1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * l4f00242t03.c -- support for Epson L4F00242T03 LCD
4  *
5  * Copyright 2007-2009 Freescale Semiconductor, Inc. All Rights Reserved.
6  *
7  * Copyright (c) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
8  *	Inspired by Marek Vasut work in l4f00242t03.c
9  */
10 
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/device.h>
14 #include <linux/kernel.h>
15 #include <linux/delay.h>
16 #include <linux/module.h>
17 #include <linux/gpio/consumer.h>
18 #include <linux/lcd.h>
19 #include <linux/slab.h>
20 #include <linux/regulator/consumer.h>
21 #include <linux/spi/spi.h>
22 
23 struct l4f00242t03_priv {
24 	struct spi_device	*spi;
25 	struct lcd_device	*ld;
26 	int lcd_state;
27 	struct regulator *io_reg;
28 	struct regulator *core_reg;
29 	struct gpio_desc *reset;
30 	struct gpio_desc *enable;
31 };
32 
l4f00242t03_reset(struct gpio_desc * gpiod)33 static void l4f00242t03_reset(struct gpio_desc *gpiod)
34 {
35 	pr_debug("l4f00242t03_reset.\n");
36 	gpiod_set_value(gpiod, 1);
37 	mdelay(100);
38 	gpiod_set_value(gpiod, 0);
39 	mdelay(10);	/* tRES >= 100us */
40 	gpiod_set_value(gpiod, 1);
41 	mdelay(20);
42 }
43 
44 #define param(x) ((x) | 0x100)
45 
l4f00242t03_lcd_init(struct spi_device * spi)46 static void l4f00242t03_lcd_init(struct spi_device *spi)
47 {
48 	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
49 	const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
50 	int ret;
51 
52 	dev_dbg(&spi->dev, "initializing LCD\n");
53 
54 	ret = regulator_set_voltage(priv->io_reg, 1800000, 1800000);
55 	if (ret) {
56 		dev_err(&spi->dev, "failed to set the IO regulator voltage.\n");
57 		return;
58 	}
59 	ret = regulator_enable(priv->io_reg);
60 	if (ret) {
61 		dev_err(&spi->dev, "failed to enable the IO regulator.\n");
62 		return;
63 	}
64 
65 	ret = regulator_set_voltage(priv->core_reg, 2800000, 2800000);
66 	if (ret) {
67 		dev_err(&spi->dev, "failed to set the core regulator voltage.\n");
68 		regulator_disable(priv->io_reg);
69 		return;
70 	}
71 	ret = regulator_enable(priv->core_reg);
72 	if (ret) {
73 		dev_err(&spi->dev, "failed to enable the core regulator.\n");
74 		regulator_disable(priv->io_reg);
75 		return;
76 	}
77 
78 	l4f00242t03_reset(priv->reset);
79 
80 	gpiod_set_value(priv->enable, 1);
81 	msleep(60);
82 	spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
83 }
84 
l4f00242t03_lcd_powerdown(struct spi_device * spi)85 static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
86 {
87 	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
88 
89 	dev_dbg(&spi->dev, "Powering down LCD\n");
90 
91 	gpiod_set_value(priv->enable, 0);
92 
93 	regulator_disable(priv->io_reg);
94 	regulator_disable(priv->core_reg);
95 }
96 
l4f00242t03_lcd_power_get(struct lcd_device * ld)97 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
98 {
99 	struct l4f00242t03_priv *priv = lcd_get_data(ld);
100 
101 	return priv->lcd_state;
102 }
103 
l4f00242t03_lcd_power_set(struct lcd_device * ld,int power)104 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
105 {
106 	struct l4f00242t03_priv *priv = lcd_get_data(ld);
107 	struct spi_device *spi = priv->spi;
108 
109 	const u16 slpout = 0x11;
110 	const u16 dison = 0x29;
111 
112 	const u16 slpin = 0x10;
113 	const u16 disoff = 0x28;
114 
115 	if (power <= FB_BLANK_NORMAL) {
116 		if (priv->lcd_state <= FB_BLANK_NORMAL) {
117 			/* Do nothing, the LCD is running */
118 		} else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
119 			dev_dbg(&spi->dev, "Resuming LCD\n");
120 
121 			spi_write(spi, (const u8 *)&slpout, sizeof(u16));
122 			msleep(60);
123 			spi_write(spi, (const u8 *)&dison, sizeof(u16));
124 		} else {
125 			/* priv->lcd_state == FB_BLANK_POWERDOWN */
126 			l4f00242t03_lcd_init(spi);
127 			priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
128 			l4f00242t03_lcd_power_set(priv->ld, power);
129 		}
130 	} else if (power < FB_BLANK_POWERDOWN) {
131 		if (priv->lcd_state <= FB_BLANK_NORMAL) {
132 			/* Send the display in standby */
133 			dev_dbg(&spi->dev, "Standby the LCD\n");
134 
135 			spi_write(spi, (const u8 *)&disoff, sizeof(u16));
136 			msleep(60);
137 			spi_write(spi, (const u8 *)&slpin, sizeof(u16));
138 		} else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
139 			/* Do nothing, the LCD is already in standby */
140 		} else {
141 			/* priv->lcd_state == FB_BLANK_POWERDOWN */
142 			l4f00242t03_lcd_init(spi);
143 			priv->lcd_state = FB_BLANK_UNBLANK;
144 			l4f00242t03_lcd_power_set(ld, power);
145 		}
146 	} else {
147 		/* power == FB_BLANK_POWERDOWN */
148 		if (priv->lcd_state != FB_BLANK_POWERDOWN) {
149 			/* Clear the screen before shutting down */
150 			spi_write(spi, (const u8 *)&disoff, sizeof(u16));
151 			msleep(60);
152 			l4f00242t03_lcd_powerdown(spi);
153 		}
154 	}
155 
156 	priv->lcd_state = power;
157 
158 	return 0;
159 }
160 
161 static struct lcd_ops l4f_ops = {
162 	.set_power	= l4f00242t03_lcd_power_set,
163 	.get_power	= l4f00242t03_lcd_power_get,
164 };
165 
l4f00242t03_probe(struct spi_device * spi)166 static int l4f00242t03_probe(struct spi_device *spi)
167 {
168 	struct l4f00242t03_priv *priv;
169 
170 	priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
171 				GFP_KERNEL);
172 	if (priv == NULL)
173 		return -ENOMEM;
174 
175 	spi_set_drvdata(spi, priv);
176 	spi->bits_per_word = 9;
177 	spi_setup(spi);
178 
179 	priv->spi = spi;
180 
181 	priv->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
182 	if (IS_ERR(priv->reset)) {
183 		dev_err(&spi->dev,
184 			"Unable to get the lcd l4f00242t03 reset gpio.\n");
185 		return PTR_ERR(priv->reset);
186 	}
187 	gpiod_set_consumer_name(priv->reset, "lcd l4f00242t03 reset");
188 
189 	priv->enable = devm_gpiod_get(&spi->dev, "enable", GPIOD_OUT_LOW);
190 	if (IS_ERR(priv->enable)) {
191 		dev_err(&spi->dev,
192 			"Unable to get the lcd l4f00242t03 data en gpio.\n");
193 		return PTR_ERR(priv->enable);
194 	}
195 	gpiod_set_consumer_name(priv->enable, "lcd l4f00242t03 data enable");
196 
197 	priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
198 	if (IS_ERR(priv->io_reg)) {
199 		dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
200 		       __func__);
201 		return PTR_ERR(priv->io_reg);
202 	}
203 
204 	priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
205 	if (IS_ERR(priv->core_reg)) {
206 		dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
207 		       __func__);
208 		return PTR_ERR(priv->core_reg);
209 	}
210 
211 	priv->ld = devm_lcd_device_register(&spi->dev, "l4f00242t03", &spi->dev,
212 					priv, &l4f_ops);
213 	if (IS_ERR(priv->ld))
214 		return PTR_ERR(priv->ld);
215 
216 	/* Init the LCD */
217 	l4f00242t03_lcd_init(spi);
218 	priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
219 	l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
220 
221 	dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
222 
223 	return 0;
224 }
225 
l4f00242t03_remove(struct spi_device * spi)226 static void l4f00242t03_remove(struct spi_device *spi)
227 {
228 	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
229 
230 	l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
231 }
232 
l4f00242t03_shutdown(struct spi_device * spi)233 static void l4f00242t03_shutdown(struct spi_device *spi)
234 {
235 	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
236 
237 	if (priv)
238 		l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
239 
240 }
241 
242 static struct spi_driver l4f00242t03_driver = {
243 	.driver = {
244 		.name	= "l4f00242t03",
245 	},
246 	.probe		= l4f00242t03_probe,
247 	.remove		= l4f00242t03_remove,
248 	.shutdown	= l4f00242t03_shutdown,
249 };
250 
251 module_spi_driver(l4f00242t03_driver);
252 
253 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
254 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
255 MODULE_LICENSE("GPL v2");
256