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Diffstat (limited to 'src/southbridge/intel/esb6300/smbus.h')
-rw-r--r--src/southbridge/intel/esb6300/smbus.h101
1 files changed, 101 insertions, 0 deletions
diff --git a/src/southbridge/intel/esb6300/smbus.h b/src/southbridge/intel/esb6300/smbus.h
new file mode 100644
index 0000000000..4f4ec5c999
--- /dev/null
+++ b/src/southbridge/intel/esb6300/smbus.h
@@ -0,0 +1,101 @@
+#include <device/smbus_def.h>
+
+#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 SMBUS_TIMEOUT (100*1000*10)
+
+#include <delay.h>
+
+static int smbus_wait_until_ready(unsigned smbus_io_base)
+{
+ unsigned loops = SMBUS_TIMEOUT;
+ unsigned char byte;
+ do {
+ udelay(100);
+ if (--loops == 0)
+ break;
+ byte = inb(smbus_io_base + SMBHSTSTAT);
+ } while(byte & 1);
+ return loops?0:-1;
+}
+
+static int smbus_wait_until_done(unsigned smbus_io_base)
+{
+ unsigned loops = SMBUS_TIMEOUT;
+ unsigned char byte;
+ do {
+ udelay(100);
+ if (--loops == 0)
+ break;
+ byte = inb(smbus_io_base + SMBHSTSTAT);
+ } while((byte & 1) || (byte & ~((1<<6)|(1<<0))) == 0);
+ return loops?0:-1;
+}
+
+static inline int smbus_wait_until_blk_done(unsigned smbus_io_base)
+{
+ unsigned loops = SMBUS_TIMEOUT;
+ unsigned char byte;
+ do {
+ udelay(100);
+ if (--loops == 0)
+ break;
+ byte = inb(smbus_io_base + SMBHSTSTAT);
+ } while((byte&(1<<7)) == 0);
+ return loops?0:-1;
+}
+
+static int do_smbus_read_byte(unsigned smbus_io_base, unsigned device, unsigned address)
+{
+ unsigned char global_status_register;
+ unsigned char byte;
+
+ if (smbus_wait_until_ready(smbus_io_base) < 0) {
+ return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
+ }
+ /* 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 */
+ if (smbus_wait_until_done(smbus_io_base) < 0) {
+ return SMBUS_WAIT_UNTIL_DONE_TIMEOUT;
+ }
+
+ global_status_register = inb(smbus_io_base + SMBHSTSTAT);
+
+ /* Ignore the In Use Status... */
+ global_status_register &= ~(3 << 5);
+
+ /* read results of transaction */
+ byte = inb(smbus_io_base + SMBHSTDAT0);
+ if (global_status_register != (1 << 1)) {
+ return SMBUS_ERROR;
+ }
+ return byte;
+}
+