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Tom Rini83d290c2018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
Hung-ying Tyanf3424c52013-05-15 18:27:30 +08002/*
3 * Chromium OS cros_ec driver - SPI interface
4 *
5 * Copyright (c) 2012 The Chromium OS Authors.
Hung-ying Tyanf3424c52013-05-15 18:27:30 +08006 */
7
8/*
9 * The Matrix Keyboard Protocol driver handles talking to the keyboard
10 * controller chip. Mostly this is for keyboard functions, but some other
11 * things have slipped in, so we provide generic services to talk to the
12 * KBC.
13 */
14
15#include <common.h>
16#include <cros_ec.h>
Simon Glassea0ebc82014-10-13 23:42:16 -060017#include <dm.h>
18#include <errno.h>
Simon Glassf7ae49f2020-05-10 11:40:05 -060019#include <log.h>
Hung-ying Tyanf3424c52013-05-15 18:27:30 +080020#include <spi.h>
21
Simon Glassea0ebc82014-10-13 23:42:16 -060022int cros_ec_spi_packet(struct udevice *udev, int out_bytes, int in_bytes)
23{
Simon Glasse564f052015-03-05 12:25:20 -070024 struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
Simon Glassbcbe3d12015-09-28 23:32:01 -060025 struct spi_slave *slave = dev_get_parent_priv(dev->dev);
Simon Glass527265d2015-02-17 15:29:37 -070026 ulong start;
27 uint8_t byte;
Randall Spanglera6070282014-02-27 13:26:10 -070028 int rv;
29
30 /* Do the transfer */
Simon Glassea0ebc82014-10-13 23:42:16 -060031 if (spi_claim_bus(slave)) {
Randall Spanglera6070282014-02-27 13:26:10 -070032 debug("%s: Cannot claim SPI bus\n", __func__);
33 return -1;
34 }
35
Simon Glass527265d2015-02-17 15:29:37 -070036 rv = spi_xfer(slave, out_bytes * 8, dev->dout, NULL, SPI_XFER_BEGIN);
37 if (rv)
38 goto done;
39 start = get_timer(0);
40 while (1) {
41 rv = spi_xfer(slave, 8, NULL, &byte, 0);
42 if (byte == SPI_PREAMBLE_END_BYTE)
43 break;
44 if (rv)
45 goto done;
46 if (get_timer(start) > 100) {
47 rv = -ETIMEDOUT;
48 goto done;
49 }
50 }
Randall Spanglera6070282014-02-27 13:26:10 -070051
Simon Glass527265d2015-02-17 15:29:37 -070052 rv = spi_xfer(slave, in_bytes * 8, NULL, dev->din, 0);
53done:
54 spi_xfer(slave, 0, NULL, NULL, SPI_XFER_END);
Simon Glassea0ebc82014-10-13 23:42:16 -060055 spi_release_bus(slave);
Randall Spanglera6070282014-02-27 13:26:10 -070056
57 if (rv) {
58 debug("%s: Cannot complete SPI transfer\n", __func__);
59 return -1;
60 }
61
62 return in_bytes;
63}
64
Hung-ying Tyanf3424c52013-05-15 18:27:30 +080065/**
66 * Send a command to a LPC CROS_EC device and return the reply.
67 *
68 * The device's internal input/output buffers are used.
69 *
70 * @param dev CROS_EC device
71 * @param cmd Command to send (EC_CMD_...)
72 * @param cmd_version Version of command to send (EC_VER_...)
73 * @param dout Output data (may be NULL If dout_len=0)
74 * @param dout_len Size of output data in bytes
75 * @param dinp Returns pointer to response data. This will be
76 * untouched unless we return a value > 0.
77 * @param din_len Maximum size of response in bytes
78 * @return number of bytes in response, or -1 on error
79 */
Simon Glassea0ebc82014-10-13 23:42:16 -060080int cros_ec_spi_command(struct udevice *udev, uint8_t cmd, int cmd_version,
81 const uint8_t *dout, int dout_len,
82 uint8_t **dinp, int din_len)
83{
Simon Glasse564f052015-03-05 12:25:20 -070084 struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
Simon Glassbcbe3d12015-09-28 23:32:01 -060085 struct spi_slave *slave = dev_get_parent_priv(dev->dev);
Hung-ying Tyanf3424c52013-05-15 18:27:30 +080086 int in_bytes = din_len + 4; /* status, length, checksum, trailer */
87 uint8_t *out;
88 uint8_t *p;
89 int csum, len;
90 int rv;
91
Randall Spanglere8c12662014-02-27 13:26:08 -070092 if (dev->protocol_version != 2) {
93 debug("%s: Unsupported EC protcol version %d\n",
94 __func__, dev->protocol_version);
95 return -1;
96 }
97
Hung-ying Tyanf3424c52013-05-15 18:27:30 +080098 /*
99 * Sanity-check input size to make sure it plus transaction overhead
100 * fits in the internal device buffer.
101 */
102 if (in_bytes > sizeof(dev->din)) {
103 debug("%s: Cannot receive %d bytes\n", __func__, din_len);
104 return -1;
105 }
106
107 /* We represent message length as a byte */
108 if (dout_len > 0xff) {
109 debug("%s: Cannot send %d bytes\n", __func__, dout_len);
110 return -1;
111 }
112
113 /*
114 * Clear input buffer so we don't get false hits for MSG_HEADER
115 */
116 memset(dev->din, '\0', in_bytes);
117
Simon Glassea0ebc82014-10-13 23:42:16 -0600118 if (spi_claim_bus(slave)) {
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800119 debug("%s: Cannot claim SPI bus\n", __func__);
120 return -1;
121 }
122
123 out = dev->dout;
Simon Glass2001b9a2014-07-07 10:16:37 -0600124 out[0] = EC_CMD_VERSION0 + cmd_version;
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800125 out[1] = cmd;
126 out[2] = (uint8_t)dout_len;
127 memcpy(out + 3, dout, dout_len);
128 csum = cros_ec_calc_checksum(out, 3)
129 + cros_ec_calc_checksum(dout, dout_len);
130 out[3 + dout_len] = (uint8_t)csum;
131
132 /*
133 * Send output data and receive input data starting such that the
134 * message body will be dword aligned.
135 */
136 p = dev->din + sizeof(int64_t) - 2;
137 len = dout_len + 4;
138 cros_ec_dump_data("out", cmd, out, len);
Simon Glassea0ebc82014-10-13 23:42:16 -0600139 rv = spi_xfer(slave, max(len, in_bytes) * 8, out, p,
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800140 SPI_XFER_BEGIN | SPI_XFER_END);
141
Simon Glassea0ebc82014-10-13 23:42:16 -0600142 spi_release_bus(slave);
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800143
144 if (rv) {
145 debug("%s: Cannot complete SPI transfer\n", __func__);
146 return -1;
147 }
148
Masahiro Yamadab4141192014-11-07 03:03:31 +0900149 len = min((int)p[1], din_len);
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800150 cros_ec_dump_data("in", -1, p, len + 3);
151
152 /* Response code is first byte of message */
153 if (p[0] != EC_RES_SUCCESS) {
154 printf("%s: Returned status %d\n", __func__, p[0]);
155 return -(int)(p[0]);
156 }
157
158 /* Check checksum */
159 csum = cros_ec_calc_checksum(p, len + 2);
160 if (csum != p[len + 2]) {
161 debug("%s: Invalid checksum rx %#02x, calced %#02x\n", __func__,
162 p[2 + len], csum);
163 return -1;
164 }
165
166 /* Anything else is the response data */
167 *dinp = p + 2;
168
169 return len;
170}
171
Simon Glassb2568f02015-01-25 08:27:19 -0700172static int cros_ec_probe(struct udevice *dev)
Simon Glassea0ebc82014-10-13 23:42:16 -0600173{
Simon Glassea0ebc82014-10-13 23:42:16 -0600174 return cros_ec_register(dev);
175}
176
Simon Glassb2568f02015-01-25 08:27:19 -0700177static struct dm_cros_ec_ops cros_ec_ops = {
Simon Glassea0ebc82014-10-13 23:42:16 -0600178 .packet = cros_ec_spi_packet,
179 .command = cros_ec_spi_command,
180};
181
182static const struct udevice_id cros_ec_ids[] = {
Simon Glass3fbb7872015-03-26 09:29:39 -0600183 { .compatible = "google,cros-ec-spi" },
Simon Glassea0ebc82014-10-13 23:42:16 -0600184 { }
185};
186
Simon Glassed0f8682020-10-05 05:27:00 -0600187U_BOOT_DRIVER(google_cros_ec_spi) = {
188 .name = "google_cros_ec_spi",
Simon Glassea0ebc82014-10-13 23:42:16 -0600189 .id = UCLASS_CROS_EC,
190 .of_match = cros_ec_ids,
191 .probe = cros_ec_probe,
192 .ops = &cros_ec_ops,
193};