gpio: Handle counting of Freescale chipselects
[ Upstream commit5.4-rM2-2.2.x-imx-squashed71b8f600b0
] We have a special quirk to handle the Freescale nonstandard SPI chipselect GPIOs in the gpiolib-of.c file, but it currently only handles the case where the GPIOs are actually requested (gpiod_*get()). We also need to handle that the SPI core attempts to count the GPIOs before use, and that needs a similar quirk in the OF part of the library. Cc: Christophe Leroy <christophe.leroy@c-s.fr> Reported-by: Christophe Leroy <christophe.leroy@c-s.fr> Fixes:0f0581b24b
("spi: fsl: Convert to use CS GPIO descriptors") Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> Link: https://lore.kernel.org/r/20191128083718.39177-2-linus.walleij@linaro.org Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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9d646e70f6
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b8ec95e4b9
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@ -23,6 +23,29 @@
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#include "gpiolib.h"
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#include "gpiolib-of.h"
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/**
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* of_gpio_spi_cs_get_count() - special GPIO counting for SPI
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* Some elder GPIO controllers need special quirks. Currently we handle
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* the Freescale GPIO controller with bindings that doesn't use the
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* established "cs-gpios" for chip selects but instead rely on
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* "gpios" for the chip select lines. If we detect this, we redirect
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* the counting of "cs-gpios" to count "gpios" transparent to the
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* driver.
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*/
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int of_gpio_spi_cs_get_count(struct device *dev, const char *con_id)
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{
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struct device_node *np = dev->of_node;
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if (!IS_ENABLED(CONFIG_SPI_MASTER))
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return 0;
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if (!con_id || strcmp(con_id, "cs"))
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return 0;
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if (!of_device_is_compatible(np, "fsl,spi") &&
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!of_device_is_compatible(np, "aeroflexgaisler,spictrl"))
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return 0;
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return of_gpio_named_count(np, "gpios");
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}
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/*
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* This is used by external users of of_gpio_count() from <linux/of_gpio.h>
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*
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@ -35,6 +58,10 @@ int of_gpio_get_count(struct device *dev, const char *con_id)
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char propname[32];
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unsigned int i;
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ret = of_gpio_spi_cs_get_count(dev, con_id);
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if (ret > 0)
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return ret;
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for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
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if (con_id)
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snprintf(propname, sizeof(propname), "%s-%s",
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