On Tue, Mar 09, 2021 at 09:01:11AM -0700, Jeffrey Hugo wrote: > On 3/9/2021 3:33 AM, Greg KH wrote: > > On Tue, Mar 09, 2021 at 11:28:49AM +0100, Loic Poulain wrote: > > > Hi Greg, > > > > > > On Tue, 9 Mar 2021 at 10:35, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > > > > On Tue, Mar 09, 2021 at 09:42:16AM +0100, Loic Poulain wrote: > > > > > The MHI WWWAN control driver allows MHI Qcom based modems to expose > > > > > different modem control protocols/ports to userspace, so that userspace > > > > > modem tools or daemon (e.g. ModemManager) can control WWAN config > > > > > and state (APN config, SMS, provider selection...). A Qcom based > > > > > modem can expose one or several of the following protocols: > > > > > - AT: Well known AT commands interactive protocol (microcom, minicom...) > > > > > - MBIM: Mobile Broadband Interface Model (libmbim, mbimcli) > > > > > - QMI: Qcom MSM/Modem Interface (libqmi, qmicli) > > > > > - QCDM: Qcom Modem diagnostic interface (libqcdm) > > > > > - FIREHOSE: XML-based protocol for Modem firmware management > > > > > (qmi-firmware-update) > > > > > > > > > > The different interfaces are exposed as character devices, in the same > > > > > way as for USB modem variants (known as modem 'ports'). > > > > > > > > > > Note that this patch is mostly a rework of the earlier MHI UCI > > > > > tentative that was a generic interface for accessing MHI bus from > > > > > userspace. As suggested, this new version is WWAN specific and is > > > > > dedicated to only expose channels used for controlling a modem, and > > > > > for which related opensource user support exist. Other MHI channels > > > > > not fitting the requirements will request either to be plugged to > > > > > the right Linux subsystem (when available) or to be discussed as a > > > > > new MHI driver (e.g AI accelerator, WiFi debug channels, etc...). > > > > > > > > > > This change introduces a new drivers/net/wwan directory, aiming to > > > > > be the common place for WWAN drivers. > > > > > > > > > > Co-developed-by: Hemant Kumar <hemantk@xxxxxxxxxxxxxx> > > > > > Signed-off-by: Hemant Kumar <hemantk@xxxxxxxxxxxxxx> > > > > > Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx> > > > > > --- > > > > > v2: update copyright (2021) > > > > > v3: Move driver to dedicated drivers/net/wwan directory > > > > > > > > > > drivers/net/Kconfig | 2 + > > > > > drivers/net/Makefile | 1 + > > > > > drivers/net/wwan/Kconfig | 26 ++ > > > > > drivers/net/wwan/Makefile | 6 + > > > > > drivers/net/wwan/mhi_wwan_ctrl.c | 559 +++++++++++++++++++++++++++++++++++++++ > > > > > 5 files changed, 594 insertions(+) > > > > > create mode 100644 drivers/net/wwan/Kconfig > > > > > create mode 100644 drivers/net/wwan/Makefile > > > > > create mode 100644 drivers/net/wwan/mhi_wwan_ctrl.c > > > > > > > > > > diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig > > > > > index 1ebb4b9..28b18f2 100644 > > > > > --- a/drivers/net/Kconfig > > > > > +++ b/drivers/net/Kconfig > > > > > @@ -501,6 +501,8 @@ source "drivers/net/wan/Kconfig" > > > > > > > > > > source "drivers/net/ieee802154/Kconfig" > > > > > > > > > > +source "drivers/net/wwan/Kconfig" > > > > > + > > > > > config XEN_NETDEV_FRONTEND > > > > > tristate "Xen network device frontend driver" > > > > > depends on XEN > > > > > diff --git a/drivers/net/Makefile b/drivers/net/Makefile > > > > > index f4990ff..5da6424 100644 > > > > > --- a/drivers/net/Makefile > > > > > +++ b/drivers/net/Makefile > > > > > @@ -68,6 +68,7 @@ obj-$(CONFIG_SUNGEM_PHY) += sungem_phy.o > > > > > obj-$(CONFIG_WAN) += wan/ > > > > > obj-$(CONFIG_WLAN) += wireless/ > > > > > obj-$(CONFIG_IEEE802154) += ieee802154/ > > > > > +obj-$(CONFIG_WWAN) += wwan/ > > > > > > > > > > obj-$(CONFIG_VMXNET3) += vmxnet3/ > > > > > obj-$(CONFIG_XEN_NETDEV_FRONTEND) += xen-netfront.o > > > > > diff --git a/drivers/net/wwan/Kconfig b/drivers/net/wwan/Kconfig > > > > > new file mode 100644 > > > > > index 0000000..643aa10 > > > > > --- /dev/null > > > > > +++ b/drivers/net/wwan/Kconfig > > > > > @@ -0,0 +1,26 @@ > > > > > +# SPDX-License-Identifier: GPL-2.0-only > > > > > +# > > > > > +# Wireless WAN device configuration > > > > > +# > > > > > + > > > > > +menuconfig WWAN > > > > > + bool "Wireless WAN" > > > > > + help > > > > > + This section contains Wireless WAN driver configurations. > > > > > + > > > > > +if WWAN > > > > > + > > > > > +config MHI_WWAN_CTRL > > > > > + tristate "MHI WWAN control driver for QCOM based PCIe modems" > > > > > + depends on MHI_BUS > > > > > + help > > > > > + MHI WWAN CTRL allow QCOM based PCIe modems to expose different modem > > > > > + control protocols/ports to userspace, including AT, MBIM, QMI, DIAG > > > > > + and FIREHOSE. These protocols can be accessed directly from userspace > > > > > + (e.g. AT commands) or via libraries/tools (e.g. libmbim, libqmi, > > > > > + libqcdm...). > > > > > + > > > > > + To compile this driver as a module, choose M here: the module will be > > > > > + called mhi_wwan_ctrl. > > > > > + > > > > > +endif # WWAN > > > > > diff --git a/drivers/net/wwan/Makefile b/drivers/net/wwan/Makefile > > > > > new file mode 100644 > > > > > index 0000000..994a80b > > > > > --- /dev/null > > > > > +++ b/drivers/net/wwan/Makefile > > > > > @@ -0,0 +1,6 @@ > > > > > +# SPDX-License-Identifier: GPL-2.0 > > > > > +# > > > > > +# Makefile for the Linux WWAN device drivers. > > > > > +# > > > > > + > > > > > +obj-$(CONFIG_MHI_WWAN_CTRL) += mhi_wwan_ctrl.o > > > > > diff --git a/drivers/net/wwan/mhi_wwan_ctrl.c b/drivers/net/wwan/mhi_wwan_ctrl.c > > > > > new file mode 100644 > > > > > index 0000000..3904cd0 > > > > > --- /dev/null > > > > > +++ b/drivers/net/wwan/mhi_wwan_ctrl.c > > > > > @@ -0,0 +1,559 @@ > > > > > +// SPDX-License-Identifier: GPL-2.0-only > > > > > +/* Copyright (c) 2018-2021, The Linux Foundation. All rights reserved.*/ > > > > > + > > > > > +#include <linux/kernel.h> > > > > > +#include <linux/mhi.h> > > > > > +#include <linux/mod_devicetable.h> > > > > > +#include <linux/module.h> > > > > > +#include <linux/poll.h> > > > > > + > > > > > +#define MHI_WWAN_CTRL_DRIVER_NAME "mhi_wwan_ctrl" > > > > > > > > So a driver name is the same as the class that is being created? > > > > > > > > That feels wrong, shouldn't the "class" be wwan? > > > > > > The driver does not aim to be THE wwan implementation, given the > > > heterogeneity of WWAN interfaces, so 'wwan' is probably too generic > > > for this bus/vendor specific driver. But since we create a new wwan > > > subdir, maybe we should create a minimal wwan_sysfs.c, that would > > > initially just offer a common class for all WWAN devices (wwan or > > > wwan-ports), as a first step to if not standardize, at least group > > > such devices under the same hat. Otherwise, we can just use the misc > > > class... Any thoughts? > > > > Why isn't this a good api for all wwan devices? Do you think that this > > will not work for others? > > > > A common class would be good, if they all work the same with regards to > > a user/kernel api, otherwise it's pointless and not needed :) > > > > And if we are back to the "custom user/kernel api just for this one > > driver", then yes, the misc api is the easiest and simplest to use, but > > I would wish for better than that for the first wwan driver... > > I'm thinking this doesn't fit with the misc api due to the number of device > minors that could be expected to be consumed. That's why I asked how many minors do you need :) > Each device supported by this driver is going to create 2-5 chardevs. Having > two devices in a system is common for "endusers". Development, > manufacturing, and test (including the community, not just talking Qualcomm > here) commonly have 12+ of these devices in a system. 12 * 5 = 60. Thats a > lot of misc minor numbers to chew up just from one driver given that the > limit of dynamic minors is 128. Looking at a random x86 server that I have > which could be used for such a usecase already has 30 misc minor numbers > used, and this particular server has a fresh distro install on it. I would > expect that number to go up as it gets provisioned for use. Look at a phone these days, I see way more misc devices used than just "30" :( > I guess, the question to you is, how many misc minor numbers is "too much" > for a single driver to expect to consume? If you expect more than 10, I would say to use a real major number. But be explicit as to what you are expecting here, it was not obvious at all. thanks, greg k-h
