2 * Chromium OS cros_ec driver - SPI interface
4 * Copyright (c) 2012 The Chromium OS Authors.
6 * SPDX-License-Identifier: GPL-2.0+
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
22 DECLARE_GLOBAL_DATA_PTR
;
24 int cros_ec_spi_packet(struct udevice
*udev
, int out_bytes
, int in_bytes
)
26 struct cros_ec_dev
*dev
= dev_get_uclass_priv(udev
);
27 struct spi_slave
*slave
= dev_get_parent_priv(dev
->dev
);
33 if (spi_claim_bus(slave
)) {
34 debug("%s: Cannot claim SPI bus\n", __func__
);
38 rv
= spi_xfer(slave
, out_bytes
* 8, dev
->dout
, NULL
, SPI_XFER_BEGIN
);
43 rv
= spi_xfer(slave
, 8, NULL
, &byte
, 0);
44 if (byte
== SPI_PREAMBLE_END_BYTE
)
48 if (get_timer(start
) > 100) {
54 rv
= spi_xfer(slave
, in_bytes
* 8, NULL
, dev
->din
, 0);
56 spi_xfer(slave
, 0, NULL
, NULL
, SPI_XFER_END
);
57 spi_release_bus(slave
);
60 debug("%s: Cannot complete SPI transfer\n", __func__
);
68 * Send a command to a LPC CROS_EC device and return the reply.
70 * The device's internal input/output buffers are used.
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
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
)
86 struct cros_ec_dev
*dev
= dev_get_uclass_priv(udev
);
87 struct spi_slave
*slave
= dev_get_parent_priv(dev
->dev
);
88 int in_bytes
= din_len
+ 4; /* status, length, checksum, trailer */
94 if (dev
->protocol_version
!= 2) {
95 debug("%s: Unsupported EC protcol version %d\n",
96 __func__
, dev
->protocol_version
);
101 * Sanity-check input size to make sure it plus transaction overhead
102 * fits in the internal device buffer.
104 if (in_bytes
> sizeof(dev
->din
)) {
105 debug("%s: Cannot receive %d bytes\n", __func__
, din_len
);
109 /* We represent message length as a byte */
110 if (dout_len
> 0xff) {
111 debug("%s: Cannot send %d bytes\n", __func__
, dout_len
);
116 * Clear input buffer so we don't get false hits for MSG_HEADER
118 memset(dev
->din
, '\0', in_bytes
);
120 if (spi_claim_bus(slave
)) {
121 debug("%s: Cannot claim SPI bus\n", __func__
);
126 out
[0] = EC_CMD_VERSION0
+ cmd_version
;
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
;
135 * Send output data and receive input data starting such that the
136 * message body will be dword aligned.
138 p
= dev
->din
+ sizeof(int64_t) - 2;
140 cros_ec_dump_data("out", cmd
, out
, len
);
141 rv
= spi_xfer(slave
, max(len
, in_bytes
) * 8, out
, p
,
142 SPI_XFER_BEGIN
| SPI_XFER_END
);
144 spi_release_bus(slave
);
147 debug("%s: Cannot complete SPI transfer\n", __func__
);
151 len
= min((int)p
[1], din_len
);
152 cros_ec_dump_data("in", -1, p
, len
+ 3);
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]);
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__
,
168 /* Anything else is the response data */
174 static int cros_ec_probe(struct udevice
*dev
)
176 return cros_ec_register(dev
);
179 static struct dm_cros_ec_ops cros_ec_ops
= {
180 .packet
= cros_ec_spi_packet
,
181 .command
= cros_ec_spi_command
,
184 static const struct udevice_id cros_ec_ids
[] = {
185 { .compatible
= "google,cros-ec-spi" },
189 U_BOOT_DRIVER(cros_ec_spi
) = {
190 .name
= "cros_ec_spi",
191 .id
= UCLASS_CROS_EC
,
192 .of_match
= cros_ec_ids
,
193 .probe
= cros_ec_probe
,