target/linux/bcm27xx/patches-5.4/950-0135-spi-spi-bcm2835-Disable-forced-software-CS.patch

   1 From dc1e3fefce7abd7532fbc74e26df61a8ced1dcd6 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Tue, 15 Jan 2019 12:41:15 +0000
   4 Subject: [PATCH] spi: spi-bcm2835: Disable forced software CS
   5
   6 With GPIO CS used by the DTBs, allow hardware CS to be selected by an
   7 overlay.
   8
   9 Signed-off-by: Phil Elwell <phil@raspberrypi.org>
  10 ---
  11  drivers/spi/spi-bcm2835.c | 37 -------------------------------------
  12  1 file changed, 37 deletions(-)
  13
  14 --- a/drivers/spi/spi-bcm2835.c
  15 +++ b/drivers/spi/spi-bcm2835.c
  16 @@ -1279,43 +1279,6 @@ static int bcm2835_spi_setup(struct spi_
  17                 return -EINVAL;
  18         }
  19
  20 -       /*
  21 -        * Translate native CS to GPIO
  22 -        *
  23 -        * FIXME: poking around in the gpiolib internals like this is
  24 -        * not very good practice. Find a way to locate the real problem
  25 -        * and fix it. Why is the GPIO descriptor in spi->cs_gpiod
  26 -        * sometimes not assigned correctly? Erroneous device trees?
  27 -        */
  28 -
  29 -       /* get the gpio chip for the base */
  30 -       chip = gpiochip_find("pinctrl-bcm2835", chip_match_name);
  31 -       if (!chip)
  32 -               return 0;
  33 -
  34 -       /*
  35 -        * Retrieve the corresponding GPIO line used for CS.
  36 -        * The inversion semantics will be handled by the GPIO core
  37 -        * code, so we pass GPIOS_OUT_LOW for "unasserted" and
  38 -        * the correct flag for inversion semantics. The SPI_CS_HIGH
  39 -        * on spi->mode cannot be checked for polarity in this case
  40 -        * as the flag use_gpio_descriptors enforces SPI_CS_HIGH.
  41 -        */
  42 -       if (of_property_read_bool(spi->dev.of_node, "spi-cs-high"))
  43 -               lflags = GPIO_ACTIVE_HIGH;
  44 -       else
  45 -               lflags = GPIO_ACTIVE_LOW;
  46 -       spi->cs_gpiod = gpiochip_request_own_desc(chip, 8 - spi->chip_select,
  47 -                                                 DRV_NAME,
  48 -                                                 lflags,
  49 -                                                 GPIOD_OUT_LOW);
  50 -       if (IS_ERR(spi->cs_gpiod))
  51 -               return PTR_ERR(spi->cs_gpiod);
  52 -
  53 -       /* and set up the "mode" and level */
  54 -       dev_info(&spi->dev, "setting up native-CS%i to use GPIO\n",
  55 -                spi->chip_select);
  56 -
  57         return 0;
  58  }
  59