Hi!

> > Here's the updated set of these patches fixed up for Johan's and
> > Pavel's earlier comments.
> > 
> > This series does the following:
> > 
> > 1. Adds functions to n_gsm.c for serdev-ngsm.c driver to use
> > 
> > 2. Adds a generic serdev-ngsm.c driver that brings up the TS 27.010
> >    TTY ports configured in devicetree with help of n_gsm.c
> > 
> > 3. Allows the use of standard Linux device drivers for dedicated
> >    TS 27.010 channels for devices like GNSS and ALSA found on some
> >    modems for example
> 
> Unfortunately that does not seem to be the case just yet. Your gnss
> driver is still aware that it's using n_gsm for the transport and calls
> into the "parent" serdev-ngsm driver instead of using the serdev
> interface (e.g. as if this was still and MFD driver).

It took me a while to understand what is wrong and how to fix it, but
I seem to have something now.

You... don't want to look at patch below as it is very very much work
in progress.

Best regards,
								Pavel

diff --git a/arch/arm/boot/dts/motorola-mapphone-common.dtsi b/arch/arm/boot/dts/motorola-mapphone-common.dtsi
index f5e7ec8e1028..ce907aa40a28 100644
--- a/arch/arm/boot/dts/motorola-mapphone-common.dtsi
+++ b/arch/arm/boot/dts/motorola-mapphone-common.dtsi
@@ -761,9 +761,22 @@
 		};
 
 		gnss@4 {
-			compatible = "motorola,mapphone-mdm6600-gnss";
+			compatible = "disabled-old,motorola,mapphone-mdm6600-gnss";
 			reg = <4>;
 		};
+
+		port@1 {
+			compatible = "gsmmux,port";
+			reg = <1>;
+			subdev@1 {
+				 compatible = "motorola,mapphone-mdm6600-gnss";
+			};
+		};
+
+		port@3 {
+			compatible = "disabled,gsmmux,port";
+			reg = <3>;
+		};
 	};
 };
 
diff --git a/drivers/gnss/motmdm.c b/drivers/gnss/motmdm.c
index da1d44bed899..4668754408eb 100644
--- a/drivers/gnss/motmdm.c
+++ b/drivers/gnss/motmdm.c
@@ -3,11 +3,14 @@
  * Motorola Modem TS 27.010 serdev GNSS driver
  *
  * Copyright (C) 2018 - 2020 Tony Lindgren <tony@atomide.com>
+ * Copyright (C) 2020 Pavel Machek <pavel@ucw.cz>
  *
  * Based on drivers/gnss/sirf.c driver example:
  * Copyright (C) 2018 Johan Hovold <johan@kernel.org>
  */
 
+/* FIXME: see serial.c for good example..? */
+
 #include <linux/errno.h>
 #include <linux/gnss.h>
 #include <linux/init.h>
@@ -45,7 +48,7 @@ enum motmdm_gnss_status {
 struct motmdm_gnss_data {
 	struct gnss_device *gdev;
 	struct device *modem;
-	struct gsm_serdev_dlci dlci;
+	struct gsm_serdev_dlci_operations dlci;
 	struct delayed_work restart_work;
 	struct mutex mutex;	/* For modem commands */
 	ktime_t last_update;
@@ -76,6 +79,7 @@ int motmdm_gnss_send_command(struct motmdm_gnss_data *ddata,
 	unsigned char cmd[128];
 	int ret, cmdlen;
 
+#if 0
 	cmdlen = len + 5 + 1;
 	if (cmdlen > 128)
 		return -EINVAL;
@@ -109,6 +113,7 @@ int motmdm_gnss_send_command(struct motmdm_gnss_data *ddata,
 	mutex_unlock(&ddata->mutex);
 
 	return ret;
+#endif
 }
 
 /*
@@ -198,7 +203,7 @@ static int motmdm_gnss_finish(struct gnss_device *gdev)
 	return motmdm_gnss_send_command(ddata, cmd, strlen(cmd));
 }
 
-static int motmdm_gnss_receive_data(struct gsm_serdev_dlci *dlci,
+static int motmdm_gnss_receive_data(struct gsm_serdev_dlci_operations *dlci,
 				    const unsigned char *buf,
 				    size_t len)
 {
@@ -208,6 +213,8 @@ static int motmdm_gnss_receive_data(struct gsm_serdev_dlci *dlci,
 	size_t msglen;
 	int error = 0;
 
+	printk("motmdm_gnss_receive_data\n");
+
 	if (len <= MOTMDM_GNSS_RESP_LEN)
 		return 0;
 
@@ -283,9 +290,10 @@ static int motmdm_gnss_receive_data(struct gsm_serdev_dlci *dlci,
 static int motmdm_gnss_open(struct gnss_device *gdev)
 {
 	struct motmdm_gnss_data *ddata = gnss_get_drvdata(gdev);
-	struct gsm_serdev_dlci *dlci = &ddata->dlci;
+	struct gsm_serdev_dlci_operations *dlci = &ddata->dlci;
 	int error;
 
+#if 0
 	dlci->drvdata = gdev;
 	dlci->receive_buf = motmdm_gnss_receive_data;
 
@@ -299,16 +307,17 @@ static int motmdm_gnss_open(struct gnss_device *gdev)
 
 		return error;
 	}
-
+#endif
 	return 0;
 }
 
 static void motmdm_gnss_close(struct gnss_device *gdev)
 {
 	struct motmdm_gnss_data *ddata = gnss_get_drvdata(gdev);
-	struct gsm_serdev_dlci *dlci = &ddata->dlci;
+	struct gsm_serdev_dlci_operations *dlci = &ddata->dlci;
 	int error;
 
+#if 0
 	dlci->receive_buf = NULL;
 	error = motmdm_gnss_finish(gdev);
 	if (error < 0)
@@ -316,15 +325,18 @@ static void motmdm_gnss_close(struct gnss_device *gdev)
 			 __func__, error);
 
 	serdev_ngsm_unregister_dlci(ddata->modem, dlci);
+#endif
 }
 
 static int motmdm_gnss_write_raw(struct gnss_device *gdev,
 				 const unsigned char *buf,
 				 size_t count)
 {
+#if 0
 	struct motmdm_gnss_data *ddata = gnss_get_drvdata(gdev);
 
 	return serdev_ngsm_write(ddata->modem, &ddata->dlci, buf, count);
+#endif
 }
 
 static const struct gnss_operations motmdm_gnss_ops = {
@@ -333,7 +345,84 @@ static const struct gnss_operations motmdm_gnss_ops = {
 	.write_raw	= motmdm_gnss_write_raw,
 };
 
-static int motmdm_gnss_probe(struct platform_device *pdev)
+static int gnss_serial_receive_buf(struct serdev_device *serdev,
+                                        const unsigned char *buf, size_t count)
+{
+	printk("gnss_serial_recieve: %d bytes\n", count);
+	printk("gnss_serial_recieve: have data: %s bytes\n", buf);
+#if 0
+        struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
+	struct gnss_device *gdev = gserial->gdev;
+
+	return gnss_insert_raw(gdev, buf, count);
+#endif
+}
+
+static const struct serdev_device_ops gnss_serial_serdev_ops = {
+        .receive_buf    = gnss_serial_receive_buf,
+        .write_wakeup   = serdev_device_write_wakeup,
+};
+
+
+int motmdm_gnss_test(struct serdev_device *serdev)
+{
+	int ret;
+	if (!serdev)
+		return -EIO;
+	printk("have serdev_device: %p, nr %d\n", serdev, serdev->nr);
+
+	dev_info(&serdev->dev, "interesting line\n");
+	
+	/* HERE */
+	serdev_device_set_drvdata(serdev, NULL);
+        serdev_device_set_client_ops(serdev, &gnss_serial_serdev_ops);
+
+	dev_info(&serdev->dev, "opening serdev\n");
+	ret = serdev_device_open(serdev);
+        if (ret) {
+                return ret;
+	}
+
+//        serdev_device_set_baudrate(serdev, gserial->speed);
+//        serdev_device_set_flow_control(serdev, false);
+	dev_info(&serdev->dev, "writing\n");
+	
+	{
+		int count = 5;
+	ret = serdev_device_write(serdev, "HELLO", count, MAX_SCHEDULE_TIMEOUT);
+        if (ret < 0 || ret < count)
+                return ret;
+
+	}
+	dev_info(&serdev->dev, "waiting\n");
+	
+        serdev_device_wait_until_sent(serdev, 0);
+	dev_info(&serdev->dev, "all ok\n");
+	
+	return 0;
+}
+
+int motmdm_gnss_attach(struct device *dev, int line)
+{
+	int ret;
+	void *me = NULL; /* FIXME */
+        struct serdev_controller *ctrl = to_serdev_controller(dev);
+	struct serdev_device *serdev = ctrl->serdev;
+
+	dev_info(dev, "motmdm_gnss_attach: %d\n", line);
+	if (line != 1)
+		return 0;
+	
+	printk("have serdev_controller: %p == %p, nr %d\n", ctrl, dev, ctrl->nr);
+	printk("have serdev_device: %p %p\n", serdev, dev);
+
+	return motmdm_gnss_test(serdev);
+}
+
+
+EXPORT_SYMBOL(motmdm_gnss_attach);
+
+static int motmdm_gnss_probe(struct serdev_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct motmdm_gnss_data *ddata;
@@ -341,14 +430,22 @@ static int motmdm_gnss_probe(struct platform_device *pdev)
 	u32 line;
 	int ret;
 
+	printk("gnss_probe\n");
+
 	ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
 	if (!ddata)
 		return -ENOMEM;
 
+	printk("gnss_probe: searching for reg\n");
+	motmdm_gnss_test(pdev);
+
+#if 0      
 	ret = of_property_read_u32(dev->of_node, "reg", &line);
 	if (ret)
 		return ret;
 
+	printk("gnss_probe: should not go here\n");
+
 	if (!line)
 		return -EINVAL;
 
@@ -384,16 +481,17 @@ static int motmdm_gnss_probe(struct platform_device *pdev)
 	gnss_put_device(ddata->gdev);
 
 	return ret;
+#endif
 }
 
-static int motmdm_gnss_remove(struct platform_device *pdev)
+static void motmdm_gnss_remove(struct serdev_device *pdev)
 {
+#if 0
 	struct motmdm_gnss_data *data = platform_get_drvdata(pdev);
 
 	gnss_deregister_device(data->gdev);
 	gnss_put_device(data->gdev);
-
-	return 0;
+#endif
 };
 
 #ifdef CONFIG_OF
@@ -404,7 +502,7 @@ static const struct of_device_id motmdm_gnss_of_match[] = {
 MODULE_DEVICE_TABLE(of, motmdm_gnss_of_match);
 #endif
 
-static struct platform_driver motmdm_gnss_driver = {
+static struct serdev_device_driver motmdm_gnss_driver = {
 	.driver	= {
 		.name		= "gnss-mot-mdm6600",
 		.of_match_table	= of_match_ptr(motmdm_gnss_of_match),
@@ -412,7 +510,7 @@ static struct platform_driver motmdm_gnss_driver = {
 	.probe	= motmdm_gnss_probe,
 	.remove	= motmdm_gnss_remove,
 };
-module_platform_driver(motmdm_gnss_driver);
+module_serdev_device_driver(motmdm_gnss_driver);
 
 MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
 MODULE_DESCRIPTION("Motorola Mapphone MDM6600 GNSS receiver driver");
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 460123447fa1..e4d18d38fc42 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -52,14 +52,17 @@
 #include <linux/etherdevice.h>
 #include <linux/gsmmux.h>
 #include <linux/serdev-gsm.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 static int debug;
 module_param(debug, int, 0600);
 
 /* Defaults: these are from the specification */
 
-#define T1	10		/* 100mS */
-#define T2	34		/* 333mS */
+#define T1	10		/* 100ms */
+#define T2	34		/* 333ms */
 #define N2	3		/* Retry 3 times */
 
 /* Use long timers for testing at low speed with debug on */
@@ -152,7 +155,7 @@ struct gsm_dlci {
 	/* Data handling callback */
 	void (*data)(struct gsm_dlci *dlci, const u8 *data, int len);
 	void (*prev_data)(struct gsm_dlci *dlci, const u8 *data, int len);
-	struct gsm_serdev_dlci *ops; /* serdev dlci ops, if used */
+	struct gsm_serdev_dlci_operations *ops; /* serdev dlci ops, if used */
 	struct net_device *net; /* network interface, if created */
 };
 
@@ -1019,7 +1022,7 @@ static void gsm_control_reply(struct gsm_mux *gsm, int cmd, const u8 *data,
 static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci,
 							u32 modem, int clen)
 {
-	int  mlines = 0;
+	int mlines = 0;
 	u8 brk = 0;
 	int fc;
 
@@ -2344,38 +2347,10 @@ static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c)
 }
 
 #ifdef CONFIG_SERIAL_DEV_BUS
-
-/**
- * gsm_serdev_get_config - read ts 27.010 config
- * @gsd:	serdev-gsm instance
- * @c:		ts 27.010 config data
- *
- * See gsm_copy_config_values() for more information.
- */
-int gsm_serdev_get_config(struct gsm_serdev *gsd, struct gsm_config *c)
-{
-	struct gsm_mux *gsm;
-
-	if (!gsd || !gsd->gsm)
-		return -ENODEV;
-
-	gsm = gsd->gsm;
-
-	if (!c)
-		return -EINVAL;
-
-	gsm_copy_config_values(gsm, c);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(gsm_serdev_get_config);
-
 /**
  * gsm_serdev_set_config - set ts 27.010 config
  * @gsd:	serdev-gsm instance
  * @c:		ts 27.010 config data
- *
- * See gsm_config() for more information.
  */
 int gsm_serdev_set_config(struct gsm_serdev *gsd, struct gsm_config *c)
 {
@@ -2404,7 +2379,7 @@ static struct gsm_dlci *gsd_dlci_get(struct gsm_serdev *gsd, int line,
 
 	gsm = gsd->gsm;
 
-	if (line < 1 || line >= 63)
+	if (line < 1 || line >= 62)
 		return ERR_PTR(-EINVAL);
 
 	mutex_lock(&gsm->mutex);
@@ -2431,7 +2406,7 @@ static struct gsm_dlci *gsd_dlci_get(struct gsm_serdev *gsd, int line,
 	return dlci;
 }
 
-static int gsd_dlci_receive_buf(struct gsm_serdev_dlci *ops,
+static int gsd_dlci_receive_buf(struct gsm_serdev_dlci_operations *ops,
 				const unsigned char *buf,
 				size_t len)
 {
@@ -2471,6 +2446,7 @@ static void gsd_dlci_data(struct gsm_dlci *dlci, const u8 *buf, int len)
 	}
 }
 
+/* FIXME: we should not be doing this; serdev_controller_ops->write_buf should be enough? */
 /**
  * gsm_serdev_write - write data to a ts 27.010 channel
  * @gsd:	serdev-gsm instance
@@ -2478,7 +2454,7 @@ static void gsd_dlci_data(struct gsm_dlci *dlci, const u8 *buf, int len)
  * @buf:	write buffer
  * @len:	buffer length
  */
-int gsm_serdev_write(struct gsm_serdev *gsd, struct gsm_serdev_dlci *ops,
+int gsm_serdev_write(struct gsm_serdev *gsd, struct gsm_serdev_dlci_operations *ops,
 		     const u8 *buf, int len)
 {
 	struct gsm_mux *gsm;
@@ -2551,7 +2527,7 @@ EXPORT_SYMBOL_GPL(gsm_serdev_data_kick);
  * @ops:	channel ops
  */
 int gsm_serdev_register_dlci(struct gsm_serdev *gsd,
-			     struct gsm_serdev_dlci *ops)
+			     struct gsm_serdev_dlci_operations *ops)
 {
 	struct gsm_dlci *dlci;
 	struct gsm_mux *gsm;
@@ -2609,7 +2585,7 @@ EXPORT_SYMBOL_GPL(gsm_serdev_register_dlci);
  * @ops:	channel ops
  */
 void gsm_serdev_unregister_dlci(struct gsm_serdev *gsd,
-				struct gsm_serdev_dlci *ops)
+				struct gsm_serdev_dlci_operations *ops)
 {
 	struct gsm_mux *gsm;
 	struct gsm_dlci *dlci;
@@ -2681,12 +2657,16 @@ static struct serdev_device_ops gsd_client_ops = {
 	.write_wakeup = gsd_write_wakeup,
 };
 
+extern int motmdm_gnss_attach(struct device *dev, int line);
+
 int gsm_serdev_register_tty_port(struct gsm_serdev *gsd, int line)
 {
-	struct gsm_serdev_dlci *ops;
+	struct gsm_serdev_dlci_operations *ops;
 	unsigned int base;
 	int error;
-
+	struct device *dev;
+	struct device_node *node;
+		
 	if (line < 1)
 		return -EINVAL;
 
@@ -2704,8 +2684,83 @@ int gsm_serdev_register_tty_port(struct gsm_serdev *gsd, int line)
 		return error;
 	}
 
+
 	base = mux_num_to_base(gsd->gsm);
-	tty_register_device(gsm_tty_driver, base + ops->line, NULL);
+	printk("register_tty_port: have port: %p, %d+%d\n", &gsd->gsm->dlci[line]->port, base, ops->line);
+	dev = &gsd->serdev->dev;
+	if (line != 1)
+		return 0;
+
+	for_each_available_child_of_node(dev->of_node, node) {
+		struct platform_device_info devinfo = {};
+		static int idx;
+		struct platform_device *pdev;
+		const char *c = of_get_property(node, "compatible", NULL);
+		
+		dev_info(dev, "register_tty: child -- %pOF\n", node);
+
+		if (!c)
+			continue;
+		dev_info(dev, "register_tty: child -- %pOF -- compatible %s\n", node, c);
+		if (strcmp(c, "gsmmux,port"))
+			continue;
+
+		printk("n_gsm: Have subnode with right compatible!\n");
+		
+		devinfo.name = kasprintf(GFP_KERNEL, "gsm-mux-%d", idx++);
+		devinfo.parent = dev;
+
+		/* Thanks to core.c: serdev_device_add */
+		pdev = platform_device_register_full(&devinfo);
+		pdev->dev.of_node = node;
+
+#if 0
+		tty_register_device(gsm_tty_driver, base + ops->line, NULL);
+#else
+		{
+			struct device *dev;
+
+			dev = tty_port_register_device_serdev(&gsd->gsm->dlci[line]->port, gsm_tty_driver, base + ops->line, &pdev->dev /* FIXME: needs non-null to attempt serdev registration */ );
+			printk("register_tty_port: got %p\n", dev);
+			{
+#if 0
+				struct serdev_controller *ctrl = to_serdev_controller(dev);
+				struct serdev_device *serdev = serdev_device_alloc(ctrl);
+				int err;
+				if (!serdev)
+					dev_err(dev, "could not alloc serdev, that is bad\n");
+
+				//serdev->dev.of_node = node;
+
+				err = serdev_device_add(serdev);
+				if (err) {
+					dev_err(&serdev->dev,
+						"failure adding device. status %pe\n",
+						ERR_PTR(err));
+					//serdev_device_put(serdev);
+				}
+#endif
+#if 0
+				printk("register_tty_port: Forcing attach\n");
+				/* FIXME: Need to do of_serdev_register_devices() ? */
+				motmdm_gnss_attach(dev, ops->line);
+#endif
+			}
+
+		}
+	}
+#endif
+	/* FIXME:
+
+extern struct device *tty_register_device(struct tty_driver *driver,
+                                          unsigned index, struct device *dev);
+
+Would like tty_port_register_device_attr or better
+	   	       tty_port_register_device_attr_serdev 
+
+ale chce navic struct tty_port *.
+
+		       _attr() -- last 2 arguments can be NULL. */
 
 	return 0;
 }
@@ -2730,7 +2785,7 @@ void gsm_serdev_unregister_tty_port(struct gsm_serdev *gsd, int line)
 }
 EXPORT_SYMBOL_GPL(gsm_serdev_unregister_tty_port);
 
-struct gsm_serdev_dlci *
+struct gsm_serdev_dlci_operations *
 gsm_serdev_tty_port_get_dlci(struct gsm_serdev *gsd, int line)
 {
 	struct gsm_dlci *dlci;
@@ -3644,7 +3699,7 @@ static int gsmtty_break_ctl(struct tty_struct *tty, int state)
 				    properly */
 		encode = 0x0F;
 	else if (state > 0) {
-		encode = state / 200;	/* mS to encoding */
+		encode = state / 200;	/* ms to encoding */
 		if (encode > 0x0F)
 			encode = 0x0F;	/* Best effort */
 	}
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index c5f0d936b003..081702d5479d 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -121,7 +121,7 @@ int serdev_device_add(struct serdev_device *serdev)
 		goto err_clear_serdev;
 	}
 
-	dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
+	dev_info(&serdev->dev, "device %s registered, %p controller %p\n", dev_name(&serdev->dev), serdev, ctrl);
 
 	return 0;
 
@@ -509,7 +509,15 @@ struct serdev_controller *serdev_controller_alloc(struct device *parent,
 	pm_runtime_no_callbacks(&ctrl->dev);
 	pm_suspend_ignore_children(&ctrl->dev, true);
 
-	dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
+	/* /sys/bus/serial/drivers/serdev_ngsm/serial0-0 ?
+
+4806a000.serial:modem:audio-codec@2  modalias  subsystem
+4806a000.serial:modem:gnss@4	     of_node   supplier:phy-usb-phy@1.1
+driver				     power     uevent
+
+	*/
+	dev_info(&ctrl->dev, "allocated controller 0x%p 0x%p id %d [%d]\n",
+		 ctrl, &ctrl->dev, id, ctrl->nr);
 	return ctrl;
 
 err_free:
@@ -527,10 +535,12 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl)
 	bool found = false;
 
 	for_each_available_child_of_node(ctrl->dev.of_node, node) {
+		dev_info(&ctrl->dev, "of_serdev_register_device: considering %pOF\n", node);
+		
 		if (!of_get_property(node, "compatible", NULL))
 			continue;
 
-		dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
+		dev_info(&ctrl->dev, "adding child %pOF\n", node);
 
 		serdev = serdev_device_alloc(ctrl);
 		if (!serdev)
@@ -740,26 +750,34 @@ int serdev_controller_add(struct serdev_controller *ctrl)
 {
 	int ret_of, ret_acpi, ret;
 
+	printk("serdev_controller_add...\n");
+
 	/* Can't register until after driver model init */
 	if (WARN_ON(!is_registered))
 		return -EAGAIN;
 
+	printk("serdev_controller_add 1... %pOF\n", ctrl->dev.of_node);
+	
 	ret = device_add(&ctrl->dev);
 	if (ret)
 		return ret;
 
+	printk("serdev_controller_add 2...\n");	
 	pm_runtime_enable(&ctrl->dev);
 
 	ret_of = of_serdev_register_devices(ctrl);
 	ret_acpi = acpi_serdev_register_devices(ctrl);
 	if (ret_of && ret_acpi) {
-		dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n",
+		dev_info(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n",
 			ERR_PTR(ret_of), ERR_PTR(ret_acpi));
+#if 0
 		ret = -ENODEV;
 		goto err_rpm_disable;
+#endif		
 	}
 
-	dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
+	printk("serdev_controller_add all ok?...\n");		
+	dev_info(&ctrl->dev, "serdev%d registered: dev:%p\n",
 		ctrl->nr, &ctrl->dev);
 	return 0;
 
diff --git a/drivers/tty/serdev/serdev-ngsm.c b/drivers/tty/serdev/serdev-ngsm.c
index a247cf36df4f..a250a3594f71 100644
--- a/drivers/tty/serdev/serdev-ngsm.c
+++ b/drivers/tty/serdev/serdev-ngsm.c
@@ -40,7 +40,7 @@ struct serdev_ngsm {
 	const struct serdev_ngsm_cfg *cfg;
 };
 
-static int serdev_ngsm_tty_init(struct serdev_ngsm *ddata)
+static int serdev_ngsm_tty_init(struct serdev_ngsm *ddata, void *node /* will need of node here ? */)
 {
 	struct gsm_serdev *gsd = &ddata->gsd;
 	struct device *dev = ddata->dev;
@@ -50,7 +50,7 @@ static int serdev_ngsm_tty_init(struct serdev_ngsm *ddata)
 		if (BIT_ULL(bit) & TS27010_RESERVED_DLCI)
 			continue;
 
-		err = gsm_serdev_register_tty_port(gsd, bit);
+		err = gsm_serdev_register_tty_port(gsd, bit /*, node FIXME */);
 		if (err) {
 			dev_err(dev, "ngsm tty init failed for dlci%i: %i\n",
 				bit, err);
@@ -80,7 +80,7 @@ static void serdev_ngsm_tty_exit(struct serdev_ngsm *ddata)
  * drivers may have already reserved.
  */
 int serdev_ngsm_register_dlci(struct device *dev,
-			      struct gsm_serdev_dlci *dlci)
+			      struct gsm_serdev_dlci_operations *dlci)
 {
 	struct serdev_ngsm *ddata = gsm_serdev_get_drvdata(dev);
 	struct gsm_serdev *gsd = &ddata->gsd;
@@ -95,7 +95,7 @@ int serdev_ngsm_register_dlci(struct device *dev,
 EXPORT_SYMBOL_GPL(serdev_ngsm_register_dlci);
 
 void serdev_ngsm_unregister_dlci(struct device *dev,
-				 struct gsm_serdev_dlci *dlci)
+				 struct gsm_serdev_dlci_operations *dlci)
 {
 	struct serdev_ngsm *ddata = gsm_serdev_get_drvdata(dev);
 	struct gsm_serdev *gsd = &ddata->gsd;
@@ -104,7 +104,7 @@ void serdev_ngsm_unregister_dlci(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(serdev_ngsm_unregister_dlci);
 
-int serdev_ngsm_write(struct device *dev, struct gsm_serdev_dlci *ops,
+int serdev_ngsm_write(struct device *dev, struct gsm_serdev_dlci_operations *ops,
 		      const u8 *buf, int len)
 {
 	struct serdev_ngsm *ddata = gsm_serdev_get_drvdata(dev);
@@ -127,7 +127,7 @@ int serdev_ngsm_write(struct device *dev, struct gsm_serdev_dlci *ops,
 }
 EXPORT_SYMBOL_GPL(serdev_ngsm_write);
 
-struct gsm_serdev_dlci *
+struct gsm_serdev_dlci_operations *
 serdev_ngsm_get_dlci(struct device *dev, int line)
 {
 	struct serdev_ngsm *ddata = gsm_serdev_get_drvdata(dev);
@@ -377,7 +377,7 @@ static int serdev_ngsm_probe(struct serdev_device *serdev)
 	if (err)
 		goto err_close;
 
-	err = serdev_ngsm_tty_init(ddata);
+	err = serdev_ngsm_tty_init(ddata, NULL /* FIXME! */);
 	if (err)
 		goto err_tty;
 
diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index d367803e2044..6f02a1546560 100644
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -272,6 +272,8 @@ struct device *serdev_tty_port_register(struct tty_port *port,
 	if (!port || !drv || !parent)
 		return ERR_PTR(-ENODEV);
 
+	printk("serdev_tty_port_register: %p, %d\n", port, idx);
+
 	ctrl = serdev_controller_alloc(parent, sizeof(struct serport));
 	if (!ctrl)
 		return ERR_PTR(-ENOMEM);
@@ -291,9 +293,12 @@ struct device *serdev_tty_port_register(struct tty_port *port,
 		goto err_reset_data;
 
 	dev_info(&ctrl->dev, "tty port %s%d registered\n", drv->name, idx);
+	printk("serdev_tty_port_register: controller is  %p, serdev %p\n", ctrl, ctrl->serdev);
+	
 	return &ctrl->dev;
 
 err_reset_data:
+	printk("serdev_tty_port_register: error?\n");
 	port->client_data = NULL;
 	port->client_ops = &tty_port_default_client_ops;
 	serdev_controller_put(ctrl);
diff --git a/include/linux/serdev-gsm.h b/include/linux/serdev-gsm.h
index 4fa819a6e366..5bdc8143b7df 100644
--- a/include/linux/serdev-gsm.h
+++ b/include/linux/serdev-gsm.h
@@ -7,7 +7,7 @@
 #include <linux/serdev.h>
 #include <linux/types.h>
 
-struct gsm_serdev_dlci;
+struct gsm_serdev_dlci_operations;
 struct gsm_config;
 
 /**
@@ -28,16 +28,16 @@ struct gsm_serdev {
 };
 
 /**
- * struct gsm_serdev_dlci - serdev-gsm ts 27.010 channel data
+ * struct gsm_serdev_dlci_operations - serdev-gsm ts 27.010 channel data
  * @gsd:		serdev-gsm instance
  * @line:		ts 27.010 channel, control channel 0 is not available
  * @receive_buf:	function to handle data received for the channel
  * @drvdata:		dlci specific consumer driver data
  */
-struct gsm_serdev_dlci {
+struct gsm_serdev_dlci_operations {
 	struct gsm_serdev *gsd;
 	int line;
-	int (*receive_buf)(struct gsm_serdev_dlci *ops,
+	int (*receive_buf)(struct gsm_serdev_dlci_operations *ops,
 			   const unsigned char *buf,
 			   size_t len);
 	void *drvdata;
@@ -48,12 +48,12 @@ struct gsm_serdev_dlci {
 /* TS 27.010 channel specific functions for consumer drivers */
 #if IS_ENABLED(CONFIG_SERIAL_DEV_N_GSM)
 extern int
-serdev_ngsm_register_dlci(struct device *dev, struct gsm_serdev_dlci *dlci);
+serdev_ngsm_register_dlci(struct device *dev, struct gsm_serdev_dlci_operations *dlci);
 extern void serdev_ngsm_unregister_dlci(struct device *dev,
-					struct gsm_serdev_dlci *dlci);
-extern int serdev_ngsm_write(struct device *dev, struct gsm_serdev_dlci *ops,
+					struct gsm_serdev_dlci_operations *dlci);
+extern int serdev_ngsm_write(struct device *dev, struct gsm_serdev_dlci_operations *ops,
 			     const u8 *buf, int len);
-extern struct gsm_serdev_dlci *
+extern struct gsm_serdev_dlci_operations *
 serdev_ngsm_get_dlci(struct device *dev, int line);
 #endif
 
@@ -62,7 +62,7 @@ extern int gsm_serdev_register_device(struct gsm_serdev *gsd);
 extern void gsm_serdev_unregister_device(struct gsm_serdev *gsd);
 extern int gsm_serdev_register_tty_port(struct gsm_serdev *gsd, int line);
 extern void gsm_serdev_unregister_tty_port(struct gsm_serdev *gsd, int line);
-extern struct gsm_serdev_dlci *
+extern struct gsm_serdev_dlci_operations *
 gsm_serdev_tty_port_get_dlci(struct gsm_serdev *gsd, int line);
 
 static inline void *gsm_serdev_get_drvdata(struct device *dev)
@@ -88,10 +88,10 @@ static inline void gsm_serdev_set_drvdata(struct device *dev, void *drvdata)
 extern int gsm_serdev_get_config(struct gsm_serdev *gsd, struct gsm_config *c);
 extern int gsm_serdev_set_config(struct gsm_serdev *gsd, struct gsm_config *c);
 extern int
-gsm_serdev_register_dlci(struct gsm_serdev *gsd, struct gsm_serdev_dlci *ops);
+gsm_serdev_register_dlci(struct gsm_serdev *gsd, struct gsm_serdev_dlci_operations *ops);
 extern void
-gsm_serdev_unregister_dlci(struct gsm_serdev *gsd, struct gsm_serdev_dlci *ops);
-extern int gsm_serdev_write(struct gsm_serdev *gsd, struct gsm_serdev_dlci *ops,
+gsm_serdev_unregister_dlci(struct gsm_serdev *gsd, struct gsm_serdev_dlci_operations *ops);
+extern int gsm_serdev_write(struct gsm_serdev *gsd, struct gsm_serdev_dlci_operations *ops,
 			    const u8 *buf, int len);
 extern void gsm_serdev_data_kick(struct gsm_serdev *gsd);
 
@@ -118,7 +118,7 @@ void gsm_serdev_unregister_tty_port(struct gsm_serdev *gsd, int line)
 {
 }
 
-static inline struct gsm_serdev_dlci *
+static inline struct gsm_serdev_dlci_operations *
 gsm_serdev_tty_port_get_dlci(struct gsm_serdev *gsd, int line)
 {
 	return NULL;
@@ -148,19 +148,19 @@ int gsm_serdev_set_config(struct gsm_serdev *gsd, struct gsm_config *c)
 
 static inline
 int gsm_serdev_register_dlci(struct gsm_serdev *gsd,
-			     struct gsm_serdev_dlci *ops)
+			     struct gsm_serdev_dlci_operations *ops)
 {
 	return -ENODEV;
 }
 
 static inline
 void gsm_serdev_unregister_dlci(struct gsm_serdev *gsd,
-				struct gsm_serdev_dlci *ops)
+				struct gsm_serdev_dlci_operations *ops)
 {
 }
 
 static inline
-int gsm_serdev_write(struct gsm_serdev *gsd, struct gsm_serdev_dlci *ops,
+int gsm_serdev_write(struct gsm_serdev *gsd, struct gsm_serdev_dlci_operations *ops,
 		     const u8 *buf, int len)
 {
 	return -ENODEV;
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index 9f14f9c12ec4..efdffe34a9b5 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -128,6 +128,7 @@ static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void
  */
 static inline void serdev_device_put(struct serdev_device *serdev)
 {
+	printk("serdev_device_put... %p\n", serdev);
 	if (serdev)
 		put_device(&serdev->dev);
 }
@@ -156,6 +157,8 @@ static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
  */
 static inline void serdev_controller_put(struct serdev_controller *ctrl)
 {
+	printk("serdev_controller_put... %p\n", ctrl);
+	WARN_ON(1);
 	if (ctrl)
 		put_device(&ctrl->dev);
 }
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index afb9521ddf91..530a0146893c 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -802,7 +802,7 @@ static char *ptr_to_id(char *buf, char *end, const void *ptr,
 	 * Print the real pointer value for NULL and error pointers,
 	 * as they are not actual addresses.
 	 */
-	if (IS_ERR_OR_NULL(ptr))
+//	if (IS_ERR_OR_NULL(ptr))
 		return pointer_string(buf, end, ptr, spec);
 
 	/* When debugging early boot use non-cryptographically secure hash. */
diff --git a/sound/soc/codecs/motmdm.c b/sound/soc/codecs/motmdm.c
index 325a860ef665..1528c89d9d57 100644
--- a/sound/soc/codecs/motmdm.c
+++ b/sound/soc/codecs/motmdm.c
@@ -28,7 +28,7 @@ struct motmdm_driver_data {
 	struct snd_soc_component *component;
 	struct snd_soc_dai *master_dai;
 	struct device *modem;
-	struct gsm_serdev_dlci dlci;
+	struct gsm_serdev_dlci_operations dlci;
 	struct regmap *regmap;
 	unsigned char *buf;
 	size_t len;
@@ -38,7 +38,7 @@ struct motmdm_driver_data {
 	struct mutex mutex;	/* for sending commands */
 	wait_queue_head_t read_queue;
 
-	int (*receive_buf_orig)(struct gsm_serdev_dlci *ops,
+	int (*receive_buf_orig)(struct gsm_serdev_dlci_operations *ops,
 				const unsigned char *buf,
 				size_t len);
 	unsigned int dtmf_val;
@@ -121,7 +121,7 @@ static int motmdm_send_command(struct motmdm_driver_data *ddata,
 }
 
 /* Handle U1234+XXXX= style command response */
-static int motmdm_receive_data(struct gsm_serdev_dlci *dlci,
+static int motmdm_receive_data(struct gsm_serdev_dlci_operations *dlci,
 			       const unsigned char *buf,
 			       size_t len)
 {
@@ -569,7 +569,7 @@ static void motmdm_voice_get_state(struct motmdm_driver_data *ddata,
 		motmdm_disable_primary_dai(ddata->component);
 }
 
-static int receive_buf_voice(struct gsm_serdev_dlci *ops,
+static int receive_buf_voice(struct gsm_serdev_dlci_operations *ops,
 			     const unsigned char *buf,
 			     size_t len)
 {
@@ -585,7 +585,7 @@ static int receive_buf_voice(struct gsm_serdev_dlci *ops,
 /* Read the voice status from dlci1 and let user space handle rest */
 static int motmdm_init_voice_dlci(struct motmdm_driver_data *ddata)
 {
-	struct gsm_serdev_dlci *dlci;
+	struct gsm_serdev_dlci_operations *dlci;
 
 	dlci = serdev_ngsm_get_dlci(ddata->modem, MOTMDM_VOICE_DLCI);
 	if (!dlci)
@@ -600,7 +600,7 @@ static int motmdm_init_voice_dlci(struct motmdm_driver_data *ddata)
 
 static void motmdm_free_voice_dlci(struct motmdm_driver_data *ddata)
 {
-	struct gsm_serdev_dlci *dlci;
+	struct gsm_serdev_dlci_operations *dlci;
 
 	dlci = serdev_ngsm_get_dlci(ddata->modem, MOTMDM_VOICE_DLCI);
 	if (!dlci)
@@ -613,7 +613,7 @@ static void motmdm_free_voice_dlci(struct motmdm_driver_data *ddata)
 static int motmdm_soc_probe(struct snd_soc_component *component)
 {
 	struct motmdm_driver_data *ddata;
-	struct gsm_serdev_dlci *dlci;
+	struct gsm_serdev_dlci_operations *dlci;
 	const unsigned char *cmd = "AT+CMUT=0";
 	int error;
 	u32 line;
@@ -690,7 +690,7 @@ static int motmdm_soc_probe(struct snd_soc_component *component)
 static void motmdm_soc_remove(struct snd_soc_component *component)
 {
 	struct motmdm_driver_data *ddata;
-	struct gsm_serdev_dlci *dlci;
+	struct gsm_serdev_dlci_operations *dlci;
 
 	ddata = snd_soc_component_get_drvdata(component);
 	dlci = &ddata->dlci;
diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c
index 97b4f5480a31..31ff426226ef 100644
--- a/sound/soc/generic/audio-graph-card.c
+++ b/sound/soc/generic/audio-graph-card.c
@@ -631,6 +631,8 @@ static int graph_probe(struct platform_device *pdev)
 	struct link_info li;
 	int ret;
 
+	printk("audio-graph: probe starts\n");
+
 	/* Allocate the private data and the DAI link array */
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -648,19 +650,24 @@ static int graph_probe(struct platform_device *pdev)
 	if (!li.link || !li.dais)
 		return -EINVAL;
 
+	printk("audio-graph: 2\n");
+
 	ret = asoc_simple_init_priv(priv, &li);
 	if (ret < 0)
 		return ret;
 
 	priv->pa_gpio = devm_gpiod_get_optional(dev, "pa", GPIOD_OUT_LOW);
 	if (IS_ERR(priv->pa_gpio)) {
+		printk("audio-graph: optional pa failed\n");
 		ret = PTR_ERR(priv->pa_gpio);
 		dev_err(dev, "failed to get amplifier gpio: %d\n", ret);
 		return ret;
 	}
 
+	printk("audio-graph: parsing of\n");	
 	ret = graph_parse_of(priv);
 	if (ret < 0) {
+		printk("audio-graph: parsing of failed: %d\n", ret);	
 		if (ret != -EPROBE_DEFER)
 			dev_err(dev, "parse error %d\n", ret);
 		goto err;
@@ -670,9 +677,13 @@ static int graph_probe(struct platform_device *pdev)
 
 	asoc_simple_debug_info(priv);
 
+		printk("audio-graph: registering card\n");	
+	
+
 	ret = devm_snd_soc_register_card(dev, card);
 	if (ret < 0)
 		goto err;
+		printk("audio-graph: all ok\n");	
 
 	return 0;
 err:


-- 
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