1/* linux/drivers/spi/spi_s3c24xx_gpio.c 2 * 3 * Copyright (c) 2006 Ben Dooks 4 * Copyright (c) 2006 Simtec Electronics 5 * 6 * S3C24XX GPIO based SPI driver 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12*/ 13 14#include <linux/kernel.h> 15#include <linux/init.h> 16#include <linux/delay.h> 17#include <linux/spinlock.h> 18#include <linux/workqueue.h> 19#include <linux/platform_device.h> 20 21#include <linux/spi/spi.h> 22#include <linux/spi/spi_bitbang.h> 23 24#include <asm/arch/regs-gpio.h> 25#include <asm/arch/spi-gpio.h> 26#include <asm/hardware.h> 27 28struct s3c2410_spigpio { 29 struct spi_bitbang bitbang; 30 31 struct s3c2410_spigpio_info *info; 32 struct platform_device *dev; 33}; 34 35static inline struct s3c2410_spigpio *spidev_to_sg(struct spi_device *spi) 36{ 37 return spi->controller_data; 38} 39 40static inline void setsck(struct spi_device *dev, int on) 41{ 42 struct s3c2410_spigpio *sg = spidev_to_sg(dev); 43 s3c2410_gpio_setpin(sg->info->pin_clk, on ? 1 : 0); 44} 45 46static inline void setmosi(struct spi_device *dev, int on) 47{ 48 struct s3c2410_spigpio *sg = spidev_to_sg(dev); 49 s3c2410_gpio_setpin(sg->info->pin_mosi, on ? 1 : 0); 50} 51 52static inline u32 getmiso(struct spi_device *dev) 53{ 54 struct s3c2410_spigpio *sg = spidev_to_sg(dev); 55 return s3c2410_gpio_getpin(sg->info->pin_miso) ? 1 : 0; 56} 57 58#define spidelay(x) ndelay(x) 59 60#define EXPAND_BITBANG_TXRX 61#include <linux/spi/spi_bitbang.h> 62 63 64static u32 s3c2410_spigpio_txrx_mode0(struct spi_device *spi, 65 unsigned nsecs, u32 word, u8 bits) 66{ 67 return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits); 68} 69 70static u32 s3c2410_spigpio_txrx_mode1(struct spi_device *spi, 71 unsigned nsecs, u32 word, u8 bits) 72{ 73 return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits); 74} 75 76static u32 s3c2410_spigpio_txrx_mode2(struct spi_device *spi, 77 unsigned nsecs, u32 word, u8 bits) 78{ 79 return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits); 80} 81 82static u32 s3c2410_spigpio_txrx_mode3(struct spi_device *spi, 83 unsigned nsecs, u32 word, u8 bits) 84{ 85 return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits); 86} 87 88 89static void s3c2410_spigpio_chipselect(struct spi_device *dev, int value) 90{ 91 struct s3c2410_spigpio *sg = spidev_to_sg(dev); 92 93 if (sg->info && sg->info->chip_select) 94 (sg->info->chip_select)(sg->info, value); 95} 96 97static int s3c2410_spigpio_probe(struct platform_device *dev) 98{ 99 struct spi_master *master; 100 struct s3c2410_spigpio *sp; 101 int ret; 102 int i; 103 104 master = spi_alloc_master(&dev->dev, sizeof(struct s3c2410_spigpio)); 105 if (master == NULL) { 106 dev_err(&dev->dev, "failed to allocate spi master\n"); 107 ret = -ENOMEM; 108 goto err; 109 } 110 111 sp = spi_master_get_devdata(master); 112 113 platform_set_drvdata(dev, sp); 114 115 /* copy in the plkatform data */ 116 sp->info = dev->dev.platform_data; 117 118 /* setup spi bitbang adaptor */ 119 sp->bitbang.master = spi_master_get(master); 120 sp->bitbang.chipselect = s3c2410_spigpio_chipselect; 121 122 sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0; 123 sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1; 124 sp->bitbang.txrx_word[SPI_MODE_2] = s3c2410_spigpio_txrx_mode2; 125 sp->bitbang.txrx_word[SPI_MODE_3] = s3c2410_spigpio_txrx_mode3; 126 127 /* set state of spi pins */ 128 s3c2410_gpio_setpin(sp->info->pin_clk, 0); 129 s3c2410_gpio_setpin(sp->info->pin_mosi, 0); 130 131 s3c2410_gpio_cfgpin(sp->info->pin_clk, S3C2410_GPIO_OUTPUT); 132 s3c2410_gpio_cfgpin(sp->info->pin_mosi, S3C2410_GPIO_OUTPUT); 133 s3c2410_gpio_cfgpin(sp->info->pin_miso, S3C2410_GPIO_INPUT); 134 135 ret = spi_bitbang_start(&sp->bitbang); 136 if (ret) 137 goto err_no_bitbang; 138 139 /* register the chips to go with the board */ 140 141 for (i = 0; i < sp->info->board_size; i++) { 142 dev_info(&dev->dev, "registering %p: %s\n", 143 &sp->info->board_info[i], 144 sp->info->board_info[i].modalias); 145 146 sp->info->board_info[i].controller_data = sp; 147 spi_new_device(master, sp->info->board_info + i); 148 } 149 150 return 0; 151 152 err_no_bitbang: 153 spi_master_put(sp->bitbang.master); 154 err: 155 return ret; 156 157} 158 159static int s3c2410_spigpio_remove(struct platform_device *dev) 160{ 161 struct s3c2410_spigpio *sp = platform_get_drvdata(dev); 162 163 spi_bitbang_stop(&sp->bitbang); 164 spi_master_put(sp->bitbang.master); 165 166 return 0; 167} 168 169/* all gpio should be held over suspend/resume, so we should 170 * not need to deal with this 171*/ 172 173#define s3c2410_spigpio_suspend NULL 174#define s3c2410_spigpio_resume NULL 175 176 177static struct platform_driver s3c2410_spigpio_drv = { 178 .probe = s3c2410_spigpio_probe, 179 .remove = s3c2410_spigpio_remove, 180 .suspend = s3c2410_spigpio_suspend, 181 .resume = s3c2410_spigpio_resume, 182 .driver = { 183 .name = "s3c24xx-spi-gpio", 184 .owner = THIS_MODULE, 185 }, 186}; 187 188static int __init s3c2410_spigpio_init(void) 189{ 190 return platform_driver_register(&s3c2410_spigpio_drv); 191} 192 193static void __exit s3c2410_spigpio_exit(void) 194{ 195 platform_driver_unregister(&s3c2410_spigpio_drv); 196} 197 198module_init(s3c2410_spigpio_init); 199module_exit(s3c2410_spigpio_exit); 200 201MODULE_DESCRIPTION("S3C24XX SPI Driver"); 202MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>"); 203MODULE_LICENSE("GPL"); 204