[PATCH] S3C24XX: GPIO based SPI driver
SPI driver for SPI by GPIO on the Samsung S3C24XX series of SoC processors. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Cc: Greg KH <greg@kroah.com> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ben Dooks
Linus Torvalds
parent
1b81d6637d
commit
1fc7547d4b
5 changed files with 229 additions and 0 deletions
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@ -95,6 +95,14 @@ config SPI_PXA2XX
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The driver can be configured to use any SSP port and additional
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documentation can be found a Documentation/spi/pxa2xx.
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config SPI_S3C24XX_GPIO
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tristate "Samsung S3C24XX series SPI by GPIO"
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depends on SPI_MASTER && ARCH_S3C2410 && SPI_BITBANG && EXPERIMENTAL
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help
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SPI driver for Samsung S3C24XX series ARM SoCs using
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GPIO lines to provide the SPI bus. This can be used where
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the inbuilt hardware cannot provide the transfer mode, or
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where the board is using non hardware connected pins.
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#
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# Add new SPI master controllers in alphabetical order above this line
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#
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@ -15,6 +15,7 @@ obj-$(CONFIG_SPI_BITBANG) += spi_bitbang.o
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obj-$(CONFIG_SPI_BUTTERFLY) += spi_butterfly.o
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obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o
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obj-$(CONFIG_SPI_MPC83xx) += spi_mpc83xx.o
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obj-$(CONFIG_SPI_S3C24XX_GPIO) += spi_s3c24xx_gpio.o
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# ... add above this line ...
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# SPI protocol drivers (device/link on bus)
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@ -321,6 +321,7 @@ static void butterfly_attach(struct parport *p)
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* (firmware resets at45, acts as spi slave) or neither (we ignore
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* both, AVR uses AT45). Here we expect firmware for the first option.
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*/
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pp->info[0].max_speed_hz = 15 * 1000 * 1000;
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strcpy(pp->info[0].modalias, "mtd_dataflash");
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pp->info[0].platform_data = &flash;
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188
drivers/spi/spi_s3c24xx_gpio.c
Normal file
188
drivers/spi/spi_s3c24xx_gpio.c
Normal file
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@ -0,0 +1,188 @@
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/* linux/drivers/spi/spi_s3c24xx_gpio.c
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*
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* Copyright (c) 2006 Ben Dooks
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* Copyright (c) 2006 Simtec Electronics
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*
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* S3C24XX GPIO based SPI driver
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/config.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/spinlock.h>
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#include <linux/platform_device.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/spi_bitbang.h>
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#include <asm/arch/regs-gpio.h>
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#include <asm/arch/spi-gpio.h>
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#include <asm/arch/hardware.h>
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struct s3c2410_spigpio {
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struct spi_bitbang bitbang;
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struct s3c2410_spigpio_info *info;
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struct platform_device *dev;
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};
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static inline struct s3c2410_spigpio *spidev_to_sg(struct spi_device *spi)
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{
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return spi->controller_data;
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}
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static inline void setsck(struct spi_device *dev, int on)
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{
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struct s3c2410_spigpio *sg = spidev_to_sg(dev);
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s3c2410_gpio_setpin(sg->info->pin_clk, on ? 1 : 0);
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}
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static inline void setmosi(struct spi_device *dev, int on)
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{
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struct s3c2410_spigpio *sg = spidev_to_sg(dev);
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s3c2410_gpio_setpin(sg->info->pin_mosi, on ? 1 : 0);
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}
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static inline u32 getmiso(struct spi_device *dev)
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{
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struct s3c2410_spigpio *sg = spidev_to_sg(dev);
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return s3c2410_gpio_getpin(sg->info->pin_miso) ? 1 : 0;
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}
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#define spidelay(x) ndelay(x)
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#define EXPAND_BITBANG_TXRX
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#include <linux/spi/spi_bitbang.h>
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static u32 s3c2410_spigpio_txrx_mode0(struct spi_device *spi,
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unsigned nsecs, u32 word, u8 bits)
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{
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return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
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}
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static u32 s3c2410_spigpio_txrx_mode1(struct spi_device *spi,
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unsigned nsecs, u32 word, u8 bits)
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{
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return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
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}
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static void s3c2410_spigpio_chipselect(struct spi_device *dev, int value)
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{
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struct s3c2410_spigpio *sg = spidev_to_sg(dev);
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if (sg->info && sg->info->chip_select)
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(sg->info->chip_select)(sg->info, value);
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}
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static int s3c2410_spigpio_probe(struct platform_device *dev)
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{
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struct spi_master *master;
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struct s3c2410_spigpio *sp;
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int ret;
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int i;
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master = spi_alloc_master(&dev->dev, sizeof(struct s3c2410_spigpio));
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if (master == NULL) {
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dev_err(&dev->dev, "failed to allocate spi master\n");
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ret = -ENOMEM;
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goto err;
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}
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sp = spi_master_get_devdata(master);
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platform_set_drvdata(dev, sp);
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/* copy in the plkatform data */
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sp->info = dev->dev.platform_data;
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/* setup spi bitbang adaptor */
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sp->bitbang.master = spi_master_get(master);
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sp->bitbang.chipselect = s3c2410_spigpio_chipselect;
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sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0;
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sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1;
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/* set state of spi pins */
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s3c2410_gpio_setpin(sp->info->pin_clk, 0);
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s3c2410_gpio_setpin(sp->info->pin_mosi, 0);
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s3c2410_gpio_cfgpin(sp->info->pin_clk, S3C2410_GPIO_OUTPUT);
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s3c2410_gpio_cfgpin(sp->info->pin_mosi, S3C2410_GPIO_OUTPUT);
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s3c2410_gpio_cfgpin(sp->info->pin_miso, S3C2410_GPIO_INPUT);
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ret = spi_bitbang_start(&sp->bitbang);
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if (ret)
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goto err_no_bitbang;
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/* register the chips to go with the board */
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for (i = 0; i < sp->info->board_size; i++) {
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dev_info(&dev->dev, "registering %p: %s\n",
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&sp->info->board_info[i],
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sp->info->board_info[i].modalias);
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sp->info->board_info[i].controller_data = sp;
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spi_new_device(master, sp->info->board_info + i);
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}
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return 0;
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err_no_bitbang:
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spi_master_put(sp->bitbang.master);
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err:
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return ret;
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}
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static int s3c2410_spigpio_remove(struct platform_device *dev)
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{
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struct s3c2410_spigpio *sp = platform_get_drvdata(dev);
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spi_bitbang_stop(&sp->bitbang);
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spi_master_put(sp->bitbang.master);
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return 0;
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}
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/* all gpio should be held over suspend/resume, so we should
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* not need to deal with this
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*/
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#define s3c2410_spigpio_suspend NULL
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#define s3c2410_spigpio_resume NULL
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static struct platform_driver s3c2410_spigpio_drv = {
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.probe = s3c2410_spigpio_probe,
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.remove = s3c2410_spigpio_remove,
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.suspend = s3c2410_spigpio_suspend,
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.resume = s3c2410_spigpio_resume,
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.driver = {
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.name = "s3c24xx-spi-gpio",
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.owner = THIS_MODULE,
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},
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};
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static int __init s3c2410_spigpio_init(void)
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{
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return platform_driver_register(&s3c2410_spigpio_drv);
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}
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static void __exit s3c2410_spigpio_exit(void)
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{
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platform_driver_unregister(&s3c2410_spigpio_drv);
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}
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module_init(s3c2410_spigpio_init);
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module_exit(s3c2410_spigpio_exit);
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MODULE_DESCRIPTION("S3C24XX SPI Driver");
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MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
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MODULE_LICENSE("GPL");
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31
include/asm-arm/arch-s3c2410/spi-gpio.h
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31
include/asm-arm/arch-s3c2410/spi-gpio.h
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@ -0,0 +1,31 @@
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/* linux/include/asm-arm/arch-s3c2410/spi.h
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*
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* Copyright (c) 2006 Simtec Electronics
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* Ben Dooks <ben@simtec.co.uk>
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*
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* S3C2410 - SPI Controller platfrom_device info
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef __ASM_ARCH_SPIGPIO_H
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#define __ASM_ARCH_SPIGPIO_H __FILE__
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struct s3c2410_spigpio_info;
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struct spi_board_info;
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struct s3c2410_spigpio_info {
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unsigned long pin_clk;
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unsigned long pin_mosi;
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unsigned long pin_miso;
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unsigned long board_size;
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struct spi_board_info *board_info;
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void (*chip_select)(struct s3c2410_spigpio_info *spi, int cs);
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};
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#endif /* __ASM_ARCH_SPIGPIO_H */
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