[PATCH v2 1/2] PCI: brcmstb: Add regulator support

[Jaedon Shin <jaedon.shin@xxxxxxxxx>]

ARM-based Broadcom STB SoCs have GPIO-based voltage regulator for PCIe
turning off/on power supplies.

Signed-off-by: Jaedon Shin <jaedon.shin@xxxxxxxxx>
---
 .../bindings/pci/brcm,stb-pcie.yaml           |  3 ++
 drivers/pci/controller/pcie-brcmstb.c         | 36 +++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
index 77d3e81a437b..efa5c885724b 100644
--- a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
+++ b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
@@ -56,6 +56,9 @@ properties:
     description: Indicates usage of spread-spectrum clocking.
     type: boolean
 
+  supply-names:
+    description: List of regulator supplies to use for PCIe
+
 required:
   - reg
   - dma-ranges
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index d20aabc26273..8968ef7fa55d 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -23,6 +23,7 @@
 #include <linux/of_platform.h>
 #include <linux/pci.h>
 #include <linux/printk.h>
+#include <linux/regulator/consumer.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
 #include <linux/string.h>
@@ -173,6 +174,8 @@ struct brcm_pcie {
 	int			gen;
 	u64			msi_target_addr;
 	struct brcm_msi		*msi;
+	struct regulator_bulk_data *vreg_bulk;
+	int			num_vregs;
 };
 
 /*
@@ -898,6 +901,7 @@ static void __brcm_pcie_remove(struct brcm_pcie *pcie)
 {
 	brcm_msi_remove(pcie);
 	brcm_pcie_turn_off(pcie);
+	regulator_bulk_disable(pcie->num_vregs, pcie->vreg_bulk);
 	clk_disable_unprepare(pcie->clk);
 	clk_put(pcie->clk);
 }
@@ -920,6 +924,8 @@ static int brcm_pcie_probe(struct platform_device *pdev)
 	struct brcm_pcie *pcie;
 	struct pci_bus *child;
 	struct resource *res;
+	struct regulator_bulk_data *bulk;
+	int i;
 	int ret;
 
 	bridge = devm_pci_alloc_host_bridge(&pdev->dev, sizeof(*pcie));
@@ -955,6 +961,36 @@ static int brcm_pcie_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	ret = of_property_count_strings(np, "supply-names");
+	pcie->num_vregs = (ret < 0) ? 0 : ret;
+
+	if (pcie->num_vregs) {
+		bulk = devm_kcalloc(pcie->dev, pcie->num_vregs, sizeof(*bulk),
+				    GFP_KERNEL);
+		if (!bulk) {
+			clk_disable_unprepare(pcie->clk);
+			return -ENOMEM;
+		}
+
+		for (i = 0; i < pcie->num_vregs; i++)
+			of_property_read_string_index(np, "supply-names", i,
+						      &bulk[i].supply);
+
+		ret = devm_regulator_bulk_get(pcie->dev, pcie->num_vregs, bulk);
+		if (ret < 0) {
+			clk_disable_unprepare(pcie->clk);
+			return ret;
+		}
+
+		pcie->vreg_bulk = bulk;
+	}
+
+	ret = regulator_bulk_enable(pcie->num_vregs, pcie->vreg_bulk);
+	if (ret) {
+		clk_disable_unprepare(pcie->clk);
+		return ret;
+	}
+
 	ret = brcm_pcie_setup(pcie);
 	if (ret)
 		goto fail;
-- 
2.21.0