ucsa: add lcd driver

LCD 2004A driver, show "USB-C Sink Advertiser" on screen.

BUG=none
TEST=make buildall
BRANCH=master

Signed-off-by: Yun-Chieh Lee <lyunjie@google.com>
Change-Id: I4dc3932fba0077bc215f2e6c7855ba26995370ac
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2402852
Reviewed-by: Ting Shen <phoenixshen@chromium.org>

1 files changed, 166 insertions, 0 deletions

diff --git a/board/fusb307bgevb/lcd.c b/board/fusb307bgevb/lcd.c
new file mode 100644
index 0000000000..892888329e
--- /dev/null
+++ b/board/fusb307bgevb/lcd.c
@@ -0,0 +1,166 @@
+/* Copyright 2020 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * LCD driver for I2C LCD 2004.
+ */
+
+#include "i2c.h"
+#include "lcd.h"
+#include "timer.h"
+
+struct lcd_state_info {
+	uint8_t addr;
+	uint8_t displayfunction;
+	uint8_t displaycontrol;
+	uint8_t backlightval;
+};
+
+static struct lcd_state_info state = {
+	.addr = LCD_SLAVE_ADDR,
+	.backlightval = LCD_BACKLIGHT,
+	.displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5X8DOTS,
+};
+
+/************ low level data pushing commands **********/
+/* write either command or data */
+static void expander_write(uint8_t data)
+{
+	i2c_write8(I2C_PORT_TCPC, LCD_SLAVE_ADDR, 0x00, data |
+		state.backlightval);
+}
+
+static void pulse_enable(uint8_t data)
+{
+	expander_write(data | LCD_EN);/* En high */
+	usleep(1);	/* enable pulse must be >450ns */
+
+	expander_write(data & ~LCD_EN);/* En low */
+	usleep(50);	/* commands need > 37us to settle */
+}
+
+static void write_4bits(uint8_t value)
+{
+	expander_write(value);
+	pulse_enable(value);
+}
+
+static void send(uint8_t value, uint8_t mode)
+{
+	uint8_t highnib = value & 0xf0;
+	uint8_t lownib = (value << 4) & 0xf0;
+
+	write_4bits(highnib | mode);
+	write_4bits(lownib | mode);
+}
+
+/*********** mid level commands, for sending data/cmds */
+static void command(uint8_t value)
+{
+	send(value, 0);
+}
+
+/********** high level commands, for the user! */
+void lcd_clear(void)
+{
+	command(LCD_CLEAR_DISPLAY);/* clear display, set cursor to zero */
+	usleep(2000);	/* this command takes a long time! */
+}
+
+void lcd_set_cursor(uint8_t col, uint8_t row)
+{
+	int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
+
+	command(LCD_SET_DDRAMADDR | (col + row_offsets[row]));
+}
+
+void lcd_print_char(char data)
+{
+	send(data, LCD_RS);
+}
+
+void lcd_print_string(const char *str)
+{
+	while (*str)
+		lcd_print_char(*str++);
+}
+
+/* Turn the display on/off (quickly) */
+void lcd_disable_display(void)
+{
+	state.displaycontrol &= ~LCD_DISPLAY_ON;
+	command(LCD_DISPLAY_CONTROL | state.displaycontrol);
+}
+void lcd_enable_display(void)
+{
+	state.displaycontrol |= LCD_DISPLAY_ON;
+	command(LCD_DISPLAY_CONTROL | state.displaycontrol);
+}
+
+/* Turn the (optional) backlight off/on */
+void lcd_disable_backlight(void)
+{
+	state.backlightval = LCD_NO_BACKLIGHT;
+	expander_write(0);
+}
+
+void lcd_enable_backlight(void)
+{
+	state.backlightval = LCD_BACKLIGHT;
+	expander_write(0);
+}
+
+void lcd_init(uint8_t cols, uint8_t rows, uint8_t dotsize)
+{
+	if (rows > 1)
+		state.displayfunction |= LCD_2LINE;
+
+	/* for some 1 line displays you can select a 10 pixel high font */
+	if ((dotsize != 0) && (rows == 1))
+		state.displayfunction |= LCD_5X10DOTS;
+
+	/* SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
+	 * according to datasheet, we need at least 40ms after power rises
+	 * above 2.7V before sending commands. Arduino can turn on way
+	 * before 4.5V so we'll wait 50
+	 */
+	usleep(50);
+
+	/* Now we pull both RS and R/W low to begin commands */
+	/* reset expanderand turn backlight off (Bit 8 =1) */
+	expander_write(state.backlightval);
+	usleep(1000);
+
+	/* put the LCD into 4 bit mode
+	 * this is according to the hitachi HD44780 datasheet
+	 * figure 24, pg 46
+	 * we start in 8bit mode, try to set 4 bit mode
+	 */
+	write_4bits(0x03 << 4);
+	usleep(4500); /* wait min 4.1ms */
+	/*second try */
+	write_4bits(0x03 << 4);
+	usleep(4500); /* wait min 4.1ms */
+	/* third go! */
+	write_4bits(0x03 << 4);
+	usleep(150);
+	/* finally, set to 4-bit interface */
+	write_4bits(0x02 << 4);
+
+	/* set # lines, font size, etc. */
+	command(LCD_FUNCTION_SET | state.displayfunction);
+
+	/* turn the display on with no cursor or blinking default */
+	state.displaycontrol = LCD_DISPLAY_ON | LCD_CURSOR_OFF | LCD_BLINK_OFF;
+	lcd_enable_display();
+
+	/* clear it off */
+	lcd_clear();
+
+	/* Initialize to default text direction (for roman languages)
+	 * and set the entry mode
+	 */
+	command(LCD_ENTRYMODE_SET | LCD_ENTRY_LEFT | LCD_ENTRY_SHIFT_DECREMENT);
+
+	lcd_set_cursor(0, 0);
+}