diff options
Diffstat (limited to 'src/southbridge/via/vt8231/early_smbus.c')
| -rw-r--r-- | src/southbridge/via/vt8231/early_smbus.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/src/southbridge/via/vt8231/early_smbus.c b/src/southbridge/via/vt8231/early_smbus.c new file mode 100644 index 0000000000..7bf1267b75 --- /dev/null +++ b/src/southbridge/via/vt8231/early_smbus.c @@ -0,0 +1,295 @@ +#define SMBUS_IO_BASE 0x5000 + +#define SMBHSTSTAT 0x0 +#define SMBSLVSTAT 0x1 +#define SMBHSTCTL 0x2 +#define SMBHSTCMD 0x3 +#define SMBXMITADD 0x4 +#define SMBHSTDAT0 0x5 +#define SMBHSTDAT1 0x6 +#define SMBBLKDAT 0x7 +#define SMBSLVCTL 0x8 +#define SMBTRNSADD 0x9 +#define SMBSLVDATA 0xa +#define SMLINK_PIN_CTL 0xe +#define SMBUS_PIN_CTL 0xf + +/* Define register settings */ +#define HOST_RESET 0xff +#define READ_CMD 0x01 // 1 in the 0 bit of SMBHSTADD states to READ + + +#define SMBUS_TIMEOUT (100*1000*10) + +static void enable_smbus(void) +{ + device_t dev; + unsigned char c; + /* Power management controller */ + dev = pci_locate_device(PCI_ID(0x1106, 0x8235), 0); + + if (dev == PCI_DEV_INVALID) { + die("SMBUS controller not found\n"); + } + // set IO base address to SMBUS_IO_BASE + pci_write_config32(dev, 0x90, SMBUS_IO_BASE | 1); + + // Enable SMBus + c = pci_read_config8(dev, 0xd2); + c |= 5; + pci_write_config8(dev, 0xd2, c); + + /* make it work for I/O ... + */ + dev = pci_locate_device(PCI_ID(0x1106, 0x8231), 0); + c = pci_read_config8(dev, 4); + c |= 1; + pci_write_config8(dev, 4, c); + print_debug_hex8(c); + print_debug(" is the comm register\n"); + + print_debug("SMBus controller enabled\n"); +} + + +static inline void smbus_delay(void) +{ + outb(0x80, 0x80); +} + +static int smbus_wait_until_active(void) +{ + unsigned long loops; + loops = SMBUS_TIMEOUT; + do { + unsigned char val; + smbus_delay(); + val = inb(SMBUS_IO_BASE + SMBHSTSTAT); + if ((val & 1)) { + break; + } + } while (--loops); + return loops ? 0 : -4; +} + +static int smbus_wait_until_ready(void) +{ + unsigned long loops; + loops = SMBUS_TIMEOUT; + do { + unsigned char val; + smbus_delay(); + val = inb(SMBUS_IO_BASE + SMBHSTSTAT); + if ((val & 1) == 0) { + break; + } + if (loops == (SMBUS_TIMEOUT / 2)) { + outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT); + } + } while (--loops); + return loops ? 0 : -2; +} + +static int smbus_wait_until_done(void) +{ + unsigned long loops; + loops = SMBUS_TIMEOUT; + do { + unsigned char val; + smbus_delay(); + + val = inb(SMBUS_IO_BASE + SMBHSTSTAT); + if ((val & 1) == 0) { + break; + } + } while (--loops); + return loops ? 0 : -3; +} + +#if 0 +void smbus_reset(void) +{ + outb(HOST_RESET, SMBUS_IO_BASE + SMBHSTSTAT); + outb(HOST_RESET, SMBUS_IO_BASE + SMBHSTSTAT); + outb(HOST_RESET, SMBUS_IO_BASE + SMBHSTSTAT); + outb(HOST_RESET, SMBUS_IO_BASE + SMBHSTSTAT); + + smbus_wait_until_ready(); + print_debug("After reset status "); + print_debug_hex8(inb(SMBUS_IO_BASE + SMBHSTSTAT)); + print_debug("\n"); +} +#endif + +#if CONFIG_DEBUG_SMBUS +static void smbus_print_error(unsigned char host_status_register) +{ + + print_err("smbus_error: "); + print_err_hex8(host_status_register); + print_err("\n"); + if (host_status_register & (1 << 4)) { + print_err("Interrup/SMI# was Failed Bus Transaction\n"); + } + if (host_status_register & (1 << 3)) { + print_err("Bus Error\n"); + } + if (host_status_register & (1 << 2)) { + print_err("Device Error\n"); + } + if (host_status_register & (1 << 1)) { + print_err("Interrupt/SMI# was Successful Completion\n"); + } + if (host_status_register & (1 << 0)) { + print_err("Host Busy\n"); + } +} +#endif + +/* + * Copied from intel/i82801dbm early smbus code - suggested by rgm. + * Modifications/check against i2c-viapro driver code from linux-2.4.22 + * and VT8231 Reference Docs - mw. + */ +static int smbus_read_byte(unsigned device, unsigned address) +{ + unsigned char global_status_register; + unsigned char byte; + + if (smbus_wait_until_ready() < 0) { + outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT); + if (smbus_wait_until_ready() < 0) { + return -2; + } + } + + /* setup transaction */ + /* disable interrupts */ + outb(inb(SMBUS_IO_BASE + SMBHSTCTL) & 0xfe, SMBUS_IO_BASE + SMBHSTCTL); + /* set the device I'm talking too */ + outb(((device & 0x7f) << 1) | 1, SMBUS_IO_BASE + SMBXMITADD); + /* set the command/address... */ + outb(address & 0xFF, SMBUS_IO_BASE + SMBHSTCMD); + /* set up for a byte data read */ + outb((inb(SMBUS_IO_BASE + SMBHSTCTL) & 0xe3) | (0x2 << 2), SMBUS_IO_BASE + SMBHSTCTL); + + /* clear any lingering errors, so the transaction will run */ + outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT); + + /* clear the data byte... */ + outb(0, SMBUS_IO_BASE + SMBHSTDAT0); + + /* start a byte read, with interrupts disabled */ + outb((inb(SMBUS_IO_BASE + SMBHSTCTL) | 0x40), SMBUS_IO_BASE + SMBHSTCTL); + /* poll for it to start */ + if (smbus_wait_until_active() < 0) { + return -4; + } + + /* poll for transaction completion */ + if (smbus_wait_until_done() < 0) { + return -3; + } + + /* Ignore the Host Busy & Command Complete ? */ + global_status_register = inb(SMBUS_IO_BASE + SMBHSTSTAT) & ~((1 << 1) | (1 << 0)); + + /* read results of transaction */ + byte = inb(SMBUS_IO_BASE + SMBHSTDAT0); + + if (global_status_register != 0) { + return -1; + } + return byte; +} + +#if 0 +/* SMBus routines borrowed from VIA's Trident Driver */ +/* this works, so I am not going to touch it for now -- rgm */ +static unsigned char smbus_read_byte(unsigned char devAdr, unsigned char bIndex) +{ + unsigned int i; + unsigned char bData; + unsigned char sts = 0; + + /* clear host status */ + outb(0xff, SMBUS_IO_BASE); + + /* check SMBUS ready */ + for (i = 0; i < SMBUS_TIMEOUT; i++) + if ((inb(SMBUS_IO_BASE) & 0x01) == 0) + break; + + /* set host command */ + outb(bIndex, SMBUS_IO_BASE + 3); + + /* set slave address */ + outb(devAdr | 0x01, SMBUS_IO_BASE + 4); + + /* start */ + outb(0x48, SMBUS_IO_BASE + 2); + + /* SMBUS Wait Ready */ + for (i = 0; i < SMBUS_TIMEOUT; i++) + if (((sts = inb(SMBUS_IO_BASE)) & 0x01) == 0) + break; + if ((sts & ~3) != 0) { + smbus_print_error(sts); + return 0; + } + bData = inb(SMBUS_IO_BASE + 5); + + return bData; + +} +#endif +/* for reference, here is the fancier version which we will use at some + * point + */ +# if 0 +int smbus_read_byte(unsigned device, unsigned address, unsigned char *result) +{ + unsigned char host_status_register; + unsigned char byte; + + reset(); + + smbus_wait_until_ready(); + + /* setup transaction */ + /* disable interrupts */ + outb(inb(SMBUS_IO_BASE + SMBHSTCTL) & (~1), SMBUS_IO_BASE + SMBHSTCTL); + /* set the device I'm talking too */ + outb(((device & 0x7f) << 1) | 1, SMBUS_IO_BASE + SMBXMITADD); + /* set the command/address... */ + outb(address & 0xFF, SMBUS_IO_BASE + SMBHSTCMD); + /* set up for a byte data read */ + outb((inb(SMBUS_IO_BASE + SMBHSTCTL) & 0xE3) | (0x2 << 2), SMBUS_IO_BASE + SMBHSTCTL); + + /* clear any lingering errors, so the transaction will run */ + outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT); + + /* clear the data byte... */ + outb(0, SMBUS_IO_BASE + SMBHSTDAT0); + + /* start the command */ + outb((inb(SMBUS_IO_BASE + SMBHSTCTL) | 0x40), SMBUS_IO_BASE + SMBHSTCTL); + + /* poll for transaction completion */ + smbus_wait_until_done(); + + host_status_register = inb(SMBUS_IO_BASE + SMBHSTSTAT); + + /* Ignore the In Use Status... */ + host_status_register &= ~(1 << 6); + + /* read results of transaction */ + byte = inb(SMBUS_IO_BASE + SMBHSTDAT0); + smbus_print_error(byte); + + *result = byte; + return host_status_register != 0x02; +} + + +#endif |