diff options
Diffstat (limited to 'drivers/rpmsg/imx_rpmsg.c')
-rw-r--r-- | drivers/rpmsg/imx_rpmsg.c | 613 |
1 files changed, 613 insertions, 0 deletions
diff --git a/drivers/rpmsg/imx_rpmsg.c b/drivers/rpmsg/imx_rpmsg.c new file mode 100644 index 000000000000..d4ee27085fe1 --- /dev/null +++ b/drivers/rpmsg/imx_rpmsg.c @@ -0,0 +1,613 @@ +/* + * Copyright (C) 2015 Freescale Semiconductor, Inc. + * Copyright 2017-2018 NXP + * + * derived from the omap-rpmsg implementation. + * + * 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/clk.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/notifier.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/rpmsg.h> +#include <linux/slab.h> +#include <linux/virtio.h> +#include <linux/virtio_config.h> +#include <linux/virtio_ids.h> +#include <linux/virtio_ring.h> +#include <linux/imx_rpmsg.h> +#include <linux/mx8_mu.h> + +enum imx_rpmsg_variants { + IMX6SX, + IMX7D, + IMX7ULP, + IMX8QXP, + IMX8QM, +}; + +struct imx_virdev { + struct virtio_device vdev; + unsigned int vring[2]; + struct virtqueue *vq[2]; + int base_vq_id; + int num_of_vqs; + struct notifier_block nb; +}; + +struct imx_rpmsg_vproc { + char *rproc_name; + struct mutex lock; + struct clk *mu_clk; + enum imx_rpmsg_variants variant; + int vdev_nums; +#define MAX_VDEV_NUMS 8 + struct imx_virdev ivdev[MAX_VDEV_NUMS]; + void __iomem *mu_base; + struct delayed_work rpmsg_work; + struct blocking_notifier_head notifier; +#define MAX_NUM 10 /* enlarge it if overflow happen */ + u32 m4_message[MAX_NUM]; + u32 in_idx; + u32 out_idx; + u32 core_id; + spinlock_t mu_lock; +}; + +/* + * 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 (512) +#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_imx_virdev(vd) container_of(vd, struct imx_virdev, vdev) +#define to_imx_rpdev(vd, id) container_of(vd, struct imx_rpmsg_vproc, ivdev[id]) + +struct imx_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 imx_rpmsg_vproc *rpdev; +}; + +static u64 imx_rpmsg_get_features(struct virtio_device *vdev) +{ + /* VIRTIO_RPMSG_F_NS has been made private */ + return 1 << 0; +} + +static int imx_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, and let it know which virtqueue to poke at */ +static bool imx_rpmsg_notify(struct virtqueue *vq) +{ + unsigned int mu_rpmsg = 0; + struct imx_rpmsg_vq_info *rpvq = vq->priv; + + mu_rpmsg = rpvq->vq_id << 16; + mutex_lock(&rpvq->rpdev->lock); + /* send the index of the triggered virtqueue as the mu payload */ + MU_SendMessage(rpvq->rpdev->mu_base, 1, mu_rpmsg); + mutex_unlock(&rpvq->rpdev->lock); + + return true; +} + +static int imx_mu_rpmsg_callback(struct notifier_block *this, + unsigned long index, void *data) +{ + u32 mu_msg = (phys_addr_t) data; + struct imx_virdev *virdev; + + virdev = container_of(this, struct imx_virdev, nb); + + pr_debug("%s mu_msg: 0x%x\n", __func__, mu_msg); + /* ignore vq indices which are clearly not for us */ + mu_msg = mu_msg >> 16; + if (mu_msg < virdev->base_vq_id || mu_msg > virdev->base_vq_id + 1) { + pr_debug("mu_msg: 0x%x is invalid\n", mu_msg); + return NOTIFY_DONE; + } + + mu_msg -= virdev->base_vq_id; + + /* + * Currently both PENDING_MSG and explicit-virtqueue-index + * messaging are supported. + * Whatever approach is taken, at this point 'mu_msg' contains + * the index of the vring which was just triggered. + */ + if (mu_msg < virdev->num_of_vqs) + vring_interrupt(mu_msg, virdev->vq[mu_msg]); + + return NOTIFY_DONE; +} + +static int imx_mu_rpmsg_register_nb(struct imx_rpmsg_vproc *rpdev, + struct notifier_block *nb) +{ + if ((rpdev == NULL) || (nb == NULL)) + return -EINVAL; + + blocking_notifier_chain_register(&(rpdev->notifier), nb); + + return 0; +} + +static int imx_mu_rpmsg_unregister_nb(struct imx_rpmsg_vproc *rpdev, + struct notifier_block *nb) +{ + if ((rpdev == NULL) || (nb == NULL)) + return -EINVAL; + + blocking_notifier_chain_unregister(&(rpdev->notifier), nb); + + return 0; +} + +static struct virtqueue *rp_find_vq(struct virtio_device *vdev, + unsigned int index, + void (*callback)(struct virtqueue *vq), + const char *name) +{ + struct imx_virdev *virdev = to_imx_virdev(vdev); + struct imx_rpmsg_vproc *rpdev = to_imx_rpdev(virdev, + virdev->base_vq_id / 2); + struct imx_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(virdev->vring[index], + RPMSG_RING_SIZE); + if (!rpvq->addr) { + err = -ENOMEM; + goto free_rpvq; + } + + memset_io(rpvq->addr, 0, RPMSG_RING_SIZE); + + pr_debug("vring%d: phys 0x%x, virt 0x%p\n", index, virdev->vring[index], + rpvq->addr); + + vq = vring_new_virtqueue(index, RPMSG_NUM_BUFS / 2, RPMSG_VRING_ALIGN, + vdev, true, rpvq->addr, imx_rpmsg_notify, callback, + name); + if (!vq) { + pr_err("vring_new_virtqueue failed\n"); + err = -ENOMEM; + goto unmap_vring; + } + + virdev->vq[index] = vq; + vq->priv = rpvq; + /* system-wide unique id for this virtqueue */ + rpvq->vq_id = virdev->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 imx_rpmsg_del_vqs(struct virtio_device *vdev) +{ + struct virtqueue *vq, *n; + struct imx_virdev *virdev = to_imx_virdev(vdev); + struct imx_rpmsg_vproc *rpdev = to_imx_rpdev(virdev, + virdev->base_vq_id / 2); + + list_for_each_entry_safe(vq, n, &vdev->vqs, list) { + struct imx_rpmsg_vq_info *rpvq = vq->priv; + + iounmap(rpvq->addr); + vring_del_virtqueue(vq); + kfree(rpvq); + } + + if (&virdev->nb) + imx_mu_rpmsg_unregister_nb(rpdev, &virdev->nb); +} + +static int imx_rpmsg_find_vqs(struct virtio_device *vdev, unsigned int nvqs, + struct virtqueue *vqs[], + vq_callback_t *callbacks[], + const char * const names[]) +{ + struct imx_virdev *virdev = to_imx_virdev(vdev); + struct imx_rpmsg_vproc *rpdev = to_imx_rpdev(virdev, + virdev->base_vq_id / 2); + 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; + } + } + + virdev->num_of_vqs = nvqs; + + virdev->nb.notifier_call = imx_mu_rpmsg_callback; + imx_mu_rpmsg_register_nb(rpdev, &virdev->nb); + + return 0; + +error: + imx_rpmsg_del_vqs(vdev); + return err; +} + +static void imx_rpmsg_reset(struct virtio_device *vdev) +{ + dev_dbg(&vdev->dev, "reset !\n"); +} + +static u8 imx_rpmsg_get_status(struct virtio_device *vdev) +{ + return 0; +} + +static void imx_rpmsg_set_status(struct virtio_device *vdev, u8 status) +{ + dev_dbg(&vdev->dev, "%s new status: %d\n", __func__, status); +} + +static void imx_rpmsg_vproc_release(struct device *dev) +{ + /* this handler is provided so driver core doesn't yell at us */ +} + +static struct virtio_config_ops imx_rpmsg_config_ops = { + .get_features = imx_rpmsg_get_features, + .finalize_features = imx_rpmsg_finalize_features, + .find_vqs = imx_rpmsg_find_vqs, + .del_vqs = imx_rpmsg_del_vqs, + .reset = imx_rpmsg_reset, + .set_status = imx_rpmsg_set_status, + .get_status = imx_rpmsg_get_status, +}; + +static struct imx_rpmsg_vproc imx_rpmsg_vprocs[] = { + { + .rproc_name = "m4", + }, + { + .rproc_name = "m4", + }, +}; + +static const struct of_device_id imx_rpmsg_dt_ids[] = { + { .compatible = "fsl,imx6sx-rpmsg", .data = (void *)IMX6SX, }, + { .compatible = "fsl,imx7d-rpmsg", .data = (void *)IMX7D, }, + { .compatible = "fsl,imx7ulp-rpmsg", .data = (void *)IMX7ULP, }, + { .compatible = "fsl,imx8qxp-rpmsg", .data = (void *)IMX8QXP, }, + { .compatible = "fsl,imx8qm-rpmsg", .data = (void *)IMX8QM, }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, imx_rpmsg_dt_ids); + +static int set_vring_phy_buf(struct platform_device *pdev, + struct imx_rpmsg_vproc *rpdev, int vdev_nums) +{ + struct resource *res; + resource_size_t size; + unsigned int start, end; + int i, ret = 0; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res) { + size = resource_size(res); + start = res->start; + end = res->start + size; + for (i = 0; i < vdev_nums; i++) { + rpdev->ivdev[i].vring[0] = start; + rpdev->ivdev[i].vring[1] = start + + 0x8000; + start += 0x10000; + if (start > end) { + pr_err("Too small memory size %x!\n", + (u32)size); + ret = -EINVAL; + break; + } + } + } else { + return -ENOMEM; + } + + return ret; +} + +static void rpmsg_work_handler(struct work_struct *work) +{ + u32 message; + unsigned long flags; + struct delayed_work *dwork = to_delayed_work(work); + struct imx_rpmsg_vproc *rpdev = container_of(dwork, + struct imx_rpmsg_vproc, rpmsg_work); + + spin_lock_irqsave(&rpdev->mu_lock, flags); + /* handle all incoming mu message */ + while (rpdev->in_idx != rpdev->out_idx) { + message = rpdev->m4_message[rpdev->out_idx % MAX_NUM]; + spin_unlock_irqrestore(&rpdev->mu_lock, flags); + + blocking_notifier_call_chain(&(rpdev->notifier), 4, + (void *)(phys_addr_t)message); + + spin_lock_irqsave(&rpdev->mu_lock, flags); + rpdev->m4_message[rpdev->out_idx % MAX_NUM] = 0; + rpdev->out_idx++; + } + spin_unlock_irqrestore(&rpdev->mu_lock, flags); +} + +static irqreturn_t imx_mu_rpmsg_isr(int irq, void *param) +{ + u32 irqs, message; + unsigned long flags; + struct imx_rpmsg_vproc *rpdev = (struct imx_rpmsg_vproc *)param; + + irqs = MU_ReadStatus(rpdev->mu_base); + + /* RPMSG */ + if (irqs & (1 << 26)) { + spin_lock_irqsave(&rpdev->mu_lock, flags); + /* get message from receive buffer */ + MU_ReceiveMsg(rpdev->mu_base, 1, &message); + rpdev->m4_message[rpdev->in_idx % MAX_NUM] = message; + rpdev->in_idx++; + /* + * Too many mu message not be handled in timely, can enlarge + * MAX_NUM + */ + if (rpdev->in_idx == rpdev->out_idx) { + spin_unlock_irqrestore(&rpdev->mu_lock, flags); + pr_err("MU overflow!\n"); + return IRQ_HANDLED; + } + spin_unlock_irqrestore(&rpdev->mu_lock, flags); + + schedule_delayed_work(&(rpdev->rpmsg_work), 0); + } + + return IRQ_HANDLED; +} + +static int imx_rpmsg_mu_init(struct imx_rpmsg_vproc *rpdev) +{ + int ret = 0; + + /* + * bit26 is used by rpmsg channels. + * bit0 of MX7ULP_MU_CR used to let m4 to know MU is ready now + */ + MU_Init(rpdev->mu_base); + if (rpdev->variant == IMX7ULP) { + MU_EnableRxFullInt(rpdev->mu_base, 1); + ret = MU_SetFn(rpdev->mu_base, 1); + } else { + MU_EnableRxFullInt(rpdev->mu_base, 1); + } + + return ret; +} +static int imx_rpmsg_probe(struct platform_device *pdev) +{ + int core_id, j, ret = 0; + u32 irq; + struct device_node *np_mu; + struct device *dev = &pdev->dev; + struct device_node *np = pdev->dev.of_node; + struct imx_rpmsg_vproc *rpdev; + + if (of_property_read_u32(np, "multi-core-id", &core_id)) + core_id = 0; + rpdev = &imx_rpmsg_vprocs[core_id]; + rpdev->core_id = core_id; + rpdev->variant = (enum imx_rpmsg_variants)of_device_get_match_data(dev); + + /* Initialize the mu unit used by rpmsg */ + if (rpdev->core_id == 1) + np_mu = of_find_compatible_node(NULL, NULL, + "fsl,imx-mu-rpmsg1"); + else + np_mu = of_find_compatible_node(NULL, NULL, "fsl,imx6sx-mu"); + if (!np_mu) { + pr_info("Cannot find MU-RPMSG entry in device tree\n"); + return -EINVAL; + } + rpdev->mu_base = of_iomap(np_mu, 0); + WARN_ON(!rpdev->mu_base); + + spin_lock_init(&rpdev->mu_lock); + + if (rpdev->variant == IMX7ULP) + irq = of_irq_get(np_mu, 1); + else + irq = of_irq_get(np_mu, 0); + + ret = request_irq(irq, imx_mu_rpmsg_isr, + IRQF_EARLY_RESUME | IRQF_SHARED, + "imx-mu-rpmsg", rpdev); + if (ret) { + pr_err("%s: register interrupt %d failed, rc %d\n", + __func__, irq, ret); + return ret; + } + + if (rpdev->variant == IMX7D || rpdev->variant == IMX8QXP + || rpdev->variant == IMX8QM) { + rpdev->mu_clk = of_clk_get(np_mu, 0); + if (IS_ERR(rpdev->mu_clk)) { + pr_err("mu clock source missing or invalid\n"); + return PTR_ERR(rpdev->mu_clk); + } + ret = clk_prepare_enable(rpdev->mu_clk); + if (ret) { + pr_err("unable to enable mu clock\n"); + return ret; + } + } else { + rpdev->mu_clk = NULL; + } + + ret = imx_rpmsg_mu_init(rpdev); + if (ret) { + pr_err("unable to initialize mu module.\n"); + return ret; + } + INIT_DELAYED_WORK(&(rpdev->rpmsg_work), rpmsg_work_handler); + BLOCKING_INIT_NOTIFIER_HEAD(&(rpdev->notifier)); + + pr_info("MU is ready for cross core communication!\n"); + + ret = of_property_read_u32(np, "vdev-nums", &rpdev->vdev_nums); + if (ret) + rpdev->vdev_nums = 1; + if (rpdev->vdev_nums > MAX_VDEV_NUMS) { + pr_err("vdev-nums exceed the max %d\n", MAX_VDEV_NUMS); + return -EINVAL; + } + + if (!strcmp(rpdev->rproc_name, "m4")) { + ret = set_vring_phy_buf(pdev, rpdev, + rpdev->vdev_nums); + if (ret) { + pr_err("No vring buffer.\n"); + return -ENOMEM; + } + } else { + pr_err("No remote m4 processor.\n"); + return -ENODEV; + } + + for (j = 0; j < rpdev->vdev_nums; j++) { + pr_debug("%s rpdev%d vdev%d: vring0 0x%x, vring1 0x%x\n", + __func__, rpdev->core_id, rpdev->vdev_nums, + rpdev->ivdev[j].vring[0], + rpdev->ivdev[j].vring[1]); + rpdev->ivdev[j].vdev.id.device = VIRTIO_ID_RPMSG; + rpdev->ivdev[j].vdev.config = &imx_rpmsg_config_ops; + rpdev->ivdev[j].vdev.dev.parent = &pdev->dev; + rpdev->ivdev[j].vdev.dev.release = imx_rpmsg_vproc_release; + rpdev->ivdev[j].base_vq_id = j * 2; + + ret = register_virtio_device(&rpdev->ivdev[j].vdev); + if (ret) { + pr_err("%s failed to register rpdev: %d\n", + __func__, ret); + return ret; + } + + } + platform_set_drvdata(pdev, rpdev); + + return ret; +} + +#ifdef CONFIG_PM_SLEEP +static int imx_rpmsg_suspend(struct device *dev) +{ + struct imx_rpmsg_vproc *rpdev = dev_get_drvdata(dev); + + clk_disable_unprepare(rpdev->mu_clk); + + return 0; +} + +static int imx_rpmsg_resume(struct device *dev) +{ + struct imx_rpmsg_vproc *rpdev = dev_get_drvdata(dev); + int ret; + + ret = clk_prepare_enable(rpdev->mu_clk); + if (ret) { + pr_err("unable to enable mu clock\n"); + return ret; + } + + return imx_rpmsg_mu_init(rpdev); +} +#endif + +static SIMPLE_DEV_PM_OPS(imx_rpmsg_pm_ops, imx_rpmsg_suspend, imx_rpmsg_resume); + +static struct platform_driver imx_rpmsg_driver = { + .driver = { + .owner = THIS_MODULE, + .name = "imx-rpmsg", + .of_match_table = imx_rpmsg_dt_ids, + .pm = &imx_rpmsg_pm_ops, + }, + .probe = imx_rpmsg_probe, +}; + +static int __init imx_rpmsg_init(void) +{ + int ret; + + ret = platform_driver_register(&imx_rpmsg_driver); + if (ret) + pr_err("Unable to initialize rpmsg driver\n"); + else + pr_info("imx rpmsg driver is registered.\n"); + + return ret; +} + +MODULE_AUTHOR("Freescale Semiconductor, Inc."); +MODULE_DESCRIPTION("iMX remote processor messaging virtio device"); +MODULE_LICENSE("GPL v2"); +subsys_initcall(imx_rpmsg_init); |