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#include <linux/gpio.h> 21 22#include <linux/spi/spi.h> 23#include <linux/spi/spi_bitbang.h> 24 25#include <mach/regs-gpio.h> 26#include <mach/spi-gpio.h> 27#include <mach/hardware.h> 28 29struct s3c2410_spigpio { 30 struct spi_bitbang bitbang; 31 32 struct s3c2410_spigpio_info *info; 33 struct platform_device *dev; 34}; 35 36static inline struct s3c2410_spigpio *spidev_to_sg(struct spi_device *spi) 37{ 38 return spi_master_get_devdata(spi->master); 39} 40 41static inline void setsck(struct spi_device *dev, int on) 42{ 43 struct s3c2410_spigpio *sg = spidev_to_sg(dev); 44 s3c2410_gpio_setpin(sg->info->pin_clk, on ? 1 : 0); 45} 46 47static inline void setmosi(struct spi_device *dev, int on) 48{ 49 struct s3c2410_spigpio *sg = spidev_to_sg(dev); 50 s3c2410_gpio_setpin(sg->info->pin_mosi, on ? 1 : 0); 51} 52 53static inline u32 getmiso(struct spi_device *dev) 54{ 55 struct s3c2410_spigpio *sg = spidev_to_sg(dev); 56 return s3c2410_gpio_getpin(sg->info->pin_miso) ? 1 : 0; 57} 58 59#define spidelay(x) ndelay(x) 60 61#include "spi_bitbang_txrx.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, 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, 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, 0, 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, 0, 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 s3c2410_spigpio_info *info; 100 struct spi_master *master; 101 struct s3c2410_spigpio *sp; 102 int ret; 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 info = sp->info = dev->dev.platform_data; 117 118 /* setup spi bitbang adaptor */ 119 sp->bitbang.master = spi_master_get(master); 120 sp->bitbang.master->bus_num = info->bus_num; 121 sp->bitbang.master->num_chipselect = info->num_chipselect; 122 sp->bitbang.chipselect = s3c2410_spigpio_chipselect; 123 124 sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0; 125 sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1; 126 sp->bitbang.txrx_word[SPI_MODE_2] = s3c2410_spigpio_txrx_mode2; 127 sp->bitbang.txrx_word[SPI_MODE_3] = s3c2410_spigpio_txrx_mode3; 128 129 /* set state of spi pins, always assume that the clock is 130 * available, but do check the MOSI and MISO. */ 131 s3c2410_gpio_setpin(info->pin_clk, 0); 132 s3c2410_gpio_cfgpin(info->pin_clk, S3C2410_GPIO_OUTPUT); 133 134 if (info->pin_mosi < S3C2410_GPH10) { 135 s3c2410_gpio_setpin(info->pin_mosi, 0); 136 s3c2410_gpio_cfgpin(info->pin_mosi, S3C2410_GPIO_OUTPUT); 137 } 138 139 if (info->pin_miso != S3C2410_GPA0 && info->pin_miso < S3C2410_GPH10) 140 s3c2410_gpio_cfgpin(info->pin_miso, S3C2410_GPIO_INPUT); 141 142 ret = spi_bitbang_start(&sp->bitbang); 143 if (ret) 144 goto err_no_bitbang; 145 146 return 0; 147 148 err_no_bitbang: 149 spi_master_put(sp->bitbang.master); 150 err: 151 return ret; 152 153} 154 155static int s3c2410_spigpio_remove(struct platform_device *dev) 156{ 157 struct s3c2410_spigpio *sp = platform_get_drvdata(dev); 158 159 spi_bitbang_stop(&sp->bitbang); 160 spi_master_put(sp->bitbang.master); 161 162 return 0; 163} 164 165/* all gpio should be held over suspend/resume, so we should 166 * not need to deal with this 167*/ 168 169#define s3c2410_spigpio_suspend NULL 170#define s3c2410_spigpio_resume NULL 171 172/* work with hotplug and coldplug */ 173MODULE_ALIAS("platform:spi_s3c24xx_gpio"); 174 175static struct platform_driver s3c2410_spigpio_drv = { 176 .probe = s3c2410_spigpio_probe, 177 .remove = s3c2410_spigpio_remove, 178 .suspend = s3c2410_spigpio_suspend, 179 .resume = s3c2410_spigpio_resume, 180 .driver = { 181 .name = "spi_s3c24xx_gpio", 182 .owner = THIS_MODULE, 183 }, 184}; 185 186static int __init s3c2410_spigpio_init(void) 187{ 188 return platform_driver_register(&s3c2410_spigpio_drv); 189} 190 191static void __exit s3c2410_spigpio_exit(void) 192{ 193 platform_driver_unregister(&s3c2410_spigpio_drv); 194} 195 196module_init(s3c2410_spigpio_init); 197module_exit(s3c2410_spigpio_exit); 198 199MODULE_DESCRIPTION("S3C24XX SPI Driver"); 200MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>"); 201MODULE_LICENSE("GPL"); 202