From 60302ce4ea075369641426ef407c110e36ea8ba1 Mon Sep 17 00:00:00 2001 From: Stephan Gerhold Date: Fri, 18 Jun 2021 19:36:09 +0200 Subject: rpmsg: core: Add driver_data for rpmsg_device_id Most device_id structs provide a driver_data field that can be used by drivers to associate data more easily for a particular device ID. Add the same for the rpmsg_device_id. Cc: Bjorn Andersson Signed-off-by: Stephan Gerhold Signed-off-by: David S. Miller --- drivers/rpmsg/rpmsg_core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c index e5daee4f9373..c1404d3dae2c 100644 --- a/drivers/rpmsg/rpmsg_core.c +++ b/drivers/rpmsg/rpmsg_core.c @@ -459,8 +459,10 @@ static int rpmsg_dev_match(struct device *dev, struct device_driver *drv) if (ids) for (i = 0; ids[i].name[0]; i++) - if (rpmsg_id_match(rpdev, &ids[i])) + if (rpmsg_id_match(rpdev, &ids[i])) { + rpdev->id.driver_data = ids[i].driver_data; return 1; + } return of_driver_match_device(dev, drv); } -- cgit 1.4.1 From 5e90abf49c2adfbd6954429c2a1aafdfe9fcab92 Mon Sep 17 00:00:00 2001 From: Stephan Gerhold Date: Fri, 18 Jun 2021 19:36:10 +0200 Subject: net: wwan: Add RPMSG WWAN CTRL driver The remote processor messaging (rpmsg) subsystem provides an interface to communicate with other remote processors. On many Qualcomm SoCs this is used to communicate with an integrated modem DSP that implements most of the modem functionality and provides high-level protocols like QMI or AT to allow controlling the modem. For QMI, most older Qualcomm SoCs (e.g. MSM8916/MSM8974) have a standalone "DATA5_CNTL" channel that allows exchanging QMI messages. Note that newer SoCs (e.g. SDM845) only allow exchanging QMI messages via a shared QRTR channel that is available via a socket API on Linux. For AT, the "DATA4" channel accepts at least a limited set of AT commands, on many older and newer Qualcomm SoCs, although QMI is typically the preferred control protocol. Often there are additional QMI/AT channels (usually named DATA*_CNTL for QMI and DATA* for AT), but it is not clear if those are really functional on all devices. Also, at the moment there is no use case for having multiple QMI/AT ports. If needed more channels could be added later after more testing. Note that the data path (network interface) is entirely separate from the control path and varies between Qualcomm SoCs, e.g. "IPA" on newer Qualcomm SoCs or "BAM-DMUX" on some older ones. The RPMSG WWAN CTRL driver exposes the QMI/AT control ports via the WWAN subsystem, and therefore allows userspace like ModemManager to set up the modem. Until now, ModemManager had to use the RPMSG-specific rpmsg-char where the channels must be explicitly exposed as a char device first and don't show up directly in sysfs. The driver is a fairly simple glue layer between WWAN and RPMSG and is mostly based on the existing mhi_wwan_ctrl.c and rpmsg_char.c. Cc: Loic Poulain Cc: Bjorn Andersson Signed-off-by: Stephan Gerhold Signed-off-by: David S. Miller --- MAINTAINERS | 7 ++ drivers/net/wwan/Kconfig | 18 +++++ drivers/net/wwan/Makefile | 1 + drivers/net/wwan/rpmsg_wwan_ctrl.c | 143 +++++++++++++++++++++++++++++++++++++ 4 files changed, 169 insertions(+) create mode 100644 drivers/net/wwan/rpmsg_wwan_ctrl.c (limited to 'drivers') diff --git a/MAINTAINERS b/MAINTAINERS index 183cc61e2dc0..fbf792962d7b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15587,6 +15587,13 @@ F: include/linux/rpmsg/ F: include/uapi/linux/rpmsg.h F: samples/rpmsg/ +REMOTE PROCESSOR MESSAGING (RPMSG) WWAN CONTROL DRIVER +M: Stephan Gerhold +L: netdev@vger.kernel.org +L: linux-remoteproc@vger.kernel.org +S: Maintained +F: drivers/net/wwan/rpmsg_wwan_ctrl.c + RENESAS CLOCK DRIVERS M: Geert Uytterhoeven L: linux-renesas-soc@vger.kernel.org diff --git a/drivers/net/wwan/Kconfig b/drivers/net/wwan/Kconfig index 249b3f1ed62b..de9384326bc8 100644 --- a/drivers/net/wwan/Kconfig +++ b/drivers/net/wwan/Kconfig @@ -38,6 +38,24 @@ config MHI_WWAN_CTRL To compile this driver as a module, choose M here: the module will be called mhi_wwan_ctrl. +config RPMSG_WWAN_CTRL + tristate "RPMSG WWAN control driver" + depends on RPMSG + help + RPMSG WWAN CTRL allows modems available via RPMSG channels to expose + different modem protocols/ports to userspace, including AT and QMI. + These protocols can be accessed directly from userspace + (e.g. AT commands) or via libraries/tools (e.g. libqmi, libqcdm...). + + This is mainly used for modems integrated into many Qualcomm SoCs, + e.g. for AT and QMI on Qualcomm MSM8916 or MSM8974. Note that many + newer Qualcomm SoCs (e.g. SDM845) still provide an AT port through + this driver but the QMI messages can only be sent through + QRTR network sockets (CONFIG_QRTR). + + To compile this driver as a module, choose M here: the module will be + called rpmsg_wwan_ctrl. + config IOSM tristate "IOSM Driver for Intel M.2 WWAN Device" depends on INTEL_IOMMU diff --git a/drivers/net/wwan/Makefile b/drivers/net/wwan/Makefile index 83dd3482ffc3..d90ac33abaef 100644 --- a/drivers/net/wwan/Makefile +++ b/drivers/net/wwan/Makefile @@ -9,4 +9,5 @@ wwan-objs += wwan_core.o obj-$(CONFIG_WWAN_HWSIM) += wwan_hwsim.o obj-$(CONFIG_MHI_WWAN_CTRL) += mhi_wwan_ctrl.o +obj-$(CONFIG_RPMSG_WWAN_CTRL) += rpmsg_wwan_ctrl.o obj-$(CONFIG_IOSM) += iosm/ diff --git a/drivers/net/wwan/rpmsg_wwan_ctrl.c b/drivers/net/wwan/rpmsg_wwan_ctrl.c new file mode 100644 index 000000000000..de226cdb69fd --- /dev/null +++ b/drivers/net/wwan/rpmsg_wwan_ctrl.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2021, Stephan Gerhold */ +#include +#include +#include +#include +#include +#include + +struct rpmsg_wwan_dev { + /* Lower level is a rpmsg dev, upper level is a wwan port */ + struct rpmsg_device *rpdev; + struct wwan_port *wwan_port; + struct rpmsg_endpoint *ept; +}; + +static int rpmsg_wwan_ctrl_callback(struct rpmsg_device *rpdev, + void *buf, int len, void *priv, u32 src) +{ + struct rpmsg_wwan_dev *rpwwan = priv; + struct sk_buff *skb; + + skb = alloc_skb(len, GFP_ATOMIC); + if (!skb) + return -ENOMEM; + + skb_put_data(skb, buf, len); + wwan_port_rx(rpwwan->wwan_port, skb); + return 0; +} + +static int rpmsg_wwan_ctrl_start(struct wwan_port *port) +{ + struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port); + struct rpmsg_channel_info chinfo = { + .src = rpwwan->rpdev->src, + .dst = RPMSG_ADDR_ANY, + }; + + strncpy(chinfo.name, rpwwan->rpdev->id.name, RPMSG_NAME_SIZE); + rpwwan->ept = rpmsg_create_ept(rpwwan->rpdev, rpmsg_wwan_ctrl_callback, + rpwwan, chinfo); + if (!rpwwan->ept) + return -EREMOTEIO; + + return 0; +} + +static void rpmsg_wwan_ctrl_stop(struct wwan_port *port) +{ + struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port); + + rpmsg_destroy_ept(rpwwan->ept); + rpwwan->ept = NULL; +} + +static int rpmsg_wwan_ctrl_tx(struct wwan_port *port, struct sk_buff *skb) +{ + struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port); + int ret; + + ret = rpmsg_trysend(rpwwan->ept, skb->data, skb->len); + if (ret) + return ret; + + consume_skb(skb); + return 0; +} + +static const struct wwan_port_ops rpmsg_wwan_pops = { + .start = rpmsg_wwan_ctrl_start, + .stop = rpmsg_wwan_ctrl_stop, + .tx = rpmsg_wwan_ctrl_tx, +}; + +static struct device *rpmsg_wwan_find_parent(struct device *dev) +{ + /* Select first platform device as parent for the WWAN ports. + * On Qualcomm platforms this is usually the platform device that + * represents the modem remote processor. This might need to be + * adjusted when adding device IDs for other platforms. + */ + for (dev = dev->parent; dev; dev = dev->parent) { + if (dev_is_platform(dev)) + return dev; + } + return NULL; +} + +static int rpmsg_wwan_ctrl_probe(struct rpmsg_device *rpdev) +{ + struct rpmsg_wwan_dev *rpwwan; + struct wwan_port *port; + struct device *parent; + + parent = rpmsg_wwan_find_parent(&rpdev->dev); + if (!parent) + return -ENODEV; + + rpwwan = devm_kzalloc(&rpdev->dev, sizeof(*rpwwan), GFP_KERNEL); + if (!rpwwan) + return -ENOMEM; + + rpwwan->rpdev = rpdev; + dev_set_drvdata(&rpdev->dev, rpwwan); + + /* Register as a wwan port, id.driver_data contains wwan port type */ + port = wwan_create_port(parent, rpdev->id.driver_data, + &rpmsg_wwan_pops, rpwwan); + if (IS_ERR(port)) + return PTR_ERR(port); + + rpwwan->wwan_port = port; + + return 0; +}; + +static void rpmsg_wwan_ctrl_remove(struct rpmsg_device *rpdev) +{ + struct rpmsg_wwan_dev *rpwwan = dev_get_drvdata(&rpdev->dev); + + wwan_remove_port(rpwwan->wwan_port); +} + +static const struct rpmsg_device_id rpmsg_wwan_ctrl_id_table[] = { + /* RPMSG channels for Qualcomm SoCs with integrated modem */ + { .name = "DATA5_CNTL", .driver_data = WWAN_PORT_QMI }, + { .name = "DATA4", .driver_data = WWAN_PORT_AT }, + {}, +}; +MODULE_DEVICE_TABLE(rpmsg, rpmsg_wwan_ctrl_id_table); + +static struct rpmsg_driver rpmsg_wwan_ctrl_driver = { + .drv.name = "rpmsg_wwan_ctrl", + .id_table = rpmsg_wwan_ctrl_id_table, + .probe = rpmsg_wwan_ctrl_probe, + .remove = rpmsg_wwan_ctrl_remove, +}; +module_rpmsg_driver(rpmsg_wwan_ctrl_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("RPMSG WWAN CTRL Driver"); +MODULE_AUTHOR("Stephan Gerhold "); -- cgit 1.4.1 From 31c143f712750143abaca396236bbe8707700111 Mon Sep 17 00:00:00 2001 From: Stephan Gerhold Date: Fri, 18 Jun 2021 19:36:11 +0200 Subject: net: wwan: Allow WWAN drivers to provide blocking tx and poll function At the moment, the WWAN core provides wwan_port_txon/off() to implement blocking writes. The tx() port operation should not block, instead wwan_port_txon/off() should be called when the TX queue is full or has free space again. However, in some cases it is not straightforward to make use of that functionality. For example, the RPMSG API used by rpmsg_wwan_ctrl.c does not provide any way to be notified when the TX queue has space again. Instead, it only provides the following operations: - rpmsg_send(): blocking write (wait until there is space) - rpmsg_trysend(): non-blocking write (return error if no space) - rpmsg_poll(): set poll flags depending on TX queue state Generally that's totally sufficient for implementing a char device, but it does not fit well to the currently provided WWAN port ops. Most of the time, using the non-blocking rpmsg_trysend() in the WWAN tx() port operation works just fine. However, with high-frequent writes to the char device it is possible to trigger a situation where this causes issues. For example, consider the following (somewhat unrealistic) example: # dd if=/dev/zero bs=1000 of=/dev/wwan0qmi0 dd: error writing '/dev/wwan0qmi0': Resource temporarily unavailable 1+0 records out This fails immediately after writing the first record. It's likely only a matter of time until this triggers issues for some real application (e.g. ModemManager sending a lot of large QMI packets). The rpmsg_char device does not have this problem, because it uses rpmsg_trysend() and rpmsg_poll() to support non-blocking operations. Make it possible to use the same in the RPMSG WWAN driver by adding two new optional wwan_port_ops: - tx_blocking(): send data blocking if allowed - tx_poll(): set additional TX poll flags This integrates nicely with the RPMSG API and does not require any change in existing WWAN drivers. With these changes, the dd example above blocks instead of exiting with an error. Cc: Loic Poulain Signed-off-by: Stephan Gerhold Signed-off-by: David S. Miller --- drivers/net/wwan/rpmsg_wwan_ctrl.c | 23 +++++++++++++++++++++++ drivers/net/wwan/wwan_core.c | 16 ++++++++++++---- include/linux/wwan.h | 13 +++++++++++-- 3 files changed, 46 insertions(+), 6 deletions(-) (limited to 'drivers') diff --git a/drivers/net/wwan/rpmsg_wwan_ctrl.c b/drivers/net/wwan/rpmsg_wwan_ctrl.c index de226cdb69fd..31c24420ab2e 100644 --- a/drivers/net/wwan/rpmsg_wwan_ctrl.c +++ b/drivers/net/wwan/rpmsg_wwan_ctrl.c @@ -67,10 +67,33 @@ static int rpmsg_wwan_ctrl_tx(struct wwan_port *port, struct sk_buff *skb) return 0; } +static int rpmsg_wwan_ctrl_tx_blocking(struct wwan_port *port, struct sk_buff *skb) +{ + struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port); + int ret; + + ret = rpmsg_send(rpwwan->ept, skb->data, skb->len); + if (ret) + return ret; + + consume_skb(skb); + return 0; +} + +static __poll_t rpmsg_wwan_ctrl_tx_poll(struct wwan_port *port, + struct file *filp, poll_table *wait) +{ + struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port); + + return rpmsg_poll(rpwwan->ept, filp, wait); +} + static const struct wwan_port_ops rpmsg_wwan_pops = { .start = rpmsg_wwan_ctrl_start, .stop = rpmsg_wwan_ctrl_stop, .tx = rpmsg_wwan_ctrl_tx, + .tx_blocking = rpmsg_wwan_ctrl_tx_blocking, + .tx_poll = rpmsg_wwan_ctrl_tx_poll, }; static struct device *rpmsg_wwan_find_parent(struct device *dev) diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c index 7e728042fc41..165afec1dbd1 100644 --- a/drivers/net/wwan/wwan_core.c +++ b/drivers/net/wwan/wwan_core.c @@ -500,7 +500,8 @@ static void wwan_port_op_stop(struct wwan_port *port) mutex_unlock(&port->ops_lock); } -static int wwan_port_op_tx(struct wwan_port *port, struct sk_buff *skb) +static int wwan_port_op_tx(struct wwan_port *port, struct sk_buff *skb, + bool nonblock) { int ret; @@ -510,7 +511,10 @@ static int wwan_port_op_tx(struct wwan_port *port, struct sk_buff *skb) goto out_unlock; } - ret = port->ops->tx(port, skb); + if (nonblock || !port->ops->tx_blocking) + ret = port->ops->tx(port, skb); + else + ret = port->ops->tx_blocking(port, skb); out_unlock: mutex_unlock(&port->ops_lock); @@ -637,7 +641,7 @@ static ssize_t wwan_port_fops_write(struct file *filp, const char __user *buf, return -EFAULT; } - ret = wwan_port_op_tx(port, skb); + ret = wwan_port_op_tx(port, skb, !!(filp->f_flags & O_NONBLOCK)); if (ret) { kfree_skb(skb); return ret; @@ -653,12 +657,16 @@ static __poll_t wwan_port_fops_poll(struct file *filp, poll_table *wait) poll_wait(filp, &port->waitqueue, wait); - if (!is_write_blocked(port)) + mutex_lock(&port->ops_lock); + if (port->ops && port->ops->tx_poll) + mask |= port->ops->tx_poll(port, filp, wait); + else if (!is_write_blocked(port)) mask |= EPOLLOUT | EPOLLWRNORM; if (!is_read_blocked(port)) mask |= EPOLLIN | EPOLLRDNORM; if (!port->ops) mask |= EPOLLHUP | EPOLLERR; + mutex_unlock(&port->ops_lock); return mask; } diff --git a/include/linux/wwan.h b/include/linux/wwan.h index 430a3a0817de..34222230360c 100644 --- a/include/linux/wwan.h +++ b/include/linux/wwan.h @@ -6,6 +6,7 @@ #include #include +#include #include #include @@ -40,15 +41,23 @@ struct wwan_port; /** struct wwan_port_ops - The WWAN port operations * @start: The routine for starting the WWAN port device. * @stop: The routine for stopping the WWAN port device. - * @tx: The routine that sends WWAN port protocol data to the device. + * @tx: Non-blocking routine that sends WWAN port protocol data to the device. + * @tx_blocking: Optional blocking routine that sends WWAN port protocol data + * to the device. + * @tx_poll: Optional routine that sets additional TX poll flags. * * The wwan_port_ops structure contains a list of low-level operations - * that control a WWAN port device. All functions are mandatory. + * that control a WWAN port device. All functions are mandatory unless specified. */ struct wwan_port_ops { int (*start)(struct wwan_port *port); void (*stop)(struct wwan_port *port); int (*tx)(struct wwan_port *port, struct sk_buff *skb); + + /* Optional operations */ + int (*tx_blocking)(struct wwan_port *port, struct sk_buff *skb); + __poll_t (*tx_poll)(struct wwan_port *port, struct file *filp, + poll_table *wait); }; /** -- cgit 1.4.1