MLK-10188 arm: imx: Add dummy LDO2p5 regulator for VBUS wakeup

LDO2p5 cannot be disabled in low power idle mode when the USB driver
enables VBUS wakeup. To identify when LDO2p5 can be disabled add a dummy
regulator that the USB driver will enable when VBUS wakeup is required.

This patch is copied from commit 7d849e4d9ebca3c as code the structure has
changed too many. directly cherry-pick has too many conflicts to resolve

Signed-off-by: Bai Ping <b51503@freescale.com>
(cherry picked from commit 25a42aeb8eeb0b894a70e1a0f6750ced39830a46)

2 files changed, 84 insertions, 0 deletions

diff --git a/arch/arm/boot/dts/imx6sl.dtsi b/arch/arm/boot/dts/imx6sl.dtsi
index 010293e2211f..53e10ddc6e1c 100644
--- a/arch/arm/boot/dts/imx6sl.dtsi
+++ b/arch/arm/boot/dts/imx6sl.dtsi
@@ -108,6 +108,10 @@
 		};
 	};
 
+	reg_vbus_wakeup: usb_vbus_wakeup {
+		compatible = "fsl,imx6-dummy-ldo2p5";
+	};
+
 	soc {
 		#address-cells = <1>;
 		#size-cells = <1>;
@@ -846,6 +850,7 @@
 				compatible = "fsl,imx6sl-usbmisc", "fsl,imx6q-usbmisc";
 				reg = <0x02184800 0x200>;
 				clocks = <&clks IMX6SL_CLK_USBOH3>;
+				vbus-wakeup-supply = <&reg_vbus_wakeup>;
 			};
 
 			fec: ethernet@02188000 {
diff --git a/arch/arm/mach-imx/cpuidle-imx6sl.c b/arch/arm/mach-imx/cpuidle-imx6sl.c
index 4813d99e2635..21ecebf699aa 100644
--- a/arch/arm/mach-imx/cpuidle-imx6sl.c
+++ b/arch/arm/mach-imx/cpuidle-imx6sl.c
@@ -10,6 +10,9 @@
 #include <linux/cpuidle.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
 #include <asm/cpuidle.h>
 #include <asm/fncpy.h>
 #include <asm/proc-fns.h>
@@ -48,6 +51,13 @@ static const u32 imx6sl_mmdc_io_offset[] __initconst = {
 	0x330, 0x334, 0x320,	    /*SDCKE0, SDCK1, RESET */
 };
 
+static struct regulator *vbus_ldo;
+static struct regulator_dev *ldo2p5_dummy_regulator_rdev;
+static struct regulator_init_data ldo2p5_dummy_initdata = {
+	.constraints = {
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+	},
+};
 static int ldo2p5_dummy_enable;
 
 static void (*imx6sl_wfi_in_iram_fn)(void __iomem *iram_vbase,
@@ -105,6 +115,10 @@ int __init imx6sl_cpuidle_init(void)
 	const u32 *mmdc_offset_array;
 	u32 wfi_code_size;
 
+	vbus_ldo = regulator_get(NULL, "ldo2p5-dummy");
+	if (IS_ERR(vbus_ldo))
+		vbus_ldo = NULL;
+
 	wfi_iram_base = (void *)(iram_tlb_base_addr + MX6_CPUIDLE_IRAM_ADDR_OFFSET);
 
 	/* Make sure wif_iram_base is 8 byte aligned. */
@@ -134,3 +148,68 @@ int __init imx6sl_cpuidle_init(void)
 
 	return cpuidle_register(&imx6sl_cpuidle_driver, NULL);
 }
+
+static int imx_ldo2p5_dummy_enable(struct regulator_dev *rdev)
+{
+	ldo2p5_dummy_enable = 1;
+	return 0;
+}
+
+static int imx_ldo2p5_dummy_disable(struct regulator_dev *rdev)
+{
+	ldo2p5_dummy_enable = 0;
+	return 0;
+}
+
+static int imx_ldo2p5_dummy_is_enable(struct regulator_dev *rdev)
+{
+	return ldo2p5_dummy_enable;
+}
+
+static struct regulator_ops ldo2p5_dummy_ops = {
+	.enable = imx_ldo2p5_dummy_enable,
+	.disable = imx_ldo2p5_dummy_disable,
+	.is_enabled = imx_ldo2p5_dummy_is_enable,
+};
+
+static struct regulator_desc ldo2p5_dummy_desc = {
+	.name = "ldo2p5-dummy",
+	.id = -1,
+	.type = REGULATOR_VOLTAGE,
+	.owner = THIS_MODULE,
+	.ops = &ldo2p5_dummy_ops,
+};
+
+static int ldo2p5_dummy_probe(struct platform_device *pdev)
+{
+	struct regulator_config config = { };
+	int ret;
+
+	config.dev = &pdev->dev;
+	config.init_data = &ldo2p5_dummy_initdata;
+	config.of_node = pdev->dev.of_node;
+
+	ldo2p5_dummy_regulator_rdev = regulator_register(&ldo2p5_dummy_desc, &config);
+	if (IS_ERR(ldo2p5_dummy_regulator_rdev)) {
+		ret = PTR_ERR(ldo2p5_dummy_regulator_rdev);
+		dev_err(&pdev->dev, "Failed to register dummy ldo2p5 regulator: %d\n", ret);
+		return ret;
+	}
+	return 0;
+}
+
+static const struct of_device_id imx_ldo2p5_dummy_ids[] = {
+	{ .compatible = "fsl,imx6-dummy-ldo2p5"},
+	};
+MODULE_DEVICE_TABLE(ofm, imx_ldo2p5_dummy_ids);
+
+static struct platform_driver ldo2p5_dummy_driver = {
+	.probe = ldo2p5_dummy_probe,
+	.driver = {
+		.name = "ldo2p5-dummy",
+		.owner = THIS_MODULE,
+		.of_match_table = imx_ldo2p5_dummy_ids,
+	},
+};
+
+module_platform_driver(ldo2p5_dummy_driver);