diff options
Diffstat (limited to 'drivers/media/cec/usb/rainshadow')
| -rw-r--r-- | drivers/media/cec/usb/rainshadow/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/media/cec/usb/rainshadow/Makefile | 2 | ||||
| -rw-r--r-- | drivers/media/cec/usb/rainshadow/rainshadow-cec.c | 380 |
3 files changed, 395 insertions, 0 deletions
diff --git a/drivers/media/cec/usb/rainshadow/Kconfig b/drivers/media/cec/usb/rainshadow/Kconfig new file mode 100644 index 000000000..c9ef2c192 --- /dev/null +++ b/drivers/media/cec/usb/rainshadow/Kconfig @@ -0,0 +1,13 @@ +# SPDX-License-Identifier: GPL-2.0-only +config USB_RAINSHADOW_CEC + tristate "RainShadow Tech HDMI CEC" + select CEC_CORE + select USB + select USB_ACM + select SERIO + select SERIO_SERPORT + help + This is a cec driver for the RainShadow Tech HDMI CEC device. + + To compile this driver as a module, choose M here: the + module will be called rainshadow-cec. diff --git a/drivers/media/cec/usb/rainshadow/Makefile b/drivers/media/cec/usb/rainshadow/Makefile new file mode 100644 index 000000000..47b33c574 --- /dev/null +++ b/drivers/media/cec/usb/rainshadow/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_USB_RAINSHADOW_CEC) += rainshadow-cec.o diff --git a/drivers/media/cec/usb/rainshadow/rainshadow-cec.c b/drivers/media/cec/usb/rainshadow/rainshadow-cec.c new file mode 100644 index 000000000..ee870ea1a --- /dev/null +++ b/drivers/media/cec/usb/rainshadow/rainshadow-cec.c @@ -0,0 +1,380 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * RainShadow Tech HDMI CEC driver + * + * Copyright 2016 Hans Verkuil <hverkuil@xs4all.nl + */ + +/* + * Notes: + * + * The higher level protocols are currently disabled. This can be added + * later, similar to how this is done for the Pulse Eight CEC driver. + * + * Documentation of the protocol is available here: + * + * http://rainshadowtech.com/doc/HDMICECtoUSBandRS232v2.0.pdf + */ + +#include <linux/completion.h> +#include <linux/ctype.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/serio.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/time.h> +#include <linux/workqueue.h> + +#include <media/cec.h> + +MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>"); +MODULE_DESCRIPTION("RainShadow Tech HDMI CEC driver"); +MODULE_LICENSE("GPL"); + +#define DATA_SIZE 256 + +struct rain { + struct device *dev; + struct serio *serio; + struct cec_adapter *adap; + struct completion cmd_done; + struct work_struct work; + + /* Low-level ringbuffer, collecting incoming characters */ + char buf[DATA_SIZE]; + unsigned int buf_rd_idx; + unsigned int buf_wr_idx; + unsigned int buf_len; + spinlock_t buf_lock; + + /* command buffer */ + char cmd[DATA_SIZE]; + unsigned int cmd_idx; + bool cmd_started; + + /* reply to a command, only used to store the firmware version */ + char cmd_reply[DATA_SIZE]; + + struct mutex write_lock; +}; + +static void rain_process_msg(struct rain *rain) +{ + struct cec_msg msg = {}; + const char *cmd = rain->cmd + 3; + int stat = -1; + + for (; *cmd; cmd++) { + if (!isxdigit(*cmd)) + continue; + if (isxdigit(cmd[0]) && isxdigit(cmd[1])) { + if (msg.len == CEC_MAX_MSG_SIZE) + break; + if (hex2bin(msg.msg + msg.len, cmd, 1)) + continue; + msg.len++; + cmd++; + continue; + } + if (!cmd[1]) + stat = hex_to_bin(cmd[0]); + break; + } + + if (rain->cmd[0] == 'R') { + if (stat == 1 || stat == 2) + cec_received_msg(rain->adap, &msg); + return; + } + + switch (stat) { + case 1: + cec_transmit_attempt_done(rain->adap, CEC_TX_STATUS_OK); + break; + case 2: + cec_transmit_attempt_done(rain->adap, CEC_TX_STATUS_NACK); + break; + default: + cec_transmit_attempt_done(rain->adap, CEC_TX_STATUS_LOW_DRIVE); + break; + } +} + +static void rain_irq_work_handler(struct work_struct *work) +{ + struct rain *rain = + container_of(work, struct rain, work); + + while (true) { + unsigned long flags; + char data; + + spin_lock_irqsave(&rain->buf_lock, flags); + if (!rain->buf_len) { + spin_unlock_irqrestore(&rain->buf_lock, flags); + break; + } + + data = rain->buf[rain->buf_rd_idx]; + rain->buf_len--; + rain->buf_rd_idx = (rain->buf_rd_idx + 1) & 0xff; + + spin_unlock_irqrestore(&rain->buf_lock, flags); + + if (!rain->cmd_started && data != '?') + continue; + + switch (data) { + case '\r': + rain->cmd[rain->cmd_idx] = '\0'; + dev_dbg(rain->dev, "received: %s\n", rain->cmd); + if (!memcmp(rain->cmd, "REC", 3) || + !memcmp(rain->cmd, "STA", 3)) { + rain_process_msg(rain); + } else { + strscpy(rain->cmd_reply, rain->cmd, + sizeof(rain->cmd_reply)); + complete(&rain->cmd_done); + } + rain->cmd_idx = 0; + rain->cmd_started = false; + break; + + case '\n': + rain->cmd_idx = 0; + rain->cmd_started = false; + break; + + case '?': + rain->cmd_idx = 0; + rain->cmd_started = true; + break; + + default: + if (rain->cmd_idx >= DATA_SIZE - 1) { + dev_dbg(rain->dev, + "throwing away %d bytes of garbage\n", rain->cmd_idx); + rain->cmd_idx = 0; + } + rain->cmd[rain->cmd_idx++] = data; + break; + } + } +} + +static irqreturn_t rain_interrupt(struct serio *serio, unsigned char data, + unsigned int flags) +{ + struct rain *rain = serio_get_drvdata(serio); + + if (rain->buf_len == DATA_SIZE) { + dev_warn_once(rain->dev, "buffer overflow\n"); + return IRQ_HANDLED; + } + spin_lock(&rain->buf_lock); + rain->buf_len++; + rain->buf[rain->buf_wr_idx] = data; + rain->buf_wr_idx = (rain->buf_wr_idx + 1) & 0xff; + spin_unlock(&rain->buf_lock); + schedule_work(&rain->work); + return IRQ_HANDLED; +} + +static void rain_disconnect(struct serio *serio) +{ + struct rain *rain = serio_get_drvdata(serio); + + cancel_work_sync(&rain->work); + cec_unregister_adapter(rain->adap); + dev_info(&serio->dev, "disconnected\n"); + serio_close(serio); + serio_set_drvdata(serio, NULL); + kfree(rain); +} + +static int rain_send(struct rain *rain, const char *command) +{ + int err = serio_write(rain->serio, '!'); + + dev_dbg(rain->dev, "send: %s\n", command); + while (!err && *command) + err = serio_write(rain->serio, *command++); + if (!err) + err = serio_write(rain->serio, '~'); + + return err; +} + +static int rain_send_and_wait(struct rain *rain, + const char *cmd, const char *reply) +{ + int err; + + init_completion(&rain->cmd_done); + + mutex_lock(&rain->write_lock); + err = rain_send(rain, cmd); + if (err) + goto err; + + if (!wait_for_completion_timeout(&rain->cmd_done, HZ)) { + err = -ETIMEDOUT; + goto err; + } + if (reply && strncmp(rain->cmd_reply, reply, strlen(reply))) { + dev_dbg(rain->dev, + "transmit of '%s': received '%s' instead of '%s'\n", + cmd, rain->cmd_reply, reply); + err = -EIO; + } +err: + mutex_unlock(&rain->write_lock); + return err; +} + +static int rain_setup(struct rain *rain, struct serio *serio, + struct cec_log_addrs *log_addrs, u16 *pa) +{ + int err; + + err = rain_send_and_wait(rain, "R", "REV"); + if (err) + return err; + dev_info(rain->dev, "Firmware version %s\n", rain->cmd_reply + 4); + + err = rain_send_and_wait(rain, "Q 1", "QTY"); + if (err) + return err; + err = rain_send_and_wait(rain, "c0000", "CFG"); + if (err) + return err; + return rain_send_and_wait(rain, "A F 0000", "ADR"); +} + +static int rain_cec_adap_enable(struct cec_adapter *adap, bool enable) +{ + return 0; +} + +static int rain_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr) +{ + struct rain *rain = cec_get_drvdata(adap); + u8 cmd[16]; + + if (log_addr == CEC_LOG_ADDR_INVALID) + log_addr = CEC_LOG_ADDR_UNREGISTERED; + snprintf(cmd, sizeof(cmd), "A %x", log_addr); + return rain_send_and_wait(rain, cmd, "ADR"); +} + +static int rain_cec_adap_transmit(struct cec_adapter *adap, u8 attempts, + u32 signal_free_time, struct cec_msg *msg) +{ + struct rain *rain = cec_get_drvdata(adap); + char cmd[2 * CEC_MAX_MSG_SIZE + 16]; + unsigned int i; + int err; + + if (msg->len == 1) { + snprintf(cmd, sizeof(cmd), "x%x", cec_msg_destination(msg)); + } else { + char hex[3]; + + snprintf(cmd, sizeof(cmd), "x%x %02x ", + cec_msg_destination(msg), msg->msg[1]); + for (i = 2; i < msg->len; i++) { + snprintf(hex, sizeof(hex), "%02x", msg->msg[i]); + strlcat(cmd, hex, sizeof(cmd)); + } + } + mutex_lock(&rain->write_lock); + err = rain_send(rain, cmd); + mutex_unlock(&rain->write_lock); + return err; +} + +static const struct cec_adap_ops rain_cec_adap_ops = { + .adap_enable = rain_cec_adap_enable, + .adap_log_addr = rain_cec_adap_log_addr, + .adap_transmit = rain_cec_adap_transmit, +}; + +static int rain_connect(struct serio *serio, struct serio_driver *drv) +{ + u32 caps = CEC_CAP_DEFAULTS | CEC_CAP_PHYS_ADDR | CEC_CAP_MONITOR_ALL; + struct rain *rain; + int err = -ENOMEM; + struct cec_log_addrs log_addrs = {}; + u16 pa = CEC_PHYS_ADDR_INVALID; + + rain = kzalloc(sizeof(*rain), GFP_KERNEL); + + if (!rain) + return -ENOMEM; + + rain->serio = serio; + rain->adap = cec_allocate_adapter(&rain_cec_adap_ops, rain, + dev_name(&serio->dev), caps, 1); + err = PTR_ERR_OR_ZERO(rain->adap); + if (err < 0) + goto free_device; + + rain->dev = &serio->dev; + serio_set_drvdata(serio, rain); + INIT_WORK(&rain->work, rain_irq_work_handler); + mutex_init(&rain->write_lock); + spin_lock_init(&rain->buf_lock); + + err = serio_open(serio, drv); + if (err) + goto delete_adap; + + err = rain_setup(rain, serio, &log_addrs, &pa); + if (err) + goto close_serio; + + err = cec_register_adapter(rain->adap, &serio->dev); + if (err < 0) + goto close_serio; + + rain->dev = &rain->adap->devnode.dev; + return 0; + +close_serio: + serio_close(serio); +delete_adap: + cec_delete_adapter(rain->adap); + serio_set_drvdata(serio, NULL); +free_device: + kfree(rain); + return err; +} + +static const struct serio_device_id rain_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_RAINSHADOW_CEC, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, rain_serio_ids); + +static struct serio_driver rain_drv = { + .driver = { + .name = "rainshadow-cec", + }, + .description = "RainShadow Tech HDMI CEC driver", + .id_table = rain_serio_ids, + .interrupt = rain_interrupt, + .connect = rain_connect, + .disconnect = rain_disconnect, +}; + +module_serio_driver(rain_drv); |