target/linux/ar71xx/patches-4.4/104-spi-spi-ath79-support-multiple-internal-chip-select-.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Fri, 9 Dec 2016 20:09:16 +0100
   3 Subject: [PATCH] spi: spi-ath79: support multiple internal chip select
   4  lines
   5
   6 Several devices with multiple flash chips use the internal chip select
   7 lines. Don't assume that chip select 1 and above are GPIO lines.
   8
   9 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  10 ---
  11
  12 --- a/drivers/spi/spi-ath79.c
  13 +++ b/drivers/spi/spi-ath79.c
  14 @@ -78,14 +78,16 @@ static void ath79_spi_chipselect(struct
  15                 ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
  16         }
  17
  18 -       if (spi->chip_select) {
  19 +       if (gpio_is_valid(spi->cs_gpio)) {
  20                 /* SPI is normally active-low */
  21                 gpio_set_value(spi->cs_gpio, cs_high);
  22         } else {
  23 +               u32 cs_bit = AR71XX_SPI_IOC_CS(spi->chip_select);
  24 +
  25                 if (cs_high)
  26 -                       sp->ioc_base |= AR71XX_SPI_IOC_CS0;
  27 +                       sp->ioc_base |= cs_bit;
  28                 else
  29 -                       sp->ioc_base &= ~AR71XX_SPI_IOC_CS0;
  30 +                       sp->ioc_base &= ~cs_bit;
  31
  32                 ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
  33         }
  34 @@ -118,11 +120,8 @@ static int ath79_spi_setup_cs(struct spi
  35         struct ath79_spi *sp = ath79_spidev_to_sp(spi);
  36         int status;
  37
  38 -       if (spi->chip_select && !gpio_is_valid(spi->cs_gpio))
  39 -               return -EINVAL;
  40 -
  41         status = 0;
  42 -       if (spi->chip_select) {
  43 +       if (gpio_is_valid(spi->cs_gpio)) {
  44                 unsigned long flags;
  45
  46                 flags = GPIOF_DIR_OUT;
  47 @@ -134,10 +133,12 @@ static int ath79_spi_setup_cs(struct spi
  48                 status = gpio_request_one(spi->cs_gpio, flags,
  49                                           dev_name(&spi->dev));
  50         } else {
  51 +               u32 cs_bit = AR71XX_SPI_IOC_CS(spi->chip_select);
  52 +
  53                 if (spi->mode & SPI_CS_HIGH)
  54 -                       sp->ioc_base &= ~AR71XX_SPI_IOC_CS0;
  55 +                       sp->ioc_base &= ~cs_bit;
  56                 else
  57 -                       sp->ioc_base |= AR71XX_SPI_IOC_CS0;
  58 +                       sp->ioc_base |= cs_bit;
  59
  60                 ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
  61         }
  62 @@ -147,7 +148,7 @@ static int ath79_spi_setup_cs(struct spi
  63
  64  static void ath79_spi_cleanup_cs(struct spi_device *spi)
  65  {
  66 -       if (spi->chip_select) {
  67 +       if (gpio_is_valid(spi->cs_gpio)) {
  68                 gpio_free(spi->cs_gpio);
  69         }
  70  }