openwrt/target/linux/bcm27xx/patches-5.4/950-0135-spi-spi-bcm2835-Disable-forced-software-CS.patch
Álvaro Fernández Rojas a1383655cf bcm27xx: add linux 5.4 support
Tested on bcm2710 (Raspberry Pi 3B).

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2020-02-29 12:50:51 +01:00

60 lines
1.8 KiB
Diff

From dc1e3fefce7abd7532fbc74e26df61a8ced1dcd6 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Tue, 15 Jan 2019 12:41:15 +0000
Subject: [PATCH] spi: spi-bcm2835: Disable forced software CS
With GPIO CS used by the DTBs, allow hardware CS to be selected by an
overlay.
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
---
drivers/spi/spi-bcm2835.c | 37 -------------------------------------
1 file changed, 37 deletions(-)
--- a/drivers/spi/spi-bcm2835.c
+++ b/drivers/spi/spi-bcm2835.c
@@ -1279,43 +1279,6 @@ static int bcm2835_spi_setup(struct spi_
return -EINVAL;
}
- /*
- * Translate native CS to GPIO
- *
- * FIXME: poking around in the gpiolib internals like this is
- * not very good practice. Find a way to locate the real problem
- * and fix it. Why is the GPIO descriptor in spi->cs_gpiod
- * sometimes not assigned correctly? Erroneous device trees?
- */
-
- /* get the gpio chip for the base */
- chip = gpiochip_find("pinctrl-bcm2835", chip_match_name);
- if (!chip)
- return 0;
-
- /*
- * Retrieve the corresponding GPIO line used for CS.
- * The inversion semantics will be handled by the GPIO core
- * code, so we pass GPIOS_OUT_LOW for "unasserted" and
- * the correct flag for inversion semantics. The SPI_CS_HIGH
- * on spi->mode cannot be checked for polarity in this case
- * as the flag use_gpio_descriptors enforces SPI_CS_HIGH.
- */
- if (of_property_read_bool(spi->dev.of_node, "spi-cs-high"))
- lflags = GPIO_ACTIVE_HIGH;
- else
- lflags = GPIO_ACTIVE_LOW;
- spi->cs_gpiod = gpiochip_request_own_desc(chip, 8 - spi->chip_select,
- DRV_NAME,
- lflags,
- GPIOD_OUT_LOW);
- if (IS_ERR(spi->cs_gpiod))
- return PTR_ERR(spi->cs_gpiod);
-
- /* and set up the "mode" and level */
- dev_info(&spi->dev, "setting up native-CS%i to use GPIO\n",
- spi->chip_select);
-
return 0;
}