video/backlight/l4f00242t03.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * l4f00242t03.c -- support for Epson L4F00242T03 LCD
0004  *
0005  * Copyright 2007-2009 Freescale Semiconductor, Inc. All Rights Reserved.
0006  *
0007  * Copyright (c) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
0008  *  Inspired by Marek Vasut work in l4f00242t03.c
0009  */
0010
0011 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0012
0013 #include <linux/device.h>
0014 #include <linux/kernel.h>
0015 #include <linux/delay.h>
0016 #include <linux/module.h>
0017 #include <linux/gpio/consumer.h>
0018 #include <linux/lcd.h>
0019 #include <linux/slab.h>
0020 #include <linux/regulator/consumer.h>
0021 #include <linux/spi/spi.h>
0022
0023 struct l4f00242t03_priv {
0024     struct spi_device   *spi;
0025     struct lcd_device   *ld;
0026     int lcd_state;
0027     struct regulator *io_reg;
0028     struct regulator *core_reg;
0029     struct gpio_desc *reset;
0030     struct gpio_desc *enable;
0031 };
0032
0033 static void l4f00242t03_reset(struct gpio_desc *gpiod)
0034 {
0035     pr_debug("l4f00242t03_reset.\n");
0036     gpiod_set_value(gpiod, 1);
0037     mdelay(100);
0038     gpiod_set_value(gpiod, 0);
0039     mdelay(10); /* tRES >= 100us */
0040     gpiod_set_value(gpiod, 1);
0041     mdelay(20);
0042 }
0043
0044 #define param(x) ((x) | 0x100)
0045
0046 static void l4f00242t03_lcd_init(struct spi_device *spi)
0047 {
0048     struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
0049     const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
0050     int ret;
0051
0052     dev_dbg(&spi->dev, "initializing LCD\n");
0053
0054     ret = regulator_set_voltage(priv->io_reg, 1800000, 1800000);
0055     if (ret) {
0056         dev_err(&spi->dev, "failed to set the IO regulator voltage.\n");
0057         return;
0058     }
0059     ret = regulator_enable(priv->io_reg);
0060     if (ret) {
0061         dev_err(&spi->dev, "failed to enable the IO regulator.\n");
0062         return;
0063     }
0064
0065     ret = regulator_set_voltage(priv->core_reg, 2800000, 2800000);
0066     if (ret) {
0067         dev_err(&spi->dev, "failed to set the core regulator voltage.\n");
0068         regulator_disable(priv->io_reg);
0069         return;
0070     }
0071     ret = regulator_enable(priv->core_reg);
0072     if (ret) {
0073         dev_err(&spi->dev, "failed to enable the core regulator.\n");
0074         regulator_disable(priv->io_reg);
0075         return;
0076     }
0077
0078     l4f00242t03_reset(priv->reset);
0079
0080     gpiod_set_value(priv->enable, 1);
0081     msleep(60);
0082     spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
0083 }
0084
0085 static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
0086 {
0087     struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
0088
0089     dev_dbg(&spi->dev, "Powering down LCD\n");
0090
0091     gpiod_set_value(priv->enable, 0);
0092
0093     regulator_disable(priv->io_reg);
0094     regulator_disable(priv->core_reg);
0095 }
0096
0097 static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
0098 {
0099     struct l4f00242t03_priv *priv = lcd_get_data(ld);
0100
0101     return priv->lcd_state;
0102 }
0103
0104 static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
0105 {
0106     struct l4f00242t03_priv *priv = lcd_get_data(ld);
0107     struct spi_device *spi = priv->spi;
0108
0109     const u16 slpout = 0x11;
0110     const u16 dison = 0x29;
0111
0112     const u16 slpin = 0x10;
0113     const u16 disoff = 0x28;
0114
0115     if (power <= FB_BLANK_NORMAL) {
0116         if (priv->lcd_state <= FB_BLANK_NORMAL) {
0117             /* Do nothing, the LCD is running */
0118         } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
0119             dev_dbg(&spi->dev, "Resuming LCD\n");
0120
0121             spi_write(spi, (const u8 *)&slpout, sizeof(u16));
0122             msleep(60);
0123             spi_write(spi, (const u8 *)&dison, sizeof(u16));
0124         } else {
0125             /* priv->lcd_state == FB_BLANK_POWERDOWN */
0126             l4f00242t03_lcd_init(spi);
0127             priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
0128             l4f00242t03_lcd_power_set(priv->ld, power);
0129         }
0130     } else if (power < FB_BLANK_POWERDOWN) {
0131         if (priv->lcd_state <= FB_BLANK_NORMAL) {
0132             /* Send the display in standby */
0133             dev_dbg(&spi->dev, "Standby the LCD\n");
0134
0135             spi_write(spi, (const u8 *)&disoff, sizeof(u16));
0136             msleep(60);
0137             spi_write(spi, (const u8 *)&slpin, sizeof(u16));
0138         } else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
0139             /* Do nothing, the LCD is already in standby */
0140         } else {
0141             /* priv->lcd_state == FB_BLANK_POWERDOWN */
0142             l4f00242t03_lcd_init(spi);
0143             priv->lcd_state = FB_BLANK_UNBLANK;
0144             l4f00242t03_lcd_power_set(ld, power);
0145         }
0146     } else {
0147         /* power == FB_BLANK_POWERDOWN */
0148         if (priv->lcd_state != FB_BLANK_POWERDOWN) {
0149             /* Clear the screen before shutting down */
0150             spi_write(spi, (const u8 *)&disoff, sizeof(u16));
0151             msleep(60);
0152             l4f00242t03_lcd_powerdown(spi);
0153         }
0154     }
0155
0156     priv->lcd_state = power;
0157
0158     return 0;
0159 }
0160
0161 static struct lcd_ops l4f_ops = {
0162     .set_power  = l4f00242t03_lcd_power_set,
0163     .get_power  = l4f00242t03_lcd_power_get,
0164 };
0165
0166 static int l4f00242t03_probe(struct spi_device *spi)
0167 {
0168     struct l4f00242t03_priv *priv;
0169
0170     priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
0171                 GFP_KERNEL);
0172     if (priv == NULL)
0173         return -ENOMEM;
0174
0175     spi_set_drvdata(spi, priv);
0176     spi->bits_per_word = 9;
0177     spi_setup(spi);
0178
0179     priv->spi = spi;
0180
0181     priv->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
0182     if (IS_ERR(priv->reset)) {
0183         dev_err(&spi->dev,
0184             "Unable to get the lcd l4f00242t03 reset gpio.\n");
0185         return PTR_ERR(priv->reset);
0186     }
0187     gpiod_set_consumer_name(priv->reset, "lcd l4f00242t03 reset");
0188
0189     priv->enable = devm_gpiod_get(&spi->dev, "enable", GPIOD_OUT_LOW);
0190     if (IS_ERR(priv->enable)) {
0191         dev_err(&spi->dev,
0192             "Unable to get the lcd l4f00242t03 data en gpio.\n");
0193         return PTR_ERR(priv->enable);
0194     }
0195     gpiod_set_consumer_name(priv->enable, "lcd l4f00242t03 data enable");
0196
0197     priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
0198     if (IS_ERR(priv->io_reg)) {
0199         dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
0200                __func__);
0201         return PTR_ERR(priv->io_reg);
0202     }
0203
0204     priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
0205     if (IS_ERR(priv->core_reg)) {
0206         dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
0207                __func__);
0208         return PTR_ERR(priv->core_reg);
0209     }
0210
0211     priv->ld = devm_lcd_device_register(&spi->dev, "l4f00242t03", &spi->dev,
0212                     priv, &l4f_ops);
0213     if (IS_ERR(priv->ld))
0214         return PTR_ERR(priv->ld);
0215
0216     /* Init the LCD */
0217     l4f00242t03_lcd_init(spi);
0218     priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
0219     l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
0220
0221     dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
0222
0223     return 0;
0224 }
0225
0226 static void l4f00242t03_remove(struct spi_device *spi)
0227 {
0228     struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
0229
0230     l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
0231 }
0232
0233 static void l4f00242t03_shutdown(struct spi_device *spi)
0234 {
0235     struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
0236
0237     if (priv)
0238         l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
0239
0240 }
0241
0242 static struct spi_driver l4f00242t03_driver = {
0243     .driver = {
0244         .name   = "l4f00242t03",
0245     },
0246     .probe      = l4f00242t03_probe,
0247     .remove     = l4f00242t03_remove,
0248     .shutdown   = l4f00242t03_shutdown,
0249 };
0250
0251 module_spi_driver(l4f00242t03_driver);
0252
0253 MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
0254 MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
0255 MODULE_LICENSE("GPL v2");