// SPDX-License-Identifier: GPL-2.0-or-later /* * (C) Copyright 2008 * Stefano Babic, DENX Software Engineering, [email protected]. * * This driver implements a lcd device for the ILITEK 922x display * controller. The interface to the display is SPI and the display's * memory is cyclically updated over the RGB interface. */ #include <linux/fb.h> #include <linux/delay.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/lcd.h> #include <linux/module.h> #include <linux/of.h> #include <linux/slab.h> #include <linux/spi/spi.h> #include <linux/string.h> /* Register offset, see manual section 8.2 */ #define REG_START_OSCILLATION … #define REG_DRIVER_CODE_READ … #define REG_DRIVER_OUTPUT_CONTROL … #define REG_LCD_AC_DRIVEING_CONTROL … #define REG_ENTRY_MODE … #define REG_COMPARE_1 … #define REG_COMPARE_2 … #define REG_DISPLAY_CONTROL_1 … #define REG_DISPLAY_CONTROL_2 … #define REG_DISPLAY_CONTROL_3 … #define REG_FRAME_CYCLE_CONTROL … #define REG_EXT_INTF_CONTROL … #define REG_POWER_CONTROL_1 … #define REG_POWER_CONTROL_2 … #define REG_POWER_CONTROL_3 … #define REG_POWER_CONTROL_4 … #define REG_RAM_ADDRESS_SET … #define REG_WRITE_DATA_TO_GRAM … #define REG_RAM_WRITE_MASK1 … #define REG_RAM_WRITE_MASK2 … #define REG_GAMMA_CONTROL_1 … #define REG_GAMMA_CONTROL_2 … #define REG_GAMMA_CONTROL_3 … #define REG_GAMMA_CONTROL_4 … #define REG_GAMMA_CONTROL_5 … #define REG_GAMMA_CONTROL_6 … #define REG_GAMMA_CONTROL_7 … #define REG_GAMMA_CONTROL_8 … #define REG_GAMMA_CONTROL_9 … #define REG_GAMMA_CONTROL_10 … #define REG_GATE_SCAN_CONTROL … #define REG_VERT_SCROLL_CONTROL … #define REG_FIRST_SCREEN_DRIVE_POS … #define REG_SECOND_SCREEN_DRIVE_POS … #define REG_RAM_ADDR_POS_H … #define REG_RAM_ADDR_POS_V … #define REG_OSCILLATOR_CONTROL … #define REG_GPIO … #define REG_OTP_VCM_PROGRAMMING … #define REG_OTP_VCM_STATUS_ENABLE … #define REG_OTP_PROGRAMMING_ID_KEY … /* * maximum frequency for register access * (not for the GRAM access) */ #define ILITEK_MAX_FREQ_REG … /* * Device ID as found in the datasheet (supports 9221 and 9222) */ #define ILITEK_DEVICE_ID … #define ILITEK_DEVICE_ID_MASK … /* Last two bits in the START BYTE */ #define START_RS_INDEX … #define START_RS_REG … #define START_RW_WRITE … #define START_RW_READ … /* * START_BYTE(id, rs, rw) * * Set the start byte according to the required operation. * The start byte is defined as: * ---------------------------------- * | 0 | 1 | 1 | 1 | 0 | ID | RS | RW | * ---------------------------------- * @id: display's id as set by the manufacturer * @rs: operation type bit, one of: * - START_RS_INDEX set the index register * - START_RS_REG write/read registers/GRAM * @rw: read/write operation * - START_RW_WRITE write * - START_RW_READ read */ #define START_BYTE(id, rs, rw) … /* * CHECK_FREQ_REG(spi_device s, spi_transfer x) - Check the frequency * for the SPI transfer. According to the datasheet, the controller * accept higher frequency for the GRAM transfer, but it requires * lower frequency when the registers are read/written. * The macro sets the frequency in the spi_transfer structure if * the frequency exceeds the maximum value. * @s: pointer to an SPI device * @x: pointer to the read/write buffer pair */ #define CHECK_FREQ_REG(s, x) … #define CMD_BUFSIZE … #define POWER_IS_ON(pwr) … #define set_tx_byte(b) … /* * ili922x_id - id as set by manufacturer */ static int ili922x_id = …; module_param(ili922x_id, int, 0); static int tx_invert; module_param(tx_invert, int, 0); /* * driver's private structure */ struct ili922x { … }; /** * ili922x_read_status - read status register from display * @spi: spi device * @rs: output value */ static int ili922x_read_status(struct spi_device *spi, u16 *rs) { … } /** * ili922x_read - read register from display * @spi: spi device * @reg: offset of the register to be read * @rx: output value */ static int ili922x_read(struct spi_device *spi, u8 reg, u16 *rx) { … } /** * ili922x_write - write a controller register * @spi: struct spi_device * * @reg: offset of the register to be written * @value: value to be written */ static int ili922x_write(struct spi_device *spi, u8 reg, u16 value) { … } #ifdef DEBUG /** * ili922x_reg_dump - dump all registers * * @spi: pointer to an SPI device */ static void ili922x_reg_dump(struct spi_device *spi) { u8 reg; u16 rx; dev_dbg(&spi->dev, "ILI922x configuration registers:\n"); for (reg = REG_START_OSCILLATION; reg <= REG_OTP_PROGRAMMING_ID_KEY; reg++) { ili922x_read(spi, reg, &rx); dev_dbg(&spi->dev, "reg @ 0x%02X: 0x%04X\n", reg, rx); } } #else static inline void ili922x_reg_dump(struct spi_device *spi) { … } #endif /** * set_write_to_gram_reg - initialize the display to write the GRAM * @spi: spi device */ static void set_write_to_gram_reg(struct spi_device *spi) { … } /** * ili922x_poweron - turn the display on * @spi: spi device * * The sequence to turn on the display is taken from * the datasheet and/or the example code provided by the * manufacturer. */ static int ili922x_poweron(struct spi_device *spi) { … } /** * ili922x_poweroff - turn the display off * @spi: spi device */ static int ili922x_poweroff(struct spi_device *spi) { … } /** * ili922x_display_init - initialize the display by setting * the configuration registers * @spi: spi device */ static void ili922x_display_init(struct spi_device *spi) { … } static int ili922x_lcd_power(struct ili922x *lcd, int power) { … } static int ili922x_set_power(struct lcd_device *ld, int power) { … } static int ili922x_get_power(struct lcd_device *ld) { … } static const struct lcd_ops ili922x_ops = …; static int ili922x_probe(struct spi_device *spi) { … } static void ili922x_remove(struct spi_device *spi) { … } static struct spi_driver ili922x_driver = …; module_spi_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; MODULE_PARM_DESC(…) …; MODULE_PARM_DESC(…) …;
Codebase Browser
linux