mfd: cros_ec: Send suspend state notification to EC

Notify EC when going to or returning from suspend so that proper actions
related to wake events can be taken.

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index ad48633c9a47a482cc86a8aea88e3a6a1576452e..b8a50808bedbbbf30f530321ce44c5cf0285b623 100644 (file)
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -23,6 +23,7 @@
 #include <linux/module.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/cros_ec.h>
+#include <linux/suspend.h>
 #include <asm/unaligned.h>
 
 #define CROS_EC_DEV_EC_INDEX 0
@@ -65,6 +66,24 @@ static irqreturn_t ec_irq_thread(int irq, void *data)
        return IRQ_HANDLED;
 }
 
+static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
+{
+       struct {
+               struct cros_ec_command msg;
+               struct ec_params_host_sleep_event req;
+       } __packed buf;
+
+       memset(&buf, 0, sizeof(buf));
+
+       buf.req.sleep_event = sleep_event;
+
+       buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;
+       buf.msg.version = 0;
+       buf.msg.outsize = sizeof(buf.req);
+
+       return cros_ec_cmd_xfer(ec_dev, &buf.msg);
+}
+
 int cros_ec_register(struct cros_ec_device *ec_dev)
 {
        struct device *dev = ec_dev->dev;
@@ -136,6 +155,15 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
                }
        }
 
+       /*
+        * 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",
+                       err);
+
        dev_info(dev, "Chrome EC device registered\n");
 
        return 0;
@@ -159,6 +187,16 @@ EXPORT_SYMBOL(cros_ec_remove);
 int cros_ec_suspend(struct cros_ec_device *ec_dev)
 {
        struct device *dev = ec_dev->dev;
+       int ret;
+       u8 sleep_event;
+
+       sleep_event = 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 suspend event to ec",
+                       ret);
 
        if (device_may_wakeup(dev))
                ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
@@ -180,9 +218,20 @@ static void cros_ec_drain_events(struct cros_ec_device *ec_dev)
 
 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 = 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",
+                       ret);
+
        /*
         * In some cases, we need to distinguish between events that occur
         * during suspend if the EC is not a wake source. For example,

diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index da1c188562bc90ff39b6c1a6e0d634cd7584fca3..34ecae4d612cdaedf51c0053a12058f8a56cbe84 100644 (file)
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -2547,6 +2547,20 @@ struct ec_params_ext_power_current_limit {
        uint32_t limit; /* in mA */
 } __packed;
 
+/* Inform the EC when entering a sleep state */
+#define EC_CMD_HOST_SLEEP_EVENT 0xa9
+
+enum host_sleep_event {
+       HOST_SLEEP_EVENT_S3_SUSPEND   = 1,
+       HOST_SLEEP_EVENT_S3_RESUME    = 2,
+       HOST_SLEEP_EVENT_S0IX_SUSPEND = 3,
+       HOST_SLEEP_EVENT_S0IX_RESUME  = 4
+};
+
+struct ec_params_host_sleep_event {
+       uint8_t sleep_event;
+} __packed;
+
 /*****************************************************************************/
 /* Smart battery pass-through */