[PATCH v2 2/4] platform/chrome: cros_ec_lightbar - Control of suspend/resume lightbar sequence

[Enric Balletbo i Serra]

From: Eric Caruso <ejcaruso@xxxxxxxxxxxx>

Don't let EC control suspend/resume sequence. If the EC controls the
lightbar and sets the sequence when it notices the chipset transitioning
between states, we can't make exceptions for cases where we don't want
to activate the lightbar. Instead, let's move the suspend/resume
notifications into the kernel so we can selectively play the sequences.

Signed-off-by: Eric Caruso <ejcaruso@xxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <groeck@xxxxxxxxxxxx>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
---
 drivers/platform/chrome/cros_ec_dev.c      | 38 +++++++++++++
 drivers/platform/chrome/cros_ec_dev.h      |  6 +++
 drivers/platform/chrome/cros_ec_lightbar.c | 85 ++++++++++++++++++++++++++++--
 include/linux/mfd/cros_ec_commands.h       | 11 +++-
 4 files changed, 135 insertions(+), 5 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index ebe029d..ef04523 100644
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -21,6 +21,7 @@
 #include <linux/mfd/core.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/pm.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 
@@ -463,6 +464,10 @@ static int ec_device_probe(struct platform_device *pdev)
 	if (cros_ec_check_features(ec, EC_FEATURE_RTC))
 		cros_ec_rtc_register(ec);
 
+	/* Take control of the lightbar from the EC. */
+	if (ec_has_lightbar(ec))
+		lb_manual_suspend_ctrl(ec, 1);
+
 	return 0;
 
 dev_reg_failed:
@@ -477,6 +482,11 @@ static int ec_device_probe(struct platform_device *pdev)
 static int ec_device_remove(struct platform_device *pdev)
 {
 	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
+
+	/* Let the EC take over the lightbar again. */
+	if (ec_has_lightbar(ec))
+		lb_manual_suspend_ctrl(ec, 0);
+
 	cdev_del(&ec->cdev);
 	device_unregister(&ec->class_dev);
 	return 0;
@@ -488,9 +498,37 @@ static const struct platform_device_id cros_ec_id[] = {
 };
 MODULE_DEVICE_TABLE(platform, cros_ec_id);
 
+static int ec_device_suspend(struct device *dev)
+{
+	struct cros_ec_dev *ec = dev_get_drvdata(dev);
+
+	if (ec_has_lightbar(ec))
+		lb_suspend(ec);
+
+	return 0;
+}
+
+static int ec_device_resume(struct device *dev)
+{
+	struct cros_ec_dev *ec = dev_get_drvdata(dev);
+
+	if (ec_has_lightbar(ec))
+		lb_resume(ec);
+
+	return 0;
+}
+
+static const struct dev_pm_ops cros_ec_dev_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend = ec_device_suspend,
+	.resume = ec_device_resume,
+#endif
+};
+
 static struct platform_driver cros_ec_dev_driver = {
 	.driver = {
 		.name = "cros-ec-ctl",
+		.pm = &cros_ec_dev_pm_ops,
 	},
 	.probe = ec_device_probe,
 	.remove = ec_device_remove,
diff --git a/drivers/platform/chrome/cros_ec_dev.h b/drivers/platform/chrome/cros_ec_dev.h
index bfd2c84..45e9453 100644
--- a/drivers/platform/chrome/cros_ec_dev.h
+++ b/drivers/platform/chrome/cros_ec_dev.h
@@ -43,4 +43,10 @@ struct cros_ec_readmem {
 #define CROS_EC_DEV_IOCXCMD   _IOWR(CROS_EC_DEV_IOC, 0, struct cros_ec_command)
 #define CROS_EC_DEV_IOCRDMEM  _IOWR(CROS_EC_DEV_IOC, 1, struct cros_ec_readmem)
 
+/* Lightbar utilities */
+extern bool ec_has_lightbar(struct cros_ec_dev *ec);
+extern int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable);
+extern int lb_suspend(struct cros_ec_dev *ec);
+extern int lb_resume(struct cros_ec_dev *ec);
+
 #endif /* _CROS_EC_DEV_H_ */
diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
index 2667505..4df379d 100644
--- a/drivers/platform/chrome/cros_ec_lightbar.c
+++ b/drivers/platform/chrome/cros_ec_lightbar.c
@@ -341,6 +341,80 @@ static ssize_t sequence_show(struct device *dev,
 	return ret;
 }
 
+static int lb_send_empty_cmd(struct cros_ec_dev *ec, uint8_t cmd)
+{
+	struct ec_params_lightbar *param;
+	struct cros_ec_command *msg;
+	int ret;
+
+	msg = alloc_lightbar_cmd_msg(ec);
+	if (!msg)
+		return -ENOMEM;
+
+	param = (struct ec_params_lightbar *)msg->data;
+	param->cmd = cmd;
+
+	ret = lb_throttle();
+	if (ret)
+		goto error;
+
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
+	if (ret < 0)
+		goto error;
+	if (msg->result != EC_RES_SUCCESS) {
+		ret = -EINVAL;
+		goto error;
+	}
+	ret = 0;
+error:
+	kfree(msg);
+
+	return ret;
+}
+
+int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable)
+{
+	struct ec_params_lightbar *param;
+	struct cros_ec_command *msg;
+	int ret;
+
+	msg = alloc_lightbar_cmd_msg(ec);
+	if (!msg)
+		return -ENOMEM;
+
+	param = (struct ec_params_lightbar *)msg->data;
+
+	param->cmd = LIGHTBAR_CMD_MANUAL_SUSPEND_CTRL;
+	param->manual_suspend_ctrl.enable = enable;
+
+	ret = lb_throttle();
+	if (ret)
+		goto error;
+
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
+	if (ret < 0)
+		goto error;
+	if (msg->result != EC_RES_SUCCESS) {
+		ret = -EINVAL;
+		goto error;
+	}
+	ret = 0;
+error:
+	kfree(msg);
+
+	return ret;
+}
+
+int lb_suspend(struct cros_ec_dev *ec)
+{
+	return lb_send_empty_cmd(ec, LIGHTBAR_CMD_SUSPEND);
+}
+
+int lb_resume(struct cros_ec_dev *ec)
+{
+	return lb_send_empty_cmd(ec, LIGHTBAR_CMD_RESUME);
+}
+
 static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
 			      const char *buf, size_t count)
 {
@@ -473,6 +547,11 @@ static struct attribute *__lb_cmds_attrs[] = {
 	NULL,
 };
 
+bool ec_has_lightbar(struct cros_ec_dev *ec)
+{
+	return !!get_lightbar_version(ec, NULL, NULL);
+}
+
 static umode_t cros_ec_lightbar_attrs_are_visible(struct kobject *kobj,
 						  struct attribute *a, int n)
 {
@@ -489,10 +568,10 @@ static umode_t cros_ec_lightbar_attrs_are_visible(struct kobject *kobj,
 		return 0;
 
 	/* Only instantiate this stuff if the EC has a lightbar */
-	if (get_lightbar_version(ec, NULL, NULL))
+	if (ec_has_lightbar(ec))
 		return a->mode;
-	else
-		return 0;
+
+	return 0;
 }
 
 struct attribute_group cros_ec_lightbar_attr_group = {
diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index efc78bd..64138fd 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -1176,7 +1176,7 @@ struct ec_params_lightbar {
 		struct {
 			/* no args */
 		} dump, off, on, init, get_seq, get_params_v0, get_params_v1,
-			version, get_brightness, get_demo;
+			version, get_brightness, get_demo, suspend, resume;
 
 		struct {
 			uint8_t num;
@@ -1194,6 +1194,10 @@ struct ec_params_lightbar {
 			uint8_t led;
 		} get_rgb;
 
+		struct {
+			uint8_t enable;
+		} manual_suspend_ctrl;
+
 		struct lightbar_params_v0 set_params_v0;
 		struct lightbar_params_v1 set_params_v1;
 		struct lightbar_program set_program;
@@ -1230,7 +1234,7 @@ struct ec_response_lightbar {
 			/* no return params */
 		} off, on, init, set_brightness, seq, reg, set_rgb,
 			demo, set_params_v0, set_params_v1,
-			set_program;
+			set_program, manual_suspend_ctrl, suspend, resume;
 	};
 } __packed;
 
@@ -1255,6 +1259,9 @@ enum lightbar_command {
 	LIGHTBAR_CMD_GET_PARAMS_V1 = 16,
 	LIGHTBAR_CMD_SET_PARAMS_V1 = 17,
 	LIGHTBAR_CMD_SET_PROGRAM = 18,
+	LIGHTBAR_CMD_MANUAL_SUSPEND_CTRL = 19,
+	LIGHTBAR_CMD_SUSPEND = 20,
+	LIGHTBAR_CMD_RESUME = 21,
 	LIGHTBAR_NUM_CMDS
 };
 
-- 
2.9.3