Re: [PATCH 2/3] mfd: cros_ec: Send suspend state notification to EC

From: Thierry Escande
Date: Wed Jan 04 2017 - 09:18:22 EST


Hi Lee,

On 04/01/2017 10:07, Lee Jones wrote:
On Fri, 16 Dec 2016, Thierry Escande wrote:

From: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>

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@xxxxxxxxxxxx>
Signed-off-by: Thierry Escande <thierry.escande@xxxxxxxxxxxxx>
---
drivers/mfd/cros_ec.c | 49 ++++++++++++++++++++++++++++++++++++
include/linux/mfd/cros_ec_commands.h | 14 +++++++++++
2 files changed, 63 insertions(+)

Can this patch be taken without 3/3?
Yes, both 1st and 2nd patches can be taken without the 3rd one. I'll send a v2 with 3/3 in a separate patch.

Regards,
Thierry


For my own reference:
Acked-for-MFD-by: Lee Jones <lee.jones@xxxxxxxxxx>

diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index ad48633..b8a5080 100644
--- 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 76728ff..4d55132 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -2304,6 +2304,20 @@ 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 */