target/linux/generic/patches-4.4/081-spi-bcm53xx-add-spi_flash_read-callback-for-MMIO-bas.patch

   1 From a7b221d8f0d75511c5f959584712a5dd35f88a86 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
   3 Date: Mon, 18 Apr 2016 14:39:30 +0200
   4 Subject: [PATCH] spi: bcm53xx: add spi_flash_read callback for MMIO-based
   5  reads
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 This implements more efficient reads of SPI-attached flash content.
  11
  12 Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
  13 Signed-off-by: Mark Brown <broonie@kernel.org>
  14 ---
  15
  16 --- a/drivers/spi/spi-bcm53xx.c
  17 +++ b/drivers/spi/spi-bcm53xx.c
  18 @@ -10,6 +10,7 @@
  19  #include "spi-bcm53xx.h"
  20
  21  #define BCM53XXSPI_MAX_SPI_BAUD        13500000        /* 216 MHz? */
  22 +#define BCM53XXSPI_FLASH_WINDOW        SZ_32M
  23
  24  /* The longest observed required wait was 19 ms */
  25  #define BCM53XXSPI_SPE_TIMEOUT_MS      80
  26 @@ -17,8 +18,10 @@
  27  struct bcm53xxspi {
  28         struct bcma_device *core;
  29         struct spi_master *master;
  30 +       void __iomem *mmio_base;
  31
  32         size_t read_offset;
  33 +       bool bspi;                              /* Boot SPI mode with memory mapping */
  34  };
  35
  36  static inline u32 bcm53xxspi_read(struct bcm53xxspi *b53spi, u16 offset)
  37 @@ -32,6 +35,50 @@ static inline void bcm53xxspi_write(struct bcm53xxspi *b53spi, u16 offset,
  38         bcma_write32(b53spi->core, offset, value);
  39  }
  40
  41 +static void bcm53xxspi_disable_bspi(struct bcm53xxspi *b53spi)
  42 +{
  43 +       struct device *dev = &b53spi->core->dev;
  44 +       unsigned long deadline;
  45 +       u32 tmp;
  46 +
  47 +       if (!b53spi->bspi)
  48 +               return;
  49 +
  50 +       tmp = bcm53xxspi_read(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL);
  51 +       if (tmp & 0x1)
  52 +               return;
  53 +
  54 +       deadline = jiffies + usecs_to_jiffies(200);
  55 +       do {
  56 +               tmp = bcm53xxspi_read(b53spi, B53SPI_BSPI_BUSY_STATUS);
  57 +               if (!(tmp & 0x1)) {
  58 +                       bcm53xxspi_write(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL,
  59 +                                        0x1);
  60 +                       ndelay(200);
  61 +                       b53spi->bspi = false;
  62 +                       return;
  63 +               }
  64 +               udelay(1);
  65 +       } while (!time_after_eq(jiffies, deadline));
  66 +
  67 +       dev_warn(dev, "Timeout disabling BSPI\n");
  68 +}
  69 +
  70 +static void bcm53xxspi_enable_bspi(struct bcm53xxspi *b53spi)
  71 +{
  72 +       u32 tmp;
  73 +
  74 +       if (b53spi->bspi)
  75 +               return;
  76 +
  77 +       tmp = bcm53xxspi_read(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL);
  78 +       if (!(tmp & 0x1))
  79 +               return;
  80 +
  81 +       bcm53xxspi_write(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL, 0x0);
  82 +       b53spi->bspi = true;
  83 +}
  84 +
  85  static inline unsigned int bcm53xxspi_calc_timeout(size_t len)
  86  {
  87         /* Do some magic calculation based on length and buad. Add 10% and 1. */
  88 @@ -176,6 +223,8 @@ static int bcm53xxspi_transfer_one(struct spi_master *master,
  89         u8 *buf;
  90         size_t left;
  91
  92 +       bcm53xxspi_disable_bspi(b53spi);
  93 +
  94         if (t->tx_buf) {
  95                 buf = (u8 *)t->tx_buf;
  96                 left = t->len;
  97 @@ -206,6 +255,22 @@ static int bcm53xxspi_transfer_one(struct spi_master *master,
  98         return 0;
  99  }
 100
 101 +static int bcm53xxspi_flash_read(struct spi_device *spi,
 102 +                                struct spi_flash_read_message *msg)
 103 +{
 104 +       struct bcm53xxspi *b53spi = spi_master_get_devdata(spi->master);
 105 +       int ret = 0;
 106 +
 107 +       if (msg->from + msg->len > BCM53XXSPI_FLASH_WINDOW)
 108 +               return -EINVAL;
 109 +
 110 +       bcm53xxspi_enable_bspi(b53spi);
 111 +       memcpy_fromio(msg->buf, b53spi->mmio_base + msg->from, msg->len);
 112 +       msg->retlen = msg->len;
 113 +
 114 +       return ret;
 115 +}
 116 +
 117  /**************************************************
 118   * BCMA
 119   **************************************************/
 120 @@ -222,6 +287,7 @@ MODULE_DEVICE_TABLE(bcma, bcm53xxspi_bcma_tbl);
 121
 122  static int bcm53xxspi_bcma_probe(struct bcma_device *core)
 123  {
 124 +       struct device *dev = &core->dev;
 125         struct bcm53xxspi *b53spi;
 126         struct spi_master *master;
 127         int err;
 128 @@ -231,7 +297,7 @@ static int bcm53xxspi_bcma_probe(struct bcma_device *core)
 129                 return -ENOTSUPP;
 130         }
 131
 132 -       master = spi_alloc_master(&core->dev, sizeof(*b53spi));
 133 +       master = spi_alloc_master(dev, sizeof(*b53spi));
 134         if (!master)
 135                 return -ENOMEM;
 136
 137 @@ -239,11 +305,19 @@ static int bcm53xxspi_bcma_probe(struct bcma_device *core)
 138         b53spi->master = master;
 139         b53spi->core = core;
 140
 141 +       if (core->addr_s[0])
 142 +               b53spi->mmio_base = devm_ioremap(dev, core->addr_s[0],
 143 +                                                BCM53XXSPI_FLASH_WINDOW);
 144 +       b53spi->bspi = true;
 145 +       bcm53xxspi_disable_bspi(b53spi);
 146 +
 147         master->transfer_one = bcm53xxspi_transfer_one;
 148 +       if (b53spi->mmio_base)
 149 +               master->spi_flash_read = bcm53xxspi_flash_read;
 150
 151         bcma_set_drvdata(core, b53spi);
 152
 153 -       err = devm_spi_register_master(&core->dev, master);
 154 +       err = devm_spi_register_master(dev, master);
 155         if (err) {
 156                 spi_master_put(master);
 157                 bcma_set_drvdata(core, NULL);