diff options
Diffstat (limited to 'include/linux/spi')
| -rw-r--r-- | include/linux/spi/mmc_spi.h | 15 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 6 | ||||
| -rw-r--r-- | include/linux/spi/spi_gpio.h | 60 |
3 files changed, 78 insertions, 3 deletions
diff --git a/include/linux/spi/mmc_spi.h b/include/linux/spi/mmc_spi.h index a3626aedaec..0f4eb165f25 100644 --- a/include/linux/spi/mmc_spi.h +++ b/include/linux/spi/mmc_spi.h @@ -1,9 +1,10 @@ #ifndef __LINUX_SPI_MMC_SPI_H #define __LINUX_SPI_MMC_SPI_H +#include <linux/device.h> +#include <linux/spi/spi.h> #include <linux/interrupt.h> -struct device; struct mmc_host; /* Put this in platform_data of a device being used to manage an MMC/SD @@ -41,4 +42,16 @@ struct mmc_spi_platform_data { void (*setpower)(struct device *, unsigned int maskval); }; +#ifdef CONFIG_OF +extern struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi); +extern void mmc_spi_put_pdata(struct spi_device *spi); +#else +static inline struct mmc_spi_platform_data * +mmc_spi_get_pdata(struct spi_device *spi) +{ + return spi->dev.platform_data; +} +static inline void mmc_spi_put_pdata(struct spi_device *spi) {} +#endif /* CONFIG_OF */ + #endif /* __LINUX_SPI_MMC_SPI_H */ diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 4be01bb4437..68bb1c501d0 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -19,6 +19,8 @@ #ifndef __LINUX_SPI_H #define __LINUX_SPI_H +#include <linux/device.h> + /* * INTERFACES between SPI master-side drivers and SPI infrastructure. * (There's no SPI slave support for Linux yet...) @@ -325,9 +327,9 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum); * @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped * @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped * @len: size of rx and tx buffers (in bytes) - * @speed_hz: Select a speed other then the device default for this + * @speed_hz: Select a speed other than the device default for this * transfer. If 0 the default (from @spi_device) is used. - * @bits_per_word: select a bits_per_word other then the device default + * @bits_per_word: select a bits_per_word other than the device default * for this transfer. If 0 the default (from @spi_device) is used. * @cs_change: affects chipselect after this transfer completes * @delay_usecs: microseconds to delay after this transfer before diff --git a/include/linux/spi/spi_gpio.h b/include/linux/spi/spi_gpio.h new file mode 100644 index 00000000000..0f01a0f1f40 --- /dev/null +++ b/include/linux/spi/spi_gpio.h @@ -0,0 +1,60 @@ +#ifndef __LINUX_SPI_GPIO_H +#define __LINUX_SPI_GPIO_H + +/* + * For each bitbanged SPI bus, set up a platform_device node with: + * - name "spi_gpio" + * - id the same as the SPI bus number it implements + * - dev.platform data pointing to a struct spi_gpio_platform_data + * + * Or, see the driver code for information about speedups that are + * possible on platforms that support inlined access for GPIOs (no + * spi_gpio_platform_data is used). + * + * Use spi_board_info with these busses in the usual way, being sure + * that the controller_data being the GPIO used for each device's + * chipselect: + * + * static struct spi_board_info ... [] = { + * ... + * // this slave uses GPIO 42 for its chipselect + * .controller_data = (void *) 42, + * ... + * // this one uses GPIO 86 for its chipselect + * .controller_data = (void *) 86, + * ... + * }; + * + * If the bitbanged bus is later switched to a "native" controller, + * that platform_device and controller_data should be removed. + */ + +/** + * struct spi_gpio_platform_data - parameter for bitbanged SPI master + * @sck: number of the GPIO used for clock output + * @mosi: number of the GPIO used for Master Output, Slave In (MOSI) data + * @miso: number of the GPIO used for Master Input, Slave Output (MISO) data + * @num_chipselect: how many slaves to allow + * + * All GPIO signals used with the SPI bus managed through this driver + * (chipselects, MOSI, MISO, SCK) must be configured as GPIOs, instead + * of some alternate function. + * + * It can be convenient to use this driver with pins that have alternate + * functions associated with a "native" SPI controller if a driver for that + * controller is not available, or is missing important functionality. + * + * On platforms which can do so, configure MISO with a weak pullup unless + * there's an external pullup on that signal. That saves power by avoiding + * floating signals. (A weak pulldown would save power too, but many + * drivers expect to see all-ones data as the no slave "response".) + */ +struct spi_gpio_platform_data { + unsigned sck; + unsigned mosi; + unsigned miso; + + u16 num_chipselect; +}; + +#endif /* __LINUX_SPI_GPIO_H */ |