[PATCH V2 07/11] mfd: bcm2835-pm: Add support for BCM2711

[Stefan Wahren]

In BCM2711 the new RPiVid ASB took over V3D. The old ASB is still present
with the ISP and H264 bits, and V3D is in the same place in the new ASB
as the old one.

As per the devicetree bindings, BCM2711 will provide both the old and
new ASB resources, so get both of them and pass them into
'bcm2835-power,' which will take care of selecting which one to use
accordingly.

Since the RPiVid ASB's resources were being provided prior to formalizing
the bindings[1], also support the old DT files that didn't use
'reg-names.'

Signed-off-by: Stefan Wahren <stefan.wahren at i2se.com>

[1] See: 7dbe8c62ceeb ("ARM: dts: Add minimal Raspberry Pi 4 support")
---
 drivers/mfd/bcm2835-pm.c       | 21 +++++++++++++++++++++
 include/linux/mfd/bcm2835-pm.h |  1 +
 2 files changed, 22 insertions(+)

diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c
index c1e81a4541d7..e65aee6f9b84 100644
--- a/drivers/mfd/bcm2835-pm.c
+++ b/drivers/mfd/bcm2835-pm.c
@@ -28,6 +28,8 @@ static const struct mfd_cell bcm2835_power_devs[] = {
 static int bcm2835_pm_get_pdata(struct platform_device *pdev,
 				struct bcm2835_pm *pm)
 {
+	bool is_bcm2711 = of_device_is_compatible(pm->dev->of_node, "brcm,bcm2711-pm");
+
 	/* If no 'reg-names' property is found we can assume we're using old
 	 * firmware.
 	 */
@@ -39,6 +41,7 @@ static int bcm2835_pm_get_pdata(struct platform_device *pdev,
 			return PTR_ERR(pm->base);
 
 		pm->asb = devm_platform_ioremap_resource(pdev, 1);
+		pm->rpivid_asb = devm_platform_ioremap_resource(pdev, 2);
 	} else {
 		struct resource *res;
 
@@ -50,11 +53,28 @@ static int bcm2835_pm_get_pdata(struct platform_device *pdev,
 						    "asb");
 		if (res)
 			pm->asb = devm_ioremap_resource(&pdev->dev, res);
+
+		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						    "rpivid_asb");
+		if (res)
+			pm->rpivid_asb = devm_ioremap_resource(&pdev->dev,
+								res);
 	}
 
 	if (IS_ERR(pm->asb))
 		pm->asb = NULL;
 
+	if (IS_ERR(pm->rpivid_asb))
+		pm->rpivid_asb = NULL;
+
+	/* Ensure that rpivid_asb is set only for BCM2711, so subsequent
+	 * driver can rely on this and don't get confused by broken DTB.
+	 */
+	if (pm->rpivid_asb && !is_bcm2711) {
+		dev_err(pm->dev, "Unexpected rpivid_asb register, please fix your DTB.\n");
+		return -EINVAL;
+	}
+
 	return 0;
 }
 
@@ -95,6 +115,7 @@ static int bcm2835_pm_probe(struct platform_device *pdev)
 static const struct of_device_id bcm2835_pm_of_match[] = {
 	{ .compatible = "brcm,bcm2835-pm-wdt", },
 	{ .compatible = "brcm,bcm2835-pm", },
+	{ .compatible = "brcm,bcm2711-pm", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
diff --git a/include/linux/mfd/bcm2835-pm.h b/include/linux/mfd/bcm2835-pm.h
index ed37dc40e82a..f70a810c55f7 100644
--- a/include/linux/mfd/bcm2835-pm.h
+++ b/include/linux/mfd/bcm2835-pm.h
@@ -9,6 +9,7 @@ struct bcm2835_pm {
 	struct device *dev;
 	void __iomem *base;
 	void __iomem *asb;
+	void __iomem *rpivid_asb;
 };
 
 #endif /* BCM2835_MFD_PM_H */
-- 
2.25.1