diff options
Diffstat (limited to 'drivers/rpmsg/imx_rpmsg_tty.c')
| -rw-r--r-- | drivers/rpmsg/imx_rpmsg_tty.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/drivers/rpmsg/imx_rpmsg_tty.c b/drivers/rpmsg/imx_rpmsg_tty.c new file mode 100644 index 000000000000..14904c7d517e --- /dev/null +++ b/drivers/rpmsg/imx_rpmsg_tty.c @@ -0,0 +1,233 @@ +/* + * Copyright (C) 2015 Freescale Semiconductor, Inc. + * + * derived from the omap-rpmsg implementation. + * Remote processor messaging transport - tty driver + * + * 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/kernel.h> +#include <linux/module.h> +#include <linux/rpmsg.h> +#include <linux/tty.h> +#include <linux/tty_driver.h> +#include <linux/tty_flip.h> +#include <linux/virtio.h> + +/* + * struct rpmsgtty_port - Wrapper struct for imx rpmsg tty port. + * @port: TTY port data + */ +struct rpmsgtty_port { + struct tty_port port; + spinlock_t rx_lock; + struct rpmsg_channel *rpdev; +}; + +static struct rpmsgtty_port rpmsg_tty_port; + +#define RPMSG_MAX_SIZE (512 - sizeof(struct rpmsg_hdr)) +#define MSG "hello world!" + +static void rpmsg_tty_cb(struct rpmsg_channel *rpdev, void *data, int len, + void *priv, u32 src) +{ + int space; + unsigned char *cbuf; + struct rpmsgtty_port *cport = &rpmsg_tty_port; + + /* flush the recv-ed none-zero data to tty node */ + if (len == 0) + return; + + dev_dbg(&rpdev->dev, "msg(<- src 0x%x) len %d\n", src, len); + + print_hex_dump(KERN_DEBUG, __func__, DUMP_PREFIX_NONE, 16, 1, + data, len, true); + + spin_lock_bh(&cport->rx_lock); + space = tty_prepare_flip_string(&cport->port, &cbuf, len); + if (space <= 0) { + dev_err(&rpdev->dev, "No memory for tty_prepare_flip_string\n"); + spin_unlock_bh(&cport->rx_lock); + return; + } + + memcpy(cbuf, data, len); + tty_flip_buffer_push(&cport->port); + spin_unlock_bh(&cport->rx_lock); +} + +static struct tty_port_operations rpmsgtty_port_ops = { }; + +static int rpmsgtty_install(struct tty_driver *driver, struct tty_struct *tty) +{ + return tty_port_install(&rpmsg_tty_port.port, driver, tty); +} + +static int rpmsgtty_open(struct tty_struct *tty, struct file *filp) +{ + return tty_port_open(tty->port, tty, filp); +} + +static void rpmsgtty_close(struct tty_struct *tty, struct file *filp) +{ + return tty_port_close(tty->port, tty, filp); +} + +static int rpmsgtty_write(struct tty_struct *tty, const unsigned char *buf, + int total) +{ + int count, ret = 0; + const unsigned char *tbuf; + struct rpmsgtty_port *rptty_port = container_of(tty->port, + struct rpmsgtty_port, port); + struct rpmsg_channel *rpdev = rptty_port->rpdev; + + if (NULL == buf) { + pr_err("buf shouldn't be null.\n"); + return -ENOMEM; + } + + count = total; + tbuf = buf; + do { + /* send a message to our remote processor */ + ret = rpmsg_send(rpdev, (void *)tbuf, + count > RPMSG_MAX_SIZE ? RPMSG_MAX_SIZE : count); + if (ret) { + dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret); + return ret; + } + + if (count > RPMSG_MAX_SIZE) { + count -= RPMSG_MAX_SIZE; + tbuf += RPMSG_MAX_SIZE; + } else { + count = 0; + } + } while (count > 0); + + return total; +} + +static int rpmsgtty_write_room(struct tty_struct *tty) +{ + /* report the space in the rpmsg buffer */ + return RPMSG_MAX_SIZE; +} + +static const struct tty_operations imxrpmsgtty_ops = { + .install = rpmsgtty_install, + .open = rpmsgtty_open, + .close = rpmsgtty_close, + .write = rpmsgtty_write, + .write_room = rpmsgtty_write_room, +}; + +static struct tty_driver *rpmsgtty_driver; + +static int rpmsg_tty_probe(struct rpmsg_channel *rpdev) +{ + int err; + struct rpmsgtty_port *cport = &rpmsg_tty_port; + + dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n", + rpdev->src, rpdev->dst); + + /* + * send a message to our remote processor, and tell remote + * processor about this channel + */ + err = rpmsg_send(rpdev, MSG, strlen(MSG)); + if (err) { + dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", err); + return err; + } + + rpmsgtty_driver = tty_alloc_driver(1, TTY_DRIVER_UNNUMBERED_NODE); + if (IS_ERR(rpmsgtty_driver)) + return PTR_ERR(rpmsgtty_driver); + + rpmsgtty_driver->driver_name = "rpmsg_tty"; + rpmsgtty_driver->name = "ttyRPMSG"; + rpmsgtty_driver->major = TTYAUX_MAJOR; + rpmsgtty_driver->minor_start = 3; + rpmsgtty_driver->type = TTY_DRIVER_TYPE_CONSOLE; + rpmsgtty_driver->init_termios = tty_std_termios; + + tty_set_operations(rpmsgtty_driver, &imxrpmsgtty_ops); + + tty_port_init(&cport->port); + cport->port.ops = &rpmsgtty_port_ops; + spin_lock_init(&cport->rx_lock); + cport->port.low_latency = cport->port.flags | ASYNC_LOW_LATENCY; + + err = tty_register_driver(rpmsgtty_driver); + if (err < 0) { + pr_err("Couldn't install rpmsg tty driver: err %d\n", err); + goto error; + } else + pr_info("Install rpmsg tty driver!\n"); + cport->rpdev = rpdev; + + return 0; + +error: + tty_unregister_driver(rpmsgtty_driver); + put_tty_driver(rpmsgtty_driver); + tty_port_destroy(&cport->port); + rpmsgtty_driver = NULL; + + return err; +} + +static void rpmsg_tty_remove(struct rpmsg_channel *rpdev) +{ + struct rpmsgtty_port *cport = &rpmsg_tty_port; + + dev_info(&rpdev->dev, "rpmsg tty driver is removed\n"); + + tty_unregister_driver(rpmsgtty_driver); + put_tty_driver(rpmsgtty_driver); + tty_port_destroy(&cport->port); + rpmsgtty_driver = NULL; +} + +static struct rpmsg_device_id rpmsg_driver_tty_id_table[] = { + { .name = "rpmsg-openamp-demo-channel" }, + { }, +}; +MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_tty_id_table); + +static struct rpmsg_driver rpmsg_tty_driver = { + .drv.name = KBUILD_MODNAME, + .drv.owner = THIS_MODULE, + .id_table = rpmsg_driver_tty_id_table, + .probe = rpmsg_tty_probe, + .callback = rpmsg_tty_cb, + .remove = rpmsg_tty_remove, +}; + +static int __init init(void) +{ + return register_rpmsg_driver(&rpmsg_tty_driver); +} + +static void __exit fini(void) +{ + unregister_rpmsg_driver(&rpmsg_tty_driver); +} +module_init(init); +module_exit(fini); + +MODULE_AUTHOR("Freescale Semiconductor, Inc."); +MODULE_DESCRIPTION("iMX virtio remote processor messaging tty driver"); +MODULE_LICENSE("GPL v2"); |