diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 4b89e0a04ffd..fd2bfb4aa8c3 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -25,7 +25,9 @@ #include #include #include -#include +#include +#include /* FIXME: using chip internals */ +#include /* FIXME: using chip internals */ #include #include @@ -931,14 +933,19 @@ static int chip_match_name(struct gpio_chip *chip, void *data) static int bcm2835_spi_setup(struct spi_device *spi) { - int err; struct gpio_chip *chip; + enum gpio_lookup_flags lflags; + /* * sanity checking the native-chipselects */ if (spi->mode & SPI_NO_CS) return 0; - if (gpio_is_valid(spi->cs_gpio)) + /* + * The SPI core has successfully requested the CS GPIO line from the + * device tree, so we are done. + */ + if (spi->cs_gpiod) return 0; if (spi->chip_select > 1) { /* error in the case of native CS requested with CS > 1 @@ -949,29 +956,43 @@ static int bcm2835_spi_setup(struct spi_device *spi) "setup: only two native chip-selects are supported\n"); return -EINVAL; } - /* now translate native cs to GPIO */ + + /* + * 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; - /* and calculate the real CS */ - spi->cs_gpio = chip->base + 8 - spi->chip_select; + /* + * 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 as GPIO %i\n", - spi->chip_select, spi->cs_gpio); - - /* set up GPIO as output and pull to the correct level */ - err = gpio_direction_output(spi->cs_gpio, - (spi->mode & SPI_CS_HIGH) ? 0 : 1); - if (err) { - dev_err(&spi->dev, - "could not set CS%i gpio %i as output: %i", - spi->chip_select, spi->cs_gpio, err); - return err; - } + dev_info(&spi->dev, "setting up native-CS%i to use GPIO\n", + spi->chip_select); return 0; } @@ -989,6 +1010,7 @@ static int bcm2835_spi_probe(struct platform_device *pdev) platform_set_drvdata(pdev, ctlr); + ctlr->use_gpio_descriptors = true; ctlr->mode_bits = BCM2835_SPI_MODE_BITS; ctlr->bits_per_word_mask = SPI_BPW_MASK(8); ctlr->num_chipselect = 3;