Fixed MTP to work with TWRP

drivers/soc/qcom/Kconfig

@@ -0,0 +1,11 @@
+#
+# QCOM Soc drivers
+#
+config QCOM_GSBI
+        tristate "QCOM General Serial Bus Interface"
+        depends on ARCH_QCOM
+        help
+          Say y here to enable GSBI support.  The GSBI provides control
+          functions for connecting the underlying serial UART, SPI, and I2C
+          devices to the output pins.
+

drivers/soc/qcom/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o

drivers/soc/qcom/qcom_gsbi.c

@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2014, The Linux foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License rev 2 and
+ * only rev 2 as published by the free Software foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or fITNESS fOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#define GSBI_CTRL_REG		0x0000
+#define GSBI_PROTOCOL_SHIFT	4
+
+struct gsbi_info {
+	struct clk *hclk;
+	u32 mode;
+	u32 crci;
+};
+
+static int gsbi_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct resource *res;
+	void __iomem *base;
+	struct gsbi_info *gsbi;
+
+	gsbi = devm_kzalloc(&pdev->dev, sizeof(*gsbi), GFP_KERNEL);
+
+	if (!gsbi)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	if (of_property_read_u32(node, "qcom,mode", &gsbi->mode)) {
+		dev_err(&pdev->dev, "missing mode configuration\n");
+		return -EINVAL;
+	}
+
+	/* not required, so default to 0 if not present */
+	of_property_read_u32(node, "qcom,crci", &gsbi->crci);
+
+	dev_info(&pdev->dev, "GSBI port protocol: %d crci: %d\n",
+		 gsbi->mode, gsbi->crci);
+	gsbi->hclk = devm_clk_get(&pdev->dev, "iface");
+	if (IS_ERR(gsbi->hclk))
+		return PTR_ERR(gsbi->hclk);
+
+	clk_prepare_enable(gsbi->hclk);
+
+	writel_relaxed((gsbi->mode << GSBI_PROTOCOL_SHIFT) | gsbi->crci,
+				base + GSBI_CTRL_REG);
+
+	/* make sure the gsbi control write is not reordered */
+	wmb();
+
+	platform_set_drvdata(pdev, gsbi);
+
+	return of_platform_populate(node, NULL, NULL, &pdev->dev);
+}
+
+static int gsbi_remove(struct platform_device *pdev)
+{
+	struct gsbi_info *gsbi = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(gsbi->hclk);
+
+	return 0;
+}
+
+static const struct of_device_id gsbi_dt_match[] = {
+	{ .compatible = "qcom,gsbi-v1.0.0", },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, gsbi_dt_match);
+
+static struct platform_driver gsbi_driver = {
+	.driver = {
+		.name		= "gsbi",
+		.owner		= THIS_MODULE,
+		.of_match_table	= gsbi_dt_match,
+	},
+	.probe = gsbi_probe,
+	.remove	= gsbi_remove,
+};
+
+module_platform_driver(gsbi_driver);
+
+MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
+MODULE_DESCRIPTION("QCOM GSBI driver");
+MODULE_LICENSE("GPL v2");