diff options
Diffstat (limited to 'drivers/spi/spi-s3c24xx-gpio.c')
| -rw-r--r-- | drivers/spi/spi-s3c24xx-gpio.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/spi/spi-s3c24xx-gpio.c b/drivers/spi/spi-s3c24xx-gpio.c new file mode 100644 index 0000000..2d3c085 --- /dev/null +++ b/drivers/spi/spi-s3c24xx-gpio.c @@ -0,0 +1,200 @@ +/* + * Copyright (c) 2006 Ben Dooks + * Copyright (c) 2006 Simtec Electronics + * + * S3C24XX GPIO based SPI driver + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * +*/ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> + +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> + +#include <mach/regs-gpio.h> +#include <mach/spi-gpio.h> +#include <mach/hardware.h> + +struct s3c2410_spigpio { + struct spi_bitbang bitbang; + + struct s3c2410_spigpio_info *info; + struct platform_device *dev; +}; + +static inline struct s3c2410_spigpio *spidev_to_sg(struct spi_device *spi) +{ + return spi_master_get_devdata(spi->master); +} + +static inline void setsck(struct spi_device *dev, int on) +{ + struct s3c2410_spigpio *sg = spidev_to_sg(dev); + s3c2410_gpio_setpin(sg->info->pin_clk, on ? 1 : 0); +} + +static inline void setmosi(struct spi_device *dev, int on) +{ + struct s3c2410_spigpio *sg = spidev_to_sg(dev); + s3c2410_gpio_setpin(sg->info->pin_mosi, on ? 1 : 0); +} + +static inline u32 getmiso(struct spi_device *dev) +{ + struct s3c2410_spigpio *sg = spidev_to_sg(dev); + return s3c2410_gpio_getpin(sg->info->pin_miso) ? 1 : 0; +} + +#define spidelay(x) ndelay(x) + +#include "spi-bitbang-txrx.h" + + +static u32 s3c2410_spigpio_txrx_mode0(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits); +} + +static u32 s3c2410_spigpio_txrx_mode1(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits); +} + +static u32 s3c2410_spigpio_txrx_mode2(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits); +} + +static u32 s3c2410_spigpio_txrx_mode3(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits); +} + + +static void s3c2410_spigpio_chipselect(struct spi_device *dev, int value) +{ + struct s3c2410_spigpio *sg = spidev_to_sg(dev); + + if (sg->info && sg->info->chip_select) + (sg->info->chip_select)(sg->info, value); +} + +static int s3c2410_spigpio_probe(struct platform_device *dev) +{ + struct s3c2410_spigpio_info *info; + struct spi_master *master; + struct s3c2410_spigpio *sp; + int ret; + + master = spi_alloc_master(&dev->dev, sizeof(struct s3c2410_spigpio)); + if (master == NULL) { + dev_err(&dev->dev, "failed to allocate spi master\n"); + ret = -ENOMEM; + goto err; + } + + sp = spi_master_get_devdata(master); + + platform_set_drvdata(dev, sp); + + /* copy in the plkatform data */ + info = sp->info = dev->dev.platform_data; + + /* setup spi bitbang adaptor */ + sp->bitbang.master = spi_master_get(master); + sp->bitbang.master->bus_num = info->bus_num; + sp->bitbang.master->num_chipselect = info->num_chipselect; + sp->bitbang.chipselect = s3c2410_spigpio_chipselect; + + sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0; + sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1; + sp->bitbang.txrx_word[SPI_MODE_2] = s3c2410_spigpio_txrx_mode2; + sp->bitbang.txrx_word[SPI_MODE_3] = s3c2410_spigpio_txrx_mode3; + + /* set state of spi pins, always assume that the clock is + * available, but do check the MOSI and MISO. */ + s3c2410_gpio_setpin(info->pin_clk, 0); + s3c2410_gpio_cfgpin(info->pin_clk, S3C2410_GPIO_OUTPUT); + + if (info->pin_mosi < S3C2410_GPH10) { + s3c2410_gpio_setpin(info->pin_mosi, 0); + s3c2410_gpio_cfgpin(info->pin_mosi, S3C2410_GPIO_OUTPUT); + } + + if (info->pin_miso != S3C2410_GPA0 && info->pin_miso < S3C2410_GPH10) + s3c2410_gpio_cfgpin(info->pin_miso, S3C2410_GPIO_INPUT); + + ret = spi_bitbang_start(&sp->bitbang); + if (ret) + goto err_no_bitbang; + + return 0; + + err_no_bitbang: + spi_master_put(sp->bitbang.master); + err: + return ret; + +} + +static int s3c2410_spigpio_remove(struct platform_device *dev) +{ + struct s3c2410_spigpio *sp = platform_get_drvdata(dev); + + spi_bitbang_stop(&sp->bitbang); + spi_master_put(sp->bitbang.master); + + return 0; +} + +/* all gpio should be held over suspend/resume, so we should + * not need to deal with this +*/ + +#define s3c2410_spigpio_suspend NULL +#define s3c2410_spigpio_resume NULL + +/* work with hotplug and coldplug */ +MODULE_ALIAS("platform:spi_s3c24xx_gpio"); + +static struct platform_driver s3c2410_spigpio_drv = { + .probe = s3c2410_spigpio_probe, + .remove = s3c2410_spigpio_remove, + .suspend = s3c2410_spigpio_suspend, + .resume = s3c2410_spigpio_resume, + .driver = { + .name = "spi_s3c24xx_gpio", + .owner = THIS_MODULE, + }, +}; + +static int __init s3c2410_spigpio_init(void) +{ + return platform_driver_register(&s3c2410_spigpio_drv); +} + +static void __exit s3c2410_spigpio_exit(void) +{ + platform_driver_unregister(&s3c2410_spigpio_drv); +} + +module_init(s3c2410_spigpio_init); +module_exit(s3c2410_spigpio_exit); + +MODULE_DESCRIPTION("S3C24XX SPI Driver"); +MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>"); +MODULE_LICENSE("GPL"); |
