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f3424c55 HT |
1 | /* |
2 | * Chromium OS cros_ec driver - SPI interface | |
3 | * | |
4 | * Copyright (c) 2012 The Chromium OS Authors. | |
f3424c55 | 5 | * |
1a459660 | 6 | * SPDX-License-Identifier: GPL-2.0+ |
f3424c55 HT |
7 | */ |
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 <cros_ec.h> | |
ea0ebc86 SG |
18 | #include <dm.h> |
19 | #include <errno.h> | |
f3424c55 HT |
20 | #include <spi.h> |
21 | ||
ea0ebc86 SG |
22 | DECLARE_GLOBAL_DATA_PTR; |
23 | ||
ea0ebc86 SG |
24 | int cros_ec_spi_packet(struct udevice *udev, int out_bytes, int in_bytes) |
25 | { | |
e564f054 | 26 | struct cros_ec_dev *dev = dev_get_uclass_priv(udev); |
bcbe3d15 | 27 | struct spi_slave *slave = dev_get_parent_priv(dev->dev); |
527265d8 SG |
28 | ulong start; |
29 | uint8_t byte; | |
a6070283 RS |
30 | int rv; |
31 | ||
32 | /* Do the transfer */ | |
ea0ebc86 | 33 | if (spi_claim_bus(slave)) { |
a6070283 RS |
34 | debug("%s: Cannot claim SPI bus\n", __func__); |
35 | return -1; | |
36 | } | |
37 | ||
527265d8 SG |
38 | rv = spi_xfer(slave, out_bytes * 8, dev->dout, NULL, SPI_XFER_BEGIN); |
39 | if (rv) | |
40 | goto done; | |
41 | start = get_timer(0); | |
42 | while (1) { | |
43 | rv = spi_xfer(slave, 8, NULL, &byte, 0); | |
44 | if (byte == SPI_PREAMBLE_END_BYTE) | |
45 | break; | |
46 | if (rv) | |
47 | goto done; | |
48 | if (get_timer(start) > 100) { | |
49 | rv = -ETIMEDOUT; | |
50 | goto done; | |
51 | } | |
52 | } | |
a6070283 | 53 | |
527265d8 SG |
54 | rv = spi_xfer(slave, in_bytes * 8, NULL, dev->din, 0); |
55 | done: | |
56 | spi_xfer(slave, 0, NULL, NULL, SPI_XFER_END); | |
ea0ebc86 | 57 | spi_release_bus(slave); |
a6070283 RS |
58 | |
59 | if (rv) { | |
60 | debug("%s: Cannot complete SPI transfer\n", __func__); | |
61 | return -1; | |
62 | } | |
63 | ||
64 | return in_bytes; | |
65 | } | |
66 | ||
f3424c55 HT |
67 | /** |
68 | * Send a command to a LPC CROS_EC device and return the reply. | |
69 | * | |
70 | * The device's internal input/output buffers are used. | |
71 | * | |
72 | * @param dev CROS_EC device | |
73 | * @param cmd Command to send (EC_CMD_...) | |
74 | * @param cmd_version Version of command to send (EC_VER_...) | |
75 | * @param dout Output data (may be NULL If dout_len=0) | |
76 | * @param dout_len Size of output data in bytes | |
77 | * @param dinp Returns pointer to response data. This will be | |
78 | * untouched unless we return a value > 0. | |
79 | * @param din_len Maximum size of response in bytes | |
80 | * @return number of bytes in response, or -1 on error | |
81 | */ | |
ea0ebc86 SG |
82 | int cros_ec_spi_command(struct udevice *udev, uint8_t cmd, int cmd_version, |
83 | const uint8_t *dout, int dout_len, | |
84 | uint8_t **dinp, int din_len) | |
85 | { | |
e564f054 | 86 | struct cros_ec_dev *dev = dev_get_uclass_priv(udev); |
bcbe3d15 | 87 | struct spi_slave *slave = dev_get_parent_priv(dev->dev); |
f3424c55 HT |
88 | int in_bytes = din_len + 4; /* status, length, checksum, trailer */ |
89 | uint8_t *out; | |
90 | uint8_t *p; | |
91 | int csum, len; | |
92 | int rv; | |
93 | ||
e8c12662 RS |
94 | if (dev->protocol_version != 2) { |
95 | debug("%s: Unsupported EC protcol version %d\n", | |
96 | __func__, dev->protocol_version); | |
97 | return -1; | |
98 | } | |
99 | ||
f3424c55 HT |
100 | /* |
101 | * Sanity-check input size to make sure it plus transaction overhead | |
102 | * fits in the internal device buffer. | |
103 | */ | |
104 | if (in_bytes > sizeof(dev->din)) { | |
105 | debug("%s: Cannot receive %d bytes\n", __func__, din_len); | |
106 | return -1; | |
107 | } | |
108 | ||
109 | /* We represent message length as a byte */ | |
110 | if (dout_len > 0xff) { | |
111 | debug("%s: Cannot send %d bytes\n", __func__, dout_len); | |
112 | return -1; | |
113 | } | |
114 | ||
115 | /* | |
116 | * Clear input buffer so we don't get false hits for MSG_HEADER | |
117 | */ | |
118 | memset(dev->din, '\0', in_bytes); | |
119 | ||
ea0ebc86 | 120 | if (spi_claim_bus(slave)) { |
f3424c55 HT |
121 | debug("%s: Cannot claim SPI bus\n", __func__); |
122 | return -1; | |
123 | } | |
124 | ||
125 | out = dev->dout; | |
2001b9a6 | 126 | out[0] = EC_CMD_VERSION0 + cmd_version; |
f3424c55 HT |
127 | out[1] = cmd; |
128 | out[2] = (uint8_t)dout_len; | |
129 | memcpy(out + 3, dout, dout_len); | |
130 | csum = cros_ec_calc_checksum(out, 3) | |
131 | + cros_ec_calc_checksum(dout, dout_len); | |
132 | out[3 + dout_len] = (uint8_t)csum; | |
133 | ||
134 | /* | |
135 | * Send output data and receive input data starting such that the | |
136 | * message body will be dword aligned. | |
137 | */ | |
138 | p = dev->din + sizeof(int64_t) - 2; | |
139 | len = dout_len + 4; | |
140 | cros_ec_dump_data("out", cmd, out, len); | |
ea0ebc86 | 141 | rv = spi_xfer(slave, max(len, in_bytes) * 8, out, p, |
f3424c55 HT |
142 | SPI_XFER_BEGIN | SPI_XFER_END); |
143 | ||
ea0ebc86 | 144 | spi_release_bus(slave); |
f3424c55 HT |
145 | |
146 | if (rv) { | |
147 | debug("%s: Cannot complete SPI transfer\n", __func__); | |
148 | return -1; | |
149 | } | |
150 | ||
b4141195 | 151 | len = min((int)p[1], din_len); |
f3424c55 HT |
152 | cros_ec_dump_data("in", -1, p, len + 3); |
153 | ||
154 | /* Response code is first byte of message */ | |
155 | if (p[0] != EC_RES_SUCCESS) { | |
156 | printf("%s: Returned status %d\n", __func__, p[0]); | |
157 | return -(int)(p[0]); | |
158 | } | |
159 | ||
160 | /* Check checksum */ | |
161 | csum = cros_ec_calc_checksum(p, len + 2); | |
162 | if (csum != p[len + 2]) { | |
163 | debug("%s: Invalid checksum rx %#02x, calced %#02x\n", __func__, | |
164 | p[2 + len], csum); | |
165 | return -1; | |
166 | } | |
167 | ||
168 | /* Anything else is the response data */ | |
169 | *dinp = p + 2; | |
170 | ||
171 | return len; | |
172 | } | |
173 | ||
b2568f0d | 174 | static int cros_ec_probe(struct udevice *dev) |
ea0ebc86 | 175 | { |
ea0ebc86 SG |
176 | return cros_ec_register(dev); |
177 | } | |
178 | ||
b2568f0d | 179 | static struct dm_cros_ec_ops cros_ec_ops = { |
ea0ebc86 SG |
180 | .packet = cros_ec_spi_packet, |
181 | .command = cros_ec_spi_command, | |
182 | }; | |
183 | ||
184 | static const struct udevice_id cros_ec_ids[] = { | |
3fbb7871 | 185 | { .compatible = "google,cros-ec-spi" }, |
ea0ebc86 SG |
186 | { } |
187 | }; | |
188 | ||
189 | U_BOOT_DRIVER(cros_ec_spi) = { | |
3fbb7871 | 190 | .name = "cros_ec_spi", |
ea0ebc86 SG |
191 | .id = UCLASS_CROS_EC, |
192 | .of_match = cros_ec_ids, | |
193 | .probe = cros_ec_probe, | |
194 | .ops = &cros_ec_ops, | |
195 | }; |