diff options
Diffstat (limited to 'drivers/spi/spi-gpio.c')
| -rw-r--r-- | drivers/spi/spi-gpio.c | 194 |
1 files changed, 156 insertions, 38 deletions
diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index 0094c645ff0..9f595535cf2 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -19,9 +19,11 @@ */ #include <linux/kernel.h> #include <linux/module.h> -#include <linux/init.h> #include <linux/platform_device.h> #include <linux/gpio.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_gpio.h> #include <linux/spi/spi.h> #include <linux/spi/spi_bitbang.h> @@ -46,6 +48,7 @@ struct spi_gpio { struct spi_bitbang bitbang; struct spi_gpio_platform_data pdata; struct platform_device *pdev; + int cs_gpios[0]; }; /*----------------------------------------------------------------------*/ @@ -89,15 +92,21 @@ struct spi_gpio { /*----------------------------------------------------------------------*/ -static inline const struct spi_gpio_platform_data * __pure -spi_to_pdata(const struct spi_device *spi) +static inline struct spi_gpio * __pure +spi_to_spi_gpio(const struct spi_device *spi) { const struct spi_bitbang *bang; - const struct spi_gpio *spi_gpio; + struct spi_gpio *spi_gpio; bang = spi_master_get_devdata(spi->master); spi_gpio = container_of(bang, struct spi_gpio, bitbang); - return &spi_gpio->pdata; + return spi_gpio; +} + +static inline struct spi_gpio_platform_data * __pure +spi_to_pdata(const struct spi_device *spi) +{ + return &spi_to_spi_gpio(spi)->pdata; } /* this is #defined to avoid unused-variable warnings when inlining */ @@ -105,17 +114,17 @@ spi_to_pdata(const struct spi_device *spi) static inline void setsck(const struct spi_device *spi, int is_on) { - gpio_set_value(SPI_SCK_GPIO, is_on); + gpio_set_value_cansleep(SPI_SCK_GPIO, is_on); } static inline void setmosi(const struct spi_device *spi, int is_on) { - gpio_set_value(SPI_MOSI_GPIO, is_on); + gpio_set_value_cansleep(SPI_MOSI_GPIO, is_on); } static inline int getmiso(const struct spi_device *spi) { - return !!gpio_get_value(SPI_MISO_GPIO); + return !!gpio_get_value_cansleep(SPI_MISO_GPIO); } #undef pdata @@ -210,7 +219,8 @@ static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi, static void spi_gpio_chipselect(struct spi_device *spi, int is_active) { - unsigned long cs = (unsigned long) spi->controller_data; + struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); + unsigned int cs = spi_gpio->cs_gpios[spi->chip_select]; /* set initial clock polarity */ if (is_active) @@ -218,28 +228,45 @@ static void spi_gpio_chipselect(struct spi_device *spi, int is_active) if (cs != SPI_GPIO_NO_CHIPSELECT) { /* SPI is normally active-low */ - gpio_set_value(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active); + gpio_set_value_cansleep(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active); } } static int spi_gpio_setup(struct spi_device *spi) { - unsigned long cs = (unsigned long) spi->controller_data; - int status = 0; - - if (spi->bits_per_word > 32) - return -EINVAL; + unsigned int cs; + int status = 0; + struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); + struct device_node *np = spi->master->dev.of_node; + + if (np) { + /* + * In DT environments, the CS GPIOs have already been + * initialized from the "cs-gpios" property of the node. + */ + cs = spi_gpio->cs_gpios[spi->chip_select]; + } else { + /* + * ... otherwise, take it from spi->controller_data + */ + cs = (unsigned int)(uintptr_t) spi->controller_data; + } if (!spi->controller_state) { if (cs != SPI_GPIO_NO_CHIPSELECT) { status = gpio_request(cs, dev_name(&spi->dev)); if (status) return status; - status = gpio_direction_output(cs, spi->mode & SPI_CS_HIGH); + status = gpio_direction_output(cs, + !(spi->mode & SPI_CS_HIGH)); } } - if (!status) + if (!status) { + /* in case it was initialized from static board data */ + spi_gpio->cs_gpios[spi->chip_select] = cs; status = spi_bitbang_setup(spi); + } + if (status) { if (!spi->controller_state && cs != SPI_GPIO_NO_CHIPSELECT) gpio_free(cs); @@ -249,14 +276,15 @@ static int spi_gpio_setup(struct spi_device *spi) static void spi_gpio_cleanup(struct spi_device *spi) { - unsigned long cs = (unsigned long) spi->controller_data; + struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); + unsigned int cs = spi_gpio->cs_gpios[spi->chip_select]; if (cs != SPI_GPIO_NO_CHIPSELECT) gpio_free(cs); spi_bitbang_cleanup(spi); } -static int __devinit spi_gpio_alloc(unsigned pin, const char *label, bool is_in) +static int spi_gpio_alloc(unsigned pin, const char *label, bool is_in) { int value; @@ -270,9 +298,8 @@ static int __devinit spi_gpio_alloc(unsigned pin, const char *label, bool is_in) return value; } -static int __devinit -spi_gpio_request(struct spi_gpio_platform_data *pdata, const char *label, - u16 *res_flags) +static int spi_gpio_request(struct spi_gpio_platform_data *pdata, + const char *label, u16 *res_flags) { int value; @@ -312,15 +339,88 @@ done: return value; } -static int __devinit spi_gpio_probe(struct platform_device *pdev) +#ifdef CONFIG_OF +static const struct of_device_id spi_gpio_dt_ids[] = { + { .compatible = "spi-gpio" }, + {} +}; +MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids); + +static int spi_gpio_probe_dt(struct platform_device *pdev) +{ + 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; + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + ret = of_get_named_gpio(np, "gpio-sck", 0); + if (ret < 0) { + dev_err(&pdev->dev, "gpio-sck property not found\n"); + goto error_free; + } + pdata->sck = ret; + + ret = of_get_named_gpio(np, "gpio-miso", 0); + if (ret < 0) { + dev_info(&pdev->dev, "gpio-miso property not found, switching to no-rx mode\n"); + pdata->miso = SPI_GPIO_NO_MISO; + } else + pdata->miso = ret; + + ret = of_get_named_gpio(np, "gpio-mosi", 0); + if (ret < 0) { + dev_info(&pdev->dev, "gpio-mosi property not found, switching to no-tx mode\n"); + pdata->mosi = SPI_GPIO_NO_MOSI; + } else + pdata->mosi = ret; + + 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; + } + + pdata->num_chipselect = tmp; + pdev->dev.platform_data = pdata; + + return 1; + +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; 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 = pdev->dev.platform_data; + pdata = dev_get_platdata(&pdev->dev); #ifdef GENERIC_BITBANG if (!pdata || !pdata->num_chipselect) return -ENODEV; @@ -330,7 +430,8 @@ static int __devinit spi_gpio_probe(struct platform_device *pdev) if (status < 0) return status; - master = spi_alloc_master(&pdev->dev, sizeof *spi_gpio); + master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio) + + (sizeof(int) * SPI_N_CHIPSEL)); if (!master) { status = -ENOMEM; goto gpio_free; @@ -342,13 +443,31 @@ static int __devinit spi_gpio_probe(struct platform_device *pdev) if (pdata) spi_gpio->pdata = *pdata; + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); master->flags = master_flags; master->bus_num = pdev->id; master->num_chipselect = SPI_N_CHIPSEL; master->setup = spi_gpio_setup; master->cleanup = spi_gpio_cleanup; +#ifdef CONFIG_OF + master->dev.of_node = pdev->dev.of_node; - spi_gpio->bitbang.master = spi_master_get(master); + if (use_of) { + int i; + struct device_node *np = pdev->dev.of_node; + + /* + * In DT environments, take the CS GPIO from the "cs-gpios" + * property of the node. + */ + + for (i = 0; i < SPI_N_CHIPSEL; i++) + spi_gpio->cs_gpios[i] = + of_get_named_gpio(np, "cs-gpios", i); + } +#endif + + spi_gpio->bitbang.master = master; spi_gpio->bitbang.chipselect = spi_gpio_chipselect; if ((master_flags & (SPI_MASTER_NO_TX | SPI_MASTER_NO_RX)) == 0) { @@ -367,7 +486,6 @@ static int __devinit spi_gpio_probe(struct platform_device *pdev) status = spi_bitbang_start(&spi_gpio->bitbang); if (status < 0) { - spi_master_put(spi_gpio->bitbang.master); gpio_free: if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) gpio_free(SPI_MISO_GPIO); @@ -380,37 +498,37 @@ gpio_free: return status; } -static int __devexit spi_gpio_remove(struct platform_device *pdev) +static int spi_gpio_remove(struct platform_device *pdev) { struct spi_gpio *spi_gpio; struct spi_gpio_platform_data *pdata; - int status; spi_gpio = platform_get_drvdata(pdev); - pdata = pdev->dev.platform_data; + pdata = dev_get_platdata(&pdev->dev); /* stop() unregisters child devices too */ - status = spi_bitbang_stop(&spi_gpio->bitbang); - spi_master_put(spi_gpio->bitbang.master); - - platform_set_drvdata(pdev, NULL); + spi_bitbang_stop(&spi_gpio->bitbang); if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) gpio_free(SPI_MISO_GPIO); if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) gpio_free(SPI_MOSI_GPIO); gpio_free(SPI_SCK_GPIO); + spi_master_put(spi_gpio->bitbang.master); - return status; + return 0; } MODULE_ALIAS("platform:" DRIVER_NAME); static struct platform_driver spi_gpio_driver = { - .driver.name = DRIVER_NAME, - .driver.owner = THIS_MODULE, + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(spi_gpio_dt_ids), + }, .probe = spi_gpio_probe, - .remove = __devexit_p(spi_gpio_remove), + .remove = spi_gpio_remove, }; module_platform_driver(spi_gpio_driver); |