firmware/target/arm/as3525/fmradio-i2c-as3525.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2008 by Bertrik Sikken
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 /*
  23     This is the fmradio_i2c interface, used by the radio driver
  24     to communicate with the radio tuner chip.
  25
  26     It is implemented using the generic i2c driver, which does "bit-banged"
  27     I2C with a couple of GPIO pins.
  28  */
  29
  30 #include "as3525.h"
  31 #include "generic_i2c.h"
  32 #include "fmradio_i2c.h"
  33
  34 #if     defined(SANSA_CLIP) || defined(SANSA_C200V2)
  35 #define I2C_GPIO(x) GPIOB_PIN(x)
  36 #define I2C_GPIO_DIR GPIOB_DIR
  37 #define I2C_SCL_PIN 4
  38 #define I2C_SDA_PIN 5
  39
  40 #elif   defined(SANSA_M200V4)
  41 #define I2C_GPIO(x) GPIOD_PIN(x)
  42 #define I2C_GPIO_DIR GPIOD_DIR
  43 #define I2C_SCL_PIN 7
  44 #define I2C_SDA_PIN 6
  45
  46 #elif   defined(SANSA_FUZE) || defined(SANSA_E200V2)
  47 #define I2C_GPIO(x) GPIOA_PIN(x)
  48 #define I2C_GPIO_DIR GPIOA_DIR
  49 #define I2C_SCL_PIN 6
  50 #define I2C_SDA_PIN 7
  51
  52 #elif
  53 #error no FM I2C GPIOPIN defines
  54 #endif
  55
  56 static int fm_i2c_bus;
  57
  58 static void fm_scl_hi(void)
  59 {
  60     I2C_GPIO(I2C_SCL_PIN) = 1 << I2C_SCL_PIN;
  61 }
  62
  63 static void fm_scl_lo(void)
  64 {
  65     I2C_GPIO(I2C_SCL_PIN) = 0;
  66 }
  67
  68 static void fm_sda_hi(void)
  69 {
  70     I2C_GPIO(I2C_SDA_PIN) = 1 << I2C_SDA_PIN;
  71 }
  72
  73 static void fm_sda_lo(void)
  74 {
  75     I2C_GPIO(I2C_SDA_PIN) = 0;
  76 }
  77
  78 static void fm_sda_input(void)
  79 {
  80     I2C_GPIO_DIR &= ~(1 << I2C_SDA_PIN);
  81 }
  82
  83 static void fm_sda_output(void)
  84 {
  85     I2C_GPIO_DIR |= 1 << I2C_SDA_PIN;
  86 }
  87
  88 static void fm_scl_input(void)
  89 {
  90     I2C_GPIO_DIR &= ~(1 << I2C_SCL_PIN);
  91 }
  92
  93 static void fm_scl_output(void)
  94 {
  95     I2C_GPIO_DIR |= 1 << I2C_SCL_PIN;
  96 }
  97
  98 static int fm_sda(void)
  99 {
 100     return I2C_GPIO(I2C_SDA_PIN);
 101 }
 102
 103 static int fm_scl(void)
 104 {
 105     return I2C_GPIO(I2C_SCL_PIN);
 106 }
 107
 108 /* simple and crude delay, used for all delays in the generic i2c driver */
 109 static void fm_delay(void)
 110 {
 111     volatile int i;
 112
 113     /* this loop is uncalibrated and could use more sophistication */
 114     for (i = 0; i < 20; i++) {
 115     }
 116 }
 117
 118 /* interface towards the generic i2c driver */
 119 static const struct i2c_interface fm_i2c_interface = {
 120     .scl_hi = fm_scl_hi,
 121     .scl_lo = fm_scl_lo,
 122     .sda_hi = fm_sda_hi,
 123     .sda_lo = fm_sda_lo,
 124     .sda_input = fm_sda_input,
 125     .sda_output = fm_sda_output,
 126     .scl_input = fm_scl_input,
 127     .scl_output = fm_scl_output,
 128     .scl = fm_scl,
 129     .sda = fm_sda,
 130
 131     .delay_hd_sta = fm_delay,
 132     .delay_hd_dat = fm_delay,
 133     .delay_su_dat = fm_delay,
 134     .delay_su_sto = fm_delay,
 135     .delay_su_sta = fm_delay,
 136     .delay_thigh = fm_delay
 137 };
 138
 139 /* initialise i2c for fmradio */
 140 void fmradio_i2c_init(void)
 141 {
 142     fm_i2c_bus = i2c_add_node(&fm_i2c_interface);
 143 }
 144
 145 int fmradio_i2c_write(unsigned char address, const unsigned char* buf, int count)
 146 {
 147     return i2c_write_data(fm_i2c_bus, address, -1, buf, count);
 148 }
 149
 150 int fmradio_i2c_read(unsigned char address, unsigned char* buf, int count)
 151 {
 152     return i2c_read_data(fm_i2c_bus, address, -1, buf, count);
 153 }
 154
 155
 156