blob: 07624a136fa47def2c330ae229c25a1cd822a3dc [file] [log] [blame]
Hung-ying Tyanc8d33282013-05-15 18:27:31 +08001/*
2 * Chromium OS cros_ec driver - LPC interface
3 *
4 * Copyright (c) 2012 The Chromium OS Authors.
Hung-ying Tyanc8d33282013-05-15 18:27:31 +08005 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02006 * SPDX-License-Identifier: GPL-2.0+
Hung-ying Tyanc8d33282013-05-15 18:27:31 +08007 */
8
9/*
10 * The Matrix Keyboard Protocol driver handles talking to the keyboard
11 * controller chip. Mostly this is for keyboard functions, but some other
12 * things have slipped in, so we provide generic services to talk to the
13 * KBC.
14 */
15
16#include <common.h>
17#include <command.h>
18#include <cros_ec.h>
19#include <asm/io.h>
20
21#ifdef DEBUG_TRACE
22#define debug_trace(fmt, b...) debug(fmt, ##b)
23#else
24#define debug_trace(fmt, b...)
25#endif
26
27static int wait_for_sync(struct cros_ec_dev *dev)
28{
29 unsigned long start;
30
31 start = get_timer(0);
32 while (inb(EC_LPC_ADDR_HOST_CMD) & EC_LPC_STATUS_BUSY_MASK) {
33 if (get_timer(start) > 1000) {
34 debug("%s: Timeout waiting for CROS_EC sync\n",
35 __func__);
36 return -1;
37 }
38 }
39
40 return 0;
41}
42
Hung-ying Tyanc8d33282013-05-15 18:27:31 +080043int cros_ec_lpc_command(struct cros_ec_dev *dev, uint8_t cmd, int cmd_version,
44 const uint8_t *dout, int dout_len,
45 uint8_t **dinp, int din_len)
46{
47 const int cmd_addr = EC_LPC_ADDR_HOST_CMD;
48 const int data_addr = EC_LPC_ADDR_HOST_DATA;
49 const int args_addr = EC_LPC_ADDR_HOST_ARGS;
50 const int param_addr = EC_LPC_ADDR_HOST_PARAM;
51
52 struct ec_lpc_host_args args;
53 uint8_t *d;
54 int csum;
55 int i;
56
Simon Glassf1269922014-10-10 07:30:15 -060057 if (dout_len > EC_PROTO2_MAX_PARAM_SIZE) {
Hung-ying Tyanc8d33282013-05-15 18:27:31 +080058 debug("%s: Cannot send %d bytes\n", __func__, dout_len);
59 return -1;
60 }
61
62 /* Fill in args */
63 args.flags = EC_HOST_ARGS_FLAG_FROM_HOST;
64 args.command_version = cmd_version;
65 args.data_size = dout_len;
66
67 /* Calculate checksum */
68 csum = cmd + args.flags + args.command_version + args.data_size;
69 for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++)
70 csum += *d;
71
72 args.checksum = (uint8_t)csum;
73
74 if (wait_for_sync(dev)) {
75 debug("%s: Timeout waiting ready\n", __func__);
76 return -1;
77 }
78
79 /* Write args */
80 for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++)
81 outb(*d, args_addr + i);
82
83 /* Write data, if any */
84 debug_trace("cmd: %02x, ver: %02x", cmd, cmd_version);
85 for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++) {
86 outb(*d, param_addr + i);
87 debug_trace("%02x ", *d);
88 }
89
90 outb(cmd, cmd_addr);
91 debug_trace("\n");
92
93 if (wait_for_sync(dev)) {
94 debug("%s: Timeout waiting for response\n", __func__);
95 return -1;
96 }
97
98 /* Check result */
99 i = inb(data_addr);
100 if (i) {
101 debug("%s: CROS_EC result code %d\n", __func__, i);
102 return -i;
103 }
104
105 /* Read back args */
106 for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++)
107 *d = inb(args_addr + i);
108
109 /*
110 * If EC didn't modify args flags, then somehow we sent a new-style
111 * command to an old EC, which means it would have read its params
112 * from the wrong place.
113 */
114 if (!(args.flags & EC_HOST_ARGS_FLAG_TO_HOST)) {
115 debug("%s: CROS_EC protocol mismatch\n", __func__);
116 return -EC_RES_INVALID_RESPONSE;
117 }
118
119 if (args.data_size > din_len) {
120 debug("%s: CROS_EC returned too much data %d > %d\n",
121 __func__, args.data_size, din_len);
122 return -EC_RES_INVALID_RESPONSE;
123 }
124
125 /* Read data, if any */
126 for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++) {
127 *d = inb(param_addr + i);
128 debug_trace("%02x ", *d);
129 }
130 debug_trace("\n");
131
132 /* Verify checksum */
133 csum = cmd + args.flags + args.command_version + args.data_size;
134 for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++)
135 csum += *d;
136
137 if (args.checksum != (uint8_t)csum) {
138 debug("%s: CROS_EC response has invalid checksum\n", __func__);
139 return -EC_RES_INVALID_CHECKSUM;
140 }
141 *dinp = dev->din;
142
143 /* Return actual amount of data received */
144 return args.data_size;
145}
146
147/**
148 * Initialize LPC protocol.
149 *
150 * @param dev CROS_EC device
151 * @param blob Device tree blob
152 * @return 0 if ok, -1 on error
153 */
154int cros_ec_lpc_init(struct cros_ec_dev *dev, const void *blob)
155{
156 int byte, i;
157
158 /* See if we can find an EC at the other end */
159 byte = 0xff;
160 byte &= inb(EC_LPC_ADDR_HOST_CMD);
161 byte &= inb(EC_LPC_ADDR_HOST_DATA);
Simon Glassf1269922014-10-10 07:30:15 -0600162 for (i = 0; i < EC_PROTO2_MAX_PARAM_SIZE && (byte == 0xff); i++)
Hung-ying Tyanc8d33282013-05-15 18:27:31 +0800163 byte &= inb(EC_LPC_ADDR_HOST_PARAM + i);
164 if (byte == 0xff) {
165 debug("%s: CROS_EC device not found on LPC bus\n",
166 __func__);
167 return -1;
168 }
169
170 return 0;
171}
172
173/*
174 * Test if LPC command args are supported.
175 *
176 * The cheapest way to do this is by looking for the memory-mapped
177 * flag. This is faster than sending a new-style 'hello' command and
178 * seeing whether the EC sets the EC_HOST_ARGS_FLAG_FROM_HOST flag
179 * in args when it responds.
180 */
181int cros_ec_lpc_check_version(struct cros_ec_dev *dev)
182{
183 if (inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID) == 'E' &&
184 inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID + 1)
185 == 'C' &&
186 (inb(EC_LPC_ADDR_MEMMAP +
187 EC_MEMMAP_HOST_CMD_FLAGS) &
188 EC_HOST_CMD_FLAG_LPC_ARGS_SUPPORTED)) {
Vadim Bendebury4ff9b462014-02-27 13:26:04 -0700189 return 0;
Hung-ying Tyanc8d33282013-05-15 18:27:31 +0800190 }
Hung-ying Tyanc8d33282013-05-15 18:27:31 +0800191
Vadim Bendebury4ff9b462014-02-27 13:26:04 -0700192 printf("%s: ERROR: old EC interface not supported\n", __func__);
193 return -1;
Hung-ying Tyanc8d33282013-05-15 18:27:31 +0800194}