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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   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
  10 #include "cx88.h"
  11 #include "cx88-vp3054-i2c.h"
  12
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/init.h>
  16 #include <linux/io.h>
  17
  18 MODULE_DESCRIPTION("driver for cx2388x VP3054 design");
  19 MODULE_AUTHOR("Chris Pascoe <c.pascoe@itee.uq.edu.au>");
  20 MODULE_LICENSE("GPL");
  21
  22 /* ----------------------------------------------------------------------- */
  23
  24 static void vp3054_bit_setscl(void *data, int state)
  25 {
  26         struct cx8802_dev *dev = data;
  27         struct cx88_core *core = dev->core;
  28         struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;
  29
  30         if (state) {
  31                 vp3054_i2c->state |=  0x0001;   /* SCL high */
  32                 vp3054_i2c->state &= ~0x0100;   /* external pullup */
  33         } else {
  34                 vp3054_i2c->state &= ~0x0001;   /* SCL low */
  35                 vp3054_i2c->state |=  0x0100;   /* drive pin */
  36         }
  37         cx_write(MO_GP0_IO, 0x010000 | vp3054_i2c->state);
  38         cx_read(MO_GP0_IO);
  39 }
  40
  41 static void vp3054_bit_setsda(void *data, int state)
  42 {
  43         struct cx8802_dev *dev = data;
  44         struct cx88_core *core = dev->core;
  45         struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;
  46
  47         if (state) {
  48                 vp3054_i2c->state |=  0x0002;   /* SDA high */
  49                 vp3054_i2c->state &= ~0x0200;   /* tristate pin */
  50         } else {
  51                 vp3054_i2c->state &= ~0x0002;   /* SDA low */
  52                 vp3054_i2c->state |=  0x0200;   /* drive pin */
  53         }
  54         cx_write(MO_GP0_IO, 0x020000 | vp3054_i2c->state);
  55         cx_read(MO_GP0_IO);
  56 }
  57
  58 static int vp3054_bit_getscl(void *data)
  59 {
  60         struct cx8802_dev *dev = data;
  61         struct cx88_core *core = dev->core;
  62         u32 state;
  63
  64         state = cx_read(MO_GP0_IO);
  65         return (state & 0x01) ? 1 : 0;
  66 }
  67
  68 static int vp3054_bit_getsda(void *data)
  69 {
  70         struct cx8802_dev *dev = data;
  71         struct cx88_core *core = dev->core;
  72         u32 state;
  73
  74         state = cx_read(MO_GP0_IO);
  75         return (state & 0x02) ? 1 : 0;
  76 }
  77
  78 /* ----------------------------------------------------------------------- */
  79
  80 static const struct i2c_algo_bit_data vp3054_i2c_algo_template = {
  81         .setsda  = vp3054_bit_setsda,
  82         .setscl  = vp3054_bit_setscl,
  83         .getsda  = vp3054_bit_getsda,
  84         .getscl  = vp3054_bit_getscl,
  85         .udelay  = 16,
  86         .timeout = 200,
  87 };
  88
  89 /* ----------------------------------------------------------------------- */
  90
  91 int vp3054_i2c_probe(struct cx8802_dev *dev)
  92 {
  93         struct cx88_core *core = dev->core;
  94         struct vp3054_i2c_state *vp3054_i2c;
  95         int rc;
  96
  97         if (core->boardnr != CX88_BOARD_DNTV_LIVE_DVB_T_PRO)
  98                 return 0;
  99
 100         vp3054_i2c = kzalloc(sizeof(*vp3054_i2c), GFP_KERNEL);
 101         if (!vp3054_i2c)
 102                 return -ENOMEM;
 103         dev->vp3054 = vp3054_i2c;
 104
 105         vp3054_i2c->algo = vp3054_i2c_algo_template;
 106
 107         vp3054_i2c->adap.dev.parent = &dev->pci->dev;
 108         strscpy(vp3054_i2c->adap.name, core->name,
 109                 sizeof(vp3054_i2c->adap.name));
 110         vp3054_i2c->adap.owner = THIS_MODULE;
 111         vp3054_i2c->algo.data = dev;
 112         i2c_set_adapdata(&vp3054_i2c->adap, dev);
 113         vp3054_i2c->adap.algo_data = &vp3054_i2c->algo;
 114
 115         vp3054_bit_setscl(dev, 1);
 116         vp3054_bit_setsda(dev, 1);
 117
 118         rc = i2c_bit_add_bus(&vp3054_i2c->adap);
 119         if (rc != 0) {
 120                 pr_err("vp3054_i2c register FAILED\n");
 121
 122                 kfree(dev->vp3054);
 123                 dev->vp3054 = NULL;
 124         }
 125
 126         return rc;
 127 }
 128 EXPORT_SYMBOL(vp3054_i2c_probe);
 129
 130 void vp3054_i2c_remove(struct cx8802_dev *dev)
 131 {
 132         struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;
 133
 134         if (!vp3054_i2c ||
 135             dev->core->boardnr != CX88_BOARD_DNTV_LIVE_DVB_T_PRO)
 136                 return;
 137
 138         i2c_del_adapter(&vp3054_i2c->adap);
 139         kfree(vp3054_i2c);
 140 }
 141 EXPORT_SYMBOL(vp3054_i2c_remove);