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

Signed-off-by: Jaedon Shin <redacted>
---
 drivers/gpio/gpio-brcmstb.c           | 13 ++++-
 drivers/pci/controller/pcie-brcmstb.c | 76 +++++++++++++++++++++++++++
 2 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-brcmstb.c b/drivers/gpio/gpio-brcmstb.c
index 05e3f99ae59c..0cee5fcd2782 100644
--- a/drivers/gpio/gpio-brcmstb.c
+++ b/drivers/gpio/gpio-brcmstb.c

@@ -777,7 +777,18 @@ static struct platform_driver brcmstb_gpio_driver = {
        .remove = brcmstb_gpio_remove,
        .shutdown = brcmstb_gpio_shutdown,
 };
-module_platform_driver(brcmstb_gpio_driver);
+
+static int __init brcmstb_gpio_init(void)
+{
+       return platform_driver_register(&brcmstb_gpio_driver);
+}
+subsys_initcall(brcmstb_gpio_init);
+
+static void __exit brcmstb_gpio_exit(void)
+{
+       platform_driver_unregister(&brcmstb_gpio_driver);
+}
+module_exit(brcmstb_gpio_exit);

 MODULE_AUTHOR("Gregory Fong");
 MODULE_DESCRIPTION("Driver for Broadcom BRCMSTB SoC UPG GPIO");

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 34581a6a7313..0e0ca39a680b 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>

@@ -173,8 +174,79 @@ struct brcm_pcie {
        int                     gen;
        u64                     msi_target_addr;
        struct brcm_msi         *msi;
+#ifdef CONFIG_REGULATOR
+       int                     num_regs;
+       struct regulator        **regs;
+#endif
 };

+#ifdef CONFIG_REGULATOR
+static void brcm_pcie_regulator_enable(struct brcm_pcie *pcie)
+{
+       int i, ret;
+
+       for (i = 0; i < pcie->num_regs; i++) {
+               if (!pcie->regs[i])
+                       continue;
+
+               ret = regulator_enable(pcie->regs[i]);
+               if (ret)
+                       dev_err(pcie->dev, "Failed to enable regulator\n");
+       }
+}
+
+static void brcm_pcie_regulator_disable(struct brcm_pcie *pcie)
+{
+       int i, ret;
+
+       for (i = 0; i < pcie->num_regs; i++) {
+               if (!pcie->regs[i])
+                       continue;
+
+               ret = regulator_disable(pcie->regs[i]);
+               if (ret)
+                       dev_err(pcie->dev, "Failed to disable regulator\n");
+       }
+}
+
+static void brcm_pcie_regulator_init(struct brcm_pcie *pcie)
+{
+       struct device_node *np = pcie->dev->of_node;
+       struct device *dev = pcie->dev;
+       const char *name;
+       struct regulator *reg;
+       int i;
+
+       pcie->num_regs = of_property_count_strings(np, "supply-names");
+       if (pcie->num_regs <= 0) {
+               pcie->num_regs = 0;
+               return;
+       }
+
+       pcie->regs = devm_kcalloc(dev, pcie->num_regs, sizeof(pcie->regs[0]),
+                                 GFP_KERNEL);
+       if (!pcie->regs) {
+               pcie->num_regs = 0;
+               return;
+       }
+
+       for (i = 0; i < pcie->num_regs; i++) {
+               if (of_property_read_string_index(np, "supply-names", i, &name))
+                       continue;
+
+               reg = devm_regulator_get_optional(dev, name);
+               if (IS_ERR(reg))
+                       continue;
+
+               pcie->regs[i] = reg;
+       }
+}
+#else
+static inline void brcm_pcie_regulator_enable(struct brcm_pcie *pcie) { }
+static inline void brcm_pcie_regulator_disable(struct brcm_pcie *pcie) { }
+static inline void brcm_pcie_regulator_init(struct brcm_pcie *pcie) { }
+#endif
+
 /*
  * This is to convert the size of the inbound "BAR" region to the
  * non-linear values of PCIE_X_MISC_RC_BAR[123]_CONFIG_LO.SIZE

@@ -898,6 +970,7 @@ static void __brcm_pcie_remove(struct brcm_pcie *pcie)
 {
        brcm_msi_remove(pcie);
        brcm_pcie_turn_off(pcie);
+       brcm_pcie_regulator_disable(pcie);
        clk_disable_unprepare(pcie->clk);
        clk_put(pcie->clk);
 }

@@ -955,6 +1028,9 @@ static int brcm_pcie_probe(struct platform_device *pdev)
                return ret;
        }

+       brcm_pcie_regulator_init(pcie);
+       brcm_pcie_regulator_enable(pcie);
+
        ret = brcm_pcie_setup(pcie);
        if (ret)
                goto fail;
--

2.21.0