diff options
Diffstat (limited to 'hw/xfree86/i2c/xf86i2c.c')
| -rw-r--r-- | hw/xfree86/i2c/xf86i2c.c | 863 |
1 files changed, 863 insertions, 0 deletions
diff --git a/hw/xfree86/i2c/xf86i2c.c b/hw/xfree86/i2c/xf86i2c.c new file mode 100644 index 000000000..494f9303b --- /dev/null +++ b/hw/xfree86/i2c/xf86i2c.c @@ -0,0 +1,863 @@ +/* + * Copyright (C) 1998 Itai Nahshon, Michael Schimek + * + * The original code was derived from and inspired by + * the I2C driver from the Linux kernel. + * (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de> + */ + +/* $XFree86: xc/programs/Xserver/hw/xfree86/i2c/xf86i2c.c,v 1.13 2002/09/16 18:06:07 eich Exp $ */ + +#if 1 +#include "misc.h" +#include "xf86.h" +#include "xf86_ansic.h" +#include "xf86_OSproc.h" + +#include "X.h" +#include "Xproto.h" +#include "scrnintstr.h" +#include "regionstr.h" +#include "windowstr.h" +#include "pixmapstr.h" +#include "validate.h" +#include "resource.h" +#include "gcstruct.h" +#include "dixstruct.h" +#else +typedef int Bool; +typedef void *Pointer; +#define NULL ((void *)0) +#define X_DEFAULT 0 +#define TRUE 1 +#define FALSE 0 +#endif + +#include "xf86i2c.h" + +#define I2C_TIMEOUT(x) /*(x)*/ /* Report timeouts */ +#define I2C_TRACE(x) /*(x)*/ /* Report progress */ + +/* Set which OSs have bad gettimeofday resolution. */ +#if defined(SVR4) && !defined(sun) +#define BAD_GETTIMEOFDAY_RESOLUTION +#endif + + +/* This is the default I2CUDelay function if not supplied by the driver. + * High level I2C interfaces implementing the bus protocol in hardware + * should supply this function too. + * + * Delay execution at least usec microseconds. + * All values 0 to 1e6 inclusive must be expected. + */ + +#ifdef BAD_GETTIMEOFDAY_RESOLUTION +/* + * This is temporary until a better, portable + * way is found. Adjust bogo_usec to match CPU speed. + */ +static int bogo_usec = 500; + +static void +I2CUDelay(I2CBusPtr b, int usec) +{ + volatile long i; + + if (usec > 0) + for (i = usec * bogo_usec; i > 0; i--) + /* (perhaps hw delay action) */; +} +#else +static void +I2CUDelay(I2CBusPtr b, int usec) +{ + long b_secs, b_usecs; + long a_secs, a_usecs; + long d_secs, d_usecs; + long diff; + + if (usec > 0) { + xf86getsecs(&b_secs, &b_usecs); + do { + /* It would be nice to use {xf86}usleep, + * but usleep (1) takes >10000 usec ! + */ + xf86getsecs(&a_secs, &a_usecs); + d_secs = (a_secs - b_secs); + d_usecs = (a_usecs - b_usecs); + diff = d_secs*1000000 + d_usecs; + } while (diff>0 && diff< (usec + 1)); + } +} +#endif + +/* Most drivers will register just with GetBits/PutBits functions. + * The following functions implement a software I2C protocol + * by using the promitive functions given by the driver. + * ================================================================ + * + * It is assumed that there is just one master on the I2C bus, therefore + * there is no explicit test for conflits. + */ + +#define RISEFALLTIME 2 /* usec, actually 300 to 1000 ns according to the i2c specs */ + +/* Some devices will hold SCL low to slow down the bus or until + * ready for transmission. + * + * This condition will be noticed when the master tries to raise + * the SCL line. You can set the timeout to zero if the slave device + * does not support this clock synchronization. + */ + +static Bool +I2CRaiseSCL(I2CBusPtr b, int sda, int timeout) +{ + int i, scl; + + b->I2CPutBits(b, 1, sda); + b->I2CUDelay(b, b->RiseFallTime); + + for (i = timeout; i > 0; i -= b->RiseFallTime) { + b->I2CGetBits(b, &scl, &sda); + if (scl) break; + b->I2CUDelay(b, b->RiseFallTime); + } + + if (i <= 0) { + I2C_TIMEOUT(ErrorF("[I2CRaiseSCL(<%s>, %d, %d) timeout]", b->BusName, sda, timeout)); + return FALSE; + } + + return TRUE; +} + +/* Send a start signal on the I2C bus. The start signal notifies + * devices that a new transaction is initiated by the bus master. + * + * The start signal is always followed by a slave address. + * Slave addresses are 8+ bits. The first 7 bits identify the + * device and the last bit signals if this is a read (1) or + * write (0) operation. + * + * There may be more than one start signal on one transaction. + * This happens for example on some devices that allow reading + * of registers. First send a start bit followed by the device + * address (with the last bit 0) and the register number. Then send + * a new start bit with the device address (with the last bit 1) + * and then read the value from the device. + * + * Note this is function does not implement a multiple master + * arbitration procedure. + */ + +static Bool +I2CStart(I2CBusPtr b, int timeout) +{ + if (!I2CRaiseSCL(b, 1, timeout)) + return FALSE; + + b->I2CPutBits(b, 1, 0); + b->I2CUDelay(b, b->HoldTime); + b->I2CPutBits(b, 0, 0); + b->I2CUDelay(b, b->HoldTime); + + I2C_TRACE(ErrorF("\ni2c: <")); + + return TRUE; +} + +/* This is the default I2CStop function if not supplied by the driver. + * + * Signal devices on the I2C bus that a transaction on the + * bus has finished. There may be more than one start signal + * on a transaction but only one stop signal. + */ + +static void +I2CStop(I2CDevPtr d) +{ + I2CBusPtr b = d->pI2CBus; + + b->I2CPutBits(b, 0, 0); + b->I2CUDelay(b, b->RiseFallTime); + + b->I2CPutBits(b, 1, 0); + b->I2CUDelay(b, b->HoldTime); + b->I2CPutBits(b, 1, 1); + b->I2CUDelay(b, b->HoldTime); + + I2C_TRACE(ErrorF(">\n")); +} + +/* Write/Read a single bit to/from a device. + * Return FALSE if a timeout occurs. + */ + +static Bool +I2CWriteBit(I2CBusPtr b, int sda, int timeout) +{ + Bool r; + + b->I2CPutBits(b, 0, sda); + b->I2CUDelay(b, b->RiseFallTime); + + r = I2CRaiseSCL(b, sda, timeout); + b->I2CUDelay(b, b->HoldTime); + + b->I2CPutBits(b, 0, sda); + b->I2CUDelay(b, b->HoldTime); + + return r; +} + +static Bool +I2CReadBit(I2CBusPtr b, int *psda, int timeout) +{ + Bool r; + int scl; + + r = I2CRaiseSCL(b, 1, timeout); + b->I2CUDelay(b, b->HoldTime); + + b->I2CGetBits(b, &scl, psda); + + b->I2CPutBits(b, 0, 1); + b->I2CUDelay(b, b->HoldTime); + + return r; +} + +/* This is the default I2CPutByte function if not supplied by the driver. + * + * A single byte is sent to the device. + * The function returns FALSE if a timeout occurs, you should send + * a stop condition afterwards to reset the bus. + * + * A timeout occurs, + * if the slave pulls SCL to slow down the bus more than ByteTimeout usecs, + * or slows down the bus for more than BitTimeout usecs for each bit, + * or does not send an ACK bit (0) to acknowledge the transmission within + * AcknTimeout usecs, but a NACK (1) bit. + * + * AcknTimeout must be at least b->HoldTime, the other timeouts can be + * zero according to the comment on I2CRaiseSCL. + */ + +static Bool +I2CPutByte(I2CDevPtr d, I2CByte data) +{ + Bool r; + int i, scl, sda; + I2CBusPtr b = d->pI2CBus; + + if (!I2CWriteBit(b, (data >> 7) & 1, d->ByteTimeout)) + return FALSE; + + for (i = 6; i >= 0; i--) + if (!I2CWriteBit(b, (data >> i) & 1, d->BitTimeout)) + return FALSE; + + b->I2CPutBits(b, 0, 1); + b->I2CUDelay(b, b->RiseFallTime); + + r = I2CRaiseSCL(b, 1, b->HoldTime); + + if (r) { + for (i = d->AcknTimeout; i > 0; i -= b->HoldTime) { + b->I2CUDelay(b, b->HoldTime); + b->I2CGetBits(b, &scl, &sda); + if (sda == 0) break; + } + + if (i <= 0) { + I2C_TIMEOUT(ErrorF("[I2CPutByte(<%s>, 0x%02x, %d, %d, %d) timeout]", + b->BusName, data, d->BitTimeout, + d->ByteTimeout, d->AcknTimeout)); + r = FALSE; + } + + I2C_TRACE(ErrorF("W%02x%c ", (int) data, sda ? '-' : '+')); + } + + b->I2CPutBits(b, 0, 1); + b->I2CUDelay(b, b->HoldTime); + + return r; +} + +/* This is the default I2CGetByte function if not supplied by the driver. + * + * A single byte is read from the device. + * The function returns FALSE if a timeout occurs, you should send + * a stop condition afterwards to reset the bus. + * + * A timeout occurs, + * if the slave pulls SCL to slow down the bus more than ByteTimeout usecs, + * or slows down the bus for more than b->BitTimeout usecs for each bit. + * + * ByteTimeout must be at least b->HoldTime, the other timeouts can be + * zero according to the comment on I2CRaiseSCL. + * + * For the <last> byte in a sequence the acknowledge bit NACK (1), + * otherwise ACK (0) will be sent. + */ + +static Bool +I2CGetByte(I2CDevPtr d, I2CByte *data, Bool last) +{ + int i, sda; + I2CBusPtr b = d->pI2CBus; + + b->I2CPutBits(b, 0, 1); + b->I2CUDelay(b, b->RiseFallTime); + + if (!I2CReadBit(b, &sda, d->ByteTimeout)) + return FALSE; + + *data = (sda > 0) << 7; + + for (i = 6; i >= 0; i--) + if (!I2CReadBit(b, &sda, d->BitTimeout)) + return FALSE; + else + *data |= (sda > 0) << i; + + if (!I2CWriteBit(b, last ? 1 : 0, d->BitTimeout)) + return FALSE; + + I2C_TRACE(ErrorF("R%02x%c ", (int) *data, last ? '+' : '-')); + + return TRUE; +} + +/* This is the default I2CAddress function if not supplied by the driver. + * + * It creates the start condition, followed by the d->SlaveAddr. + * Higher level functions must call this routine rather than + * I2CStart/PutByte because a hardware I2C master may not be able + * to send a slave address without a start condition. + * + * The same timeouts apply as with I2CPutByte and additional a + * StartTimeout, similar to the ByteTimeout but for the start + * condition. + * + * In case of a timeout, the bus is left in a clean idle condition. + * I. e. you *must not* send a Stop. If this function succeeds, you *must*. + * + * The slave address format is 16 bit, with the legacy _8_bit_ slave address + * in the least significant byte. This is, the slave address must include the + * R/_W flag as least significant bit. + * + * The most significant byte of the address will be sent _after_ the LSB, + * but only if the LSB indicates: + * a) an 11 bit address, this is LSB = 1111 0xxx. + * b) a 'general call address', this is LSB = 0000 000x - see the I2C specs + * for more. + */ + +static Bool +I2CAddress(I2CDevPtr d, I2CSlaveAddr addr) +{ + if (I2CStart(d->pI2CBus, d->StartTimeout)) { + if (I2CPutByte(d, addr & 0xFF)) { + if ((addr & 0xF8) != 0xF0 && + (addr & 0xFE) != 0x00) + return TRUE; + + if (I2CPutByte(d, (addr >> 8) & 0xFF)) + return TRUE; + } + + I2CStop(d); + } + + return FALSE; +} + +/* These are the hardware independent I2C helper functions. + * ======================================================== + */ + +/* Function for probing. Just send the slave address + * and return true if the device responds. The slave address + * must have the lsb set to reflect a read (1) or write (0) access. + * Don't expect a read- or write-only device will respond otherwise. + */ + +Bool +xf86I2CProbeAddress(I2CBusPtr b, I2CSlaveAddr addr) +{ + int r; + I2CDevRec d; + + d.DevName = "Probing"; + d.BitTimeout = b->BitTimeout; + d.ByteTimeout = b->ByteTimeout; + d.AcknTimeout = b->AcknTimeout; + d.StartTimeout = b->StartTimeout; + d.SlaveAddr = addr; + d.pI2CBus = b; + d.NextDev = NULL; + + r = b->I2CAddress(&d, addr); + + if (r) b->I2CStop(&d); + + return r; +} + +/* All functions below are related to devices and take the + * slave address and timeout values from an I2CDevRec. They + * return FALSE in case of an error (presumably a timeout). + */ + +/* General purpose read and write function. + * + * 1st, if nWrite > 0 + * Send a start condition + * Send the slave address (1 or 2 bytes) with write flag + * Write n bytes from WriteBuffer + * 2nd, if nRead > 0 + * Send a start condition [again] + * Send the slave address (1 or 2 bytes) with read flag + * Read n bytes to ReadBuffer + * 3rd, if a Start condition has been successfully sent, + * Send a Stop condition. + * + * The functions exits immediately when an error occures, + * not proceeding any data left. However, step 3 will + * be executed anyway to leave the bus in clean idle state. + */ + +static Bool +I2CWriteRead(I2CDevPtr d, + I2CByte *WriteBuffer, int nWrite, + I2CByte *ReadBuffer, int nRead) +{ + Bool r = TRUE; + I2CBusPtr b = d->pI2CBus; + int s = 0; + + if (r && nWrite > 0) { + r = b->I2CAddress(d, d->SlaveAddr & ~1); + if (r) { + for (; nWrite > 0; WriteBuffer++, nWrite--) + if (!(r = b->I2CPutByte(d, *WriteBuffer))) + break; + s++; + } + } + + if (r && nRead > 0) { + r = b->I2CAddress(d, d->SlaveAddr | 1); + if (r) { + for (; nRead > 0; ReadBuffer++, nRead--) + if (!(r = b->I2CGetByte(d, ReadBuffer, nRead == 1))) + break; + s++; + } + } + + if (s) b->I2CStop(d); + + return r; +} + +/* wrapper - for compatibility and convinience */ + +Bool +xf86I2CWriteRead(I2CDevPtr d, + I2CByte *WriteBuffer, int nWrite, + I2CByte *ReadBuffer, int nRead) +{ + I2CBusPtr b = d->pI2CBus; + return b->I2CWriteRead(d,WriteBuffer,nWrite,ReadBuffer,nRead); +} + +/* Read a byte, the only readable register of a device. + */ + +Bool +xf86I2CReadStatus(I2CDevPtr d, I2CByte *pbyte) +{ + return xf86I2CWriteRead(d, NULL, 0, pbyte, 1); +} + +/* Read a byte from one of the registers determined by its sub-address. + */ + +Bool +xf86I2CReadByte(I2CDevPtr d, I2CByte subaddr, I2CByte *pbyte) +{ + return xf86I2CWriteRead(d, &subaddr, 1, pbyte, 1); +} + +/* Read bytes from subsequent registers determined by the + * sub-address of the first register. + */ + +Bool +xf86I2CReadBytes(I2CDevPtr d, I2CByte subaddr, I2CByte *pbyte, int n) +{ + return xf86I2CWriteRead(d, &subaddr, 1, pbyte, n); +} + +/* Read a word (high byte, then low byte) from one of the registers + * determined by its sub-address. + */ + +Bool +xf86I2CReadWord(I2CDevPtr d, I2CByte subaddr, unsigned short *pword) +{ + I2CByte rb[2]; + + if (!xf86I2CWriteRead(d, &subaddr, 1, rb, 2)) return FALSE; + + *pword = (rb[0] << 8) | rb[1]; + + return TRUE; +} + +/* Write a byte to one of the registers determined by its sub-address. + */ + +Bool +xf86I2CWriteByte(I2CDevPtr d, I2CByte subaddr, I2CByte byte) +{ + I2CByte wb[2]; + + wb[0] = subaddr; + wb[1] = byte; + + return xf86I2CWriteRead(d, wb, 2, NULL, 0); +} + +/* Write bytes to subsequent registers determined by the + * sub-address of the first register. + */ + +Bool +xf86I2CWriteBytes(I2CDevPtr d, I2CByte subaddr, + I2CByte *WriteBuffer, int nWrite) +{ + I2CBusPtr b = d->pI2CBus; + Bool r = TRUE; + + if (nWrite > 0) { + r = b->I2CAddress(d, d->SlaveAddr & ~1); + if (r){ + if ((r = b->I2CPutByte(d, subaddr))) + for (; nWrite > 0; WriteBuffer++, nWrite--) + if (!(r = b->I2CPutByte(d, *WriteBuffer))) + break; + + b->I2CStop(d); + } + } + + return r; +} + +/* Write a word (high byte, then low byte) to one of the registers + * determined by its sub-address. + */ + +Bool +xf86I2CWriteWord(I2CDevPtr d, I2CByte subaddr, unsigned short word) +{ + I2CByte wb[3]; + + wb[0] = subaddr; + wb[1] = word >> 8; + wb[2] = word & 0xFF; + + return xf86I2CWriteRead(d, wb, 3, NULL, 0); +} + +/* Write a vector of bytes to not adjacent registers. This vector is, + * 1st byte sub-address, 2nd byte value, 3rd byte sub-address asf. + * This function is intended to initialize devices. Note this function + * exits immediately when an error occurs, some registers may + * remain uninitialized. + */ + +Bool +xf86I2CWriteVec(I2CDevPtr d, I2CByte *vec, int nValues) +{ + I2CBusPtr b = d->pI2CBus; + Bool r = TRUE; + int s = 0; + + if (nValues > 0) { + for (; nValues > 0; nValues--, vec += 2) { + if (!(r = b->I2CAddress(d, d->SlaveAddr & ~1))) + break; + + s++; + + if (!(r = b->I2CPutByte(d, vec[0]))) + break; + + if (!(r = b->I2CPutByte(d, vec[1]))) + break; + } + + if (s > 0) b->I2CStop(d); + } + + return r; +} + +/* Administrative functions. + * ========================= + */ + +/* Allocates an I2CDevRec for you and initializes with propper defaults + * you may modify before calling xf86I2CDevInit. Your I2CDevRec must + * contain at least a SlaveAddr, and a pI2CBus pointer to the bus this + * device shall be linked to. + * + * See function I2CAddress for the slave address format. Always set + * the least significant bit, indicating a read or write access, to zero. + */ + +I2CDevPtr +xf86CreateI2CDevRec(void) +{ + return xcalloc(1, sizeof(I2CDevRec)); +} + +/* Unlink an I2C device. If you got the I2CDevRec from xf86CreateI2CDevRec + * you should set <unalloc> to free it. + */ + +void +xf86DestroyI2CDevRec(I2CDevPtr d, Bool unalloc) +{ + if (d) { + I2CDevPtr *p; + + /* Remove this from the list of active I2C devices. */ + + for (p = &d->pI2CBus->FirstDev; *p != NULL; p = &(*p)->NextDev) + if (*p == d) { + *p = (*p)->NextDev; + break; + } + + xf86DrvMsg(d->pI2CBus->scrnIndex, X_INFO, + "I2C device \"%s:%s\" removed.\n", + d->pI2CBus->BusName, d->DevName); + + if (unalloc) xfree(d); + } +} + +/* I2C transmissions are related to an I2CDevRec you must link to a + * previously registered bus (see xf86I2CBusInit) before attempting + * to read and write data. You may call xf86I2CProbeAddress first to + * see if the device in question is present on this bus. + * + * xf86I2CDevInit will not allocate an I2CBusRec for you, instead you + * may enter a pointer to a statically allocated I2CDevRec or the (modified) + * result of xf86CreateI2CDevRec. + * + * If you don't specify timeouts for the device (n <= 0), it will inherit + * the bus-wide defaults. The function returns TRUE on success. + */ + +Bool +xf86I2CDevInit(I2CDevPtr d) +{ + I2CBusPtr b; + + if (d == NULL || + (b = d->pI2CBus) == NULL || + (d->SlaveAddr & 1) || + xf86I2CFindDev(b, d->SlaveAddr) != NULL) + return FALSE; + + if (d->BitTimeout <= 0) d->BitTimeout = b->BitTimeout; + if (d->ByteTimeout <= 0) d->ByteTimeout = b->ByteTimeout; + if (d->AcknTimeout <= 0) d->AcknTimeout = b->AcknTimeout; + if (d->StartTimeout <= 0) d->StartTimeout = b->StartTimeout; + + d->NextDev = b->FirstDev; + b->FirstDev = d; + + xf86DrvMsg(b->scrnIndex, X_INFO, + "I2C device \"%s:%s\" registered at address 0x%02X.\n", + b->BusName, d->DevName, d->SlaveAddr); + + return TRUE; +} + +I2CDevPtr +xf86I2CFindDev(I2CBusPtr b, I2CSlaveAddr addr) +{ + I2CDevPtr d; + + if (b) { + for (d = b->FirstDev; d != NULL; d = d->NextDev) + if (d->SlaveAddr == addr) + return d; + } + + return NULL; +} + +static I2CBusPtr I2CBusList; + +/* Allocates an I2CBusRec for you and initializes with propper defaults + * you may modify before calling xf86I2CBusInit. Your I2CBusRec must + * contain at least a BusName, a scrnIndex (or -1), and a complete set + * of either high or low level I2C function pointers. You may pass + * bus-wide timeouts, otherwise inplausible values will be replaced + * with safe defaults. + */ + +I2CBusPtr +xf86CreateI2CBusRec(void) +{ + I2CBusPtr b; + + b = (I2CBusPtr) xcalloc(1, sizeof(I2CBusRec)); + + if (b != NULL) { + b->scrnIndex = -1; + b->HoldTime = 5; /* 100 kHz bus */ + b->BitTimeout = 5; + b->ByteTimeout = 5; + b->AcknTimeout = 5; + b->StartTimeout = 5; + b->RiseFallTime = RISEFALLTIME; + } + + return b; +} + +/* Unregister an I2C bus. If you got the I2CBusRec from xf86CreateI2CBusRec + * you should set <unalloc> to free it. If you set <devs_too>, the function + * xf86DestroyI2CDevRec will be called for all devices linked to the bus + * first, passing down the <unalloc> option. + */ + +void +xf86DestroyI2CBusRec(I2CBusPtr b, Bool unalloc, Bool devs_too) +{ + if (b) { + I2CBusPtr *p; + + /* Remove this from the list of active I2C busses. */ + + for (p = &I2CBusList; *p != NULL; p = &(*p)->NextBus) + if (*p == b) { + *p = (*p)->NextBus; + break; + } + + if (b->FirstDev != NULL) { + if (devs_too) { + I2CDevPtr d; + + while ((d = b->FirstDev) != NULL) { + b->FirstDev = d->NextDev; + xf86DestroyI2CDevRec(d, unalloc); + } + } else { + if (unalloc) { + xf86Msg(X_ERROR, "i2c bug: Attempt to remove I2C bus \"%s\", " + "but device list is not empty.\n", + b->BusName); + return; + } + } + } + + xf86DrvMsg(b->scrnIndex, X_INFO, "I2C bus \"%s\" removed.\n", + b->BusName); + + if (unalloc) xfree(b); + } +} + +/* I2C masters have to register themselves using this function. + * It will not allocate an I2CBusRec for you, instead you may enter + * a pointer to a statically allocated I2CBusRec or the (modified) + * result of xf86CreateI2CBusRec. Returns TRUE on success. + * + * At this point there won't be any traffic on the I2C bus. + */ + +Bool +xf86I2CBusInit(I2CBusPtr b) +{ + /* I2C busses must be identified by a unique scrnIndex + * and name. If scrnIndex is unspecified (a negative value), + * then the name must be unique throughout the server. + */ + + if (b->BusName == NULL || + xf86I2CFindBus(b->scrnIndex, b->BusName) != NULL) + return FALSE; + + /* If the high level functions are not + * supplied, use the generic functions. + * In this case we need the low-level + * function. + */ + if (b->I2CWriteRead == NULL) + { + b->I2CWriteRead=I2CWriteRead; + + if (b->I2CPutBits == NULL || + b->I2CGetBits == NULL) + { + if (b->I2CPutByte == NULL || + b->I2CGetByte == NULL || + b->I2CAddress == NULL || + b->I2CStop == NULL) + return FALSE; + } else { + b->I2CPutByte = I2CPutByte; + b->I2CGetByte = I2CGetByte; + b->I2CAddress = I2CAddress; + b->I2CStop = I2CStop; + } + } + + if (b->I2CUDelay == NULL) + b->I2CUDelay = I2CUDelay; + + if (b->HoldTime < 2) b->HoldTime = 5; + if (b->BitTimeout <= 0) b->BitTimeout = b->HoldTime; + if (b->ByteTimeout <= 0) b->ByteTimeout = b->HoldTime; + if (b->AcknTimeout <= 0) b->AcknTimeout = b->HoldTime; + if (b->StartTimeout <= 0) b->StartTimeout = b->HoldTime; + + /* Put new bus on list. */ + + b->NextBus = I2CBusList; + I2CBusList = b; + + xf86DrvMsg(b->scrnIndex, X_INFO, "I2C bus \"%s\" initialized.\n", + b->BusName); + + return TRUE; +} + +I2CBusPtr +xf86I2CFindBus(int scrnIndex, char *name) +{ + I2CBusPtr p; + + if (name != NULL) + for (p = I2CBusList; p != NULL; p = p->NextBus) + if (scrnIndex < 0 || p->scrnIndex == scrnIndex) + if (!strcmp(p->BusName, name)) + return p; + + return NULL; +} |