diag: Convert diag bridge as a platform dev

In order to support DT on DIAG, convert diag
bridge driver to platform driver.

Change-Id: I0ddecc06d9b4845d822799f3cff942789d1441c6
Signed-off-by: Sujeev Dias <sdias@codeaurora.org>

Documentation/devicetree/bindings/arm/msm/diag_mhi.txt

@@ -0,0 +1,12 @@
+Qualcomm Technologies, Inc. Diag MHI Driver
+
+Required properties:
+-compatible : should be "qcom,diag-mhi".
+-qcom,mhi : phandle of MHI Device to connect to.
+
+Example:
+	qcom,diag {
+		compatible = "qcom,diag-mhi";
+		qcom,mhi = <&mhi_wlan>;
+	};
+

drivers/char/diag/diagchar.h

@@ -642,6 +642,7 @@ struct diagchar_dev {
 #endif
 	int time_sync_enabled;
 	uint8_t uses_time_api;
+	struct platform_device *pdev;
 };
 
 extern struct diagchar_dev *driver;

drivers/char/diag/diagchar_core.c

@@ -22,6 +22,8 @@
 #include <linux/sched.h>
 #include <linux/ratelimit.h>
 #include <linux/timer.h>
+#include <linux/platform_device.h>
+#include <linux/msm_mhi.h>
 #ifdef CONFIG_DIAG_OVER_USB
 #include <linux/usb/usbdiag.h>
 #endif
@@ -3589,6 +3591,41 @@ static int diagchar_cleanup(void)
 	return 0;
 }
 
+static int diag_mhi_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	if (!mhi_is_device_ready(&pdev->dev, "qcom,mhi"))
+		return -EPROBE_DEFER;
+	driver->pdev = pdev;
+	ret = diag_remote_init();
+	if (ret) {
+		diag_remote_exit();
+		return ret;
+	}
+	ret = diagfwd_bridge_init();
+	if (ret) {
+		diagfwd_bridge_exit();
+		return ret;
+	}
+	pr_debug("diag: mhi device is ready\n");
+	return 0;
+}
+
+static const struct of_device_id diag_mhi_table[] = {
+	{.compatible = "qcom,diag-mhi"},
+	{},
+};
+
+static struct platform_driver diag_mhi_driver = {
+	.probe = diag_mhi_probe,
+	.driver = {
+		.name = "DIAG MHI Platform",
+		.owner = THIS_MODULE,
+		.of_match_table = diag_mhi_table,
+	},
+};
+
 static int __init diagchar_init(void)
 {
 	dev_t dev;
@@ -3676,9 +3713,6 @@ static int __init diagchar_init(void)
 	if (ret)
 		goto fail;
 	ret = diag_masks_init();
-	if (ret)
-		goto fail;
-	ret = diag_remote_init();
 	if (ret)
 		goto fail;
 	ret = diag_mux_init();
@@ -3717,9 +3751,7 @@ static int __init diagchar_init(void)
 		goto fail;
 
 	pr_debug("diagchar initialized now");
-	ret = diagfwd_bridge_init();
-	if (ret)
-		diagfwd_bridge_exit();
+	platform_driver_register(&diag_mhi_driver);
 	return 0;
 
 fail:
@@ -3733,9 +3765,7 @@ fail:
 	diagfwd_cntl_exit();
 	diag_dci_exit();
 	diag_masks_exit();
-	diag_remote_exit();
 	return -1;
-
 }
 
 static void diagchar_exit(void)

drivers/char/diag/diagfwd_mhi.c

@@ -678,7 +678,11 @@ static int diag_mhi_register_ch(int id, struct diag_mhi_ch_t *ch)
 	atomic_set(&(ch->opened), 0);
 	ctxt = SET_CH_CTXT(id, ch->type);
 	ch->client_info.mhi_client_cb = mhi_notifier;
-	return mhi_register_channel(&ch->hdl, NULL);
+	ch->client_info.chan = ch->chan;
+	ch->client_info.dev = &driver->pdev->dev;
+	ch->client_info.node_name = "qcom,mhi";
+	ch->client_info.user_data = (void *)(uintptr_t)ctxt;
+	return mhi_register_channel(&ch->hdl, &ch->client_info);
 }
 
 int diag_mhi_init()