drivers/media/pci/saa7164/saa7164-i2c.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Driver for the NXP SAA7164 PCIe bridge
   4  *
   5  *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/moduleparam.h>
  10 #include <linux/init.h>
  11 #include <linux/delay.h>
  12 #include <linux/io.h>
  13
  14 #include "saa7164.h"
  15
  16 static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
  17 {
  18         struct saa7164_i2c *bus = i2c_adap->algo_data;
  19         struct saa7164_dev *dev = bus->dev;
  20         int i, retval = 0;
  21
  22         dprintk(DBGLVL_I2C, "%s(num = %d)\n", __func__, num);
  23
  24         for (i = 0 ; i < num; i++) {
  25                 dprintk(DBGLVL_I2C, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
  26                         __func__, num, msgs[i].addr, msgs[i].len);
  27                 if (msgs[i].flags & I2C_M_RD) {
  28                         retval = saa7164_api_i2c_read(bus,
  29                                 msgs[i].addr,
  30                                 0 /* reglen */,
  31                                 NULL /* reg */, msgs[i].len, msgs[i].buf);
  32                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
  33                            msgs[i].addr == msgs[i + 1].addr) {
  34                         /* write then read from same address */
  35
  36                         retval = saa7164_api_i2c_read(bus, msgs[i].addr,
  37                                 msgs[i].len, msgs[i].buf,
  38                                 msgs[i+1].len, msgs[i+1].buf
  39                                 );
  40
  41                         i++;
  42
  43                         if (retval < 0)
  44                                 goto err;
  45                 } else {
  46                         /* write */
  47                         retval = saa7164_api_i2c_write(bus, msgs[i].addr,
  48                                 msgs[i].len, msgs[i].buf);
  49                 }
  50                 if (retval < 0)
  51                         goto err;
  52         }
  53         return num;
  54
  55 err:
  56         return retval;
  57 }
  58
  59 static u32 saa7164_functionality(struct i2c_adapter *adap)
  60 {
  61         return I2C_FUNC_I2C;
  62 }
  63
  64 static const struct i2c_algorithm saa7164_i2c_algo_template = {
  65         .master_xfer    = i2c_xfer,
  66         .functionality  = saa7164_functionality,
  67 };
  68
  69 /* ----------------------------------------------------------------------- */
  70
  71 static const struct i2c_adapter saa7164_i2c_adap_template = {
  72         .name              = "saa7164",
  73         .owner             = THIS_MODULE,
  74         .algo              = &saa7164_i2c_algo_template,
  75 };
  76
  77 static const struct i2c_client saa7164_i2c_client_template = {
  78         .name   = "saa7164 internal",
  79 };
  80
  81 int saa7164_i2c_register(struct saa7164_i2c *bus)
  82 {
  83         struct saa7164_dev *dev = bus->dev;
  84
  85         dprintk(DBGLVL_I2C, "%s(bus = %d)\n", __func__, bus->nr);
  86
  87         bus->i2c_adap = saa7164_i2c_adap_template;
  88         bus->i2c_client = saa7164_i2c_client_template;
  89
  90         bus->i2c_adap.dev.parent = &dev->pci->dev;
  91
  92         strscpy(bus->i2c_adap.name, bus->dev->name,
  93                 sizeof(bus->i2c_adap.name));
  94
  95         bus->i2c_adap.algo_data = bus;
  96         i2c_set_adapdata(&bus->i2c_adap, bus);
  97         i2c_add_adapter(&bus->i2c_adap);
  98
  99         bus->i2c_client.adapter = &bus->i2c_adap;
 100
 101         if (0 != bus->i2c_rc)
 102                 printk(KERN_ERR "%s: i2c bus %d register FAILED\n",
 103                         dev->name, bus->nr);
 104
 105         return bus->i2c_rc;
 106 }
 107
 108 int saa7164_i2c_unregister(struct saa7164_i2c *bus)
 109 {
 110         i2c_del_adapter(&bus->i2c_adap);
 111         return 0;
 112 }