smihandler.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
 
/*
 * SMI handler -- mostly takes care of SMIs from the EC
 */
 
#include <arch/io.h>
#include <console/console.h>
#include <cpu/x86/smm.h>
#include <ec/compal/ene932/ec.h>
#include <southbridge/amd/agesa/hudson/hudson.h>
#include <southbridge/amd/agesa/hudson/smi.h>
 
#include "ec.h"
 
#define ACPI_PM1_CNT_SLEEP(state) ((1 << 13) | (state & 0x7) << 10)
 
enum sleep_states {
        S0 = 0,
        S1 = 1,
        S3 = 3,
        S4 = 4,
        S5 = 5,
};
 
enum ec_smi_event {
        EC_SMI_EVENT_IDLE = 0x80,
        EC_SMI_BATTERY_LOW = 0xb3,
};
 
/* Tell EC to operate in APM mode. Events generate SMIs instead of SCIs */
static void ec_enter_apm_mode(void)
{
        ec_kbc_write_cmd(0x59);
        ec_kbc_write_ib(0xE9);
}
/* Tell EC to operate in ACPI mode, thus generating SCIs on events, not SMIs */
static void ec_enter_acpi_mode(void)
{
        ec_kbc_write_cmd(0x59);
        ec_kbc_write_ib(0xE8);
}
 
static uint8_t ec_get_smi_event(void)
{
        ec_kbc_write_cmd(0x56);
        return ec_kbc_read_ob();
}
 
static void ec_process_smi(uint8_t src)
{
        /* Reading the SMI source satisfies the EC in terms of responding to
         * the event, regardless of whether we take an action or not.
         */
 
        switch (src) {
        case EC_SMI_BATTERY_LOW:
                printk(BIOS_DEBUG, "Battery low. Shutting down\n");
                outl(ACPI_PM1_CNT_SLEEP(S5), ACPI_PM1_CNT_BLK);
                break;
        default:
                printk(BIOS_DEBUG, "EC_SMI event 0x%x\n", src);
        }
}
 
static void handle_ec_smi(void)
{
        uint8_t src;
 
        while ((src = ec_get_smi_event()) != EC_SMI_EVENT_IDLE)
                ec_process_smi(src);
}
 
static void handle_lid_smi(void)
{
        /* Only triggered in non-ACPI mode on lid close. */
        outl(ACPI_PM1_CNT_SLEEP(S4), ACPI_PM1_CNT_BLK);
}
 
int mainboard_smi_apmc(uint8_t data)
{
        switch (data) {
        case ACPI_SMI_CMD_ENABLE:
                printk(BIOS_DEBUG, "Enable ACPI mode\n");
                ec_enter_acpi_mode();
                hudson_disable_gevent_smi(EC_LID_GEVENT);
                break;
        case ACPI_SMI_CMD_DISABLE:
                printk(BIOS_DEBUG, "Disable ACPI mode\n");
                ec_enter_apm_mode();
                hudson_configure_gevent_smi(EC_LID_GEVENT, SMI_MODE_SMI,
                                            SMI_LVL_LOW);
                break;
        default:
                printk(BIOS_DEBUG, "Unhandled ACPI command: 0x%x\n", data);
        }
        return 0;
}
 
void mainboard_smi_gpi(uint32_t gpi_sts)
{
        if (gpi_sts & (1 << EC_SMI_GEVENT))
                handle_ec_smi();
        if (gpi_sts & (1 << EC_LID_GEVENT))
                handle_lid_smi();
}