--- /dev/null
+/*
+ * RainShadow Tech HDMI CEC driver
+ *
+ * Copyright 2016 Hans Verkuil <hverkuil@xs4all.nl
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version of 2 of the License, or (at your
+ * option) any later version. See the file COPYING in the main directory of
+ * this archive for more details.
+ */
+
+/*
+ * 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_done(rain->adap, CEC_TX_STATUS_OK,
+ 0, 0, 0, 0);
+ break;
+ case 2:
+ cec_transmit_done(rain->adap, CEC_TX_STATUS_NACK,
+ 0, 1, 0, 0);
+ break;
+ default:
+ cec_transmit_done(rain->adap, CEC_TX_STATUS_LOW_DRIVE,
+ 0, 0, 0, 1);
+ 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;
+ bool exit_loop;
+ char data;
+
+ spin_lock_irqsave(&rain->buf_lock, flags);
+ exit_loop = rain->buf_len == 0;
+ if (rain->buf_len) {
+ 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 (exit_loop)
+ break;
+
+ 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 {
+ strcpy(rain->cmd_reply, rain->cmd);
+ 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]);
+ strncat(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_TRANSMIT | CEC_CAP_LOG_ADDRS | CEC_CAP_PHYS_ADDR |
+ CEC_CAP_PASSTHROUGH | CEC_CAP_RC | 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,
+ "HDMI CEC", 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);
+
+ 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 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);
projects / karo-tx-linux.git / commitdiff