With the blamed commit it seems that lan966x doesn't seem to boot
anymore when the internal CPU is used.
The reason seems to be the usage of the devm_of_iomap, if we replace
this with devm_ioremap, this seems to fix the issue as we use the same
region also for other devices.

Fixes: 0426a920d6269c ("reset: mchp: sparx5: Map cpu-syscon locally in case of LAN966x")
Reviewed-by: Herve Codina <herve.codina@bootlin.com>
Tested-by: Herve Codina <herve.codina@bootlin.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
v3->v4:
- update commit message to match the actual changes
- add comment explaining why we can't use devm_of_iomap
v2->v3:
- forward error from of_address_to_resource
- use devm_ioremap instead of_iomap
v1->v2:
- make sure to use iounmap when driver is removed
---
 drivers/reset/reset-microchip-sparx5.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/reset/reset-microchip-sparx5.c b/drivers/reset/reset-microchip-sparx5.c
index aa5464be7053b..6d3e75b33260e 100644
--- a/drivers/reset/reset-microchip-sparx5.c
+++ b/drivers/reset/reset-microchip-sparx5.c
@@ -8,6 +8,7 @@
  */
 #include <linux/mfd/syscon.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
@@ -72,14 +73,22 @@ static struct regmap *mchp_lan966x_syscon_to_regmap(struct device *dev,
 						    struct device_node *syscon_np)
 {
 	struct regmap_config regmap_config = mchp_lan966x_syscon_regmap_config;
-	resource_size_t size;
+	struct resource res;
 	void __iomem *base;
+	int err;
+
+	err = of_address_to_resource(syscon_np, 0, &res);
+	if (err)
+		return ERR_PTR(err);
 
-	base = devm_of_iomap(dev, syscon_np, 0, &size);
-	if (IS_ERR(base))
-		return ERR_CAST(base);
+	/* It is not possible to use devm_of_iomap because this resource is
+	 * shared with other drivers.
+	 */
+	base = devm_ioremap(dev, res.start, resource_size(&res));
+	if (!base)
+		return ERR_PTR(-ENOMEM);
 
-	regmap_config.max_register = size - 4;
+	regmap_config.max_register =  resource_size(&res) - 4;
 
 	return devm_regmap_init_mmio(dev, base, &regmap_config);
 }
-- 
2.34.1

On Do, 2025-02-27 at 11:55 +0100, Horatiu Vultur wrote:
> With the blamed commit it seems that lan966x doesn't seem to boot
> anymore when the internal CPU is used.
> The reason seems to be the usage of the devm_of_iomap, if we replace
> this with devm_ioremap, this seems to fix the issue as we use the same
> region also for other devices.
> 
> Fixes: 0426a920d6269c ("reset: mchp: sparx5: Map cpu-syscon locally in case of LAN966x")
> Reviewed-by: Herve Codina <herve.codina@bootlin.com>
> Tested-by: Herve Codina <herve.codina@bootlin.com>
> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>

Applied to reset/fixes, thanks!

[1/1] reset: mchp: sparx5: Fix for lan966x
      https://git.pengutronix.de/cgit/pza/linux/commit/?id=0e2268f88bb2

regards
Philipp

On Do, 2025-02-27 at 11:55 +0100, Horatiu Vultur wrote:
> With the blamed commit it seems that lan966x doesn't seem to boot
> anymore when the internal CPU is used.
> The reason seems to be the usage of the devm_of_iomap, if we replace
> this with devm_ioremap, this seems to fix the issue as we use the same
> region also for other devices.
> 
> Fixes: 0426a920d6269c ("reset: mchp: sparx5: Map cpu-syscon locally in case of LAN966x")
> Reviewed-by: Herve Codina <herve.codina@bootlin.com>
> Tested-by: Herve Codina <herve.codina@bootlin.com>
> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp