drivers/media/pci/cx88/cx88-vp3054-i2c.c

   1 /*
   2  * cx88-vp3054-i2c.c -- support for the secondary I2C bus of the
   3  *                      DNTV Live! DVB-T Pro (VP-3054), wired as:
   4  *                      GPIO[0] -> SCL, GPIO[1] -> SDA
   5  *
   6  * (c) 2005 Chris Pascoe <c.pascoe@itee.uq.edu.au>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  */
  18
  19 #include "cx88.h"
  20 #include "cx88-vp3054-i2c.h"
  21
  22 #include <linux/module.h>
  23 #include <linux/slab.h>
  24 #include <linux/init.h>
  25 #include <linux/io.h>
  26
  27 MODULE_DESCRIPTION("driver for cx2388x VP3054 design");
  28 MODULE_AUTHOR("Chris Pascoe <c.pascoe@itee.uq.edu.au>");
  29 MODULE_LICENSE("GPL");
  30
  31 /* ----------------------------------------------------------------------- */
  32
  33 static void vp3054_bit_setscl(void *data, int state)
  34 {
  35         struct cx8802_dev *dev = data;
  36         struct cx88_core *core = dev->core;
  37         struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;
  38
  39         if (state) {
  40                 vp3054_i2c->state |=  0x0001;   /* SCL high */
  41                 vp3054_i2c->state &= ~0x0100;   /* external pullup */
  42         } else {
  43                 vp3054_i2c->state &= ~0x0001;   /* SCL low */
  44                 vp3054_i2c->state |=  0x0100;   /* drive pin */
  45         }
  46         cx_write(MO_GP0_IO, 0x010000 | vp3054_i2c->state);
  47         cx_read(MO_GP0_IO);
  48 }
  49
  50 static void vp3054_bit_setsda(void *data, int state)
  51 {
  52         struct cx8802_dev *dev = data;
  53         struct cx88_core *core = dev->core;
  54         struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;
  55
  56         if (state) {
  57                 vp3054_i2c->state |=  0x0002;   /* SDA high */
  58                 vp3054_i2c->state &= ~0x0200;   /* tristate pin */
  59         } else {
  60                 vp3054_i2c->state &= ~0x0002;   /* SDA low */
  61                 vp3054_i2c->state |=  0x0200;   /* drive pin */
  62         }
  63         cx_write(MO_GP0_IO, 0x020000 | vp3054_i2c->state);
  64         cx_read(MO_GP0_IO);
  65 }
  66
  67 static int vp3054_bit_getscl(void *data)
  68 {
  69         struct cx8802_dev *dev = data;
  70         struct cx88_core *core = dev->core;
  71         u32 state;
  72
  73         state = cx_read(MO_GP0_IO);
  74         return (state & 0x01) ? 1 : 0;
  75 }
  76
  77 static int vp3054_bit_getsda(void *data)
  78 {
  79         struct cx8802_dev *dev = data;
  80         struct cx88_core *core = dev->core;
  81         u32 state;
  82
  83         state = cx_read(MO_GP0_IO);
  84         return (state & 0x02) ? 1 : 0;
  85 }
  86
  87 /* ----------------------------------------------------------------------- */
  88
  89 static const struct i2c_algo_bit_data vp3054_i2c_algo_template = {
  90         .setsda  = vp3054_bit_setsda,
  91         .setscl  = vp3054_bit_setscl,
  92         .getsda  = vp3054_bit_getsda,
  93         .getscl  = vp3054_bit_getscl,
  94         .udelay  = 16,
  95         .timeout = 200,
  96 };
  97
  98 /* ----------------------------------------------------------------------- */
  99
 100 int vp3054_i2c_probe(struct cx8802_dev *dev)
 101 {
 102         struct cx88_core *core = dev->core;
 103         struct vp3054_i2c_state *vp3054_i2c;
 104         int rc;
 105
 106         if (core->boardnr != CX88_BOARD_DNTV_LIVE_DVB_T_PRO)
 107                 return 0;
 108
 109         vp3054_i2c = kzalloc(sizeof(*vp3054_i2c), GFP_KERNEL);
 110         if (!vp3054_i2c)
 111                 return -ENOMEM;
 112         dev->vp3054 = vp3054_i2c;
 113
 114         vp3054_i2c->algo = vp3054_i2c_algo_template;
 115
 116         vp3054_i2c->adap.dev.parent = &dev->pci->dev;
 117         strlcpy(vp3054_i2c->adap.name, core->name,
 118                 sizeof(vp3054_i2c->adap.name));
 119         vp3054_i2c->adap.owner = THIS_MODULE;
 120         vp3054_i2c->algo.data = dev;
 121         i2c_set_adapdata(&vp3054_i2c->adap, dev);
 122         vp3054_i2c->adap.algo_data = &vp3054_i2c->algo;
 123
 124         vp3054_bit_setscl(dev, 1);
 125         vp3054_bit_setsda(dev, 1);
 126
 127         rc = i2c_bit_add_bus(&vp3054_i2c->adap);
 128         if (rc != 0) {
 129                 pr_err("vp3054_i2c register FAILED\n");
 130
 131                 kfree(dev->vp3054);
 132                 dev->vp3054 = NULL;
 133         }
 134
 135         return rc;
 136 }
 137 EXPORT_SYMBOL(vp3054_i2c_probe);
 138
 139 void vp3054_i2c_remove(struct cx8802_dev *dev)
 140 {
 141         struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;
 142
 143         if (!vp3054_i2c ||
 144             dev->core->boardnr != CX88_BOARD_DNTV_LIVE_DVB_T_PRO)
 145                 return;
 146
 147         i2c_del_adapter(&vp3054_i2c->adap);
 148         kfree(vp3054_i2c);
 149 }
 150 EXPORT_SYMBOL(vp3054_i2c_remove);