/* SF16-FMR2 and SF16-FMD2 radio driver for Linux
   * Copyright (c) 2011 Ondrej Zary
   *
   * Original driver was (c) 2000-2002 Ziglio Frediano, freddy77@angelfire.com
   * but almost nothing remained here after conversion to generic TEA575x
   * implementation
   */
  
  #include <linux/delay.h>
  #include <linux/module.h>	/* Modules 			*/
  #include <linux/init.h>		/* Initdata			*/
  #include <linux/slab.h>
  #include <linux/ioport.h>	/* request_region		*/
  #include <linux/io.h>		/* outb, outb_p			*/
  #include <linux/isa.h>
  #include <linux/pnp.h>
  #include <media/tea575x.h>
  
  MODULE_AUTHOR("Ondrej Zary");
  MODULE_DESCRIPTION("MediaForte SF16-FMR2 and SF16-FMD2 FM radio card driver");
  MODULE_LICENSE("GPL");
  
  /* these cards can only use two different ports (0x384 and 0x284) */
  #define FMR2_MAX 2
  
  static int radio_nr[FMR2_MAX] = { [0 ... (FMR2_MAX - 1)] = -1 };
  module_param_array(radio_nr, int, NULL, 0444);
  MODULE_PARM_DESC(radio_nr, "Radio device numbers");
  
  struct fmr2 {
  	int io;
  	struct v4l2_device v4l2_dev;
  	struct snd_tea575x tea;
  	struct v4l2_ctrl *volume;
  	struct v4l2_ctrl *balance;
  	bool is_fmd2;
  };
  
  static int num_fmr2_cards;
  static struct fmr2 *fmr2_cards[FMR2_MAX];
  static bool isa_registered;
  static bool pnp_registered;
  
  /* the port is hardwired on SF16-FMR2 */
  #define FMR2_PORT	0x384
  
  /* TEA575x tuner pins */
  #define STR_DATA	(1 << 0)
  #define STR_CLK		(1 << 1)
  #define STR_WREN	(1 << 2)
  #define STR_MOST	(1 << 3)
  /* PT2254A/TC9154A volume control pins */
  #define PT_ST		(1 << 4)
  #define PT_CK		(1 << 5)
  #define PT_DATA		(1 << 6)
  /* volume control presence pin */
  #define FMR2_HASVOL	(1 << 7)
  
  static void fmr2_tea575x_set_pins(struct snd_tea575x *tea, u8 pins)
  {
  	struct fmr2 *fmr2 = tea->private_data;
  	u8 bits = 0;
  
  	bits |= (pins & TEA575X_DATA) ? STR_DATA : 0;
  	bits |= (pins & TEA575X_CLK)  ? STR_CLK  : 0;
  	/* WRITE_ENABLE is inverted, DATA must be high during read */
  	bits |= (pins & TEA575X_WREN) ? 0 : STR_WREN | STR_DATA;
  
  	outb(bits, fmr2->io);
  }
  
  static u8 fmr2_tea575x_get_pins(struct snd_tea575x *tea)
  {
  	struct fmr2 *fmr2 = tea->private_data;
  	u8 bits = inb(fmr2->io);
  
  	return  ((bits & STR_DATA) ? TEA575X_DATA : 0) |
  		((bits & STR_MOST) ? TEA575X_MOST : 0);
  }
  
  static void fmr2_tea575x_set_direction(struct snd_tea575x *tea, bool output)
  {
  }
  
  static struct snd_tea575x_ops fmr2_tea_ops = {
  	.set_pins = fmr2_tea575x_set_pins,
  	.get_pins = fmr2_tea575x_get_pins,
  	.set_direction = fmr2_tea575x_set_direction,
  };
  
  /* TC9154A/PT2254A volume control */
  
  /* 18-bit shift register bit definitions */
  #define TC9154A_ATT_MAJ_0DB	(1 << 0)
  #define TC9154A_ATT_MAJ_10DB	(1 << 1)
  #define TC9154A_ATT_MAJ_20DB	(1 << 2)
  #define TC9154A_ATT_MAJ_30DB	(1 << 3)
  #define TC9154A_ATT_MAJ_40DB	(1 << 4)
  #define TC9154A_ATT_MAJ_50DB	(1 << 5)
  #define TC9154A_ATT_MAJ_60DB	(1 << 6)
  
  #define TC9154A_ATT_MIN_0DB	(1 << 7)
  #define TC9154A_ATT_MIN_2DB	(1 << 8)
  #define TC9154A_ATT_MIN_4DB	(1 << 9)
  #define TC9154A_ATT_MIN_6DB	(1 << 10)
  #define TC9154A_ATT_MIN_8DB	(1 << 11)
  /* bit 12 is ignored */
  #define TC9154A_CHANNEL_LEFT	(1 << 13)
  #define TC9154A_CHANNEL_RIGHT	(1 << 14)
  /* bits 15, 16, 17 must be 0 */
  
  #define	TC9154A_ATT_MAJ(x)	(1 << x)
  #define TC9154A_ATT_MIN(x)	(1 << (7 + x))
  
  static void tc9154a_set_pins(struct fmr2 *fmr2, u8 pins)
  {
  	if (!fmr2->tea.mute)
  		pins |= STR_WREN;
  
  	outb(pins, fmr2->io);
  }
  
  static void tc9154a_set_attenuation(struct fmr2 *fmr2, int att, u32 channel)
  {
  	int i;
  	u32 reg;
  	u8 bit;
  
  	reg = TC9154A_ATT_MAJ(att / 10) | TC9154A_ATT_MIN((att % 10) / 2);
  	reg |= channel;
  	/* write 18-bit shift register, LSB first */
  	for (i = 0; i < 18; i++) {
  		bit = reg & (1 << i) ? PT_DATA : 0;
  		tc9154a_set_pins(fmr2, bit);
  		udelay(5);
  		tc9154a_set_pins(fmr2, bit | PT_CK);
  		udelay(5);
  		tc9154a_set_pins(fmr2, bit);
  	}
  
  	/* latch register data */
  	udelay(5);
  	tc9154a_set_pins(fmr2, PT_ST);
  	udelay(5);
  	tc9154a_set_pins(fmr2, 0);
  }
  
  static int fmr2_s_ctrl(struct v4l2_ctrl *ctrl)
  {
  	struct snd_tea575x *tea = container_of(ctrl->handler, struct snd_tea575x, ctrl_handler);
  	struct fmr2 *fmr2 = tea->private_data;
  	int volume, balance, left, right;
  
  	switch (ctrl->id) {
  	case V4L2_CID_AUDIO_VOLUME:
  		volume = ctrl->val;
  		balance = fmr2->balance->cur.val;
  		break;
  	case V4L2_CID_AUDIO_BALANCE:
  		balance = ctrl->val;
  		volume = fmr2->volume->cur.val;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	left = right = volume;
  	if (balance < 0)
  		right = max(0, right + balance);
  	if (balance > 0)
  		left = max(0, left - balance);
  
  	tc9154a_set_attenuation(fmr2, abs(left - 68), TC9154A_CHANNEL_LEFT);
  	tc9154a_set_attenuation(fmr2, abs(right - 68), TC9154A_CHANNEL_RIGHT);
  
  	return 0;
  }
  
  static const struct v4l2_ctrl_ops fmr2_ctrl_ops = {
  	.s_ctrl = fmr2_s_ctrl,
  };
  
  static int fmr2_tea_ext_init(struct snd_tea575x *tea)
  {
  	struct fmr2 *fmr2 = tea->private_data;
  
  	/* FMR2 can have volume control, FMD2 can't (uses SB16 mixer) */
  	if (!fmr2->is_fmd2 && inb(fmr2->io) & FMR2_HASVOL) {
  		fmr2->volume = v4l2_ctrl_new_std(&tea->ctrl_handler, &fmr2_ctrl_ops, V4L2_CID_AUDIO_VOLUME, 0, 68, 2, 56);
  		fmr2->balance = v4l2_ctrl_new_std(&tea->ctrl_handler, &fmr2_ctrl_ops, V4L2_CID_AUDIO_BALANCE, -68, 68, 2, 0);
  		if (tea->ctrl_handler.error) {
  			printk(KERN_ERR "radio-sf16fmr2: can't initialize controls
  ");
  			return tea->ctrl_handler.error;
  		}
  	}
  
  	return 0;
  }
  
  static struct pnp_device_id fmr2_pnp_ids[] = {
  	{ .id = "MFRad13" }, /* tuner subdevice of SF16-FMD2 */
  	{ .id = "" }
  };
  MODULE_DEVICE_TABLE(pnp, fmr2_pnp_ids);
  
  static int fmr2_probe(struct fmr2 *fmr2, struct device *pdev, int io)
  {
  	int err, i;
  	char *card_name = fmr2->is_fmd2 ? "SF16-FMD2" : "SF16-FMR2";
  
  	/* avoid errors if a card was already registered at given port */
  	for (i = 0; i < num_fmr2_cards; i++)
  		if (io == fmr2_cards[i]->io)
  			return -EBUSY;
  
  	strlcpy(fmr2->v4l2_dev.name, "radio-sf16fmr2",
  			sizeof(fmr2->v4l2_dev.name)),
  	fmr2->io = io;
  
  	if (!request_region(fmr2->io, 2, fmr2->v4l2_dev.name)) {
  		printk(KERN_ERR "radio-sf16fmr2: I/O port 0x%x already in use
  ", fmr2->io);
  		return -EBUSY;
  	}
  
  	dev_set_drvdata(pdev, fmr2);
  	err = v4l2_device_register(pdev, &fmr2->v4l2_dev);
  	if (err < 0) {
  		v4l2_err(&fmr2->v4l2_dev, "Could not register v4l2_device
  ");
  		release_region(fmr2->io, 2);
  		return err;
  	}
  	fmr2->tea.v4l2_dev = &fmr2->v4l2_dev;
  	fmr2->tea.private_data = fmr2;
  	fmr2->tea.radio_nr = radio_nr[num_fmr2_cards];
  	fmr2->tea.ops = &fmr2_tea_ops;
  	fmr2->tea.ext_init = fmr2_tea_ext_init;
  	strlcpy(fmr2->tea.card, card_name, sizeof(fmr2->tea.card));
  	snprintf(fmr2->tea.bus_info, sizeof(fmr2->tea.bus_info), "%s:%s",
  			fmr2->is_fmd2 ? "PnP" : "ISA", dev_name(pdev));
  
  	if (snd_tea575x_init(&fmr2->tea, THIS_MODULE)) {
  		printk(KERN_ERR "radio-sf16fmr2: Unable to detect TEA575x tuner
  ");
  		release_region(fmr2->io, 2);
  		return -ENODEV;
  	}
  
  	printk(KERN_INFO "radio-sf16fmr2: %s radio card at 0x%x.
  ",
  			card_name, fmr2->io);
  	return 0;
  }
  
  static int fmr2_isa_match(struct device *pdev, unsigned int ndev)
  {
  	struct fmr2 *fmr2 = kzalloc(sizeof(*fmr2), GFP_KERNEL);
  	if (!fmr2)
  		return 0;
  
  	if (fmr2_probe(fmr2, pdev, FMR2_PORT)) {
  		kfree(fmr2);
  		return 0;
  	}
  	dev_set_drvdata(pdev, fmr2);
  	fmr2_cards[num_fmr2_cards++] = fmr2;
  
  	return 1;
  }
  
  static int fmr2_pnp_probe(struct pnp_dev *pdev, const struct pnp_device_id *id)
  {
  	int ret;
  	struct fmr2 *fmr2 = kzalloc(sizeof(*fmr2), GFP_KERNEL);
  	if (!fmr2)
  		return -ENOMEM;
  
  	fmr2->is_fmd2 = true;
  	ret = fmr2_probe(fmr2, &pdev->dev, pnp_port_start(pdev, 0));
  	if (ret) {
  		kfree(fmr2);
  		return ret;
  	}
  	pnp_set_drvdata(pdev, fmr2);
  	fmr2_cards[num_fmr2_cards++] = fmr2;
  
  	return 0;
  }
  
  static void fmr2_remove(struct fmr2 *fmr2)
  {
  	snd_tea575x_exit(&fmr2->tea);
  	release_region(fmr2->io, 2);
  	v4l2_device_unregister(&fmr2->v4l2_dev);
  	kfree(fmr2);
  }
  
  static int fmr2_isa_remove(struct device *pdev, unsigned int ndev)
  {
  	fmr2_remove(dev_get_drvdata(pdev));
  
  	return 0;
  }
  
  static void fmr2_pnp_remove(struct pnp_dev *pdev)
  {
  	fmr2_remove(pnp_get_drvdata(pdev));
  	pnp_set_drvdata(pdev, NULL);
  }
  
  struct isa_driver fmr2_isa_driver = {
  	.match		= fmr2_isa_match,
  	.remove		= fmr2_isa_remove,
  	.driver		= {
  		.name	= "radio-sf16fmr2",
  	},
  };
  
  struct pnp_driver fmr2_pnp_driver = {
  	.name		= "radio-sf16fmr2",
  	.id_table	= fmr2_pnp_ids,
  	.probe		= fmr2_pnp_probe,
  	.remove		= fmr2_pnp_remove,
  };
  
  static int __init fmr2_init(void)
  {
  	int ret;
  
  	ret = pnp_register_driver(&fmr2_pnp_driver);
  	if (!ret)
  		pnp_registered = true;
  	ret = isa_register_driver(&fmr2_isa_driver, 1);
  	if (!ret)
  		isa_registered = true;
  
  	return (pnp_registered || isa_registered) ? 0 : ret;
  }
  
  static void __exit fmr2_exit(void)
  {
  	if (pnp_registered)
  		pnp_unregister_driver(&fmr2_pnp_driver);
  	if (isa_registered)
  		isa_unregister_driver(&fmr2_isa_driver);
  }
  
  module_init(fmr2_init);
  module_exit(fmr2_exit);