diff options
Diffstat (limited to 'src/southbridge/amd/cs5535/cs5535_smbus.h')
| -rw-r--r-- | src/southbridge/amd/cs5535/cs5535_smbus.h | 59 |
1 files changed, 43 insertions, 16 deletions
diff --git a/src/southbridge/amd/cs5535/cs5535_smbus.h b/src/southbridge/amd/cs5535/cs5535_smbus.h index 2504f5dbef..9cf55ba29c 100644 --- a/src/southbridge/amd/cs5535/cs5535_smbus.h +++ b/src/southbridge/amd/cs5535/cs5535_smbus.h @@ -43,6 +43,8 @@ #define SMBUS_TIMEOUT (100*1000*10) #define SMBUS_STATUS_MASK 0xfbff +#define SMBUS_IO_BASE 0x6000 + static void smbus_delay(void) { outb(0x80, 0x80); @@ -75,6 +77,29 @@ static int smbus_start_condition(unsigned smbus_io_base) return loops?0:SMBUS_WAIT_UNTIL_READY_TIMEOUT; } +static int smbus_check_stop_condition(unsigned smbus_io_base) +{ + unsigned char val; + unsigned long loops; + loops = SMBUS_TIMEOUT; + /* check for SDA status */ + do { + smbus_delay(); + val = inw(smbus_io_base + SMB_CTRL1); + if ((val & SMB_CTRL1_STOP) == 0) { + break; + } + } while(--loops); + return loops?0:SMBUS_WAIT_UNTIL_READY_TIMEOUT; +} + +static int smbus_stop_condition(unsigned smbus_io_base) +{ + unsigned char val; + val = inb(smbus_io_base + SMB_CTRL1); + outb(SMB_CTRL1_STOP, smbus_io_base + SMB_CTRL1); +} + static int smbus_send_slave_address(unsigned smbus_io_base, unsigned char device) { unsigned char val; @@ -86,8 +111,8 @@ static int smbus_send_slave_address(unsigned smbus_io_base, unsigned char device /* check for bus conflict and NACK */ val = inb(smbus_io_base + SMB_STS); - if ( ((val & SMB_STS_BER) != 0) || - ((val & SMB_STS_NEGACK) != 0)) + if (((val & SMB_STS_BER) != 0) || + ((val & SMB_STS_NEGACK) != 0)) return SMBUS_ERROR; /* check for SDA status */ @@ -112,8 +137,8 @@ static int smbus_send_command(unsigned smbus_io_base, unsigned char command) /* check for bus conflict and NACK */ val = inb(smbus_io_base + SMB_STS); - if ( ((val & SMB_STS_BER) != 0) || - ((val & SMB_STS_NEGACK) != 0)) + if (((val & SMB_STS_BER) != 0) || + ((val & SMB_STS_NEGACK) != 0)) return SMBUS_ERROR; /* check for SDA status */ @@ -129,25 +154,27 @@ static int smbus_send_command(unsigned smbus_io_base, unsigned char command) static unsigned char do_smbus_read_byte(unsigned smbus_io_base, unsigned char device, unsigned char address) { - unsigned char val; + unsigned char val, val1; + + smbus_check_stop_condition(smbus_io_base); - if (smbus_start_condition(smbus_io_base) < 0) - print_debug("smbus error 1"); + smbus_start_condition(smbus_io_base); - if (smbus_send_slave_address(smbus_io_base, device) < 0) - print_debug("smbus error 2"); + smbus_send_slave_address(smbus_io_base, device); - if (smbus_send_command(smbus_io_base, address) < 0) - print_debug("smbus error 3"); + smbus_send_command(smbus_io_base, address); - if (smbus_start_condition(smbus_io_base) < 0) - print_debug("smbus error 4"); + smbus_start_condition(smbus_io_base); - if (smbus_send_slave_address(smbus_io_base, device | 0x01)) - print_debug("smbus error 5"); + smbus_send_slave_address(smbus_io_base, device | 0x01); + /* send NACK to slave */ val = inb(smbus_io_base + SMB_CTRL1); outb(val | SMB_CTRL1_ACK, smbus_io_base + SMB_CTRL1); - return inb(smbus_io_base + SMB_SDA); + val = inb(smbus_io_base + SMB_SDA); + + //smbus_stop_condition(smbus_io_base); + + return val; } |