diff options
Diffstat (limited to 'drivers/video/backlight/otm3225a.c')
| -rw-r--r-- | drivers/video/backlight/otm3225a.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/drivers/video/backlight/otm3225a.c b/drivers/video/backlight/otm3225a.c new file mode 100644 index 000000000..2472e2167 --- /dev/null +++ b/drivers/video/backlight/otm3225a.c @@ -0,0 +1,252 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Driver for ORISE Technology OTM3225A SOC for TFT LCD + * Copyright (C) 2017, EETS GmbH, Felix Brack <fb@ltec.ch> + * + * 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/delay.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/lcd.h> +#include <linux/module.h> +#include <linux/spi/spi.h> + +#define OTM3225A_INDEX_REG 0x70 +#define OTM3225A_DATA_REG 0x72 + +/* instruction register list */ +#define DRIVER_OUTPUT_CTRL_1 0x01 +#define DRIVER_WAVEFORM_CTRL 0x02 +#define ENTRY_MODE 0x03 +#define SCALING_CTRL 0x04 +#define DISPLAY_CTRL_1 0x07 +#define DISPLAY_CTRL_2 0x08 +#define DISPLAY_CTRL_3 0x09 +#define FRAME_CYCLE_CTRL 0x0A +#define EXT_DISP_IFACE_CTRL_1 0x0C +#define FRAME_MAKER_POS 0x0D +#define EXT_DISP_IFACE_CTRL_2 0x0F +#define POWER_CTRL_1 0x10 +#define POWER_CTRL_2 0x11 +#define POWER_CTRL_3 0x12 +#define POWER_CTRL_4 0x13 +#define GRAM_ADDR_HORIZ_SET 0x20 +#define GRAM_ADDR_VERT_SET 0x21 +#define GRAM_READ_WRITE 0x22 +#define POWER_CTRL_7 0x29 +#define FRAME_RATE_CTRL 0x2B +#define GAMMA_CTRL_1 0x30 +#define GAMMA_CTRL_2 0x31 +#define GAMMA_CTRL_3 0x32 +#define GAMMA_CTRL_4 0x35 +#define GAMMA_CTRL_5 0x36 +#define GAMMA_CTRL_6 0x37 +#define GAMMA_CTRL_7 0x38 +#define GAMMA_CTRL_8 0x39 +#define GAMMA_CTRL_9 0x3C +#define GAMMA_CTRL_10 0x3D +#define WINDOW_HORIZ_RAM_START 0x50 +#define WINDOW_HORIZ_RAM_END 0x51 +#define WINDOW_VERT_RAM_START 0x52 +#define WINDOW_VERT_RAM_END 0x53 +#define DRIVER_OUTPUT_CTRL_2 0x60 +#define BASE_IMG_DISPLAY_CTRL 0x61 +#define VERT_SCROLL_CTRL 0x6A +#define PD1_DISPLAY_POS 0x80 +#define PD1_RAM_START 0x81 +#define PD1_RAM_END 0x82 +#define PD2_DISPLAY_POS 0x83 +#define PD2_RAM_START 0x84 +#define PD2_RAM_END 0x85 +#define PANEL_IFACE_CTRL_1 0x90 +#define PANEL_IFACE_CTRL_2 0x92 +#define PANEL_IFACE_CTRL_4 0x95 +#define PANEL_IFACE_CTRL_5 0x97 + +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[] = { + { DRIVER_OUTPUT_CTRL_1, 0x0000, 0 }, + { DRIVER_WAVEFORM_CTRL, 0x0700, 0 }, + { ENTRY_MODE, 0x50A0, 0 }, + { SCALING_CTRL, 0x0000, 0 }, + { DISPLAY_CTRL_2, 0x0606, 0 }, + { DISPLAY_CTRL_3, 0x0000, 0 }, + { FRAME_CYCLE_CTRL, 0x0000, 0 }, + { EXT_DISP_IFACE_CTRL_1, 0x0000, 0 }, + { FRAME_MAKER_POS, 0x0000, 0 }, + { EXT_DISP_IFACE_CTRL_2, 0x0002, 0 }, + { POWER_CTRL_2, 0x0007, 0 }, + { POWER_CTRL_3, 0x0000, 0 }, + { POWER_CTRL_4, 0x0000, 200 }, + { DISPLAY_CTRL_1, 0x0101, 0 }, + { POWER_CTRL_1, 0x12B0, 0 }, + { POWER_CTRL_2, 0x0007, 0 }, + { POWER_CTRL_3, 0x01BB, 50 }, + { POWER_CTRL_4, 0x0013, 0 }, + { POWER_CTRL_7, 0x0010, 50 }, + { GAMMA_CTRL_1, 0x000A, 0 }, + { GAMMA_CTRL_2, 0x1326, 0 }, + { GAMMA_CTRL_3, 0x0A29, 0 }, + { GAMMA_CTRL_4, 0x0A0A, 0 }, + { GAMMA_CTRL_5, 0x1E03, 0 }, + { GAMMA_CTRL_6, 0x031E, 0 }, + { GAMMA_CTRL_7, 0x0706, 0 }, + { GAMMA_CTRL_8, 0x0303, 0 }, + { GAMMA_CTRL_9, 0x010E, 0 }, + { GAMMA_CTRL_10, 0x040E, 0 }, + { WINDOW_HORIZ_RAM_START, 0x0000, 0 }, + { WINDOW_HORIZ_RAM_END, 0x00EF, 0 }, + { WINDOW_VERT_RAM_START, 0x0000, 0 }, + { WINDOW_VERT_RAM_END, 0x013F, 0 }, + { DRIVER_OUTPUT_CTRL_2, 0x2700, 0 }, + { BASE_IMG_DISPLAY_CTRL, 0x0001, 0 }, + { VERT_SCROLL_CTRL, 0x0000, 0 }, + { PD1_DISPLAY_POS, 0x0000, 0 }, + { PD1_RAM_START, 0x0000, 0 }, + { PD1_RAM_END, 0x0000, 0 }, + { PD2_DISPLAY_POS, 0x0000, 0 }, + { PD2_RAM_START, 0x0000, 0 }, + { PD2_RAM_END, 0x0000, 0 }, + { PANEL_IFACE_CTRL_1, 0x0010, 0 }, + { PANEL_IFACE_CTRL_2, 0x0000, 0 }, + { PANEL_IFACE_CTRL_4, 0x0210, 0 }, + { PANEL_IFACE_CTRL_5, 0x0000, 0 }, + { DISPLAY_CTRL_1, 0x0133, 0 }, +}; + +static struct otm3225a_spi_instruction display_enable_rgb_interface[] = { + { ENTRY_MODE, 0x1080, 0 }, + { GRAM_ADDR_HORIZ_SET, 0x0000, 0 }, + { GRAM_ADDR_VERT_SET, 0x0000, 0 }, + { EXT_DISP_IFACE_CTRL_1, 0x0111, 500 }, +}; + +static struct otm3225a_spi_instruction display_off[] = { + { DISPLAY_CTRL_1, 0x0131, 100 }, + { DISPLAY_CTRL_1, 0x0130, 100 }, + { DISPLAY_CTRL_1, 0x0100, 0 }, + { POWER_CTRL_1, 0x0280, 0 }, + { POWER_CTRL_3, 0x018B, 0 }, +}; + +static struct otm3225a_spi_instruction display_on[] = { + { POWER_CTRL_1, 0x1280, 0 }, + { DISPLAY_CTRL_1, 0x0101, 100 }, + { DISPLAY_CTRL_1, 0x0121, 0 }, + { DISPLAY_CTRL_1, 0x0123, 100 }, + { DISPLAY_CTRL_1, 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 */ + if (instruction->delay) + msleep(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; +} + +static 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; + struct device *dev = &spi->dev; + + dd = devm_kzalloc(dev, sizeof(struct otm3225a_data), GFP_KERNEL); + if (dd == NULL) + return -ENOMEM; + + ld = devm_lcd_device_register(dev, dev_name(dev), dev, dd, + &otm3225a_ops); + if (IS_ERR(ld)) + return PTR_ERR(ld); + + dd->spi = spi; + dd->ld = ld; + dev_set_drvdata(dev, dd); + + dev_info(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)); + return 0; +} + +static struct spi_driver otm3225a_driver = { + .driver = { + .name = "otm3225a", + .owner = THIS_MODULE, + }, + .probe = otm3225a_probe, +}; + +module_spi_driver(otm3225a_driver); + +MODULE_AUTHOR("Felix Brack <fb@ltec.ch>"); +MODULE_DESCRIPTION("OTM3225A TFT LCD driver"); +MODULE_VERSION("1.0.0"); +MODULE_LICENSE("GPL v2"); |