[media] radio-keene: add a driver for the Keene FM Transmitter

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 427 insertions, 0 deletions

diff --git a/drivers/media/radio/radio-keene.c b/drivers/media/radio/radio-keene.c
new file mode 100644
index 000000000000..55bd1d2937c8
--- /dev/null
+++ b/drivers/media/radio/radio-keene.c
@@ -0,0 +1,427 @@
+/*
+ * Copyright (c) 2012 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+/* kernel includes */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
+#include <linux/usb.h>
+#include <linux/version.h>
+#include <linux/mutex.h>
+
+/* driver and module definitions */
+MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
+MODULE_DESCRIPTION("Keene FM Transmitter driver");
+MODULE_LICENSE("GPL");
+
+/* Actually, it advertises itself as a Logitech */
+#define USB_KEENE_VENDOR 0x046d
+#define USB_KEENE_PRODUCT 0x0a0e
+
+/* Probably USB_TIMEOUT should be modified in module parameter */
+#define BUFFER_LENGTH 8
+#define USB_TIMEOUT 500
+
+/* Frequency limits in MHz */
+#define FREQ_MIN  76U
+#define FREQ_MAX 108U
+#define FREQ_MUL 16000U
+
+/* USB Device ID List */
+static struct usb_device_id usb_keene_device_table[] = {
+	{USB_DEVICE_AND_INTERFACE_INFO(USB_KEENE_VENDOR, USB_KEENE_PRODUCT,
+							USB_CLASS_HID, 0, 0) },
+	{ }						/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, usb_keene_device_table);
+
+struct keene_device {
+	struct usb_device *usbdev;
+	struct usb_interface *intf;
+	struct video_device vdev;
+	struct v4l2_device v4l2_dev;
+	struct v4l2_ctrl_handler hdl;
+	struct mutex lock;
+
+	u8 *buffer;
+	unsigned curfreq;
+	u8 tx;
+	u8 pa;
+	bool stereo;
+	bool muted;
+	bool preemph_75_us;
+};
+
+static inline struct keene_device *to_keene_dev(struct v4l2_device *v4l2_dev)
+{
+	return container_of(v4l2_dev, struct keene_device, v4l2_dev);
+}
+
+/* Set frequency (if non-0), PA, mute and turn on/off the FM transmitter. */
+static int keene_cmd_main(struct keene_device *radio, unsigned freq, bool play)
+{
+	unsigned short freq_send = freq ? (freq - 76 * 16000) / 800 : 0;
+	int ret;
+
+	radio->buffer[0] = 0x00;
+	radio->buffer[1] = 0x50;
+	radio->buffer[2] = (freq_send >> 8) & 0xff;
+	radio->buffer[3] = freq_send & 0xff;
+	radio->buffer[4] = radio->pa;
+	/* If bit 4 is set, then tune to the frequency.
+	   If bit 3 is set, then unmute; if bit 2 is set, then mute.
+	   If bit 1 is set, then enter idle mode; if bit 0 is set,
+	   then enter transit mode.
+	 */
+	radio->buffer[5] = (radio->muted ? 4 : 8) | (play ? 1 : 2) |
+							(freq ? 0x10 : 0);
+	radio->buffer[6] = 0x00;
+	radio->buffer[7] = 0x00;
+
+	ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
+		9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
+
+	if (ret < 0) {
+		dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
+		return ret;
+	}
+	if (freq)
+		radio->curfreq = freq;
+	return 0;
+}
+
+/* Set TX, stereo and preemphasis mode (50 us vs 75 us). */
+static int keene_cmd_set(struct keene_device *radio)
+{
+	int ret;
+
+	radio->buffer[0] = 0x00;
+	radio->buffer[1] = 0x51;
+	radio->buffer[2] = radio->tx;
+	/* If bit 0 is set, then transmit mono, otherwise stereo.
+	   If bit 2 is set, then enable 75 us preemphasis, otherwise
+	   it is 50 us. */
+	radio->buffer[3] = (!radio->stereo) | (radio->preemph_75_us ? 4 : 0);
+	radio->buffer[4] = 0x00;
+	radio->buffer[5] = 0x00;
+	radio->buffer[6] = 0x00;
+	radio->buffer[7] = 0x00;
+
+	ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
+		9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
+
+	if (ret < 0) {
+		dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
+		return ret;
+	}
+	return 0;
+}
+
+/* Handle unplugging the device.
+ * We call video_unregister_device in any case.
+ * The last function called in this procedure is
+ * usb_keene_device_release.
+ */
+static void usb_keene_disconnect(struct usb_interface *intf)
+{
+	struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
+
+	v4l2_device_get(&radio->v4l2_dev);
+	mutex_lock(&radio->lock);
+	usb_set_intfdata(intf, NULL);
+	video_unregister_device(&radio->vdev);
+	v4l2_device_disconnect(&radio->v4l2_dev);
+	mutex_unlock(&radio->lock);
+	v4l2_device_put(&radio->v4l2_dev);
+}
+
+static int vidioc_querycap(struct file *file, void *priv,
+					struct v4l2_capability *v)
+{
+	struct keene_device *radio = video_drvdata(file);
+
+	strlcpy(v->driver, "radio-keene", sizeof(v->driver));
+	strlcpy(v->card, "Keene FM Transmitter", sizeof(v->card));
+	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
+	v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_MODULATOR;
+	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
+	return 0;
+}
+
+static int vidioc_g_modulator(struct file *file, void *priv,
+				struct v4l2_modulator *v)
+{
+	struct keene_device *radio = video_drvdata(file);
+
+	if (v->index > 0)
+		return -EINVAL;
+
+	strlcpy(v->name, "FM", sizeof(v->name));
+	v->rangelow = FREQ_MIN * FREQ_MUL;
+	v->rangehigh = FREQ_MAX * FREQ_MUL;
+	v->txsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
+	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
+	return 0;
+}
+
+static int vidioc_s_modulator(struct file *file, void *priv,
+				struct v4l2_modulator *v)
+{
+	struct keene_device *radio = video_drvdata(file);
+
+	if (v->index > 0)
+		return -EINVAL;
+
+	radio->stereo = (v->txsubchans == V4L2_TUNER_SUB_STEREO);
+	return keene_cmd_set(radio);
+}
+
+static int vidioc_s_frequency(struct file *file, void *priv,
+				struct v4l2_frequency *f)
+{
+	struct keene_device *radio = video_drvdata(file);
+
+	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
+		return -EINVAL;
+	f->frequency = clamp(f->frequency,
+			FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
+	return keene_cmd_main(radio, f->frequency, true);
+}
+
+static int vidioc_g_frequency(struct file *file, void *priv,
+				struct v4l2_frequency *f)
+{
+	struct keene_device *radio = video_drvdata(file);
+
+	if (f->tuner != 0)
+		return -EINVAL;
+	f->type = V4L2_TUNER_RADIO;
+	f->frequency = radio->curfreq;
+	return 0;
+}
+
+static int keene_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	static const u8 db2tx[] = {
+	     /*	 -15,  -12,   -9,   -6,   -3,    0 dB */
+		0x03, 0x13, 0x02, 0x12, 0x22, 0x32,
+	     /*	   3,    6,    9,   12,   15,   18 dB */
+		0x21, 0x31, 0x20, 0x30, 0x40, 0x50
+	};
+	struct keene_device *radio =
+		container_of(ctrl->handler, struct keene_device, hdl);
+
+	switch (ctrl->id) {
+	case V4L2_CID_AUDIO_MUTE:
+		radio->muted = ctrl->val;
+		return keene_cmd_main(radio, 0, true);
+
+	case V4L2_CID_TUNE_POWER_LEVEL:
+		/* To go from dBuV to the register value we apply the
+		   following formula: */
+		radio->pa = (ctrl->val - 71) * 100 / 62;
+		return keene_cmd_main(radio, 0, true);
+
+	case V4L2_CID_TUNE_PREEMPHASIS:
+		radio->preemph_75_us = ctrl->val == V4L2_PREEMPHASIS_75_uS;
+		return keene_cmd_set(radio);
+
+	case V4L2_CID_AUDIO_COMPRESSION_GAIN:
+		radio->tx = db2tx[(ctrl->val - ctrl->minimum) / ctrl->step];
+		return keene_cmd_set(radio);
+	}
+	return -EINVAL;
+}
+
+static int vidioc_subscribe_event(struct v4l2_fh *fh,
+				struct v4l2_event_subscription *sub)
+{
+	switch (sub->type) {
+	case V4L2_EVENT_CTRL:
+		return v4l2_event_subscribe(fh, sub, 0);
+	default:
+		return -EINVAL;
+	}
+}
+
+
+/* File system interface */
+static const struct v4l2_file_operations usb_keene_fops = {
+	.owner		= THIS_MODULE,
+	.open           = v4l2_fh_open,
+	.release        = v4l2_fh_release,
+	.poll		= v4l2_ctrl_poll,
+	.unlocked_ioctl	= video_ioctl2,
+};
+
+static const struct v4l2_ctrl_ops keene_ctrl_ops = {
+	.s_ctrl = keene_s_ctrl,
+};
+
+static const struct v4l2_ioctl_ops usb_keene_ioctl_ops = {
+	.vidioc_querycap    = vidioc_querycap,
+	.vidioc_g_modulator = vidioc_g_modulator,
+	.vidioc_s_modulator = vidioc_s_modulator,
+	.vidioc_g_frequency = vidioc_g_frequency,
+	.vidioc_s_frequency = vidioc_s_frequency,
+	.vidioc_log_status = v4l2_ctrl_log_status,
+	.vidioc_subscribe_event = vidioc_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+};
+
+static void usb_keene_video_device_release(struct v4l2_device *v4l2_dev)
+{
+	struct keene_device *radio = to_keene_dev(v4l2_dev);
+
+	/* free rest memory */
+	v4l2_ctrl_handler_free(&radio->hdl);
+	kfree(radio->buffer);
+	kfree(radio);
+}
+
+/* check if the device is present and register with v4l and usb if it is */
+static int usb_keene_probe(struct usb_interface *intf,
+				const struct usb_device_id *id)
+{
+	struct usb_device *dev = interface_to_usbdev(intf);
+	struct keene_device *radio;
+	struct v4l2_ctrl_handler *hdl;
+	int retval = 0;
+
+	/*
+	 * The Keene FM transmitter USB device has the same USB ID as
+	 * the Logitech AudioHub Speaker, but it should ignore the hid.
+	 * Check if the name is that of the Keene device.
+	 * If not, then someone connected the AudioHub and we shouldn't
+	 * attempt to handle this driver.
+	 * For reference: the product name of the AudioHub is
+	 * "AudioHub Speaker".
+	 */
+	if (dev->product && strcmp(dev->product, "B-LINK USB Audio  "))
+		return -ENODEV;
+
+	radio = kzalloc(sizeof(struct keene_device), GFP_KERNEL);
+	if (radio)
+		radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
+
+	if (!radio || !radio->buffer) {
+		dev_err(&intf->dev, "kmalloc for keene_device failed\n");
+		kfree(radio);
+		retval = -ENOMEM;
+		goto err;
+	}
+
+	hdl = &radio->hdl;
+	v4l2_ctrl_handler_init(hdl, 4);
+	v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_MUTE,
+			0, 1, 1, 0);
+	v4l2_ctrl_new_std_menu(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_PREEMPHASIS,
+			V4L2_PREEMPHASIS_75_uS, 1, V4L2_PREEMPHASIS_50_uS);
+	v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_POWER_LEVEL,
+			84, 118, 1, 118);
+	v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_COMPRESSION_GAIN,
+			-15, 18, 3, 0);
+	radio->pa = 118;
+	radio->tx = 0x32;
+	radio->stereo = true;
+	radio->curfreq = 95.16 * FREQ_MUL;
+	if (hdl->error) {
+		retval = hdl->error;
+
+		v4l2_ctrl_handler_free(hdl);
+		goto err_v4l2;
+	}
+	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
+	if (retval < 0) {
+		dev_err(&intf->dev, "couldn't register v4l2_device\n");
+		goto err_v4l2;
+	}
+
+	mutex_init(&radio->lock);
+
+	radio->v4l2_dev.ctrl_handler = hdl;
+	radio->v4l2_dev.release = usb_keene_video_device_release;
+	strlcpy(radio->vdev.name, radio->v4l2_dev.name,
+		sizeof(radio->vdev.name));
+	radio->vdev.v4l2_dev = &radio->v4l2_dev;
+	radio->vdev.fops = &usb_keene_fops;
+	radio->vdev.ioctl_ops = &usb_keene_ioctl_ops;
+	radio->vdev.lock = &radio->lock;
+	radio->vdev.release = video_device_release_empty;
+
+	radio->usbdev = interface_to_usbdev(intf);
+	radio->intf = intf;
+	usb_set_intfdata(intf, &radio->v4l2_dev);
+
+	video_set_drvdata(&radio->vdev, radio);
+	set_bit(V4L2_FL_USE_FH_PRIO, &radio->vdev.flags);
+
+	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
+	if (retval < 0) {
+		dev_err(&intf->dev, "could not register video device\n");
+		goto err_vdev;
+	}
+	v4l2_ctrl_handler_setup(hdl);
+	dev_info(&intf->dev, "V4L2 device registered as %s\n",
+			video_device_node_name(&radio->vdev));
+	return 0;
+
+err_vdev:
+	v4l2_device_unregister(&radio->v4l2_dev);
+err_v4l2:
+	kfree(radio->buffer);
+	kfree(radio);
+err:
+	return retval;
+}
+
+/* USB subsystem interface */
+static struct usb_driver usb_keene_driver = {
+	.name			= "radio-keene",
+	.probe			= usb_keene_probe,
+	.disconnect		= usb_keene_disconnect,
+	.id_table		= usb_keene_device_table,
+};
+
+static int __init keene_init(void)
+{
+	int retval = usb_register(&usb_keene_driver);
+
+	if (retval)
+		pr_err(KBUILD_MODNAME
+			": usb_register failed. Error number %d\n", retval);
+
+	return retval;
+}
+
+static void __exit keene_exit(void)
+{
+	usb_deregister(&usb_keene_driver);
+}
+
+module_init(keene_init);
+module_exit(keene_exit);
+