diff options
author | Dave Airlie <airlied@redhat.com> | 2009-12-07 22:52:41 -0500 |
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committer | Dave Airlie <airlied@redhat.com> | 2009-12-07 22:52:41 -0500 |
commit | 1bd049fa895f9c6743f38b52ce14775f5a31ea63 (patch) | |
tree | cb9163ac1c20f7fbdbde42eaab8013d0c3734aed /drivers/gpu/drm/drm_dp_i2c_helper.c | |
parent | 22763c5cf3690a681551162c15d34d935308c8d7 (diff) | |
parent | b0a007dc27d8d3ff3db07b3ea997323d9330f770 (diff) |
Merge branch 'drm-core-next' into drm-linus
Bring all core drm changes into 2.6.32 tree and resolve
the conflict that occurs.
Conflicts:
drivers/gpu/drm/drm_fb_helper.c
Diffstat (limited to 'drivers/gpu/drm/drm_dp_i2c_helper.c')
-rw-r--r-- | drivers/gpu/drm/drm_dp_i2c_helper.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_dp_i2c_helper.c b/drivers/gpu/drm/drm_dp_i2c_helper.c new file mode 100644 index 000000000000..f1c7c856e9db --- /dev/null +++ b/drivers/gpu/drm/drm_dp_i2c_helper.c | |||
@@ -0,0 +1,209 @@ | |||
1 | /* | ||
2 | * Copyright © 2009 Keith Packard | ||
3 | * | ||
4 | * Permission to use, copy, modify, distribute, and sell this software and its | ||
5 | * documentation for any purpose is hereby granted without fee, provided that | ||
6 | * the above copyright notice appear in all copies and that both that copyright | ||
7 | * notice and this permission notice appear in supporting documentation, and | ||
8 | * that the name of the copyright holders not be used in advertising or | ||
9 | * publicity pertaining to distribution of the software without specific, | ||
10 | * written prior permission. The copyright holders make no representations | ||
11 | * about the suitability of this software for any purpose. It is provided "as | ||
12 | * is" without express or implied warranty. | ||
13 | * | ||
14 | * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, | ||
15 | * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO | ||
16 | * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR | ||
17 | * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, | ||
18 | * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER | ||
19 | * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE | ||
20 | * OF THIS SOFTWARE. | ||
21 | */ | ||
22 | |||
23 | #include <linux/kernel.h> | ||
24 | #include <linux/module.h> | ||
25 | #include <linux/delay.h> | ||
26 | #include <linux/slab.h> | ||
27 | #include <linux/init.h> | ||
28 | #include <linux/errno.h> | ||
29 | #include <linux/sched.h> | ||
30 | #include <linux/i2c.h> | ||
31 | #include "drm_dp_helper.h" | ||
32 | #include "drmP.h" | ||
33 | |||
34 | /* Run a single AUX_CH I2C transaction, writing/reading data as necessary */ | ||
35 | static int | ||
36 | i2c_algo_dp_aux_transaction(struct i2c_adapter *adapter, int mode, | ||
37 | uint8_t write_byte, uint8_t *read_byte) | ||
38 | { | ||
39 | struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; | ||
40 | int ret; | ||
41 | |||
42 | ret = (*algo_data->aux_ch)(adapter, mode, | ||
43 | write_byte, read_byte); | ||
44 | return ret; | ||
45 | } | ||
46 | |||
47 | /* | ||
48 | * I2C over AUX CH | ||
49 | */ | ||
50 | |||
51 | /* | ||
52 | * Send the address. If the I2C link is running, this 'restarts' | ||
53 | * the connection with the new address, this is used for doing | ||
54 | * a write followed by a read (as needed for DDC) | ||
55 | */ | ||
56 | static int | ||
57 | i2c_algo_dp_aux_address(struct i2c_adapter *adapter, u16 address, bool reading) | ||
58 | { | ||
59 | struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; | ||
60 | int mode = MODE_I2C_START; | ||
61 | int ret; | ||
62 | |||
63 | if (reading) | ||
64 | mode |= MODE_I2C_READ; | ||
65 | else | ||
66 | mode |= MODE_I2C_WRITE; | ||
67 | algo_data->address = address; | ||
68 | algo_data->running = true; | ||
69 | ret = i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL); | ||
70 | return ret; | ||
71 | } | ||
72 | |||
73 | /* | ||
74 | * Stop the I2C transaction. This closes out the link, sending | ||
75 | * a bare address packet with the MOT bit turned off | ||
76 | */ | ||
77 | static void | ||
78 | i2c_algo_dp_aux_stop(struct i2c_adapter *adapter, bool reading) | ||
79 | { | ||
80 | struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; | ||
81 | int mode = MODE_I2C_STOP; | ||
82 | |||
83 | if (reading) | ||
84 | mode |= MODE_I2C_READ; | ||
85 | else | ||
86 | mode |= MODE_I2C_WRITE; | ||
87 | if (algo_data->running) { | ||
88 | (void) i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL); | ||
89 | algo_data->running = false; | ||
90 | } | ||
91 | } | ||
92 | |||
93 | /* | ||
94 | * Write a single byte to the current I2C address, the | ||
95 | * the I2C link must be running or this returns -EIO | ||
96 | */ | ||
97 | static int | ||
98 | i2c_algo_dp_aux_put_byte(struct i2c_adapter *adapter, u8 byte) | ||
99 | { | ||
100 | struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; | ||
101 | int ret; | ||
102 | |||
103 | if (!algo_data->running) | ||
104 | return -EIO; | ||
105 | |||
106 | ret = i2c_algo_dp_aux_transaction(adapter, MODE_I2C_WRITE, byte, NULL); | ||
107 | return ret; | ||
108 | } | ||
109 | |||
110 | /* | ||
111 | * Read a single byte from the current I2C address, the | ||
112 | * I2C link must be running or this returns -EIO | ||
113 | */ | ||
114 | static int | ||
115 | i2c_algo_dp_aux_get_byte(struct i2c_adapter *adapter, u8 *byte_ret) | ||
116 | { | ||
117 | struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; | ||
118 | int ret; | ||
119 | |||
120 | if (!algo_data->running) | ||
121 | return -EIO; | ||
122 | |||
123 | ret = i2c_algo_dp_aux_transaction(adapter, MODE_I2C_READ, 0, byte_ret); | ||
124 | return ret; | ||
125 | } | ||
126 | |||
127 | static int | ||
128 | i2c_algo_dp_aux_xfer(struct i2c_adapter *adapter, | ||
129 | struct i2c_msg *msgs, | ||
130 | int num) | ||
131 | { | ||
132 | int ret = 0; | ||
133 | bool reading = false; | ||
134 | int m; | ||
135 | int b; | ||
136 | |||
137 | for (m = 0; m < num; m++) { | ||
138 | u16 len = msgs[m].len; | ||
139 | u8 *buf = msgs[m].buf; | ||
140 | reading = (msgs[m].flags & I2C_M_RD) != 0; | ||
141 | ret = i2c_algo_dp_aux_address(adapter, msgs[m].addr, reading); | ||
142 | if (ret < 0) | ||
143 | break; | ||
144 | if (reading) { | ||
145 | for (b = 0; b < len; b++) { | ||
146 | ret = i2c_algo_dp_aux_get_byte(adapter, &buf[b]); | ||
147 | if (ret < 0) | ||
148 | break; | ||
149 | } | ||
150 | } else { | ||
151 | for (b = 0; b < len; b++) { | ||
152 | ret = i2c_algo_dp_aux_put_byte(adapter, buf[b]); | ||
153 | if (ret < 0) | ||
154 | break; | ||
155 | } | ||
156 | } | ||
157 | if (ret < 0) | ||
158 | break; | ||
159 | } | ||
160 | if (ret >= 0) | ||
161 | ret = num; | ||
162 | i2c_algo_dp_aux_stop(adapter, reading); | ||
163 | DRM_DEBUG("dp_aux_xfer return %d\n", ret); | ||
164 | return ret; | ||
165 | } | ||
166 | |||
167 | static u32 | ||
168 | i2c_algo_dp_aux_functionality(struct i2c_adapter *adapter) | ||
169 | { | ||
170 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | | ||
171 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | | ||
172 | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | | ||
173 | I2C_FUNC_10BIT_ADDR; | ||
174 | } | ||
175 | |||
176 | static const struct i2c_algorithm i2c_dp_aux_algo = { | ||
177 | .master_xfer = i2c_algo_dp_aux_xfer, | ||
178 | .functionality = i2c_algo_dp_aux_functionality, | ||
179 | }; | ||
180 | |||
181 | static void | ||
182 | i2c_dp_aux_reset_bus(struct i2c_adapter *adapter) | ||
183 | { | ||
184 | (void) i2c_algo_dp_aux_address(adapter, 0, false); | ||
185 | (void) i2c_algo_dp_aux_stop(adapter, false); | ||
186 | |||
187 | } | ||
188 | |||
189 | static int | ||
190 | i2c_dp_aux_prepare_bus(struct i2c_adapter *adapter) | ||
191 | { | ||
192 | adapter->algo = &i2c_dp_aux_algo; | ||
193 | adapter->retries = 3; | ||
194 | i2c_dp_aux_reset_bus(adapter); | ||
195 | return 0; | ||
196 | } | ||
197 | |||
198 | int | ||
199 | i2c_dp_aux_add_bus(struct i2c_adapter *adapter) | ||
200 | { | ||
201 | int error; | ||
202 | |||
203 | error = i2c_dp_aux_prepare_bus(adapter); | ||
204 | if (error) | ||
205 | return error; | ||
206 | error = i2c_add_adapter(adapter); | ||
207 | return error; | ||
208 | } | ||
209 | EXPORT_SYMBOL(i2c_dp_aux_add_bus); | ||