src/ec/smsc/mec1308/ec.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <arch/io.h>
   4 #include <console/console.h>
   5 #include <device/device.h>
   6 #include <delay.h>
   7
   8 #include "ec.h"
   9 #include "chip.h"
  10
  11 static u16 ec_cmd_reg = 0;
  12 static u16 ec_data_reg = 0;
  13
  14 static inline u8 __ec_read(u8 addr)
  15 {
  16         outb(addr, ec_cmd_reg);
  17         return inb(ec_data_reg);
  18 }
  19
  20 static inline void __ec_write(u8 addr, u8 data)
  21 {
  22         outb(addr, ec_cmd_reg);
  23         outb(data, ec_data_reg);
  24 }
  25
  26 static int ec_ready(void)
  27 {
  28         u16 timeout = EC_TIMEOUT;
  29
  30         if (!ec_cmd_reg || !ec_data_reg) {
  31                 printk(BIOS_DEBUG, "Invalid ports: cmd=0x%x data=0x%x\n",
  32                        ec_cmd_reg, ec_data_reg);
  33                 return -1;
  34         }
  35
  36         while (__ec_read(EC_MAILBOX_COMMAND) != 0 && --timeout) {
  37                 udelay(10);
  38                 if ((timeout & 0xff) == 0)
  39                         printk(BIOS_SPEW, ".");
  40         }
  41         if (!timeout) {
  42                 printk(BIOS_DEBUG, "Timeout waiting for EC to be ready.\n");
  43                 return -1;
  44         }
  45         return 0;
  46 }
  47
  48 int send_ec_command(u8 command)
  49 {
  50         if (ec_ready() < 0)
  51                 return -1;
  52         __ec_write(EC_MAILBOX_COMMAND, command);
  53         return ec_ready();
  54 }
  55
  56 int send_ec_command_data(u8 command, u8 data)
  57 {
  58         if (ec_ready() < 0)
  59                 return -1;
  60         __ec_write(EC_MAILBOX_DATA, data);
  61         __ec_write(EC_MAILBOX_COMMAND, command);
  62         return ec_ready();
  63 }
  64
  65 u8 read_ec_command_byte(u8 command)
  66 {
  67         send_ec_command(command);
  68         return __ec_read(EC_MAILBOX_DATA);
  69 }
  70
  71 u8 ec_read(u8 addr)
  72 {
  73         if (send_ec_command_data(EC_RAM_READ, addr) < 0)
  74                 return 0;
  75         return __ec_read(EC_MAILBOX_DATA);
  76 }
  77
  78 int ec_write(u8 addr, u8 data)
  79 {
  80         if (ec_ready() < 0)
  81                 return -1;
  82         __ec_write(EC_MAILBOX_DATA, addr);
  83         __ec_write(EC_MAILBOX_DATA_H, data);
  84         __ec_write(EC_MAILBOX_COMMAND, EC_RAM_WRITE);
  85         return ec_ready();
  86 }
  87
  88 void ec_set_bit(u8 addr, u8 bit)
  89 {
  90         ec_write(addr, ec_read(addr) | (1 << bit));
  91 }
  92
  93 void ec_clr_bit(u8 addr, u8 bit)
  94 {
  95         ec_write(addr, ec_read(addr) &  ~(1 << bit));
  96 }
  97
  98 void ec_set_ports(u16 cmd_reg, u16 data_reg)
  99 {
 100         ec_cmd_reg = cmd_reg;
 101         ec_data_reg = data_reg;
 102 }
 103
 104 static void mec1308_enable(struct device *dev)
 105 {
 106         DEVTREE_CONST struct ec_smsc_mec1308_config *conf = dev->chip_info;
 107
 108         if (conf->mailbox_port) {
 109                 ec_cmd_reg = conf->mailbox_port;
 110                 ec_data_reg = conf->mailbox_port + 1;
 111         }
 112 }
 113
 114 struct chip_operations ec_smsc_mec1308_ops = {
 115         .name = "SMSC MEC1308 EC Mailbox Interface",
 116         .enable_dev = mec1308_enable
 117 };