blob: 78378410f444de585490bc271428e806ef17205f [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>
Simon Glass72a38e02015-03-26 09:29:30 -060017#include <dm.h>
Hung-ying Tyanc8d33282013-05-15 18:27:31 +080018#include <command.h>
19#include <cros_ec.h>
20#include <asm/io.h>
21
22#ifdef DEBUG_TRACE
23#define debug_trace(fmt, b...) debug(fmt, ##b)
24#else
25#define debug_trace(fmt, b...)
26#endif
27
28static int wait_for_sync(struct cros_ec_dev *dev)
29{
30 unsigned long start;
31
32 start = get_timer(0);
33 while (inb(EC_LPC_ADDR_HOST_CMD) & EC_LPC_STATUS_BUSY_MASK) {
34 if (get_timer(start) > 1000) {
35 debug("%s: Timeout waiting for CROS_EC sync\n",
36 __func__);
37 return -1;
38 }
39 }
40
41 return 0;
42}
43
Simon Glass72a38e02015-03-26 09:29:30 -060044int cros_ec_lpc_command(struct udevice *udev, uint8_t cmd, int cmd_version,
45 const uint8_t *dout, int dout_len,
46 uint8_t **dinp, int din_len)
47{
48 struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
Hung-ying Tyanc8d33282013-05-15 18:27:31 +080049 const int cmd_addr = EC_LPC_ADDR_HOST_CMD;
50 const int data_addr = EC_LPC_ADDR_HOST_DATA;
51 const int args_addr = EC_LPC_ADDR_HOST_ARGS;
52 const int param_addr = EC_LPC_ADDR_HOST_PARAM;
53
54 struct ec_lpc_host_args args;
55 uint8_t *d;
56 int csum;
57 int i;
58
Simon Glassf1269922014-10-10 07:30:15 -060059 if (dout_len > EC_PROTO2_MAX_PARAM_SIZE) {
Hung-ying Tyanc8d33282013-05-15 18:27:31 +080060 debug("%s: Cannot send %d bytes\n", __func__, dout_len);
61 return -1;
62 }
63
64 /* Fill in args */
65 args.flags = EC_HOST_ARGS_FLAG_FROM_HOST;
66 args.command_version = cmd_version;
67 args.data_size = dout_len;
68
69 /* Calculate checksum */
70 csum = cmd + args.flags + args.command_version + args.data_size;
71 for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++)
72 csum += *d;
73
74 args.checksum = (uint8_t)csum;
75
76 if (wait_for_sync(dev)) {
77 debug("%s: Timeout waiting ready\n", __func__);
78 return -1;
79 }
80
81 /* Write args */
82 for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++)
83 outb(*d, args_addr + i);
84
85 /* Write data, if any */
86 debug_trace("cmd: %02x, ver: %02x", cmd, cmd_version);
87 for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++) {
88 outb(*d, param_addr + i);
89 debug_trace("%02x ", *d);
90 }
91
92 outb(cmd, cmd_addr);
93 debug_trace("\n");
94
95 if (wait_for_sync(dev)) {
96 debug("%s: Timeout waiting for response\n", __func__);
97 return -1;
98 }
99
100 /* Check result */
101 i = inb(data_addr);
102 if (i) {
103 debug("%s: CROS_EC result code %d\n", __func__, i);
104 return -i;
105 }
106
107 /* Read back args */
108 for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++)
109 *d = inb(args_addr + i);
110
111 /*
112 * If EC didn't modify args flags, then somehow we sent a new-style
113 * command to an old EC, which means it would have read its params
114 * from the wrong place.
115 */
116 if (!(args.flags & EC_HOST_ARGS_FLAG_TO_HOST)) {
117 debug("%s: CROS_EC protocol mismatch\n", __func__);
118 return -EC_RES_INVALID_RESPONSE;
119 }
120
121 if (args.data_size > din_len) {
122 debug("%s: CROS_EC returned too much data %d > %d\n",
123 __func__, args.data_size, din_len);
124 return -EC_RES_INVALID_RESPONSE;
125 }
126
127 /* Read data, if any */
128 for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++) {
129 *d = inb(param_addr + i);
130 debug_trace("%02x ", *d);
131 }
132 debug_trace("\n");
133
134 /* Verify checksum */
135 csum = cmd + args.flags + args.command_version + args.data_size;
136 for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++)
137 csum += *d;
138
139 if (args.checksum != (uint8_t)csum) {
140 debug("%s: CROS_EC response has invalid checksum\n", __func__);
141 return -EC_RES_INVALID_CHECKSUM;
142 }
143 *dinp = dev->din;
144
145 /* Return actual amount of data received */
146 return args.data_size;
147}
148
149/**
150 * Initialize LPC protocol.
151 *
152 * @param dev CROS_EC device
153 * @param blob Device tree blob
154 * @return 0 if ok, -1 on error
155 */
156int cros_ec_lpc_init(struct cros_ec_dev *dev, const void *blob)
157{
158 int byte, i;
159
160 /* See if we can find an EC at the other end */
161 byte = 0xff;
162 byte &= inb(EC_LPC_ADDR_HOST_CMD);
163 byte &= inb(EC_LPC_ADDR_HOST_DATA);
Simon Glassf1269922014-10-10 07:30:15 -0600164 for (i = 0; i < EC_PROTO2_MAX_PARAM_SIZE && (byte == 0xff); i++)
Hung-ying Tyanc8d33282013-05-15 18:27:31 +0800165 byte &= inb(EC_LPC_ADDR_HOST_PARAM + i);
166 if (byte == 0xff) {
167 debug("%s: CROS_EC device not found on LPC bus\n",
168 __func__);
169 return -1;
170 }
171
172 return 0;
173}
174
175/*
176 * Test if LPC command args are supported.
177 *
178 * The cheapest way to do this is by looking for the memory-mapped
179 * flag. This is faster than sending a new-style 'hello' command and
180 * seeing whether the EC sets the EC_HOST_ARGS_FLAG_FROM_HOST flag
181 * in args when it responds.
182 */
Simon Glass72a38e02015-03-26 09:29:30 -0600183static int cros_ec_lpc_check_version(struct udevice *dev)
Hung-ying Tyanc8d33282013-05-15 18:27:31 +0800184{
185 if (inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID) == 'E' &&
186 inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID + 1)
187 == 'C' &&
188 (inb(EC_LPC_ADDR_MEMMAP +
189 EC_MEMMAP_HOST_CMD_FLAGS) &
190 EC_HOST_CMD_FLAG_LPC_ARGS_SUPPORTED)) {
Vadim Bendebury4ff9b462014-02-27 13:26:04 -0700191 return 0;
Hung-ying Tyanc8d33282013-05-15 18:27:31 +0800192 }
Hung-ying Tyanc8d33282013-05-15 18:27:31 +0800193
Vadim Bendebury4ff9b462014-02-27 13:26:04 -0700194 printf("%s: ERROR: old EC interface not supported\n", __func__);
195 return -1;
Hung-ying Tyanc8d33282013-05-15 18:27:31 +0800196}
Simon Glass72a38e02015-03-26 09:29:30 -0600197
Simon Glass72a38e02015-03-26 09:29:30 -0600198static int cros_ec_probe(struct udevice *dev)
199{
200 return cros_ec_register(dev);
201}
202
203static struct dm_cros_ec_ops cros_ec_ops = {
204 .command = cros_ec_lpc_command,
205 .check_version = cros_ec_lpc_check_version,
206};
207
208static const struct udevice_id cros_ec_ids[] = {
Simon Glass3fbb7872015-03-26 09:29:39 -0600209 { .compatible = "google,cros-ec-lpc" },
Simon Glass72a38e02015-03-26 09:29:30 -0600210 { }
211};
212
213U_BOOT_DRIVER(cros_ec_lpc) = {
Simon Glass3fbb7872015-03-26 09:29:39 -0600214 .name = "cros_ec_lpc",
Simon Glass72a38e02015-03-26 09:29:30 -0600215 .id = UCLASS_CROS_EC,
216 .of_match = cros_ec_ids,
217 .probe = cros_ec_probe,
218 .ops = &cros_ec_ops,
219};