zephyr: subsys/ap_pwrseq: Add espi callback handling

Change of power signals over espi (SLP_S3/S4/S5) would
change the power sequence state machine.

BUG=b:203446068
BRANCH=None
TEST=zmake testall; verified prints to indicate SLP signal
changes during boot.

Change-Id: Icabcddfabf687470f5266a7d537343691877c198
Signed-off-by: Divya Sasidharan <divya.s.sasidharan@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3378975
Reviewed-by: Andrew McRae <amcrae@google.com>

6 files changed, 134 insertions, 0 deletions

diff --git a/zephyr/dts/bindings/power/intel,ap-pwrseq.yaml b/zephyr/dts/bindings/power/intel,ap-pwrseq.yaml
index f584c19df7..ebc875814d 100644
--- a/zephyr/dts/bindings/power/intel,ap-pwrseq.yaml
+++ b/zephyr/dts/bindings/power/intel,ap-pwrseq.yaml
@@ -79,6 +79,13 @@ properties:
       description: |
         Timeout in ms for monitoring power signals.
 
+    pwrseq-espi-max-freq:
+      type: int
+      required: false
+      default: 20
+      description: |
+        Maximum configured frequency for espi channel.
+
     pg-ec-dsw-pwrok-gpios:
       type: phandle-array
       required: false
diff --git a/zephyr/subsys/ap_pwrseq/CMakeLists.txt b/zephyr/subsys/ap_pwrseq/CMakeLists.txt
index f08bb3e476..e4f5c6c3d3 100644
--- a/zephyr/subsys/ap_pwrseq/CMakeLists.txt
+++ b/zephyr/subsys/ap_pwrseq/CMakeLists.txt
@@ -3,6 +3,7 @@
 zephyr_include_directories(include)
 zephyr_sources_ifdef(CONFIG_X86_NON_DSX_PWRSEQ
 	x86_non_dsx_common_pwrseq_sm_handler.c)
+zephyr_sources_ifdef(CONFIG_X86_NON_DSX_PWRSEQ   x86_non_dsx_espi.c)
 zephyr_sources_ifdef(CONFIG_X86_NON_DSX_PWRSEQ_CONSOLE
 	x86_non_dsx_common_pwrseq_console.c)
 zephyr_sources_ifdef(CONFIG_X86_NON_DSX_PWRSEQ_ADL   x86_non_dsx_adlp_pwrseq_sm.c)
diff --git a/zephyr/subsys/ap_pwrseq/include/x86_non_dsx_common_pwrseq_sm_handler.h b/zephyr/subsys/ap_pwrseq/include/x86_non_dsx_common_pwrseq_sm_handler.h
index fe1aae194f..51c1c17a6c 100644
--- a/zephyr/subsys/ap_pwrseq/include/x86_non_dsx_common_pwrseq_sm_handler.h
+++ b/zephyr/subsys/ap_pwrseq/include/x86_non_dsx_common_pwrseq_sm_handler.h
@@ -7,6 +7,8 @@
 #define __X86_NON_DSX_COMMON_PWRSEQ_SM_HANDLER_H__
 
 #include <x86_common_pwrseq.h>
+#include <x86_non_dsx_espi.h>
+#include <zephyr/types.h>
 
 #define DT_DRV_COMPAT intel_ap_pwrseq
 #define INTEL_COM_POWER_NODE	DT_INST(0, intel_ap_pwrseq)
diff --git a/zephyr/subsys/ap_pwrseq/include/x86_non_dsx_espi.h b/zephyr/subsys/ap_pwrseq/include/x86_non_dsx_espi.h
new file mode 100644
index 0000000000..72ee197d92
--- /dev/null
+++ b/zephyr/subsys/ap_pwrseq/include/x86_non_dsx_espi.h
@@ -0,0 +1,21 @@
+/* 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.
+ */
+
+#ifndef __X86_NON_DSX_ESPI_H__
+#define __X86_NON_DSX_ESPI_H__
+
+/**
+ * @brief Configure eSPI channels for Non Deep Sleep well platforms
+ */
+void ndsx_espi_configure(void);
+
+/**
+ * @brief Return Virtual wire value
+
+ * @retval Actual Virtual Wire value or 0 on failure
+ */
+uint8_t vw_get_level(enum espi_vwire_signal signal);
+
+#endif /* __NDSX_ESPI_H__ */
diff --git a/zephyr/subsys/ap_pwrseq/x86_non_dsx_common_pwrseq_sm_handler.c b/zephyr/subsys/ap_pwrseq/x86_non_dsx_common_pwrseq_sm_handler.c
index 8c23b4de8a..c87dbc111d 100644
--- a/zephyr/subsys/ap_pwrseq/x86_non_dsx_common_pwrseq_sm_handler.c
+++ b/zephyr/subsys/ap_pwrseq/x86_non_dsx_common_pwrseq_sm_handler.c
@@ -292,6 +292,8 @@ static int pwrseq_init()
 	/* Configure gpio from device tree */
 	pwrseq_gpio_init();
 	LOG_DBG("Done gpio init");
+	/* Register espi handler */
+	ndsx_espi_configure();
 	/* TODO: Define initial state of power sequence */
 	LOG_DBG("Init pwr seq state");
 	init_pwr_seq_state();
diff --git a/zephyr/subsys/ap_pwrseq/x86_non_dsx_espi.c b/zephyr/subsys/ap_pwrseq/x86_non_dsx_espi.c
new file mode 100644
index 0000000000..9625adca57
--- /dev/null
+++ b/zephyr/subsys/ap_pwrseq/x86_non_dsx_espi.c
@@ -0,0 +1,101 @@
+/* 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.
+ */
+
+#include <drivers/espi.h>
+#include <x86_non_dsx_espi.h>
+#include <x86_non_dsx_common_pwrseq_sm_handler.h>
+
+LOG_MODULE_DECLARE(ap_pwrseq, 3);
+
+#define espi_dev DEVICE_DT_GET(DT_CHOSEN(intel_ap_pwrseq_espi))
+
+struct espi_callback espi_bus_cb;
+struct espi_callback espi_chan_cb;
+struct espi_callback espi_vw_cb;
+
+static void espi_bus_vw_handler(const struct device *dev,
+				struct espi_callback *cb,
+				struct espi_event event)
+{
+	LOG_DBG("VW is triggered, event=%d, val=%d\n", event.evt_details,
+			vw_get_level(event.evt_details));
+
+	switch (event.evt_details) {
+	case ESPI_VWIRE_SIGNAL_SLP_S3:
+	case ESPI_VWIRE_SIGNAL_SLP_S4:
+		break;
+	default:
+		break;
+	}
+}
+
+/* This should be overridden by the chipset */
+__attribute__((weak)) void espi_bus_reset(void)
+{
+  /* Do nothing */
+}
+
+static void espi_bus_reset_handler(const struct device *dev,
+				struct espi_callback *cb,
+				struct espi_event event)
+{
+	LOG_DBG("ESPI bus reset");
+	espi_bus_reset();
+}
+
+static void espi_bus_channel_handler(const struct device *dev,
+				struct espi_callback *cb,
+				struct espi_event event)
+{
+	LOG_DBG("ESPI channel ready");
+}
+
+uint8_t vw_get_level(enum espi_vwire_signal signal)
+{
+	uint8_t level;
+
+	if (espi_receive_vwire(espi_dev, signal, &level)) {
+		LOG_DBG("Espi: Failed to the espi GPIO level\n");
+		return 0;
+	}
+
+	LOG_DBG("Espi: GPIO level = %d\n", level);
+	return level;
+}
+
+void ndsx_espi_configure(void)
+{
+	struct espi_cfg cfg = {
+		.io_caps = ESPI_IO_MODE_SINGLE_LINE,
+		.channel_caps = ESPI_CHANNEL_VWIRE |
+			ESPI_CHANNEL_PERIPHERAL |
+			ESPI_CHANNEL_OOB,
+		/* ESPI_FREQ_MHZ */
+		.max_freq = DT_INST_PROP(0, pwrseq_espi_max_freq),
+	};
+
+	if (!device_is_ready(espi_dev))	{
+		LOG_ERR("Espi device is not ready");
+		return;
+	}
+
+	if (espi_config(espi_dev, &cfg)) {
+		LOG_ERR("Failed to configure eSPI");
+		return;
+	}
+
+	/* Configure handler for eSPI events */
+	espi_init_callback(&espi_bus_cb, espi_bus_reset_handler,
+						ESPI_BUS_RESET);
+	espi_add_callback(espi_dev, &espi_bus_cb);
+
+	espi_init_callback(&espi_chan_cb, espi_bus_channel_handler,
+				ESPI_BUS_EVENT_CHANNEL_READY);
+	espi_add_callback(espi_dev, &espi_chan_cb);
+
+	espi_init_callback(&espi_vw_cb, espi_bus_vw_handler,
+				ESPI_BUS_EVENT_VWIRE_RECEIVED);
+	espi_add_callback(espi_dev, &espi_vw_cb);
+}