[PATCH] fbdev: wmt_ge_rops: use devm_platform_ioremap_resource()

[PATCH] fbdev: wmt_ge_rops: use devm_platform_ioremap_resource()

[Amin GATTOUT]

Replace the open-coded platform_get_resource() + ioremap() pair with
devm_platform_ioremap_resource(), which requests the memory region and
maps it in a single call, with automatic cleanup on device removal.

Also reset regbase to NULL in remove() so that the single-instance
guard in probe() works correctly if the device is re-probed.

Signed-off-by: Amin GATTOUT <amin.gattout@gmail.com>
---
 drivers/video/fbdev/wmt_ge_rops.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/video/fbdev/wmt_ge_rops.c b/drivers/video/fbdev/wmt_ge_rops.c
index 2bd26bfb2b46..0cf78bcadfa6 100644
--- a/drivers/video/fbdev/wmt_ge_rops.c
+++ b/drivers/video/fbdev/wmt_ge_rops.c
@@ -148,25 +148,15 @@ EXPORT_SYMBOL_GPL(wmt_ge_sync);
 
 static int wmt_ge_rops_probe(struct platform_device *pdev)
 {
-	struct resource *res;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (res == NULL) {
-		dev_err(&pdev->dev, "no I/O memory resource defined\n");
-		return -ENODEV;
-	}
-
 	/* Only one ROP engine is presently supported. */
 	if (unlikely(regbase)) {
 		WARN_ON(1);
 		return -EBUSY;
 	}
 
-	regbase = ioremap(res->start, resource_size(res));
-	if (regbase == NULL) {
-		dev_err(&pdev->dev, "failed to map I/O memory\n");
-		return -EBUSY;
-	}
+	regbase = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(regbase))
+		return PTR_ERR(regbase);
 
 	writel(1, regbase + GE_ENABLE_OFF);
 	printk(KERN_INFO "Enabled support for WMT GE raster acceleration\n");
@@ -176,7 +166,7 @@ static int wmt_ge_rops_probe(struct platform_device *pdev)
 
 static void wmt_ge_rops_remove(struct platform_device *pdev)
 {
-	iounmap(regbase);
+	regbase = NULL;
 }
 
 static const struct of_device_id wmt_dt_ids[] = {

---
base-commit: 11439c4635edd669ae435eec308f4ab8a0804808
change-id: 20260303-master-4dbb344c9a39

Best regards,
-- 
Amin GATTOUT <amin.gattout@gmail.com>

Claude review: fbdev: wmt_ge_rops: use devm_platform_ioremap_resource()

[Claude Code Review Bot]

Overall Series Review

Subject: fbdev: wmt_ge_rops: use devm_platform_ioremap_resource()
Author: Amin GATTOUT <amin.gattout@gmail.com>
Patches: 1
Reviewed: 2026-03-05T13:20:54.380535

---

This is a single-patch cleanup converting `platform_get_resource()` + `ioremap()` to `devm_platform_ioremap_resource()` in the WMT GE raster ops fbdev driver. The conversion is straightforward and the intent is correct, but there is a bug introduced by the error path leaving `regbase` in an invalid state.

---
Generated by Claude Code Patch Reviewer

Claude review: fbdev: wmt_ge_rops: use devm_platform_ioremap_resource()

[Claude Code Review Bot]

Patch Review

**Bug: `regbase` left as ERR_PTR on probe failure**

When `devm_platform_ioremap_resource()` fails, it returns an ERR_PTR value which gets assigned to `regbase`. The function then returns the error code, but `regbase` is left holding a non-NULL error-pointer value. On a subsequent probe attempt (or re-probe), the single-instance guard at line 152:

```c
if (unlikely(regbase)) {
    WARN_ON(1);
    return -EBUSY;
}
```

will see the stale ERR_PTR as non-NULL, fire the WARN_ON, and return `-EBUSY` — permanently blocking the driver from ever probing successfully again.

Fix: reset `regbase` to NULL in the error path:

```c
regbase = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(regbase)) {
    int ret = PTR_ERR(regbase);
    regbase = NULL;
    return ret;
}
```

**Removal of `iounmap()` is correct** — `devm_platform_ioremap_resource()` registers a devres action that automatically unmaps on device removal, so the explicit `iounmap()` must go. Setting `regbase = NULL` in `remove()` is the right thing to do for the re-probe guard.

**Minor: no `dev_err` on failure** — The original code printed `"failed to map I/O memory"` on failure. `devm_platform_ioremap_resource()` does emit its own error messages internally, so dropping the explicit `dev_err` is fine.

**Overall:** The patch needs a v2 to fix the ERR_PTR-in-`regbase` issue on the error path. Otherwise the conversion is clean and correct.

---
Generated by Claude Code Patch Reviewer