[media] media: add driver for Masterkit MA901 usb radio

This patch creates a new usb-radio driver, radio-ma901.c, that supports
Masterkit MA 901 USB FM radio devices. This device plugs into both the
USB and an analog audio input or headphones, so this thing only deals
with initialization and frequency setting.
Signed-off-by: Alexey Klimov <klimov.linux@gmail.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/radio/Kconfig

@@ -124,6 +124,18 @@ config USB_KEENE
 	  To compile this driver as a module, choose M here: the
 	  module will be called radio-keene.
 
+config USB_MA901
+	tristate "Masterkit MA901 USB FM radio support"
+	depends on USB && VIDEO_V4L2
+	---help---
+	  Say Y here if you want to connect this type of radio to your
+	  computer's USB port. Note that the audio is not digital, and
+	  you must connect the line out connector to a sound card or a
+	  set of speakers or headphones.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called radio-ma901.
+
 config RADIO_TEA5764
 	tristate "TEA5764 I2C FM radio support"
 	depends on I2C && VIDEO_V4L2

drivers/media/radio/Makefile

@@ -24,6 +24,7 @@ obj-$(CONFIG_USB_DSBR) += dsbr100.o
 obj-$(CONFIG_RADIO_SI470X) += si470x/
 obj-$(CONFIG_USB_MR800) += radio-mr800.o
 obj-$(CONFIG_USB_KEENE) += radio-keene.o
+obj-$(CONFIG_USB_MA901) += radio-ma901.o
 obj-$(CONFIG_RADIO_TEA5764) += radio-tea5764.o
 obj-$(CONFIG_RADIO_SAA7706H) += saa7706h.o
 obj-$(CONFIG_RADIO_TEF6862) += tef6862.o

drivers/media/radio/radio-ma901.c

+/*
+ * Driver for the MasterKit MA901 USB FM radio. This device plugs
+ * into the USB port and an analog audio input or headphones, so this thing
+ * only deals with initialization, frequency setting, volume.
+ *
+ * Copyright (c) 2012 Alexey Klimov <klimov.linux@gmail.com>
+ *
+ * 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
+ */
+
+#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/mutex.h>
+
+#define DRIVER_AUTHOR "Alexey Klimov <klimov.linux@gmail.com>"
+#define DRIVER_DESC "Masterkit MA901 USB FM radio driver"
+#define DRIVER_VERSION "0.0.1"
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);
+
+#define USB_MA901_VENDOR  0x16c0
+#define USB_MA901_PRODUCT 0x05df
+
+/* dev_warn macro with driver name */
+#define MA901_DRIVER_NAME "radio-ma901"
+#define ma901radio_dev_warn(dev, fmt, arg...)				\
+		dev_warn(dev, MA901_DRIVER_NAME " - " fmt, ##arg)
+
+#define ma901radio_dev_err(dev, fmt, arg...) \
+		dev_err(dev, MA901_DRIVER_NAME " - " fmt, ##arg)
+
+/* Probably USB_TIMEOUT should be modified in module parameter */
+#define BUFFER_LENGTH 8
+#define USB_TIMEOUT 500
+
+#define FREQ_MIN  87.5
+#define FREQ_MAX 108.0
+#define FREQ_MUL 16000
+
+#define MA901_VOLUME_MAX 16
+#define MA901_VOLUME_MIN 0
+
+/* Commands that device should understand
+ * List isn't full and will be updated with implementation of new functions
+ */
+#define MA901_RADIO_SET_FREQ		0x03
+#define MA901_RADIO_SET_VOLUME		0x04
+#define MA901_RADIO_SET_MONO_STEREO	0x05
+
+/* Comfortable defines for ma901radio_set_stereo */
+#define MA901_WANT_STEREO		0x50
+#define MA901_WANT_MONO			0xd0
+
+/* module parameter */
+static int radio_nr = -1;
+module_param(radio_nr, int, 0);
+MODULE_PARM_DESC(radio_nr, "Radio file number");
+
+/* Data for one (physical) device */
+struct ma901radio_device {
+	/* reference to USB and video device */
+	struct usb_device *usbdev;
+	struct usb_interface *intf;
+	struct video_device vdev;
+	struct v4l2_device v4l2_dev;
+	struct v4l2_ctrl_handler hdl;
+
+	u8 *buffer;
+	struct mutex lock;	/* buffer locking */
+	int curfreq;
+	u16 volume;
+	int stereo;
+	bool muted;
+};
+
+static inline struct ma901radio_device *to_ma901radio_dev(struct v4l2_device *v4l2_dev)
+{
+	return container_of(v4l2_dev, struct ma901radio_device, v4l2_dev);
+}
+
+/* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
+static int ma901radio_set_freq(struct ma901radio_device *radio, int freq)
+{
+	unsigned int freq_send = 0x300 + (freq >> 5) / 25;
+	int retval;
+
+	radio->buffer[0] = 0x0a;
+	radio->buffer[1] = MA901_RADIO_SET_FREQ;
+	radio->buffer[2] = ((freq_send >> 8) & 0xff) + 0x80;
+	radio->buffer[3] = freq_send & 0xff;
+	radio->buffer[4] = 0x00;
+	radio->buffer[5] = 0x00;
+	radio->buffer[6] = 0x00;
+	radio->buffer[7] = 0x00;
+
+	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
+				9, 0x21, 0x0300, 0,
+				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
+	if (retval < 0)
+		return retval;
+
+	radio->curfreq = freq;
+	return 0;
+}
+
+static int ma901radio_set_volume(struct ma901radio_device *radio, u16 vol_to_set)
+{
+	int retval;
+
+	radio->buffer[0] = 0x0a;
+	radio->buffer[1] = MA901_RADIO_SET_VOLUME;
+	radio->buffer[2] = 0xc2;
+	radio->buffer[3] = vol_to_set + 0x20;
+	radio->buffer[4] = 0x00;
+	radio->buffer[5] = 0x00;
+	radio->buffer[6] = 0x00;
+	radio->buffer[7] = 0x00;
+
+	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
+				9, 0x21, 0x0300, 0,
+				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
+	if (retval < 0)
+		return retval;
+
+	radio->volume = vol_to_set;
+	return retval;
+}
+
+static int ma901_set_stereo(struct ma901radio_device *radio, u8 stereo)
+{
+	int retval;
+
+	radio->buffer[0] = 0x0a;
+	radio->buffer[1] = MA901_RADIO_SET_MONO_STEREO;
+	radio->buffer[2] = stereo;
+	radio->buffer[3] = 0x00;
+	radio->buffer[4] = 0x00;
+	radio->buffer[5] = 0x00;
+	radio->buffer[6] = 0x00;
+	radio->buffer[7] = 0x00;
+
+	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
+				9, 0x21, 0x0300, 0,
+				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
+
+	if (retval < 0)
+		return retval;
+
+	if (stereo == MA901_WANT_STEREO)
+		radio->stereo = V4L2_TUNER_MODE_STEREO;
+	else
+		radio->stereo = V4L2_TUNER_MODE_MONO;
+
+	return retval;
+}
+
+/* Handle unplugging the device.
+ * We call video_unregister_device in any case.
+ * The last function called in this procedure is
+ * usb_ma901radio_device_release.
+ */
+static void usb_ma901radio_disconnect(struct usb_interface *intf)
+{
+	struct ma901radio_device *radio = to_ma901radio_dev(usb_get_intfdata(intf));
+
+	mutex_lock(&radio->lock);
+	video_unregister_device(&radio->vdev);
+	usb_set_intfdata(intf, NULL);
+	v4l2_device_disconnect(&radio->v4l2_dev);
+	mutex_unlock(&radio->lock);
+	v4l2_device_put(&radio->v4l2_dev);
+}
+
+/* vidioc_querycap - query device capabilities */
+static int vidioc_querycap(struct file *file, void *priv,
+					struct v4l2_capability *v)
+{
+	struct ma901radio_device *radio = video_drvdata(file);
+
+	strlcpy(v->driver, "radio-ma901", sizeof(v->driver));
+	strlcpy(v->card, "Masterkit MA901 USB FM Radio", sizeof(v->card));
+	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
+	v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
+	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
+	return 0;
+}
+
+/* vidioc_g_tuner - get tuner attributes */
+static int vidioc_g_tuner(struct file *file, void *priv,
+				struct v4l2_tuner *v)
+{
+	struct ma901radio_device *radio = video_drvdata(file);
+
+	if (v->index > 0)
+		return -EINVAL;
+
+	v->signal = 0;
+
+	/* TODO: the same words like in _probe() goes here.
+	 * When receiving of stats will be implemented then we can call
+	 * ma901radio_get_stat().
+	 * retval = ma901radio_get_stat(radio, &is_stereo, &v->signal);
+	 */
+
+	strcpy(v->name, "FM");
+	v->type = V4L2_TUNER_RADIO;
+	v->rangelow = FREQ_MIN * FREQ_MUL;
+	v->rangehigh = FREQ_MAX * FREQ_MUL;
+	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
+	/* v->rxsubchans = is_stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO; */
+	v->audmode = radio->stereo ?
+		V4L2_TUNER_MODE_STEREO : V4L2_TUNER_MODE_MONO;
+	return 0;
+}
+
+/* vidioc_s_tuner - set tuner attributes */
+static int vidioc_s_tuner(struct file *file, void *priv,
+				struct v4l2_tuner *v)
+{
+	struct ma901radio_device *radio = video_drvdata(file);
+
+	if (v->index > 0)
+		return -EINVAL;
+
+	/* mono/stereo selector */
+	switch (v->audmode) {
+	case V4L2_TUNER_MODE_MONO:
+		return ma901_set_stereo(radio, MA901_WANT_MONO);
+	default:
+		return ma901_set_stereo(radio, MA901_WANT_STEREO);
+	}
+}
+
+/* vidioc_s_frequency - set tuner radio frequency */
+static int vidioc_s_frequency(struct file *file, void *priv,
+				struct v4l2_frequency *f)
+{
+	struct ma901radio_device *radio = video_drvdata(file);
+
+	if (f->tuner != 0)
+		return -EINVAL;
+
+	return ma901radio_set_freq(radio, clamp_t(unsigned, f->frequency,
+				FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL));
+}
+
+/* vidioc_g_frequency - get tuner radio frequency */
+static int vidioc_g_frequency(struct file *file, void *priv,
+				struct v4l2_frequency *f)
+{
+	struct ma901radio_device *radio = video_drvdata(file);
+
+	if (f->tuner != 0)
+		return -EINVAL;
+	f->frequency = radio->curfreq;
+
+	return 0;
+}
+
+static int usb_ma901radio_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct ma901radio_device *radio =
+		container_of(ctrl->handler, struct ma901radio_device, hdl);
+
+	switch (ctrl->id) {
+	case V4L2_CID_AUDIO_VOLUME:     /* set volume */
+		return ma901radio_set_volume(radio, (u16)ctrl->val);
+	}
+
+	return -EINVAL;
+}
+
+/* TODO: Should we really need to implement suspend and resume functions?
+ * Radio has it's own memory and will continue playing if power is present
+ * on usb port and on resume it will start to play again based on freq, volume
+ * values in device memory.
+ */
+static int usb_ma901radio_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	return 0;
+}
+
+static int usb_ma901radio_resume(struct usb_interface *intf)
+{
+	return 0;
+}
+
+static const struct v4l2_ctrl_ops usb_ma901radio_ctrl_ops = {
+	.s_ctrl = usb_ma901radio_s_ctrl,
+};
+
+/* File system interface */
+static const struct v4l2_file_operations usb_ma901radio_fops = {
+	.owner		= THIS_MODULE,
+	.open		= v4l2_fh_open,
+	.release	= v4l2_fh_release,
+	.poll		= v4l2_ctrl_poll,
+	.unlocked_ioctl	= video_ioctl2,
+};
+
+static const struct v4l2_ioctl_ops usb_ma901radio_ioctl_ops = {
+	.vidioc_querycap    = vidioc_querycap,
+	.vidioc_g_tuner     = vidioc_g_tuner,
+	.vidioc_s_tuner     = vidioc_s_tuner,
+	.vidioc_g_frequency = vidioc_g_frequency,
+	.vidioc_s_frequency = vidioc_s_frequency,
+	.vidioc_log_status  = v4l2_ctrl_log_status,
+	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+};
+
+static void usb_ma901radio_release(struct v4l2_device *v4l2_dev)
+{
+	struct ma901radio_device *radio = to_ma901radio_dev(v4l2_dev);
+
+	v4l2_ctrl_handler_free(&radio->hdl);
+	v4l2_device_unregister(&radio->v4l2_dev);
+	kfree(radio->buffer);
+	kfree(radio);
+}
+
+/* check if the device is present and register with v4l and usb if it is */
+static int usb_ma901radio_probe(struct usb_interface *intf,
+				const struct usb_device_id *id)
+{
+	struct ma901radio_device *radio;
+	int retval = 0;
+
+	radio = kzalloc(sizeof(struct ma901radio_device), GFP_KERNEL);
+	if (!radio) {
+		dev_err(&intf->dev, "kzalloc for ma901radio_device failed\n");
+		retval = -ENOMEM;
+		goto err;
+	}
+
+	radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
+	if (!radio->buffer) {
+		dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
+		retval = -ENOMEM;
+		goto err_nobuf;
+	}
+
+	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;
+	}
+
+	v4l2_ctrl_handler_init(&radio->hdl, 1);
+
+	/* TODO:It looks like this radio doesn't have mute/unmute control
+	 * and windows program just emulate it using volume control.
+	 * Let's plan to do the same in this driver.
+	 *
+	 * v4l2_ctrl_new_std(&radio->hdl, &usb_ma901radio_ctrl_ops,
+	 *		  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
+	 */
+
+	v4l2_ctrl_new_std(&radio->hdl, &usb_ma901radio_ctrl_ops,
+			  V4L2_CID_AUDIO_VOLUME, MA901_VOLUME_MIN,
+			  MA901_VOLUME_MAX, 1, MA901_VOLUME_MAX);
+
+	if (radio->hdl.error) {
+		retval = radio->hdl.error;
+		dev_err(&intf->dev, "couldn't register control\n");
+		goto err_ctrl;
+	}
+	mutex_init(&radio->lock);
+
+	radio->v4l2_dev.ctrl_handler = &radio->hdl;
+	radio->v4l2_dev.release = usb_ma901radio_release;
+	strlcpy(radio->vdev.name, radio->v4l2_dev.name,
+		sizeof(radio->vdev.name));
+	radio->vdev.v4l2_dev = &radio->v4l2_dev;
+	radio->vdev.fops = &usb_ma901radio_fops;
+	radio->vdev.ioctl_ops = &usb_ma901radio_ioctl_ops;
+	radio->vdev.release = video_device_release_empty;
+	radio->vdev.lock = &radio->lock;
+	set_bit(V4L2_FL_USE_FH_PRIO, &radio->vdev.flags);
+
+	radio->usbdev = interface_to_usbdev(intf);
+	radio->intf = intf;
+	usb_set_intfdata(intf, &radio->v4l2_dev);
+	radio->curfreq = 95.21 * FREQ_MUL;
+
+	video_set_drvdata(&radio->vdev, radio);
+
+	/* TODO: we can get some statistics (freq, volume) from device
+	 * but it's not implemented yet. After insertion in usb-port radio
+	 * setups frequency and starts playing without any initialization.
+	 * So we don't call usb_ma901radio_init/get_stat() here.
+	 * retval = usb_ma901radio_init(radio);
+	 */
+
+	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO,
+					radio_nr);
+	if (retval < 0) {
+		dev_err(&intf->dev, "could not register video device\n");
+		goto err_vdev;
+	}
+
+	return 0;
+
+err_vdev:
+	v4l2_ctrl_handler_free(&radio->hdl);
+err_ctrl:
+	v4l2_device_unregister(&radio->v4l2_dev);
+err_v4l2:
+	kfree(radio->buffer);
+err_nobuf:
+	kfree(radio);
+err:
+	return retval;
+}
+
+/* USB Device ID List */
+static struct usb_device_id usb_ma901radio_device_table[] = {
+	{ USB_DEVICE_AND_INTERFACE_INFO(USB_MA901_VENDOR, USB_MA901_PRODUCT,
+							USB_CLASS_HID, 0, 0) },
+	{ }						/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, usb_ma901radio_device_table);
+
+/* USB subsystem interface */
+static struct usb_driver usb_ma901radio_driver = {
+	.name			= MA901_DRIVER_NAME,
+	.probe			= usb_ma901radio_probe,
+	.disconnect		= usb_ma901radio_disconnect,
+	.suspend		= usb_ma901radio_suspend,
+	.resume			= usb_ma901radio_resume,
+	.reset_resume		= usb_ma901radio_resume,
+	.id_table		= usb_ma901radio_device_table,
+};
+
+module_usb_driver(usb_ma901radio_driver);