drm/lima: add pm resume/suspend ops

Add driver pm system and runtime hardware resume/suspend ops.
Note this won't enable runtime pm of the device yet.

v2:
Do clock and power gating when suspend/resume.
Tested-by: Bhushan Shah <bshah@kde.org>
Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200421133551.31481-10-yuq825@gmail.com

drivers/gpu/drm/lima/lima_device.c

@@ -247,6 +247,27 @@ static void lima_fini_ip(struct lima_device *ldev, int index)
 		desc->fini(ip);
 }
 
+static int lima_resume_ip(struct lima_device *ldev, int index)
+{
+	struct lima_ip_desc *desc = lima_ip_desc + index;
+	struct lima_ip *ip = ldev->ip + index;
+	int ret = 0;
+
+	if (ip->present)
+		ret = desc->resume(ip);
+
+	return ret;
+}
+
+static void lima_suspend_ip(struct lima_device *ldev, int index)
+{
+	struct lima_ip_desc *desc = lima_ip_desc + index;
+	struct lima_ip *ip = ldev->ip + index;
+
+	if (ip->present)
+		desc->suspend(ip);
+}
+
 static int lima_init_gp_pipe(struct lima_device *dev)
 {
 	struct lima_sched_pipe *pipe = dev->pipe + lima_pipe_gp;
@@ -441,3 +462,72 @@ void lima_device_fini(struct lima_device *ldev)
 
 	lima_clk_fini(ldev);
 }
+
+int lima_device_resume(struct device *dev)
+{
+	struct lima_device *ldev = dev_get_drvdata(dev);
+	int i, err;
+
+	err = lima_clk_enable(ldev);
+	if (err) {
+		dev_err(dev, "resume clk fail %d\n", err);
+		return err;
+	}
+
+	err = lima_regulator_enable(ldev);
+	if (err) {
+		dev_err(dev, "resume regulator fail %d\n", err);
+		goto err_out0;
+	}
+
+	for (i = 0; i < lima_ip_num; i++) {
+		err = lima_resume_ip(ldev, i);
+		if (err) {
+			dev_err(dev, "resume ip %d fail\n", i);
+			goto err_out1;
+		}
+	}
+
+	err = lima_devfreq_resume(&ldev->devfreq);
+	if (err) {
+		dev_err(dev, "devfreq resume fail\n");
+		goto err_out1;
+	}
+
+	return 0;
+
+err_out1:
+	while (--i >= 0)
+		lima_suspend_ip(ldev, i);
+	lima_regulator_disable(ldev);
+err_out0:
+	lima_clk_disable(ldev);
+	return err;
+}
+
+int lima_device_suspend(struct device *dev)
+{
+	struct lima_device *ldev = dev_get_drvdata(dev);
+	int i, err;
+
+	/* check any task running */
+	for (i = 0; i < lima_pipe_num; i++) {
+		if (atomic_read(&ldev->pipe[i].base.hw_rq_count))
+			return -EBUSY;
+	}
+
+	err = lima_devfreq_suspend(&ldev->devfreq);
+	if (err) {
+		dev_err(dev, "devfreq suspend fail\n");
+		return err;
+	}
+
+	for (i = lima_ip_num - 1; i >= 0; i--)
+		lima_suspend_ip(ldev, i);
+
+	lima_regulator_disable(ldev);
+
+	lima_clk_disable(ldev);
+
+	return 0;
+}

drivers/gpu/drm/lima/lima_device.h

@@ -140,4 +140,7 @@ static inline int lima_poll_timeout(struct lima_ip *ip, lima_poll_func_t func,
 	return 0;
 }
 
+int lima_device_suspend(struct device *dev);
+int lima_device_resume(struct device *dev);
+
 #endif

drivers/gpu/drm/lima/lima_drv.c

@@ -5,6 +5,7 @@
 #include <linux/of_platform.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
+#include <linux/pm_runtime.h>
 #include <drm/drm_ioctl.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_prime.h>
@@ -451,11 +452,17 @@ static const struct of_device_id dt_match[] = {
 };
 MODULE_DEVICE_TABLE(of, dt_match);
 
+static const struct dev_pm_ops lima_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(lima_device_suspend, lima_device_resume, NULL)
+};
+
 static struct platform_driver lima_platform_driver = {
 	.probe      = lima_pdev_probe,
 	.remove     = lima_pdev_remove,
 	.driver     = {
 		.name   = "lima",
+		.pm	= &lima_pm_ops,
 		.of_match_table = dt_match,
 	},
 };