honeybuns: Add power button support

This CL adds support for the power button including a new task to
allow for power sequencing delays.

The power button is used for two purposes. First, to turn the dock on
or off, and second, to allow for a user set preference of the MF for
DP 2 or 4 lane selection. If the dock is off, the dock will be turned
on as soon as the short press timer expires. If the dock is already
on, then a short press action is only recognized on the release so a
long press will only change the MF preference.

BUG=b:164157329
BRANCH=quiche
TEST=manaual
short press -> turns dock on off as expected
long press -> toggles MF preference and flashes LED

Signed-off-by: Scott Collyer <scollyer@google.com>
Change-Id: I8519c072a7f10657c369344ead6149fc7d31bb36
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2718268
Tested-by: Scott Collyer <scollyer@chromium.org>
Reviewed-by: Sam Hurst <shurst@google.com>
Commit-Queue: Scott Collyer <scollyer@chromium.org>

2 files changed, 364 insertions, 17 deletions

diff --git a/baseboard/honeybuns/baseboard.c b/baseboard/honeybuns/baseboard.c
index 3b6d4ba626..3425417b81 100644
--- a/baseboard/honeybuns/baseboard.c
+++ b/baseboard/honeybuns/baseboard.c
@@ -11,24 +11,81 @@
 #include "i2c.h"
 #include "usb_pd.h"
 #include "system.h"
+#include "task.h"
 #include "timer.h"
+#include "usbc_ppc.h"
+#include "driver/tcpm/tcpm.h"
 #include "util.h"
 
 #define CPRINTS(format, args...) cprints(CC_SYSTEM, format, ## args)
 #define CPRINTF(format, args...) cprintf(CC_SYSTEM, format, ## args)
 
+#define POWER_BUTTON_SHORT_USEC (300 * MSEC)
+#define POWER_BUTTON_LONG_USEC (5000 * MSEC)
+#define POWER_BUTTON_DEBOUNCE_USEC (30)
+
+#define BUTTON_PRESSED_LEVEL 1
+#define BUTTON_RELEASED_LEVEL 0
+
+#define BUTTON_EVT_CHANGE   BIT(0)
+#define BUTTON_EVT_INFO     BIT(1)
+
+enum power {
+	POWER_OFF,
+	POWER_ON
+};
+
+enum button {
+	BUTTON_RELEASE,
+	BUTTON_PRESS,
+	BUTTON_PRESS_POWER_ON,
+	BUTTON_PRESS_SHORT,
+	BUTTON_PRESS_LONG,
+};
+
+#define LED_ON_OFF_BIT BIT(0)
+#define LED_COLOR_BIT BIT(2)
+#define LED_FLASH_SEQ_LENGTH 8
+
+enum led_color {
+	GREEN,
+	YELLOW,
+	OFF,
+};
+
+static enum power dock_state;
+#ifdef SECTION_IS_RW
+static int button_level;
+static int button_level_pending;
+static int dock_mf;
+static int led_count;
+#endif
+
 /******************************************************************************/
 
-static void board_power_sequence(void)
+__maybe_unused static void board_power_sequence(int enable)
 {
 	int i;
 
-	for(i = 0; i < board_power_seq_count; i++) {
-		gpio_set_level(board_power_seq[i].signal,
-			       board_power_seq[i].level);
-		if (board_power_seq[i].delay_ms)
-			msleep(board_power_seq[i].delay_ms);
+	if (enable) {
+		for(i = 0; i < board_power_seq_count; i++) {
+			gpio_set_level(board_power_seq[i].signal,
+				       board_power_seq[i].level);
+			CPRINTS("power seq: rail = %d", i);
+			if (board_power_seq[i].delay_ms)
+				msleep(board_power_seq[i].delay_ms);
+		}
+	} else {
+		for(i = board_power_seq_count - 1; i >= 0; i--) {
+			gpio_set_level(board_power_seq[i].signal,
+				       !board_power_seq[i].level);
+			CPRINTS("sequence[%d]: level = %d", i,
+				!board_power_seq[i].level);
+		}
 	}
+
+	dock_state = enable;
+	CPRINTS("board: Power rails %s", dock_state ? "on" : "off");
 }
 
 /******************************************************************************/
@@ -39,31 +96,92 @@ const struct i2c_port_t i2c_ports[] = {
 };
 const unsigned int i2c_ports_used = ARRAY_SIZE(i2c_ports);
 
+#ifdef SECTION_IS_RW
+static void baseboard_set_led(enum led_color color)
+{
+	/*
+	 * TODO(b/164157329): The power button feature should be connected to a
+	 * 2 color LED which is part of the button. Currently, the power button
+	 * LED is a single color LED which is controlled by on the of the power
+	 * rails. Using the status LED now to demonstrate the LED behavior
+	 * associated with a power button press.
+	 */
+	CPRINTS("led: color = %d", color);
+	if (color == OFF) {
+		gpio_set_level(GPIO_EC_STATUS_LED1, 1);
+		gpio_set_level(GPIO_EC_STATUS_LED2, 1);
+	} else if (color == GREEN) {
+		gpio_set_level(GPIO_EC_STATUS_LED1, 1);
+		gpio_set_level(GPIO_EC_STATUS_LED2, 0);
+	} else if (color == YELLOW) {
+		gpio_set_level(GPIO_EC_STATUS_LED1, 0);
+		gpio_set_level(GPIO_EC_STATUS_LED2, 0);
+	}
+}
+
+static void baseboard_led_callback(void);
+DECLARE_DEFERRED(baseboard_led_callback);
 
-void baseboard_set_mst_lane_control(int dock_mf)
+static void baseboard_led_callback(void)
 {
-	/* Check if lane swich level is changing */
-	if (dock_mf != gpio_get_level(GPIO_MST_HUB_LANE_SWITCH)) {
+	/*
+	 * Flash LED on transition using a simple 3 bit counter. Bit 0 controls
+	 * LED on/off and bit 2 controls which color to set during the on phase.
+	 */
+	int color = led_count & LED_COLOR_BIT ? dock_mf : dock_mf ^ 1;
+
+	/*
+	 * TODO(b/164157329): This function implements a simple flashing
+	 * transition when the MF preference bit is changed via a long power
+	 * button press sequence. This might need to move to the board function
+	 * if not required/desired on all variants.
+	 */
+
+	if (led_count & LED_ON_OFF_BIT)
+		baseboard_set_led(color);
+	else
+		baseboard_set_led(OFF);
+
+	/* Flash sequence is 8 steps */
+	if (++led_count < LED_FLASH_SEQ_LENGTH)
+		hook_call_deferred(&baseboard_led_callback_data, 150 * MSEC);
+}
+
+static void baseboard_change_mf_led(void)
+{
+	led_count = 0;
+	baseboard_led_callback();
+}
+
+void baseboard_set_mst_lane_control(int mf)
+{
+	/*
+	 * The parameter mf reflects the desired lane control value. If the
+	 * current value does not match the desired, then the MST hub must first
+	 * be put into reset, so the MST hub will latch in the correct value
+	 * when it's taken out of reset.
+	 */
+	if (mf != gpio_get_level(GPIO_MST_HUB_LANE_SWITCH)) {
 		/* put MST into reset */
 		gpio_set_level(GPIO_MST_RST_L, 0);
 		msleep(1);
-		gpio_set_level(GPIO_MST_HUB_LANE_SWITCH, dock_mf);
-		CPRINTS("MST: lane control = %s", dock_mf ? "high" : "low");
+		gpio_set_level(GPIO_MST_HUB_LANE_SWITCH, mf);
+		CPRINTS("MST: lane control = %s", mf ? "high" : "low");
 		msleep(1);
 		/* lane control is set, take MST out of reset */
 		gpio_set_level(GPIO_MST_RST_L, 1);
 	}
 }
+#endif /* SECTION_IS_RW */
 
 static void baseboard_init(void)
 {
 #ifdef SECTION_IS_RW
-	int rv;
 	uint32_t fw_config;
 #endif
 
 	/* Turn on power rails */
-	board_power_sequence();
+	board_power_sequence(1);
 	CPRINTS("board: Power rails enabled");
 
 #ifdef SECTION_IS_RW
@@ -77,9 +195,16 @@ static void baseboard_init(void)
 	 * field of the CBI. If this value is programmed, then make sure the
 	 * MST_LANE_CONTROL gpio matches the mf bit.
 	 */
-	rv = cbi_get_fw_config(&fw_config);
-	if (!rv)
-		baseboard_set_mst_lane_control(fw_config & 1);
+	if (cbi_get_fw_config(&fw_config)) {
+		dock_mf = CBI_FW_MF_PREFERENCE(fw_config);
+		baseboard_set_mst_lane_control(dock_mf);
+	}
+
+	/* Enable power button interrupt */
+	gpio_enable_interrupt(GPIO_PWR_BTN);
+	/* Set dock mf preference LED */
+	baseboard_set_led(dock_mf);
+
 #else
 	/* Set up host port usbc to present Rd on CC lines */
 	if(baseboard_usbc_init(USB_PD_PORT_HOST))
@@ -91,3 +216,223 @@ static void baseboard_init(void)
  * power sequencing as soon as I2C bus is initialized.
  */
 DECLARE_HOOK(HOOK_INIT, baseboard_init, HOOK_PRIO_INIT_I2C + 1);
+
+#ifdef SECTION_IS_RW
+static void baseboard_power_on(void)
+{
+	int port_max = board_get_usb_pd_port_count();
+	int port;
+
+	/* Adjust system flags to full PPC init occurs */
+	system_clear_reset_flags(EC_RESET_FLAG_POWER_ON);
+	system_set_reset_flags(EC_RESET_FLAG_EFS);
+	/* Enable power rails and release reset signals */
+	board_power_sequence(1);
+	/*
+	 * Lane control (realtek MST) must be set prior to releasing MST
+	 * reset.
+	 */
+	baseboard_set_mst_lane_control(dock_mf);
+	/*
+	 * When the power to the PPC is turned off, then back on, the PPC will
+	 * default into dead battery mode. Dead battery resistors are disabled
+	 * as part of the full PPC intializaiton sequence. This is required to
+	 * force a detach event with port parter which can be attached as usbc
+	 * source when honeybuns power rails are off.
+	 */
+	for (port = 0; port < port_max; port++) {
+		ppc_init(port);
+		msleep(1000);
+		/* Inform TC state machine that it can resume */
+		pd_set_suspend(port, 0);
+	}
+	/* Enable usbc interrupts */
+	board_enable_usbc_interrupts();
+}
+
+static void baseboard_power_off(void)
+{
+	int port_max = board_get_usb_pd_port_count();
+	int port;
+
+	/* Put ports in TC suspend state */
+	for (port = 0; port < port_max; port++)
+		pd_set_suspend(port, 1);
+
+	/* Disable ucpd peripheral (prevents interrupts) */
+	tcpm_release(USB_PD_PORT_HOST);
+	/* Disable PPC/TCPC interrupts */
+	board_disable_usbc_interrupts();
+	/* Go into power off state */
+	board_power_sequence(0);
+}
+
+static void baseboard_toggle_mf(void)
+{
+	uint32_t fw_config;
+
+	if (!cbi_get_fw_config(&fw_config)) {
+		/* Update the user MF preference stored in CBI */
+		fw_config ^= CBI_FW_MF_MASK;
+		cbi_set_fw_config(fw_config);
+		/* Update variable used to track user MF preference */
+		dock_mf = CBI_FW_MF_PREFERENCE(fw_config);
+		/* Flash led for visual indication of user MF change */
+		baseboard_change_mf_led();
+		/* Power the dock off, then on, to apply user preference */
+		baseboard_power_off();
+		baseboard_power_on();
+	}
+}
+
+/*
+ * Main task entry point for UCPD task
+ */
+void power_button_task(void *u)
+{
+	int timer_us = POWER_BUTTON_DEBOUNCE_USEC * 4;
+	enum button state = BUTTON_RELEASE;
+	uint32_t evt;
+
+	/*
+	 * Capture current button level in case it's being pressed when the dock
+	 * is powered on. Note timer_us is initialized for debounce time to
+	 * double check.
+	 */
+	button_level = gpio_get_level(GPIO_PWR_BTN);
+
+	while (1) {
+		evt = task_wait_event(timer_us);
+		timer_us = -1;
+
+		if (evt == BUTTON_EVT_INFO) {
+			/* Only used for console command for debug */
+			CPRINTS("pwrbtn: pwr = %d, state = %d, level = %d",
+				dock_state, state, button_level);
+			continue;
+		}
+
+		switch (state) {
+		case BUTTON_RELEASE:
+			/*
+			 * Default wait state: Only need to check if the button
+			 * is pressed and start the short press timer.
+			 */
+			if (evt & BUTTON_EVT_CHANGE && button_level ==
+			    BUTTON_PRESSED_LEVEL) {
+				state = BUTTON_PRESS;
+				timer_us = (POWER_BUTTON_SHORT_USEC -
+						 POWER_BUTTON_DEBOUNCE_USEC);
+			}
+			break;
+		case BUTTON_PRESS:
+			/*
+			 * Validate short press by ensuring that button is still
+			 * pressed after short press timer expires.
+			 */
+			if (evt & BUTTON_EVT_CHANGE &&
+			    button_level == BUTTON_RELEASED_LEVEL) {
+				state = BUTTON_RELEASE;
+			} else {
+				/* Start long press timer */
+				timer_us = POWER_BUTTON_LONG_USEC -
+					POWER_BUTTON_SHORT_USEC;
+				/*
+				 * If dock is currently off, then change to the
+				 * power on state. If dock is already on, then
+				 * advance to short press state.
+				 */
+				if (dock_state == POWER_OFF) {
+					baseboard_power_on();
+				        state = BUTTON_PRESS_POWER_ON;
+				} else {
+					state = BUTTON_PRESS_SHORT;
+				}
+			}
+			break;
+		case BUTTON_PRESS_POWER_ON:
+			/*
+			 * Short press recognized and dock was just powered
+			 * on. If button is no longer pressed, then just return
+			 * to the default state. Else, button is still pressed
+			 * after long press timer has expired.
+			 */
+			if (evt & BUTTON_EVT_CHANGE &&
+			    button_level == BUTTON_RELEASED_LEVEL) {
+				state = BUTTON_RELEASE;
+			} else {
+				state = BUTTON_PRESS_LONG;
+				baseboard_toggle_mf();
+			}
+			break;
+		case BUTTON_PRESS_SHORT:
+			/*
+			 * Short press was recognized and dock power state was
+			 * already on. If button is now released, then turn dock
+			 * off.
+			 */
+			if (evt & BUTTON_EVT_CHANGE &&
+			    button_level == BUTTON_RELEASED_LEVEL) {
+				state = BUTTON_RELEASE;
+				baseboard_power_off();
+			} else {
+				state = BUTTON_PRESS_LONG;
+				baseboard_toggle_mf();
+			}
+			break;
+		case BUTTON_PRESS_LONG:
+			if (evt & BUTTON_EVT_CHANGE &&
+			    button_level == BUTTON_RELEASED_LEVEL) {
+				state = BUTTON_RELEASE;
+			}
+			break;
+		}
+	}
+}
+
+static void baseboard_power_button_debounce(void)
+{
+	int level = gpio_get_level(GPIO_PWR_BTN);
+
+	/* Sanity check, level should be same after debounce interval */
+	if (level != button_level_pending)
+		return;
+
+	button_level = level;
+	task_set_event(TASK_ID_POWER_BUTTON, BUTTON_EVT_CHANGE);
+}
+DECLARE_DEFERRED(baseboard_power_button_debounce);
+
+void baseboard_power_button_evt(int level)
+{
+	button_level_pending = level;
+
+	hook_call_deferred(&baseboard_power_button_debounce_data,
+			   POWER_BUTTON_DEBOUNCE_USEC);
+}
+
+static int command_pwr_btn(int argc, char **argv)
+{
+
+	if (argc == 1) {
+		task_set_event(TASK_ID_POWER_BUTTON, BUTTON_EVT_INFO);
+		return EC_SUCCESS;
+	}
+
+	if (!strcasecmp(argv[1], "on")) {
+		baseboard_power_on();
+	} else if (!strcasecmp(argv[1], "off")) {
+		baseboard_power_off();
+	} else if (!strcasecmp(argv[1], "mf")) {
+		baseboard_toggle_mf();
+	} else {
+		return EC_ERROR_PARAM1;
+	}
+
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(pwr_btn, command_pwr_btn,
+			"<on|off|mf>",
+			"Simulate Power Button Press");
+
+#endif
diff --git a/baseboard/honeybuns/baseboard.h b/baseboard/honeybuns/baseboard.h
index 0faf727ab8..76bcaf490d 100644
--- a/baseboard/honeybuns/baseboard.h
+++ b/baseboard/honeybuns/baseboard.h
@@ -87,7 +87,8 @@
 #define CONFIG_CROS_BOARD_INFO
 #define CONFIG_BOARD_VERSION_CBI
 #define CONFIG_CMD_CBI
-#define CONFIG_CMD_CBI_SET
+#define CBI_FW_MF_MASK BIT(0)
+#define CBI_FW_MF_PREFERENCE(val) (val & (CBI_FW_MF_MASK))
 
 /* USB Configuration */
 #define CONFIG_USB
@@ -228,6 +229,7 @@ enum adc_channel {
 
 extern const struct power_seq board_power_seq[];
 extern const size_t board_power_seq_count;
+void baseboard_power_button_evt(int level);
 
 /*
  * Configure the host port to present Rd on both CC lines. This function is