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