From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Packham Subject: [RFC PATCH 1/5] spi: use gpio_desc instead of numeric gpio Date: Thu, 25 May 2017 16:30:39 +1200 Message-ID: <20170525043043.1930-2-chris.packham@alliedtelesis.co.nz> References: <20170525043043.1930-1-chris.packham@alliedtelesis.co.nz> Cc: linux@armlinux.org.uk, Chris Packham To: broonie@kernel.org, andy.shevchenko@gmail.com, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, rmallon@gmail.com, shawnguo@kernel.org Return-path: In-Reply-To: <20170525043043.1930-1-chris.packham@alliedtelesis.co.nz> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org By using a gpio_desc and gpiod_set_value() instead of a numeric gpio and gpio_set_value() the gpio flags are taken into account. This is useful when using a gpio chip-select to supplement a controllers native chip-select. Signed-off-by: Chris Packham --- (I've included this in this series for context, ultimately it should not be needed once everything is using gpio_desc) My specific use-case is I have a board that uses the spi-orion driver but only has one CS pin available. In order to access two spi slave devices the board has a 1-of-2 decoder/demultiplexer which is driven via a gpio. The problem is that for one of the 2 slave devices the gpio level required is opposite to the chip-select so I can't simply specify "spi-cs-high". With this change I can flag the gpio as active low and the gpio subsystem takes care of the additional inversion required. drivers/spi/spi.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 6f87fec409b5..b39c0f9956dd 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -725,7 +725,10 @@ static void spi_set_cs(struct spi_device *spi, bool enable) enable = !enable; if (gpio_is_valid(spi->cs_gpio)) { - gpio_set_value(spi->cs_gpio, !enable); + struct gpio_desc *gpio = gpio_to_desc(spi->cs_gpio); + + if (gpio) + gpiod_set_value(gpio, !enable); /* Some SPI masters need both GPIO CS & slave_select */ if ((spi->master->flags & SPI_MASTER_GPIO_SS) && spi->master->set_cs) -- 2.13.0