diff options
Diffstat (limited to 'drivers/rpmsg/vf610_rpmsg.c')
| -rw-r--r-- | drivers/rpmsg/vf610_rpmsg.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/drivers/rpmsg/vf610_rpmsg.c b/drivers/rpmsg/vf610_rpmsg.c new file mode 100644 index 000000000000..72ce28c7d13e --- /dev/null +++ b/drivers/rpmsg/vf610_rpmsg.c @@ -0,0 +1,353 @@ +/* + * Copyright (C) 2016 Toradex AG + * + * Derived from the downstream iMX7 rpmsg implementation by Freescale. + * + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/vf610_mscm.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/rpmsg.h> +#include <linux/slab.h> +#include <linux/vf610_sema4.h> +#include <linux/virtio.h> +#include <linux/virtio_config.h> +#include <linux/virtio_ids.h> +#include <linux/virtio_ring.h> + +struct vf610_rpmsg_vproc { + struct virtio_device vdev; + unsigned int vring[2]; + char *rproc_name; + struct mutex lock; + struct delayed_work rpmsg_work; + struct virtqueue *vq[2]; + int base_vq_id; + int num_of_vqs; +}; + +#define MSCM_CPU_M4 1 + +/* + * For now, allocate 256 buffers of 512 bytes for each side. each buffer + * will then have 16B for the msg header and 496B for the payload. + * This will require a total space of 256KB for the buffers themselves, and + * 3 pages for every vring (the size of the vring depends on the number of + * buffers it supports). + */ +#define RPMSG_NUM_BUFS (32) +#define RPMSG_BUF_SIZE (512) +#define RPMSG_BUFS_SPACE (RPMSG_NUM_BUFS * RPMSG_BUF_SIZE) + +/* + * The alignment between the consumer and producer parts of the vring. + * Note: this is part of the "wire" protocol. If you change this, you need + * to update your BIOS image as well + */ +#define RPMSG_VRING_ALIGN (4096) + +/* With 256 buffers, our vring will occupy 3 pages */ +#define RPMSG_RING_SIZE ((DIV_ROUND_UP(vring_size(RPMSG_NUM_BUFS / 2, \ + RPMSG_VRING_ALIGN), PAGE_SIZE)) * PAGE_SIZE) + +#define to_vf610_rpdev(vd) container_of(vd, struct vf610_rpmsg_vproc, vdev) + +struct vf610_rpmsg_vq_info { + __u16 num; /* number of entries in the virtio_ring */ + __u16 vq_id; /* a globaly unique index of this virtqueue */ + void *addr; /* address where we mapped the virtio ring */ + struct vf610_rpmsg_vproc *rpdev; +}; + +static struct vf610_sema4_mutex *rpmsg_mutex; + +static u64 vf610_rpmsg_get_features(struct virtio_device *vdev) +{ + return 1 << VIRTIO_RPMSG_F_NS; +} + +static int vf610_rpmsg_finalize_features(struct virtio_device *vdev) +{ + /* Give virtio_ring a chance to accept features */ + vring_transport_features(vdev); + + return 0; +} + +/* kick the remote processor */ +static bool vf610_rpmsg_notify(struct virtqueue *vq) +{ + struct vf610_rpmsg_vq_info *rpvq = vq->priv; + + mutex_lock(&rpvq->rpdev->lock); + + mscm_trigger_cpu2cpu_irq(rpvq->vq_id, MSCM_CPU_M4); + + mutex_unlock(&rpvq->rpdev->lock); + + return true; +} + +static void rpmsg_work_handler(struct work_struct *work) +{ + struct vf610_rpmsg_vproc *rpdev = container_of(work, + struct vf610_rpmsg_vproc, rpmsg_work.work); + + /* Process incoming buffers on all our vrings */ + vring_interrupt(0, rpdev->vq[0]); + vring_interrupt(1, rpdev->vq[1]); +} + +static irqreturn_t cpu_to_cpu_irq_handler(int irq, void *p) +{ + struct vf610_rpmsg_vproc *rpdev = (struct vf610_rpmsg_vproc *)p; + + schedule_delayed_work(&rpdev->rpmsg_work, 0); + + return IRQ_HANDLED; +} + +static struct virtqueue *rp_find_vq(struct virtio_device *vdev, + unsigned index, + void (*callback)(struct virtqueue *vq), + const char *name) +{ + struct vf610_rpmsg_vproc *rpdev = to_vf610_rpdev(vdev); + struct vf610_rpmsg_vq_info *rpvq; + struct virtqueue *vq; + int err; + + rpvq = kmalloc(sizeof(*rpvq), GFP_KERNEL); + if (!rpvq) + return ERR_PTR(-ENOMEM); + + /* ioremap'ing normal memory, so we cast away sparse's complaints */ + rpvq->addr = (__force void *) ioremap_nocache(rpdev->vring[index], + RPMSG_RING_SIZE); + if (!rpvq->addr) { + err = -ENOMEM; + goto free_rpvq; + } + + memset(rpvq->addr, 0, RPMSG_RING_SIZE); + + pr_debug("vring%d: phys 0x%x, virt 0x%x\n", index, rpdev->vring[index], + (unsigned int) rpvq->addr); + + vq = vring_new_virtqueue(index, RPMSG_NUM_BUFS, RPMSG_VRING_ALIGN, + vdev, true, rpvq->addr, vf610_rpmsg_notify, callback, + name); + if (!vq) { + pr_err("vring_new_virtqueue failed\n"); + err = -ENOMEM; + goto unmap_vring; + } + + rpdev->vq[index] = vq; + vq->priv = rpvq; + /* system-wide unique id for this virtqueue */ + rpvq->vq_id = rpdev->base_vq_id + index; + rpvq->rpdev = rpdev; + mutex_init(&rpdev->lock); + + return vq; + +unmap_vring: + /* iounmap normal memory, so make sparse happy */ + iounmap((__force void __iomem *) rpvq->addr); +free_rpvq: + kfree(rpvq); + return ERR_PTR(err); +} + +static void vf610_rpmsg_del_vqs(struct virtio_device *vdev) +{ + struct virtqueue *vq, *n; + + list_for_each_entry_safe(vq, n, &vdev->vqs, list) { + struct vf610_rpmsg_vq_info *rpvq = vq->priv; + iounmap(rpvq->addr); + vring_del_virtqueue(vq); + kfree(rpvq); + } +} + +static int vf610_rpmsg_find_vqs(struct virtio_device *vdev, unsigned nvqs, + struct virtqueue *vqs[], + vq_callback_t *callbacks[], + const char *names[]) +{ + struct vf610_rpmsg_vproc *rpdev = to_vf610_rpdev(vdev); + int i, err; + + /* we maintain two virtqueues per remote processor (for RX and TX) */ + if (nvqs != 2) + return -EINVAL; + + for (i = 0; i < nvqs; ++i) { + vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]); + if (IS_ERR(vqs[i])) { + err = PTR_ERR(vqs[i]); + goto error; + } + } + + rpdev->num_of_vqs = nvqs; + + return 0; + +error: + vf610_rpmsg_del_vqs(vdev); + return err; +} + +static void vf610_rpmsg_reset(struct virtio_device *vdev) +{ + dev_dbg(&vdev->dev, "reset !\n"); +} + +static u8 vf610_rpmsg_get_status(struct virtio_device *vdev) +{ + return 0; +} + +static void vf610_rpmsg_set_status(struct virtio_device *vdev, u8 status) +{ + dev_dbg(&vdev->dev, "%s new status: %d\n", __func__, status); +} + +static void vf610_rpmsg_vproc_release(struct device *dev) +{ + /* this handler is provided so driver core doesn't yell at us */ +} + +static struct virtio_config_ops vf610_rpmsg_config_ops = { + .get_features = vf610_rpmsg_get_features, + .finalize_features = vf610_rpmsg_finalize_features, + .find_vqs = vf610_rpmsg_find_vqs, + .del_vqs = vf610_rpmsg_del_vqs, + .reset = vf610_rpmsg_reset, + .set_status = vf610_rpmsg_set_status, + .get_status = vf610_rpmsg_get_status, +}; + +static struct vf610_rpmsg_vproc vf610_rpmsg_vprocs = { + .vdev.id.device = VIRTIO_ID_RPMSG, + .vdev.config = &vf610_rpmsg_config_ops, + .rproc_name = "vf610_m4", + .base_vq_id = 0, +}; + +static const struct of_device_id vf610_rpmsg_dt_ids[] = { + { .compatible = "fsl,vf610-rpmsg", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, vf610_rpmsg_dt_ids); + +static int vf610_rpmsg_probe(struct platform_device *pdev) +{ + int i; + int ret = 0; + struct vf610_rpmsg_vproc *rpdev = &vf610_rpmsg_vprocs; + + INIT_DELAYED_WORK(&rpdev->rpmsg_work, rpmsg_work_handler); + + rpdev->vring[0] = 0x3f070000; + rpdev->vring[1] = 0x3f074000; + + rpdev->vdev.dev.parent = &pdev->dev; + rpdev->vdev.dev.release = vf610_rpmsg_vproc_release; + + ret = register_virtio_device(&rpdev->vdev); + if (ret) { + pr_err("%s failed to register rpdev: %d\n", + __func__, ret); + return ret; + } + + for (i = 0; i < 2; i++) { + ret = mscm_request_cpu2cpu_irq(i, cpu_to_cpu_irq_handler, + (const char *)rpdev->rproc_name, rpdev); + if (ret) { + dev_err(&pdev->dev, + "Failed to register CPU2CPU interrupt\n"); + unregister_virtio_device(&rpdev->vdev); + return ret; + } + } + + return 0; +} + +static int vf610_rpmsg_remove(struct platform_device *pdev) +{ + struct vf610_rpmsg_vproc *rpdev = &vf610_rpmsg_vprocs; + int i; + + for (i = 0; i < 2; i++) + mscm_free_cpu2cpu_irq(i, NULL); + + unregister_virtio_device(&rpdev->vdev); + + return 0; +} + +static struct platform_driver vf610_rpmsg_driver = { + .driver = { + .owner = THIS_MODULE, + .name = "vf610-rpmsg", + .of_match_table = vf610_rpmsg_dt_ids, + }, + .probe = vf610_rpmsg_probe, + .remove = vf610_rpmsg_remove, +}; + +static int __init vf610_rpmsg_init(void) +{ + int ret; + + rpmsg_mutex = vf610_sema4_mutex_create(0, 0); + if (IS_ERR(rpmsg_mutex)) { + pr_err("vf610 rpmsg unable to create mutex\n"); + return PTR_ERR(rpmsg_mutex); + } + + vf610_sema4_mutex_lock(rpmsg_mutex); + + ret = platform_driver_register(&vf610_rpmsg_driver); + if (ret) + pr_err("Unable to initialize rpmsg driver\n"); + else + pr_info("vf610 rpmsg driver is registered.\n"); + + vf610_sema4_mutex_unlock(rpmsg_mutex); + + return ret; +} + +static void __exit vf610_rpmsg_exit(void) +{ + if (rpmsg_mutex) + vf610_sema4_mutex_destroy(rpmsg_mutex); + + pr_info("vf610 rpmsg driver is unregistered.\n"); + platform_driver_unregister(&vf610_rpmsg_driver); +} +module_exit(vf610_rpmsg_exit); +module_init(vf610_rpmsg_init); + +MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>"); +MODULE_DESCRIPTION("vf610 remote processor messaging virtio device"); +MODULE_LICENSE("GPL v2"); |