1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2005-2006 Micronas USA Inc.
4 */
5
6 #include <linux/module.h>
7 #include <linux/delay.h>
8 #include <linux/sched.h>
9 #include <linux/list.h>
10 #include <linux/unistd.h>
11 #include <linux/time.h>
12 #include <linux/device.h>
13 #include <linux/i2c.h>
14 #include <linux/mutex.h>
15 #include <linux/uaccess.h>
16
17 #include "go7007-priv.h"
18
19 /********************* Driver for on-board I2C adapter *********************/
20
21 /* #define GO7007_I2C_DEBUG */
22
23 #define SPI_I2C_ADDR_BASE 0x1400
24 #define STATUS_REG_ADDR (SPI_I2C_ADDR_BASE + 0x2)
25 #define I2C_CTRL_REG_ADDR (SPI_I2C_ADDR_BASE + 0x6)
26 #define I2C_DEV_UP_ADDR_REG_ADDR (SPI_I2C_ADDR_BASE + 0x7)
27 #define I2C_LO_ADDR_REG_ADDR (SPI_I2C_ADDR_BASE + 0x8)
28 #define I2C_DATA_REG_ADDR (SPI_I2C_ADDR_BASE + 0x9)
29 #define I2C_CLKFREQ_REG_ADDR (SPI_I2C_ADDR_BASE + 0xa)
30
31 #define I2C_STATE_MASK 0x0007
32 #define I2C_READ_READY_MASK 0x0008
33
34 /* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs
35 * on the Adlink PCI-MPG24, so access is shared between all of them. */
36 static DEFINE_MUTEX(adlink_mpg24_i2c_mutex);
37
adlink_mpg24_i2c_lock(struct go7007 * go)38 static inline void adlink_mpg24_i2c_lock(struct go7007 *go)
39 {
40 /* Bridge the I2C port on this GO7007 to the shared bus */
41 mutex_lock(&adlink_mpg24_i2c_mutex);
42 go7007_write_addr(go, 0x3c82, 0x0020);
43 }
44
adlink_mpg24_i2c_unlock(struct go7007 * go)45 static inline void adlink_mpg24_i2c_unlock(struct go7007 *go)
46 {
47 /* Isolate the I2C port on this GO7007 from the shared bus */
48 go7007_write_addr(go, 0x3c82, 0x0000);
49 mutex_unlock(&adlink_mpg24_i2c_mutex);
50 }
51
go7007_i2c_xfer(struct go7007 * go,u16 addr,int read,u16 command,int flags,u8 * data)52 static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read,
53 u16 command, int flags, u8 *data)
54 {
55 int i, ret = -EIO;
56 u16 val;
57
58 if (go->status == STATUS_SHUTDOWN)
59 return -ENODEV;
60
61 #ifdef GO7007_I2C_DEBUG
62 if (read)
63 dev_dbg(go->dev, "go7007-i2c: reading 0x%02x on 0x%02x\n",
64 command, addr);
65 else
66 dev_dbg(go->dev,
67 "go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n",
68 *data, command, addr);
69 #endif
70
71 mutex_lock(&go->hw_lock);
72
73 if (go->board_id == GO7007_BOARDID_ADLINK_MPG24)
74 adlink_mpg24_i2c_lock(go);
75
76 /* Wait for I2C adapter to be ready */
77 for (i = 0; i < 10; ++i) {
78 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
79 goto i2c_done;
80 if (!(val & I2C_STATE_MASK))
81 break;
82 msleep(100);
83 }
84 if (i == 10) {
85 dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n");
86 goto i2c_done;
87 }
88
89 /* Set target register (command) */
90 go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags);
91 go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command);
92
93 /* If we're writing, send the data and target address and we're done */
94 if (!read) {
95 go7007_write_addr(go, I2C_DATA_REG_ADDR, *data);
96 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
97 (addr << 9) | (command >> 8));
98 ret = 0;
99 goto i2c_done;
100 }
101
102 /* Otherwise, we're reading. First clear i2c_rx_data_rdy. */
103 if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
104 goto i2c_done;
105
106 /* Send the target address plus read flag */
107 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR,
108 (addr << 9) | 0x0100 | (command >> 8));
109
110 /* Wait for i2c_rx_data_rdy */
111 for (i = 0; i < 10; ++i) {
112 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0)
113 goto i2c_done;
114 if (val & I2C_READ_READY_MASK)
115 break;
116 msleep(100);
117 }
118 if (i == 10) {
119 dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n");
120 goto i2c_done;
121 }
122
123 /* Retrieve the read byte */
124 if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0)
125 goto i2c_done;
126 *data = val;
127 ret = 0;
128
129 i2c_done:
130 if (go->board_id == GO7007_BOARDID_ADLINK_MPG24)
131 adlink_mpg24_i2c_unlock(go);
132 mutex_unlock(&go->hw_lock);
133 return ret;
134 }
135
go7007_smbus_xfer(struct i2c_adapter * adapter,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)136 static 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
go7007_i2c_master_xfer(struct i2c_adapter * adapter,struct i2c_msg msgs[],int num)153 static 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 (go7007_i2c_xfer(go, msgs[i].addr, 0,
177 (msgs[i].buf[0] << 8) | msgs[i].buf[1],
178 0x01, &msgs[i].buf[2]) < 0)
179 return -EIO;
180 } else
181 return -EIO;
182 }
183
184 return num;
185 }
186
go7007_functionality(struct i2c_adapter * adapter)187 static u32 go7007_functionality(struct i2c_adapter *adapter)
188 {
189 return I2C_FUNC_SMBUS_BYTE_DATA;
190 }
191
192 static const struct i2c_algorithm go7007_algo = {
193 .smbus_xfer = go7007_smbus_xfer,
194 .master_xfer = go7007_i2c_master_xfer,
195 .functionality = go7007_functionality,
196 };
197
198 static struct i2c_adapter go7007_adap_templ = {
199 .owner = THIS_MODULE,
200 .name = "WIS GO7007SB",
201 .algo = &go7007_algo,
202 };
203
go7007_i2c_init(struct go7007 * go)204 int go7007_i2c_init(struct go7007 *go)
205 {
206 memcpy(&go->i2c_adapter, &go7007_adap_templ,
207 sizeof(go7007_adap_templ));
208 go->i2c_adapter.dev.parent = go->dev;
209 i2c_set_adapdata(&go->i2c_adapter, go);
210 if (i2c_add_adapter(&go->i2c_adapter) < 0) {
211 dev_err(go->dev,
212 "go7007-i2c: error: i2c_add_adapter failed\n");
213 return -1;
214 }
215 return 0;
216 }
217