target/linux/lantiq/patches-4.9/0018-MTD-nand-lots-of-xrx200-fixes.patch

   1 From 997a8965db8417266bea3fbdcfa3e5655a1b52fa Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Tue, 9 Sep 2014 23:12:15 +0200
   4 Subject: [PATCH 18/36] MTD: nand: lots of xrx200 fixes
   5
   6 Signed-off-by: John Crispin <blogic@openwrt.org>
   7 ---
   8  drivers/mtd/nand/xway_nand.c |   63 ++++++++++++++++++++++++++++++++++++++++++
   9  1 file changed, 63 insertions(+)
  10
  11 --- a/drivers/mtd/nand/xway_nand.c
  12 +++ b/drivers/mtd/nand/xway_nand.c
  13 @@ -63,6 +63,24 @@
  14  #define NAND_CON_CSMUX         (1 << 1)
  15  #define NAND_CON_NANDM         1
  16
  17 +#define DANUBE_PCI_REG32( addr )    (*(volatile u32 *)(addr))
  18 +#define PCI_CR_PR_OFFSET           (KSEG1+0x1E105400)
  19 +#define PCI_CR_PC_ARB              (PCI_CR_PR_OFFSET + 0x0080)
  20 +
  21 +/*
  22 + * req_mask provides a mechanism to prevent interference between
  23 + * nand and pci (probably only relevant for the BT Home Hub 2B).
  24 + * Setting it causes the corresponding pci req pins to be masked
  25 + * during nand access, and also moves ebu locking from the read/write
  26 + * functions to the chip select function to ensure that the whole
  27 + * operation runs with interrupts disabled.
  28 + * In addition it switches on some extra waiting in xway_cmd_ctrl().
  29 + * This seems to be necessary if the ebu_cs1 pin has open-drain disabled,
  30 + * which in turn seems to be necessary for the nor chip to be recognised
  31 + * reliably, on a board (Home Hub 2B again) which has both nor and nand.
  32 + */
  33 +static __be32 req_mask = 0;
  34 +
  35  struct xway_nand_data {
  36         struct nand_chip        chip;
  37         unsigned long           csflags;
  38 @@ -94,10 +112,22 @@ static void xway_select_chip(struct mtd_
  39         case -1:
  40                 ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
  41                 ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
  42 +
  43 +               if (req_mask) {
  44 +                       /* Unmask all external PCI request */
  45 +                       DANUBE_PCI_REG32(PCI_CR_PC_ARB) &= ~(req_mask << 16);
  46 +               }
  47 +
  48                 spin_unlock_irqrestore(&ebu_lock, data->csflags);
  49                 break;
  50         case 0:
  51                 spin_lock_irqsave(&ebu_lock, data->csflags);
  52 +
  53 +               if (req_mask) {
  54 +                       /* Mask all external PCI request */
  55 +                       DANUBE_PCI_REG32(PCI_CR_PC_ARB) |= (req_mask << 16);
  56 +               }
  57 +
  58                 ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
  59                 ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
  60                 break;
  61 @@ -108,6 +138,12 @@ static void xway_select_chip(struct mtd_
  62
  63  static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
  64  {
  65 +
  66 +       if (req_mask) {
  67 +               if (cmd != NAND_CMD_STATUS)
  68 +                       ltq_ebu_w32(0, EBU_NAND_WAIT); /* Clear nand ready */
  69 +       }
  70 +
  71         if (cmd == NAND_CMD_NONE)
  72                 return;
  73
  74 @@ -118,6 +154,24 @@ static void xway_cmd_ctrl(struct mtd_inf
  75
  76         while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
  77                 ;
  78 +
  79 +       if (req_mask) {
  80 +              /*
  81 +               * program and erase have their own busy handlers
  82 +               * status and sequential in needs no delay
  83 +               */
  84 +               switch (cmd) {
  85 +                       case NAND_CMD_ERASE1:
  86 +                       case NAND_CMD_SEQIN:
  87 +                       case NAND_CMD_STATUS:
  88 +                       case NAND_CMD_READID:
  89 +                       return;
  90 +               }
  91 +
  92 +               /* wait until command is processed */
  93 +               while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_RD) == 0)
  94 +                       ;
  95 +       }
  96  }
  97
  98  static int xway_dev_ready(struct mtd_info *mtd)
  99 @@ -157,6 +211,7 @@ static int xway_nand_probe(struct platfo
 100         int err;
 101         u32 cs;
 102         u32 cs_flag = 0;
 103 +       const __be32 *req_mask_ptr;
 104
 105         /* Allocate memory for the device structure (and zero it) */
 106         data = devm_kzalloc(&pdev->dev, sizeof(struct xway_nand_data),
 107 @@ -192,6 +247,15 @@ static int xway_nand_probe(struct platfo
 108         if (!err && cs == 1)
 109                 cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;
 110
 111 +       req_mask_ptr = of_get_property(pdev->dev.of_node,
 112 +                                       "req-mask", NULL);
 113 +
 114 +       /*
 115 +        * Load the PCI req lines to mask from the device tree. If the
 116 +        * property is not present, setting req_mask to 0 disables masking.
 117 +        */
 118 +       req_mask = (req_mask_ptr ? *req_mask_ptr : 0);
 119 +
 120         /* setup the EBU to run in NAND mode on our base addr */
 121         ltq_ebu_w32(CPHYSADDR(data->nandaddr)
 122                     | ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);