| Message ID | 1615237167-19969-1-git-send-email-loic.poulain@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] bus: mhi: Add Qcom WWAN control driver | expand |
On Tue, 9 Mar 2021 at 09:19, Greg KH <gregkh@linuxfoundation.org> wrote: > > On Mon, Mar 08, 2021 at 09:59:27PM +0100, Loic Poulain wrote: > > The MHI WWWAN control driver allows MHI Qcom based modems to expose > > different modem control protocols 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. > > > > 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...). > > > > Co-developed-by: Hemant Kumar <hemantk@codeaurora.org> > > Signed-off-by: Hemant Kumar <hemantk@codeaurora.org> > > Signed-off-by: Loic Poulain <loic.poulain@linaro.org> > > --- > > v2: update copyright (2021) > > > > drivers/bus/mhi/Kconfig | 12 + > > drivers/bus/mhi/Makefile | 3 + > > drivers/bus/mhi/wwan_ctrl.c | 559 ++++++++++++++++++++++++++++++++++++++++++++ > > As Jakub said, why is this file in this directory? > > Flat out ignoring review comments is a sure way to always get pushed to > the bottom of the list of things anyone wants to ever look at... Yes, it's a legacy of the previous driver that was kind of a generic a mhi bus accessor. I'm going to move it inside network since it's about WWAN. Thanks, Loic > > greg k-h
Hi Loic,
I love your patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v5.12-rc3 next-20210319]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Loic-Poulain/bus-mhi-Add-Qcom-WWAN-control-driver/20210309-045313
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 144c79ef33536b4ecb4951e07dbc1f2b7fa99d32
config: x86_64-allyesconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/727df932009e4a00b877f66f9a77658967e0d8a4
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Loic-Poulain/bus-mhi-Add-Qcom-WWAN-control-driver/20210309-045313
git checkout 727df932009e4a00b877f66f9a77658967e0d8a4
# save the attached .config to linux build tree
make W=1 ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
drivers/bus/mhi/wwan_ctrl.c: In function 'mhi_wwan_ctrl_open':
>> drivers/bus/mhi/wwan_ctrl.c:137:9: error: too many arguments to function 'mhi_prepare_for_transfer'
137 | ret = mhi_prepare_for_transfer(wwandev->mhi_dev, 0);
| ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/bus/mhi/wwan_ctrl.c:5:
include/linux/mhi.h:718:5: note: declared here
718 | int mhi_prepare_for_transfer(struct mhi_device *mhi_dev);
| ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from include/linux/kernel.h:14,
from drivers/bus/mhi/wwan_ctrl.c:4:
drivers/bus/mhi/wwan_ctrl.c: In function 'mhi_wwan_ctrl_probe':
drivers/bus/mhi/wwan_ctrl.c:442:48: error: 'MHI_MAX_MTU' undeclared (first use in this function); did you mean 'ETH_MAX_MTU'?
442 | wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
| ^~~~~~~~~~~
include/linux/minmax.h:18:39: note: in definition of macro '__typecheck'
18 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
| ^
include/linux/minmax.h:42:24: note: in expansion of macro '__safe_cmp'
42 | __builtin_choose_expr(__safe_cmp(x, y), \
| ^~~~~~~~~~
include/linux/minmax.h:110:27: note: in expansion of macro '__careful_cmp'
110 | #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
| ^~~~~~~~~~~~~
drivers/bus/mhi/wwan_ctrl.c:442:17: note: in expansion of macro 'min_t'
442 | wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
| ^~~~~
drivers/bus/mhi/wwan_ctrl.c:442:48: note: each undeclared identifier is reported only once for each function it appears in
442 | wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
| ^~~~~~~~~~~
include/linux/minmax.h:18:39: note: in definition of macro '__typecheck'
18 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
| ^
include/linux/minmax.h:42:24: note: in expansion of macro '__safe_cmp'
42 | __builtin_choose_expr(__safe_cmp(x, y), \
| ^~~~~~~~~~
include/linux/minmax.h:110:27: note: in expansion of macro '__careful_cmp'
110 | #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
| ^~~~~~~~~~~~~
drivers/bus/mhi/wwan_ctrl.c:442:17: note: in expansion of macro 'min_t'
442 | wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
| ^~~~~
include/linux/minmax.h:42:2: error: first argument to '__builtin_choose_expr' not a constant
42 | __builtin_choose_expr(__safe_cmp(x, y), \
| ^~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:110:27: note: in expansion of macro '__careful_cmp'
110 | #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
| ^~~~~~~~~~~~~
drivers/bus/mhi/wwan_ctrl.c:442:17: note: in expansion of macro 'min_t'
442 | wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
| ^~~~~
drivers/bus/mhi/wwan_ctrl.c: At top level:
>> drivers/bus/mhi/wwan_ctrl.c:504:53: error: 'MHI_MAX_MTU' undeclared here (not in a function); did you mean 'ETH_MAX_MTU'?
504 | { .chan = MHI_WWAN_CTRL_PROTO_QCDM, .driver_data = MHI_MAX_MTU },
| ^~~~~~~~~~~
| ETH_MAX_MTU
vim +/mhi_prepare_for_transfer +137 drivers/bus/mhi/wwan_ctrl.c
117
118 static int mhi_wwan_ctrl_open(struct inode *inode, struct file *filp)
119 {
120 unsigned int minor = iminor(inode);
121 struct mhi_wwan_dev *wwandev = NULL;
122 int ret = 0;
123
124 /* Retrieve corresponding mhi_wwan_dev and get a reference */
125 mutex_lock(&mhi_wwan_ctrl_drv_lock);
126 wwandev = idr_find(&mhi_wwan_ctrl_idr, minor);
127 if (!wwandev) {
128 mutex_unlock(&mhi_wwan_ctrl_drv_lock);
129 return -ENODEV;
130 }
131 kref_get(&wwandev->ref_count);
132 mutex_unlock(&mhi_wwan_ctrl_drv_lock);
133
134 /* Start MHI channel(s) if not yet started and fill RX queue */
135 mutex_lock(&wwandev->mhi_dev_lock);
136 if (!wwandev->mhi_dev_open_count++) {
> 137 ret = mhi_prepare_for_transfer(wwandev->mhi_dev, 0);
138 if (!ret)
139 ret = mhi_wwan_ctrl_queue_inbound(wwandev);
140 if (ret)
141 wwandev->mhi_dev_open_count--;
142 }
143 mutex_unlock(&wwandev->mhi_dev_lock);
144
145 if (ret)
146 return ret;
147
148 filp->private_data = wwandev;
149
150 /* stream-like non-seekable file descriptor */
151 stream_open(inode, filp);
152
153 return 0;
154 }
155
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Hi Loic,
I love your patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v5.12-rc3 next-20210319]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Loic-Poulain/bus-mhi-Add-Qcom-WWAN-control-driver/20210309-045313
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 144c79ef33536b4ecb4951e07dbc1f2b7fa99d32
config: s390-allyesconfig (attached as .config)
compiler: s390-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/727df932009e4a00b877f66f9a77658967e0d8a4
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Loic-Poulain/bus-mhi-Add-Qcom-WWAN-control-driver/20210309-045313
git checkout 727df932009e4a00b877f66f9a77658967e0d8a4
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=s390
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
drivers/bus/mhi/wwan_ctrl.c: In function 'mhi_wwan_ctrl_open':
drivers/bus/mhi/wwan_ctrl.c:137:9: error: too many arguments to function 'mhi_prepare_for_transfer'
137 | ret = mhi_prepare_for_transfer(wwandev->mhi_dev, 0);
| ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/bus/mhi/wwan_ctrl.c:5:
include/linux/mhi.h:718:5: note: declared here
718 | int mhi_prepare_for_transfer(struct mhi_device *mhi_dev);
| ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from include/linux/kernel.h:14,
from drivers/bus/mhi/wwan_ctrl.c:4:
drivers/bus/mhi/wwan_ctrl.c: In function 'mhi_wwan_ctrl_probe':
>> drivers/bus/mhi/wwan_ctrl.c:442:48: error: 'MHI_MAX_MTU' undeclared (first use in this function); did you mean 'ETH_MAX_MTU'?
442 | wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
| ^~~~~~~~~~~
include/linux/minmax.h:18:39: note: in definition of macro '__typecheck'
18 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
| ^
include/linux/minmax.h:42:24: note: in expansion of macro '__safe_cmp'
42 | __builtin_choose_expr(__safe_cmp(x, y), \
| ^~~~~~~~~~
include/linux/minmax.h:110:27: note: in expansion of macro '__careful_cmp'
110 | #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
| ^~~~~~~~~~~~~
drivers/bus/mhi/wwan_ctrl.c:442:17: note: in expansion of macro 'min_t'
442 | wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
| ^~~~~
drivers/bus/mhi/wwan_ctrl.c:442:48: note: each undeclared identifier is reported only once for each function it appears in
442 | wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
| ^~~~~~~~~~~
include/linux/minmax.h:18:39: note: in definition of macro '__typecheck'
18 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
| ^
include/linux/minmax.h:42:24: note: in expansion of macro '__safe_cmp'
42 | __builtin_choose_expr(__safe_cmp(x, y), \
| ^~~~~~~~~~
include/linux/minmax.h:110:27: note: in expansion of macro '__careful_cmp'
110 | #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
| ^~~~~~~~~~~~~
drivers/bus/mhi/wwan_ctrl.c:442:17: note: in expansion of macro 'min_t'
442 | wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
| ^~~~~
>> include/linux/minmax.h:42:2: error: first argument to '__builtin_choose_expr' not a constant
42 | __builtin_choose_expr(__safe_cmp(x, y), \
| ^~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:110:27: note: in expansion of macro '__careful_cmp'
110 | #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
| ^~~~~~~~~~~~~
drivers/bus/mhi/wwan_ctrl.c:442:17: note: in expansion of macro 'min_t'
442 | wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
| ^~~~~
drivers/bus/mhi/wwan_ctrl.c: At top level:
drivers/bus/mhi/wwan_ctrl.c:504:53: error: 'MHI_MAX_MTU' undeclared here (not in a function); did you mean 'ETH_MAX_MTU'?
504 | { .chan = MHI_WWAN_CTRL_PROTO_QCDM, .driver_data = MHI_MAX_MTU },
| ^~~~~~~~~~~
| ETH_MAX_MTU
vim +442 drivers/bus/mhi/wwan_ctrl.c
409
410 static int mhi_wwan_ctrl_probe(struct mhi_device *mhi_dev,
411 const struct mhi_device_id *id)
412 {
413 struct mhi_wwan_dev *wwandev;
414 struct device *dev;
415 int index, err;
416
417 /* Create mhi_wwan data context */
418 wwandev = kzalloc(sizeof(*wwandev), GFP_KERNEL);
419 if (!wwandev)
420 return -ENOMEM;
421
422 /* Retrieve index */
423 mutex_lock(&mhi_wwan_ctrl_drv_lock);
424 index = idr_alloc(&mhi_wwan_ctrl_idr, wwandev, 0,
425 MHI_WWAN_CTRL_MAX_MINORS, GFP_KERNEL);
426 mutex_unlock(&mhi_wwan_ctrl_drv_lock);
427 if (index < 0) {
428 err = index;
429 goto err_free_wwandev;
430 }
431
432 /* Init mhi_wwan data */
433 kref_init(&wwandev->ref_count);
434 mutex_init(&wwandev->mhi_dev_lock);
435 mutex_init(&wwandev->write_lock);
436 init_waitqueue_head(&wwandev->ul_wq);
437 init_waitqueue_head(&wwandev->dl_wq);
438 spin_lock_init(&wwandev->dl_queue_lock);
439 INIT_LIST_HEAD(&wwandev->dl_queue);
440 wwandev->mhi_dev = mhi_dev;
441 wwandev->minor = index;
> 442 wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU);
443 set_bit(MHI_WWAN_CONNECTED, &wwandev->flags);
444
445 if (mhi_dev->dl_chan)
446 set_bit(MHI_WWAN_DL_CAP, &wwandev->flags);
447 if (mhi_dev->ul_chan)
448 set_bit(MHI_WWAN_UL_CAP, &wwandev->flags);
449
450 dev_set_drvdata(&mhi_dev->dev, wwandev);
451
452 /* Creates a new device and registers it with sysfs */
453 dev = device_create(mhi_wwan_ctrl_class, &mhi_dev->dev,
454 MKDEV(mhi_wwan_ctrl_major, index), wwandev,
455 "wwan_%s", dev_name(&mhi_dev->dev));
456 if (IS_ERR(dev)) {
457 err = PTR_ERR(dev);
458 goto err_free_idr;
459 }
460
461 return 0;
462
463 err_free_idr:
464 mutex_lock(&mhi_wwan_ctrl_drv_lock);
465 idr_remove(&mhi_wwan_ctrl_idr, wwandev->minor);
466 mutex_unlock(&mhi_wwan_ctrl_drv_lock);
467 err_free_wwandev:
468 kfree(wwandev);
469 dev_set_drvdata(&mhi_dev->dev, NULL);
470
471 return err;
472 };
473
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff --git a/drivers/bus/mhi/Kconfig b/drivers/bus/mhi/Kconfig index da5cd0c..3336ee5 100644 --- a/drivers/bus/mhi/Kconfig +++ b/drivers/bus/mhi/Kconfig @@ -29,3 +29,15 @@ config MHI_BUS_PCI_GENERIC This driver provides MHI PCI controller driver for devices such as Qualcomm SDX55 based PCIe modems. +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 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. diff --git a/drivers/bus/mhi/Makefile b/drivers/bus/mhi/Makefile index 0a2d778..ae25958 100644 --- a/drivers/bus/mhi/Makefile +++ b/drivers/bus/mhi/Makefile @@ -4,3 +4,6 @@ obj-y += core/ obj-$(CONFIG_MHI_BUS_PCI_GENERIC) += mhi_pci_generic.o mhi_pci_generic-y += pci_generic.o +# MHI client +mhi_wwan_ctrl-y := wwan_ctrl.o +obj-$(CONFIG_MHI_WWAN_CTRL) += mhi_wwan_ctrl.o diff --git a/drivers/bus/mhi/wwan_ctrl.c b/drivers/bus/mhi/wwan_ctrl.c new file mode 100644 index 0000000..4e3e993 --- /dev/null +++ b/drivers/bus/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" +#define MHI_WWAN_CTRL_MAX_MINORS 128 + +static DEFINE_IDR(mhi_wwan_ctrl_idr); +static DEFINE_MUTEX(mhi_wwan_ctrl_drv_lock); +static struct class *mhi_wwan_ctrl_class; +static int mhi_wwan_ctrl_major; + +/* WWAN interface Protocols used by user-space for controlling a modem */ +#define MHI_WWAN_CTRL_PROTO_AT "AT" /* AT command protocol */ +#define MHI_WWAN_CTRL_PROTO_MBIM "MBIM" /* Mobile Broadband Interface Model control protocol */ +#define MHI_WWAN_CTRL_PROTO_QMUX "QMI" /* Qcom modem/MSM interface for modem control */ +#define MHI_WWAN_CTRL_PROTO_QCDM "DIAG" /* Qcom Modem diagnostic interface */ +#define MHI_WWAN_CTRL_PROTO_FIREHOSE "FIREHOSE" /* XML based command protocol */ + +/* MHI wwan device flags */ +#define MHI_WWAN_DL_CAP BIT(0) +#define MHI_WWAN_UL_CAP BIT(1) +#define MHI_WWAN_CONNECTED BIT(2) + +struct mhi_wwan_buf { + struct list_head node; + void *data; + size_t len; + size_t consumed; +}; + +struct mhi_wwan_dev { + unsigned int minor; + size_t mtu; + + struct mhi_device *mhi_dev; + /* Protect against concurrent MHI device accesses (start, stop, open, close) */ + struct mutex mhi_dev_lock; + unsigned int mhi_dev_open_count; + + wait_queue_head_t ul_wq; + wait_queue_head_t dl_wq; + + /* Protect download buf queue against concurent update (read/xfer_cb) */ + spinlock_t dl_queue_lock; + struct list_head dl_queue; + + /* For serializing write/queueing to a same MHI channel */ + struct mutex write_lock; + + unsigned long flags; + + /* kref is used to safely track and release a mhi_wwan_dev instance, + * shared between mhi device probe/remove and user open/close. + */ + struct kref ref_count; +}; + +static void mhi_wwan_ctrl_dev_release(struct kref *ref) +{ + struct mhi_wwan_dev *wwandev = container_of(ref, struct mhi_wwan_dev, ref_count); + struct mhi_wwan_buf *buf_itr, *tmp; + + /* Release non consumed buffers */ + list_for_each_entry_safe(buf_itr, tmp, &wwandev->dl_queue, node) { + list_del(&buf_itr->node); + kfree(buf_itr->data); + } + + mutex_destroy(&wwandev->mhi_dev_lock); + mutex_destroy(&wwandev->write_lock); + + kfree(wwandev); +} + +static int mhi_wwan_ctrl_queue_inbound(struct mhi_wwan_dev *wwandev) +{ + struct mhi_device *mhi_dev = wwandev->mhi_dev; + struct device *dev = &mhi_dev->dev; + int nr_desc, i, ret = -EIO; + struct mhi_wwan_buf *ubuf; + void *buf; + + /* + * skip queuing without error if dl channel is not supported. This + * allows open to succeed for udev, supporting ul only channel. + */ + if (!wwandev->mhi_dev->dl_chan) + return 0; + + nr_desc = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE); + + for (i = 0; i < nr_desc; i++) { + buf = kmalloc(wwandev->mtu + sizeof(*ubuf), GFP_KERNEL); + if (!buf) + return -ENOMEM; + + /* save mhi_wwan_buf info at the end of buf */ + ubuf = buf + wwandev->mtu; + ubuf->data = buf; + + ret = mhi_queue_buf(mhi_dev, DMA_FROM_DEVICE, buf, wwandev->mtu, MHI_EOT); + if (ret) { + kfree(buf); + dev_err(dev, "Failed to queue buffer %d\n", i); + return ret; + } + } + + return ret; +} + +static int mhi_wwan_ctrl_open(struct inode *inode, struct file *filp) +{ + unsigned int minor = iminor(inode); + struct mhi_wwan_dev *wwandev = NULL; + int ret = 0; + + /* Retrieve corresponding mhi_wwan_dev and get a reference */ + mutex_lock(&mhi_wwan_ctrl_drv_lock); + wwandev = idr_find(&mhi_wwan_ctrl_idr, minor); + if (!wwandev) { + mutex_unlock(&mhi_wwan_ctrl_drv_lock); + return -ENODEV; + } + kref_get(&wwandev->ref_count); + mutex_unlock(&mhi_wwan_ctrl_drv_lock); + + /* Start MHI channel(s) if not yet started and fill RX queue */ + mutex_lock(&wwandev->mhi_dev_lock); + if (!wwandev->mhi_dev_open_count++) { + ret = mhi_prepare_for_transfer(wwandev->mhi_dev, 0); + if (!ret) + ret = mhi_wwan_ctrl_queue_inbound(wwandev); + if (ret) + wwandev->mhi_dev_open_count--; + } + mutex_unlock(&wwandev->mhi_dev_lock); + + if (ret) + return ret; + + filp->private_data = wwandev; + + /* stream-like non-seekable file descriptor */ + stream_open(inode, filp); + + return 0; +} + +static int mhi_wwan_ctrl_release(struct inode *inode, struct file *file) +{ + struct mhi_wwan_dev *wwandev = file->private_data; + + /* Stop the channels, if not already destroyed */ + mutex_lock(&wwandev->mhi_dev_lock); + if (!(--wwandev->mhi_dev_open_count) && wwandev->mhi_dev) + mhi_unprepare_from_transfer(wwandev->mhi_dev); + mutex_unlock(&wwandev->mhi_dev_lock); + + file->private_data = NULL; + + kref_put(&wwandev->ref_count, mhi_wwan_ctrl_dev_release); + + return 0; +} + +static __poll_t mhi_wwan_ctrl_poll(struct file *file, poll_table *wait) +{ + struct mhi_wwan_dev *wwandev = file->private_data; + __poll_t mask = 0; + + poll_wait(file, &wwandev->ul_wq, wait); + poll_wait(file, &wwandev->dl_wq, wait); + + /* Any buffer in the DL queue ? */ + spin_lock_bh(&wwandev->dl_queue_lock); + if (!list_empty(&wwandev->dl_queue)) + mask |= EPOLLIN | EPOLLRDNORM; + spin_unlock_bh(&wwandev->dl_queue_lock); + + /* If MHI queue is not full, write is possible */ + mutex_lock(&wwandev->mhi_dev_lock); + if (!wwandev->mhi_dev) + mask = EPOLLERR | EPOLLHUP; + else if (!mhi_queue_is_full(wwandev->mhi_dev, DMA_TO_DEVICE)) + mask |= EPOLLOUT | EPOLLWRNORM; + mutex_unlock(&wwandev->mhi_dev_lock); + + return mask; +} + +static ssize_t mhi_wwan_ctrl_write(struct file *file, const char __user *buf, + size_t count, loff_t *offp) +{ + struct mhi_wwan_dev *wwandev = file->private_data; + size_t bytes_xfered = 0; + void *kbuf = NULL; + int ret; + + if (!test_bit(MHI_WWAN_UL_CAP, &wwandev->flags)) + return -EOPNOTSUPP; + + if (!buf || !count) + return -EINVAL; + + /* Serialize MHI queueing */ + if (mutex_lock_interruptible(&wwandev->write_lock)) + return -EINTR; + + while (count) { + size_t xfer_size; + + /* Wait for available transfer descriptor */ + ret = wait_event_interruptible(wwandev->ul_wq, + !test_bit(MHI_WWAN_CONNECTED, &wwandev->flags) || + !mhi_queue_is_full(wwandev->mhi_dev, DMA_TO_DEVICE)); + if (ret) + break; + + if (!test_bit(MHI_WWAN_CONNECTED, &wwandev->flags)) { + ret = -EPIPE; + break; + } + + xfer_size = min_t(size_t, count, wwandev->mtu); + kbuf = kmalloc(xfer_size, GFP_KERNEL); + if (!kbuf) { + ret = -ENOMEM; + break; + } + + ret = copy_from_user(kbuf, buf, xfer_size); + if (ret) + break; + + /* Add buffer to MHI queue */ + ret = mhi_queue_buf(wwandev->mhi_dev, DMA_TO_DEVICE, kbuf, + xfer_size, MHI_EOT); + if (ret) + break; + + bytes_xfered += xfer_size; + count -= xfer_size; + buf += xfer_size; + kbuf = NULL; + } + + mutex_unlock(&wwandev->write_lock); + + kfree(kbuf); + + return ret ? ret : bytes_xfered; +} + +static int mhi_wwan_ctrl_recycle_ubuf(struct mhi_wwan_dev *wwandev, + struct mhi_wwan_buf *ubuf) +{ + int ret; + + mutex_lock(&wwandev->mhi_dev_lock); + + if (!wwandev->mhi_dev) { + ret = -ENODEV; + goto exit_unlock; + } + + ret = mhi_queue_buf(wwandev->mhi_dev, DMA_FROM_DEVICE, ubuf->data, + wwandev->mtu, MHI_EOT); + +exit_unlock: + mutex_unlock(&wwandev->mhi_dev_lock); + + return ret; +} + +static ssize_t mhi_wwan_ctrl_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct mhi_wwan_dev *wwandev = file->private_data; + bool recycle_buf = false; + struct mhi_wwan_buf *ubuf; + size_t copy_len; + char *copy_ptr; + int ret = 0; + + if (!test_bit(MHI_WWAN_DL_CAP, &wwandev->flags)) + return -EOPNOTSUPP; + + if (!buf) + return -EINVAL; + + spin_lock_irq(&wwandev->dl_queue_lock); + + /* Wait for at least one buffer in the dl queue (or device removal) */ + ret = wait_event_interruptible_lock_irq(wwandev->dl_wq, + !list_empty(&wwandev->dl_queue) || + !test_bit(MHI_WWAN_CONNECTED, &wwandev->flags), + wwandev->dl_queue_lock); + if (ret) { + goto err_unlock; + } else if (!test_bit(MHI_WWAN_CONNECTED, &wwandev->flags)) { + ret = -EPIPE; + goto err_unlock; + } + + ubuf = list_first_entry_or_null(&wwandev->dl_queue, struct mhi_wwan_buf, node); + if (!ubuf) { + ret = -EIO; + goto err_unlock; + } + + /* Consume the buffer */ + copy_len = min_t(size_t, count, ubuf->len - ubuf->consumed); + copy_ptr = ubuf->data + ubuf->consumed; + ubuf->consumed += copy_len; + + /* Remove buffer from the DL queue if entirely consumed */ + if (ubuf->consumed == ubuf->len) { + list_del(&ubuf->node); + recycle_buf = true; + } + + spin_unlock_irq(&wwandev->dl_queue_lock); + + ret = copy_to_user(buf, copy_ptr, copy_len); + if (ret) + return -EFAULT; + + if (recycle_buf) { + /* Give the buffer back to MHI queue */ + ret = mhi_wwan_ctrl_recycle_ubuf(wwandev, ubuf); + if (ret) /* unable to recycle, release */ + kfree(ubuf->data); + } + + return copy_len; + +err_unlock: + spin_unlock_irq(&wwandev->dl_queue_lock); + + return ret; +} + +static const struct file_operations mhidev_fops = { + .owner = THIS_MODULE, + .open = mhi_wwan_ctrl_open, + .release = mhi_wwan_ctrl_release, + .read = mhi_wwan_ctrl_read, + .write = mhi_wwan_ctrl_write, + .poll = mhi_wwan_ctrl_poll, +}; + +static void mhi_ul_xfer_cb(struct mhi_device *mhi_dev, + struct mhi_result *mhi_result) +{ + struct mhi_wwan_dev *wwandev = dev_get_drvdata(&mhi_dev->dev); + struct device *dev = &mhi_dev->dev; + + dev_dbg(dev, "%s: status: %d xfer_len: %zu\n", __func__, + mhi_result->transaction_status, mhi_result->bytes_xferd); + + kfree(mhi_result->buf_addr); + + /* Some space available in the 'upload' queue, advertise that */ + if (!mhi_result->transaction_status) + wake_up_interruptible(&wwandev->ul_wq); +} + +static void mhi_dl_xfer_cb(struct mhi_device *mhi_dev, + struct mhi_result *mhi_result) +{ + struct mhi_wwan_dev *wwandev = dev_get_drvdata(&mhi_dev->dev); + struct mhi_wwan_buf *ubuf; + + dev_dbg(&mhi_dev->dev, "%s: status: %d receive_len: %zu\n", __func__, + mhi_result->transaction_status, mhi_result->bytes_xferd); + + if (mhi_result->transaction_status && + mhi_result->transaction_status != -EOVERFLOW) { + kfree(mhi_result->buf_addr); + return; + } + + /* ubuf is placed at the end of the buffer (cf mhi_wwan_ctrl_queue_inbound) */ + ubuf = mhi_result->buf_addr + wwandev->mtu; + + /* paranoia, should never happen */ + if (WARN_ON(mhi_result->buf_addr != ubuf->data)) { + kfree(mhi_result->buf_addr); + return; + } + + ubuf->data = mhi_result->buf_addr; + ubuf->len = mhi_result->bytes_xferd; + ubuf->consumed = 0; + + spin_lock_bh(&wwandev->dl_queue_lock); + list_add_tail(&ubuf->node, &wwandev->dl_queue); + spin_unlock_bh(&wwandev->dl_queue_lock); + + wake_up_interruptible(&wwandev->dl_wq); +} + +static int mhi_wwan_ctrl_probe(struct mhi_device *mhi_dev, + const struct mhi_device_id *id) +{ + struct mhi_wwan_dev *wwandev; + struct device *dev; + int index, err; + + /* Create mhi_wwan data context */ + wwandev = kzalloc(sizeof(*wwandev), GFP_KERNEL); + if (!wwandev) + return -ENOMEM; + + /* Retrieve index */ + mutex_lock(&mhi_wwan_ctrl_drv_lock); + index = idr_alloc(&mhi_wwan_ctrl_idr, wwandev, 0, + MHI_WWAN_CTRL_MAX_MINORS, GFP_KERNEL); + mutex_unlock(&mhi_wwan_ctrl_drv_lock); + if (index < 0) { + err = index; + goto err_free_wwandev; + } + + /* Init mhi_wwan data */ + kref_init(&wwandev->ref_count); + mutex_init(&wwandev->mhi_dev_lock); + mutex_init(&wwandev->write_lock); + init_waitqueue_head(&wwandev->ul_wq); + init_waitqueue_head(&wwandev->dl_wq); + spin_lock_init(&wwandev->dl_queue_lock); + INIT_LIST_HEAD(&wwandev->dl_queue); + wwandev->mhi_dev = mhi_dev; + wwandev->minor = index; + wwandev->mtu = min_t(size_t, id->driver_data, MHI_MAX_MTU); + set_bit(MHI_WWAN_CONNECTED, &wwandev->flags); + + if (mhi_dev->dl_chan) + set_bit(MHI_WWAN_DL_CAP, &wwandev->flags); + if (mhi_dev->ul_chan) + set_bit(MHI_WWAN_UL_CAP, &wwandev->flags); + + dev_set_drvdata(&mhi_dev->dev, wwandev); + + /* Creates a new device and registers it with sysfs */ + dev = device_create(mhi_wwan_ctrl_class, &mhi_dev->dev, + MKDEV(mhi_wwan_ctrl_major, index), wwandev, + "wwan_%s", dev_name(&mhi_dev->dev)); + if (IS_ERR(dev)) { + err = PTR_ERR(dev); + goto err_free_idr; + } + + return 0; + +err_free_idr: + mutex_lock(&mhi_wwan_ctrl_drv_lock); + idr_remove(&mhi_wwan_ctrl_idr, wwandev->minor); + mutex_unlock(&mhi_wwan_ctrl_drv_lock); +err_free_wwandev: + kfree(wwandev); + dev_set_drvdata(&mhi_dev->dev, NULL); + + return err; +}; + +static void mhi_wwan_ctrl_remove(struct mhi_device *mhi_dev) +{ + struct mhi_wwan_dev *wwandev = dev_get_drvdata(&mhi_dev->dev); + + dev_set_drvdata(&mhi_dev->dev, NULL); + + mutex_lock(&mhi_wwan_ctrl_drv_lock); + idr_remove(&mhi_wwan_ctrl_idr, wwandev->minor); + mutex_unlock(&mhi_wwan_ctrl_drv_lock); + + clear_bit(MHI_WWAN_CONNECTED, &wwandev->flags); + device_destroy(mhi_wwan_ctrl_class, MKDEV(mhi_wwan_ctrl_major, wwandev->minor)); + + /* Unlink mhi_dev from mhi_wwan_dev */ + mutex_lock(&wwandev->mhi_dev_lock); + wwandev->mhi_dev = NULL; + mutex_unlock(&wwandev->mhi_dev_lock); + + /* wake up any blocked user */ + wake_up_interruptible(&wwandev->dl_wq); + wake_up_interruptible(&wwandev->ul_wq); + + kref_put(&wwandev->ref_count, mhi_wwan_ctrl_dev_release); +} + +/* .driver_data stores max mtu */ +static const struct mhi_device_id mhi_wwan_ctrl_match_table[] = { + { .chan = MHI_WWAN_CTRL_PROTO_AT, .driver_data = 4096 }, + { .chan = MHI_WWAN_CTRL_PROTO_MBIM, .driver_data = 4096 }, + { .chan = MHI_WWAN_CTRL_PROTO_QMUX, .driver_data = 4096 }, + { .chan = MHI_WWAN_CTRL_PROTO_QCDM, .driver_data = MHI_MAX_MTU }, + { .chan = MHI_WWAN_CTRL_PROTO_FIREHOSE, .driver_data = MHI_MAX_MTU }, + {}, +}; +MODULE_DEVICE_TABLE(mhi, mhi_wwan_ctrl_match_table); + +static struct mhi_driver mhi_wwan_ctrl_driver = { + .id_table = mhi_wwan_ctrl_match_table, + .remove = mhi_wwan_ctrl_remove, + .probe = mhi_wwan_ctrl_probe, + .ul_xfer_cb = mhi_ul_xfer_cb, + .dl_xfer_cb = mhi_dl_xfer_cb, + .driver = { + .name = MHI_WWAN_CTRL_DRIVER_NAME, + }, +}; + +static int __init mhi_wwan_ctrl_init(void) +{ + int ret; + + ret = register_chrdev(0, MHI_WWAN_CTRL_DRIVER_NAME, &mhidev_fops); + if (ret < 0) + return ret; + + mhi_wwan_ctrl_major = ret; + mhi_wwan_ctrl_class = class_create(THIS_MODULE, MHI_WWAN_CTRL_DRIVER_NAME); + if (IS_ERR(mhi_wwan_ctrl_class)) { + unregister_chrdev(mhi_wwan_ctrl_major, MHI_WWAN_CTRL_DRIVER_NAME); + return PTR_ERR(mhi_wwan_ctrl_class); + } + + ret = mhi_driver_register(&mhi_wwan_ctrl_driver); + if (ret) { + class_destroy(mhi_wwan_ctrl_class); + unregister_chrdev(mhi_wwan_ctrl_major, MHI_WWAN_CTRL_DRIVER_NAME); + } + + return ret; +} + +static void __exit mhi_wwan_ctrl_exit(void) +{ + mhi_driver_unregister(&mhi_wwan_ctrl_driver); + class_destroy(mhi_wwan_ctrl_class); + unregister_chrdev(mhi_wwan_ctrl_major, MHI_WWAN_CTRL_DRIVER_NAME); + idr_destroy(&mhi_wwan_ctrl_idr); +} + +module_init(mhi_wwan_ctrl_init); +module_exit(mhi_wwan_ctrl_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("MHI WWAN CTRL Driver"); +MODULE_AUTHOR("Hemant Kumar <hemantk@codeaurora.org>"); +MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");