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

   1 /*
   2
   3     cx88-vp3054-i2c.c  --  support for the secondary I2C bus of the
   4                            DNTV Live! DVB-T Pro (VP-3054), wired as:
   5                            GPIO[0] -> SCL, GPIO[1] -> SDA
   6
   7     (c) 2005 Chris Pascoe <c.pascoe@itee.uq.edu.au>
   8
   9     This program is free software; you can redistribute it and/or modify
  10     it under the terms of the GNU General Public License as published by
  11     the Free Software Foundation; either version 2 of the License, or
  12     (at your option) any later version.
  13
  14     This program is distributed in the hope that it will be useful,
  15     but WITHOUT ANY WARRANTY; without even the implied warranty of
  16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17     GNU General Public License for more details.
  18
  19     You should have received a copy of the GNU General Public License
  20     along with this program; if not, write to the Free Software
  21     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22
  23 */
  24
  25 #include <linux/module.h>
  26 #include <linux/slab.h>
  27 #include <linux/init.h>
  28
  29 #include <asm/io.h>
  30
  31 #include "cx88.h"
  32 #include "cx88-vp3054-i2c.h"
  33
  34 MODULE_DESCRIPTION("driver for cx2388x VP3054 design");
  35 MODULE_AUTHOR("Chris Pascoe <c.pascoe@itee.uq.edu.au>");
  36 MODULE_LICENSE("GPL");
  37
  38 /* ----------------------------------------------------------------------- */
  39
  40 static void vp3054_bit_setscl(void *data, int state)
  41 {
  42         struct cx8802_dev *dev = data;
  43         struct cx88_core *core = dev->core;
  44         struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;
  45
  46         if (state) {
  47                 vp3054_i2c->state |=  0x0001;   /* SCL high */
  48                 vp3054_i2c->state &= ~0x0100;   /* external pullup */
  49         } else {
  50                 vp3054_i2c->state &= ~0x0001;   /* SCL low */
  51                 vp3054_i2c->state |=  0x0100;   /* drive pin */
  52         }
  53         cx_write(MO_GP0_IO, 0x010000 | vp3054_i2c->state);
  54         cx_read(MO_GP0_IO);
  55 }
  56
  57 static void vp3054_bit_setsda(void *data, int state)
  58 {
  59         struct cx8802_dev *dev = data;
  60         struct cx88_core *core = dev->core;
  61         struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;
  62
  63         if (state) {
  64                 vp3054_i2c->state |=  0x0002;   /* SDA high */
  65                 vp3054_i2c->state &= ~0x0200;   /* tristate pin */
  66         } else {
  67                 vp3054_i2c->state &= ~0x0002;   /* SDA low */
  68                 vp3054_i2c->state |=  0x0200;   /* drive pin */
  69         }
  70         cx_write(MO_GP0_IO, 0x020000 | vp3054_i2c->state);
  71         cx_read(MO_GP0_IO);
  72 }
  73
  74 static int vp3054_bit_getscl(void *data)
  75 {
  76         struct cx8802_dev *dev = data;
  77         struct cx88_core *core = dev->core;
  78         u32 state;
  79
  80         state = cx_read(MO_GP0_IO);
  81         return (state & 0x01) ? 1 : 0;
  82 }
  83
  84 static int vp3054_bit_getsda(void *data)
  85 {
  86         struct cx8802_dev *dev = data;
  87         struct cx88_core *core = dev->core;
  88         u32 state;
  89
  90         state = cx_read(MO_GP0_IO);
  91         return (state & 0x02) ? 1 : 0;
  92 }
  93
  94 /* ----------------------------------------------------------------------- */
  95
  96 static const struct i2c_algo_bit_data vp3054_i2c_algo_template = {
  97         .setsda  = vp3054_bit_setsda,
  98         .setscl  = vp3054_bit_setscl,
  99         .getsda  = vp3054_bit_getsda,
 100         .getscl  = vp3054_bit_getscl,
 101         .udelay  = 16,
 102         .timeout = 200,
 103 };
 104
 105 /* ----------------------------------------------------------------------- */
 106
 107 int vp3054_i2c_probe(struct cx8802_dev *dev)
 108 {
 109         struct cx88_core *core = dev->core;
 110         struct vp3054_i2c_state *vp3054_i2c;
 111         int rc;
 112
 113         if (core->boardnr != CX88_BOARD_DNTV_LIVE_DVB_T_PRO)
 114                 return 0;
 115
 116         vp3054_i2c = kzalloc(sizeof(*vp3054_i2c), GFP_KERNEL);
 117         if (vp3054_i2c == NULL)
 118                 return -ENOMEM;
 119         dev->vp3054 = vp3054_i2c;
 120
 121         memcpy(&vp3054_i2c->algo, &vp3054_i2c_algo_template,
 122                sizeof(vp3054_i2c->algo));
 123
 124         vp3054_i2c->adap.dev.parent = &dev->pci->dev;
 125         strlcpy(vp3054_i2c->adap.name, core->name,
 126                 sizeof(vp3054_i2c->adap.name));
 127         vp3054_i2c->adap.owner = THIS_MODULE;
 128         vp3054_i2c->algo.data = dev;
 129         i2c_set_adapdata(&vp3054_i2c->adap, dev);
 130         vp3054_i2c->adap.algo_data = &vp3054_i2c->algo;
 131
 132         vp3054_bit_setscl(dev,1);
 133         vp3054_bit_setsda(dev,1);
 134
 135         rc = i2c_bit_add_bus(&vp3054_i2c->adap);
 136         if (0 != rc) {
 137                 printk("%s: vp3054_i2c register FAILED\n", core->name);
 138
 139                 kfree(dev->vp3054);
 140                 dev->vp3054 = NULL;
 141         }
 142
 143         return rc;
 144 }
 145
 146 void vp3054_i2c_remove(struct cx8802_dev *dev)
 147 {
 148         struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;
 149
 150         if (vp3054_i2c == NULL ||
 151             dev->core->boardnr != CX88_BOARD_DNTV_LIVE_DVB_T_PRO)
 152                 return;
 153
 154         i2c_del_adapter(&vp3054_i2c->adap);
 155         kfree(vp3054_i2c);
 156 }
 157
 158 EXPORT_SYMBOL(vp3054_i2c_probe);
 159 EXPORT_SYMBOL(vp3054_i2c_remove);