/*
   * Linux V4L2 radio driver for the Griffin radioSHARK USB radio receiver
   *
   * Note the radioSHARK offers the audio through a regular USB audio device,
   * this driver only handles the tuning.
   *
   * The info necessary to drive the shark was taken from the small userspace
   * shark.c program by Michael Rolig, which he kindly placed in the Public
   * Domain.
   *
   * Copyright (c) 2012 Hans de Goede <hdegoede@redhat.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/init.h>
  #include <linux/kernel.h>
  #include <linux/leds.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/usb.h>
  #include <linux/workqueue.h>
  #include <media/v4l2-device.h>
  #include <media/tea575x.h>
  
  #if defined(CONFIG_LEDS_CLASS) || \
      (defined(CONFIG_LEDS_CLASS_MODULE) && defined(CONFIG_RADIO_SHARK_MODULE))
  #define SHARK_USE_LEDS 1
  #endif
  
  /*
   * Version Information
   */
  MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
  MODULE_DESCRIPTION("Griffin radioSHARK, USB radio receiver driver");
  MODULE_LICENSE("GPL");
  
  #define SHARK_IN_EP		0x83
  #define SHARK_OUT_EP		0x05
  
  #define TEA575X_BIT_MONO	(1<<22)		/* 0 = stereo, 1 = mono */
  #define TEA575X_BIT_BAND_MASK	(3<<20)
  #define TEA575X_BIT_BAND_FM	(0<<20)
  
  #define TB_LEN 6
  #define DRV_NAME "radioshark"
  
  #define v4l2_dev_to_shark(d) container_of(d, struct shark_device, v4l2_dev)
  
  /* Note BLUE_IS_PULSE comes after NO_LEDS as it is a status bit, not a LED */
  enum { BLUE_LED, BLUE_PULSE_LED, RED_LED, NO_LEDS, BLUE_IS_PULSE };
  
  struct shark_device {
  	struct usb_device *usbdev;
  	struct v4l2_device v4l2_dev;
  	struct snd_tea575x tea;
  
  #ifdef SHARK_USE_LEDS
  	struct work_struct led_work;
  	struct led_classdev leds[NO_LEDS];
  	char led_names[NO_LEDS][32];
  	atomic_t brightness[NO_LEDS];
  	unsigned long brightness_new;
  #endif
  
  	u8 *transfer_buffer;
  	u32 last_val;
  };
  
  static atomic_t shark_instance = ATOMIC_INIT(0);
  
  static void shark_write_val(struct snd_tea575x *tea, u32 val)
  {
  	struct shark_device *shark = tea->private_data;
  	int i, res, actual_len;
  
  	/* Avoid unnecessary (slow) USB transfers */
  	if (shark->last_val == val)
  		return;
  
  	memset(shark->transfer_buffer, 0, TB_LEN);
  	shark->transfer_buffer[0] = 0xc0; /* Write shift register command */
  	for (i = 0; i < 4; i++)
  		shark->transfer_buffer[i] |= (val >> (24 - i * 8)) & 0xff;
  
  	res = usb_interrupt_msg(shark->usbdev,
  				usb_sndintpipe(shark->usbdev, SHARK_OUT_EP),
  				shark->transfer_buffer, TB_LEN,
  				&actual_len, 1000);
  	if (res >= 0)
  		shark->last_val = val;
  	else
  		v4l2_err(&shark->v4l2_dev, "set-freq error: %d
  ", res);
  }
  
  static u32 shark_read_val(struct snd_tea575x *tea)
  {
  	struct shark_device *shark = tea->private_data;
  	int i, res, actual_len;
  	u32 val = 0;
  
  	memset(shark->transfer_buffer, 0, TB_LEN);
  	shark->transfer_buffer[0] = 0x80;
  	res = usb_interrupt_msg(shark->usbdev,
  				usb_sndintpipe(shark->usbdev, SHARK_OUT_EP),
  				shark->transfer_buffer, TB_LEN,
  				&actual_len, 1000);
  	if (res < 0) {
  		v4l2_err(&shark->v4l2_dev, "request-status error: %d
  ", res);
  		return shark->last_val;
  	}
  
  	res = usb_interrupt_msg(shark->usbdev,
  				usb_rcvintpipe(shark->usbdev, SHARK_IN_EP),
  				shark->transfer_buffer, TB_LEN,
  				&actual_len, 1000);
  	if (res < 0) {
  		v4l2_err(&shark->v4l2_dev, "get-status error: %d
  ", res);
  		return shark->last_val;
  	}
  
  	for (i = 0; i < 4; i++)
  		val |= shark->transfer_buffer[i] << (24 - i * 8);
  
  	shark->last_val = val;
  
  	/*
  	 * The shark does not allow actually reading the stereo / mono pin :(
  	 * So assume that when we're tuned to an FM station and mono has not
  	 * been requested, that we're receiving stereo.
  	 */
  	if (((val & TEA575X_BIT_BAND_MASK) == TEA575X_BIT_BAND_FM) &&
  	    !(val & TEA575X_BIT_MONO))
  		shark->tea.stereo = true;
  	else
  		shark->tea.stereo = false;
  
  	return val;
  }
  
  static struct snd_tea575x_ops shark_tea_ops = {
  	.write_val = shark_write_val,
  	.read_val  = shark_read_val,
  };
  
  #ifdef SHARK_USE_LEDS
  static void shark_led_work(struct work_struct *work)
  {
  	struct shark_device *shark =
  		container_of(work, struct shark_device, led_work);
  	int i, res, brightness, actual_len;
  
  	for (i = 0; i < 3; i++) {
  		if (!test_and_clear_bit(i, &shark->brightness_new))
  			continue;
  
  		brightness = atomic_read(&shark->brightness[i]);
  		memset(shark->transfer_buffer, 0, TB_LEN);
  		if (i != RED_LED) {
  			shark->transfer_buffer[0] = 0xA0 + i;
  			shark->transfer_buffer[1] = brightness;
  		} else
  			shark->transfer_buffer[0] = brightness ? 0xA9 : 0xA8;
  		res = usb_interrupt_msg(shark->usbdev,
  					usb_sndintpipe(shark->usbdev, 0x05),
  					shark->transfer_buffer, TB_LEN,
  					&actual_len, 1000);
  		if (res < 0)
  			v4l2_err(&shark->v4l2_dev, "set LED %s error: %d
  ",
  				 shark->led_names[i], res);
  	}
  }
  
  static void shark_led_set_blue(struct led_classdev *led_cdev,
  			       enum led_brightness value)
  {
  	struct shark_device *shark =
  		container_of(led_cdev, struct shark_device, leds[BLUE_LED]);
  
  	atomic_set(&shark->brightness[BLUE_LED], value);
  	set_bit(BLUE_LED, &shark->brightness_new);
  	clear_bit(BLUE_IS_PULSE, &shark->brightness_new);
  	schedule_work(&shark->led_work);
  }
  
  static void shark_led_set_blue_pulse(struct led_classdev *led_cdev,
  				     enum led_brightness value)
  {
  	struct shark_device *shark = container_of(led_cdev,
  				struct shark_device, leds[BLUE_PULSE_LED]);
  
  	atomic_set(&shark->brightness[BLUE_PULSE_LED], 256 - value);
  	set_bit(BLUE_PULSE_LED, &shark->brightness_new);
  	set_bit(BLUE_IS_PULSE, &shark->brightness_new);
  	schedule_work(&shark->led_work);
  }
  
  static void shark_led_set_red(struct led_classdev *led_cdev,
  			      enum led_brightness value)
  {
  	struct shark_device *shark =
  		container_of(led_cdev, struct shark_device, leds[RED_LED]);
  
  	atomic_set(&shark->brightness[RED_LED], value);
  	set_bit(RED_LED, &shark->brightness_new);
  	schedule_work(&shark->led_work);
  }
  
  static const struct led_classdev shark_led_templates[NO_LEDS] = {
  	[BLUE_LED] = {
  		.name		= "%s:blue:",
  		.brightness	= LED_OFF,
  		.max_brightness = 127,
  		.brightness_set = shark_led_set_blue,
  	},
  	[BLUE_PULSE_LED] = {
  		.name		= "%s:blue-pulse:",
  		.brightness	= LED_OFF,
  		.max_brightness = 255,
  		.brightness_set = shark_led_set_blue_pulse,
  	},
  	[RED_LED] = {
  		.name		= "%s:red:",
  		.brightness	= LED_OFF,
  		.max_brightness = 1,
  		.brightness_set = shark_led_set_red,
  	},
  };
  
  static int shark_register_leds(struct shark_device *shark, struct device *dev)
  {
  	int i, retval;
  
  	atomic_set(&shark->brightness[BLUE_LED], 127);
  	INIT_WORK(&shark->led_work, shark_led_work);
  	for (i = 0; i < NO_LEDS; i++) {
  		shark->leds[i] = shark_led_templates[i];
  		snprintf(shark->led_names[i], sizeof(shark->led_names[0]),
  			 shark->leds[i].name, shark->v4l2_dev.name);
  		shark->leds[i].name = shark->led_names[i];
  		retval = led_classdev_register(dev, &shark->leds[i]);
  		if (retval) {
  			v4l2_err(&shark->v4l2_dev,
  				 "couldn't register led: %s
  ",
  				 shark->led_names[i]);
  			return retval;
  		}
  	}
  	return 0;
  }
  
  static void shark_unregister_leds(struct shark_device *shark)
  {
  	int i;
  
  	for (i = 0; i < NO_LEDS; i++)
  		led_classdev_unregister(&shark->leds[i]);
  
  	cancel_work_sync(&shark->led_work);
  }
  
  static inline void shark_resume_leds(struct shark_device *shark)
  {
  	if (test_bit(BLUE_IS_PULSE, &shark->brightness_new))
  		set_bit(BLUE_PULSE_LED, &shark->brightness_new);
  	else
  		set_bit(BLUE_LED, &shark->brightness_new);
  	set_bit(RED_LED, &shark->brightness_new);
  	schedule_work(&shark->led_work);
  }
  #else
  static int shark_register_leds(struct shark_device *shark, struct device *dev)
  {
  	v4l2_warn(&shark->v4l2_dev,
  		  "CONFIG_LEDS_CLASS not enabled, LED support disabled
  ");
  	return 0;
  }
  static inline void shark_unregister_leds(struct shark_device *shark) { }
  static inline void shark_resume_leds(struct shark_device *shark) { }
  #endif
  
  static void usb_shark_disconnect(struct usb_interface *intf)
  {
  	struct v4l2_device *v4l2_dev = usb_get_intfdata(intf);
  	struct shark_device *shark = v4l2_dev_to_shark(v4l2_dev);
  
  	mutex_lock(&shark->tea.mutex);
  	v4l2_device_disconnect(&shark->v4l2_dev);
  	snd_tea575x_exit(&shark->tea);
  	mutex_unlock(&shark->tea.mutex);
  
  	shark_unregister_leds(shark);
  
  	v4l2_device_put(&shark->v4l2_dev);
  }
  
  static void usb_shark_release(struct v4l2_device *v4l2_dev)
  {
  	struct shark_device *shark = v4l2_dev_to_shark(v4l2_dev);
  
  	v4l2_device_unregister(&shark->v4l2_dev);
  	kfree(shark->transfer_buffer);
  	kfree(shark);
  }
  
  static int usb_shark_probe(struct usb_interface *intf,
  			   const struct usb_device_id *id)
  {
  	struct shark_device *shark;
  	int retval = -ENOMEM;
  
  	shark = kzalloc(sizeof(struct shark_device), GFP_KERNEL);
  	if (!shark)
  		return retval;
  
  	shark->transfer_buffer = kmalloc(TB_LEN, GFP_KERNEL);
  	if (!shark->transfer_buffer)
  		goto err_alloc_buffer;
  
  	v4l2_device_set_name(&shark->v4l2_dev, DRV_NAME, &shark_instance);
  
  	retval = shark_register_leds(shark, &intf->dev);
  	if (retval)
  		goto err_reg_leds;
  
  	shark->v4l2_dev.release = usb_shark_release;
  	retval = v4l2_device_register(&intf->dev, &shark->v4l2_dev);
  	if (retval) {
  		v4l2_err(&shark->v4l2_dev, "couldn't register v4l2_device
  ");
  		goto err_reg_dev;
  	}
  
  	shark->usbdev = interface_to_usbdev(intf);
  	shark->tea.v4l2_dev = &shark->v4l2_dev;
  	shark->tea.private_data = shark;
  	shark->tea.radio_nr = -1;
  	shark->tea.ops = &shark_tea_ops;
  	shark->tea.cannot_mute = true;
  	shark->tea.has_am = true;
  	strlcpy(shark->tea.card, "Griffin radioSHARK",
  		sizeof(shark->tea.card));
  	usb_make_path(shark->usbdev, shark->tea.bus_info,
  		sizeof(shark->tea.bus_info));
  
  	retval = snd_tea575x_init(&shark->tea, THIS_MODULE);
  	if (retval) {
  		v4l2_err(&shark->v4l2_dev, "couldn't init tea5757
  ");
  		goto err_init_tea;
  	}
  
  	return 0;
  
  err_init_tea:
  	v4l2_device_unregister(&shark->v4l2_dev);
  err_reg_dev:
  	shark_unregister_leds(shark);
  err_reg_leds:
  	kfree(shark->transfer_buffer);
  err_alloc_buffer:
  	kfree(shark);
  
  	return retval;
  }
  
  #ifdef CONFIG_PM
  static int usb_shark_suspend(struct usb_interface *intf, pm_message_t message)
  {
  	return 0;
  }
  
  static int usb_shark_resume(struct usb_interface *intf)
  {
  	struct v4l2_device *v4l2_dev = usb_get_intfdata(intf);
  	struct shark_device *shark = v4l2_dev_to_shark(v4l2_dev);
  
  	mutex_lock(&shark->tea.mutex);
  	snd_tea575x_set_freq(&shark->tea);
  	mutex_unlock(&shark->tea.mutex);
  
  	shark_resume_leds(shark);
  
  	return 0;
  }
  #endif
  
  /* Specify the bcdDevice value, as the radioSHARK and radioSHARK2 share ids */
  static struct usb_device_id usb_shark_device_table[] = {
  	{ .match_flags = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION |
  			 USB_DEVICE_ID_MATCH_INT_CLASS,
  	  .idVendor     = 0x077d,
  	  .idProduct    = 0x627a,
  	  .bcdDevice_lo = 0x0001,
  	  .bcdDevice_hi = 0x0001,
  	  .bInterfaceClass = 3,
  	},
  	{ }
  };
  MODULE_DEVICE_TABLE(usb, usb_shark_device_table);
  
  static struct usb_driver usb_shark_driver = {
  	.name			= DRV_NAME,
  	.probe			= usb_shark_probe,
  	.disconnect		= usb_shark_disconnect,
  	.id_table		= usb_shark_device_table,
  #ifdef CONFIG_PM
  	.suspend		= usb_shark_suspend,
  	.resume			= usb_shark_resume,
  	.reset_resume		= usb_shark_resume,
  #endif
  };
  module_usb_driver(usb_shark_driver);