target/linux/xburst/patches-2.6.34/400-spi-gpio-3wire.patch

   1 From 4cee37dd779deeb01f263995e8bd5e7b8457965b 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 diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c
  13 index 5265330..2bec91c 100644
  14 --- a/drivers/spi/spi_bitbang.c
  15 +++ b/drivers/spi/spi_bitbang.c
  16 @@ -335,6 +335,8 @@ static void bitbang_work(struct work_struct *work)
  17                                  */
  18                                 if (!m->is_dma_mapped)
  19                                         t->rx_dma = t->tx_dma = 0;
  20 +                               if ((spi->mode & SPI_3WIRE) && bitbang->set_direction)
  21 +                                       bitbang->set_direction(spi, t->tx_buf != NULL);
  22                                 status = bitbang->txrx_bufs(spi, t);
  23                         }
  24                         if (status > 0)
  25 diff --git a/drivers/spi/spi_gpio.c b/drivers/spi/spi_gpio.c
  26 index 26bd03e..ca769b8 100644
  27 --- a/drivers/spi/spi_gpio.c
  28 +++ b/drivers/spi/spi_gpio.c
  29 @@ -45,6 +45,8 @@ struct spi_gpio {
  30         struct spi_bitbang              bitbang;
  31         struct spi_gpio_platform_data   pdata;
  32         struct platform_device          *pdev;
  33 +
  34 +       int miso_pin;
  35  };
  36
  37  /*----------------------------------------------------------------------*/
  38 @@ -88,19 +90,16 @@ struct spi_gpio {
  39
  40  /*----------------------------------------------------------------------*/
  41
  42 -static inline const struct spi_gpio_platform_data * __pure
  43 -spi_to_pdata(const struct spi_device *spi)
  44 +static inline const struct spi_gpio * __pure
  45 +spi_to_spi_gpio(const struct spi_device *spi)
  46  {
  47         const struct spi_bitbang        *bang;
  48 -       const struct spi_gpio           *spi_gpio;
  49
  50         bang = spi_master_get_devdata(spi->master);
  51 -       spi_gpio = container_of(bang, struct spi_gpio, bitbang);
  52 -       return &spi_gpio->pdata;
  53 +       return container_of(bang, struct spi_gpio, bitbang);
  54  }
  55
  56 -/* this is #defined to avoid unused-variable warnings when inlining */
  57 -#define pdata          spi_to_pdata(spi)
  58 +#define pdata &(spi_to_spi_gpio(spi)->pdata)
  59
  60  static inline void setsck(const struct spi_device *spi, int is_on)
  61  {
  62 @@ -114,10 +113,9 @@ static inline void setmosi(const struct spi_device *spi, int is_on)
  63
  64  static inline int getmiso(const struct spi_device *spi)
  65  {
  66 -       return !!gpio_get_value(SPI_MISO_GPIO);
  67 +       return !!gpio_get_value(spi_to_spi_gpio(spi)->miso_pin);
  68  }
  69
  70 -#undef pdata
  71
  72  /*
  73   * NOTE:  this clocks "as fast as we can".  It "should" be a function of the
  74 @@ -173,10 +171,16 @@ static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi,
  75  static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
  76  {
  77         unsigned long cs = (unsigned long) spi->controller_data;
  78 +       struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
  79
  80         /* set initial clock polarity */
  81 -       if (is_active)
  82 +       if (is_active) {
  83                 setsck(spi, spi->mode & SPI_CPOL);
  84 +               if (spi->mode & SPI_3WIRE)
  85 +                       spi_gpio->miso_pin = SPI_MOSI_GPIO;
  86 +               else
  87 +                       spi_gpio->miso_pin = SPI_MISO_GPIO;
  88 +       }
  89
  90         if (cs != SPI_GPIO_NO_CHIPSELECT) {
  91                 /* SPI is normally active-low */
  92 @@ -192,6 +196,9 @@ static int spi_gpio_setup(struct spi_device *spi)
  93         if (spi->bits_per_word > 32)
  94                 return -EINVAL;
  95
  96 +       if (!(spi->mode & SPI_3WIRE) && !gpio_is_valid(SPI_MISO_GPIO))
  97 +               return -EINVAL;
  98 +
  99         if (!spi->controller_state) {
 100                 if (cs != SPI_GPIO_NO_CHIPSELECT) {
 101                         status = gpio_request(cs, dev_name(&spi->dev));
 102 @@ -209,6 +216,16 @@ static int spi_gpio_setup(struct spi_device *spi)
 103         return status;
 104  }
 105
 106 +static void spi_gpio_set_direction(struct spi_device *spi, bool is_tx)
 107 +{
 108 +       if (is_tx)
 109 +               gpio_direction_output(SPI_MISO_GPIO, 0);
 110 +       else
 111 +               gpio_direction_input(SPI_MISO_GPIO);
 112 +}
 113 +
 114 +#undef pdata
 115 +
 116  static void spi_gpio_cleanup(struct spi_device *spi)
 117  {
 118         unsigned long   cs = (unsigned long) spi->controller_data;
 119 @@ -243,18 +260,20 @@ spi_gpio_request(struct spi_gpio_platform_data *pdata, const char *label)
 120         if (value)
 121                 goto done;
 122
 123 -       value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
 124 +       value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
 125         if (value)
 126                 goto free_mosi;
 127
 128 -       value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
 129 -       if (value)
 130 -               goto free_miso;
 131 +       if (gpio_is_valid(SPI_MISO_GPIO)) {
 132 +               value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
 133 +               if (value)
 134 +                       goto free_sck;
 135 +       }
 136
 137         goto done;
 138
 139 -free_miso:
 140 -       gpio_free(SPI_MISO_GPIO);
 141 +free_sck:
 142 +       gpio_free(SPI_SCK_GPIO);
 143  free_mosi:
 144         gpio_free(SPI_MOSI_GPIO);
 145  done:
 146 @@ -302,13 +321,15 @@ static int __init spi_gpio_probe(struct platform_device *pdev)
 147         spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;
 148         spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;
 149         spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer;
 150 -       spi_gpio->bitbang.flags = SPI_CS_HIGH;
 151 +       spi_gpio->bitbang.set_direction = spi_gpio_set_direction;
 152 +       spi_gpio->bitbang.flags = SPI_CS_HIGH | SPI_3WIRE;
 153
 154         status = spi_bitbang_start(&spi_gpio->bitbang);
 155         if (status < 0) {
 156                 spi_master_put(spi_gpio->bitbang.master);
 157  gpio_free:
 158 -               gpio_free(SPI_MISO_GPIO);
 159 +               if (gpio_is_valid(SPI_MOSI_GPIO))
 160 +                       gpio_free(SPI_MISO_GPIO);
 161                 gpio_free(SPI_MOSI_GPIO);
 162                 gpio_free(SPI_SCK_GPIO);
 163                 spi_master_put(master);
 164 @@ -332,7 +353,8 @@ static int __exit spi_gpio_remove(struct platform_device *pdev)
 165
 166         platform_set_drvdata(pdev, NULL);
 167
 168 -       gpio_free(SPI_MISO_GPIO);
 169 +       if (gpio_is_valid(SPI_MISO_GPIO))
 170 +               gpio_free(SPI_MISO_GPIO);
 171         gpio_free(SPI_MOSI_GPIO);
 172         gpio_free(SPI_SCK_GPIO);
 173
 174 diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h
 175 index 3274c50..0a466c9 100644
 176 --- a/include/linux/spi/spi_bitbang.h
 177 +++ b/include/linux/spi/spi_bitbang.h
 178 @@ -52,6 +52,8 @@ struct spi_bitbang {
 179         u32     (*txrx_word[4])(struct spi_device *spi,
 180                         unsigned nsecs,
 181                         u32 word, u8 bits);
 182 +
 183 +       void (*set_direction)(struct spi_device *, bool is_tx);
 184  };
 185
 186  /* you can call these default bitbang->master methods from your custom
 187 --
 188 1.5.6.5
 189