1 files changed, 407 insertions, 0 deletions
diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
new file mode 100644
index 000000000..ec733f683
--- /dev/null
+++ b/drivers/platform/chrome/cros_ec.c
@@ -0,0 +1,407 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ChromeOS EC multi-function device
+ *
+ * Copyright (C) 2012 Google, Inc
+ *
+ * The ChromeOS EC multi function device is used to mux all the requests
+ * to the EC device for its multiple features: keyboard controller,
+ * battery charging and regulator control, firmware update.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+
+#include "cros_ec.h"
+
+static struct cros_ec_platform ec_p = {
+	.ec_name = CROS_EC_DEV_NAME,
+	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
+};
+
+static struct cros_ec_platform pd_p = {
+	.ec_name = CROS_EC_DEV_PD_NAME,
+	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
+};
+
+/**
+ * cros_ec_irq_handler() - top half part of the interrupt handler
+ * @irq: IRQ id
+ * @data: (ec_dev) Device with events to process.
+ *
+ * Return: Wakeup the bottom half
+ */
+static irqreturn_t cros_ec_irq_handler(int irq, void *data)
+{
+	struct cros_ec_device *ec_dev = data;
+
+	ec_dev->last_event_time = cros_ec_get_time_ns();
+
+	return IRQ_WAKE_THREAD;
+}
+
+/**
+ * cros_ec_handle_event() - process and forward pending events on EC
+ * @ec_dev: Device with events to process.
+ *
+ * Call this function in a loop when the kernel is notified that the EC has
+ * pending events.
+ *
+ * Return: true if more events are still pending and this function should be
+ * called again.
+ */
+static bool cros_ec_handle_event(struct cros_ec_device *ec_dev)
+{
+	bool wake_event;
+	bool ec_has_more_events;
+	int ret;
+
+	ret = cros_ec_get_next_event(ec_dev, &wake_event, &ec_has_more_events);
+
+	/*
+	 * Signal only if wake host events or any interrupt if
+	 * cros_ec_get_next_event() returned an error (default value for
+	 * wake_event is true)
+	 */
+	if (wake_event && device_may_wakeup(ec_dev->dev))
+		pm_wakeup_event(ec_dev->dev, 0);
+
+	if (ret > 0)
+		blocking_notifier_call_chain(&ec_dev->event_notifier,
+					     0, ec_dev);
+
+	return ec_has_more_events;
+}
+
+/**
+ * cros_ec_irq_thread() - bottom half part of the interrupt handler
+ * @irq: IRQ id
+ * @data: (ec_dev) Device with events to process.
+ *
+ * Return: Interrupt handled.
+ */
+irqreturn_t cros_ec_irq_thread(int irq, void *data)
+{
+	struct cros_ec_device *ec_dev = data;
+	bool ec_has_more_events;
+
+	do {
+		ec_has_more_events = cros_ec_handle_event(ec_dev);
+	} while (ec_has_more_events);
+
+	return IRQ_HANDLED;
+}
+EXPORT_SYMBOL(cros_ec_irq_thread);
+
+static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
+{
+	int ret;
+	struct {
+		struct cros_ec_command msg;
+		union {
+			struct ec_params_host_sleep_event req0;
+			struct ec_params_host_sleep_event_v1 req1;
+			struct ec_response_host_sleep_event_v1 resp1;
+		} u;
+	} __packed buf;
+
+	memset(&buf, 0, sizeof(buf));
+
+	if (ec_dev->host_sleep_v1) {
+		buf.u.req1.sleep_event = sleep_event;
+		buf.u.req1.suspend_params.sleep_timeout_ms =
+				ec_dev->suspend_timeout_ms;
+
+		buf.msg.outsize = sizeof(buf.u.req1);
+		if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) ||
+		    (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME))
+			buf.msg.insize = sizeof(buf.u.resp1);
+
+		buf.msg.version = 1;
+
+	} else {
+		buf.u.req0.sleep_event = sleep_event;
+		buf.msg.outsize = sizeof(buf.u.req0);
+	}
+
+	buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;
+
+	ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
+	/* Report failure to transition to system wide suspend with a warning. */
+	if (ret >= 0 && ec_dev->host_sleep_v1 &&
+	    (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME ||
+	     sleep_event == HOST_SLEEP_EVENT_S3_RESUME)) {
+		ec_dev->last_resume_result =
+			buf.u.resp1.resume_response.sleep_transitions;
+
+		WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions &
+			  EC_HOST_RESUME_SLEEP_TIMEOUT,
+			  "EC detected sleep transition timeout. Total sleep transitions: %d",
+			  buf.u.resp1.resume_response.sleep_transitions &
+			  EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK);
+	}
+
+	return ret;
+}
+
+static int cros_ec_ready_event(struct notifier_block *nb,
+			       unsigned long queued_during_suspend,
+			       void *_notify)
+{
+	struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device,
+						     notifier_ready);
+	u32 host_event = cros_ec_get_host_event(ec_dev);
+
+	if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) {
+		mutex_lock(&ec_dev->lock);
+		cros_ec_query_all(ec_dev);
+		mutex_unlock(&ec_dev->lock);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
+/**
+ * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
+ * @ec_dev: Device to register.
+ *
+ * Before calling this, allocate a pointer to a new device and then fill
+ * in all the fields up to the --private-- marker.
+ *
+ * Return: 0 on success or negative error code.
+ */
+int cros_ec_register(struct cros_ec_device *ec_dev)
+{
+	struct device *dev = ec_dev->dev;
+	int err = 0;
+
+	BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
+
+	ec_dev->max_request = sizeof(struct ec_params_hello);
+	ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
+	ec_dev->max_passthru = 0;
+	ec_dev->ec = NULL;
+	ec_dev->pd = NULL;
+	ec_dev->suspend_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT;
+
+	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
+	if (!ec_dev->din)
+		return -ENOMEM;
+
+	ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
+	if (!ec_dev->dout)
+		return -ENOMEM;
+
+	mutex_init(&ec_dev->lock);
+
+	err = cros_ec_query_all(ec_dev);
+	if (err) {
+		dev_err(dev, "Cannot identify the EC: error %d\n", err);
+		return err;
+	}
+
+	if (ec_dev->irq > 0) {
+		err = devm_request_threaded_irq(dev, ec_dev->irq,
+						cros_ec_irq_handler,
+						cros_ec_irq_thread,
+						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+						"chromeos-ec", ec_dev);
+		if (err) {
+			dev_err(dev, "Failed to request IRQ %d: %d\n",
+				ec_dev->irq, err);
+			return err;
+		}
+	}
+
+	/* Register a platform device for the main EC instance */
+	ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev",
+					PLATFORM_DEVID_AUTO, &ec_p,
+					sizeof(struct cros_ec_platform));
+	if (IS_ERR(ec_dev->ec)) {
+		dev_err(ec_dev->dev,
+			"Failed to create CrOS EC platform device\n");
+		return PTR_ERR(ec_dev->ec);
+	}
+
+	if (ec_dev->max_passthru) {
+		/*
+		 * Register a platform device for the PD behind the main EC.
+		 * We make the following assumptions:
+		 * - behind an EC, we have a pd
+		 * - only one device added.
+		 * - the EC is responsive at init time (it is not true for a
+		 *   sensor hub).
+		 */
+		ec_dev->pd = platform_device_register_data(ec_dev->dev,
+					"cros-ec-dev",
+					PLATFORM_DEVID_AUTO, &pd_p,
+					sizeof(struct cros_ec_platform));
+		if (IS_ERR(ec_dev->pd)) {
+			dev_err(ec_dev->dev,
+				"Failed to create CrOS PD platform device\n");
+			err = PTR_ERR(ec_dev->pd);
+			goto exit;
+		}
+	}
+
+	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
+		err = devm_of_platform_populate(dev);
+		if (err) {
+			dev_err(dev, "Failed to register sub-devices\n");
+			goto exit;
+		}
+	}
+
+	/*
+	 * Clear sleep event - this will fail harmlessly on platforms that
+	 * don't implement the sleep event host command.
+	 */
+	err = cros_ec_sleep_event(ec_dev, 0);
+	if (err < 0)
+		dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec\n",
+			err);
+
+	if (ec_dev->mkbp_event_supported) {
+		/*
+		 * Register the notifier for EC_HOST_EVENT_INTERFACE_READY
+		 * event.
+		 */
+		ec_dev->notifier_ready.notifier_call = cros_ec_ready_event;
+		err = blocking_notifier_chain_register(&ec_dev->event_notifier,
+						      &ec_dev->notifier_ready);
+		if (err)
+			goto exit;
+	}
+
+	dev_info(dev, "Chrome EC device registered\n");
+
+	/*
+	 * Unlock EC that may be waiting for AP to process MKBP events.
+	 * If the AP takes to long to answer, the EC would stop sending events.
+	 */
+	if (ec_dev->mkbp_event_supported)
+		cros_ec_irq_thread(0, ec_dev);
+
+	return 0;
+exit:
+	platform_device_unregister(ec_dev->ec);
+	platform_device_unregister(ec_dev->pd);
+	return err;
+}
+EXPORT_SYMBOL(cros_ec_register);
+
+/**
+ * cros_ec_unregister() - Remove a ChromeOS EC.
+ * @ec_dev: Device to unregister.
+ *
+ * Call this to deregister a ChromeOS EC, then clean up any private data.
+ *
+ * Return: 0 on success or negative error code.
+ */
+void cros_ec_unregister(struct cros_ec_device *ec_dev)
+{
+	if (ec_dev->pd)
+		platform_device_unregister(ec_dev->pd);
+	platform_device_unregister(ec_dev->ec);
+}
+EXPORT_SYMBOL(cros_ec_unregister);
+
+#ifdef CONFIG_PM_SLEEP
+/**
+ * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
+ * @ec_dev: Device to suspend.
+ *
+ * This can be called by drivers to handle a suspend event.
+ *
+ * Return: 0 on success or negative error code.
+ */
+int cros_ec_suspend(struct cros_ec_device *ec_dev)
+{
+	struct device *dev = ec_dev->dev;
+	int ret;
+	u8 sleep_event;
+
+	sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
+		      HOST_SLEEP_EVENT_S3_SUSPEND :
+		      HOST_SLEEP_EVENT_S0IX_SUSPEND;
+
+	ret = cros_ec_sleep_event(ec_dev, sleep_event);
+	if (ret < 0)
+		dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec\n",
+			ret);
+
+	if (device_may_wakeup(dev))
+		ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
+	else
+		ec_dev->wake_enabled = false;
+
+	disable_irq(ec_dev->irq);
+	ec_dev->suspended = true;
+
+	return 0;
+}
+EXPORT_SYMBOL(cros_ec_suspend);
+
+static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
+{
+	bool wake_event;
+
+	while (ec_dev->mkbp_event_supported &&
+	       cros_ec_get_next_event(ec_dev, &wake_event, NULL) > 0) {
+		blocking_notifier_call_chain(&ec_dev->event_notifier,
+					     1, ec_dev);
+
+		if (wake_event && device_may_wakeup(ec_dev->dev))
+			pm_wakeup_event(ec_dev->dev, 0);
+	}
+}
+
+/**
+ * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
+ * @ec_dev: Device to resume.
+ *
+ * This can be called by drivers to handle a resume event.
+ *
+ * Return: 0 on success or negative error code.
+ */
+int cros_ec_resume(struct cros_ec_device *ec_dev)
+{
+	int ret;
+	u8 sleep_event;
+
+	ec_dev->suspended = false;
+	enable_irq(ec_dev->irq);
+
+	sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
+		      HOST_SLEEP_EVENT_S3_RESUME :
+		      HOST_SLEEP_EVENT_S0IX_RESUME;
+
+	ret = cros_ec_sleep_event(ec_dev, sleep_event);
+	if (ret < 0)
+		dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n",
+			ret);
+
+	if (ec_dev->wake_enabled)
+		disable_irq_wake(ec_dev->irq);
+
+	/*
+	 * Let the mfd devices know about events that occur during
+	 * suspend. This way the clients know what to do with them.
+	 */
+	cros_ec_report_events_during_suspend(ec_dev);
+
+
+	return 0;
+}
+EXPORT_SYMBOL(cros_ec_resume);
+
+#endif
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ChromeOS EC core driver");