1*83d290c5STom Rini // SPDX-License-Identifier: GPL-2.0+
2f3424c55SHung-ying Tyan /*
3f3424c55SHung-ying Tyan * Chromium OS cros_ec driver - SPI interface
4f3424c55SHung-ying Tyan *
5f3424c55SHung-ying Tyan * Copyright (c) 2012 The Chromium OS Authors.
6f3424c55SHung-ying Tyan */
7f3424c55SHung-ying Tyan
8f3424c55SHung-ying Tyan /*
9f3424c55SHung-ying Tyan * The Matrix Keyboard Protocol driver handles talking to the keyboard
10f3424c55SHung-ying Tyan * controller chip. Mostly this is for keyboard functions, but some other
11f3424c55SHung-ying Tyan * things have slipped in, so we provide generic services to talk to the
12f3424c55SHung-ying Tyan * KBC.
13f3424c55SHung-ying Tyan */
14f3424c55SHung-ying Tyan
15f3424c55SHung-ying Tyan #include <common.h>
16f3424c55SHung-ying Tyan #include <cros_ec.h>
17ea0ebc86SSimon Glass #include <dm.h>
18ea0ebc86SSimon Glass #include <errno.h>
19f3424c55SHung-ying Tyan #include <spi.h>
20f3424c55SHung-ying Tyan
cros_ec_spi_packet(struct udevice * udev,int out_bytes,int in_bytes)21ea0ebc86SSimon Glass int cros_ec_spi_packet(struct udevice *udev, int out_bytes, int in_bytes)
22ea0ebc86SSimon Glass {
23e564f054SSimon Glass struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
24bcbe3d15SSimon Glass struct spi_slave *slave = dev_get_parent_priv(dev->dev);
25527265d8SSimon Glass ulong start;
26527265d8SSimon Glass uint8_t byte;
27a6070283SRandall Spangler int rv;
28a6070283SRandall Spangler
29a6070283SRandall Spangler /* Do the transfer */
30ea0ebc86SSimon Glass if (spi_claim_bus(slave)) {
31a6070283SRandall Spangler debug("%s: Cannot claim SPI bus\n", __func__);
32a6070283SRandall Spangler return -1;
33a6070283SRandall Spangler }
34a6070283SRandall Spangler
35527265d8SSimon Glass rv = spi_xfer(slave, out_bytes * 8, dev->dout, NULL, SPI_XFER_BEGIN);
36527265d8SSimon Glass if (rv)
37527265d8SSimon Glass goto done;
38527265d8SSimon Glass start = get_timer(0);
39527265d8SSimon Glass while (1) {
40527265d8SSimon Glass rv = spi_xfer(slave, 8, NULL, &byte, 0);
41527265d8SSimon Glass if (byte == SPI_PREAMBLE_END_BYTE)
42527265d8SSimon Glass break;
43527265d8SSimon Glass if (rv)
44527265d8SSimon Glass goto done;
45527265d8SSimon Glass if (get_timer(start) > 100) {
46527265d8SSimon Glass rv = -ETIMEDOUT;
47527265d8SSimon Glass goto done;
48527265d8SSimon Glass }
49527265d8SSimon Glass }
50a6070283SRandall Spangler
51527265d8SSimon Glass rv = spi_xfer(slave, in_bytes * 8, NULL, dev->din, 0);
52527265d8SSimon Glass done:
53527265d8SSimon Glass spi_xfer(slave, 0, NULL, NULL, SPI_XFER_END);
54ea0ebc86SSimon Glass spi_release_bus(slave);
55a6070283SRandall Spangler
56a6070283SRandall Spangler if (rv) {
57a6070283SRandall Spangler debug("%s: Cannot complete SPI transfer\n", __func__);
58a6070283SRandall Spangler return -1;
59a6070283SRandall Spangler }
60a6070283SRandall Spangler
61a6070283SRandall Spangler return in_bytes;
62a6070283SRandall Spangler }
63a6070283SRandall Spangler
64f3424c55SHung-ying Tyan /**
65f3424c55SHung-ying Tyan * Send a command to a LPC CROS_EC device and return the reply.
66f3424c55SHung-ying Tyan *
67f3424c55SHung-ying Tyan * The device's internal input/output buffers are used.
68f3424c55SHung-ying Tyan *
69f3424c55SHung-ying Tyan * @param dev CROS_EC device
70f3424c55SHung-ying Tyan * @param cmd Command to send (EC_CMD_...)
71f3424c55SHung-ying Tyan * @param cmd_version Version of command to send (EC_VER_...)
72f3424c55SHung-ying Tyan * @param dout Output data (may be NULL If dout_len=0)
73f3424c55SHung-ying Tyan * @param dout_len Size of output data in bytes
74f3424c55SHung-ying Tyan * @param dinp Returns pointer to response data. This will be
75f3424c55SHung-ying Tyan * untouched unless we return a value > 0.
76f3424c55SHung-ying Tyan * @param din_len Maximum size of response in bytes
77f3424c55SHung-ying Tyan * @return number of bytes in response, or -1 on error
78f3424c55SHung-ying Tyan */
cros_ec_spi_command(struct udevice * udev,uint8_t cmd,int cmd_version,const uint8_t * dout,int dout_len,uint8_t ** dinp,int din_len)79ea0ebc86SSimon Glass int cros_ec_spi_command(struct udevice *udev, uint8_t cmd, int cmd_version,
80ea0ebc86SSimon Glass const uint8_t *dout, int dout_len,
81ea0ebc86SSimon Glass uint8_t **dinp, int din_len)
82ea0ebc86SSimon Glass {
83e564f054SSimon Glass struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
84bcbe3d15SSimon Glass struct spi_slave *slave = dev_get_parent_priv(dev->dev);
85f3424c55SHung-ying Tyan int in_bytes = din_len + 4; /* status, length, checksum, trailer */
86f3424c55SHung-ying Tyan uint8_t *out;
87f3424c55SHung-ying Tyan uint8_t *p;
88f3424c55SHung-ying Tyan int csum, len;
89f3424c55SHung-ying Tyan int rv;
90f3424c55SHung-ying Tyan
91e8c12662SRandall Spangler if (dev->protocol_version != 2) {
92e8c12662SRandall Spangler debug("%s: Unsupported EC protcol version %d\n",
93e8c12662SRandall Spangler __func__, dev->protocol_version);
94e8c12662SRandall Spangler return -1;
95e8c12662SRandall Spangler }
96e8c12662SRandall Spangler
97f3424c55SHung-ying Tyan /*
98f3424c55SHung-ying Tyan * Sanity-check input size to make sure it plus transaction overhead
99f3424c55SHung-ying Tyan * fits in the internal device buffer.
100f3424c55SHung-ying Tyan */
101f3424c55SHung-ying Tyan if (in_bytes > sizeof(dev->din)) {
102f3424c55SHung-ying Tyan debug("%s: Cannot receive %d bytes\n", __func__, din_len);
103f3424c55SHung-ying Tyan return -1;
104f3424c55SHung-ying Tyan }
105f3424c55SHung-ying Tyan
106f3424c55SHung-ying Tyan /* We represent message length as a byte */
107f3424c55SHung-ying Tyan if (dout_len > 0xff) {
108f3424c55SHung-ying Tyan debug("%s: Cannot send %d bytes\n", __func__, dout_len);
109f3424c55SHung-ying Tyan return -1;
110f3424c55SHung-ying Tyan }
111f3424c55SHung-ying Tyan
112f3424c55SHung-ying Tyan /*
113f3424c55SHung-ying Tyan * Clear input buffer so we don't get false hits for MSG_HEADER
114f3424c55SHung-ying Tyan */
115f3424c55SHung-ying Tyan memset(dev->din, '\0', in_bytes);
116f3424c55SHung-ying Tyan
117ea0ebc86SSimon Glass if (spi_claim_bus(slave)) {
118f3424c55SHung-ying Tyan debug("%s: Cannot claim SPI bus\n", __func__);
119f3424c55SHung-ying Tyan return -1;
120f3424c55SHung-ying Tyan }
121f3424c55SHung-ying Tyan
122f3424c55SHung-ying Tyan out = dev->dout;
1232001b9a6SSimon Glass out[0] = EC_CMD_VERSION0 + cmd_version;
124f3424c55SHung-ying Tyan out[1] = cmd;
125f3424c55SHung-ying Tyan out[2] = (uint8_t)dout_len;
126f3424c55SHung-ying Tyan memcpy(out + 3, dout, dout_len);
127f3424c55SHung-ying Tyan csum = cros_ec_calc_checksum(out, 3)
128f3424c55SHung-ying Tyan + cros_ec_calc_checksum(dout, dout_len);
129f3424c55SHung-ying Tyan out[3 + dout_len] = (uint8_t)csum;
130f3424c55SHung-ying Tyan
131f3424c55SHung-ying Tyan /*
132f3424c55SHung-ying Tyan * Send output data and receive input data starting such that the
133f3424c55SHung-ying Tyan * message body will be dword aligned.
134f3424c55SHung-ying Tyan */
135f3424c55SHung-ying Tyan p = dev->din + sizeof(int64_t) - 2;
136f3424c55SHung-ying Tyan len = dout_len + 4;
137f3424c55SHung-ying Tyan cros_ec_dump_data("out", cmd, out, len);
138ea0ebc86SSimon Glass rv = spi_xfer(slave, max(len, in_bytes) * 8, out, p,
139f3424c55SHung-ying Tyan SPI_XFER_BEGIN | SPI_XFER_END);
140f3424c55SHung-ying Tyan
141ea0ebc86SSimon Glass spi_release_bus(slave);
142f3424c55SHung-ying Tyan
143f3424c55SHung-ying Tyan if (rv) {
144f3424c55SHung-ying Tyan debug("%s: Cannot complete SPI transfer\n", __func__);
145f3424c55SHung-ying Tyan return -1;
146f3424c55SHung-ying Tyan }
147f3424c55SHung-ying Tyan
148b4141195SMasahiro Yamada len = min((int)p[1], din_len);
149f3424c55SHung-ying Tyan cros_ec_dump_data("in", -1, p, len + 3);
150f3424c55SHung-ying Tyan
151f3424c55SHung-ying Tyan /* Response code is first byte of message */
152f3424c55SHung-ying Tyan if (p[0] != EC_RES_SUCCESS) {
153f3424c55SHung-ying Tyan printf("%s: Returned status %d\n", __func__, p[0]);
154f3424c55SHung-ying Tyan return -(int)(p[0]);
155f3424c55SHung-ying Tyan }
156f3424c55SHung-ying Tyan
157f3424c55SHung-ying Tyan /* Check checksum */
158f3424c55SHung-ying Tyan csum = cros_ec_calc_checksum(p, len + 2);
159f3424c55SHung-ying Tyan if (csum != p[len + 2]) {
160f3424c55SHung-ying Tyan debug("%s: Invalid checksum rx %#02x, calced %#02x\n", __func__,
161f3424c55SHung-ying Tyan p[2 + len], csum);
162f3424c55SHung-ying Tyan return -1;
163f3424c55SHung-ying Tyan }
164f3424c55SHung-ying Tyan
165f3424c55SHung-ying Tyan /* Anything else is the response data */
166f3424c55SHung-ying Tyan *dinp = p + 2;
167f3424c55SHung-ying Tyan
168f3424c55SHung-ying Tyan return len;
169f3424c55SHung-ying Tyan }
170f3424c55SHung-ying Tyan
cros_ec_probe(struct udevice * dev)171b2568f0dSSimon Glass static int cros_ec_probe(struct udevice *dev)
172ea0ebc86SSimon Glass {
173ea0ebc86SSimon Glass return cros_ec_register(dev);
174ea0ebc86SSimon Glass }
175ea0ebc86SSimon Glass
176b2568f0dSSimon Glass static struct dm_cros_ec_ops cros_ec_ops = {
177ea0ebc86SSimon Glass .packet = cros_ec_spi_packet,
178ea0ebc86SSimon Glass .command = cros_ec_spi_command,
179ea0ebc86SSimon Glass };
180ea0ebc86SSimon Glass
181ea0ebc86SSimon Glass static const struct udevice_id cros_ec_ids[] = {
1823fbb7871SSimon Glass { .compatible = "google,cros-ec-spi" },
183ea0ebc86SSimon Glass { }
184ea0ebc86SSimon Glass };
185ea0ebc86SSimon Glass
186ea0ebc86SSimon Glass U_BOOT_DRIVER(cros_ec_spi) = {
1873fbb7871SSimon Glass .name = "cros_ec_spi",
188ea0ebc86SSimon Glass .id = UCLASS_CROS_EC,
189ea0ebc86SSimon Glass .of_match = cros_ec_ids,
190ea0ebc86SSimon Glass .probe = cros_ec_probe,
191ea0ebc86SSimon Glass .ops = &cros_ec_ops,
192ea0ebc86SSimon Glass };
193