| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 2005 Yinghai Lu <yinghailu@gmail.com> |
| * Copyright (C) 2009 coresystems GmbH |
| * Copyright (C) 2013 Vladimir Serbinenko |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <arch/io.h> |
| #include <console/console.h> |
| #include <device/smbus_def.h> |
| #include <stdlib.h> |
| #include "smbus.h" |
| |
| |
| #if IS_ENABLED(CONFIG_DEBUG_SMBUS) |
| #define dprintk(args...) printk(BIOS_DEBUG, ##args) |
| #else |
| #define dprintk(args...) do {} while (0) |
| #endif |
| |
| /* I801 command constants */ |
| #define I801_QUICK (0 << 2) |
| #define I801_BYTE (1 << 2) |
| #define I801_BYTE_DATA (2 << 2) |
| #define I801_WORD_DATA (3 << 2) |
| #define I801_BLOCK_DATA (5 << 2) |
| #define I801_I2C_BLOCK_DATA (6 << 2) /* ICH5 and later */ |
| |
| /* I801 Host Control register bits */ |
| #define SMBHSTCNT_INTREN (1 << 0) |
| #define SMBHSTCNT_KILL (1 << 1) |
| #define SMBHSTCNT_LAST_BYTE (1 << 5) |
| #define SMBHSTCNT_START (1 << 6) |
| #define SMBHSTCNT_PEC_EN (1 << 7) /* ICH3 and later */ |
| |
| /* I801 Hosts Status register bits */ |
| #define SMBHSTSTS_BYTE_DONE (1 << 7) |
| #define SMBHSTSTS_INUSE_STS (1 << 6) |
| #define SMBHSTSTS_SMBALERT_STS (1 << 5) |
| #define SMBHSTSTS_FAILED (1 << 4) |
| #define SMBHSTSTS_BUS_ERR (1 << 3) |
| #define SMBHSTSTS_DEV_ERR (1 << 2) |
| #define SMBHSTSTS_INTR (1 << 1) |
| #define SMBHSTSTS_HOST_BUSY (1 << 0) |
| |
| /* For SMBXMITADD register. */ |
| #define XMIT_WRITE(dev) (((dev) << 1) | 0) |
| #define XMIT_READ(dev) (((dev) << 1) | 1) |
| |
| #define SMBUS_TIMEOUT (10 * 1000 * 100) |
| #define SMBUS_BLOCK_MAXLEN 32 |
| |
| /* block_cmd_loop flags */ |
| #define BLOCK_READ 0 |
| #define BLOCK_WRITE (1 << 0) |
| #define BLOCK_I2C (1 << 1) |
| |
| static void smbus_delay(void) |
| { |
| inb(0x80); |
| } |
| |
| static int host_completed(u8 status) |
| { |
| if (status & SMBHSTSTS_HOST_BUSY) |
| return 0; |
| status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS); |
| return status != 0; |
| } |
| |
| static int recover_master(int smbus_base, int ret) |
| { |
| /* TODO: Depending of the failure, drive KILL transaction |
| * or force soft reset on SMBus master controller. |
| */ |
| printk(BIOS_ERR, "SMBus: Fatal master timeout (%d)\n", ret); |
| return ret; |
| } |
| |
| static int cb_err_from_stat(u8 status) |
| { |
| /* Ignore the "In Use" status... */ |
| status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS); |
| |
| if (status == SMBHSTSTS_INTR) |
| return 0; |
| |
| return SMBUS_ERROR; |
| } |
| |
| static int setup_command(unsigned int smbus_base, u8 ctrl, u8 xmitadd) |
| { |
| unsigned int loops = SMBUS_TIMEOUT; |
| u8 host_busy; |
| |
| do { |
| smbus_delay(); |
| host_busy = inb(smbus_base + SMBHSTSTAT) & SMBHSTSTS_HOST_BUSY; |
| } while (--loops && host_busy); |
| |
| if (loops == 0) |
| return recover_master(smbus_base, |
| SMBUS_WAIT_UNTIL_READY_TIMEOUT); |
| |
| /* Clear any lingering errors, so the transaction will run. */ |
| outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT); |
| |
| /* Set up transaction */ |
| /* Disable interrupts */ |
| outb(ctrl, (smbus_base + SMBHSTCTL)); |
| |
| /* Set the device I'm talking to. */ |
| outb(xmitadd, smbus_base + SMBXMITADD); |
| |
| return 0; |
| } |
| |
| static int execute_command(unsigned int smbus_base) |
| { |
| unsigned int loops = SMBUS_TIMEOUT; |
| u8 status; |
| |
| /* Start the command. */ |
| outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START), |
| smbus_base + SMBHSTCTL); |
| |
| /* Poll for it to start. */ |
| do { |
| smbus_delay(); |
| |
| /* If we poll too slow, we could miss HOST_BUSY flag |
| * set and detect INTR or x_ERR flags instead here. |
| */ |
| status = inb(smbus_base + SMBHSTSTAT); |
| status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS); |
| } while (--loops && status == 0); |
| |
| if (loops == 0) |
| return recover_master(smbus_base, |
| SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT); |
| |
| return 0; |
| } |
| |
| static int complete_command(unsigned int smbus_base) |
| { |
| unsigned int loops = SMBUS_TIMEOUT; |
| u8 status; |
| |
| do { |
| smbus_delay(); |
| status = inb(smbus_base + SMBHSTSTAT); |
| } while (--loops && !host_completed(status)); |
| |
| if (loops == 0) |
| return recover_master(smbus_base, |
| SMBUS_WAIT_UNTIL_DONE_TIMEOUT); |
| |
| return cb_err_from_stat(status); |
| } |
| |
| int do_smbus_read_byte(unsigned int smbus_base, u8 device, |
| unsigned int address) |
| { |
| int ret; |
| u8 byte; |
| |
| /* Set up for a byte data read. */ |
| ret = setup_command(smbus_base, I801_BYTE_DATA, XMIT_READ(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* Set the command/address... */ |
| outb(address, smbus_base + SMBHSTCMD); |
| |
| /* Clear the data byte... */ |
| outb(0, smbus_base + SMBHSTDAT0); |
| |
| /* Start the command */ |
| ret = execute_command(smbus_base); |
| if (ret < 0) |
| return ret; |
| |
| /* Poll for transaction completion */ |
| ret = complete_command(smbus_base); |
| if (ret < 0) |
| return ret; |
| |
| /* Read results of transaction */ |
| byte = inb(smbus_base + SMBHSTDAT0); |
| return byte; |
| } |
| |
| int do_smbus_write_byte(unsigned int smbus_base, u8 device, |
| unsigned int address, unsigned int data) |
| { |
| int ret; |
| |
| /* Set up for a byte data write. */ |
| ret = setup_command(smbus_base, I801_BYTE_DATA, XMIT_WRITE(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* Set the command/address... */ |
| outb(address, smbus_base + SMBHSTCMD); |
| |
| /* Set the data byte... */ |
| outb(data, smbus_base + SMBHSTDAT0); |
| |
| /* Start the command */ |
| ret = execute_command(smbus_base); |
| if (ret < 0) |
| return ret; |
| |
| /* Poll for transaction completion */ |
| return complete_command(smbus_base); |
| } |
| |
| static int block_cmd_loop(unsigned int smbus_base, |
| u8 *buf, const unsigned int max_bytes, int flags) |
| { |
| u8 status; |
| unsigned int loops = SMBUS_TIMEOUT; |
| int ret, bytes = 0; |
| int is_write_cmd = flags & BLOCK_WRITE; |
| int sw_drives_nak = flags & BLOCK_I2C; |
| |
| /* Hardware limitations. */ |
| if (flags == (BLOCK_WRITE | BLOCK_I2C)) |
| return SMBUS_ERROR; |
| |
| /* Set number of bytes to transfer. */ |
| /* Reset number of bytes to transfer so we notice later it |
| * was really updated with the transaction. */ |
| if (!sw_drives_nak) { |
| if (is_write_cmd) |
| outb(max_bytes, smbus_base + SMBHSTDAT0); |
| else |
| outb(0, smbus_base + SMBHSTDAT0); |
| } |
| |
| /* Send first byte from buffer, bytes_sent increments after |
| * hardware acknowledges it. |
| */ |
| if (is_write_cmd) |
| outb(*buf++, smbus_base + SMBBLKDAT); |
| |
| /* Start the command */ |
| ret = execute_command(smbus_base); |
| if (ret < 0) |
| return ret; |
| |
| /* Poll for transaction completion */ |
| do { |
| status = inb(smbus_base + SMBHSTSTAT); |
| |
| if (status & SMBHSTSTS_BYTE_DONE) { /* Byte done */ |
| |
| if (is_write_cmd) { |
| bytes++; |
| if (bytes < max_bytes) |
| outb(*buf++, smbus_base + SMBBLKDAT); |
| } else { |
| if (bytes < max_bytes) |
| *buf++ = inb(smbus_base + SMBBLKDAT); |
| bytes++; |
| |
| /* Indicate that next byte is the last one. */ |
| if (sw_drives_nak && (bytes + 1 >= max_bytes)) { |
| outb(inb(smbus_base + SMBHSTCTL) |
| | SMBHSTCNT_LAST_BYTE, |
| smbus_base + SMBHSTCTL); |
| } |
| |
| } |
| |
| /* Engine internally completes the transaction |
| * and clears HOST_BUSY flag once the byte count |
| * has been reached or LAST_BYTE was set. |
| */ |
| outb(SMBHSTSTS_BYTE_DONE, smbus_base + SMBHSTSTAT); |
| } |
| |
| } while (--loops && !host_completed(status)); |
| |
| dprintk("%s: status = %02x, len = %d / %d, loops = %d\n", |
| __func__, status, bytes, max_bytes, SMBUS_TIMEOUT - loops); |
| |
| if (loops == 0) |
| return recover_master(smbus_base, |
| SMBUS_WAIT_UNTIL_DONE_TIMEOUT); |
| |
| ret = cb_err_from_stat(status); |
| if (ret < 0) |
| return ret; |
| |
| return bytes; |
| } |
| |
| int do_smbus_block_read(unsigned int smbus_base, u8 device, u8 cmd, |
| unsigned int max_bytes, u8 *buf) |
| { |
| int ret, slave_bytes; |
| |
| max_bytes = MIN(SMBUS_BLOCK_MAXLEN, max_bytes); |
| |
| /* Set up for a block data read. */ |
| ret = setup_command(smbus_base, I801_BLOCK_DATA, XMIT_READ(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* Set the command/address... */ |
| outb(cmd, smbus_base + SMBHSTCMD); |
| |
| /* Execute block transaction. */ |
| ret = block_cmd_loop(smbus_base, buf, max_bytes, BLOCK_READ); |
| if (ret < 0) |
| return ret; |
| |
| /* Post-check we received complete message. */ |
| slave_bytes = inb(smbus_base + SMBHSTDAT0); |
| if (ret < slave_bytes) |
| return SMBUS_ERROR; |
| |
| return ret; |
| } |
| |
| int do_smbus_block_write(unsigned int smbus_base, u8 device, u8 cmd, |
| const unsigned int bytes, const u8 *buf) |
| { |
| int ret; |
| |
| if (bytes > SMBUS_BLOCK_MAXLEN) |
| return SMBUS_ERROR; |
| |
| /* Set up for a block data write. */ |
| ret = setup_command(smbus_base, I801_BLOCK_DATA, XMIT_WRITE(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* Set the command/address... */ |
| outb(cmd, smbus_base + SMBHSTCMD); |
| |
| /* Execute block transaction. */ |
| ret = block_cmd_loop(smbus_base, (u8 *)buf, bytes, BLOCK_WRITE); |
| if (ret < 0) |
| return ret; |
| |
| if (ret < bytes) |
| return SMBUS_ERROR; |
| |
| return ret; |
| } |
| |
| /* Only since ICH5 */ |
| int do_i2c_block_read(unsigned int smbus_base, u8 device, |
| unsigned int offset, const unsigned int bytes, u8 *buf) |
| { |
| int ret; |
| |
| /* Set up for a i2c block data read. |
| * |
| * FIXME: Address parameter changes to XMIT_READ(device) with |
| * some revision of PCH. Presumably hardware revisions that |
| * do not have i2c block write support internally set LSB. |
| */ |
| ret = setup_command(smbus_base, I801_I2C_BLOCK_DATA, |
| XMIT_WRITE(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* device offset */ |
| outb(offset, smbus_base + SMBHSTDAT1); |
| |
| /* Execute block transaction. */ |
| ret = block_cmd_loop(smbus_base, buf, bytes, BLOCK_READ | BLOCK_I2C); |
| if (ret < 0) |
| return ret; |
| |
| /* Post-check we received complete message. */ |
| if (ret < bytes) |
| return SMBUS_ERROR; |
| |
| return ret; |
| } |