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_lock); |
37 | |
38 | static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read, |
39 | u16 command, int flags, u8 *data) |
40 | { |
41 | int i, ret = -EIO; |
42 | u16 val; |
43 | |
44 | if (go->status == STATUS_SHUTDOWN) |
45 | return -ENODEV; |
46 | |
47 | #ifdef GO7007_I2C_DEBUG |
48 | if (read) |
49 | dev_dbg(go->dev, "go7007-i2c: reading 0x%02x on 0x%02x\n" , |
50 | command, addr); |
51 | else |
52 | dev_dbg(go->dev, |
53 | "go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n" , |
54 | *data, command, addr); |
55 | #endif |
56 | |
57 | mutex_lock(&go->hw_lock); |
58 | |
59 | if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) { |
60 | /* Bridge the I2C port on this GO7007 to the shared bus */ |
61 | mutex_lock(&adlink_mpg24_i2c_lock); |
62 | go7007_write_addr(go, 0x3c82, 0x0020); |
63 | } |
64 | |
65 | /* Wait for I2C adapter to be ready */ |
66 | for (i = 0; i < 10; ++i) { |
67 | if (go7007_read_addr(go, STATUS_REG_ADDR, data: &val) < 0) |
68 | goto i2c_done; |
69 | if (!(val & I2C_STATE_MASK)) |
70 | break; |
71 | msleep(msecs: 100); |
72 | } |
73 | if (i == 10) { |
74 | dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n" ); |
75 | goto i2c_done; |
76 | } |
77 | |
78 | /* Set target register (command) */ |
79 | go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags); |
80 | go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command); |
81 | |
82 | /* If we're writing, send the data and target address and we're done */ |
83 | if (!read) { |
84 | go7007_write_addr(go, I2C_DATA_REG_ADDR, *data); |
85 | go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR, |
86 | (addr << 9) | (command >> 8)); |
87 | ret = 0; |
88 | goto i2c_done; |
89 | } |
90 | |
91 | /* Otherwise, we're reading. First clear i2c_rx_data_rdy. */ |
92 | if (go7007_read_addr(go, I2C_DATA_REG_ADDR, data: &val) < 0) |
93 | goto i2c_done; |
94 | |
95 | /* Send the target address plus read flag */ |
96 | go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR, |
97 | (addr << 9) | 0x0100 | (command >> 8)); |
98 | |
99 | /* Wait for i2c_rx_data_rdy */ |
100 | for (i = 0; i < 10; ++i) { |
101 | if (go7007_read_addr(go, STATUS_REG_ADDR, data: &val) < 0) |
102 | goto i2c_done; |
103 | if (val & I2C_READ_READY_MASK) |
104 | break; |
105 | msleep(msecs: 100); |
106 | } |
107 | if (i == 10) { |
108 | dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n" ); |
109 | goto i2c_done; |
110 | } |
111 | |
112 | /* Retrieve the read byte */ |
113 | if (go7007_read_addr(go, I2C_DATA_REG_ADDR, data: &val) < 0) |
114 | goto i2c_done; |
115 | *data = val; |
116 | ret = 0; |
117 | |
118 | i2c_done: |
119 | if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) { |
120 | /* Isolate the I2C port on this GO7007 from the shared bus */ |
121 | go7007_write_addr(go, 0x3c82, 0x0000); |
122 | mutex_unlock(lock: &adlink_mpg24_i2c_lock); |
123 | } |
124 | mutex_unlock(lock: &go->hw_lock); |
125 | return ret; |
126 | } |
127 | |
128 | static int go7007_smbus_xfer(struct i2c_adapter *adapter, u16 addr, |
129 | unsigned short flags, char read_write, |
130 | u8 command, int size, union i2c_smbus_data *data) |
131 | { |
132 | struct go7007 *go = i2c_get_adapdata(adap: adapter); |
133 | |
134 | if (size != I2C_SMBUS_BYTE_DATA) |
135 | return -EIO; |
136 | return go7007_i2c_xfer(go, addr, read: read_write == I2C_SMBUS_READ, command, |
137 | flags: flags & I2C_CLIENT_SCCB ? 0x10 : 0x00, data: &data->byte); |
138 | } |
139 | |
140 | /* VERY LIMITED I2C master xfer function -- only needed because the |
141 | * SMBus functions only support 8-bit commands and the SAA7135 uses |
142 | * 16-bit commands. The I2C interface on the GO7007, as limited as |
143 | * it is, does support this mode. */ |
144 | |
145 | static int go7007_i2c_master_xfer(struct i2c_adapter *adapter, |
146 | struct i2c_msg msgs[], int num) |
147 | { |
148 | struct go7007 *go = i2c_get_adapdata(adap: adapter); |
149 | int i; |
150 | |
151 | for (i = 0; i < num; ++i) { |
152 | /* We can only do two things here -- write three bytes, or |
153 | * write two bytes and read one byte. */ |
154 | if (msgs[i].len == 2) { |
155 | if (i + 1 == num || msgs[i].addr != msgs[i + 1].addr || |
156 | (msgs[i].flags & I2C_M_RD) || |
157 | !(msgs[i + 1].flags & I2C_M_RD) || |
158 | msgs[i + 1].len != 1) |
159 | return -EIO; |
160 | if (go7007_i2c_xfer(go, addr: msgs[i].addr, read: 1, |
161 | command: (msgs[i].buf[0] << 8) | msgs[i].buf[1], |
162 | flags: 0x01, data: &msgs[i + 1].buf[0]) < 0) |
163 | return -EIO; |
164 | ++i; |
165 | } else if (msgs[i].len == 3) { |
166 | if (msgs[i].flags & I2C_M_RD) |
167 | return -EIO; |
168 | if (go7007_i2c_xfer(go, addr: msgs[i].addr, read: 0, |
169 | command: (msgs[i].buf[0] << 8) | msgs[i].buf[1], |
170 | flags: 0x01, data: &msgs[i].buf[2]) < 0) |
171 | return -EIO; |
172 | } else |
173 | return -EIO; |
174 | } |
175 | |
176 | return num; |
177 | } |
178 | |
179 | static u32 go7007_functionality(struct i2c_adapter *adapter) |
180 | { |
181 | return I2C_FUNC_SMBUS_BYTE_DATA; |
182 | } |
183 | |
184 | static const struct i2c_algorithm go7007_algo = { |
185 | .smbus_xfer = go7007_smbus_xfer, |
186 | .master_xfer = go7007_i2c_master_xfer, |
187 | .functionality = go7007_functionality, |
188 | }; |
189 | |
190 | static struct i2c_adapter go7007_adap_templ = { |
191 | .owner = THIS_MODULE, |
192 | .name = "WIS GO7007SB" , |
193 | .algo = &go7007_algo, |
194 | }; |
195 | |
196 | int go7007_i2c_init(struct go7007 *go) |
197 | { |
198 | memcpy(&go->i2c_adapter, &go7007_adap_templ, |
199 | sizeof(go7007_adap_templ)); |
200 | go->i2c_adapter.dev.parent = go->dev; |
201 | i2c_set_adapdata(adap: &go->i2c_adapter, data: go); |
202 | if (i2c_add_adapter(adap: &go->i2c_adapter) < 0) { |
203 | dev_err(go->dev, |
204 | "go7007-i2c: error: i2c_add_adapter failed\n" ); |
205 | return -1; |
206 | } |
207 | return 0; |
208 | } |
209 | |