media: renesas: vsp1: Add support to deassert/assert reset line

As the resets DT property is mandatory, and is present in all .dtsi
in mainline, add support to perform deassert/assert using reference
counted reset handle.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/media/platform/renesas/vsp1/vsp1.h b/drivers/media/platform/renesas/vsp1/vsp1.h
index 37cf33c..baf898d 100644 (file)
--- a/drivers/media/platform/renesas/vsp1/vsp1.h
+++ b/drivers/media/platform/renesas/vsp1/vsp1.h
@@ -22,6 +22,7 @@
 struct clk;
 struct device;
 struct rcar_fcp_device;
+struct reset_control;
 
 struct vsp1_drm;
 struct vsp1_entity;
@@ -79,6 +80,7 @@ struct vsp1_device {
        void __iomem *mmio;
        struct rcar_fcp_device *fcp;
        struct device *bus_master;
+       struct reset_control *rstc;
 
        struct vsp1_brx *brs;
        struct vsp1_brx *bru;

diff --git a/drivers/media/platform/renesas/vsp1/vsp1_drv.c b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
index 1f73c48..ef4bcf8 100644 (file)
--- a/drivers/media/platform/renesas/vsp1/vsp1_drv.c
+++ b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
@@ -16,6 +16,7 @@
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include <linux/videodev2.h>
 
 #include <media/rcar-fcp.h>
@@ -622,6 +623,7 @@ static int __maybe_unused vsp1_pm_runtime_suspend(struct device *dev)
        struct vsp1_device *vsp1 = dev_get_drvdata(dev);
 
        rcar_fcp_disable(vsp1->fcp);
+       reset_control_assert(vsp1->rstc);
 
        return 0;
 }
@@ -631,13 +633,31 @@ static int __maybe_unused vsp1_pm_runtime_resume(struct device *dev)
        struct vsp1_device *vsp1 = dev_get_drvdata(dev);
        int ret;
 
+       ret = reset_control_deassert(vsp1->rstc);
+       if (ret < 0)
+               return ret;
+
        if (vsp1->info) {
+               /*
+                * On R-Car Gen2 and RZ/G1, vsp1 register access after deassert
+                * can cause lock-up. It is a special case and needs some delay
+                * to avoid this lock-up.
+                */
+               if (vsp1->info->gen == 2)
+                       udelay(1);
+
                ret = vsp1_device_init(vsp1);
                if (ret < 0)
-                       return ret;
+                       goto done;
        }
 
-       return rcar_fcp_enable(vsp1->fcp);
+       ret = rcar_fcp_enable(vsp1->fcp);
+
+done:
+       if (ret < 0)
+               reset_control_assert(vsp1->rstc);
+
+       return ret;
 }
 
 static const struct dev_pm_ops vsp1_pm_ops = {
@@ -825,6 +845,11 @@ static int vsp1_probe(struct platform_device *pdev)
        if (irq < 0)
                return irq;
 
+       vsp1->rstc = devm_reset_control_get_shared(&pdev->dev, NULL);
+       if (IS_ERR(vsp1->rstc))
+               return dev_err_probe(&pdev->dev, PTR_ERR(vsp1->rstc),
+                                    "failed to get reset control\n");
+
        /* FCP (optional). */
        fcp_node = of_parse_phandle(pdev->dev.of_node, "renesas,fcp", 0);
        if (fcp_node) {