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

From: Pavel Machek
Date: Sun Apr 26 2020 - 03:27:30 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")

Thanks for pointers, I was lost in all the git trees. Port is not
quite trivial :-(.

I tried to port GPS and codec support over to new version of base
patches, but I get oops when I try to open the GPS:

Best regards,
Pavel

[ 182.877014] bfe0: 00000005 bed23af8 b6f279cf b6eb46f6 00070030
bed23ea7 00000000 00000000
[ 182.901672] [<c06e7ba8>] (motmdm_gnss_open) from [<c06e71d4>]
(gnss_open+0x7c/0xb0)
[ 182.901672] [<c06e71d4>] (gnss_open) from [<c0221fe0>]
(chrdev_open+0x9c/0x194)
[ 182.901672] [<c0221fe0>] (chrdev_open) from [<c0219524>]
(do_dentry_open+0x21c/0x3e8)
[ 182.901672] [<c0219524>] (do_dentry_open) from [<c022b424>]
(path_openat+0x8b0/0xc1c)
[ 182.901672] [<c022b424>] (path_openat) from [<c022d0ac>]
(do_filp_open+0x60/0xb4)
[ 182.940002] [<c022d0ac>] (do_filp_open) from [<c0219958>]
(do_sys_openat2+0x1f0/0x2f4)
[ 182.940002] [<c0219958>] (do_sys_openat2) from [<c021ada8>]
(do_sys_open+0x98:

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/tty/serdev/protocol/serdev-ngsm-motmdm.c b/drivers/tty/serdev/protocol/serdev-ngsm-motmdm.c
index 97eb349f5f13..f234a0cd2fb7 100644
--- a/drivers/tty/serdev/protocol/serdev-ngsm-motmdm.c
+++ b/drivers/tty/serdev/protocol/serdev-ngsm-motmdm.c
@@ -477,7 +477,7 @@ 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 +522,7 @@ 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..aae61050cd34
--- /dev/null
+++ b/include/linux/mfd/motorola-mdm.h
@@ -0,0 +1,84 @@
+/* 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;
+ int (*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);
+ int (*handle_command)(struct motmdm_dlci *mot_dlci, int id,
+ const unsigned char *buf, size_t len);
+ int (*receive_data)(struct motmdm_dlci *mot_dlci,
+ const unsigned char *buf,
+ size_t len);
+ int (*write)(struct device *dev, struct motmdm_dlci *mot_dlci,
+ int cmdid, const unsigned char *buf, size_t count);
+ int (*notify)(struct motmdm_dlci *mot_dlci, enum motmdm_state);
+ struct list_head list;
+ void *privdata; /* Do not use, internal data */
+ void *drvdata; /* Available for consumer drivers */
+};
+
+int motmdm_register_dlci(struct device *dev, struct motmdm_dlci *mot_dlci);
+void motmdm_unregister_dlci(struct device *dev, struct motmdm_dlci *mot_dlci);
+
+static inline
+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)
+{
+ if (mot_dlci && mot_dlci->send_command)
+ return mot_dlci->send_command(dev, mot_dlci,
+ timeout_ms, cmd, cmdlen,
+ rsp, rsplen);
+ else
+ return -EINVAL;
+}
+
+static inline
+int motmdm_write(struct device *dev, struct motmdm_dlci *mot_dlci,
+ const unsigned char *buf, size_t count)
+{
+ if (mot_dlci && mot_dlci->write)
+ return mot_dlci->write(dev, mot_dlci, -1, buf, count);
+ else
+ return -EINVAL;
+}
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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HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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