//driver_i2cdmx.c:

/*
 *      Copyright (C) Philipp 'ph3-der-loewe' Schafft - 2011-2015
 *
 *  This file is part of roard a part of RoarAudio,
 *  a cross-platform sound system for both, home and professional use.
 *  See README for details.
 *
 *  This file is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 3
 *  as published by the Free Software Foundation.
 *
 *  RoarAudio 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 software; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, USA.
 *
 */

#include "roard.h"

#ifdef ROAR_HAVE_DRIVER_I2CDMX

#include <linux/i2c.h>
#include <linux/i2c-dev.h>

// hard disable SPI mode.
#ifdef ROAR_HAVE_H_LINUX_SPI_SPIDEV
#undef ROAR_HAVE_H_LINUX_SPI_SPIDEV
#endif

#ifdef ROAR_HAVE_H_LINUX_SPI_SPIDEV
#include <linux/spi/spidev.h>
#include <sys/ioctl.h>

#define TRANSFER_DELAY 50
#define TRANSFER_SPEED 100000
#define TRANSFER_BPW   8
#define TRANSFER_CHANS 24
#define TRANSFER_SIZE  (TRANSFER_CHANS+6)
#define SPI_DEVICE     "file://dev/spidev0.0"
#endif

#define DEFAULT_DEVICE  "/dev/i2c-1"

#define DEV_TYPE        0x01 /* RI2C_DEV_BRIDGE */
#define DEV_SUBTYPE     0x01 /* RI2C_SUBTYPE_BRIDGE_CONVERTER */
#define DEVSTATUS_READY 0x01 /* RI2C_STATUS0_DEVICE_READY */
#define CAPS0_DMX512    0x10 /* RI2C_CAPS0_BRIDGE_DMX512 */

#define MIN_ADDR        0x20
#define MAX_ADDR        0x70
#define MAX_BUSSES      8

#define ADDR_IFVERSION  0
#define ADDR_DEVSTATUS  1
#define ADDR_COMMAND    2
#define ADDR_DEVERROR   3
#define ADDR_BANK       4
#define ADDR_DATA       5
#define ADDR_VENDOR     (ADDR_BANK+2)
#define ADDR_TYPE       (ADDR_BANK+3)
#define ADDR_SUBTYPE    (ADDR_BANK+4)
#define ADDR_PVENDOR    (ADDR_BANK+10)
#define ADDR_PTYPE      (ADDR_BANK+11)
#define ADDR_PSUBTYPE   (ADDR_BANK+12)
#define ADDR_CAPS0      (ADDR_BANK+13)

#define COMMAND_DEVINFO 0x00
#define COMMAND_DMX     0x3f

struct driver_i2cdmx {
 struct roar_vio_calls vio;
 struct roar_vio_calls spi;
 int have_spi;
 uint8_t slave;
 size_t startaddr;
 size_t len;
#ifdef ROAR_HAVE_H_LINUX_SPI_SPIDEV
 char txtransfer[TRANSFER_SIZE];
 char rxtransfer[TRANSFER_SIZE];
#endif
};

#ifdef ROAR_HAVE_H_LINUX_SPI_SPIDEV
static int __spi_transfer(struct driver_i2cdmx * self, size_t offset_in, size_t offset_out, size_t len) {
 struct spi_ioc_transfer transfer_buffer = {
  .tx_buf = (unsigned long) self->txtransfer,
  .rx_buf = (unsigned long) self->rxtransfer,
  .len = len,
  .delay_usecs = TRANSFER_DELAY,
  .speed_hz = TRANSFER_SPEED,
  .bits_per_word = TRANSFER_BPW,
 };
 struct roar_vio_sysio_ioctl ctl = {.cmd = SPI_IOC_MESSAGE(1), .argp = &transfer_buffer};

 self->txtransfer[0] = 1; // command
 self->txtransfer[1] = len;
 self->txtransfer[2] = (offset_in & 0xFF00) >> 8;
 self->txtransfer[3] =  offset_in & 0x00FF;
 self->txtransfer[4] = (offset_in & 0xFF00) >> 8;
 self->txtransfer[5] =  offset_in & 0x00FF;

 if ( roar_vio_ctl(&(self->spi), ROAR_VIO_CTL_SYSIO_IOCTL, &ctl) == -1 )
  return -1;

 return 0;
}
#endif

static inline int __i2c_set_slave(struct driver_i2cdmx * self) {
 struct roar_vio_sysio_ioctl ctl = {.cmd = I2C_SLAVE, .argp = (void*)(int)self->slave};

 return roar_vio_ctl(&(self->vio), ROAR_VIO_CTL_SYSIO_IOCTL, &ctl);
}

static inline int16_t __i2c_read(struct driver_i2cdmx * self, size_t off) {
 union i2c_smbus_data data = {.byte = 0};
 struct i2c_smbus_ioctl_data args = {.read_write = I2C_SMBUS_READ, .command = off, .size = I2C_SMBUS_BYTE_DATA, .data = &data};
 struct roar_vio_sysio_ioctl ctl = {.cmd = I2C_SMBUS, .argp = &args};
 int ret = roar_vio_ctl(&(self->vio), ROAR_VIO_CTL_SYSIO_IOCTL, &ctl);

 if ( ret == -1 )
  return (int16_t)-1;

 return (int16_t)(uint16_t)(uint8_t)data.byte;
}

static inline int __i2c_write(struct driver_i2cdmx * self, size_t off, const uint8_t value) {
 union i2c_smbus_data data = {.byte = value};
 struct i2c_smbus_ioctl_data args = {.read_write = I2C_SMBUS_WRITE, .command = off, .size = I2C_SMBUS_BYTE_DATA, .data = &data};
 struct roar_vio_sysio_ioctl ctl = {.cmd = I2C_SMBUS, .argp = &args};

 return roar_vio_ctl(&(self->vio), ROAR_VIO_CTL_SYSIO_IOCTL, &ctl);
}

static inline int __i2c_write_block(struct driver_i2cdmx * self, size_t off, const uint8_t * value) {
 union i2c_smbus_data data;
 struct i2c_smbus_ioctl_data args = {.read_write = I2C_SMBUS_WRITE, .command = off, .size = I2C_SMBUS_I2C_BLOCK_BROKEN, .data = &data};
 struct roar_vio_sysio_ioctl ctl = {.cmd = I2C_SMBUS, .argp = &args};
 size_t i;

 for (i = 0; i < sizeof(data.block); i++)
  data.block[i] = 0xAF;

 data.block[0] = I2C_SMBUS_BLOCK_MAX;

 for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++)
  data.block[i+1] = value[i];

 return roar_vio_ctl(&(self->vio), ROAR_VIO_CTL_SYSIO_IOCTL, &ctl);
}

static inline int __i2c_command(struct driver_i2cdmx * self, uint8_t command) {
 int16_t ret;

 if ( __i2c_write(self, ADDR_COMMAND, command) == -1 )
  return -1;

 ret = __i2c_read(self, ADDR_DEVERROR);
 if ( ret == (int16_t)-1 )
  return -1;

 if ( ret == ROAR_ERROR_NONE )
  return 0;

 roar_err_set(ret);
 return -1;
}

static inline int __i2c_start_dmx(struct driver_i2cdmx * self) {
 return __i2c_command(self, COMMAND_DMX);
}

static int __open_test_device_type(int16_t vendor, int16_t type, int16_t subtype) {
 if ( vendor == -1 || type == -1 || subtype == -1 )
  return -1;

 if ( vendor != ROAR_VID_ROARAUDIO || type != DEV_TYPE || subtype != DEV_SUBTYPE ) {
  roar_err_set(ROAR_ERROR_TYPEMM);
  return -1;
 }

 return 0;
}

static int __open_test_device(struct driver_i2cdmx * self) {
 int16_t ret;
 int16_t vendor, type, subtype;

#define __check_response(resp,test,error) if ( (resp) == (int16_t)-1 ) return -1; if ( !(test) ) { roar_err_set((error)); return -1; }

 // test for device interface version
 ret = __i2c_read(self, ADDR_IFVERSION);
 __check_response(ret, ret == 0, ROAR_ERROR_NSVERSION);

 // test for device overall status
 ret = __i2c_read(self, ADDR_DEVSTATUS);
 __check_response(ret, ret & DEVSTATUS_READY, ROAR_ERROR_BADSTATE);

 // Request device infos
 if ( __i2c_command(self, COMMAND_DEVINFO) == -1 )
  return -1;

 // Check device infos
 // first check device type, then parent device type:
 vendor  = __i2c_read(self, ADDR_VENDOR);
 type    = __i2c_read(self, ADDR_TYPE);
 subtype = __i2c_read(self, ADDR_SUBTYPE);

 if ( __open_test_device_type(vendor, type, subtype) == -1 ) {
  vendor  = __i2c_read(self, ADDR_PVENDOR);
  type    = __i2c_read(self, ADDR_PTYPE);
  subtype = __i2c_read(self, ADDR_PSUBTYPE);

  if (  __open_test_device_type(vendor, type, subtype) == -1 )
   return -1;
 }

 // check for DMX512 support:

 ret = __i2c_read(self, ADDR_CAPS0);
 __check_response(ret, ret & CAPS0_DMX512, ROAR_ERROR_TYPEMM);

 return 0;
}

static int __open_scan_devices(struct driver_i2cdmx * self) {
 uint8_t i;

 for (i = MIN_ADDR; i < MAX_ADDR; i++) {
  self->slave = i;

  if ( __i2c_set_slave(self) == -1 )
   continue;

  if ( __open_test_device(self) == -1 )
   continue;

  return 0;
 }

 self->slave = 0;
 roar_err_set(ROAR_ERROR_NOENT);
 return -1;
}

static int __open_device_and_slave(struct driver_i2cdmx * self, int autoconf, const char * device) {
 char filename[40];
 char * p;
 int need_autoconf = 0;
 int ret;
 int err;

 // test if the device exist.
 if ( roar_vio_open_dstr_simple(&(self->vio), device, ROAR_VIOF_READWRITE) == 0 ) {
  need_autoconf = 1;
 } else {
  // the device doesn't exist. We guss it is in form $device/$slaveid.
  strncpy(filename, device, sizeof(filename));
  p = strrchr(filename, '/');
  if ( p == NULL ) {
   // it doesn't seem to be in the given form so it seems it was just a device name of an missingd evice.
   roar_err_set(ROAR_ERROR_NOENT);
   return -1;
  }

  *p = 0;
  p++;

  // now we have the device name in filename, and the slave ID in p.
  self->slave = atoi(p);

  // little test to protect the user from doing dumb things.
  if ( self->slave == 0 ) {
   roar_err_set(ROAR_ERROR_INVAL);
   return -1;
  }

  if ( roar_vio_open_dstr_simple(&(self->vio), filename, ROAR_VIOF_READWRITE) == -1 )
   return -1;
 }

 // ok, the bus is now open. Let's open the device:

 if ( need_autoconf ) {
  ret = __open_scan_devices(self);
 } else {
  ret = __i2c_set_slave(self);
  if ( ret == 0 )
   ret = __open_test_device(self);
 }

 if ( ret == -1 ) {
  err = roar_error;
  roar_vio_close(&(self->vio));
  roar_err_set(err);
 }

 return ret;
}

static int __open_scan_busses(struct driver_i2cdmx * self) {
 char filename[20];
 int i;
 int ret;

 for (i = 0; i < MAX_BUSSES; i++) {
  snprintf(filename, sizeof(filename), "/dev/i2c-%i", i);
  ret = __open_device_and_slave(self, 1, filename);
  if ( ret == 0 )
   return 0;
 }

 roar_err_set(ROAR_ERROR_NOENT);
 return -1;
}

static int __i2c_write_channel(struct driver_i2cdmx * self, size_t channel, uint8_t value) {
 size_t bank, offset;

 bank = channel/32;
 offset = bank*32;

 if ( __i2c_write(self, ADDR_BANK, bank) == -1 )
  return -1;

 return __i2c_write(self, ADDR_DATA+channel-offset, value);
}

static int __i2c_write_channel_block(struct driver_i2cdmx * self, size_t channel, const uint8_t * value) {
 size_t bank, offset;

 bank = channel/32;
 offset = bank*32;

 if ( __i2c_write(self, ADDR_BANK, bank) == -1 )
  return -1;

 return __i2c_write_block(self, ADDR_DATA+channel-offset, value);
}

static ssize_t        __vio_read    (struct roar_vio_calls * vio, void *buf, size_t count) {
 struct driver_i2cdmx * self;

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 self = vio->inst;

 if ( count != 512 ) {
  roar_err_set(ROAR_ERROR_INVAL);
  return -1;
 }

 if ( __i2c_start_dmx(self) == -1 )
  return -1;

 memset(buf, 0, count); // optimize this...
#ifdef ROAR_HAVE_H_LINUX_SPI_SPIDEV
 memcpy(buf, self->rxtransfer+6, sizeof(self->rxtransfer)-6);
#endif
 return 0;
}

static ssize_t        __vio_write   (struct roar_vio_calls * vio, void *buf, size_t count) {
 struct driver_i2cdmx * self;
 size_t i;
// size_t endaddr;
 size_t todo;

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 self = vio->inst;

 if ( count != 512 ) {
  roar_err_set(ROAR_ERROR_INVAL);
  return -1;
 }

 if ( __i2c_start_dmx(self) == -1 )
  return -1;

/*
 for (i = self->startaddr, endaddr = self->startaddr + self->len; i < endaddr; i++)
  if ( __i2c_write_channel(self, i, ((uint8_t*)buf)[i]) == -1 )
   return -1;
 */

 i = self->startaddr;
 todo = self->len;
 while (todo) {
  if ( todo >= I2C_SMBUS_BLOCK_MAX ) {
   if ( __i2c_write_channel_block(self, i, &(((const uint8_t*)buf)[i])) == -1 )
    return -1;
   i += I2C_SMBUS_BLOCK_MAX;
   todo -= I2C_SMBUS_BLOCK_MAX;
  } else {
   if ( __i2c_write_channel(self, i, ((uint8_t*)buf)[i]) == -1 )
    return -1;
   i++;
   todo--;
  }
 }
#ifdef ROAR_HAVE_H_LINUX_SPI_SPIDEV
 memcpy(self->txtransfer+6, buf, sizeof(self->txtransfer)-6);
 __spi_transfer(self, 0, 0, TRANSFER_CHANS);
#endif

 return count;
}

static int            __vio_ctl     (struct roar_vio_calls * vio, roar_vio_ctl_t cmd, void * data) {
 struct driver_i2cdmx * self;

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 self = vio->inst;

 switch (cmd) {
  case ROAR_VIO_CTL_SET_SSTREAM:
    if ( ROAR_STREAM(data)->dir != ROAR_DIR_LIGHT_OUT && ROAR_STREAM(data)->dir != ROAR_DIR_LIGHT_IN ) {
     ROAR_STREAM(data)->dir = ROAR_DIR_LIGHT_OUT;
    }
    ROAR_STREAM_SERVER(data)->codec_orgi = ROAR_CODEC_DMX512;
   break;
  default:
   roar_err_set(ROAR_ERROR_BADRQC);
   return -1;
 }

 return 0;
}

static int            __vio_close   (struct roar_vio_calls * vio) {
 struct driver_i2cdmx * self = vio->inst;
 roar_vio_close(&(self->vio));
 if ( self->have_spi )
  roar_vio_close(&(self->spi));
 roar_mm_free(self);
 return 0;
}

int driver_i2cdmx_open_vio  (struct roar_vio_calls * inst, char * device, struct roar_audio_info * info, int fh, struct roar_stream_server * sstream) {
 struct driver_i2cdmx * self;
 int autoconf = 1;
 int ret;

 if ( fh != -1 ) {
  roar_err_set(ROAR_ERROR_NOSYS);
  return -1;
 }

 self = roar_mm_malloc(sizeof(struct driver_i2cdmx));
 if ( self == NULL ) {
  return -1;
 }
 memset(self, 0, sizeof(*self));
 self->have_spi  = 0;
 self->startaddr = 0;
 self->len       = info->channels;

 info->bits      = 8;
 info->codec     = ROAR_CODEC_DMX512;

 if ( device == NULL && !autoconf ) {
  device = DEFAULT_DEVICE;
 }

 if ( device == NULL ) {
  ret = __open_scan_busses(self);
 } else {
  ret = __open_device_and_slave(self, autoconf, device);
 }

 if ( ret == -1 ) {
  roar_mm_free_noerror(self);
  return -1;
 }

#if defined(ROAR_HAVE_H_LINUX_SPI_SPIDEV) && defined(SPI_DEVICE)
 if ( roar_vio_open_dstr_simple(&(self->spi), SPI_DEVICE, ROAR_VIOF_READWRITE) == 0 )
  self->have_spi = 1;
#endif

 roar_vio_clear_calls(inst);
 inst->inst  = self;
 inst->read  = __vio_read;
 inst->write = __vio_write;
 inst->close = __vio_close;
 inst->ctl   = __vio_ctl;

 return 0;
}
#endif