ec.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <arch/io.h>
#include <console/console.h>
#include <device/device.h>
#include <delay.h>
 
#include "ec.h"
#include "chip.h"
 
static u16 ec_cmd_reg = 0;
static u16 ec_data_reg = 0;
 
static inline u8 __ec_read(u8 addr)
{
        outb(addr, ec_cmd_reg);
        return inb(ec_data_reg);
}
 
static inline void __ec_write(u8 addr, u8 data)
{
        outb(addr, ec_cmd_reg);
        outb(data, ec_data_reg);
}
 
static int ec_ready(void)
{
        u16 timeout = EC_TIMEOUT;
 
        if (!ec_cmd_reg || !ec_data_reg) {
                printk(BIOS_DEBUG, "Invalid ports: cmd=0x%x data=0x%x\n",
                       ec_cmd_reg, ec_data_reg);
                return -1;
        }
 
        while (__ec_read(EC_MAILBOX_COMMAND) != 0 && --timeout) {
                udelay(10);
                if ((timeout & 0xff) == 0)
                        printk(BIOS_SPEW, ".");
        }
        if (!timeout) {
                printk(BIOS_DEBUG, "Timeout waiting for EC to be ready.\n");
                return -1;
        }
        return 0;
}
 
int send_ec_command(u8 command)
{
        if (ec_ready() < 0)
                return -1;
        __ec_write(EC_MAILBOX_COMMAND, command);
        return ec_ready();
}
 
int send_ec_command_data(u8 command, u8 data)
{
        if (ec_ready() < 0)
                return -1;
        __ec_write(EC_MAILBOX_DATA, data);
        __ec_write(EC_MAILBOX_COMMAND, command);
        return ec_ready();
}
 
u8 read_ec_command_byte(u8 command)
{
        send_ec_command(command);
        return __ec_read(EC_MAILBOX_DATA);
}
 
u8 ec_read(u8 addr)
{
        if (send_ec_command_data(EC_RAM_READ, addr) < 0)
                return 0;
        return __ec_read(EC_MAILBOX_DATA);
}
 
int ec_write(u8 addr, u8 data)
{
        if (ec_ready() < 0)
                return -1;
        __ec_write(EC_MAILBOX_DATA, addr);
        __ec_write(EC_MAILBOX_DATA_H, data);
        __ec_write(EC_MAILBOX_COMMAND, EC_RAM_WRITE);
        return ec_ready();
}
 
void ec_set_bit(u8 addr, u8 bit)
{
        ec_write(addr, ec_read(addr) | (1 << bit));
}
 
void ec_clr_bit(u8 addr, u8 bit)
{
        ec_write(addr, ec_read(addr) &  ~(1 << bit));
}
 
void ec_set_ports(u16 cmd_reg, u16 data_reg)
{
        ec_cmd_reg = cmd_reg;
        ec_data_reg = data_reg;
}
 
static void mec1308_enable(struct device *dev)
{
        DEVTREE_CONST struct ec_smsc_mec1308_config *conf = dev->chip_info;
 
        if (conf->mailbox_port) {
                ec_cmd_reg = conf->mailbox_port;
                ec_data_reg = conf->mailbox_port + 1;
        }
}
 
struct chip_operations ec_smsc_mec1308_ops = {
        CHIP_NAME("SMSC MEC1308 EC Mailbox Interface")
        .enable_dev = mec1308_enable
};