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@xxxxxxxxxxxxxx>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
---
v10->v11:
* To avoid lock-up on R-Car Gen2, added poll for reset status after deassert.
v9->v10:
* Moved {deassert,assert} calls to vsp1_pm_runtime_{resume,suspend}
v8->v9:
* No change
v7->v8:
* No Change
v6->v7:
* No change
v5->v6:
* Rebased to media_staging and updated commit header
* Added Rb tag from Laurent
* Added forward declaration for struct reset_control
* Updated vsp1_device_get() with changes suggested by Laurent
* Updated error message for reset_control_get form ctrl->control.
v4->v5:
* Added Rb tag from Geert
v3->v4:
* Restored error check for pm_runtime_resume_and_get and calls
assert() in case of failure.
v2->v3:
* Added Rb tag from Philipp
* If reset_control_deassert() failed, return ret directly.
v1->v2:
* Used reference counted reset handle to perform deassert/assert
RFC->v1:
* Added reset support as separate patch
* Moved rstc just after the bus_master field in struct vsp1_device
RFC:
* https://patchwork.kernel.org/project/linux-renesas-soc/patch/20220112174612.10773-21-biju.das.jz@xxxxxxxxxxxxxx/
---
drivers/media/platform/renesas/vsp1/vsp1.h | 2 ++
.../media/platform/renesas/vsp1/vsp1_drv.c | 32 +++++++++++++++++--
2 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/drivers/media/platform/renesas/vsp1/vsp1.h b/drivers/media/platform/renesas/vsp1/vsp1.h
index 37cf33c7e6ca..baf898d577ec 100644
--- 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 1f73c48eb738..466826db29f9 100644
--- a/drivers/media/platform/renesas/vsp1/vsp1_drv.c
+++ b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
@@ -11,11 +11,13 @@
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/interrupt.h>
+#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#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 +624,7 @@ 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 +634,33 @@ 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;
+
+ /*
+ * On R-Car Gen2, vsp1 register access after deassert can cause
+ * lock-up. Therefore, we need to poll the status of the reset to
+ * avoid lock-up.
+ */
+ ret = read_poll_timeout_atomic(reset_control_status, ret, ret == 0, 1,
+ 100, false, vsp1->rstc);
+ if (ret < 0)
+ goto done;
+
if (vsp1->info) {
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 +848,11 @@ 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) {
--
2.25.1
