1 /*
2  * Copyright 2009 Red Hat Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: Ben Skeggs
23  */
24 #include "priv.h"
25 
26 int
27 nv_rdaux(struct nvkm_i2c_port *port, u32 addr, u8 *data, u8 size)
28 {
29 	struct nvkm_i2c *i2c = nvkm_i2c(port);
30 	if (port->func->aux) {
31 		int ret = i2c->acquire(port, 0);
32 		if (ret == 0) {
33 			ret = port->func->aux(port, true, 9, addr, data, size);
34 			i2c->release(port);
35 		}
36 		return ret;
37 	}
38 	return -ENODEV;
39 }
40 
41 int
42 nv_wraux(struct nvkm_i2c_port *port, u32 addr, u8 *data, u8 size)
43 {
44 	struct nvkm_i2c *i2c = nvkm_i2c(port);
45 	if (port->func->aux) {
46 		int ret = i2c->acquire(port, 0);
47 		if (ret == 0) {
48 			ret = port->func->aux(port, true, 8, addr, data, size);
49 			i2c->release(port);
50 		}
51 		return ret;
52 	}
53 	return -ENODEV;
54 }
55 
56 static int
57 aux_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
58 {
59 	struct nvkm_i2c_port *port = adap->algo_data;
60 	struct nvkm_i2c *i2c = nvkm_i2c(port);
61 	struct i2c_msg *msg = msgs;
62 	int ret, mcnt = num;
63 
64 	if (!port->func->aux)
65 		return -ENODEV;
66 
67 	ret = i2c->acquire(port, 0);
68 	if (ret)
69 		return ret;
70 
71 	while (mcnt--) {
72 		u8 remaining = msg->len;
73 		u8 *ptr = msg->buf;
74 
75 		while (remaining) {
76 			u8 cnt = (remaining > 16) ? 16 : remaining;
77 			u8 cmd;
78 
79 			if (msg->flags & I2C_M_RD)
80 				cmd = 1;
81 			else
82 				cmd = 0;
83 
84 			if (mcnt || remaining > 16)
85 				cmd |= 4; /* MOT */
86 
87 			ret = port->func->aux(port, true, cmd, msg->addr, ptr, cnt);
88 			if (ret < 0) {
89 				i2c->release(port);
90 				return ret;
91 			}
92 
93 			ptr += cnt;
94 			remaining -= cnt;
95 		}
96 
97 		msg++;
98 	}
99 
100 	i2c->release(port);
101 	return num;
102 }
103 
104 static u32
105 aux_func(struct i2c_adapter *adap)
106 {
107 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
108 }
109 
110 const struct i2c_algorithm nvkm_i2c_aux_algo = {
111 	.master_xfer = aux_xfer,
112 	.functionality = aux_func
113 };
114