tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 <mach/regs-gpio.h>
25#include <mach/spi-gpio.h>
26#include <mach/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 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.chipselect = s3c2410_spigpio_chipselect;
122
123 sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0;
124 sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1;
125 sp->bitbang.txrx_word[SPI_MODE_2] = s3c2410_spigpio_txrx_mode2;
126 sp->bitbang.txrx_word[SPI_MODE_3] = s3c2410_spigpio_txrx_mode3;
127
128 /* set state of spi pins, always assume that the clock is
129 * available, but do check the MOSI and MISO. */
130 s3c2410_gpio_setpin(info->pin_clk, 0);
131 s3c2410_gpio_cfgpin(info->pin_clk, S3C2410_GPIO_OUTPUT);
132
133 if (info->pin_mosi < S3C2410_GPH10) {
134 s3c2410_gpio_setpin(info->pin_mosi, 0);
135 s3c2410_gpio_cfgpin(info->pin_mosi, S3C2410_GPIO_OUTPUT);
136 }
137
138 if (info->pin_miso != S3C2410_GPA0 && info->pin_miso < S3C2410_GPH10)
139 s3c2410_gpio_cfgpin(info->pin_miso, S3C2410_GPIO_INPUT);
140
141 ret = spi_bitbang_start(&sp->bitbang);
142 if (ret)
143 goto err_no_bitbang;
144
145 return 0;
146
147 err_no_bitbang:
148 spi_master_put(sp->bitbang.master);
149 err:
150 return ret;
151
152}
153
154static int s3c2410_spigpio_remove(struct platform_device *dev)
155{
156 struct s3c2410_spigpio *sp = platform_get_drvdata(dev);
157
158 spi_bitbang_stop(&sp->bitbang);
159 spi_master_put(sp->bitbang.master);
160
161 return 0;
162}
163
164/* all gpio should be held over suspend/resume, so we should
165 * not need to deal with this
166*/
167
168#define s3c2410_spigpio_suspend NULL
169#define s3c2410_spigpio_resume NULL
170
171/* work with hotplug and coldplug */
172MODULE_ALIAS("platform:spi_s3c24xx_gpio");
173
174static struct platform_driver s3c2410_spigpio_drv = {
175 .probe = s3c2410_spigpio_probe,
176 .remove = s3c2410_spigpio_remove,
177 .suspend = s3c2410_spigpio_suspend,
178 .resume = s3c2410_spigpio_resume,
179 .driver = {
180 .name = "spi_s3c24xx_gpio",
181 .owner = THIS_MODULE,
182 },
183};
184
185static int __init s3c2410_spigpio_init(void)
186{
187 return platform_driver_register(&s3c2410_spigpio_drv);
188}
189
190static void __exit s3c2410_spigpio_exit(void)
191{
192 platform_driver_unregister(&s3c2410_spigpio_drv);
193}
194
195module_init(s3c2410_spigpio_init);
196module_exit(s3c2410_spigpio_exit);
197
198MODULE_DESCRIPTION("S3C24XX SPI Driver");
199MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
200MODULE_LICENSE("GPL");