--- /dev/null
+/*
+ * (C) Copyright 2008
+ * Stefano Babic, DENX Software Engineering, sbabic@denx.de.
+ *
+ * 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 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 0x00
+#define REG_DRIVER_CODE_READ 0x00
+#define REG_DRIVER_OUTPUT_CONTROL 0x01
+#define REG_LCD_AC_DRIVEING_CONTROL 0x02
+#define REG_ENTRY_MODE 0x03
+#define REG_COMPARE_1 0x04
+#define REG_COMPARE_2 0x05
+#define REG_DISPLAY_CONTROL_1 0x07
+#define REG_DISPLAY_CONTROL_2 0x08
+#define REG_DISPLAY_CONTROL_3 0x09
+#define REG_FRAME_CYCLE_CONTROL 0x0B
+#define REG_EXT_INTF_CONTROL 0x0C
+#define REG_POWER_CONTROL_1 0x10
+#define REG_POWER_CONTROL_2 0x11
+#define REG_POWER_CONTROL_3 0x12
+#define REG_POWER_CONTROL_4 0x13
+#define REG_RAM_ADDRESS_SET 0x21
+#define REG_WRITE_DATA_TO_GRAM 0x22
+#define REG_RAM_WRITE_MASK1 0x23
+#define REG_RAM_WRITE_MASK2 0x24
+#define REG_GAMMA_CONTROL_1 0x30
+#define REG_GAMMA_CONTROL_2 0x31
+#define REG_GAMMA_CONTROL_3 0x32
+#define REG_GAMMA_CONTROL_4 0x33
+#define REG_GAMMA_CONTROL_5 0x34
+#define REG_GAMMA_CONTROL_6 0x35
+#define REG_GAMMA_CONTROL_7 0x36
+#define REG_GAMMA_CONTROL_8 0x37
+#define REG_GAMMA_CONTROL_9 0x38
+#define REG_GAMMA_CONTROL_10 0x39
+#define REG_GATE_SCAN_CONTROL 0x40
+#define REG_VERT_SCROLL_CONTROL 0x41
+#define REG_FIRST_SCREEN_DRIVE_POS 0x42
+#define REG_SECOND_SCREEN_DRIVE_POS 0x43
+#define REG_RAM_ADDR_POS_H 0x44
+#define REG_RAM_ADDR_POS_V 0x45
+#define REG_OSCILLATOR_CONTROL 0x4F
+#define REG_GPIO 0x60
+#define REG_OTP_VCM_PROGRAMMING 0x61
+#define REG_OTP_VCM_STATUS_ENABLE 0x62
+#define REG_OTP_PROGRAMMING_ID_KEY 0x65
+
+/*
+ * maximum frequency for register access
+ * (not for the GRAM access)
+ */
+#define ILITEK_MAX_FREQ_REG 4000000
+
+/*
+ * Device ID as found in the datasheet (supports 9221 and 9222)
+ */
+#define ILITEK_DEVICE_ID 0x9220
+#define ILITEK_DEVICE_ID_MASK 0xFFF0
+
+/* Last two bits in the START BYTE */
+#define START_RS_INDEX 0
+#define START_RS_REG 1
+#define START_RW_WRITE 0
+#define START_RW_READ 1
+
+/**
+ * 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) \
+ (0x70 | (((id) & 0x01) << 2) | (((rs) & 0x01) << 1) | ((rw) & 0x01))
+
+/**
+ * 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.
+ */
+#define CHECK_FREQ_REG(s, x) \
+ do { \
+ if (s->max_speed_hz > ILITEK_MAX_FREQ_REG) \
+ ((struct spi_transfer *)x)->speed_hz = \
+ ILITEK_MAX_FREQ_REG; \
+ } while (0)
+
+#define CMD_BUFSIZE 16
+
+#define POWER_IS_ON(pwr) ((pwr) <= FB_BLANK_NORMAL)
+
+#define set_tx_byte(b) (tx_invert ? ~(b) : b)
+
+/**
+ * ili922x_id - id as set by manufacturer
+ */
+static int ili922x_id = 1;
+module_param(ili922x_id, int, 0);
+
+static int tx_invert;
+module_param(tx_invert, int, 0);
+
+/**
+ * driver's private structure
+ */
+struct ili922x {
+ struct spi_device *spi;
+ struct lcd_device *ld;
+ int power;
+};
+
+/**
+ * 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)
+{
+ struct spi_message msg;
+ struct spi_transfer xfer;
+ unsigned char tbuf[CMD_BUFSIZE];
+ unsigned char rbuf[CMD_BUFSIZE];
+ int ret, i;
+
+ memset(&xfer, 0, sizeof(struct spi_transfer));
+ spi_message_init(&msg);
+ xfer.tx_buf = tbuf;
+ xfer.rx_buf = rbuf;
+ xfer.cs_change = 1;
+ CHECK_FREQ_REG(spi, &xfer);
+
+ tbuf[0] = set_tx_byte(START_BYTE(ili922x_id, START_RS_INDEX,
+ START_RW_READ));
+ /*
+ * we need 4-byte xfer here due to invalid dummy byte
+ * received after start byte
+ */
+ for (i = 1; i < 4; i++)
+ tbuf[i] = set_tx_byte(0); /* dummy */
+
+ xfer.bits_per_word = 8;
+ xfer.len = 4;
+ spi_message_add_tail(&xfer, &msg);
+ ret = spi_sync(spi, &msg);
+ if (ret < 0) {
+ dev_dbg(&spi->dev, "Error sending SPI message 0x%x", ret);
+ return ret;
+ }
+
+ *rs = (rbuf[2] << 8) + rbuf[3];
+ return 0;
+}
+
+/**
+ * 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)
+{
+ struct spi_message msg;
+ struct spi_transfer xfer_regindex, xfer_regvalue;
+ unsigned char tbuf[CMD_BUFSIZE];
+ unsigned char rbuf[CMD_BUFSIZE];
+ int ret, len = 0, send_bytes;
+
+ memset(&xfer_regindex, 0, sizeof(struct spi_transfer));
+ memset(&xfer_regvalue, 0, sizeof(struct spi_transfer));
+ spi_message_init(&msg);
+ xfer_regindex.tx_buf = tbuf;
+ xfer_regindex.rx_buf = rbuf;
+ xfer_regindex.cs_change = 1;
+ CHECK_FREQ_REG(spi, &xfer_regindex);
+
+ tbuf[0] = set_tx_byte(START_BYTE(ili922x_id, START_RS_INDEX,
+ START_RW_WRITE));
+ tbuf[1] = set_tx_byte(0);
+ tbuf[2] = set_tx_byte(reg);
+ xfer_regindex.bits_per_word = 8;
+ len = xfer_regindex.len = 3;
+ spi_message_add_tail(&xfer_regindex, &msg);
+
+ send_bytes = len;
+
+ tbuf[len++] = set_tx_byte(START_BYTE(ili922x_id, START_RS_REG,
+ START_RW_READ));
+ tbuf[len++] = set_tx_byte(0);
+ tbuf[len] = set_tx_byte(0);
+
+ xfer_regvalue.cs_change = 1;
+ xfer_regvalue.len = 3;
+ xfer_regvalue.tx_buf = &tbuf[send_bytes];
+ xfer_regvalue.rx_buf = &rbuf[send_bytes];
+ CHECK_FREQ_REG(spi, &xfer_regvalue);
+
+ spi_message_add_tail(&xfer_regvalue, &msg);
+ ret = spi_sync(spi, &msg);
+ if (ret < 0) {
+ dev_dbg(&spi->dev, "Error sending SPI message 0x%x", ret);
+ return ret;
+ }
+
+ *rx = (rbuf[1 + send_bytes] << 8) + rbuf[2 + send_bytes];
+ return 0;
+}
+
+/**
+ * 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)
+{
+ struct spi_message msg;
+ struct spi_transfer xfer_regindex, xfer_regvalue;
+ unsigned char tbuf[CMD_BUFSIZE];
+ unsigned char rbuf[CMD_BUFSIZE];
+ int ret, len = 0;
+
+ memset(&xfer_regindex, 0, sizeof(struct spi_transfer));
+ memset(&xfer_regvalue, 0, sizeof(struct spi_transfer));
+
+ spi_message_init(&msg);
+ xfer_regindex.tx_buf = tbuf;
+ xfer_regindex.rx_buf = rbuf;
+ xfer_regindex.cs_change = 1;
+ CHECK_FREQ_REG(spi, &xfer_regindex);
+
+ tbuf[0] = set_tx_byte(START_BYTE(ili922x_id, START_RS_INDEX,
+ START_RW_WRITE));
+ tbuf[1] = set_tx_byte(0);
+ tbuf[2] = set_tx_byte(reg);
+ xfer_regindex.bits_per_word = 8;
+ xfer_regindex.len = 3;
+ spi_message_add_tail(&xfer_regindex, &msg);
+
+ ret = spi_sync(spi, &msg);
+
+ spi_message_init(&msg);
+ len = 0;
+ tbuf[0] = set_tx_byte(START_BYTE(ili922x_id, START_RS_REG,
+ START_RW_WRITE));
+ tbuf[1] = set_tx_byte((value & 0xFF00) >> 8);
+ tbuf[2] = set_tx_byte(value & 0x00FF);
+
+ xfer_regvalue.cs_change = 1;
+ xfer_regvalue.len = 3;
+ xfer_regvalue.tx_buf = tbuf;
+ xfer_regvalue.rx_buf = rbuf;
+ CHECK_FREQ_REG(spi, &xfer_regvalue);
+
+ spi_message_add_tail(&xfer_regvalue, &msg);
+
+ ret = spi_sync(spi, &msg);
+ if (ret < 0) {
+ dev_err(&spi->dev, "Error sending SPI message 0x%x", ret);
+ return ret;
+ }
+ return 0;
+}
+
+#ifdef DEBUG
+/**
+ * ili922x_reg_dump - dump all registers
+ */
+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)
+{
+ struct spi_message msg;
+ struct spi_transfer xfer;
+ unsigned char tbuf[CMD_BUFSIZE];
+
+ memset(&xfer, 0, sizeof(struct spi_transfer));
+
+ spi_message_init(&msg);
+ xfer.tx_buf = tbuf;
+ xfer.rx_buf = NULL;
+ xfer.cs_change = 1;
+
+ tbuf[0] = START_BYTE(ili922x_id, START_RS_INDEX, START_RW_WRITE);
+ tbuf[1] = 0;
+ tbuf[2] = REG_WRITE_DATA_TO_GRAM;
+
+ xfer.bits_per_word = 8;
+ xfer.len = 3;
+ spi_message_add_tail(&xfer, &msg);
+ spi_sync(spi, &msg);
+}
+
+/**
+ * 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)
+{
+ int ret;
+
+ /* Power on */
+ ret = ili922x_write(spi, REG_POWER_CONTROL_1, 0x0000);
+ usleep_range(10000, 10500);
+ ret += ili922x_write(spi, REG_POWER_CONTROL_2, 0x0000);
+ ret += ili922x_write(spi, REG_POWER_CONTROL_3, 0x0000);
+ msleep(40);
+ ret += ili922x_write(spi, REG_POWER_CONTROL_4, 0x0000);
+ msleep(40);
+ /* register 0x56 is not documented in the datasheet */
+ ret += ili922x_write(spi, 0x56, 0x080F);
+ ret += ili922x_write(spi, REG_POWER_CONTROL_1, 0x4240);
+ usleep_range(10000, 10500);
+ ret += ili922x_write(spi, REG_POWER_CONTROL_2, 0x0000);
+ ret += ili922x_write(spi, REG_POWER_CONTROL_3, 0x0014);
+ msleep(40);
+ ret += ili922x_write(spi, REG_POWER_CONTROL_4, 0x1319);
+ msleep(40);
+
+ return ret;
+}
+
+/**
+ * ili922x_poweroff - turn the display off
+ * @spi: spi device
+ */
+static int ili922x_poweroff(struct spi_device *spi)
+{
+ int ret;
+
+ /* Power off */
+ ret = ili922x_write(spi, REG_POWER_CONTROL_1, 0x0000);
+ usleep_range(10000, 10500);
+ ret += ili922x_write(spi, REG_POWER_CONTROL_2, 0x0000);
+ ret += ili922x_write(spi, REG_POWER_CONTROL_3, 0x0000);
+ msleep(40);
+ ret += ili922x_write(spi, REG_POWER_CONTROL_4, 0x0000);
+ msleep(40);
+
+ return ret;
+}
+
+/**
+ * ili922x_display_init - initialize the display by setting
+ * the configuration registers
+ * @spi: spi device
+ */
+static void ili922x_display_init(struct spi_device *spi)
+{
+ ili922x_write(spi, REG_START_OSCILLATION, 1);
+ usleep_range(10000, 10500);
+ ili922x_write(spi, REG_DRIVER_OUTPUT_CONTROL, 0x691B);
+ ili922x_write(spi, REG_LCD_AC_DRIVEING_CONTROL, 0x0700);
+ ili922x_write(spi, REG_ENTRY_MODE, 0x1030);
+ ili922x_write(spi, REG_COMPARE_1, 0x0000);
+ ili922x_write(spi, REG_COMPARE_2, 0x0000);
+ ili922x_write(spi, REG_DISPLAY_CONTROL_1, 0x0037);
+ ili922x_write(spi, REG_DISPLAY_CONTROL_2, 0x0202);
+ ili922x_write(spi, REG_DISPLAY_CONTROL_3, 0x0000);
+ ili922x_write(spi, REG_FRAME_CYCLE_CONTROL, 0x0000);
+
+ /* Set RGB interface */
+ ili922x_write(spi, REG_EXT_INTF_CONTROL, 0x0110);
+
+ ili922x_poweron(spi);
+
+ ili922x_write(spi, REG_GAMMA_CONTROL_1, 0x0302);
+ ili922x_write(spi, REG_GAMMA_CONTROL_2, 0x0407);
+ ili922x_write(spi, REG_GAMMA_CONTROL_3, 0x0304);
+ ili922x_write(spi, REG_GAMMA_CONTROL_4, 0x0203);
+ ili922x_write(spi, REG_GAMMA_CONTROL_5, 0x0706);
+ ili922x_write(spi, REG_GAMMA_CONTROL_6, 0x0407);
+ ili922x_write(spi, REG_GAMMA_CONTROL_7, 0x0706);
+ ili922x_write(spi, REG_GAMMA_CONTROL_8, 0x0000);
+ ili922x_write(spi, REG_GAMMA_CONTROL_9, 0x0C06);
+ ili922x_write(spi, REG_GAMMA_CONTROL_10, 0x0F00);
+ ili922x_write(spi, REG_RAM_ADDRESS_SET, 0x0000);
+ ili922x_write(spi, REG_GATE_SCAN_CONTROL, 0x0000);
+ ili922x_write(spi, REG_VERT_SCROLL_CONTROL, 0x0000);
+ ili922x_write(spi, REG_FIRST_SCREEN_DRIVE_POS, 0xDB00);
+ ili922x_write(spi, REG_SECOND_SCREEN_DRIVE_POS, 0xDB00);
+ ili922x_write(spi, REG_RAM_ADDR_POS_H, 0xAF00);
+ ili922x_write(spi, REG_RAM_ADDR_POS_V, 0xDB00);
+ ili922x_reg_dump(spi);
+ set_write_to_gram_reg(spi);
+}
+
+static int ili922x_lcd_power(struct ili922x *lcd, int power)
+{
+ int ret = 0;
+
+ if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
+ ret = ili922x_poweron(lcd->spi);
+ else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
+ ret = ili922x_poweroff(lcd->spi);
+
+ if (!ret)
+ lcd->power = power;
+
+ return ret;
+}
+
+static int ili922x_set_power(struct lcd_device *ld, int power)
+{
+ struct ili922x *ili = lcd_get_data(ld);
+
+ return ili922x_lcd_power(ili, power);
+}
+
+static int ili922x_get_power(struct lcd_device *ld)
+{
+ struct ili922x *ili = lcd_get_data(ld);
+
+ return ili->power;
+}
+
+static struct lcd_ops ili922x_ops = {
+ .get_power = ili922x_get_power,
+ .set_power = ili922x_set_power,
+};
+
+static int ili922x_probe(struct spi_device *spi)
+{
+ struct ili922x *ili;
+ struct lcd_device *lcd;
+ int ret;
+ u16 reg = 0;
+
+ ili = devm_kzalloc(&spi->dev, sizeof(*ili), GFP_KERNEL);
+ if (!ili) {
+ dev_err(&spi->dev, "cannot alloc priv data\n");
+ return -ENOMEM;
+ }
+
+ ili->spi = spi;
+ dev_set_drvdata(&spi->dev, ili);
+
+ /* check if the device is connected */
+ ret = ili922x_read(spi, REG_DRIVER_CODE_READ, ®);
+ if (ret || ((reg & ILITEK_DEVICE_ID_MASK) != ILITEK_DEVICE_ID)) {
+ dev_err(&spi->dev,
+ "no LCD found: Chip ID 0x%x, ret %d\n",
+ reg, ret);
+ return -ENODEV;
+ } else {
+ dev_info(&spi->dev, "ILI%x found, SPI freq %d, mode %d\n",
+ reg, spi->max_speed_hz, spi->mode);
+ }
+
+ ret = ili922x_read_status(spi, ®);
+ if (ret) {
+ dev_err(&spi->dev, "reading RS failed...\n");
+ return ret;
+ } else
+ dev_dbg(&spi->dev, "status: 0x%x\n", reg);
+
+ ili922x_display_init(spi);
+
+ ili->power = FB_BLANK_POWERDOWN;
+
+ lcd = lcd_device_register("ili922xlcd", &spi->dev, ili,
+ &ili922x_ops);
+ if (IS_ERR(lcd)) {
+ dev_err(&spi->dev, "cannot register LCD\n");
+ return PTR_ERR(lcd);
+ }
+
+ ili->ld = lcd;
+ spi_set_drvdata(spi, ili);
+
+ ili922x_lcd_power(ili, FB_BLANK_UNBLANK);
+
+ return 0;
+}
+
+static int ili922x_remove(struct spi_device *spi)
+{
+ struct ili922x *ili = spi_get_drvdata(spi);
+
+ ili922x_poweroff(spi);
+ lcd_device_unregister(ili->ld);
+ return 0;
+}
+
+static struct spi_driver ili922x_driver = {
+ .driver = {
+ .name = "ili922x",
+ .owner = THIS_MODULE,
+ },
+ .probe = ili922x_probe,
+ .remove = ili922x_remove,
+};
+
+module_spi_driver(ili922x_driver);
+
+MODULE_AUTHOR("Stefano Babic <sbabic@denx.de>");
+MODULE_DESCRIPTION("ILI9221/9222 LCD driver");
+MODULE_LICENSE("GPL");
+MODULE_PARM_DESC(ili922x_id, "set controller identifier (default=1)");
+MODULE_PARM_DESC(tx_invert, "invert bytes before sending");
projects / mirror_ubuntu-artful-kernel.git / commitdiff