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/* SPDX-License-Identifier: GPL-2.0-only */
#include <arch/io.h>
#include <console/console.h>
#include "mec5055.h"
static const u16 EC_CTRL = 0x910;
static const u16 EC_DATA = 0x911;
static void wait_ec(void)
{
u8 v;
do {
outb(0, EC_CTRL);
v = inb(EC_DATA);
} while (v != 0);
}
static enum cb_err read_ec_regs(u8 start, u8 *sdata, u8 count)
{
if (start >= 0x20 || start + count > 0x20) {
printk(BIOS_ERR, "%s: Invalid start or count argument.\n", __func__);
return CB_ERR_ARG;
}
while (count--) {
outb(start + 0x10, EC_CTRL);
*sdata = inb(EC_DATA);
sdata++;
start++;
}
return CB_SUCCESS;
}
static enum cb_err write_ec_regs(u8 start, const u8 *sdata, u8 count)
{
if (start >= 0x20 || start + count > 0x20) {
printk(BIOS_ERR, "%s: Invalid start or count argument.\n", __func__);
return CB_ERR_ARG;
}
while (count--) {
outb(start + 0x10, EC_CTRL);
outb(*sdata, EC_DATA);
sdata++;
start++;
}
return CB_SUCCESS;
}
/*
* Steps to communicate with the EC:
* 1. send command:
* - write arguments to EC[2:]
* - send 0 to CTRL then cmd to DATA
* 2. wait for EC
* 3. receive result: result may starts at EC[0] or EC[1]
*/
/* send command to EC and wait, command at cmd[0], args in cmd[2:] */
static enum cb_err ec_send_command(const u8 *cmd, int argc)
{
int result = CB_SUCCESS;
if (argc > 0) {
if (argc > 0x1e) {
printk(BIOS_ERR, "%s: argc too big.\n", __func__);
result = CB_ERR_ARG;
} else {
result = write_ec_regs(2, cmd + 2, argc);
}
}
outb(0, EC_CTRL);
outb(cmd[0], EC_DATA);
wait_ec();
return result;
}
/* receive result from EC[0:] */
enum cb_err mec5055_ec_command_0(u8 *buf, u8 cmd, int argc)
{
buf[0] = cmd;
enum cb_err res = ec_send_command(buf, argc);
if (res != CB_SUCCESS) {
printk(BIOS_ERR, "error: %s returns %d.\n", __func__, res);
return res;
}
return read_ec_regs(0, buf, 0x10);
}
/* receive result from EC[1:] */
enum cb_err mec5055_ec_command_1(u8 cmd, const u8 *cmd_buf, int argc, u8 *res_buf, int res_size)
{
if (argc >= 0x1e)
argc = 0x1e;
if (res_size >= 0x1f)
res_size = 0x1f;
enum cb_err res = write_ec_regs(2, cmd_buf, argc);
if (res != CB_SUCCESS) {
printk(BIOS_ERR, "error: %s returns %d.\n", __func__, res);
return res;
}
outb(0, EC_CTRL);
outb(cmd, EC_DATA);
wait_ec();
return read_ec_regs(1, res_buf, res_size);
}
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