summaryrefslogtreecommitdiffstats
path: root/drivers/video/fbdev/amba-clcd-nomadik.c
blob: cd2db1113e67c2be2607c8440214ba2100d4e5f0 (plain) (blame)
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
#include <linux/amba/bus.h>
#include <linux/amba/clcd.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>

#include "amba-clcd-nomadik.h"

static struct gpio_desc *grestb;
static struct gpio_desc *scen;
static struct gpio_desc *scl;
static struct gpio_desc *sda;

static u8 tpg110_readwrite_reg(bool write, u8 address, u8 outval)
{
	int i;
	u8 inval = 0;

	/* Assert SCEN */
	gpiod_set_value_cansleep(scen, 1);
	ndelay(150);
	/* Hammer out the address */
	for (i = 5; i >= 0; i--) {
		if (address & BIT(i))
			gpiod_set_value_cansleep(sda, 1);
		else
			gpiod_set_value_cansleep(sda, 0);
		ndelay(150);
		/* Send an SCL pulse */
		gpiod_set_value_cansleep(scl, 1);
		ndelay(160);
		gpiod_set_value_cansleep(scl, 0);
		ndelay(160);
	}

	if (write) {
		/* WRITE */
		gpiod_set_value_cansleep(sda, 0);
	} else {
		/* READ */
		gpiod_set_value_cansleep(sda, 1);
	}
	ndelay(150);
	/* Send an SCL pulse */
	gpiod_set_value_cansleep(scl, 1);
	ndelay(160);
	gpiod_set_value_cansleep(scl, 0);
	ndelay(160);

	if (!write)
		/* HiZ turn-around cycle */
		gpiod_direction_input(sda);
	ndelay(150);
	/* Send an SCL pulse */
	gpiod_set_value_cansleep(scl, 1);
	ndelay(160);
	gpiod_set_value_cansleep(scl, 0);
	ndelay(160);

	/* Hammer in/out the data */
	for (i = 7; i >= 0; i--) {
		int value;

		if (write) {
			value = !!(outval & BIT(i));
			gpiod_set_value_cansleep(sda, value);
		} else {
			value = gpiod_get_value(sda);
			if (value)
				inval |= BIT(i);
		}
		ndelay(150);
		/* Send an SCL pulse */
		gpiod_set_value_cansleep(scl, 1);
		ndelay(160);
		gpiod_set_value_cansleep(scl, 0);
		ndelay(160);
	}

	gpiod_direction_output(sda, 0);
	/* Deassert SCEN */
	gpiod_set_value_cansleep(scen, 0);
	/* Satisfies SCEN pulse width */
	udelay(1);

	return inval;
}

static u8 tpg110_read_reg(u8 address)
{
	return tpg110_readwrite_reg(false, address, 0);
}

static void tpg110_write_reg(u8 address, u8 outval)
{
	tpg110_readwrite_reg(true, address, outval);
}

static void tpg110_startup(struct device *dev)
{
	u8 val;

	dev_info(dev, "TPG110 display enable\n");
	/* De-assert the reset signal */
	gpiod_set_value_cansleep(grestb, 0);
	mdelay(1);
	dev_info(dev, "de-asserted GRESTB\n");

	/* Test display communication */
	tpg110_write_reg(0x00, 0x55);
	val = tpg110_read_reg(0x00);
	if (val == 0x55)
		dev_info(dev, "passed communication test\n");
	val = tpg110_read_reg(0x01);
	dev_info(dev, "TPG110 chip ID: %d version: %d\n",
		val>>4, val&0x0f);

	/* Show display resolution */
	val = tpg110_read_reg(0x02);
	val &= 7;
	switch (val) {
	case 0x0:
		dev_info(dev, "IN 400x240 RGB -> OUT 800x480 RGB (dual scan)");
		break;
	case 0x1:
		dev_info(dev, "IN 480x272 RGB -> OUT 800x480 RGB (dual scan)");
		break;
	case 0x4:
		dev_info(dev, "480x640 RGB");
		break;
	case 0x5:
		dev_info(dev, "480x272 RGB");
		break;
	case 0x6:
		dev_info(dev, "640x480 RGB");
		break;
	case 0x7:
		dev_info(dev, "800x480 RGB");
		break;
	default:
		dev_info(dev, "ILLEGAL RESOLUTION");
		break;
	}

	val = tpg110_read_reg(0x03);
	dev_info(dev, "resolution is controlled by %s\n",
		(val & BIT(7)) ? "software" : "hardware");
}

static void tpg110_enable(struct clcd_fb *fb)
{
	struct device *dev = &fb->dev->dev;
	static bool startup;
	u8 val;

	if (!startup) {
		tpg110_startup(dev);
		startup = true;
	}

	/* Take chip out of standby */
	val = tpg110_read_reg(0x03);
	val |= BIT(0);
	tpg110_write_reg(0x03, val);
}

static void tpg110_disable(struct clcd_fb *fb)
{
	u8 val;

	dev_info(&fb->dev->dev, "TPG110 display disable\n");
	val = tpg110_read_reg(0x03);
	/* Put into standby */
	val &= ~BIT(0);
	tpg110_write_reg(0x03, val);
}

static void tpg110_init(struct device *dev, struct device_node *np,
			struct clcd_board *board)
{
	dev_info(dev, "TPG110 display init\n");

	/* This asserts the GRESTB signal, putting the display into reset */
	grestb = devm_fwnode_get_gpiod_from_child(dev, "grestb", &np->fwnode,
						  GPIOD_OUT_HIGH, "grestb");
	if (IS_ERR(grestb)) {
		dev_err(dev, "no GRESTB GPIO\n");
		return;
	}
	scen = devm_fwnode_get_gpiod_from_child(dev, "scen", &np->fwnode,
						GPIOD_OUT_LOW, "scen");
	if (IS_ERR(scen)) {
		dev_err(dev, "no SCEN GPIO\n");
		return;
	}
	scl = devm_fwnode_get_gpiod_from_child(dev, "scl", &np->fwnode,
					       GPIOD_OUT_LOW, "scl");
	if (IS_ERR(scl)) {
		dev_err(dev, "no SCL GPIO\n");
		return;
	}
	sda = devm_fwnode_get_gpiod_from_child(dev, "sda", &np->fwnode,
					       GPIOD_OUT_LOW, "sda");
	if (IS_ERR(sda)) {
		dev_err(dev, "no SDA GPIO\n");
		return;
	}
	board->enable = tpg110_enable;
	board->disable = tpg110_disable;
}

int nomadik_clcd_init_panel(struct clcd_fb *fb, struct device_node *panel)
{
	if (of_device_is_compatible(panel, "tpo,tpg110"))
		tpg110_init(&fb->dev->dev, panel, fb->board);
	else
		dev_info(&fb->dev->dev, "unknown panel\n");

	/* Unknown panel, fall through */
	return 0;
}
EXPORT_SYMBOL_GPL(nomadik_clcd_init_panel);

#define PMU_CTRL_OFFSET 0x0000
#define PMU_CTRL_LCDNDIF BIT(26)

int nomadik_clcd_init_board(struct amba_device *adev,
			    struct clcd_board *board)
{
	struct regmap *pmu_regmap;

	dev_info(&adev->dev, "Nomadik CLCD board init\n");
	pmu_regmap =
		syscon_regmap_lookup_by_compatible("stericsson,nomadik-pmu");
	if (IS_ERR(pmu_regmap)) {
		dev_err(&adev->dev, "could not find PMU syscon regmap\n");
		return PTR_ERR(pmu_regmap);
	}
	regmap_update_bits(pmu_regmap,
			   PMU_CTRL_OFFSET,
			   PMU_CTRL_LCDNDIF,
			   0);
	dev_info(&adev->dev, "set PMU mux to CLCD mode\n");

	return 0;
}
EXPORT_SYMBOL_GPL(nomadik_clcd_init_board);