l4f00242t03.c

  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
 23struct 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
 33static 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
 46static 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
 85static 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
 97static 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
104static 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 <= LCD_POWER_REDUCED) {
116		if (priv->lcd_state <= LCD_POWER_REDUCED) {
117			/* Do nothing, the LCD is running */
118		} else if (priv->lcd_state < LCD_POWER_OFF) {
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 == LCD_POWER_OFF */
126			l4f00242t03_lcd_init(spi);
127			priv->lcd_state = LCD_POWER_REDUCED_VSYNC_SUSPEND;
128			l4f00242t03_lcd_power_set(priv->ld, power);
129		}
130	} else if (power < LCD_POWER_OFF) {
131		if (priv->lcd_state <= LCD_POWER_REDUCED) {
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 < LCD_POWER_OFF) {
139			/* Do nothing, the LCD is already in standby */
140		} else {
141			/* priv->lcd_state == LCD_POWER_OFF */
142			l4f00242t03_lcd_init(spi);
143			priv->lcd_state = LCD_POWER_ON;
144			l4f00242t03_lcd_power_set(ld, power);
145		}
146	} else {
147		/* power == LCD_POWER_OFF */
148		if (priv->lcd_state != LCD_POWER_OFF) {
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
161static const struct lcd_ops l4f_ops = {
162	.set_power	= l4f00242t03_lcd_power_set,
163	.get_power	= l4f00242t03_lcd_power_get,
164};
165
166static int l4f00242t03_probe(struct spi_device *spi)
167{
168	struct l4f00242t03_priv *priv;
169	int ret;
170
171	priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
172				GFP_KERNEL);
173	if (priv == NULL)
174		return -ENOMEM;
175
176	spi_set_drvdata(spi, priv);
177	spi->bits_per_word = 9;
178	ret = spi_setup(spi);
179	if (ret < 0)
180		return dev_err_probe(&spi->dev, ret, "Unable to setup spi.\n");
181
182	priv->spi = spi;
183
184	priv->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
185	if (IS_ERR(priv->reset))
186		return dev_err_probe(&spi->dev, PTR_ERR(priv->reset),
187				     "Unable to get the lcd l4f00242t03 reset gpio.\n");
188	gpiod_set_consumer_name(priv->reset, "lcd l4f00242t03 reset");
189
190	priv->enable = devm_gpiod_get(&spi->dev, "enable", GPIOD_OUT_LOW);
191	if (IS_ERR(priv->enable))
192		return dev_err_probe(&spi->dev, PTR_ERR(priv->enable),
193				     "Unable to get the lcd l4f00242t03 data en gpio.\n");
194	gpiod_set_consumer_name(priv->enable, "lcd l4f00242t03 data enable");
195
196	priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
197	if (IS_ERR(priv->io_reg))
198		return dev_err_probe(&spi->dev, PTR_ERR(priv->io_reg),
199				     "%s: Unable to get the IO regulator\n",
200				     __func__);
201
202	priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
203	if (IS_ERR(priv->core_reg))
204		return dev_err_probe(&spi->dev, PTR_ERR(priv->core_reg),
205				     "%s: Unable to get the core regulator\n",
206				     __func__);
207
208	priv->ld = devm_lcd_device_register(&spi->dev, "l4f00242t03", &spi->dev,
209					priv, &l4f_ops);
210	if (IS_ERR(priv->ld))
211		return PTR_ERR(priv->ld);
212
213	/* Init the LCD */
214	l4f00242t03_lcd_init(spi);
215	priv->lcd_state = LCD_POWER_REDUCED_VSYNC_SUSPEND;
216	l4f00242t03_lcd_power_set(priv->ld, LCD_POWER_ON);
217
218	dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
219
220	return 0;
221}
222
223static void l4f00242t03_remove(struct spi_device *spi)
224{
225	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
226
227	l4f00242t03_lcd_power_set(priv->ld, LCD_POWER_OFF);
228}
229
230static void l4f00242t03_shutdown(struct spi_device *spi)
231{
232	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
233
234	if (priv)
235		l4f00242t03_lcd_power_set(priv->ld, LCD_POWER_OFF);
236
237}
238
239static struct spi_driver l4f00242t03_driver = {
240	.driver = {
241		.name	= "l4f00242t03",
242	},
243	.probe		= l4f00242t03_probe,
244	.remove		= l4f00242t03_remove,
245	.shutdown	= l4f00242t03_shutdown,
246};
247
248module_spi_driver(l4f00242t03_driver);
249
250MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
251MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
252MODULE_LICENSE("GPL v2");