| Message ID | 20201222105726.16906-2-arnaud.pouliquen@foss.st.com |
|---|---|
| State | New |
| Headers | show |
| Series | introduce generic IOCTL interface for RPMsg channels management | expand |
On Tue 22 Dec 04:57 CST 2020, Arnaud Pouliquen wrote: > The RPMsg_ctrl driver is a duplication of the ioctrl part of the > rpmsg_char driver to make generic the ioctl to manage channels by > the userspace applications. > > As a first step, this driver just creates the /dev/rpmsg_ctl<x> > ( <x> is the instance value). The ioctl is not implemented. > > Notice that this driver is associated to a RPMsg device with no endpoint. > Instantiating this device as an RPMsg device allows to retrieve the > associated RPMsg backend. > I think it would make more sense to make the rpmsg_char driver do what you want and then cleanly extract the "control" code out of it to a separate file - than to create a duplicate implementation and then retire the other one. In particular I think that would show the difference between the two better. > Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> > --- > drivers/rpmsg/Kconfig | 8 ++ > drivers/rpmsg/Makefile | 1 + > drivers/rpmsg/rpmsg_ctrl.c | 208 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 217 insertions(+) > create mode 100644 drivers/rpmsg/rpmsg_ctrl.c > > diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig > index 0b4407abdf13..c9e602016c3b 100644 > --- a/drivers/rpmsg/Kconfig > +++ b/drivers/rpmsg/Kconfig > @@ -23,6 +23,14 @@ config RPMSG_NS > channel that probes the associated RPMsg device on remote endpoint > service announcement. > > +config RPMSG_CTRL > + tristate "RPMSG control interface" > + depends on RPMSG > + help > + Say Y here to enable the support of the /dev/rpmsg_ctl API. this API > + allows user-space programs to create channels with specific name, > + source and destination addresses. > + > config RPMSG_MTK_SCP > tristate "MediaTek SCP" > depends on MTK_SCP > diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile > index 8d452656f0ee..3c1bce9d0228 100644 > --- a/drivers/rpmsg/Makefile > +++ b/drivers/rpmsg/Makefile > @@ -2,6 +2,7 @@ > obj-$(CONFIG_RPMSG) += rpmsg_core.o > obj-$(CONFIG_RPMSG_CHAR) += rpmsg_char.o > obj-$(CONFIG_RPMSG_NS) += rpmsg_ns.o > +obj-$(CONFIG_RPMSG_CTRL) += rpmsg_ctrl.o > obj-$(CONFIG_RPMSG_MTK_SCP) += mtk_rpmsg.o > qcom_glink-objs := qcom_glink_native.o qcom_glink_ssr.o > obj-$(CONFIG_RPMSG_QCOM_GLINK) += qcom_glink.o > diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c > new file mode 100644 > index 000000000000..425c3e32ada4 > --- /dev/null > +++ b/drivers/rpmsg/rpmsg_ctrl.c > @@ -0,0 +1,208 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) STMicroelectronics 2020 This is pretty much a verbatim copy of rpmsg_char and as such STMicroelectronics is not the appropriate/sole copyright holder of the content. Regards, Bjorn > + */ > + > +#include <linux/cdev.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/slab.h> > +#include "rpmsg_internal.h" > +#include <uapi/linux/rpmsg.h> > + > +#define RPMSG_DEV_MAX (MINORMASK + 1) > + > +#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrl_dev, dev) > +#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrl_dev, cdev) > + > +/** > + * struct rpmsg_ctrl_dev - control device for instantiating endpoint devices > + * @rpdev: underlaying rpmsg device > + * @cdev: cdev for the ctrl device > + * @dev: device for the ctrl device > + */ > +struct rpmsg_ctrl_dev { > + struct rpmsg_device *rpdev; > + struct cdev cdev; > + struct device dev; > +}; > + > +static DEFINE_IDA(rpmsg_ctrl_ida); > +static DEFINE_IDA(rpmsg_minor_ida); > + > +static dev_t rpmsg_major; > + > +static int rpmsg_ctrl_dev_open(struct inode *inode, struct file *filp) > +{ > + struct rpmsg_ctrl_dev *ctrldev = cdev_to_ctrldev(inode->i_cdev); > + > + get_device(&ctrldev->dev); > + filp->private_data = ctrldev; > + > + return 0; > +} > + > +static long rpmsg_ctrl_dev_ioctl(struct file *fp, unsigned int cmd, > + unsigned long arg) > +{ > + struct rpmsg_ctrl_dev *ctrldev = fp->private_data; > + > + dev_info(&ctrldev->dev, "Control not yet implemented\n"); > + > + return 0; > +}; > + > +static int rpmsg_ctrl_dev_release(struct inode *inode, struct file *filp) > +{ > + struct rpmsg_ctrl_dev *ctrldev = cdev_to_ctrldev(inode->i_cdev); > + > + put_device(&ctrldev->dev); > + > + return 0; > +} > + > +static void rpmsg_ctrl_dev_release_device(struct device *dev) > +{ > + struct rpmsg_ctrl_dev *ctrldev = dev_to_ctrldev(dev); > + > + dev_err(dev, "%s\n", __func__); > + > + ida_simple_remove(&rpmsg_ctrl_ida, dev->id); > + ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); > + cdev_del(&ctrldev->cdev); > + kfree(ctrldev); > +} > + > +static const struct file_operations rpmsg_ctrl_fops = { > + .owner = THIS_MODULE, > + .open = rpmsg_ctrl_dev_open, > + .release = rpmsg_ctrl_dev_release, > + .unlocked_ioctl = rpmsg_ctrl_dev_ioctl, > + .compat_ioctl = compat_ptr_ioctl, > +}; > + > +static int rpmsg_ctrl_add_control(struct rpmsg_ctrl_dev *ctrldev) > +{ > + struct device *dev = &ctrldev->dev; > + int ret; > + > + cdev_init(&ctrldev->cdev, &rpmsg_ctrl_fops); > + ctrldev->cdev.owner = THIS_MODULE; > + > + ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); > + if (ret < 0) > + return ret; > + dev->devt = MKDEV(MAJOR(rpmsg_major), ret); > + > + dev_set_name(dev, "rpmsg_ctrl%d", dev->id); > + > + ret = cdev_add(&ctrldev->cdev, dev->devt, 1); > + if (ret) > + goto free_minor_ida; > + > + dev_info(dev, "add %s control for %s driver\n", > + dev_name(dev), dev_name(dev->parent)); > + > + return 0; > + > +free_minor_ida: > + ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); > + > + return ret; > +} > + > +static int rpmsg_ctrl_probe(struct rpmsg_device *rpdev) > +{ > + struct rpmsg_ctrl_dev *ctrldev; > + struct device *dev; > + int ret; > + > + ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL); > + if (!ctrldev) > + return -ENOMEM; > + > + ctrldev->rpdev = rpdev; > + > + dev = &ctrldev->dev; > + device_initialize(dev); > + dev->parent = &rpdev->dev; > + > + ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL); > + if (ret < 0) > + goto free_ctrldev; > + > + dev->id = ret; > + > + ret = rpmsg_ctrl_add_control(ctrldev); > + if (ret < 0) > + goto free_ctrl_ida; > + > + /* We can now rely on the release function for cleanup */ > + dev->release = rpmsg_ctrl_dev_release_device; > + > + ret = device_add(dev); > + if (ret) { > + dev_err(&rpdev->dev, "device_add failed: %d\n", ret); > + put_device(dev); > + goto free_ctrl_ida; > + } > + > + dev_set_drvdata(dev, ctrldev); > + dev_set_drvdata(&rpdev->dev, ctrldev); > + > + return 0; > + > +free_ctrl_ida: > + ida_simple_remove(&rpmsg_ctrl_ida, dev->id); > +free_ctrldev: > + put_device(dev); > + kfree(ctrldev); > + > + return ret; > +} > + > +static void rpmsg_ctrl_remove(struct rpmsg_device *rpdev) > +{ > + struct rpmsg_ctrl_dev *ctrldev = dev_get_drvdata(&rpdev->dev); > + > + device_del(&ctrldev->dev); > + put_device(&ctrldev->dev); > +} > + > +static struct rpmsg_driver rpmsg_ctrl_driver = { > + .drv.name = KBUILD_MODNAME, > + .probe = rpmsg_ctrl_probe, > + .remove = rpmsg_ctrl_remove, > +}; > + > +static int rpmsg_ctrl_init(void) > +{ > + int ret; > + > + ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg"); > + if (ret < 0) { > + pr_err("rpmsg_ctrl: failed to allocate char dev region\n"); > + return ret; > + } > + > + ret = register_rpmsg_driver(&rpmsg_ctrl_driver); > + if (ret < 0) { > + pr_err("rpmsg_ctrl: failed to register rpmsg driver\n"); > + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); > + } > + > + return ret; > +} > +postcore_initcall(rpmsg_ctrl_init); > + > +static void rpmsg_ctrl_exit(void) > +{ > + unregister_rpmsg_driver(&rpmsg_ctrl_driver); > + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); > +} > +module_exit(rpmsg_ctrl_exit); > + > +MODULE_DESCRIPTION("ioctl rpmsg driver"); > +MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>"); > +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME); > +MODULE_LICENSE("GPL v2"); > -- > 2.17.1 >
Hi Arnaud, On Tue, Dec 22, 2020 at 11:57:11AM +0100, Arnaud Pouliquen wrote: > The RPMsg_ctrl driver is a duplication of the ioctrl part of the > rpmsg_char driver to make generic the ioctl to manage channels by > the userspace applications. > > As a first step, this driver just creates the /dev/rpmsg_ctl<x> > ( <x> is the instance value). The ioctl is not implemented. > > Notice that this driver is associated to a RPMsg device with no endpoint. > Instantiating this device as an RPMsg device allows to retrieve the > associated RPMsg backend. > > Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> > --- > drivers/rpmsg/Kconfig | 8 ++ > drivers/rpmsg/Makefile | 1 + > drivers/rpmsg/rpmsg_ctrl.c | 208 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 217 insertions(+) > create mode 100644 drivers/rpmsg/rpmsg_ctrl.c > > diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig > index 0b4407abdf13..c9e602016c3b 100644 > --- a/drivers/rpmsg/Kconfig > +++ b/drivers/rpmsg/Kconfig > @@ -23,6 +23,14 @@ config RPMSG_NS > channel that probes the associated RPMsg device on remote endpoint > service announcement. > > +config RPMSG_CTRL > + tristate "RPMSG control interface" > + depends on RPMSG > + help > + Say Y here to enable the support of the /dev/rpmsg_ctl API. this API > + allows user-space programs to create channels with specific name, > + source and destination addresses. > + > config RPMSG_MTK_SCP > tristate "MediaTek SCP" > depends on MTK_SCP > diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile > index 8d452656f0ee..3c1bce9d0228 100644 > --- a/drivers/rpmsg/Makefile > +++ b/drivers/rpmsg/Makefile > @@ -2,6 +2,7 @@ > obj-$(CONFIG_RPMSG) += rpmsg_core.o > obj-$(CONFIG_RPMSG_CHAR) += rpmsg_char.o > obj-$(CONFIG_RPMSG_NS) += rpmsg_ns.o > +obj-$(CONFIG_RPMSG_CTRL) += rpmsg_ctrl.o > obj-$(CONFIG_RPMSG_MTK_SCP) += mtk_rpmsg.o > qcom_glink-objs := qcom_glink_native.o qcom_glink_ssr.o > obj-$(CONFIG_RPMSG_QCOM_GLINK) += qcom_glink.o > diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c > new file mode 100644 > index 000000000000..425c3e32ada4 > --- /dev/null > +++ b/drivers/rpmsg/rpmsg_ctrl.c > @@ -0,0 +1,208 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) STMicroelectronics 2020 > + */ > + > +#include <linux/cdev.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/slab.h> > +#include "rpmsg_internal.h" > +#include <uapi/linux/rpmsg.h> > + > +#define RPMSG_DEV_MAX (MINORMASK + 1) > + > +#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrl_dev, dev) > +#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrl_dev, cdev) > + > +/** > + * struct rpmsg_ctrl_dev - control device for instantiating endpoint devices > + * @rpdev: underlaying rpmsg device > + * @cdev: cdev for the ctrl device > + * @dev: device for the ctrl device > + */ > +struct rpmsg_ctrl_dev { > + struct rpmsg_device *rpdev; > + struct cdev cdev; > + struct device dev; > +}; As Bjorn pointed out it would be better modify rpmsg_char.c to what you want it to be rather than spinning off a parallel implementation. One immediate advantage would be to avoid the creation of new structures that are identical to existing ones. There's also the problem of bisecting... If I remember correctly there are a few instances where applying this set would break a bisect session. > + > +static DEFINE_IDA(rpmsg_ctrl_ida); > +static DEFINE_IDA(rpmsg_minor_ida); > + > +static dev_t rpmsg_major; > + > +static int rpmsg_ctrl_dev_open(struct inode *inode, struct file *filp) > +{ > + struct rpmsg_ctrl_dev *ctrldev = cdev_to_ctrldev(inode->i_cdev); > + > + get_device(&ctrldev->dev); > + filp->private_data = ctrldev; > + > + return 0; > +} > + > +static long rpmsg_ctrl_dev_ioctl(struct file *fp, unsigned int cmd, > + unsigned long arg) > +{ > + struct rpmsg_ctrl_dev *ctrldev = fp->private_data; > + > + dev_info(&ctrldev->dev, "Control not yet implemented\n"); > + > + return 0; > +}; > + > +static int rpmsg_ctrl_dev_release(struct inode *inode, struct file *filp) > +{ > + struct rpmsg_ctrl_dev *ctrldev = cdev_to_ctrldev(inode->i_cdev); > + > + put_device(&ctrldev->dev); > + > + return 0; > +} > + > +static void rpmsg_ctrl_dev_release_device(struct device *dev) > +{ > + struct rpmsg_ctrl_dev *ctrldev = dev_to_ctrldev(dev); > + > + dev_err(dev, "%s\n", __func__); Debug left over. > + > + ida_simple_remove(&rpmsg_ctrl_ida, dev->id); > + ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); > + cdev_del(&ctrldev->cdev); > + kfree(ctrldev); > +} > + > +static const struct file_operations rpmsg_ctrl_fops = { > + .owner = THIS_MODULE, > + .open = rpmsg_ctrl_dev_open, > + .release = rpmsg_ctrl_dev_release, > + .unlocked_ioctl = rpmsg_ctrl_dev_ioctl, > + .compat_ioctl = compat_ptr_ioctl, > +}; > + > +static int rpmsg_ctrl_add_control(struct rpmsg_ctrl_dev *ctrldev) > +{ > + struct device *dev = &ctrldev->dev; > + int ret; > + > + cdev_init(&ctrldev->cdev, &rpmsg_ctrl_fops); > + ctrldev->cdev.owner = THIS_MODULE; > + > + ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); > + if (ret < 0) > + return ret; > + dev->devt = MKDEV(MAJOR(rpmsg_major), ret); > + > + dev_set_name(dev, "rpmsg_ctrl%d", dev->id); Here "rpmsg_ctrl" is used but the changelog and refers to "rpmsg_ctl". Using the latter would, as Bjorn pointed out, break existing implementation. > + > + ret = cdev_add(&ctrldev->cdev, dev->devt, 1); > + if (ret) > + goto free_minor_ida; > + > + dev_info(dev, "add %s control for %s driver\n", > + dev_name(dev), dev_name(dev->parent)); > + > + return 0; > + > +free_minor_ida: > + ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); > + > + return ret; > +} > + > +static int rpmsg_ctrl_probe(struct rpmsg_device *rpdev) > +{ > + struct rpmsg_ctrl_dev *ctrldev; > + struct device *dev; > + int ret; > + > + ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL); > + if (!ctrldev) > + return -ENOMEM; > + > + ctrldev->rpdev = rpdev; > + > + dev = &ctrldev->dev; > + device_initialize(dev); > + dev->parent = &rpdev->dev; > + > + ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL); > + if (ret < 0) > + goto free_ctrldev; > + > + dev->id = ret; > + > + ret = rpmsg_ctrl_add_control(ctrldev); > + if (ret < 0) > + goto free_ctrl_ida; > + > + /* We can now rely on the release function for cleanup */ > + dev->release = rpmsg_ctrl_dev_release_device; > + > + ret = device_add(dev); > + if (ret) { > + dev_err(&rpdev->dev, "device_add failed: %d\n", ret); > + put_device(dev); > + goto free_ctrl_ida; > + } > + > + dev_set_drvdata(dev, ctrldev); > + dev_set_drvdata(&rpdev->dev, ctrldev); > + > + return 0; > + > +free_ctrl_ida: > + ida_simple_remove(&rpmsg_ctrl_ida, dev->id); > +free_ctrldev: > + put_device(dev); > + kfree(ctrldev); > + > + return ret; > +} > + > +static void rpmsg_ctrl_remove(struct rpmsg_device *rpdev) > +{ > + struct rpmsg_ctrl_dev *ctrldev = dev_get_drvdata(&rpdev->dev); > + > + device_del(&ctrldev->dev); > + put_device(&ctrldev->dev); > +} > + > +static struct rpmsg_driver rpmsg_ctrl_driver = { > + .drv.name = KBUILD_MODNAME, > + .probe = rpmsg_ctrl_probe, > + .remove = rpmsg_ctrl_remove, > +}; > + > +static int rpmsg_ctrl_init(void) > +{ > + int ret; > + > + ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg"); > + if (ret < 0) { > + pr_err("rpmsg_ctrl: failed to allocate char dev region\n"); > + return ret; > + } > + > + ret = register_rpmsg_driver(&rpmsg_ctrl_driver); > + if (ret < 0) { > + pr_err("rpmsg_ctrl: failed to register rpmsg driver\n"); > + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); > + } > + > + return ret; > +} > +postcore_initcall(rpmsg_ctrl_init); > + > +static void rpmsg_ctrl_exit(void) > +{ > + unregister_rpmsg_driver(&rpmsg_ctrl_driver); > + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); > +} > +module_exit(rpmsg_ctrl_exit); > + > +MODULE_DESCRIPTION("ioctl rpmsg driver"); > +MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>"); > +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME); > +MODULE_LICENSE("GPL v2"); > -- > 2.17.1 >
diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig index 0b4407abdf13..c9e602016c3b 100644 --- a/drivers/rpmsg/Kconfig +++ b/drivers/rpmsg/Kconfig @@ -23,6 +23,14 @@ config RPMSG_NS channel that probes the associated RPMsg device on remote endpoint service announcement. +config RPMSG_CTRL + tristate "RPMSG control interface" + depends on RPMSG + help + Say Y here to enable the support of the /dev/rpmsg_ctl API. this API + allows user-space programs to create channels with specific name, + source and destination addresses. + config RPMSG_MTK_SCP tristate "MediaTek SCP" depends on MTK_SCP diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile index 8d452656f0ee..3c1bce9d0228 100644 --- a/drivers/rpmsg/Makefile +++ b/drivers/rpmsg/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_RPMSG) += rpmsg_core.o obj-$(CONFIG_RPMSG_CHAR) += rpmsg_char.o obj-$(CONFIG_RPMSG_NS) += rpmsg_ns.o +obj-$(CONFIG_RPMSG_CTRL) += rpmsg_ctrl.o obj-$(CONFIG_RPMSG_MTK_SCP) += mtk_rpmsg.o qcom_glink-objs := qcom_glink_native.o qcom_glink_ssr.o obj-$(CONFIG_RPMSG_QCOM_GLINK) += qcom_glink.o diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c new file mode 100644 index 000000000000..425c3e32ada4 --- /dev/null +++ b/drivers/rpmsg/rpmsg_ctrl.c @@ -0,0 +1,208 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) STMicroelectronics 2020 + */ + +#include <linux/cdev.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include "rpmsg_internal.h" +#include <uapi/linux/rpmsg.h> + +#define RPMSG_DEV_MAX (MINORMASK + 1) + +#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrl_dev, dev) +#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrl_dev, cdev) + +/** + * struct rpmsg_ctrl_dev - control device for instantiating endpoint devices + * @rpdev: underlaying rpmsg device + * @cdev: cdev for the ctrl device + * @dev: device for the ctrl device + */ +struct rpmsg_ctrl_dev { + struct rpmsg_device *rpdev; + struct cdev cdev; + struct device dev; +}; + +static DEFINE_IDA(rpmsg_ctrl_ida); +static DEFINE_IDA(rpmsg_minor_ida); + +static dev_t rpmsg_major; + +static int rpmsg_ctrl_dev_open(struct inode *inode, struct file *filp) +{ + struct rpmsg_ctrl_dev *ctrldev = cdev_to_ctrldev(inode->i_cdev); + + get_device(&ctrldev->dev); + filp->private_data = ctrldev; + + return 0; +} + +static long rpmsg_ctrl_dev_ioctl(struct file *fp, unsigned int cmd, + unsigned long arg) +{ + struct rpmsg_ctrl_dev *ctrldev = fp->private_data; + + dev_info(&ctrldev->dev, "Control not yet implemented\n"); + + return 0; +}; + +static int rpmsg_ctrl_dev_release(struct inode *inode, struct file *filp) +{ + struct rpmsg_ctrl_dev *ctrldev = cdev_to_ctrldev(inode->i_cdev); + + put_device(&ctrldev->dev); + + return 0; +} + +static void rpmsg_ctrl_dev_release_device(struct device *dev) +{ + struct rpmsg_ctrl_dev *ctrldev = dev_to_ctrldev(dev); + + dev_err(dev, "%s\n", __func__); + + ida_simple_remove(&rpmsg_ctrl_ida, dev->id); + ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); + cdev_del(&ctrldev->cdev); + kfree(ctrldev); +} + +static const struct file_operations rpmsg_ctrl_fops = { + .owner = THIS_MODULE, + .open = rpmsg_ctrl_dev_open, + .release = rpmsg_ctrl_dev_release, + .unlocked_ioctl = rpmsg_ctrl_dev_ioctl, + .compat_ioctl = compat_ptr_ioctl, +}; + +static int rpmsg_ctrl_add_control(struct rpmsg_ctrl_dev *ctrldev) +{ + struct device *dev = &ctrldev->dev; + int ret; + + cdev_init(&ctrldev->cdev, &rpmsg_ctrl_fops); + ctrldev->cdev.owner = THIS_MODULE; + + ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); + if (ret < 0) + return ret; + dev->devt = MKDEV(MAJOR(rpmsg_major), ret); + + dev_set_name(dev, "rpmsg_ctrl%d", dev->id); + + ret = cdev_add(&ctrldev->cdev, dev->devt, 1); + if (ret) + goto free_minor_ida; + + dev_info(dev, "add %s control for %s driver\n", + dev_name(dev), dev_name(dev->parent)); + + return 0; + +free_minor_ida: + ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); + + return ret; +} + +static int rpmsg_ctrl_probe(struct rpmsg_device *rpdev) +{ + struct rpmsg_ctrl_dev *ctrldev; + struct device *dev; + int ret; + + ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL); + if (!ctrldev) + return -ENOMEM; + + ctrldev->rpdev = rpdev; + + dev = &ctrldev->dev; + device_initialize(dev); + dev->parent = &rpdev->dev; + + ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL); + if (ret < 0) + goto free_ctrldev; + + dev->id = ret; + + ret = rpmsg_ctrl_add_control(ctrldev); + if (ret < 0) + goto free_ctrl_ida; + + /* We can now rely on the release function for cleanup */ + dev->release = rpmsg_ctrl_dev_release_device; + + ret = device_add(dev); + if (ret) { + dev_err(&rpdev->dev, "device_add failed: %d\n", ret); + put_device(dev); + goto free_ctrl_ida; + } + + dev_set_drvdata(dev, ctrldev); + dev_set_drvdata(&rpdev->dev, ctrldev); + + return 0; + +free_ctrl_ida: + ida_simple_remove(&rpmsg_ctrl_ida, dev->id); +free_ctrldev: + put_device(dev); + kfree(ctrldev); + + return ret; +} + +static void rpmsg_ctrl_remove(struct rpmsg_device *rpdev) +{ + struct rpmsg_ctrl_dev *ctrldev = dev_get_drvdata(&rpdev->dev); + + device_del(&ctrldev->dev); + put_device(&ctrldev->dev); +} + +static struct rpmsg_driver rpmsg_ctrl_driver = { + .drv.name = KBUILD_MODNAME, + .probe = rpmsg_ctrl_probe, + .remove = rpmsg_ctrl_remove, +}; + +static int rpmsg_ctrl_init(void) +{ + int ret; + + ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg"); + if (ret < 0) { + pr_err("rpmsg_ctrl: failed to allocate char dev region\n"); + return ret; + } + + ret = register_rpmsg_driver(&rpmsg_ctrl_driver); + if (ret < 0) { + pr_err("rpmsg_ctrl: failed to register rpmsg driver\n"); + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); + } + + return ret; +} +postcore_initcall(rpmsg_ctrl_init); + +static void rpmsg_ctrl_exit(void) +{ + unregister_rpmsg_driver(&rpmsg_ctrl_driver); + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); +} +module_exit(rpmsg_ctrl_exit); + +MODULE_DESCRIPTION("ioctl rpmsg driver"); +MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>"); +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME); +MODULE_LICENSE("GPL v2");
The RPMsg_ctrl driver is a duplication of the ioctrl part of the rpmsg_char driver to make generic the ioctl to manage channels by the userspace applications. As a first step, this driver just creates the /dev/rpmsg_ctl<x> ( <x> is the instance value). The ioctl is not implemented. Notice that this driver is associated to a RPMsg device with no endpoint. Instantiating this device as an RPMsg device allows to retrieve the associated RPMsg backend. Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> --- drivers/rpmsg/Kconfig | 8 ++ drivers/rpmsg/Makefile | 1 + drivers/rpmsg/rpmsg_ctrl.c | 208 +++++++++++++++++++++++++++++++++++++ 3 files changed, 217 insertions(+) create mode 100644 drivers/rpmsg/rpmsg_ctrl.c