target/linux/xburst/patches-2.6.35/400-spi-gpio-3wire.patch

   1 From 62b6a295d39417293adcc81dc36b7edc56546814 Mon Sep 17 00:00:00 2001
   2 From: Lars-Peter Clausen <lars@metafoo.de>
   3 Date: Sat, 24 Apr 2010 12:23:01 +0200
   4 Subject: [PATCH] gpio spi 3wire
   5
   6 ---
   7  drivers/spi/spi_bitbang.c       |    2 +
   8  drivers/spi/spi_gpio.c          |   60 ++++++++++++++++++++++++++------------
   9  include/linux/spi/spi_bitbang.h |    2 +
  10  3 files changed, 45 insertions(+), 19 deletions(-)
  11
  12 --- a/drivers/spi/spi_bitbang.c
  13 +++ b/drivers/spi/spi_bitbang.c
  14 @@ -335,6 +335,8 @@ static void bitbang_work(struct work_str
  15                                  */
  16                                 if (!m->is_dma_mapped)
  17                                         t->rx_dma = t->tx_dma = 0;
  18 +                               if ((spi->mode & SPI_3WIRE) && bitbang->set_direction)
  19 +                                       bitbang->set_direction(spi, t->tx_buf != NULL);
  20                                 status = bitbang->txrx_bufs(spi, t);
  21                         }
  22                         if (status > 0)
  23 --- a/drivers/spi/spi_gpio.c
  24 +++ b/drivers/spi/spi_gpio.c
  25 @@ -46,6 +46,8 @@ struct spi_gpio {
  26         struct spi_bitbang              bitbang;
  27         struct spi_gpio_platform_data   pdata;
  28         struct platform_device          *pdev;
  29 +
  30 +       int miso_pin;
  31  };
  32
  33  /*----------------------------------------------------------------------*/
  34 @@ -91,19 +93,16 @@ struct spi_gpio {
  35
  36  /*----------------------------------------------------------------------*/
  37
  38 -static inline const struct spi_gpio_platform_data * __pure
  39 -spi_to_pdata(const struct spi_device *spi)
  40 +static inline const struct spi_gpio * __pure
  41 +spi_to_spi_gpio(const struct spi_device *spi)
  42  {
  43         const struct spi_bitbang        *bang;
  44 -       const struct spi_gpio           *spi_gpio;
  45
  46         bang = spi_master_get_devdata(spi->master);
  47 -       spi_gpio = container_of(bang, struct spi_gpio, bitbang);
  48 -       return &spi_gpio->pdata;
  49 +       return container_of(bang, struct spi_gpio, bitbang);
  50  }
  51
  52 -/* this is #defined to avoid unused-variable warnings when inlining */
  53 -#define pdata          spi_to_pdata(spi)
  54 +#define pdata &(spi_to_spi_gpio(spi)->pdata)
  55
  56  static inline void setsck(const struct spi_device *spi, int is_on)
  57  {
  58 @@ -117,10 +116,9 @@ static inline void setmosi(const struct
  59
  60  static inline int getmiso(const struct spi_device *spi)
  61  {
  62 -       return !!gpio_get_value(SPI_MISO_GPIO);
  63 +       return !!gpio_get_value(spi_to_spi_gpio(spi)->miso_pin);
  64  }
  65
  66 -#undef pdata
  67
  68  /*
  69   * NOTE:  to clock "as fast as we can", set spi_device.max_speed_hz
  70 @@ -183,10 +181,16 @@ static u32 spi_gpio_txrx_word_mode3(stru
  71  static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
  72  {
  73         unsigned long cs = (unsigned long) spi->controller_data;
  74 +       struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
  75
  76         /* set initial clock polarity */
  77 -       if (is_active)
  78 +       if (is_active) {
  79                 setsck(spi, spi->mode & SPI_CPOL);
  80 +               if (spi->mode & SPI_3WIRE)
  81 +                       spi_gpio->miso_pin = SPI_MOSI_GPIO;
  82 +               else
  83 +                       spi_gpio->miso_pin = SPI_MISO_GPIO;
  84 +       }
  85
  86         if (cs != SPI_GPIO_NO_CHIPSELECT) {
  87                 /* SPI is normally active-low */
  88 @@ -202,6 +206,9 @@ static int spi_gpio_setup(struct spi_dev
  89         if (spi->bits_per_word > 32)
  90                 return -EINVAL;
  91
  92 +       if (!(spi->mode & SPI_3WIRE) && !gpio_is_valid(SPI_MISO_GPIO))
  93 +               return -EINVAL;
  94 +
  95         if (!spi->controller_state) {
  96                 if (cs != SPI_GPIO_NO_CHIPSELECT) {
  97                         status = gpio_request(cs, dev_name(&spi->dev));
  98 @@ -219,6 +226,16 @@ static int spi_gpio_setup(struct spi_dev
  99         return status;
 100  }
 101
 102 +static void spi_gpio_set_direction(struct spi_device *spi, bool is_tx)
 103 +{
 104 +       if (is_tx)
 105 +               gpio_direction_output(SPI_MISO_GPIO, 0);
 106 +       else
 107 +               gpio_direction_input(SPI_MISO_GPIO);
 108 +}
 109 +
 110 +#undef pdata
 111 +
 112  static void spi_gpio_cleanup(struct spi_device *spi)
 113  {
 114         unsigned long   cs = (unsigned long) spi->controller_data;
 115 @@ -253,18 +270,20 @@ spi_gpio_request(struct spi_gpio_platfor
 116         if (value)
 117                 goto done;
 118
 119 -       value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
 120 +       value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
 121         if (value)
 122                 goto free_mosi;
 123
 124 -       value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
 125 -       if (value)
 126 -               goto free_miso;
 127 +       if (gpio_is_valid(SPI_MISO_GPIO)) {
 128 +               value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
 129 +               if (value)
 130 +                       goto free_sck;
 131 +       }
 132
 133         goto done;
 134
 135 -free_miso:
 136 -       gpio_free(SPI_MISO_GPIO);
 137 +free_sck:
 138 +       gpio_free(SPI_SCK_GPIO);
 139  free_mosi:
 140         gpio_free(SPI_MOSI_GPIO);
 141  done:
 142 @@ -312,13 +331,15 @@ static int __devinit spi_gpio_probe(stru
 143         spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;
 144         spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;
 145         spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer;
 146 -       spi_gpio->bitbang.flags = SPI_CS_HIGH;
 147 +       spi_gpio->bitbang.set_direction = spi_gpio_set_direction;
 148 +       spi_gpio->bitbang.flags = SPI_CS_HIGH | SPI_3WIRE;
 149
 150         status = spi_bitbang_start(&spi_gpio->bitbang);
 151         if (status < 0) {
 152                 spi_master_put(spi_gpio->bitbang.master);
 153  gpio_free:
 154 -               gpio_free(SPI_MISO_GPIO);
 155 +               if (gpio_is_valid(SPI_MOSI_GPIO))
 156 +                       gpio_free(SPI_MISO_GPIO);
 157                 gpio_free(SPI_MOSI_GPIO);
 158                 gpio_free(SPI_SCK_GPIO);
 159                 spi_master_put(master);
 160 @@ -342,7 +363,8 @@ static int __devexit spi_gpio_remove(str
 161
 162         platform_set_drvdata(pdev, NULL);
 163
 164 -       gpio_free(SPI_MISO_GPIO);
 165 +       if (gpio_is_valid(SPI_MISO_GPIO))
 166 +               gpio_free(SPI_MISO_GPIO);
 167         gpio_free(SPI_MOSI_GPIO);
 168         gpio_free(SPI_SCK_GPIO);
 169
 170 --- a/include/linux/spi/spi_bitbang.h
 171 +++ b/include/linux/spi/spi_bitbang.h
 172 @@ -34,6 +34,8 @@ struct spi_bitbang {
 173         u32     (*txrx_word[4])(struct spi_device *spi,
 174                         unsigned nsecs,
 175                         u32 word, u8 bits);
 176 +
 177 +       void (*set_direction)(struct spi_device *, bool is_tx);
 178  };
 179
 180  /* you can call these default bitbang->master methods from your custom