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 <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 void s3c2410_spigpio_chipselect(struct spi_device *dev, int value)
77{
78 struct s3c2410_spigpio *sg = spidev_to_sg(dev);
79
80 if (sg->info && sg->info->chip_select)
81 (sg->info->chip_select)(sg->info, value);
82}
83
84static int s3c2410_spigpio_probe(struct platform_device *dev)
85{
86 struct spi_master *master;
87 struct s3c2410_spigpio *sp;
88 int ret;
89 int i;
90
91 master = spi_alloc_master(&dev->dev, sizeof(struct s3c2410_spigpio));
92 if (master == NULL) {
93 dev_err(&dev->dev, "failed to allocate spi master\n");
94 ret = -ENOMEM;
95 goto err;
96 }
97
98 sp = spi_master_get_devdata(master);
99
100 platform_set_drvdata(dev, sp);
101
102 /* copy in the plkatform data */
103 sp->info = dev->dev.platform_data;
104
105 /* setup spi bitbang adaptor */
106 sp->bitbang.master = spi_master_get(master);
107 sp->bitbang.chipselect = s3c2410_spigpio_chipselect;
108
109 sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0;
110 sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1;
111
112 /* set state of spi pins */
113 s3c2410_gpio_setpin(sp->info->pin_clk, 0);
114 s3c2410_gpio_setpin(sp->info->pin_mosi, 0);
115
116 s3c2410_gpio_cfgpin(sp->info->pin_clk, S3C2410_GPIO_OUTPUT);
117 s3c2410_gpio_cfgpin(sp->info->pin_mosi, S3C2410_GPIO_OUTPUT);
118 s3c2410_gpio_cfgpin(sp->info->pin_miso, S3C2410_GPIO_INPUT);
119
120 ret = spi_bitbang_start(&sp->bitbang);
121 if (ret)
122 goto err_no_bitbang;
123
124 /* register the chips to go with the board */
125
126 for (i = 0; i < sp->info->board_size; i++) {
127 dev_info(&dev->dev, "registering %p: %s\n",
128 &sp->info->board_info[i],
129 sp->info->board_info[i].modalias);
130
131 sp->info->board_info[i].controller_data = sp;
132 spi_new_device(master, sp->info->board_info + i);
133 }
134
135 return 0;
136
137 err_no_bitbang:
138 spi_master_put(sp->bitbang.master);
139 err:
140 return ret;
141
142}
143
144static int s3c2410_spigpio_remove(struct platform_device *dev)
145{
146 struct s3c2410_spigpio *sp = platform_get_drvdata(dev);
147
148 spi_bitbang_stop(&sp->bitbang);
149 spi_master_put(sp->bitbang.master);
150
151 return 0;
152}
153
154/* all gpio should be held over suspend/resume, so we should
155 * not need to deal with this
156*/
157
158#define s3c2410_spigpio_suspend NULL
159#define s3c2410_spigpio_resume NULL
160
161
162static struct platform_driver s3c2410_spigpio_drv = {
163 .probe = s3c2410_spigpio_probe,
164 .remove = s3c2410_spigpio_remove,
165 .suspend = s3c2410_spigpio_suspend,
166 .resume = s3c2410_spigpio_resume,
167 .driver = {
168 .name = "s3c24xx-spi-gpio",
169 .owner = THIS_MODULE,
170 },
171};
172
173static int __init s3c2410_spigpio_init(void)
174{
175 return platform_driver_register(&s3c2410_spigpio_drv);
176}
177
178static void __exit s3c2410_spigpio_exit(void)
179{
180 platform_driver_unregister(&s3c2410_spigpio_drv);
181}
182
183module_init(s3c2410_spigpio_init);
184module_exit(s3c2410_spigpio_exit);
185
186MODULE_DESCRIPTION("S3C24XX SPI Driver");
187MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
188MODULE_LICENSE("GPL");