[PATCH] backlight: otm3225a: add support for ORISE OTM3225A LCD SoC
From: Felix Brack
Date: Wed Dec 20 2017 - 12:59:02 EST
This patch adds a LCD driver supporting the OTM3225A LCD SoC
from ORISE Technology. This device can drive TFT LC panels having a
resolution of 240x320 pixels. After initializing the OTM3225A using
it's SPI interface it switches to use 16-bib RGB as external
display interface.
Signed-off-by: Felix Brack <fb@xxxxxxx>
---
drivers/video/backlight/Kconfig | 7 ++
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/otm3225a.c | 210 +++++++++++++++++++++++++++++++++++++
3 files changed, 218 insertions(+)
create mode 100644 drivers/video/backlight/otm3225a.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 4e1d2ad..06e187b 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -150,6 +150,13 @@ config LCD_HX8357
If you have a HX-8357 LCD panel, say Y to enable its LCD control
driver.
+ config LCD_OTM3225A
+ tristate "ORISE Technology OTM3225A support"
+ depends on SPI
+ help
+ If you have a panel based on the OTM3225A controller
+ chip then say y to include a driver for it.
+
endif # LCD_CLASS_DEVICE
#
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 8905129..b177b91 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_LCD_S6E63M0) += s6e63m0.o
obj-$(CONFIG_LCD_TDO24M) += tdo24m.o
obj-$(CONFIG_LCD_TOSA) += tosa_lcd.o
obj-$(CONFIG_LCD_VGG2432A4) += vgg2432a4.o
+obj-$(CONFIG_LCD_OTM3225A) += otm3225a.o
obj-$(CONFIG_BACKLIGHT_88PM860X) += 88pm860x_bl.o
obj-$(CONFIG_BACKLIGHT_AAT2870) += aat2870_bl.o
diff --git a/drivers/video/backlight/otm3225a.c b/drivers/video/backlight/otm3225a.c
new file mode 100644
index 0000000..0de75f8
--- /dev/null
+++ b/drivers/video/backlight/otm3225a.c
@@ -0,0 +1,210 @@
+/*
+ * Driver for ORISE Technology OTM3225A SOC for TFT LCD
+ *
+ * Copyright (C) 2014-2017, EETS GmbH, Felix Brack <fb@xxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+
+ * This driver implements a lcd device for the ORISE OTM3225A display
+ * controller. The control interface to the display is SPI and the display's
+ * memory is updated over the 16-bit RGB interface.
+ * The main source of information for writing this driver was provided by the
+ * OTM3225A datasheet from ORISE Technology. Some information arise from the
+ * ILI9328 datasheet from ILITEK as well as from the datasheets and sample code
+ * provided by Crystalfontz America Inc. who sells the CFAF240320A-032T, a 3.2"
+ * TFT LC display using the OTM3225A controller.
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/lcd.h>
+#include <linux/spi/spi.h>
+
+#define OTM3225A_INDEX_REG 0x70
+#define OTM3225A_DATA_REG 0x72
+
+struct otm3225a_data {
+ struct spi_device *spi;
+ struct lcd_device *ld;
+ int power;
+};
+
+struct otm3225a_spi_instruction {
+ unsigned char reg; /* register to write */
+ unsigned short value; /* data to write to 'reg' */
+ unsigned short delay; /* delay in ms after write */
+};
+
+static struct otm3225a_spi_instruction display_init[] = {
+ { 0x01, 0x0000, 0 }, { 0x02, 0x0700, 0 }, { 0x03, 0x50A0, 0 },
+ { 0x04, 0x0000, 0 }, { 0x08, 0x0606, 0 }, { 0x09, 0x0000, 0 },
+ { 0x0A, 0x0000, 0 }, { 0x0C, 0x0000, 0 }, { 0x0D, 0x0000, 0 },
+ { 0x0F, 0x0002, 0 }, { 0x11, 0x0007, 0 }, { 0x12, 0x0000, 0 },
+ { 0x13, 0x0000, 200 }, { 0x07, 0x0101, 0 }, { 0x10, 0x12B0, 0 },
+ { 0x11, 0x0007, 0 }, { 0x12, 0x01BB, 50 }, { 0xB1, 0x0000, 0 },
+ { 0xB3, 0x0000, 0 }, { 0xB5, 0x0000, 0 }, { 0xBE, 0x0000, 0 },
+ { 0x13, 0x0013, 0 }, { 0x29, 0x0010, 50 }, { 0x30, 0x000A, 0 },
+ { 0x31, 0x1326, 0 }, { 0x32, 0x0A29, 0 }, { 0x35, 0x0A0A, 0 },
+ { 0x36, 0x1E03, 0 }, { 0x37, 0x031E, 0 }, { 0x38, 0x0706, 0 },
+ { 0x39, 0x0303, 0 }, { 0x3C, 0x010E, 0 }, { 0x3D, 0x040E, 0 },
+ { 0x50, 0x0000, 0 }, { 0x51, 0x00EF, 0 }, { 0x52, 0x0000, 0 },
+ { 0x53, 0x013F, 0 }, { 0x60, 0x2700, 0 }, { 0x61, 0x0001, 0 },
+ { 0x6A, 0x0000, 0 }, { 0x80, 0x0000, 0 }, { 0x81, 0x0000, 0 },
+ { 0x82, 0x0000, 0 }, { 0x83, 0x0000, 0 }, { 0x84, 0x0000, 0 },
+ { 0x85, 0x0000, 0 }, { 0x90, 0x0010, 0 }, { 0x92, 0x0000, 0 },
+ { 0x93, 0x0103, 0 }, { 0x95, 0x0210, 0 }, { 0x97, 0x0000, 0 },
+ { 0x98, 0x0000, 0 }, { 0x07, 0x0133, 0 },
+};
+
+static struct otm3225a_spi_instruction display_enable_rgb_interface[] = {
+ { 0x03, 0x1080, 0 },
+ { 0x20, 0x0000, 0 },
+ { 0x21, 0x0000, 0 },
+ { 0x0C, 0x0111, 500 },
+};
+
+static struct otm3225a_spi_instruction display_off[] = {
+ { 0x07, 0x0131, 100 },
+ { 0x07, 0x0130, 100 },
+ { 0x07, 0x0100, 0 },
+ { 0x10, 0x0280, 0 },
+ { 0x12, 0x018B, 0 },
+};
+
+static struct otm3225a_spi_instruction display_on[] = {
+ { 0x10, 0x1280, 0 },
+ { 0x07, 0x0101, 100 },
+ { 0x07, 0x0121, 0 },
+ { 0x07, 0x0123, 100 },
+ { 0x07, 0x0133, 10 },
+};
+
+static void otm3225a_write(struct spi_device *spi,
+ struct otm3225a_spi_instruction *instruction,
+ unsigned int count)
+{
+ unsigned char buf[3];
+
+ while (count--) {
+ /* address register using index register */
+ buf[0] = OTM3225A_INDEX_REG;
+ buf[1] = 0x00;
+ buf[2] = instruction->reg;
+ spi_write(spi, buf, 3);
+
+ /* write data to addressed register */
+ buf[0] = OTM3225A_DATA_REG;
+ buf[1] = (instruction->value >> 8) & 0xff;
+ buf[2] = instruction->value & 0xff;
+ spi_write(spi, buf, 3);
+
+ /* execute delay if any */
+ mdelay(instruction->delay);
+ instruction++;
+ }
+}
+
+static int otm3225a_set_power(struct lcd_device *ld, int power)
+{
+ struct otm3225a_data *dd = lcd_get_data(ld);
+
+ if (power == dd->power)
+ return 0;
+
+ if (power > FB_BLANK_UNBLANK)
+ otm3225a_write(dd->spi, display_off, ARRAY_SIZE(display_off));
+ else
+ otm3225a_write(dd->spi, display_on, ARRAY_SIZE(display_on));
+ dd->power = power;
+
+ return 0;
+}
+
+static int otm3225a_get_power(struct lcd_device *ld)
+{
+ struct otm3225a_data *dd = lcd_get_data(ld);
+
+ return dd->power;
+}
+
+struct lcd_ops otm3225a_ops = {
+ .set_power = otm3225a_set_power,
+ .get_power = otm3225a_get_power,
+};
+
+static int otm3225a_probe(struct spi_device *spi)
+{
+ struct otm3225a_data *dd;
+ struct lcd_device *ld;
+ int ret = 0;
+
+ dd = kzalloc(sizeof(struct otm3225a_data), GFP_KERNEL);
+ if (dd == NULL) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ ld = lcd_device_register("otm3225a", &spi->dev, dd, &otm3225a_ops);
+ if (IS_ERR(ld)) {
+ ret = PTR_ERR(ld);
+ goto err;
+ }
+ dd->spi = spi;
+ dd->ld = ld;
+ dev_set_drvdata(&spi->dev, dd);
+
+ dev_info(&spi->dev, "Initializing and switching to RGB interface");
+ otm3225a_write(spi, display_init, ARRAY_SIZE(display_init));
+ otm3225a_write(spi, display_enable_rgb_interface,
+ ARRAY_SIZE(display_enable_rgb_interface));
+
+err:
+ return ret;
+}
+
+static int otm3225a_remove(struct spi_device *spi)
+{
+ struct otm3225a_data *dd;
+
+ dd = dev_get_drvdata(&spi->dev);
+ lcd_device_unregister(dd->ld);
+ kfree(dd);
+ return 0;
+}
+
+static struct spi_driver otm3225a_driver = {
+ .driver = {
+ .name = "otm3225a",
+ .owner = THIS_MODULE,
+ },
+ .probe = otm3225a_probe,
+ .remove = otm3225a_remove,
+};
+
+static __init int otm3225a_init(void)
+{
+ return spi_register_driver(&otm3225a_driver);
+}
+
+static __exit void otm3225a_exit(void)
+{
+ spi_unregister_driver(&otm3225a_driver);
+}
+
+module_init(otm3225a_init);
+module_exit(otm3225a_exit);
+
+MODULE_AUTHOR("Felix Brack <fb@xxxxxxx>");
+MODULE_DESCRIPTION("OTM3225A TFT LCD driver");
+MODULE_VERSION("1.0.0");
+MODULE_LICENSE("GPL v2");
--
2.7.4