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
 16static 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
 55err:
 56	return retval;
 57}
 58
 59static u32 saa7164_functionality(struct i2c_adapter *adap)
 60{
 61	return I2C_FUNC_I2C;
 62}
 63
 64static const struct i2c_algorithm saa7164_i2c_algo_template = {
 65	.master_xfer	= i2c_xfer,
 66	.functionality	= saa7164_functionality,
 67};
 68
 69/* ----------------------------------------------------------------------- */
 70
 71static const struct i2c_adapter saa7164_i2c_adap_template = {
 72	.name              = "saa7164",
 73	.owner             = THIS_MODULE,
 74	.algo              = &saa7164_i2c_algo_template,
 75};
 76
 77static const struct i2c_client saa7164_i2c_client_template = {
 78	.name	= "saa7164 internal",
 79};
 80
 81int 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
108int saa7164_i2c_unregister(struct saa7164_i2c *bus)
109{
110	i2c_del_adapter(&bus->i2c_adap);
111	return 0;
112}