From 249e2632dcd0509b8f8f296f5aabf4d48dfd6da8 Mon Sep 17 00:00:00 2001 From: Andrey Smirnov Date: Tue, 2 Apr 2019 21:01:27 -0700 Subject: [PATCH] spi: gpio: Don't request CS GPIO in DT use-case DT use-case already relies on SPI core to control CS (requested by of_spi_register_master() and controlled spi_set_cs()), so there's no need to try to request those GPIO in spi-gpio code. Change the code such that spi-gpio's CS related code is only used if device is probed via pdata. Signed-off-by: Andrey Smirnov Cc: Mark Brown Cc: Chris Healy Cc: linux-spi@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Mark Brown --- drivers/spi/spi-gpio.c | 134 ++++++++++++++++++----------------------- 1 file changed, 59 insertions(+), 75 deletions(-) diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index c8fe87ebf8c8..3d05c6a71706 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -46,7 +46,6 @@ struct spi_gpio { struct gpio_desc *miso; struct gpio_desc *mosi; struct gpio_desc **cs_gpios; - bool has_cs; }; /*----------------------------------------------------------------------*/ @@ -216,7 +215,7 @@ static void spi_gpio_chipselect(struct spi_device *spi, int is_active) gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL); /* Drive chip select line, if we have one */ - if (spi_gpio->has_cs) { + if (spi_gpio->cs_gpios) { struct gpio_desc *cs = spi_gpio->cs_gpios[spi->chip_select]; /* SPI chip selects are normally active-low */ @@ -234,10 +233,12 @@ static int spi_gpio_setup(struct spi_device *spi) * The CS GPIOs have already been * initialized from the descriptor lookup. */ - cs = spi_gpio->cs_gpios[spi->chip_select]; - if (!spi->controller_state && cs) - status = gpiod_direction_output(cs, - !(spi->mode & SPI_CS_HIGH)); + if (spi_gpio->cs_gpios) { + cs = spi_gpio->cs_gpios[spi->chip_select]; + if (!spi->controller_state && cs) + status = gpiod_direction_output(cs, + !(spi->mode & SPI_CS_HIGH)); + } if (!status) status = spi_bitbang_setup(spi); @@ -290,11 +291,8 @@ static void spi_gpio_cleanup(struct spi_device *spi) */ static int spi_gpio_request(struct device *dev, struct spi_gpio *spi_gpio, - unsigned int num_chipselects, u16 *mflags) { - int i; - spi_gpio->mosi = devm_gpiod_get_optional(dev, "mosi", GPIOD_OUT_LOW); if (IS_ERR(spi_gpio->mosi)) return PTR_ERR(spi_gpio->mosi); @@ -315,13 +313,6 @@ static int spi_gpio_request(struct device *dev, if (IS_ERR(spi_gpio->sck)) return PTR_ERR(spi_gpio->sck); - for (i = 0; i < num_chipselects; i++) { - spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs", - i, GPIOD_OUT_HIGH); - if (IS_ERR(spi_gpio->cs_gpios[i])) - return PTR_ERR(spi_gpio->cs_gpios[i]); - } - return 0; } @@ -332,90 +323,87 @@ static const struct of_device_id spi_gpio_dt_ids[] = { }; MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids); -static int spi_gpio_probe_dt(struct platform_device *pdev) +static int spi_gpio_probe_dt(struct platform_device *pdev, + struct spi_master *master) { - int ret; - u32 tmp; - struct spi_gpio_platform_data *pdata; - struct device_node *np = pdev->dev.of_node; - const struct of_device_id *of_id = - of_match_device(spi_gpio_dt_ids, &pdev->dev); - - if (!of_id) - return 0; + master->dev.of_node = pdev->dev.of_node; + master->use_gpio_descriptors = true; - pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); - if (!pdata) - return -ENOMEM; + return 0; +} +#else +static inline int spi_gpio_probe_dt(struct platform_device *pdev, + struct spi_master *master) +{ + return 0; +} +#endif +static int spi_gpio_probe_pdata(struct platform_device *pdev, + struct spi_master *master) +{ + struct device *dev = &pdev->dev; + struct spi_gpio_platform_data *pdata = dev_get_platdata(dev); + struct spi_gpio *spi_gpio = spi_master_get_devdata(master); + int i; - ret = of_property_read_u32(np, "num-chipselects", &tmp); - if (ret < 0) { - dev_err(&pdev->dev, "num-chipselects property not found\n"); - goto error_free; - } +#ifdef GENERIC_BITBANG + if (!pdata || !pdata->num_chipselect) + return -ENODEV; +#endif + /* + * The master needs to think there is a chipselect even if not + * connected + */ + master->num_chipselect = pdata->num_chipselect ?: 1; - pdata->num_chipselect = tmp; - pdev->dev.platform_data = pdata; + spi_gpio->cs_gpios = devm_kcalloc(dev, master->num_chipselect, + sizeof(*spi_gpio->cs_gpios), + GFP_KERNEL); + if (!spi_gpio->cs_gpios) + return -ENOMEM; - return 1; + for (i = 0; i < master->num_chipselect; i++) { + spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs", i, + GPIOD_OUT_HIGH); + if (IS_ERR(spi_gpio->cs_gpios[i])) + return PTR_ERR(spi_gpio->cs_gpios[i]); + } -error_free: - devm_kfree(&pdev->dev, pdata); - return ret; -} -#else -static inline int spi_gpio_probe_dt(struct platform_device *pdev) -{ return 0; } -#endif static int spi_gpio_probe(struct platform_device *pdev) { int status; struct spi_master *master; struct spi_gpio *spi_gpio; - struct spi_gpio_platform_data *pdata; struct device *dev = &pdev->dev; struct spi_bitbang *bb; + const struct of_device_id *of_id; u16 master_flags = 0; - bool use_of = 0; - - status = spi_gpio_probe_dt(pdev); - if (status < 0) - return status; - if (status > 0) - use_of = 1; - pdata = dev_get_platdata(dev); -#ifdef GENERIC_BITBANG - if (!pdata || (!use_of && !pdata->num_chipselect)) - return -ENODEV; -#endif + of_id = of_match_device(spi_gpio_dt_ids, &pdev->dev); master = spi_alloc_master(dev, sizeof(*spi_gpio)); if (!master) return -ENOMEM; - spi_gpio = spi_master_get_devdata(master); + if (of_id) + status = spi_gpio_probe_dt(pdev, master); + else + status = spi_gpio_probe_pdata(pdev, master); - spi_gpio->cs_gpios = devm_kcalloc(dev, - pdata->num_chipselect, - sizeof(*spi_gpio->cs_gpios), - GFP_KERNEL); - if (!spi_gpio->cs_gpios) - return -ENOMEM; + if (status) + return status; - platform_set_drvdata(pdev, spi_gpio); + spi_gpio = spi_master_get_devdata(master); - /* Determine if we have chip selects connected */ - spi_gpio->has_cs = !!pdata->num_chipselect; + platform_set_drvdata(pdev, spi_gpio); spi_gpio->pdev = pdev; - status = spi_gpio_request(dev, spi_gpio, - pdata->num_chipselect, &master_flags); + status = spi_gpio_request(dev, spi_gpio, &master_flags); if (status) return status; @@ -424,13 +412,9 @@ static int spi_gpio_probe(struct platform_device *pdev) SPI_CS_HIGH; master->flags = master_flags; master->bus_num = pdev->id; - /* The master needs to think there is a chipselect even if not connected */ - master->num_chipselect = spi_gpio->has_cs ? pdata->num_chipselect : 1; master->setup = spi_gpio_setup; master->cleanup = spi_gpio_cleanup; -#ifdef CONFIG_OF - master->dev.of_node = dev->of_node; -#endif + bb = &spi_gpio->bitbang; bb->master = master; bb->chipselect = spi_gpio_chipselect; -- GitLab