1/*
2 * Copyright (C) 2005-2006 Micronas USA Inc.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License (Version 2) as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * GNU General Public License for more details.
12 */
13
14#include <linux/module.h>
15#include <linux/delay.h>
16#include <linux/sched.h>
17#include <linux/list.h>
18#include <linux/unistd.h>
19#include <linux/time.h>
20#include <linux/device.h>
21#include <linux/i2c.h>
22#include <linux/mutex.h>
23#include <linux/uaccess.h>
24
25#include "go7007-priv.h"
26
27/********************* Driver for on-board I2C adapter *********************/
28
29/* #define GO7007_I2C_DEBUG */
30
31#define SPI_I2C_ADDR_BASE		0x1400
32#define STATUS_REG_ADDR			(SPI_I2C_ADDR_BASE + 0x2)
33#define I2C_CTRL_REG_ADDR		(SPI_I2C_ADDR_BASE + 0x6)
34#define I2C_DEV_UP_ADDR_REG_ADDR	(SPI_I2C_ADDR_BASE + 0x7)
35#define I2C_LO_ADDR_REG_ADDR		(SPI_I2C_ADDR_BASE + 0x8)
36#define I2C_DATA_REG_ADDR		(SPI_I2C_ADDR_BASE + 0x9)
37#define I2C_CLKFREQ_REG_ADDR		(SPI_I2C_ADDR_BASE + 0xa)
38
39#define I2C_STATE_MASK			0x0007
40#define I2C_READ_READY_MASK		0x0008
41
42/* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs
43 * on the Adlink PCI-MPG24, so access is shared between all of them. */
44static DEFINE_MUTEX(adlink_mpg24_i2c_lock);
45
46static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read,
47		u16 command, int flags, u8 *data)
48{
49	int i, ret = -EIO;
50	u16 val;
51
52	if (go->status == STATUS_SHUTDOWN)
53		return -ENODEV;
54
55#ifdef GO7007_I2C_DEBUG
56	if (read)
57		dev_dbg(go->dev, "go7007-i2c: reading 0x%02x on 0x%02x\n",
58			command, addr);
59	else
60		dev_dbg(go->dev,
61			"go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n",
62			*data, command, addr);
63#endif
64
65	mutex_lock(&go->hw_lock);
66
67	if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
68		/* Bridge the I2C port on this GO7007 to the shared bus */
69		mutex_lock(&adlink_mpg24_i2c_lock);
70		go7007_write_addr(go, 0x3c82, 0x0020);
71	}
72
73	/* Wait for I2C adapter to be ready */
74	for (i = 0; i < 10; ++i) {
75		if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
76			goto i2c_done;
77		if (!(val & I2C_STATE_MASK))
78			break;
79		msleep(100);
80	}
81	if (i == 10) {
82		dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n");
83		goto i2c_done;
84	}
85
86	/* Set target register (command) */
87	go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags);
88	go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command);
89
90	/* If we're writing, send the data and target address and we're done */
91	if (!read) {
92		go7007_write_addr(go, I2C_DATA_REG_ADDR, *data);
93		go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
94					(addr << 9) | (command >> 8));
95		ret = 0;
96		goto i2c_done;
97	}
98
99	/* Otherwise, we're reading.  First clear i2c_rx_data_rdy. */
100	if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
101		goto i2c_done;
102
103	/* Send the target address plus read flag */
104	go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
105			(addr << 9) | 0x0100 | (command >> 8));
106
107	/* Wait for i2c_rx_data_rdy */
108	for (i = 0; i < 10; ++i) {
109		if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
110			goto i2c_done;
111		if (val & I2C_READ_READY_MASK)
112			break;
113		msleep(100);
114	}
115	if (i == 10) {
116		dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n");
117		goto i2c_done;
118	}
119
120	/* Retrieve the read byte */
121	if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
122		goto i2c_done;
123	*data = val;
124	ret = 0;
125
126i2c_done:
127	if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) {
128		/* Isolate the I2C port on this GO7007 from the shared bus */
129		go7007_write_addr(go, 0x3c82, 0x0000);
130		mutex_unlock(&adlink_mpg24_i2c_lock);
131	}
132	mutex_unlock(&go->hw_lock);
133	return ret;
134}
135
136static int go7007_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
137		unsigned short flags, char read_write,
138		u8 command, int size, union i2c_smbus_data *data)
139{
140	struct go7007 *go = i2c_get_adapdata(adapter);
141
142	if (size != I2C_SMBUS_BYTE_DATA)
143		return -EIO;
144	return go7007_i2c_xfer(go, addr, read_write == I2C_SMBUS_READ, command,
145			flags & I2C_CLIENT_SCCB ? 0x10 : 0x00, &data->byte);
146}
147
148/* VERY LIMITED I2C master xfer function -- only needed because the
149 * SMBus functions only support 8-bit commands and the SAA7135 uses
150 * 16-bit commands.  The I2C interface on the GO7007, as limited as
151 * it is, does support this mode. */
152
153static int go7007_i2c_master_xfer(struct i2c_adapter *adapter,
154					struct i2c_msg msgs[], int num)
155{
156	struct go7007 *go = i2c_get_adapdata(adapter);
157	int i;
158
159	for (i = 0; i < num; ++i) {
160		/* We can only do two things here -- write three bytes, or
161		 * write two bytes and read one byte. */
162		if (msgs[i].len == 2) {
163			if (i + 1 == num || msgs[i].addr != msgs[i + 1].addr ||
164					(msgs[i].flags & I2C_M_RD) ||
165					!(msgs[i + 1].flags & I2C_M_RD) ||
166					msgs[i + 1].len != 1)
167				return -EIO;
168			if (go7007_i2c_xfer(go, msgs[i].addr, 1,
169					(msgs[i].buf[0] << 8) | msgs[i].buf[1],
170					0x01, &msgs[i + 1].buf[0]) < 0)
171				return -EIO;
172			++i;
173		} else if (msgs[i].len == 3) {
174			if (msgs[i].flags & I2C_M_RD)
175				return -EIO;
176			if (msgs[i].len != 3)
177				return -EIO;
178			if (go7007_i2c_xfer(go, msgs[i].addr, 0,
179					(msgs[i].buf[0] << 8) | msgs[i].buf[1],
180					0x01, &msgs[i].buf[2]) < 0)
181				return -EIO;
182		} else
183			return -EIO;
184	}
185
186	return num;
187}
188
189static u32 go7007_functionality(struct i2c_adapter *adapter)
190{
191	return I2C_FUNC_SMBUS_BYTE_DATA;
192}
193
194static struct i2c_algorithm go7007_algo = {
195	.smbus_xfer	= go7007_smbus_xfer,
196	.master_xfer	= go7007_i2c_master_xfer,
197	.functionality	= go7007_functionality,
198};
199
200static struct i2c_adapter go7007_adap_templ = {
201	.owner			= THIS_MODULE,
202	.name			= "WIS GO7007SB",
203	.algo			= &go7007_algo,
204};
205
206int go7007_i2c_init(struct go7007 *go)
207{
208	memcpy(&go->i2c_adapter, &go7007_adap_templ,
209			sizeof(go7007_adap_templ));
210	go->i2c_adapter.dev.parent = go->dev;
211	i2c_set_adapdata(&go->i2c_adapter, go);
212	if (i2c_add_adapter(&go->i2c_adapter) < 0) {
213		dev_err(go->dev,
214			"go7007-i2c: error: i2c_add_adapter failed\n");
215		return -1;
216	}
217	return 0;
218}
219