1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright 2019 Google LLC |
4 | */ |
5 | |
6 | #include <linux/errno.h> |
7 | #include <linux/export.h> |
8 | #include <linux/platform_data/wilco-ec.h> |
9 | #include <linux/string.h> |
10 | #include <linux/types.h> |
11 | #include <asm/unaligned.h> |
12 | |
13 | /* Operation code; what the EC should do with the property */ |
14 | enum ec_property_op { |
15 | EC_OP_GET = 0, |
16 | EC_OP_SET = 1, |
17 | }; |
18 | |
19 | struct ec_property_request { |
20 | u8 op; /* One of enum ec_property_op */ |
21 | u8 property_id[4]; /* The 32 bit PID is stored Little Endian */ |
22 | u8 length; |
23 | u8 data[WILCO_EC_PROPERTY_MAX_SIZE]; |
24 | } __packed; |
25 | |
26 | struct ec_property_response { |
27 | u8 reserved[2]; |
28 | u8 op; /* One of enum ec_property_op */ |
29 | u8 property_id[4]; /* The 32 bit PID is stored Little Endian */ |
30 | u8 length; |
31 | u8 data[WILCO_EC_PROPERTY_MAX_SIZE]; |
32 | } __packed; |
33 | |
34 | static int send_property_msg(struct wilco_ec_device *ec, |
35 | struct ec_property_request *rq, |
36 | struct ec_property_response *rs) |
37 | { |
38 | struct wilco_ec_message ec_msg; |
39 | int ret; |
40 | |
41 | memset(&ec_msg, 0, sizeof(ec_msg)); |
42 | ec_msg.type = WILCO_EC_MSG_PROPERTY; |
43 | ec_msg.request_data = rq; |
44 | ec_msg.request_size = sizeof(*rq); |
45 | ec_msg.response_data = rs; |
46 | ec_msg.response_size = sizeof(*rs); |
47 | |
48 | ret = wilco_ec_mailbox(ec, msg: &ec_msg); |
49 | if (ret < 0) |
50 | return ret; |
51 | if (rs->op != rq->op) |
52 | return -EBADMSG; |
53 | if (memcmp(p: rq->property_id, q: rs->property_id, size: sizeof(rs->property_id))) |
54 | return -EBADMSG; |
55 | |
56 | return 0; |
57 | } |
58 | |
59 | int wilco_ec_get_property(struct wilco_ec_device *ec, |
60 | struct wilco_ec_property_msg *prop_msg) |
61 | { |
62 | struct ec_property_request rq; |
63 | struct ec_property_response rs; |
64 | int ret; |
65 | |
66 | memset(&rq, 0, sizeof(rq)); |
67 | rq.op = EC_OP_GET; |
68 | put_unaligned_le32(val: prop_msg->property_id, p: rq.property_id); |
69 | |
70 | ret = send_property_msg(ec, rq: &rq, rs: &rs); |
71 | if (ret < 0) |
72 | return ret; |
73 | |
74 | prop_msg->length = rs.length; |
75 | memcpy(prop_msg->data, rs.data, rs.length); |
76 | |
77 | return 0; |
78 | } |
79 | EXPORT_SYMBOL_GPL(wilco_ec_get_property); |
80 | |
81 | int wilco_ec_set_property(struct wilco_ec_device *ec, |
82 | struct wilco_ec_property_msg *prop_msg) |
83 | { |
84 | struct ec_property_request rq; |
85 | struct ec_property_response rs; |
86 | int ret; |
87 | |
88 | memset(&rq, 0, sizeof(rq)); |
89 | rq.op = EC_OP_SET; |
90 | put_unaligned_le32(val: prop_msg->property_id, p: rq.property_id); |
91 | rq.length = prop_msg->length; |
92 | memcpy(rq.data, prop_msg->data, prop_msg->length); |
93 | |
94 | ret = send_property_msg(ec, rq: &rq, rs: &rs); |
95 | if (ret < 0) |
96 | return ret; |
97 | if (rs.length != prop_msg->length) |
98 | return -EBADMSG; |
99 | |
100 | return 0; |
101 | } |
102 | EXPORT_SYMBOL_GPL(wilco_ec_set_property); |
103 | |
104 | int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id, |
105 | u8 *val) |
106 | { |
107 | struct wilco_ec_property_msg msg; |
108 | int ret; |
109 | |
110 | msg.property_id = property_id; |
111 | |
112 | ret = wilco_ec_get_property(ec, &msg); |
113 | if (ret < 0) |
114 | return ret; |
115 | if (msg.length != 1) |
116 | return -EBADMSG; |
117 | |
118 | *val = msg.data[0]; |
119 | |
120 | return 0; |
121 | } |
122 | EXPORT_SYMBOL_GPL(wilco_ec_get_byte_property); |
123 | |
124 | int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id, |
125 | u8 val) |
126 | { |
127 | struct wilco_ec_property_msg msg; |
128 | |
129 | msg.property_id = property_id; |
130 | msg.data[0] = val; |
131 | msg.length = 1; |
132 | |
133 | return wilco_ec_set_property(ec, &msg); |
134 | } |
135 | EXPORT_SYMBOL_GPL(wilco_ec_set_byte_property); |
136 | |