media: hantro: add support for reset lines

Some SoCs like Allwinner H6 use reset lines for resetting Hantro G2. Add
support for them.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/hantro/hantro.h

@@ -16,6 +16,7 @@
 #include <linux/videodev2.h>
 #include <linux/wait.h>
 #include <linux/clk.h>
+#include <linux/reset.h>
 
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
@@ -171,6 +172,7 @@ hantro_vdev_to_func(struct video_device *vdev)
  * @dev:		Pointer to device for convenient logging using
  *			dev_ macros.
  * @clocks:		Array of clock handles.
+ * @resets:		Array of reset handles.
  * @reg_bases:		Mapped addresses of VPU registers.
  * @enc_base:		Mapped address of VPU encoder register for convenience.
  * @dec_base:		Mapped address of VPU decoder register for convenience.
@@ -190,6 +192,7 @@ struct hantro_dev {
 	struct platform_device *pdev;
 	struct device *dev;
 	struct clk_bulk_data *clocks;
+	struct reset_control *resets;
 	void __iomem **reg_bases;
 	void __iomem *enc_base;
 	void __iomem *dec_base;

drivers/staging/media/hantro/hantro_drv.c

@@ -905,6 +905,10 @@ static int hantro_probe(struct platform_device *pdev)
 			return PTR_ERR(vpu->clocks[0].clk);
 	}
 
+	vpu->resets = devm_reset_control_array_get(&pdev->dev, false, true);
+	if (IS_ERR(vpu->resets))
+		return PTR_ERR(vpu->resets);
+
 	num_bases = vpu->variant->num_regs ?: 1;
 	vpu->reg_bases = devm_kcalloc(&pdev->dev, num_bases,
 				      sizeof(*vpu->reg_bases), GFP_KERNEL);
@@ -978,10 +982,16 @@ static int hantro_probe(struct platform_device *pdev)
 	pm_runtime_use_autosuspend(vpu->dev);
 	pm_runtime_enable(vpu->dev);
 
+	ret = reset_control_deassert(vpu->resets);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to deassert resets\n");
+		goto err_pm_disable;
+	}
+
 	ret = clk_bulk_prepare(vpu->variant->num_clocks, vpu->clocks);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to prepare clocks\n");
-		goto err_pm_disable;
+		goto err_rst_assert;
 	}
 
 	ret = v4l2_device_register(&pdev->dev, &vpu->v4l2_dev);
@@ -1037,6 +1047,8 @@ static int hantro_probe(struct platform_device *pdev)
 	v4l2_device_unregister(&vpu->v4l2_dev);
 err_clk_unprepare:
 	clk_bulk_unprepare(vpu->variant->num_clocks, vpu->clocks);
+err_rst_assert:
+	reset_control_assert(vpu->resets);
 err_pm_disable:
 	pm_runtime_dont_use_autosuspend(vpu->dev);
 	pm_runtime_disable(vpu->dev);
@@ -1056,6 +1068,7 @@ static int hantro_remove(struct platform_device *pdev)
 	v4l2_m2m_release(vpu->m2m_dev);
 	v4l2_device_unregister(&vpu->v4l2_dev);
 	clk_bulk_unprepare(vpu->variant->num_clocks, vpu->clocks);
+	reset_control_assert(vpu->resets);
 	pm_runtime_dont_use_autosuspend(vpu->dev);
 	pm_runtime_disable(vpu->dev);
 	return 0;