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#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#define EXPAND_BITBANG_TXRX
62#include <linux/spi/spi_bitbang.h>
63
64
65static u32 s3c2410_spigpio_txrx_mode0(struct spi_device *spi,
66 unsigned nsecs, u32 word, u8 bits)
67{
68 return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
69}
70
71static u32 s3c2410_spigpio_txrx_mode1(struct spi_device *spi,
72 unsigned nsecs, u32 word, u8 bits)
73{
74 return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
75}
76
77static u32 s3c2410_spigpio_txrx_mode2(struct spi_device *spi,
78 unsigned nsecs, u32 word, u8 bits)
79{
80 return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
81}
82
83static u32 s3c2410_spigpio_txrx_mode3(struct spi_device *spi,
84 unsigned nsecs, u32 word, u8 bits)
85{
86 return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
87}
88
89
90static void s3c2410_spigpio_chipselect(struct spi_device *dev, int value)
91{
92 struct s3c2410_spigpio *sg = spidev_to_sg(dev);
93
94 if (sg->info && sg->info->chip_select)
95 (sg->info->chip_select)(sg->info, value);
96}
97
98static int s3c2410_spigpio_probe(struct platform_device *dev)
99{
100 struct s3c2410_spigpio_info *info;
101 struct spi_master *master;
102 struct s3c2410_spigpio *sp;
103 int ret;
104
105 master = spi_alloc_master(&dev->dev, sizeof(struct s3c2410_spigpio));
106 if (master == NULL) {
107 dev_err(&dev->dev, "failed to allocate spi master\n");
108 ret = -ENOMEM;
109 goto err;
110 }
111
112 sp = spi_master_get_devdata(master);
113
114 platform_set_drvdata(dev, sp);
115
116 /* copy in the plkatform data */
117 info = sp->info = dev->dev.platform_data;
118
119 /* setup spi bitbang adaptor */
120 sp->bitbang.master = spi_master_get(master);
121 sp->bitbang.master->bus_num = info->bus_num;
122 sp->bitbang.master->num_chipselect = info->num_chipselect;
123 sp->bitbang.chipselect = s3c2410_spigpio_chipselect;
124
125 sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0;
126 sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1;
127 sp->bitbang.txrx_word[SPI_MODE_2] = s3c2410_spigpio_txrx_mode2;
128 sp->bitbang.txrx_word[SPI_MODE_3] = s3c2410_spigpio_txrx_mode3;
129
130 /* set state of spi pins, always assume that the clock is
131 * available, but do check the MOSI and MISO. */
132 s3c2410_gpio_setpin(info->pin_clk, 0);
133 s3c2410_gpio_cfgpin(info->pin_clk, S3C2410_GPIO_OUTPUT);
134
135 if (info->pin_mosi < S3C2410_GPH10) {
136 s3c2410_gpio_setpin(info->pin_mosi, 0);
137 s3c2410_gpio_cfgpin(info->pin_mosi, S3C2410_GPIO_OUTPUT);
138 }
139
140 if (info->pin_miso != S3C2410_GPA0 && info->pin_miso < S3C2410_GPH10)
141 s3c2410_gpio_cfgpin(info->pin_miso, S3C2410_GPIO_INPUT);
142
143 ret = spi_bitbang_start(&sp->bitbang);
144 if (ret)
145 goto err_no_bitbang;
146
147 return 0;
148
149 err_no_bitbang:
150 spi_master_put(sp->bitbang.master);
151 err:
152 return ret;
153
154}
155
156static int s3c2410_spigpio_remove(struct platform_device *dev)
157{
158 struct s3c2410_spigpio *sp = platform_get_drvdata(dev);
159
160 spi_bitbang_stop(&sp->bitbang);
161 spi_master_put(sp->bitbang.master);
162
163 return 0;
164}
165
166/* all gpio should be held over suspend/resume, so we should
167 * not need to deal with this
168*/
169
170#define s3c2410_spigpio_suspend NULL
171#define s3c2410_spigpio_resume NULL
172
173/* work with hotplug and coldplug */
174MODULE_ALIAS("platform:spi_s3c24xx_gpio");
175
176static struct platform_driver s3c2410_spigpio_drv = {
177 .probe = s3c2410_spigpio_probe,
178 .remove = s3c2410_spigpio_remove,
179 .suspend = s3c2410_spigpio_suspend,
180 .resume = s3c2410_spigpio_resume,
181 .driver = {
182 .name = "spi_s3c24xx_gpio",
183 .owner = THIS_MODULE,
184 },
185};
186
187static int __init s3c2410_spigpio_init(void)
188{
189 return platform_driver_register(&s3c2410_spigpio_drv);
190}
191
192static void __exit s3c2410_spigpio_exit(void)
193{
194 platform_driver_unregister(&s3c2410_spigpio_drv);
195}
196
197module_init(s3c2410_spigpio_init);
198module_exit(s3c2410_spigpio_exit);
199
200MODULE_DESCRIPTION("S3C24XX SPI Driver");
201MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
202MODULE_LICENSE("GPL");