summaryrefslogtreecommitdiff
path: root/drivers/video/via/via-gpio.c
blob: 595516aea6917dc5f19d5e725e139b07c7f00512 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
/*
 * Support for viafb GPIO ports.
 *
 * Copyright 2009 Jonathan Corbet <corbet@lwn.net>
 * Distributable under version 2 of the GNU General Public License.
 */

#include <linux/spinlock.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <linux/via-core.h>
#include <linux/via-gpio.h>

/*
 * The ports we know about.  Note that the port-25 gpios are not
 * mentioned in the datasheet.
 */

struct viafb_gpio {
	char *vg_name;	/* Data sheet name */
	u16 vg_io_port;
	u8  vg_port_index;
	int  vg_mask_shift;
};

static struct viafb_gpio viafb_all_gpios[] = {
	{
		.vg_name = "VGPIO0",  /* Guess - not in datasheet */
		.vg_io_port = VIASR,
		.vg_port_index = 0x25,
		.vg_mask_shift = 1
	},
	{
		.vg_name = "VGPIO1",
		.vg_io_port = VIASR,
		.vg_port_index = 0x25,
		.vg_mask_shift = 0
	},
	{
		.vg_name = "VGPIO2",  /* aka DISPCLKI0 */
		.vg_io_port = VIASR,
		.vg_port_index = 0x2c,
		.vg_mask_shift = 1
	},
	{
		.vg_name = "VGPIO3",  /* aka DISPCLKO0 */
		.vg_io_port = VIASR,
		.vg_port_index = 0x2c,
		.vg_mask_shift = 0
	},
	{
		.vg_name = "VGPIO4",  /* DISPCLKI1 */
		.vg_io_port = VIASR,
		.vg_port_index = 0x3d,
		.vg_mask_shift = 1
	},
	{
		.vg_name = "VGPIO5",  /* DISPCLKO1 */
		.vg_io_port = VIASR,
		.vg_port_index = 0x3d,
		.vg_mask_shift = 0
	},
};

#define VIAFB_NUM_GPIOS ARRAY_SIZE(viafb_all_gpios)

/*
 * This structure controls the active GPIOs, which may be a subset
 * of those which are known.
 */

struct viafb_gpio_cfg {
	struct gpio_chip gpio_chip;
	struct viafb_dev *vdev;
	struct viafb_gpio *active_gpios[VIAFB_NUM_GPIOS];
	char *gpio_names[VIAFB_NUM_GPIOS];
};

/*
 * GPIO access functions
 */
static void via_gpio_set(struct gpio_chip *chip, unsigned int nr,
			 int value)
{
	struct viafb_gpio_cfg *cfg = container_of(chip,
						  struct viafb_gpio_cfg,
						  gpio_chip);
	u8 reg;
	struct viafb_gpio *gpio;
	unsigned long flags;

	spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
	gpio = cfg->active_gpios[nr];
	reg = via_read_reg(VIASR, gpio->vg_port_index);
	reg |= 0x40 << gpio->vg_mask_shift;  /* output enable */
	if (value)
		reg |= 0x10 << gpio->vg_mask_shift;
	else
		reg &= ~(0x10 << gpio->vg_mask_shift);
	via_write_reg(VIASR, gpio->vg_port_index, reg);
	spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
}

static int via_gpio_dir_out(struct gpio_chip *chip, unsigned int nr,
			    int value)
{
	via_gpio_set(chip, nr, value);
	return 0;
}

/*
 * Set the input direction.  I'm not sure this is right; we should
 * be able to do input without disabling output.
 */
static int via_gpio_dir_input(struct gpio_chip *chip, unsigned int nr)
{
	struct viafb_gpio_cfg *cfg = container_of(chip,
						  struct viafb_gpio_cfg,
						  gpio_chip);
	struct viafb_gpio *gpio;
	unsigned long flags;

	spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
	gpio = cfg->active_gpios[nr];
	via_write_reg_mask(VIASR, gpio->vg_port_index, 0,
			0x40 << gpio->vg_mask_shift);
	spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
	return 0;
}

static int via_gpio_get(struct gpio_chip *chip, unsigned int nr)
{
	struct viafb_gpio_cfg *cfg = container_of(chip,
						  struct viafb_gpio_cfg,
						  gpio_chip);
	u8 reg;
	struct viafb_gpio *gpio;
	unsigned long flags;

	spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
	gpio = cfg->active_gpios[nr];
	reg = via_read_reg(VIASR, gpio->vg_port_index);
	spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
	return reg & (0x04 << gpio->vg_mask_shift);
}


static struct viafb_gpio_cfg gpio_config = {
	.gpio_chip = {
		.label = "VIAFB onboard GPIO",
		.owner = THIS_MODULE,
		.direction_output = via_gpio_dir_out,
		.set = via_gpio_set,
		.direction_input = via_gpio_dir_input,
		.get = via_gpio_get,
		.base = -1,
		.ngpio = 0,
		.can_sleep = 0
	}
};

/*
 * Manage the software enable bit.
 */
static void viafb_gpio_enable(struct viafb_gpio *gpio)
{
	via_write_reg_mask(VIASR, gpio->vg_port_index, 0x02, 0x02);
}

static void viafb_gpio_disable(struct viafb_gpio *gpio)
{
	via_write_reg_mask(VIASR, gpio->vg_port_index, 0, 0x02);
}

/*
 * Look up a specific gpio and return the number it was assigned.
 */
int viafb_gpio_lookup(const char *name)
{
	int i;

	for (i = 0; i < gpio_config.gpio_chip.ngpio; i++)
		if (!strcmp(name, gpio_config.active_gpios[i]->vg_name))
			return gpio_config.gpio_chip.base + i;
	return -1;
}
EXPORT_SYMBOL_GPL(viafb_gpio_lookup);

/*
 * Platform device stuff.
 */
static __devinit int viafb_gpio_probe(struct platform_device *platdev)
{
	struct viafb_dev *vdev = platdev->dev.platform_data;
	struct via_port_cfg *port_cfg = vdev->port_cfg;
	int i, ngpio = 0, ret;
	struct viafb_gpio *gpio;
	unsigned long flags;

	/*
	 * Set up entries for all GPIOs which have been configured to
	 * operate as such (as opposed to as i2c ports).
	 */
	for (i = 0; i < VIAFB_NUM_PORTS; i++) {
		if (port_cfg[i].mode != VIA_MODE_GPIO)
			continue;
		for (gpio = viafb_all_gpios;
		     gpio < viafb_all_gpios + VIAFB_NUM_GPIOS; gpio++)
			if (gpio->vg_port_index == port_cfg[i].ioport_index) {
				gpio_config.active_gpios[ngpio] = gpio;
				gpio_config.gpio_names[ngpio] = gpio->vg_name;
				ngpio++;
			}
	}
	gpio_config.gpio_chip.ngpio = ngpio;
	gpio_config.gpio_chip.names = gpio_config.gpio_names;
	gpio_config.vdev = vdev;
	if (ngpio == 0) {
		printk(KERN_INFO "viafb: no GPIOs configured\n");
		return 0;
	}
	/*
	 * Enable the ports.  They come in pairs, with a single
	 * enable bit for both.
	 */
	spin_lock_irqsave(&gpio_config.vdev->reg_lock, flags);
	for (i = 0; i < ngpio; i += 2)
		viafb_gpio_enable(gpio_config.active_gpios[i]);
	spin_unlock_irqrestore(&gpio_config.vdev->reg_lock, flags);
	/*
	 * Get registered.
	 */
	gpio_config.gpio_chip.base = -1;  /* Dynamic */
	ret = gpiochip_add(&gpio_config.gpio_chip);
	if (ret) {
		printk(KERN_ERR "viafb: failed to add gpios (%d)\n", ret);
		gpio_config.gpio_chip.ngpio = 0;
	}
	return ret;
}


static int viafb_gpio_remove(struct platform_device *platdev)
{
	unsigned long flags;
	int ret = 0, i;

	/*
	 * Get unregistered.
	 */
	if (gpio_config.gpio_chip.ngpio > 0) {
		ret = gpiochip_remove(&gpio_config.gpio_chip);
		if (ret) { /* Somebody still using it? */
			printk(KERN_ERR "Viafb: GPIO remove failed\n");
			return ret;
		}
	}
	/*
	 * Disable the ports.
	 */
	spin_lock_irqsave(&gpio_config.vdev->reg_lock, flags);
	for (i = 0; i < gpio_config.gpio_chip.ngpio; i += 2)
		viafb_gpio_disable(gpio_config.active_gpios[i]);
	gpio_config.gpio_chip.ngpio = 0;
	spin_unlock_irqrestore(&gpio_config.vdev->reg_lock, flags);
	return ret;
}

static struct platform_driver via_gpio_driver = {
	.driver = {
		.name = "viafb-gpio",
	},
	.probe = viafb_gpio_probe,
	.remove = viafb_gpio_remove,
};

int viafb_gpio_init(void)
{
	return platform_driver_register(&via_gpio_driver);
}

void viafb_gpio_exit(void)
{
	platform_driver_unregister(&via_gpio_driver);
}