target/linux/brcm63xx/patches-3.18/001-spi-spi-gpio-Add-dt-support-for-a-single-device-with.patch

   1 From d1d81802522ade84128a2c66c0d500e372474dca Mon Sep 17 00:00:00 2001
   2 From: Torsten Fleischer <torfl6749@gmail.com>
   3 Date: Mon, 3 Nov 2014 17:17:55 +0100
   4 Subject: [PATCH] spi: spi-gpio: Add dt support for a single device with no
   5  chip select
   6
   7 In order to describe a single slave device that has no chip select line
   8 the 'num-chipselects' property has to be <0> and the 'cs-gpios' property
   9 doesn't need to be set.
  10
  11 Signed-off-by: Torsten Fleischer <torfl6749@gmail.com>
  12 Signed-off-by: Mark Brown <broonie@kernel.org>
  13 ---
  14  Documentation/devicetree/bindings/spi/spi-gpio.txt |  6 ++++--
  15  drivers/spi/spi-gpio.c                             | 21 +++++++++++++++------
  16  2 files changed, 19 insertions(+), 8 deletions(-)
  17
  18 --- a/Documentation/devicetree/bindings/spi/spi-gpio.txt
  19 +++ b/Documentation/devicetree/bindings/spi/spi-gpio.txt
  20 @@ -8,8 +8,10 @@ Required properties:
  21   - gpio-sck: GPIO spec for the SCK line to use
  22   - gpio-miso: GPIO spec for the MISO line to use
  23   - gpio-mosi: GPIO spec for the MOSI line to use
  24 - - cs-gpios: GPIOs to use for chipselect lines
  25 - - num-chipselects: number of chipselect lines
  26 + - cs-gpios: GPIOs to use for chipselect lines.
  27 +             Not needed if num-chipselects = <0>.
  28 + - num-chipselects: Number of chipselect lines. Should be <0> if a single device
  29 +                    with no chip select is connected.
  30
  31  Example:
  32
  33 --- a/drivers/spi/spi-gpio.c
  34 +++ b/drivers/spi/spi-gpio.c
  35 @@ -424,6 +424,7 @@ static int spi_gpio_probe(struct platfor
  36         struct spi_gpio_platform_data   *pdata;
  37         u16 master_flags = 0;
  38         bool use_of = 0;
  39 +       int num_devices;
  40
  41         status = spi_gpio_probe_dt(pdev);
  42         if (status < 0)
  43 @@ -433,16 +434,21 @@ static int spi_gpio_probe(struct platfor
  44
  45         pdata = dev_get_platdata(&pdev->dev);
  46  #ifdef GENERIC_BITBANG
  47 -       if (!pdata || !pdata->num_chipselect)
  48 +       if (!pdata || (!use_of && !pdata->num_chipselect))
  49                 return -ENODEV;
  50  #endif
  51
  52 +       if (use_of && !SPI_N_CHIPSEL)
  53 +               num_devices = 1;
  54 +       else
  55 +               num_devices = SPI_N_CHIPSEL;
  56 +
  57         status = spi_gpio_request(pdata, dev_name(&pdev->dev), &master_flags);
  58         if (status < 0)
  59                 return status;
  60
  61         master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio) +
  62 -                                       (sizeof(int) * SPI_N_CHIPSEL));
  63 +                                       (sizeof(int) * num_devices));
  64         if (!master) {
  65                 status = -ENOMEM;
  66                 goto gpio_free;
  67 @@ -457,7 +463,7 @@ static int spi_gpio_probe(struct platfor
  68         master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
  69         master->flags = master_flags;
  70         master->bus_num = pdev->id;
  71 -       master->num_chipselect = SPI_N_CHIPSEL;
  72 +       master->num_chipselect = num_devices;
  73         master->setup = spi_gpio_setup;
  74         master->cleanup = spi_gpio_cleanup;
  75  #ifdef CONFIG_OF
  76 @@ -472,9 +478,12 @@ static int spi_gpio_probe(struct platfor
  77                  * property of the node.
  78                  */
  79
  80 -               for (i = 0; i < SPI_N_CHIPSEL; i++)
  81 -                       spi_gpio->cs_gpios[i] =
  82 -                               of_get_named_gpio(np, "cs-gpios", i);
  83 +               if (!SPI_N_CHIPSEL)
  84 +                       spi_gpio->cs_gpios[0] = SPI_GPIO_NO_CHIPSELECT;
  85 +               else
  86 +                       for (i = 0; i < SPI_N_CHIPSEL; i++)
  87 +                               spi_gpio->cs_gpios[i] =
  88 +                                       of_get_named_gpio(np, "cs-gpios", i);
  89         }
  90  #endif
  91