/*
   * driver/media/radio/radio-tea5764.c
   *
   * Driver for TEA5764 radio chip for linux 2.6.
   * This driver is for TEA5764 chip from NXP, used in EZX phones from Motorola.
   * The I2C protocol is used for communicate with chip.
   *
   * Based in radio-tea5761.c Copyright (C) 2005 Nokia Corporation
   *
   *  Copyright (c) 2008 Fabio Belavenuto <belavenuto@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
   *
   * History:
   * 2008-12-06   Fabio Belavenuto <belavenuto@gmail.com>
   *              initial code
   *
   * TODO:
   *  add platform_data support for IRQs platform dependencies
   *  add RDS support
   */
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/module.h>
  #include <linux/init.h>			/* Initdata			*/
  #include <linux/videodev2.h>		/* kernel radio structs		*/
  #include <linux/i2c.h>			/* I2C				*/
  #include <media/v4l2-common.h>
  #include <media/v4l2-ioctl.h>
  #include <media/v4l2-device.h>
  #include <media/v4l2-ctrls.h>
  #include <media/v4l2-event.h>
  
  #define DRIVER_VERSION	"0.0.2"
  
  #define DRIVER_AUTHOR	"Fabio Belavenuto <belavenuto@gmail.com>"
  #define DRIVER_DESC	"A driver for the TEA5764 radio chip for EZX Phones."
  
  #define PINFO(format, ...)\
  	printk(KERN_INFO KBUILD_MODNAME ": "\
  		DRIVER_VERSION ": " format "
  ", ## __VA_ARGS__)
  #define PWARN(format, ...)\
  	printk(KERN_WARNING KBUILD_MODNAME ": "\
  		DRIVER_VERSION ": " format "
  ", ## __VA_ARGS__)
  # define PDEBUG(format, ...)\
  	printk(KERN_DEBUG KBUILD_MODNAME ": "\
  		DRIVER_VERSION ": " format "
  ", ## __VA_ARGS__)
  
  /* Frequency limits in MHz -- these are European values.  For Japanese
  devices, that would be 76000 and 91000.  */
  #define FREQ_MIN  87500U
  #define FREQ_MAX 108000U
  #define FREQ_MUL 16
  
  /* TEA5764 registers */
  #define TEA5764_MANID		0x002b
  #define TEA5764_CHIPID		0x5764
  
  #define TEA5764_INTREG_BLMSK	0x0001
  #define TEA5764_INTREG_FRRMSK	0x0002
  #define TEA5764_INTREG_LEVMSK	0x0008
  #define TEA5764_INTREG_IFMSK	0x0010
  #define TEA5764_INTREG_BLMFLAG	0x0100
  #define TEA5764_INTREG_FRRFLAG	0x0200
  #define TEA5764_INTREG_LEVFLAG	0x0800
  #define TEA5764_INTREG_IFFLAG	0x1000
  
  #define TEA5764_FRQSET_SUD	0x8000
  #define TEA5764_FRQSET_SM	0x4000
  
  #define TEA5764_TNCTRL_PUPD1	0x8000
  #define TEA5764_TNCTRL_PUPD0	0x4000
  #define TEA5764_TNCTRL_BLIM	0x2000
  #define TEA5764_TNCTRL_SWPM	0x1000
  #define TEA5764_TNCTRL_IFCTC	0x0800
  #define TEA5764_TNCTRL_AFM	0x0400
  #define TEA5764_TNCTRL_SMUTE	0x0200
  #define TEA5764_TNCTRL_SNC	0x0100
  #define TEA5764_TNCTRL_MU	0x0080
  #define TEA5764_TNCTRL_SSL1	0x0040
  #define TEA5764_TNCTRL_SSL0	0x0020
  #define TEA5764_TNCTRL_HLSI	0x0010
  #define TEA5764_TNCTRL_MST	0x0008
  #define TEA5764_TNCTRL_SWP	0x0004
  #define TEA5764_TNCTRL_DTC	0x0002
  #define TEA5764_TNCTRL_AHLSI	0x0001
  
  #define TEA5764_TUNCHK_LEVEL(x)	(((x) & 0x00F0) >> 4)
  #define TEA5764_TUNCHK_IFCNT(x) (((x) & 0xFE00) >> 9)
  #define TEA5764_TUNCHK_TUNTO	0x0100
  #define TEA5764_TUNCHK_LD	0x0008
  #define TEA5764_TUNCHK_STEREO	0x0004
  
  #define TEA5764_TESTREG_TRIGFR	0x0800
  
  struct tea5764_regs {
  	u16 intreg;				/* INTFLAG & INTMSK */
  	u16 frqset;				/* FRQSETMSB & FRQSETLSB */
  	u16 tnctrl;				/* TNCTRL1 & TNCTRL2 */
  	u16 frqchk;				/* FRQCHKMSB & FRQCHKLSB */
  	u16 tunchk;				/* IFCHK & LEVCHK */
  	u16 testreg;				/* TESTBITS & TESTMODE */
  	u16 rdsstat;				/* RDSSTAT1 & RDSSTAT2 */
  	u16 rdslb;				/* RDSLBMSB & RDSLBLSB */
  	u16 rdspb;				/* RDSPBMSB & RDSPBLSB */
  	u16 rdsbc;				/* RDSBBC & RDSGBC */
  	u16 rdsctrl;				/* RDSCTRL1 & RDSCTRL2 */
  	u16 rdsbbl;				/* PAUSEDET & RDSBBL */
  	u16 manid;				/* MANID1 & MANID2 */
  	u16 chipid;				/* CHIPID1 & CHIPID2 */
  } __attribute__ ((packed));
  
  struct tea5764_write_regs {
  	u8 intreg;				/* INTMSK */
  	__be16 frqset;				/* FRQSETMSB & FRQSETLSB */
  	__be16 tnctrl;				/* TNCTRL1 & TNCTRL2 */
  	__be16 testreg;				/* TESTBITS & TESTMODE */
  	__be16 rdsctrl;				/* RDSCTRL1 & RDSCTRL2 */
  	__be16 rdsbbl;				/* PAUSEDET & RDSBBL */
  } __attribute__ ((packed));
  
  #ifdef CONFIG_RADIO_TEA5764_XTAL
  #define RADIO_TEA5764_XTAL 1
  #else
  #define RADIO_TEA5764_XTAL 0
  #endif
  
  static int radio_nr = -1;
  static int use_xtal = RADIO_TEA5764_XTAL;
  
  struct tea5764_device {
  	struct v4l2_device		v4l2_dev;
  	struct v4l2_ctrl_handler	ctrl_handler;
  	struct i2c_client		*i2c_client;
  	struct video_device		vdev;
  	struct tea5764_regs		regs;
  	struct mutex			mutex;
  };
  
  /* I2C code related */
  static int tea5764_i2c_read(struct tea5764_device *radio)
  {
  	int i;
  	u16 *p = (u16 *) &radio->regs;
  
  	struct i2c_msg msgs[1] = {
  		{	.addr = radio->i2c_client->addr,
  			.flags = I2C_M_RD,
  			.len = sizeof(radio->regs),
  			.buf = (void *)&radio->regs
  		},
  	};
  	if (i2c_transfer(radio->i2c_client->adapter, msgs, 1) != 1)
  		return -EIO;
  	for (i = 0; i < sizeof(struct tea5764_regs) / sizeof(u16); i++)
  		p[i] = __be16_to_cpu((__force __be16)p[i]);
  
  	return 0;
  }
  
  static int tea5764_i2c_write(struct tea5764_device *radio)
  {
  	struct tea5764_write_regs wr;
  	struct tea5764_regs *r = &radio->regs;
  	struct i2c_msg msgs[1] = {
  		{
  			.addr = radio->i2c_client->addr,
  			.len = sizeof(wr),
  			.buf = (void *)&wr
  		},
  	};
  	wr.intreg  = r->intreg & 0xff;
  	wr.frqset  = __cpu_to_be16(r->frqset);
  	wr.tnctrl  = __cpu_to_be16(r->tnctrl);
  	wr.testreg = __cpu_to_be16(r->testreg);
  	wr.rdsctrl = __cpu_to_be16(r->rdsctrl);
  	wr.rdsbbl  = __cpu_to_be16(r->rdsbbl);
  	if (i2c_transfer(radio->i2c_client->adapter, msgs, 1) != 1)
  		return -EIO;
  	return 0;
  }
  
  static void tea5764_power_up(struct tea5764_device *radio)
  {
  	struct tea5764_regs *r = &radio->regs;
  
  	if (!(r->tnctrl & TEA5764_TNCTRL_PUPD0)) {
  		r->tnctrl &= ~(TEA5764_TNCTRL_AFM | TEA5764_TNCTRL_MU |
  			       TEA5764_TNCTRL_HLSI);
  		if (!use_xtal)
  			r->testreg |= TEA5764_TESTREG_TRIGFR;
  		else
  			r->testreg &= ~TEA5764_TESTREG_TRIGFR;
  
  		r->tnctrl |= TEA5764_TNCTRL_PUPD0;
  		tea5764_i2c_write(radio);
  	}
  }
  
  static void tea5764_power_down(struct tea5764_device *radio)
  {
  	struct tea5764_regs *r = &radio->regs;
  
  	if (r->tnctrl & TEA5764_TNCTRL_PUPD0) {
  		r->tnctrl &= ~TEA5764_TNCTRL_PUPD0;
  		tea5764_i2c_write(radio);
  	}
  }
  
  static void tea5764_set_freq(struct tea5764_device *radio, int freq)
  {
  	struct tea5764_regs *r = &radio->regs;
  
  	/* formula: (freq [+ or -] 225000) / 8192 */
  	if (r->tnctrl & TEA5764_TNCTRL_HLSI)
  		r->frqset = (freq + 225000) / 8192;
  	else
  		r->frqset = (freq - 225000) / 8192;
  }
  
  static int tea5764_get_freq(struct tea5764_device *radio)
  {
  	struct tea5764_regs *r = &radio->regs;
  
  	if (r->tnctrl & TEA5764_TNCTRL_HLSI)
  		return (r->frqchk * 8192) - 225000;
  	else
  		return (r->frqchk * 8192) + 225000;
  }
  
  /* tune an frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
  static void tea5764_tune(struct tea5764_device *radio, int freq)
  {
  	tea5764_set_freq(radio, freq);
  	if (tea5764_i2c_write(radio))
  		PWARN("Could not set frequency!");
  }
  
  static void tea5764_set_audout_mode(struct tea5764_device *radio, int audmode)
  {
  	struct tea5764_regs *r = &radio->regs;
  	int tnctrl = r->tnctrl;
  
  	if (audmode == V4L2_TUNER_MODE_MONO)
  		r->tnctrl |= TEA5764_TNCTRL_MST;
  	else
  		r->tnctrl &= ~TEA5764_TNCTRL_MST;
  	if (tnctrl != r->tnctrl)
  		tea5764_i2c_write(radio);
  }
  
  static int tea5764_get_audout_mode(struct tea5764_device *radio)
  {
  	struct tea5764_regs *r = &radio->regs;
  
  	if (r->tnctrl & TEA5764_TNCTRL_MST)
  		return V4L2_TUNER_MODE_MONO;
  	else
  		return V4L2_TUNER_MODE_STEREO;
  }
  
  static void tea5764_mute(struct tea5764_device *radio, int on)
  {
  	struct tea5764_regs *r = &radio->regs;
  	int tnctrl = r->tnctrl;
  
  	if (on)
  		r->tnctrl |= TEA5764_TNCTRL_MU;
  	else
  		r->tnctrl &= ~TEA5764_TNCTRL_MU;
  	if (tnctrl != r->tnctrl)
  		tea5764_i2c_write(radio);
  }
  
  /* V4L2 vidioc */
  static int vidioc_querycap(struct file *file, void  *priv,
  					struct v4l2_capability *v)
  {
  	struct tea5764_device *radio = video_drvdata(file);
  	struct video_device *dev = &radio->vdev;
  
  	strlcpy(v->driver, dev->dev.driver->name, sizeof(v->driver));
  	strlcpy(v->card, dev->name, sizeof(v->card));
  	snprintf(v->bus_info, sizeof(v->bus_info),
  		 "I2C:%s", dev_name(&dev->dev));
  	v->device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
  	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
  	return 0;
  }
  
  static int vidioc_g_tuner(struct file *file, void *priv,
  				struct v4l2_tuner *v)
  {
  	struct tea5764_device *radio = video_drvdata(file);
  	struct tea5764_regs *r = &radio->regs;
  
  	if (v->index > 0)
  		return -EINVAL;
  
  	strlcpy(v->name, "FM", sizeof(v->name));
  	v->type = V4L2_TUNER_RADIO;
  	tea5764_i2c_read(radio);
  	v->rangelow   = FREQ_MIN * FREQ_MUL;
  	v->rangehigh  = FREQ_MAX * FREQ_MUL;
  	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
  	if (r->tunchk & TEA5764_TUNCHK_STEREO)
  		v->rxsubchans = V4L2_TUNER_SUB_STEREO;
  	else
  		v->rxsubchans = V4L2_TUNER_SUB_MONO;
  	v->audmode = tea5764_get_audout_mode(radio);
  	v->signal = TEA5764_TUNCHK_LEVEL(r->tunchk) * 0xffff / 0xf;
  	v->afc = TEA5764_TUNCHK_IFCNT(r->tunchk);
  
  	return 0;
  }
  
  static int vidioc_s_tuner(struct file *file, void *priv,
  				const struct v4l2_tuner *v)
  {
  	struct tea5764_device *radio = video_drvdata(file);
  
  	if (v->index > 0)
  		return -EINVAL;
  
  	tea5764_set_audout_mode(radio, v->audmode);
  	return 0;
  }
  
  static int vidioc_s_frequency(struct file *file, void *priv,
  				const struct v4l2_frequency *f)
  {
  	struct tea5764_device *radio = video_drvdata(file);
  	unsigned freq = f->frequency;
  
  	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
  		return -EINVAL;
  	if (freq == 0) {
  		/* We special case this as a power down control. */
  		tea5764_power_down(radio);
  		/* Yes, that's what is returned in this case. This
  		   whole special case is non-compliant and should really
  		   be replaced with something better, but changing this
  		   might well break code that depends on this behavior.
  		   So we keep it as-is. */
  		return -EINVAL;
  	}
  	freq = clamp(freq, FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
  	tea5764_power_up(radio);
  	tea5764_tune(radio, (freq * 125) / 2);
  	return 0;
  }
  
  static int vidioc_g_frequency(struct file *file, void *priv,
  				struct v4l2_frequency *f)
  {
  	struct tea5764_device *radio = video_drvdata(file);
  	struct tea5764_regs *r = &radio->regs;
  
  	if (f->tuner != 0)
  		return -EINVAL;
  	tea5764_i2c_read(radio);
  	f->type = V4L2_TUNER_RADIO;
  	if (r->tnctrl & TEA5764_TNCTRL_PUPD0)
  		f->frequency = (tea5764_get_freq(radio) * 2) / 125;
  	else
  		f->frequency = 0;
  
  	return 0;
  }
  
  static int tea5764_s_ctrl(struct v4l2_ctrl *ctrl)
  {
  	struct tea5764_device *radio =
  		container_of(ctrl->handler, struct tea5764_device, ctrl_handler);
  
  	switch (ctrl->id) {
  	case V4L2_CID_AUDIO_MUTE:
  		tea5764_mute(radio, ctrl->val);
  		return 0;
  	}
  	return -EINVAL;
  }
  
  static const struct v4l2_ctrl_ops tea5764_ctrl_ops = {
  	.s_ctrl = tea5764_s_ctrl,
  };
  
  /* File system interface */
  static const struct v4l2_file_operations tea5764_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 tea5764_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,
  };
  
  /* V4L2 interface */
  static struct video_device tea5764_radio_template = {
  	.name		= "TEA5764 FM-Radio",
  	.fops           = &tea5764_fops,
  	.ioctl_ops 	= &tea5764_ioctl_ops,
  	.release	= video_device_release_empty,
  };
  
  /* I2C probe: check if the device exists and register with v4l if it is */
  static int tea5764_i2c_probe(struct i2c_client *client,
  			     const struct i2c_device_id *id)
  {
  	struct tea5764_device *radio;
  	struct v4l2_device *v4l2_dev;
  	struct v4l2_ctrl_handler *hdl;
  	struct tea5764_regs *r;
  	int ret;
  
  	PDEBUG("probe");
  	radio = kzalloc(sizeof(struct tea5764_device), GFP_KERNEL);
  	if (!radio)
  		return -ENOMEM;
  
  	v4l2_dev = &radio->v4l2_dev;
  	ret = v4l2_device_register(&client->dev, v4l2_dev);
  	if (ret < 0) {
  		v4l2_err(v4l2_dev, "could not register v4l2_device
  ");
  		goto errfr;
  	}
  
  	hdl = &radio->ctrl_handler;
  	v4l2_ctrl_handler_init(hdl, 1);
  	v4l2_ctrl_new_std(hdl, &tea5764_ctrl_ops,
  			V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
  	v4l2_dev->ctrl_handler = hdl;
  	if (hdl->error) {
  		ret = hdl->error;
  		v4l2_err(v4l2_dev, "Could not register controls
  ");
  		goto errunreg;
  	}
  
  	mutex_init(&radio->mutex);
  	radio->i2c_client = client;
  	ret = tea5764_i2c_read(radio);
  	if (ret)
  		goto errunreg;
  	r = &radio->regs;
  	PDEBUG("chipid = %04X, manid = %04X", r->chipid, r->manid);
  	if (r->chipid != TEA5764_CHIPID ||
  		(r->manid & 0x0fff) != TEA5764_MANID) {
  		PWARN("This chip is not a TEA5764!");
  		ret = -EINVAL;
  		goto errunreg;
  	}
  
  	radio->vdev = tea5764_radio_template;
  
  	i2c_set_clientdata(client, radio);
  	video_set_drvdata(&radio->vdev, radio);
  	radio->vdev.lock = &radio->mutex;
  	radio->vdev.v4l2_dev = v4l2_dev;
  
  	/* initialize and power off the chip */
  	tea5764_i2c_read(radio);
  	tea5764_set_audout_mode(radio, V4L2_TUNER_MODE_STEREO);
  	tea5764_mute(radio, 1);
  	tea5764_power_down(radio);
  
  	ret = video_register_device(&radio->vdev, VFL_TYPE_RADIO, radio_nr);
  	if (ret < 0) {
  		PWARN("Could not register video device!");
  		goto errunreg;
  	}
  
  	PINFO("registered.");
  	return 0;
  errunreg:
  	v4l2_ctrl_handler_free(hdl);
  	v4l2_device_unregister(v4l2_dev);
  errfr:
  	kfree(radio);
  	return ret;
  }
  
  static int tea5764_i2c_remove(struct i2c_client *client)
  {
  	struct tea5764_device *radio = i2c_get_clientdata(client);
  
  	PDEBUG("remove");
  	if (radio) {
  		tea5764_power_down(radio);
  		video_unregister_device(&radio->vdev);
  		v4l2_ctrl_handler_free(&radio->ctrl_handler);
  		v4l2_device_unregister(&radio->v4l2_dev);
  		kfree(radio);
  	}
  	return 0;
  }
  
  /* I2C subsystem interface */
  static const struct i2c_device_id tea5764_id[] = {
  	{ "radio-tea5764", 0 },
  	{ }					/* Terminating entry */
  };
  MODULE_DEVICE_TABLE(i2c, tea5764_id);
  
  static struct i2c_driver tea5764_i2c_driver = {
  	.driver = {
  		.name = "radio-tea5764",
  	},
  	.probe = tea5764_i2c_probe,
  	.remove = tea5764_i2c_remove,
  	.id_table = tea5764_id,
  };
  
  module_i2c_driver(tea5764_i2c_driver);
  
  MODULE_AUTHOR(DRIVER_AUTHOR);
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_LICENSE("GPL");
  MODULE_VERSION(DRIVER_VERSION);
  
  module_param(use_xtal, int, 0);
  MODULE_PARM_DESC(use_xtal, "Chip have a xtal connected in board");
  module_param(radio_nr, int, 0);
  MODULE_PARM_DESC(radio_nr, "video4linux device number to use");