)
  40
  41 /* we need to tel the ebu which addr we mapped the nand to */
  42 #define ADDSEL1_MASK(x)         (x << 4)
  43 #define ADDSEL1_REGEN           1
  44
  45 /* we need to tell the EBU that we have nand attached and set it up properly */
  46 #define BUSCON1_SETUP           (1 << 22)
  47 #define BUSCON1_BCGEN_RES       (0x3 << 12)
  48 #define BUSCON1_WAITWRC2        (2 << 8)
  49 #define BUSCON1_WAITRDC2        (2 << 6)
  50 #define BUSCON1_HOLDC1          (1 << 4)
  51 #define BUSCON1_RECOVC1         (1 << 2)
  52 #define BUSCON1_CMULT4          1
  53
  54 #define NAND_CON_CE             (1 << 20)
  55 #define NAND_CON_OUT_CS1        (1 << 10)
  56 #define NAND_CON_IN_CS1         (1 << 8)
  57 #define NAND_CON_PRE_P          (1 << 7)
  58 #define NAND_CON_WP_P           (1 << 6)
  59 #define NAND_CON_SE_P           (1 << 5)
  60 #define NAND_CON_CS_P           (1 << 4)
  61 #define NAND_CON_CSMUX          (1 << 1)
  62 #define NAND_CON_NANDM          1
  63
  64 struct xway_nand_data {
  65         struct nand_chip        chip;
  66         unsigned long           csflags;
  67         void __iomem            *nandaddr;
  68 };
  69
  70 static u8 xway_readb(struct mtd_info *mtd, int op)
  71 {
  72         struct nand_chip *chip = mtd_to_nand(mtd);
  73         struct xway_nand_data *data = nand_get_controller_data(chip);
  74
  75         return readb(data->nandaddr + op);
  76 }
  77
  78 static void xway_writeb(struct mtd_info *mtd, int op, u8 value)
  79 {
  80         struct nand_chip *chip = mtd_to_nand(mtd);
  81         struct xway_nand_data *data = nand_get_controller_data(chip);
  82
  83         writeb(value, data->nandaddr + op);
  84 }
  85
  86 static void xway_select_chip(struct nand_chip *chip, int select)
  87 {
  88         struct xway_nand_data *data = nand_get_controller_data(chip);
  89
  90         switch (select) {
  91         case -1:
  92                 ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
  93                 ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
  94                 spin_unlock_irqrestore(&ebu_lock, data->csflags);
  95                 break;
  96         case 0:
  97                 spin_lock_irqsave(&ebu_lock, data->csflags);
  98                 ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
  99                 ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
 100                 break;
 101         default:
 102                 BUG();
 103         }
 104 }
 105
 106 static void xway_cmd_ctrl(struct nand_chip *chip, int cmd, unsigned int ctrl)
 107 {
 108         struct mtd_info *mtd = nand_to_mtd(chip);
 109
 110         if (cmd == NAND_CMD_NONE)
 111                 return;
 112
 113         if (ctrl & NAND_CLE)
 114                 xway_writeb(mtd, NAND_WRITE_CMD, cmd);
 115         else if (ctrl & NAND_ALE)
 116                 xway_writeb(mtd, NAND_WRITE_ADDR, cmd);
 117
 118         while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
 119                 ;
 120 }
 121
 122 static int xway_dev_ready(struct nand_chip *chip)
 123 {
 124         return ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_RD;
 125 }
 126
 127 static unsigned char xway_read_byte(struct nand_chip *chip)
 128 {
 129         return xway_readb(nand_to_mtd(chip), NAND_READ_DATA);
 130 }
 131
 132 static void xway_read_buf(struct nand_chip *chip, u_char *buf, int len)
 133 {
 134         int i;
 135
 136         for (i = 0; i < len; i++)
 137                 buf[i] = xway_readb(nand_to_mtd(chip), NAND_WRITE_DATA);
 138 }
 139
 140 static void xway_write_buf(struct nand_chip *chip, const u_char *buf, int len)
 141 {
 142         int i;
 143
 144         for (i = 0; i < len; i++)
 145                 xway_writeb(nand_to_mtd(chip), NAND_WRITE_DATA, buf[i]);
 146 }
 147
 148 /*
 149  * Probe for the NAND device.
 150  */
 151 static int xway_nand_probe(struct platform_device *pdev)
 152 {
 153         struct xway_nand_data *data;
 154         struct mtd_info *mtd;
 155         struct resource *res;
 156         int err;
 157         u32 cs;
 158         u32 cs_flag = 0;
 159
 160         /* Allocate memory for the device structure (and zero it) */
 161         data = devm_kzalloc(&pdev->dev, sizeof(struct xway_nand_data),
 162                             GFP_KERNEL);
 163         if (!data)
 164                 return -ENOMEM;
 165
 166         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 167         data->nandaddr = devm_ioremap_resource(&pdev->dev, res);
 168         if (IS_ERR(data->nandaddr))
 169                 return PTR_ERR(data->nandaddr);
 170
 171         nand_set_flash_node(&data->chip, pdev->dev.of_node);
 172         mtd = nand_to_mtd(&data->chip);
 173         mtd->dev.parent = &pdev->dev;
 174
 175         data->chip.legacy.cmd_ctrl = xway_cmd_ctrl;
 176         data->chip.legacy.dev_ready = xway_dev_ready;
 177         data->chip.legacy.select_chip = xway_select_chip;
 178         data->chip.legacy.write_buf = xway_write_buf;
 179         data->chip.legacy.read_buf = xway_read_buf;
 180         data->chip.legacy.read_byte = xway_read_byte;
 181         data->chip.legacy.chip_delay = 30;
 182
 183         data->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
 184         data->chip.ecc.algo = NAND_ECC_ALGO_HAMMING;
 185
 186         platform_set_drvdata(pdev, data);
 187         nand_set_controller_data(&data->chip, data);
 188
 189         /* load our CS from the DT. Either we find a valid 1 or default to 0 */
 190         err = of_property_read_u32(pdev->dev.of_node, "lantiq,cs", &cs);
 191         if (!err && cs == 1)
 192                 cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;
 193
 194         /* setup the EBU to run in NAND mode on our base addr */
 195         ltq_ebu_w32(CPHYSADDR(data->nandaddr)
 196                     | ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);
 197
 198         ltq_ebu_w32(BUSCON1_SETUP | BUSCON1_BCGEN_RES | BUSCON1_WAITWRC2
 199                     | BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
 200                     | BUSCON1_CMULT4, LTQ_EBU_BUSCON1);
 201
 202         ltq_ebu_w32(NAND_CON_NANDM | NAND_CON_CSMUX | NAND_CON_CS_P
 203                     | NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
 204                     | cs_flag, EBU_NAND_CON);
 205
 206         /* Scan to find existence of the device */
 207         err = nand_scan(&data->chip, 1);
 208         if (err)
 209                 return err;
 210
 211         err = mtd_device_register(mtd, NULL, 0);
 212         if (err)
 213                 nand_cleanup(&data->chip);
 214
 215         return err;
 216 }
 217
 218 /*
 219  * Remove a NAND device.
 220  */
 221 static int xway_nand_remove(struct platform_device *pdev)
 222 {
 223         struct xway_nand_data *data = platform_get_drvdata(pdev);
 224         struct nand_chip *chip = &data->chip;
 225         int ret;
 226
 227         ret = mtd_device_unregister(nand_to_mtd(chip));
 228         WARN_ON(ret);
 229         nand_cleanup(chip);
 230
 231         return 0;
 232 }
 233
 234 static const struct of_device_id xway_nand_match[] = {
 235         { .compatible = "lantiq,nand-xway" },
 236         {},
 237 };
 238
 239 static struct platform_driver xway_nand_driver = {
 240         .probe  = xway_nand_probe,
 241         .remove = xway_nand_remove,
 242         .driver = {
 243                 .name           = "lantiq,nand-xway",
 244                 .of_match_table = xway_nand_match,
 245         },
 246 };
 247
 248 builtin_platform_driver(xway_nand_driver);