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Hung-ying Tyanf3424c52013-05-15 18:27:30 +08001/*
2 * Chromium OS cros_ec driver - SPI interface
3 *
4 * Copyright (c) 2012 The Chromium OS Authors.
Hung-ying Tyanf3424c52013-05-15 18:27:30 +08005 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02006 * SPDX-License-Identifier: GPL-2.0+
Hung-ying Tyanf3424c52013-05-15 18:27:30 +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 <cros_ec.h>
Simon Glassea0ebc82014-10-13 23:42:16 -060018#include <dm.h>
19#include <errno.h>
Hung-ying Tyanf3424c52013-05-15 18:27:30 +080020#include <spi.h>
21
Simon Glassea0ebc82014-10-13 23:42:16 -060022DECLARE_GLOBAL_DATA_PTR;
23
Simon Glassea0ebc82014-10-13 23:42:16 -060024int cros_ec_spi_packet(struct udevice *udev, int out_bytes, int in_bytes)
25{
Simon Glasse564f052015-03-05 12:25:20 -070026 struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
Simon Glassea0ebc82014-10-13 23:42:16 -060027 struct spi_slave *slave = dev_get_parentdata(dev->dev);
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 Glassea0ebc82014-10-13 23:42:16 -060036 rv = spi_xfer(slave, max(out_bytes, in_bytes) * 8,
Randall Spanglera6070282014-02-27 13:26:10 -070037 dev->dout, dev->din,
38 SPI_XFER_BEGIN | SPI_XFER_END);
39
Simon Glassea0ebc82014-10-13 23:42:16 -060040 spi_release_bus(slave);
Randall Spanglera6070282014-02-27 13:26:10 -070041
42 if (rv) {
43 debug("%s: Cannot complete SPI transfer\n", __func__);
44 return -1;
45 }
46
47 return in_bytes;
48}
49
Hung-ying Tyanf3424c52013-05-15 18:27:30 +080050/**
51 * Send a command to a LPC CROS_EC device and return the reply.
52 *
53 * The device's internal input/output buffers are used.
54 *
55 * @param dev CROS_EC device
56 * @param cmd Command to send (EC_CMD_...)
57 * @param cmd_version Version of command to send (EC_VER_...)
58 * @param dout Output data (may be NULL If dout_len=0)
59 * @param dout_len Size of output data in bytes
60 * @param dinp Returns pointer to response data. This will be
61 * untouched unless we return a value > 0.
62 * @param din_len Maximum size of response in bytes
63 * @return number of bytes in response, or -1 on error
64 */
Simon Glassea0ebc82014-10-13 23:42:16 -060065int cros_ec_spi_command(struct udevice *udev, uint8_t cmd, int cmd_version,
66 const uint8_t *dout, int dout_len,
67 uint8_t **dinp, int din_len)
68{
Simon Glasse564f052015-03-05 12:25:20 -070069 struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
Simon Glassea0ebc82014-10-13 23:42:16 -060070 struct spi_slave *slave = dev_get_parentdata(dev->dev);
Hung-ying Tyanf3424c52013-05-15 18:27:30 +080071 int in_bytes = din_len + 4; /* status, length, checksum, trailer */
72 uint8_t *out;
73 uint8_t *p;
74 int csum, len;
75 int rv;
76
Randall Spanglere8c12662014-02-27 13:26:08 -070077 if (dev->protocol_version != 2) {
78 debug("%s: Unsupported EC protcol version %d\n",
79 __func__, dev->protocol_version);
80 return -1;
81 }
82
Hung-ying Tyanf3424c52013-05-15 18:27:30 +080083 /*
84 * Sanity-check input size to make sure it plus transaction overhead
85 * fits in the internal device buffer.
86 */
87 if (in_bytes > sizeof(dev->din)) {
88 debug("%s: Cannot receive %d bytes\n", __func__, din_len);
89 return -1;
90 }
91
92 /* We represent message length as a byte */
93 if (dout_len > 0xff) {
94 debug("%s: Cannot send %d bytes\n", __func__, dout_len);
95 return -1;
96 }
97
98 /*
99 * Clear input buffer so we don't get false hits for MSG_HEADER
100 */
101 memset(dev->din, '\0', in_bytes);
102
Simon Glassea0ebc82014-10-13 23:42:16 -0600103 if (spi_claim_bus(slave)) {
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800104 debug("%s: Cannot claim SPI bus\n", __func__);
105 return -1;
106 }
107
108 out = dev->dout;
Simon Glass2001b9a2014-07-07 10:16:37 -0600109 out[0] = EC_CMD_VERSION0 + cmd_version;
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800110 out[1] = cmd;
111 out[2] = (uint8_t)dout_len;
112 memcpy(out + 3, dout, dout_len);
113 csum = cros_ec_calc_checksum(out, 3)
114 + cros_ec_calc_checksum(dout, dout_len);
115 out[3 + dout_len] = (uint8_t)csum;
116
117 /*
118 * Send output data and receive input data starting such that the
119 * message body will be dword aligned.
120 */
121 p = dev->din + sizeof(int64_t) - 2;
122 len = dout_len + 4;
123 cros_ec_dump_data("out", cmd, out, len);
Simon Glassea0ebc82014-10-13 23:42:16 -0600124 rv = spi_xfer(slave, max(len, in_bytes) * 8, out, p,
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800125 SPI_XFER_BEGIN | SPI_XFER_END);
126
Simon Glassea0ebc82014-10-13 23:42:16 -0600127 spi_release_bus(slave);
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800128
129 if (rv) {
130 debug("%s: Cannot complete SPI transfer\n", __func__);
131 return -1;
132 }
133
Masahiro Yamadab4141192014-11-07 03:03:31 +0900134 len = min((int)p[1], din_len);
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800135 cros_ec_dump_data("in", -1, p, len + 3);
136
137 /* Response code is first byte of message */
138 if (p[0] != EC_RES_SUCCESS) {
139 printf("%s: Returned status %d\n", __func__, p[0]);
140 return -(int)(p[0]);
141 }
142
143 /* Check checksum */
144 csum = cros_ec_calc_checksum(p, len + 2);
145 if (csum != p[len + 2]) {
146 debug("%s: Invalid checksum rx %#02x, calced %#02x\n", __func__,
147 p[2 + len], csum);
148 return -1;
149 }
150
151 /* Anything else is the response data */
152 *dinp = p + 2;
153
154 return len;
155}
156
Simon Glassb2568f02015-01-25 08:27:19 -0700157static int cros_ec_probe(struct udevice *dev)
Simon Glassea0ebc82014-10-13 23:42:16 -0600158{
Simon Glassea0ebc82014-10-13 23:42:16 -0600159 return cros_ec_register(dev);
160}
161
Simon Glassb2568f02015-01-25 08:27:19 -0700162static struct dm_cros_ec_ops cros_ec_ops = {
Simon Glassea0ebc82014-10-13 23:42:16 -0600163 .packet = cros_ec_spi_packet,
164 .command = cros_ec_spi_command,
165};
166
167static const struct udevice_id cros_ec_ids[] = {
Simon Glass3fbb7872015-03-26 09:29:39 -0600168 { .compatible = "google,cros-ec-spi" },
Simon Glassea0ebc82014-10-13 23:42:16 -0600169 { }
170};
171
172U_BOOT_DRIVER(cros_ec_spi) = {
Simon Glass3fbb7872015-03-26 09:29:39 -0600173 .name = "cros_ec_spi",
Simon Glassea0ebc82014-10-13 23:42:16 -0600174 .id = UCLASS_CROS_EC,
175 .of_match = cros_ec_ids,
176 .probe = cros_ec_probe,
177 .ops = &cros_ec_ops,
178};