diff options
Diffstat (limited to 'sys/dev/i2c/i2c_exec.c')
| -rw-r--r-- | sys/dev/i2c/i2c_exec.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/sys/dev/i2c/i2c_exec.c b/sys/dev/i2c/i2c_exec.c new file mode 100644 index 00000000000..f76d17cf949 --- /dev/null +++ b/sys/dev/i2c/i2c_exec.c @@ -0,0 +1,157 @@ +/* $OpenBSD: i2c_exec.c,v 1.1 2004/05/23 17:33:43 grange Exp $ */ +/* $NetBSD: i2c_exec.c,v 1.3 2003/10/29 00:34:58 mycroft Exp $ */ + +/* + * Copyright (c) 2003 Wasabi Systems, Inc. + * All rights reserved. + * + * Written by Jason R. Thorpe for Wasabi Systems, Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed for the NetBSD Project by + * Wasabi Systems, Inc. + * 4. The name of Wasabi Systems, Inc. may not be used to endorse + * or promote products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/device.h> +#include <sys/event.h> +#include <sys/conf.h> + +#define _I2C_PRIVATE +#include <dev/i2c/i2cvar.h> + +/* + * iic_exec: + * + * Simplified I2C client interface engine. + * + * This and the SMBus routines are the preferred interface for + * client access to I2C/SMBus, since many automated controllers + * do not provide access to the low-level primitives of the I2C + * bus protocol. + */ +int +iic_exec(i2c_tag_t tag, i2c_op_t op, i2c_addr_t addr, const void *vcmd, + size_t cmdlen, void *vbuf, size_t buflen, int flags) +{ + const uint8_t *cmd = vcmd; + uint8_t *buf = vbuf; + int error; + size_t len; + + /* + * Defer to the controller if it provides an exec function. Use + * it if it does. + */ + if (tag->ic_exec != NULL) + return ((*tag->ic_exec)(tag->ic_cookie, op, addr, cmd, + cmdlen, buf, buflen, flags)); + + if ((len = cmdlen) != 0) { + if ((error = iic_initiate_xfer(tag, addr, flags)) != 0) + goto bad; + while (len--) { + if ((error = iic_write_byte(tag, *cmd++, flags)) != 0) + goto bad; + } + } + + if (I2C_OP_READ_P(op)) + flags |= I2C_F_READ; + + len = buflen; + while (len--) { + if (len == 0 && I2C_OP_STOP_P(op)) + flags |= I2C_F_STOP; + if (I2C_OP_READ_P(op)) { + /* Send REPEATED START. */ + if ((len + 1) == buflen && + (error = iic_initiate_xfer(tag, addr, flags)) != 0) + goto bad; + /* NACK on last byte. */ + if (len == 0) + flags |= I2C_F_LAST; + if ((error = iic_read_byte(tag, buf++, flags)) != 0) + goto bad; + } else { + /* Maybe send START. */ + if ((len + 1) == buflen && cmdlen == 0 && + (error = iic_initiate_xfer(tag, addr, flags)) != 0) + goto bad; + if ((error = iic_write_byte(tag, *buf++, flags)) != 0) + goto bad; + } + } + + return (0); + bad: + iic_send_stop(tag, flags); + return (error); +} + +/* + * iic_smbus_write_byte: + * + * Perform an SMBus "write byte" operation. + */ +int +iic_smbus_write_byte(i2c_tag_t tag, i2c_addr_t addr, uint8_t cmd, + uint8_t val, int flags) +{ + + return (iic_exec(tag, I2C_OP_WRITE_WITH_STOP, addr, &cmd, 1, + &val, 1, flags)); +} + +/* + * iic_smbus_read_byte: + * + * Perform an SMBus "read byte" operation. + */ +int +iic_smbus_read_byte(i2c_tag_t tag, i2c_addr_t addr, uint8_t cmd, + uint8_t *valp, int flags) +{ + + return (iic_exec(tag, I2C_OP_READ_WITH_STOP, addr, &cmd, 1, + valp, 1, flags)); +} + +/* + * iic_smbus_receive_byte: + * + * Perform an SMBus "receive byte" operation. + */ +int +iic_smbus_receive_byte(i2c_tag_t tag, i2c_addr_t addr, uint8_t *valp, + int flags) +{ + + return (iic_exec(tag, I2C_OP_READ_WITH_STOP, addr, NULL, 0, + valp, 1, flags)); +} |