summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/panel/panel-olimex-lcd-olinuxino.c
blob: a1d8d92fac2b1f72db997110aadd3855c684bcab (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
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
// SPDX-License-Identifier: GPL-2.0+
/*
 * LCD-OLinuXino support for panel driver
 *
 * Copyright (C) 2018 Olimex Ltd.
 *   Author: Stefan Mavrodiev <stefan@olimex.com>
 */

#include <linux/backlight.h>
#include <linux/crc32.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>

#include <drm/drm_modes.h>
#include <drm/drm_panel.h>
#include <drm/drmP.h>

#include <video/videomode.h>
#include <video/display_timing.h>

#define LCD_OLINUXINO_HEADER_MAGIC	0x4F4CB727
#define LCD_OLINUXINO_DATA_LEN		256

struct lcd_olinuxino_mode {
	u32 pixelclock;
	u32 hactive;
	u32 hfp;
	u32 hbp;
	u32 hpw;
	u32 vactive;
	u32 vfp;
	u32 vbp;
	u32 vpw;
	u32 refresh;
	u32 flags;
};

struct lcd_olinuxino_info {
	char name[32];
	u32 width_mm;
	u32 height_mm;
	u32 bpc;
	u32 bus_format;
	u32 bus_flag;
} __attribute__((__packed__));

struct lcd_olinuxino_eeprom {
	u32 header;
	u32 id;
	char revision[4];
	u32 serial;
	struct lcd_olinuxino_info info;
	u32 num_modes;
	u8 reserved[180];
	u32 checksum;
} __attribute__((__packed__));

struct lcd_olinuxino {
	struct drm_panel panel;
	struct device *dev;
	struct i2c_client *client;
	struct mutex mutex;

	bool prepared;
	bool enabled;

	struct backlight_device *backlight;
	struct regulator *supply;
	struct gpio_desc *enable_gpio;

	struct lcd_olinuxino_eeprom eeprom;
};

static inline struct lcd_olinuxino *to_lcd_olinuxino(struct drm_panel *panel)
{
	return container_of(panel, struct lcd_olinuxino, panel);
}

static int lcd_olinuxino_disable(struct drm_panel *panel)
{
	struct lcd_olinuxino *lcd = to_lcd_olinuxino(panel);

	if (!lcd->enabled)
		return 0;

	backlight_disable(lcd->backlight);

	lcd->enabled = false;

	return 0;
}

static int lcd_olinuxino_unprepare(struct drm_panel *panel)
{
	struct lcd_olinuxino *lcd = to_lcd_olinuxino(panel);

	if (!lcd->prepared)
		return 0;

	gpiod_set_value_cansleep(lcd->enable_gpio, 0);
	regulator_disable(lcd->supply);

	lcd->prepared = false;

	return 0;
}

static int lcd_olinuxino_prepare(struct drm_panel *panel)
{
	struct lcd_olinuxino *lcd = to_lcd_olinuxino(panel);
	int ret;

	if (lcd->prepared)
		return 0;

	ret = regulator_enable(lcd->supply);
	if (ret < 0)
		return ret;

	gpiod_set_value_cansleep(lcd->enable_gpio, 1);
	lcd->prepared = true;

	return 0;
}

static int lcd_olinuxino_enable(struct drm_panel *panel)
{
	struct lcd_olinuxino *lcd = to_lcd_olinuxino(panel);

	if (lcd->enabled)
		return 0;

	backlight_enable(lcd->backlight);

	lcd->enabled = true;

	return 0;
}

static int lcd_olinuxino_get_modes(struct drm_panel *panel)
{
	struct lcd_olinuxino *lcd = to_lcd_olinuxino(panel);
	struct drm_connector *connector = lcd->panel.connector;
	struct lcd_olinuxino_info *lcd_info = &lcd->eeprom.info;
	struct drm_device *drm = lcd->panel.drm;
	struct lcd_olinuxino_mode *lcd_mode;
	struct drm_display_mode *mode;
	u32 i, num = 0;

	for (i = 0; i < lcd->eeprom.num_modes; i++) {
		lcd_mode = (struct lcd_olinuxino_mode *)
			   &lcd->eeprom.reserved[i * sizeof(*lcd_mode)];

		mode = drm_mode_create(drm);
		if (!mode) {
			dev_err(drm->dev, "failed to add mode %ux%u@%u\n",
				lcd_mode->hactive,
				lcd_mode->vactive,
				lcd_mode->refresh);
				continue;
		}

		mode->clock = lcd_mode->pixelclock;
		mode->hdisplay = lcd_mode->hactive;
		mode->hsync_start = lcd_mode->hactive + lcd_mode->hfp;
		mode->hsync_end = lcd_mode->hactive + lcd_mode->hfp +
				  lcd_mode->hpw;
		mode->htotal = lcd_mode->hactive + lcd_mode->hfp +
			       lcd_mode->hpw + lcd_mode->hbp;
		mode->vdisplay = lcd_mode->vactive;
		mode->vsync_start = lcd_mode->vactive + lcd_mode->vfp;
		mode->vsync_end = lcd_mode->vactive + lcd_mode->vfp +
				  lcd_mode->vpw;
		mode->vtotal = lcd_mode->vactive + lcd_mode->vfp +
			       lcd_mode->vpw + lcd_mode->vbp;
		mode->vrefresh = lcd_mode->refresh;

		/* Always make the first mode preferred */
		if (i == 0)
			mode->type |= DRM_MODE_TYPE_PREFERRED;
		mode->type |= DRM_MODE_TYPE_DRIVER;

		drm_mode_set_name(mode);
		drm_mode_probed_add(connector, mode);

		num++;
	}

	connector->display_info.width_mm = lcd_info->width_mm;
	connector->display_info.height_mm = lcd_info->height_mm;
	connector->display_info.bpc = lcd_info->bpc;

	if (lcd_info->bus_format)
		drm_display_info_set_bus_formats(&connector->display_info,
						 &lcd_info->bus_format, 1);
	connector->display_info.bus_flags = lcd_info->bus_flag;

	return num;
}

static const struct drm_panel_funcs lcd_olinuxino_funcs = {
	.disable = lcd_olinuxino_disable,
	.unprepare = lcd_olinuxino_unprepare,
	.prepare = lcd_olinuxino_prepare,
	.enable = lcd_olinuxino_enable,
	.get_modes = lcd_olinuxino_get_modes,
};

static int lcd_olinuxino_probe(struct i2c_client *client,
			       const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct lcd_olinuxino *lcd;
	u32 checksum, i;
	int ret = 0;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
		return -ENODEV;

	lcd = devm_kzalloc(dev, sizeof(*lcd), GFP_KERNEL);
	if (!lcd)
		return -ENOMEM;

	i2c_set_clientdata(client, lcd);
	lcd->dev = dev;
	lcd->client = client;

	mutex_init(&lcd->mutex);

	/* Copy data into buffer */
	for (i = 0; i < LCD_OLINUXINO_DATA_LEN; i += I2C_SMBUS_BLOCK_MAX) {
		mutex_lock(&lcd->mutex);
		ret = i2c_smbus_read_i2c_block_data(client,
						    i,
						    I2C_SMBUS_BLOCK_MAX,
						    (u8 *)&lcd->eeprom + i);
		mutex_unlock(&lcd->mutex);
		if (ret < 0) {
			dev_err(dev, "error reading from device at %02x\n", i);
			return ret;
		}
	}

	/* Check configuration checksum */
	checksum = ~crc32(~0, (u8 *)&lcd->eeprom, 252);
	if (checksum != lcd->eeprom.checksum) {
		dev_err(dev, "configuration checksum does not match!\n");
		return -EINVAL;
	}

	/* Check magic header */
	if (lcd->eeprom.header != LCD_OLINUXINO_HEADER_MAGIC) {
		dev_err(dev, "magic header does not match\n");
		return -EINVAL;
	}

	dev_info(dev, "Detected %s, Rev. %s, Serial: %08x\n",
		 lcd->eeprom.info.name,
		 lcd->eeprom.revision,
		 lcd->eeprom.serial);

	/*
	 * The eeprom can hold up to 4 modes.
	 * If the stored value is bigger, overwrite it.
	 */
	if (lcd->eeprom.num_modes > 4) {
		dev_warn(dev, "invalid number of modes, falling back to 4\n");
		lcd->eeprom.num_modes = 4;
	}

	lcd->enabled = false;
	lcd->prepared = false;

	lcd->supply = devm_regulator_get(dev, "power");
	if (IS_ERR(lcd->supply))
		return PTR_ERR(lcd->supply);

	lcd->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
	if (IS_ERR(lcd->enable_gpio))
		return PTR_ERR(lcd->enable_gpio);

	lcd->backlight = devm_of_find_backlight(dev);
	if (IS_ERR(lcd->backlight))
		return PTR_ERR(lcd->backlight);

	drm_panel_init(&lcd->panel);
	lcd->panel.dev = dev;
	lcd->panel.funcs = &lcd_olinuxino_funcs;

	return drm_panel_add(&lcd->panel);
}

static int lcd_olinuxino_remove(struct i2c_client *client)
{
	struct lcd_olinuxino *panel = i2c_get_clientdata(client);

	drm_panel_remove(&panel->panel);

	lcd_olinuxino_disable(&panel->panel);
	lcd_olinuxino_unprepare(&panel->panel);

	return 0;
}

static const struct of_device_id lcd_olinuxino_of_ids[] = {
	{ .compatible = "olimex,lcd-olinuxino" },
	{ }
};
MODULE_DEVICE_TABLE(of, lcd_olinuxino_of_ids);

static struct i2c_driver lcd_olinuxino_driver = {
	.driver = {
		.name = "lcd_olinuxino",
		.of_match_table = lcd_olinuxino_of_ids,
	},
	.probe = lcd_olinuxino_probe,
	.remove = lcd_olinuxino_remove,
};

module_i2c_driver(lcd_olinuxino_driver);

MODULE_AUTHOR("Stefan Mavrodiev <stefan@olimex.com>");
MODULE_DESCRIPTION("LCD-OLinuXino driver");
MODULE_LICENSE("GPL");