Revert "PCI: brcmstb: Add mechanism to turn on subdev regulators"

This reverts commit 67211aad.

This is part of a revert of the following commits:

  11ed8b86 ("PCI: brcmstb: Do not turn off WOL regulators on suspend")
  93e41f3f ("PCI: brcmstb: Add control of subdevice voltage regulators")
  67211aad ("PCI: brcmstb: Add mechanism to turn on subdev regulators")
  830aa6f2 ("PCI: brcmstb: Split brcm_pcie_setup() into two funcs")

Cyril reported that 830aa6f2 ("PCI: brcmstb: Split brcm_pcie_setup()
into two funcs"), which appeared in v5.17-rc1, broke booting on the
Raspberry Pi Compute Module 4.  Apparently 830aa6f2 panics with an
Asynchronous SError Interrupt, and after further commits here is a black
screen on HDMI and no output on the serial console.

This does not seem to affect the Raspberry Pi 4 B.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215925
Link: https://lore.kernel.org/r/20220511201856.808690-4-helgaas@kernel.orgReported-by: Cyril Brulebois <kibi@debian.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/controller/pcie-brcmstb.c

@@ -24,7 +24,6 @@
 #include <linux/pci.h>
 #include <linux/pci-ecam.h>
 #include <linux/printk.h>
-#include <linux/regulator/consumer.h>
 #include <linux/reset.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
@@ -284,14 +283,6 @@ static const struct pcie_cfg_data bcm2711_cfg = {
 	.bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_generic,
 };
 
-struct subdev_regulators {
-	unsigned int num_supplies;
-	struct regulator_bulk_data supplies[];
-};
-
-static int pci_subdev_regulators_add_bus(struct pci_bus *bus);
-static void pci_subdev_regulators_remove_bus(struct pci_bus *bus);
-
 struct brcm_msi {
 	struct device		*dev;
 	void __iomem		*base;
@@ -445,71 +436,6 @@ static int brcm_pcie_set_ssc(struct brcm_pcie *pcie)
 	return ssc && pll ? 0 : -EIO;
 }
 
-static void *alloc_subdev_regulators(struct device *dev)
-{
-	static const char * const supplies[] = {
-		"vpcie3v3",
-		"vpcie3v3aux",
-		"vpcie12v",
-	};
-	const size_t size = sizeof(struct subdev_regulators)
-		+ sizeof(struct regulator_bulk_data) * ARRAY_SIZE(supplies);
-	struct subdev_regulators *sr;
-	int i;
-
-	sr = devm_kzalloc(dev, size, GFP_KERNEL);
-	if (sr) {
-		sr->num_supplies = ARRAY_SIZE(supplies);
-		for (i = 0; i < ARRAY_SIZE(supplies); i++)
-			sr->supplies[i].supply = supplies[i];
-	}
-
-	return sr;
-}
-
-static int pci_subdev_regulators_add_bus(struct pci_bus *bus)
-{
-	struct device *dev = &bus->dev;
-	struct subdev_regulators *sr;
-	int ret;
-
-	if (!dev->of_node || !bus->parent || !pci_is_root_bus(bus->parent))
-		return 0;
-
-	if (dev->driver_data)
-		dev_err(dev, "dev.driver_data unexpectedly non-NULL\n");
-
-	sr = alloc_subdev_regulators(dev);
-	if (!sr)
-		return -ENOMEM;
-
-	dev->driver_data = sr;
-	ret = regulator_bulk_get(dev, sr->num_supplies, sr->supplies);
-	if (ret)
-		return ret;
-
-	ret = regulator_bulk_enable(sr->num_supplies, sr->supplies);
-	if (ret) {
-		dev_err(dev, "failed to enable regulators for downstream device\n");
-		return ret;
-	}
-
-	return 0;
-}
-
-static void pci_subdev_regulators_remove_bus(struct pci_bus *bus)
-{
-	struct device *dev = &bus->dev;
-	struct subdev_regulators *sr = dev->driver_data;
-
-	if (!sr || !bus->parent || !pci_is_root_bus(bus->parent))
-		return;
-
-	if (regulator_bulk_disable(sr->num_supplies, sr->supplies))
-		dev_err(dev, "failed to disable regulators for downstream device\n");
-	dev->driver_data = NULL;
-}
-
 /* Limits operation to a specific generation (1, 2, or 3) */
 static void brcm_pcie_set_gen(struct brcm_pcie *pcie, int gen)
 {
@@ -853,8 +779,6 @@ static struct pci_ops brcm_pcie_ops = {
 	.map_bus = brcm_pcie_map_conf,
 	.read = pci_generic_config_read,
 	.write = pci_generic_config_write,
-	.add_bus = pci_subdev_regulators_add_bus,
-	.remove_bus = pci_subdev_regulators_remove_bus,
 };
 
 static struct pci_ops brcm_pcie_ops32 = {