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 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 spi_master	*master;
100	struct s3c2410_spigpio  *sp;
101	int ret;
102	int i;
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	sp->info = dev->dev.platform_data;
117
118	/* setup spi bitbang adaptor */
119	sp->bitbang.master = spi_master_get(master);
120	sp->bitbang.chipselect = s3c2410_spigpio_chipselect;
121
122	sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0;
123	sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1;
124	sp->bitbang.txrx_word[SPI_MODE_2] = s3c2410_spigpio_txrx_mode2;
125	sp->bitbang.txrx_word[SPI_MODE_3] = s3c2410_spigpio_txrx_mode3;
126
127	/* set state of spi pins */
128	s3c2410_gpio_setpin(sp->info->pin_clk, 0);
129	s3c2410_gpio_setpin(sp->info->pin_mosi, 0);
130
131	s3c2410_gpio_cfgpin(sp->info->pin_clk, S3C2410_GPIO_OUTPUT);
132	s3c2410_gpio_cfgpin(sp->info->pin_mosi, S3C2410_GPIO_OUTPUT);
133	s3c2410_gpio_cfgpin(sp->info->pin_miso, S3C2410_GPIO_INPUT);
134
135	ret = spi_bitbang_start(&sp->bitbang);
136	if (ret)
137		goto err_no_bitbang;
138
139	/* register the chips to go with the board */
140
141	for (i = 0; i < sp->info->board_size; i++) {
142		dev_info(&dev->dev, "registering %p: %s\n",
143			 &sp->info->board_info[i],
144			 sp->info->board_info[i].modalias);
145
146		sp->info->board_info[i].controller_data = sp;
147		spi_new_device(master, sp->info->board_info + i);
148	}
149
150	return 0;
151
152 err_no_bitbang:
153	spi_master_put(sp->bitbang.master);
154 err:
155	return ret;
156
157}
158
159static int s3c2410_spigpio_remove(struct platform_device *dev)
160{
161	struct s3c2410_spigpio *sp = platform_get_drvdata(dev);
162
163	spi_bitbang_stop(&sp->bitbang);
164	spi_master_put(sp->bitbang.master);
165
166	return 0;
167}
168
169/* all gpio should be held over suspend/resume, so we should
170 * not need to deal with this
171*/
172
173#define s3c2410_spigpio_suspend NULL
174#define s3c2410_spigpio_resume NULL
175
176
177static struct platform_driver s3c2410_spigpio_drv = {
178	.probe		= s3c2410_spigpio_probe,
179        .remove		= s3c2410_spigpio_remove,
180        .suspend	= s3c2410_spigpio_suspend,
181        .resume		= s3c2410_spigpio_resume,
182        .driver		= {
183		.name	= "s3c24xx-spi-gpio",
184		.owner	= THIS_MODULE,
185        },
186};
187
188static int __init s3c2410_spigpio_init(void)
189{
190        return platform_driver_register(&s3c2410_spigpio_drv);
191}
192
193static void __exit s3c2410_spigpio_exit(void)
194{
195        platform_driver_unregister(&s3c2410_spigpio_drv);
196}
197
198module_init(s3c2410_spigpio_init);
199module_exit(s3c2410_spigpio_exit);
200
201MODULE_DESCRIPTION("S3C24XX SPI Driver");
202MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
203MODULE_LICENSE("GPL");
204