greybus: pwm: Add runtime_pm support

Add runtime pm support for the pmw driver.

Testing Done: Set the parameters of pwm0, and enable.
Disable pwm0 and let the module enter standby.
Enable pwm0, and observe that with an oscilloscope
that the wave form is the same as before.
Signed-off-by: Axel Haslam <haslam_axel@projectara.com>
Signed-off-by: David Lin <dtwlin@google.com>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Alex Elder <elder@linaro.org>

drivers/staging/greybus/pwm.c

@@ -43,32 +43,58 @@ static int gb_pwm_activate_operation(struct gb_pwm_chip *pwmc,
 				     u8 which)
 {
 	struct gb_pwm_activate_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
 
 	if (which > pwmc->pwm_max)
 		return -EINVAL;
 
 	request.which = which;
-	return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ACTIVATE,
-				 &request, sizeof(request), NULL, 0);
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		return ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ACTIVATE,
+				&request, sizeof(request), NULL, 0);
+
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
 }
 
 static int gb_pwm_deactivate_operation(struct gb_pwm_chip *pwmc,
 				       u8 which)
 {
 	struct gb_pwm_deactivate_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
 
 	if (which > pwmc->pwm_max)
 		return -EINVAL;
 
 	request.which = which;
-	return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DEACTIVATE,
-				 &request, sizeof(request), NULL, 0);
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		return ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DEACTIVATE,
+				&request, sizeof(request), NULL, 0);
+
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
 }
 
 static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc,
 				   u8 which, u32 duty, u32 period)
 {
 	struct gb_pwm_config_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
 
 	if (which > pwmc->pwm_max)
 		return -EINVAL;
@@ -76,48 +102,90 @@ static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc,
 	request.which = which;
 	request.duty = cpu_to_le32(duty);
 	request.period = cpu_to_le32(period);
-	return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_CONFIG,
-				 &request, sizeof(request), NULL, 0);
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		return ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_CONFIG,
+				&request, sizeof(request), NULL, 0);
+
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
 }
 
 static int gb_pwm_set_polarity_operation(struct gb_pwm_chip *pwmc,
 					 u8 which, u8 polarity)
 {
 	struct gb_pwm_polarity_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
 
 	if (which > pwmc->pwm_max)
 		return -EINVAL;
 
 	request.which = which;
 	request.polarity = polarity;
-	return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_POLARITY,
-				 &request, sizeof(request), NULL, 0);
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		return ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_POLARITY,
+				&request, sizeof(request), NULL, 0);
+
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
 }
 
 static int gb_pwm_enable_operation(struct gb_pwm_chip *pwmc,
 				   u8 which)
 {
 	struct gb_pwm_enable_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
 
 	if (which > pwmc->pwm_max)
 		return -EINVAL;
 
 	request.which = which;
-	return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ENABLE,
-				 &request, sizeof(request), NULL, 0);
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		return ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ENABLE,
+				&request, sizeof(request), NULL, 0);
+	if (ret)
+		gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
 }
 
 static int gb_pwm_disable_operation(struct gb_pwm_chip *pwmc,
 				    u8 which)
 {
 	struct gb_pwm_disable_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
 
 	if (which > pwmc->pwm_max)
 		return -EINVAL;
 
 	request.which = which;
-	return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DISABLE,
-				 &request, sizeof(request), NULL, 0);
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DISABLE,
+				&request, sizeof(request), NULL, 0);
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
 }
 
 static int gb_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
@@ -225,6 +293,7 @@ static int gb_pwm_probe(struct gbphy_device *gbphy_dev,
 		goto exit_connection_disable;
 	}
 
+	gbphy_runtime_put_autosuspend(gbphy_dev);
 	return 0;
 
 exit_connection_disable:
@@ -240,6 +309,11 @@ static void gb_pwm_remove(struct gbphy_device *gbphy_dev)
 {
 	struct gb_pwm_chip *pwmc = gb_gbphy_get_data(gbphy_dev);
 	struct gb_connection *connection = pwmc->connection;
+	int ret;
+
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		gbphy_runtime_get_noresume(gbphy_dev);
 
 	pwmchip_remove(&pwmc->chip);
 	gb_connection_disable(connection);