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>

4 files changed, 244 insertions, 13 deletions

diff --git a/board/fusb307bgevb/board.c b/board/fusb307bgevb/board.c
index 71b2c445da..9d92b5a560 100644
--- a/board/fusb307bgevb/board.c
+++ b/board/fusb307bgevb/board.c
@@ -8,27 +8,18 @@
 #include "ec_version.h"
 #include "gpio.h"
 #include "hooks.h"
+#include "i2c.h"
+#include "lcd.h"
 #include "queue_policies.h"
 #include "registers.h"
 #include "task.h"
+#include "timer.h"
 #include "usart-stm32f0.h"
 #include "usart_tx_dma.h"
 #include "usart_rx_dma.h"
 #include "usb_gpio.h"
 #include "usb-stream.h"
 #include "util.h"
-#include "usb_mux.h"
-#include "usb_charge.h"
-#include "usb_common.h"
-#include "usb_pd_tcpm.h"
-#include "usb_pd.h"
-#include "charge_state.h"
-#include "tcpm.h"
-#include "i2c.h"
-#include "power.h"
-#include "power_button.h"
-#include "printf.h"
-#include "timer.h"
 
 #define CPRINTS(format, args...) cprints(CC_USBCHARGE, format, ## args)
 #define CPRINTF(format, args...) cprintf(CC_USBCHARGE, format, ## args)
@@ -171,6 +162,11 @@ static void board_init(void)
 	/* Enable TCPC alert interrupts */
 	gpio_enable_interrupt(GPIO_USB_C0_PD_INT_ODL);
 
+	lcd_init(20, 4, 0);
+	lcd_set_cursor(0, 0);
+	lcd_print_string("USB-C");
+	lcd_set_cursor(0, 1);
+	lcd_print_string("Sink Advertiser");
 	queue_init(&loopback_queue);
 	queue_init(&usart_to_usb);
 	queue_init(&usb_to_usart);
diff --git a/board/fusb307bgevb/build.mk b/board/fusb307bgevb/build.mk
index ce45995412..1372562107 100644
--- a/board/fusb307bgevb/build.mk
+++ b/board/fusb307bgevb/build.mk
@@ -10,4 +10,4 @@ CHIP:=stm32
 CHIP_FAMILY:=stm32f0
 CHIP_VARIANT:=stm32f07x
 
-board-y=board.o
+board-y=board.o lcd.o
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);
+}
diff --git a/board/fusb307bgevb/lcd.h b/board/fusb307bgevb/lcd.h
new file mode 100644
index 0000000000..21b0ee9ce9
--- /dev/null
+++ b/board/fusb307bgevb/lcd.h
@@ -0,0 +1,69 @@
+/* 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.
+ */
+
+#ifndef __CROS_EC_LCD_H
+#define __CROS_EC_LCD_H
+
+#include "common.h"
+
+/* commands */
+#define LCD_CLEAR_DISPLAY	BIT(0)
+#define LCD_RETURN_HOME		BIT(1)
+#define LCD_ENTRYMODE_SET	BIT(2)
+#define LCD_DISPLAY_CONTROL	BIT(3)
+#define LCD_CURSOR_SHIFT	BIT(4)
+#define LCD_FUNCTION_SET	BIT(5)
+#define LCD_SET_CGRAMADDR	BIT(6)
+#define LCD_SET_DDRAMADDR	BIT(7)
+
+/* flags for display entry mode */
+#define LCD_ENTRY_RIGHT			0x00
+#define LCD_ENTRY_LEFT			BIT(1)
+#define LCD_ENTRY_SHIFT_INCREMENT	BIT(0)
+#define LCD_ENTRY_SHIFT_DECREMENT	0x00
+
+/* flags for display on/off control */
+#define LCD_DISPLAY_ON	BIT(2)
+#define LCD_DISPLAY_OFF	0x00
+#define LCD_CURSOR_ON	BIT(1)
+#define LCD_CURSOR_OFF	0x00
+#define LCD_BLINK_ON	BIT(0)
+#define LCD_BLINK_OFF	0x00
+
+/* flags for display/cursor shift */
+#define LCD_DISPLAY_MOVE	BIT(3)
+#define LCD_CURSOR_MOVE		0x00
+#define LCD_MOVE_RIGHT		BIT(2)
+#define LCD_MOVE_LEFT		0x00
+
+/* flags for function set */
+#define LCD_8BITMODE	BIT(4)
+#define LCD_4BITMODE	0x00
+#define LCD_2LINE	BIT(3)
+#define LCD_1LINE	0x00
+#define LCD_5X10DOTS	BIT(2)
+#define LCD_5X8DOTS	0x00
+
+/* flags for backlight control */
+#define LCD_BACKLIGHT		BIT(3)
+#define LCD_NO_BACKLIGHT	0x00
+
+#define LCD_EN	BIT(2) /* Enable bit */
+#define LCD_RW	BIT(1) /* Read/Write bit */
+#define LCD_RS	BIT(0) /* Register select bit */
+
+void lcd_init(uint8_t cols, uint8_t rows, uint8_t dotsize);
+void lcd_set_cursor(uint8_t col, uint8_t row);
+void lcd_set_char(char data);
+void lcd_print_string(const char *str);
+void lcd_clear(void);
+void lcd_enable_display(void);
+void lcd_disable_display(void);
+void lcd_enable_backlight(void);
+void lcd_disable_backlight(void);
+
+#endif /*__CROS_EC_LCD_H */