nissa: deduplicate common board_config code

The sub-board configuration had diverged between Nivviks and Nereid,
with each having some disjoint improvements. This change moves all of
the code out of board-specific board_config files and into a common
file consisting of the sum of the two boards, and the few functions that
differ between boards are moved to existing board-specific source files.

Specifically, the divergence was:
 * Nereid configured HDMI as needed
 * Nereid fixed incorrect USB-A configuration for the LTE board
 * Nivviks disabled the C1 charger task if the port was not present

BUG=b:226513609,b:214858346
TEST=HDMI board still behaves correctly on Nereid, and USB ports still
     work with the C+A board on both Nivviks and Nereid.
BRANCH=none

Signed-off-by: Peter Marheine <pmarheine@chromium.org>
Change-Id: Iec0fac5c4fc880193a871ad302ea6752e02d8c01
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3559690
Reviewed-by: Andrew McRae <amcrae@google.com>

1 files changed, 198 insertions, 0 deletions

diff --git a/zephyr/projects/nissa/src/sub_board.c b/zephyr/projects/nissa/src/sub_board.c
new file mode 100644
index 0000000000..0ef2e217b0
--- /dev/null
+++ b/zephyr/projects/nissa/src/sub_board.c
@@ -0,0 +1,198 @@
+/* Copyright 2022 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.
+ */
+
+/* Nissa sub-board hardware configuration */
+
+#include <ap_power/ap_power.h>
+#include <drivers/gpio.h>
+#include <init.h>
+#include <kernel.h>
+#include <sys/printk.h>
+
+#include "driver/tcpm/tcpci.h"
+#include "gpio/gpio_int.h"
+#include "hooks.h"
+#include "usb_pd.h"
+#include "task.h"
+
+#include "nissa_common.h"
+
+LOG_MODULE_DECLARE(nissa, CONFIG_NISSA_LOG_LEVEL);
+
+static void hdmi_power_handler(struct ap_power_ev_callback *cb,
+			       struct ap_power_ev_data data)
+{
+	/* Enable rails for S3 */
+	const struct gpio_dt_spec *s3_rail =
+		GPIO_DT_FROM_ALIAS(gpio_hdmi_en_odl);
+	/* Enable rails for S5 */
+	const struct gpio_dt_spec *s5_rail =
+		GPIO_DT_FROM_ALIAS(gpio_en_rails_odl);
+	/* Connect DDC to sub-board */
+	const struct gpio_dt_spec *ddc_select =
+		GPIO_DT_FROM_NODELABEL(gpio_hdmi_sel);
+
+	switch (data.event) {
+	case AP_POWER_PRE_INIT:
+		LOG_DBG("Enabling HDMI+USB-A PP5000 and selecting DDC");
+		gpio_pin_set_dt(s5_rail, 1);
+		gpio_pin_set_dt(ddc_select, 1);
+		break;
+	case AP_POWER_STARTUP:
+		LOG_DBG("Enabling HDMI VCC");
+		gpio_pin_set_dt(s3_rail, 1);
+		break;
+	case AP_POWER_SHUTDOWN:
+		LOG_DBG("Disabling HDMI VCC");
+		gpio_pin_set_dt(s3_rail, 0);
+		break;
+	case AP_POWER_HARD_OFF:
+		LOG_DBG("Disabling HDMI+USB-A PP5000 and deselecting DDC");
+		gpio_pin_set_dt(ddc_select, 0);
+		gpio_pin_set_dt(s5_rail, 0);
+		break;
+	default:
+		LOG_ERR("Unhandled HDMI power event %d", data.event);
+		break;
+	}
+}
+
+static void hdmi_hpd_interrupt(const struct device *device,
+			       struct gpio_callback *callback,
+			       gpio_port_pins_t pins)
+{
+	int state = gpio_pin_get_dt(GPIO_DT_FROM_ALIAS(gpio_hpd_odl));
+
+	gpio_pin_set_dt(GPIO_DT_FROM_NODELABEL(gpio_ec_soc_hdmi_hpd), state);
+	LOG_DBG("HDMI HPD changed state to %d", state);
+}
+
+/**
+ * Configure GPIOs (and other pin functions) that vary with present sub-board.
+ *
+ * The functions of some pins vary according to which sub-board is present
+ * (indicated by CBI fw_config); this function configures them according to the
+ * needs of the present sub-board.
+ */
+static int nissa_subboard_config(const struct device *unused)
+{
+	ARG_UNUSED(unused);
+	enum nissa_sub_board_type sb = nissa_get_sb_type();
+
+	/*
+	 * USB-A port: current limit output is configured by default and unused
+	 * if this port is not present. VBUS enable must be configured if
+	 * needed and is controlled by the usba-port-enable-pins driver.
+	 */
+	if (sb == NISSA_SB_C_A || sb == NISSA_SB_HDMI_A) {
+		/* Configure VBUS enable, default off */
+		gpio_pin_configure_dt(
+			GPIO_DT_FROM_ALIAS(gpio_en_usb_a1_vbus),
+			GPIO_OUTPUT_LOW);
+	} else {
+		/* Turn off unused pins */
+		gpio_pin_configure_dt(
+			GPIO_DT_FROM_NODELABEL(gpio_sub_usb_a1_ilimit_sdp),
+			GPIO_DISCONNECTED);
+		gpio_pin_configure_dt(
+			GPIO_DT_FROM_ALIAS(gpio_en_usb_a1_vbus),
+			GPIO_DISCONNECTED);
+	}
+	/*
+	 * USB-C port: the default configuration has I2C on the I2C pins,
+	 * but the interrupt line needs to be configured and USB mux
+	 * configuration provided.
+	 */
+	if (sb == NISSA_SB_C_A || sb == NISSA_SB_C_LTE) {
+		/* Configure interrupt input */
+		gpio_pin_configure_dt(
+			GPIO_DT_FROM_ALIAS(gpio_usb_c1_int_odl),
+			GPIO_INPUT | GPIO_PULL_UP);
+		usb_muxes[1].next_mux = nissa_get_c1_sb_mux();
+	} else {
+		/* Disable the port 1 charger task */
+		task_disable_task(TASK_ID_USB_CHG_P1);
+	}
+	/*
+	 * HDMI: two outputs control power which must be configured to
+	 * non-default settings, and HPD must be forwarded to the AP on
+	 * another output pin.
+	 */
+	if (sb == NISSA_SB_HDMI_A) {
+		const struct gpio_dt_spec *hpd_gpio =
+			GPIO_DT_FROM_ALIAS(gpio_hpd_odl);
+		static struct ap_power_ev_callback hdmi_power_cb;
+		static struct gpio_callback hdmi_hpd_cb;
+		int rv, irq_key;
+
+		/* HDMI power enable outputs */
+		gpio_pin_configure_dt(GPIO_DT_FROM_ALIAS(gpio_en_rails_odl),
+				      GPIO_OUTPUT_INACTIVE | GPIO_OPEN_DRAIN |
+					      GPIO_PULL_UP | GPIO_ACTIVE_LOW);
+		gpio_pin_configure_dt(GPIO_DT_FROM_ALIAS(gpio_hdmi_en_odl),
+				      GPIO_OUTPUT_INACTIVE | GPIO_OPEN_DRAIN |
+					      GPIO_ACTIVE_LOW);
+		/* Control HDMI power in concert with AP */
+		ap_power_ev_init_callback(
+			&hdmi_power_cb, hdmi_power_handler,
+			AP_POWER_PRE_INIT | AP_POWER_HARD_OFF |
+				AP_POWER_STARTUP | AP_POWER_SHUTDOWN);
+		ap_power_ev_add_callback(&hdmi_power_cb);
+
+		/*
+		 * Configure HPD input from sub-board; it's inverted by a buffer
+		 * on the sub-board.
+		 */
+		gpio_pin_configure_dt(hpd_gpio, GPIO_INPUT | GPIO_ACTIVE_LOW);
+		/* Register interrupt handler for HPD changes */
+		gpio_init_callback(&hdmi_hpd_cb, hdmi_hpd_interrupt,
+				   BIT(hpd_gpio->pin));
+		gpio_add_callback(hpd_gpio->port, &hdmi_hpd_cb);
+		rv = gpio_pin_interrupt_configure_dt(hpd_gpio,
+						     GPIO_INT_EDGE_BOTH);
+		__ASSERT(rv == 0,
+			 "HPD interrupt configuration returned error %d", rv);
+		/*
+		 * Run the HPD handler once to ensure output is in sync.
+		 * Lock interrupts to ensure that we don't cause desync if an
+		 * HPD interrupt comes in between the internal read of the input
+		 * and write to the output.
+		 */
+		irq_key = irq_lock();
+		hdmi_hpd_interrupt(hpd_gpio->port, &hdmi_hpd_cb,
+				   BIT(hpd_gpio->pin));
+		irq_unlock(irq_key);
+	}
+
+	return 0;
+}
+SYS_INIT(nissa_subboard_config, APPLICATION, HOOK_PRIO_POST_FIRST);
+
+/*
+ * Enable interrupts
+ */
+static int board_init(const struct device *unused)
+{
+	ARG_UNUSED(unused);
+	/*
+	 * Enable USB-C interrupts.
+	 */
+	gpio_enable_dt_interrupt(GPIO_INT_FROM_NODELABEL(int_usb_c0));
+	if (board_get_usb_pd_port_count() == 2)
+		gpio_enable_dt_interrupt(GPIO_INT_FROM_NODELABEL(int_usb_c1));
+
+	return 0;
+}
+SYS_INIT(board_init, APPLICATION, HOOK_PRIO_DEFAULT);
+
+/* Trigger shutdown by enabling the Z-sleep circuit */
+__override void board_hibernate_late(void)
+{
+	gpio_pin_set_dt(GPIO_DT_FROM_NODELABEL(gpio_en_slp_z), 1);
+	/*
+	 * The system should hibernate, but there may be
+	 * a small delay, so return.
+	 */
+}