freebsd-dev/sys/dev/iicbus/iicoc.c
Philip Paeps eb95689a82 iicoc: split up common core and PCI bus specifics
The OpenCores I2C IP core can be found on any bus.  Split out the PCI
bus specifics into their own file, only compiled on systems with PCI.

Reviewed by:    kp
Sponsored by:   Axiado
2019-12-20 03:40:46 +00:00

278 lines
6.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2003-2012 Broadcom Corporation
* All Rights Reserved
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY BROADCOM ``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 BROADCOM OR CONTRIBUTORS 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/rman.h>
#include <machine/bus.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#include "iicbus_if.h"
#include "iicoc.h"
devclass_t iicoc_devclass;
DRIVER_MODULE(iicbus, iicoc, iicbus_driver, iicbus_devclass, 0, 0);
static void
iicoc_dev_write(device_t dev, int reg, int value)
{
struct iicoc_softc *sc;
sc = device_get_softc(dev);
bus_write_1(sc->mem_res, reg<<sc->reg_shift, value);
}
static int
iicoc_dev_read(device_t dev, int reg)
{
uint8_t val;
struct iicoc_softc *sc;
sc = device_get_softc(dev);
val = bus_read_1(sc->mem_res, reg<<sc->reg_shift);
return (val);
}
static int
iicoc_wait_on_status(device_t dev, uint8_t bit)
{
int tries = I2C_TIMEOUT;
uint8_t status;
do {
status = iicoc_dev_read(dev, OC_I2C_STATUS_REG);
} while ((status & bit) != 0 && --tries > 0);
return (tries == 0 ? -1: 0);
}
static int
iicoc_rd_cmd(device_t dev, uint8_t cmd)
{
uint8_t data;
iicoc_dev_write(dev, OC_I2C_CMD_REG, cmd);
if (iicoc_wait_on_status(dev, OC_STATUS_TIP) < 0) {
device_printf(dev, "read: Timeout waiting for TIP clear.\n");
return (-1);
}
data = iicoc_dev_read(dev, OC_I2C_DATA_REG);
return (data);
}
static int
iicoc_wr_cmd(device_t dev, uint8_t data, uint8_t cmd)
{
iicoc_dev_write(dev, OC_I2C_DATA_REG, data);
iicoc_dev_write(dev, OC_I2C_CMD_REG, cmd);
if (iicoc_wait_on_status(dev, OC_STATUS_TIP) < 0) {
device_printf(dev, "write: Timeout waiting for TIP clear.\n");
return (-1);
}
return (0);
}
static int
iicoc_wr_ack_cmd(device_t dev, uint8_t data, uint8_t cmd)
{
if (iicoc_wr_cmd(dev, data, cmd) < 0)
return (-1);
if (iicoc_dev_read(dev, OC_I2C_STATUS_REG) & OC_STATUS_NACK) {
device_printf(dev, "write: I2C command ACK Error.\n");
return (IIC_ENOACK);
}
return (0);
}
int
iicoc_init(device_t dev)
{
struct iicoc_softc *sc;
int value;
sc = device_get_softc(dev);
value = iicoc_dev_read(dev, OC_I2C_CTRL_REG);
iicoc_dev_write(dev, OC_I2C_CTRL_REG,
value & ~(OC_CONTROL_EN | OC_CONTROL_IEN));
value = (sc->clockfreq/(5 * sc->i2cfreq)) - 1;
iicoc_dev_write(dev, OC_I2C_PRESCALE_LO_REG, value & 0xff);
iicoc_dev_write(dev, OC_I2C_PRESCALE_HI_REG, value >> 8);
value = iicoc_dev_read(dev, OC_I2C_CTRL_REG);
iicoc_dev_write(dev, OC_I2C_CTRL_REG, value | OC_CONTROL_EN);
value = iicoc_dev_read(dev, OC_I2C_CTRL_REG);
/* return 0 on success, 1 on error */
return ((value & OC_CONTROL_EN) == 0);
}
int
iicoc_iicbus_start(device_t dev, u_char slave, int timeout)
{
int error = IIC_EBUSERR;
struct iicoc_softc *sc;
sc = device_get_softc(dev);
mtx_lock(&sc->sc_mtx);
sc->i2cdev_addr = (slave >> 1);
/* Verify the bus is idle */
if (iicoc_wait_on_status(dev, OC_STATUS_BUSY) < 0)
goto i2c_stx_error;
/* Write Slave Address */
if (iicoc_wr_ack_cmd(dev, slave, OC_COMMAND_START)) {
device_printf(dev,
"I2C write slave address [0x%x] failed.\n", slave);
error = IIC_ENOACK;
goto i2c_stx_error;
}
/* Verify Arbitration is not Lost */
if (iicoc_dev_read(dev, OC_I2C_STATUS_REG) & OC_STATUS_AL) {
device_printf(dev, "I2C Bus Arbitration Lost, Aborting.\n");
error = IIC_EBUSERR;
goto i2c_stx_error;
}
error = IIC_NOERR;
mtx_unlock(&sc->sc_mtx);
return (error);
i2c_stx_error:
iicoc_dev_write(dev, OC_I2C_CMD_REG, OC_COMMAND_STOP);
iicoc_wait_on_status(dev, OC_STATUS_BUSY); /* wait for idle */
mtx_unlock(&sc->sc_mtx);
return (error);
}
int
iicoc_iicbus_stop(device_t dev)
{
int error = 0;
struct iicoc_softc *sc;
sc = device_get_softc(dev);
mtx_lock(&sc->sc_mtx);
iicoc_dev_write(dev, OC_I2C_CMD_REG, OC_COMMAND_STOP);
iicoc_wait_on_status(dev, OC_STATUS_BUSY); /* wait for idle */
mtx_unlock(&sc->sc_mtx);
return (error);
}
int
iicoc_iicbus_write(device_t dev, const char *buf, int len, int *sent,
int timeout)
{
uint8_t value;
int i;
value = buf[0];
/* Write Slave Offset */
if (iicoc_wr_ack_cmd(dev, value, OC_COMMAND_WRITE)) {
device_printf(dev, "I2C write slave offset failed.\n");
goto i2c_tx_error;
}
for (i = 1; i < len; i++) {
/* Write data byte */
value = buf[i];
if (iicoc_wr_cmd(dev, value, OC_COMMAND_WRITE)) {
device_printf(dev, "I2C write data byte %d failed.\n",
i);
goto i2c_tx_error;
}
}
*sent = len;
return (IIC_NOERR);
i2c_tx_error:
return (IIC_EBUSERR);
}
int
iicoc_iicbus_read(device_t dev, char *buf, int len, int *read, int last,
int delay)
{
int data, i;
uint8_t cmd;
for (i = 0; i < len; i++) {
/* Read data byte */
cmd = (i == len - 1) ? OC_COMMAND_RDNACK : OC_COMMAND_READ;
data = iicoc_rd_cmd(dev, cmd);
if (data < 0) {
device_printf(dev,
"I2C read data byte %d failed.\n", i);
goto i2c_rx_error;
}
buf[i] = (uint8_t)data;
}
*read = len;
return (IIC_NOERR);
i2c_rx_error:
return (IIC_EBUSERR);
}
int
iicoc_iicbus_reset(device_t dev, u_char speed, u_char addr, u_char *oldadr)
{
int error;
struct iicoc_softc *sc;
sc = device_get_softc(dev);
mtx_lock(&sc->sc_mtx);
error = iicoc_init(dev);
mtx_unlock(&sc->sc_mtx);
return (error);
}
int
iicoc_iicbus_repeated_start(device_t dev, u_char slave, int timeout)
{
return 0;
}