Re: [PATCHv6 0/4] n_gsm serdev support and protocol driver for droid4 modem

From: Pavel Machek
Date: Sun Apr 26 2020 - 16:07:25 EST


Hi!

> > > > Here's v4 set of n_gsm serdev support patches, and the related protocol
> > > > driver for the modem found on Motorola Mapphone phones and tablets
> > > > like droid4.
> > > >
> > > > This series only adds basic character device support for the serdev
> > > > driver. Other serdev consumer drivers for specific devices will be
> > > > posted separately.
> > >
> > > I'm still missing an architectural (design) overview here -- reviewer
> > > time is a scarce resource.
> > >
> > > I also suggested earlier that you include, at least as an RFC, one or
> > > more of your child-device drivers so that we can see how this ends up
> > > being used in the end (including an example devicetree).
> >
> > Note that this is useful on its own: we have ofonod running on the top
> > of this doing calls and SMSes.
>
> Yup.
>
> > Tony: I know you have drivers depending on this somewhere (audio
> > routing and GPS), but I can't find them. It is not droid4-pending-v5.6
> > AFAICT. Do you have a pointer / could you publish them somewhere?
>
> Hmm they should be there in droid4-pending-v5.6 branch [0]:
>
> $ git log --abbrev=12 --pretty=format:"%h (\"%s\")" \
> v5.6..droid4-pending-v5.6 | grep -i -e gsm -e mot -e mdm
> e09590a260a4 ("mfd: motmdm: Fix oops on unload of motorola-mdm")
> f9252f9ff6bd ("mfd: motmdm: Revert bad list change")
> d733dcaf4416 ("mfd: motmdm: Fix issue with receiving data before ddata is set")
> 452d2b5d4c95 ("n_gsm: Build fixes for make randconfig build")
> 6882b27ea92a ("phy: mapphone-mdm6600: Fix write timeouts with shorter GPIO toggle interval")
> 58ff58c4b520 ("mfd: motmdm: Add basic DTMF support")
> e92b6f30e5ae ("ASoC: audio-graph-card: Add audio mixer for motorold mdm6600")
> c2caea5767d5 ("gnss: mot-mdm6600: Add support for Motorola Mapphone MDM6600 modem")
> a5f73b7b06f6 ("mfd: motmdm: Add Motorola TS 27.010 serdev driver for devices like droid4")
> 6c311d5aeb0a ("dt-bindings: mfd: motmdm: Add binding for motorola-mdm")
> cd02274b920e ("tty: n_gsm: Add support for serdev drivers")
> a73a48321c98 ("phy: mapphone-mdm6600: Fix timeouts by adding wake-up handling")

Here's better try at getting gnss to work on top of linux-next... but
still no luck.

diff --git a/drivers/gnss/Kconfig b/drivers/gnss/Kconfig
index 960178dfad47..13b91034e3ea 100644
--- a/drivers/gnss/Kconfig
+++ b/drivers/gnss/Kconfig
@@ -15,7 +15,6 @@ if GNSS

config GNSS_MOTMDM
tristate "Motorola Modem TS 27.010 serdev GNSS receiver support"
- depends on MFD_MOTMDM
---help---
Say Y here if you have a Motorola modem using TS 27.010 line
discipline for GNSS such as a Motorola Mapphone series device
diff --git a/drivers/gnss/motmdm.c b/drivers/gnss/motmdm.c
index 5ec2fa25df6f..426e9da6bb12 100644
--- a/drivers/gnss/motmdm.c
+++ b/drivers/gnss/motmdm.c
@@ -21,6 +21,8 @@

#include <linux/mfd/motorola-mdm.h>

+#define DEBUG
+
#define MOTMDM_GNSS_TIMEOUT 1000
#define MOTMDM_GNSS_RATE 1000

@@ -197,6 +199,8 @@ static int motmdm_gnss_receive_data(struct motmdm_dlci *mot_dlci,
if (len <= MOTMDM_GNSS_MPD_LEN)
return 0;

+ printk("gnss: Have %d bytes of data\n", len);
+
switch (buf[MOTMDM_GNSS_MPD_LEN]) {
case 'N': /* UNNNN~+MPDNMEA=NN, */
msg = buf + MOTMDM_GNSS_NMEA_LEN;
diff --git a/drivers/tty/serdev/protocol/serdev-ngsm-motmdm.c b/drivers/tty/serdev/protocol/serdev-ngsm-motmdm.c
index 97eb349f5f13..15353e228b18 100644
--- a/drivers/tty/serdev/protocol/serdev-ngsm-motmdm.c
+++ b/drivers/tty/serdev/protocol/serdev-ngsm-motmdm.c
@@ -4,6 +4,7 @@
* Copyright (C) 2018 - 2020 Tony Lindgren <tony@xxxxxxxxxxx>
*/

+#define DEBUG
#include <linux/cdev.h>
#include <linux/delay.h>
#include <linux/device.h>
@@ -26,6 +27,8 @@
#include <linux/mfd/core.h>
#include <linux/phy/phy.h>

+#include <linux/mfd/motorola-mdm.h>
+
#include <uapi/linux/gsmmux.h>

#define MOTMDM_C_N2 3 /* TS27.010 default value */
@@ -67,36 +70,6 @@ struct motmdm_response {
unsigned int handled:1;
};

-enum motmdm_dlci_nr {
- MOTMDM_DLCI1 = 1,
- MOTMDM_DLCI2,
- MOTMDM_DLCI3,
- MOTMDM_DLCI4,
- MOTMDM_DLCI5,
- MOTMDM_DLCI6,
- MOTMDM_DLCI7,
- MOTMDM_DLCI8,
- MOTMDM_DLCI9,
- MOTMDM_DLCI10,
- MOTMDM_DLCI11,
- MOTMDM_DLCI12,
- MOTMDM_DLCI13,
- MOTMDM_DLCI14,
- MOTMDM_DLCI15,
-};
-
-struct motmdm_dlci {
- struct gsm_serdev_dlci gsm_dlci;
- struct list_head node;
- wait_queue_head_t read_queue;
- struct kfifo read_fifo;
- int line;
- u16 id;
- struct list_head list;
- void *privdata; /* Do not use, internal data */
- void *drvdata; /* Available for consumer drivers */
-};
-
struct motmdm_cdev {
struct motmdm *ddata;
struct list_head node;
@@ -283,6 +256,10 @@ static int motmdm_dlci_handle_command(struct motmdm_dlci *mot_dlci, int id,
break;
}

+ if (mot_dlci->receive_data) {
+ return (*mot_dlci->receive_data)(mot_dlci, buf, len);
+ }
+
if (!resp || !resp->buf)
return -ENODEV;

@@ -415,7 +392,7 @@ static int motmdm_write(struct device *dev, struct motmdm_dlci *mot_dlci,
* Helper for child device drivers to send a command to a DLCI and wait
* for result with a matching packet ID.
*/
-static int motmdm_send_command(struct device *dev,
+int motmdm_send_command(struct device *dev,
struct motmdm_dlci *mot_dlci,
unsigned long timeout_ms,
const unsigned char *cmd, size_t cmdlen,
@@ -477,7 +454,7 @@ static int motmdm_send_command(struct device *dev,
return err;
}

-static int motmdm_register_dlci(struct device *dev,
+int motmdm_register_dlci(struct device *dev,
struct motmdm_dlci *mot_dlci)
{
struct motmdm *ddata;
@@ -522,7 +499,7 @@ static int motmdm_register_dlci(struct device *dev,
return err;
}

-static void motmdm_unregister_dlci(struct device *dev,
+void motmdm_unregister_dlci(struct device *dev,
struct motmdm_dlci *mot_dlci)
{
struct motmdm *ddata;
diff --git a/include/linux/mfd/motorola-mdm.h b/include/linux/mfd/motorola-mdm.h
new file mode 100644
index 000000000000..70c52304ffff
--- /dev/null
+++ b/include/linux/mfd/motorola-mdm.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+struct gsm_serdev_dlci;
+struct kfifo;
+struct motmdm_response;
+
+enum motmdm_dlci_nr {
+ MOTMDM_DLCI1 = 1,
+ MOTMDM_DLCI2,
+ MOTMDM_DLCI3,
+ MOTMDM_DLCI4,
+ MOTMDM_DLCI5,
+ MOTMDM_DLCI6,
+ MOTMDM_DLCI7,
+ MOTMDM_DLCI8,
+ MOTMDM_DLCI9,
+ MOTMDM_DLCI10,
+ MOTMDM_DLCI11,
+ MOTMDM_DLCI12,
+ MOTMDM_DLCI13,
+ MOTMDM_DLCI14,
+ MOTMDM_DLCI15,
+};
+
+enum motmdm_state {
+ MOTMDM_STATE_IDLE = 0,
+ MOTMDM_STATE_DIAL = 1,
+ MOTMDM_STATE_ANSWERING = 2,
+ MOTMDM_STATE_CONNECTING = 3,
+ MOTMDM_STATE_INCOMING = 4,
+ MOTMDM_STATE_CONNECTED = 5,
+ MOTMDM_STATE_HANGING_UP = 6,
+ MOTMDM_STATE_DISCONNECTED = 7,
+};
+
+struct motmdm_dlci {
+ struct gsm_serdev_dlci gsm_dlci;
+ struct list_head node;
+ wait_queue_head_t read_queue;
+ struct kfifo read_fifo;
+ int line;
+ u16 id;
+ struct list_head list;
+ void *privdata; /* Do not use, internal data */
+ void *drvdata; /* Available for consumer drivers */
+
+ int (*receive_data)(struct motmdm_dlci *mot_dlci,
+ const unsigned char *buf,
+ size_t len);
+};
+
+int motmdm_register_dlci(struct device *dev, struct motmdm_dlci *mot_dlci);
+void motmdm_unregister_dlci(struct device *dev, struct motmdm_dlci *mot_dlci);
+
+extern int motmdm_send_command(struct device *dev,
+ struct motmdm_dlci *mot_dlci,
+ unsigned long timeout_ms,
+ const unsigned char *cmd, size_t cmdlen,
+ unsigned char *rsp, size_t rsplen);
diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index 3635fc0ab2a6..63d8d3e731ff 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -878,7 +878,6 @@ config SND_SOC_MAX9860

config SND_SOC_MOTMDM
tristate "Motorola Modem TS 27.010 Voice Call Codec"
- depends on MFD_MOTMDM
help
Enable support for Motorola TS 27.010 line discipline serdev
voice call codec driver for Motorola Mapphone series of devices

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