[PATCHv2 0/2] Add support for the RainShadow Tech HDMI CEC adapter

[PATCHv2 0/2] Add support for the RainShadow Tech HDMI CEC adapter

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

This patch series adds support to the RainShadow Tech HDMI CEC adapter
(http://rainshadowtech.com/HdmiCecUsb.html).

The first patch adds the needed serio ID, the second adds the driver itself.

Dmitry, will you take the first patch, or can we take it together with the
second patch?

This is for 4.12.

Regards,

        Hans

Changes since v1:

Implemented almost all of Dmitry's suggestions:  
        - use dev_dbg instead of 'if (debug) dev_info()'
        - reworked the interrupt/workqueue handling
        - use switch instead of 'if .. else if ...'

Hans Verkuil (2):
  serio.h: add SERIO_RAINSHADOW_CEC ID
  rainshadow-cec: new RainShadow Tech HDMI CEC driver

 MAINTAINERS                                       |   7 +
 drivers/media/usb/Kconfig                         |   1 +
 drivers/media/usb/Makefile                        |   1 +
 drivers/media/usb/rainshadow-cec/Kconfig          |  10 +
 drivers/media/usb/rainshadow-cec/Makefile         |   1 +
 drivers/media/usb/rainshadow-cec/rainshadow-cec.c | 388 ++++++++++++++++++++++
 include/uapi/linux/serio.h                        |   1 +
 7 files changed, 409 insertions(+)
 create mode 100644 drivers/media/usb/rainshadow-cec/Kconfig
 create mode 100644 drivers/media/usb/rainshadow-cec/Makefile
 create mode 100644 drivers/media/usb/rainshadow-cec/rainshadow-cec.c

-- 
2.10.2

[PATCHv2 1/2] serio.h: add SERIO_RAINSHADOW_CEC ID

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add a new serio ID for the RainShadow Tech USB HDMI CEC adapter.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 include/uapi/linux/serio.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/serio.h b/include/uapi/linux/serio.h
index f2447a8..f42e919 100644
--- a/include/uapi/linux/serio.h
+++ b/include/uapi/linux/serio.h
@@ -79,5 +79,6 @@
 #define SERIO_WACOM_IV	0x3e
 #define SERIO_EGALAX	0x3f
 #define SERIO_PULSE8_CEC	0x40
+#define SERIO_RAINSHADOW_CEC	0x41
 
 #endif /* _UAPI_SERIO_H */
-- 
2.10.2

[PATCHv2 2/2] rainshadow-cec: new RainShadow Tech HDMI CEC driver

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

This driver supports the RainShadow Tech USB HDMI CEC adapter.

See: http://rainshadowtech.com/HdmiCecUsb.html

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 MAINTAINERS                                       |   7 +
 drivers/media/usb/Kconfig                         |   1 +
 drivers/media/usb/Makefile                        |   1 +
 drivers/media/usb/rainshadow-cec/Kconfig          |  10 +
 drivers/media/usb/rainshadow-cec/Makefile         |   1 +
 drivers/media/usb/rainshadow-cec/rainshadow-cec.c | 388 ++++++++++++++++++++++
 6 files changed, 408 insertions(+)
 create mode 100644 drivers/media/usb/rainshadow-cec/Kconfig
 create mode 100644 drivers/media/usb/rainshadow-cec/Makefile
 create mode 100644 drivers/media/usb/rainshadow-cec/rainshadow-cec.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 421adff..4e479eb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10257,6 +10257,13 @@ L:	linux-fbdev@vger.kernel.org
 S:	Maintained
 F:	drivers/video/fbdev/aty/aty128fb.c
 
+RAINSHADOW-CEC DRIVER
+M:	Hans Verkuil <hverkuil@xs4all.nl>
+L:	linux-media@vger.kernel.org
+T:	git git://linuxtv.org/media_tree.git
+S:	Maintained
+F:	drivers/media/usb/rainshadow-cec/*
+
 RALINK MIPS ARCHITECTURE
 M:	John Crispin <john@phrozen.org>
 L:	linux-mips@linux-mips.org
diff --git a/drivers/media/usb/Kconfig b/drivers/media/usb/Kconfig
index c9644b6..b24e753 100644
--- a/drivers/media/usb/Kconfig
+++ b/drivers/media/usb/Kconfig
@@ -63,6 +63,7 @@ endif
 if MEDIA_CEC_SUPPORT
 	comment "USB HDMI CEC adapters"
 source "drivers/media/usb/pulse8-cec/Kconfig"
+source "drivers/media/usb/rainshadow-cec/Kconfig"
 endif
 
 endif #MEDIA_USB_SUPPORT
diff --git a/drivers/media/usb/Makefile b/drivers/media/usb/Makefile
index 0f15e33..738b993 100644
--- a/drivers/media/usb/Makefile
+++ b/drivers/media/usb/Makefile
@@ -25,3 +25,4 @@ obj-$(CONFIG_VIDEO_USBTV) += usbtv/
 obj-$(CONFIG_VIDEO_GO7007) += go7007/
 obj-$(CONFIG_DVB_AS102) += as102/
 obj-$(CONFIG_USB_PULSE8_CEC) += pulse8-cec/
+obj-$(CONFIG_USB_RAINSHADOW_CEC) += rainshadow-cec/
diff --git a/drivers/media/usb/rainshadow-cec/Kconfig b/drivers/media/usb/rainshadow-cec/Kconfig
new file mode 100644
index 0000000..447291b
--- /dev/null
+++ b/drivers/media/usb/rainshadow-cec/Kconfig
@@ -0,0 +1,10 @@
+config USB_RAINSHADOW_CEC
+	tristate "RainShadow Tech HDMI CEC"
+	depends on USB_ACM && MEDIA_CEC_SUPPORT
+	select SERIO
+	select SERIO_SERPORT
+	---help---
+	  This is a cec driver for the RainShadow Tech HDMI CEC device.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rainshadow-cec.
diff --git a/drivers/media/usb/rainshadow-cec/Makefile b/drivers/media/usb/rainshadow-cec/Makefile
new file mode 100644
index 0000000..a79fbc7
--- /dev/null
+++ b/drivers/media/usb/rainshadow-cec/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_USB_RAINSHADOW_CEC) += rainshadow-cec.o
diff --git a/drivers/media/usb/rainshadow-cec/rainshadow-cec.c b/drivers/media/usb/rainshadow-cec/rainshadow-cec.c
new file mode 100644
index 0000000..f7fc86f
--- /dev/null
+++ b/drivers/media/usb/rainshadow-cec/rainshadow-cec.c
@@ -0,0 +1,388 @@
+/*
+ * 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 = adap->priv;
+	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 = adap->priv;
+	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);
-- 
2.10.2

Re: [PATCHv2 1/2] serio.h: add SERIO_RAINSHADOW_CEC ID

[Hans Verkuil]

Dmitry,

Can I have your Ack for this patch? I'd like to get this driver in for 4.12.

You can also take this for 4.12 yourself, but serio.h doesn't change often
so the chance of conflicts is small.

Regards,

	Hans

On 03/02/17 16:26, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
>
> Add a new serio ID for the RainShadow Tech USB HDMI CEC adapter.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  include/uapi/linux/serio.h | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/include/uapi/linux/serio.h b/include/uapi/linux/serio.h
> index f2447a8..f42e919 100644
> --- a/include/uapi/linux/serio.h
> +++ b/include/uapi/linux/serio.h
> @@ -79,5 +79,6 @@
>  #define SERIO_WACOM_IV	0x3e
>  #define SERIO_EGALAX	0x3f
>  #define SERIO_PULSE8_CEC	0x40
> +#define SERIO_RAINSHADOW_CEC	0x41
>
>  #endif /* _UAPI_SERIO_H */
>

Re: [PATCHv2 1/2] serio.h: add SERIO_RAINSHADOW_CEC ID

[Hans Verkuil]

Ping?

	Hans

On 06/03/17 15:31, Hans Verkuil wrote:
> Dmitry,
> 
> Can I have your Ack for this patch? I'd like to get this driver in for 4.12.
> 
> You can also take this for 4.12 yourself, but serio.h doesn't change often
> so the chance of conflicts is small.
> 
> Regards,
> 
>     Hans
> 
> On 03/02/17 16:26, Hans Verkuil wrote:
>> From: Hans Verkuil <hans.verkuil@cisco.com>
>>
>> Add a new serio ID for the RainShadow Tech USB HDMI CEC adapter.
>>
>> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
>> ---
>>  include/uapi/linux/serio.h | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/include/uapi/linux/serio.h b/include/uapi/linux/serio.h
>> index f2447a8..f42e919 100644
>> --- a/include/uapi/linux/serio.h
>> +++ b/include/uapi/linux/serio.h
>> @@ -79,5 +79,6 @@
>>  #define SERIO_WACOM_IV    0x3e
>>  #define SERIO_EGALAX    0x3f
>>  #define SERIO_PULSE8_CEC    0x40
>> +#define SERIO_RAINSHADOW_CEC    0x41
>>
>>  #endif /* _UAPI_SERIO_H */
>>
> 

Re: [PATCHv2 1/2] serio.h: add SERIO_RAINSHADOW_CEC ID

[Dmitry Torokhov]

On Fri, Feb 03, 2017 at 04:26:32PM +0100, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Add a new serio ID for the RainShadow Tech USB HDMI CEC adapter.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

> ---
>  include/uapi/linux/serio.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/uapi/linux/serio.h b/include/uapi/linux/serio.h
> index f2447a8..f42e919 100644
> --- a/include/uapi/linux/serio.h
> +++ b/include/uapi/linux/serio.h
> @@ -79,5 +79,6 @@
>  #define SERIO_WACOM_IV	0x3e
>  #define SERIO_EGALAX	0x3f
>  #define SERIO_PULSE8_CEC	0x40
> +#define SERIO_RAINSHADOW_CEC	0x41
>  
>  #endif /* _UAPI_SERIO_H */
> -- 
> 2.10.2
> 

-- 
Dmitry