| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <arch/io.h> |
| #include <console/console.h> |
| #include <device/smbus_def.h> |
| #include <device/smbus_host.h> |
| #include <types.h> |
| |
| #if CONFIG(DEBUG_SMBUS) |
| #define dprintk(args...) printk(BIOS_DEBUG, ##args) |
| #else |
| #define dprintk(args...) do {} while (0) |
| #endif |
| |
| /* SMBus register offsets. */ |
| #define SMBHSTSTAT 0x0 |
| #define SMBHSTCTL 0x2 |
| #define SMBHSTCMD 0x3 |
| #define SMBXMITADD 0x4 |
| #define SMBHSTDAT0 0x5 |
| #define SMBHSTDAT1 0x6 |
| #define SMBBLKDAT 0x7 |
| #define SMBTRNSADD 0x9 |
| #define SMBSLVDATA 0xa |
| #define SMLINK_PIN_CTL 0xe |
| #define SMBUS_PIN_CTL 0xf |
| #define SMBSLVCMD 0x11 |
| |
| #define SMB_RCV_SLVA SMBTRNSADD |
| |
| /* 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 void host_outb(uintptr_t base, u8 reg, u8 value) |
| { |
| outb(value, base + reg); |
| } |
| |
| static u8 host_inb(uintptr_t base, u8 reg) |
| { |
| return inb(base + reg); |
| } |
| |
| static void host_and_or(uintptr_t base, u8 reg, u8 mask, u8 or) |
| { |
| u8 value; |
| value = host_inb(base, reg); |
| value &= mask; |
| value |= or; |
| host_outb(base, reg, value); |
| } |
| |
| void smbus_host_reset(uintptr_t base) |
| { |
| /* Disable interrupt generation. */ |
| host_outb(base, SMBHSTCTL, 0); |
| |
| /* Clear any lingering errors, so transactions can run. */ |
| host_and_or(base, SMBHSTSTAT, 0xff, 0); |
| } |
| |
| void smbus_set_slave_addr(uintptr_t base, u8 slave_address) |
| { |
| host_outb(base, SMB_RCV_SLVA, slave_address); |
| } |
| |
| static int host_completed(u8 status) |
| { |
| if (status & SMBHSTSTS_HOST_BUSY) |
| return 0; |
| |
| /* These status bits do not imply completion of transaction. */ |
| status &= ~(SMBHSTSTS_BYTE_DONE | SMBHSTSTS_INUSE_STS | |
| SMBHSTSTS_SMBALERT_STS); |
| return status != 0; |
| } |
| |
| static int recover_master(uintptr_t 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) |
| { |
| /* These status bits do not imply errors. */ |
| status &= ~(SMBHSTSTS_BYTE_DONE | SMBHSTSTS_INUSE_STS | |
| SMBHSTSTS_SMBALERT_STS); |
| |
| if (status == SMBHSTSTS_INTR) |
| return 0; |
| |
| return SMBUS_ERROR; |
| } |
| |
| static int setup_command(uintptr_t base, u8 ctrl, u8 xmitadd) |
| { |
| unsigned int loops = SMBUS_TIMEOUT; |
| u8 host_busy; |
| |
| do { |
| smbus_delay(); |
| host_busy = host_inb(base, SMBHSTSTAT) & SMBHSTSTS_HOST_BUSY; |
| } while (--loops && host_busy); |
| |
| if (loops == 0) |
| return recover_master(base, SMBUS_WAIT_UNTIL_READY_TIMEOUT); |
| |
| /* Clear any lingering errors, so the transaction will run. */ |
| host_and_or(base, SMBHSTSTAT, 0xff, 0); |
| |
| /* Set up transaction */ |
| /* Disable interrupts */ |
| host_outb(base, SMBHSTCTL, ctrl); |
| |
| /* Set the device I'm talking to. */ |
| host_outb(base, SMBXMITADD, xmitadd); |
| |
| return 0; |
| } |
| |
| static int execute_command(uintptr_t base) |
| { |
| unsigned int loops = SMBUS_TIMEOUT; |
| u8 status; |
| |
| /* Start the command. */ |
| host_and_or(base, SMBHSTCTL, 0xff, SMBHSTCNT_START); |
| |
| /* 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 = host_inb(base, SMBHSTSTAT); |
| status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS); |
| } while (--loops && status == 0); |
| |
| if (loops == 0) |
| return recover_master(base, |
| SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT); |
| |
| return 0; |
| } |
| |
| static int complete_command(uintptr_t base) |
| { |
| unsigned int loops = SMBUS_TIMEOUT; |
| u8 status; |
| |
| do { |
| smbus_delay(); |
| status = host_inb(base, SMBHSTSTAT); |
| } while (--loops && !host_completed(status)); |
| |
| if (loops == 0) |
| return recover_master(base, |
| SMBUS_WAIT_UNTIL_DONE_TIMEOUT); |
| |
| return cb_err_from_stat(status); |
| } |
| |
| static int smbus_read_cmd(uintptr_t base, u8 ctrl, u8 device, u8 address) |
| { |
| int ret; |
| u16 word; |
| |
| /* Set up for a byte data read. */ |
| ret = setup_command(base, ctrl, XMIT_READ(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* Set the command/address... */ |
| host_outb(base, SMBHSTCMD, address); |
| |
| /* Clear the data bytes... */ |
| host_outb(base, SMBHSTDAT0, 0); |
| host_outb(base, SMBHSTDAT1, 0); |
| |
| /* Start the command */ |
| ret = execute_command(base); |
| if (ret < 0) |
| return ret; |
| |
| /* Poll for transaction completion */ |
| ret = complete_command(base); |
| if (ret < 0) |
| return ret; |
| |
| /* Read results of transaction */ |
| word = host_inb(base, SMBHSTDAT0); |
| if (ctrl == I801_WORD_DATA) |
| word |= host_inb(base, SMBHSTDAT1) << 8; |
| |
| return word; |
| } |
| |
| static int smbus_write_cmd(uintptr_t base, u8 ctrl, u8 device, u8 address, u16 data) |
| { |
| int ret; |
| |
| /* Set up for a byte data write. */ |
| ret = setup_command(base, ctrl, XMIT_WRITE(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* Set the command/address... */ |
| host_outb(base, SMBHSTCMD, address); |
| |
| /* Set the data bytes... */ |
| host_outb(base, SMBHSTDAT0, data & 0xff); |
| if (ctrl == I801_WORD_DATA) |
| host_outb(base, SMBHSTDAT1, data >> 8); |
| |
| /* Start the command */ |
| ret = execute_command(base); |
| if (ret < 0) |
| return ret; |
| |
| /* Poll for transaction completion */ |
| return complete_command(base); |
| } |
| |
| static int block_cmd_loop(uintptr_t base, u8 *buf, size_t max_bytes, int flags) |
| { |
| u8 status; |
| unsigned int loops = SMBUS_TIMEOUT; |
| int ret; |
| size_t 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) |
| host_outb(base, SMBHSTDAT0, max_bytes); |
| else |
| host_outb(base, SMBHSTDAT0, 0); |
| } |
| |
| /* Send first byte from buffer, bytes_sent increments after |
| * hardware acknowledges it. |
| */ |
| if (is_write_cmd) |
| host_outb(base, SMBBLKDAT, *buf++); |
| |
| /* Start the command */ |
| ret = execute_command(base); |
| if (ret < 0) |
| return ret; |
| |
| /* Poll for transaction completion */ |
| do { |
| status = host_inb(base, SMBHSTSTAT); |
| |
| if (status & SMBHSTSTS_BYTE_DONE) { /* Byte done */ |
| |
| if (is_write_cmd) { |
| bytes++; |
| if (bytes < max_bytes) |
| host_outb(base, SMBBLKDAT, *buf++); |
| } else { |
| if (bytes < max_bytes) |
| *buf++ = host_inb(base, SMBBLKDAT); |
| bytes++; |
| |
| /* Indicate that next byte is the last one. */ |
| if (sw_drives_nak && (bytes + 1 >= max_bytes)) { |
| host_and_or(base, SMBHSTCTL, 0xff, |
| SMBHSTCNT_LAST_BYTE); |
| } |
| |
| } |
| |
| /* Engine internally completes the transaction |
| * and clears HOST_BUSY flag once the byte count |
| * has been reached or LAST_BYTE was set. |
| */ |
| host_outb(base, SMBHSTSTAT, SMBHSTSTS_BYTE_DONE); |
| } |
| |
| } while (--loops && !host_completed(status)); |
| |
| dprintk("%s: status = %02x, len = %zd / %zd, loops = %d\n", |
| __func__, status, bytes, max_bytes, SMBUS_TIMEOUT - loops); |
| |
| if (loops == 0) |
| return recover_master(base, SMBUS_WAIT_UNTIL_DONE_TIMEOUT); |
| |
| ret = cb_err_from_stat(status); |
| if (ret < 0) |
| return ret; |
| |
| return bytes; |
| } |
| |
| int do_smbus_read_byte(uintptr_t base, u8 device, u8 address) |
| { |
| return smbus_read_cmd(base, I801_BYTE_DATA, device, address); |
| } |
| |
| int do_smbus_read_word(uintptr_t base, u8 device, u8 address) |
| { |
| return smbus_read_cmd(base, I801_WORD_DATA, device, address); |
| } |
| |
| int do_smbus_write_byte(uintptr_t base, u8 device, u8 address, u8 data) |
| { |
| return smbus_write_cmd(base, I801_BYTE_DATA, device, address, data); |
| } |
| |
| int do_smbus_write_word(uintptr_t base, u8 device, u8 address, u16 data) |
| { |
| return smbus_write_cmd(base, I801_WORD_DATA, device, address, data); |
| } |
| |
| int do_smbus_block_read(uintptr_t base, u8 device, u8 cmd, size_t 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(base, I801_BLOCK_DATA, XMIT_READ(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* Set the command/address... */ |
| host_outb(base, SMBHSTCMD, cmd); |
| |
| /* Execute block transaction. */ |
| ret = block_cmd_loop(base, buf, max_bytes, BLOCK_READ); |
| if (ret < 0) |
| return ret; |
| |
| /* Post-check we received complete message. */ |
| slave_bytes = host_inb(base, SMBHSTDAT0); |
| if (ret < slave_bytes) |
| return SMBUS_ERROR; |
| |
| return ret; |
| } |
| |
| int do_smbus_block_write(uintptr_t base, u8 device, u8 cmd, const size_t bytes, const u8 *buf) |
| { |
| int ret; |
| |
| if (bytes > SMBUS_BLOCK_MAXLEN) |
| return SMBUS_ERROR; |
| |
| /* Set up for a block data write. */ |
| ret = setup_command(base, I801_BLOCK_DATA, XMIT_WRITE(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* Set the command/address... */ |
| host_outb(base, SMBHSTCMD, cmd); |
| |
| /* Execute block transaction. */ |
| ret = block_cmd_loop(base, (u8 *)buf, bytes, BLOCK_WRITE); |
| if (ret < 0) |
| return ret; |
| |
| if (ret < bytes) |
| return SMBUS_ERROR; |
| |
| return ret; |
| } |
| |
| /* Only since ICH5 */ |
| static int has_i2c_read_command(void) |
| { |
| if (CONFIG(SOUTHBRIDGE_INTEL_I82371EB) || |
| CONFIG(SOUTHBRIDGE_INTEL_I82801DX)) |
| return 0; |
| return 1; |
| } |
| |
| int do_i2c_eeprom_read(uintptr_t base, u8 device, u8 offset, const size_t bytes, u8 *buf) |
| { |
| int ret; |
| |
| if (!has_i2c_read_command()) |
| return SMBUS_ERROR; |
| |
| /* 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(base, I801_I2C_BLOCK_DATA, |
| XMIT_WRITE(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* device offset */ |
| host_outb(base, SMBHSTDAT1, offset); |
| |
| /* Execute block transaction. */ |
| ret = block_cmd_loop(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; |
| } |
| |
| /* |
| * The caller is responsible of settings HOSTC I2C_EN bit prior to making this |
| * call! |
| */ |
| int do_i2c_block_write(uintptr_t base, u8 device, size_t bytes, u8 *buf) |
| { |
| u8 cmd; |
| int ret; |
| |
| if (!CONFIG(SOC_INTEL_BRASWELL)) |
| return SMBUS_ERROR; |
| |
| if (!bytes || (bytes > SMBUS_BLOCK_MAXLEN)) |
| return SMBUS_ERROR; |
| |
| /* Set up for a block data write. */ |
| ret = setup_command(base, I801_BLOCK_DATA, XMIT_WRITE(device)); |
| if (ret < 0) |
| return ret; |
| |
| /* |
| * In i2c mode SMBus controller sequence on bus will be: |
| * <SMBXINTADD> <SMBHSTDAT1> <SMBBLKDAT> .. <SMBBLKDAT> |
| * The SMBHSTCMD must be written also to ensure the SMBUs controller |
| * will generate the i2c sequence. |
| */ |
| cmd = *buf++; |
| bytes--; |
| host_outb(base, SMBHSTCMD, cmd); |
| host_outb(base, SMBHSTDAT1, cmd); |
| |
| /* Execute block transaction. */ |
| ret = block_cmd_loop(base, buf, bytes, BLOCK_WRITE); |
| if (ret < 0) |
| return ret; |
| |
| if (ret < bytes) |
| return SMBUS_ERROR; |
| |
| ret++; /* 1st byte has been written using SMBHSTDAT1 */ |
| return ret; |
| } |