/*
* Copyright © 2009 Keith Packard
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/kobj.h>
#include <sys/bus.h>
#include <dev/iicbus/iic.h>
#include "iicbus_if.h"
#include <dev/iicbus/iiconf.h>
#include <dev/drm2/drmP.h>
#include <dev/drm2/drm_dp_helper.h>
static int
iic_dp_aux_transaction(device_t idev, int mode, uint8_t write_byte,
uint8_t *read_byte)
{
struct iic_dp_aux_data *aux_data;
int ret;
aux_data = device_get_softc(idev);
ret = (*aux_data->aux_ch)(idev, mode, write_byte, read_byte);
if (ret < 0)
return (ret);
return (0);
}
/*
* I2C over AUX CH
*/
/*
* Send the address. If the I2C link is running, this 'restarts'
* the connection with the new address, this is used for doing
* a write followed by a read (as needed for DDC)
*/
static int
iic_dp_aux_address(device_t idev, u16 address, bool reading)
{
struct iic_dp_aux_data *aux_data;
int mode, ret;
aux_data = device_get_softc(idev);
mode = MODE_I2C_START;
if (reading)
mode |= MODE_I2C_READ;
else
mode |= MODE_I2C_WRITE;
aux_data->address = address;
aux_data->running = true;
ret = iic_dp_aux_transaction(idev, mode, 0, NULL);
return (ret);
}
/*
* Stop the I2C transaction. This closes out the link, sending
* a bare address packet with the MOT bit turned off
*/
static void
iic_dp_aux_stop(device_t idev, bool reading)
{
struct iic_dp_aux_data *aux_data;
int mode;
aux_data = device_get_softc(idev);
mode = MODE_I2C_STOP;
if (reading)
mode |= MODE_I2C_READ;
else
mode |= MODE_I2C_WRITE;
if (aux_data->running) {
(void)iic_dp_aux_transaction(idev, mode, 0, NULL);
aux_data->running = false;
}
}
/*
* Write a single byte to the current I2C address, the
* the I2C link must be running or this returns -EIO
*/
static int
iic_dp_aux_put_byte(device_t idev, u8 byte)
{
struct iic_dp_aux_data *aux_data;
int ret;
aux_data = device_get_softc(idev);
if (!aux_data->running)
return (-EIO);
ret = iic_dp_aux_transaction(idev, MODE_I2C_WRITE, byte, NULL);
return (ret);
}
/*
* Read a single byte from the current I2C address, the
* I2C link must be running or this returns -EIO
*/
static int
iic_dp_aux_get_byte(device_t idev, u8 *byte_ret)
{
struct iic_dp_aux_data *aux_data;
int ret;
aux_data = device_get_softc(idev);
if (!aux_data->running)
return (-EIO);
ret = iic_dp_aux_transaction(idev, MODE_I2C_READ, 0, byte_ret);
return (ret);
}
static int
iic_dp_aux_xfer(device_t idev, struct iic_msg *msgs, uint32_t num)
{
u8 *buf;
int b, m, ret;
u16 len;
bool reading;
ret = 0;
reading = false;
for (m = 0; m < num; m++) {
len = msgs[m].len;
buf = msgs[m].buf;
reading = (msgs[m].flags & IIC_M_RD) != 0;
ret = iic_dp_aux_address(idev, msgs[m].slave >> 1, reading);
if (ret < 0)
break;
if (reading) {
for (b = 0; b < len; b++) {
ret = iic_dp_aux_get_byte(idev, &buf[b]);
if (ret != 0)
break;
}
} else {
for (b = 0; b < len; b++) {
ret = iic_dp_aux_put_byte(idev, buf[b]);
if (ret < 0)
break;
}
}
if (ret != 0)
break;
}
iic_dp_aux_stop(idev, reading);
DRM_DEBUG_KMS("dp_aux_xfer return %d\n", ret);
return (-ret);
}
static void
iic_dp_aux_reset_bus(device_t idev)
{
(void)iic_dp_aux_address(idev, 0, false);
(void)iic_dp_aux_stop(idev, false);
}
static int
iic_dp_aux_reset(device_t idev, u_char speed, u_char addr, u_char *oldaddr)
{
iic_dp_aux_reset_bus(idev);
return (0);
}
static int
iic_dp_aux_prepare_bus(device_t idev)
{
/* adapter->retries = 3; */
iic_dp_aux_reset_bus(idev);
return (0);
}
static int
iic_dp_aux_probe(device_t idev)
{
return (BUS_PROBE_DEFAULT);
}
static int
iic_dp_aux_attach(device_t idev)
{
struct iic_dp_aux_data *aux_data;
aux_data = device_get_softc(idev);
aux_data->port = device_add_child(idev, "iicbus", -1);
if (aux_data->port == NULL)
return (ENXIO);
device_quiet(aux_data->port);
bus_generic_attach(idev);
return (0);
}
int
iic_dp_aux_add_bus(device_t dev, const char *name,
int (*ch)(device_t idev, int mode, uint8_t write_byte, uint8_t *read_byte),
void *priv, device_t *bus, device_t *adapter)
{
device_t ibus;
struct iic_dp_aux_data *data;
int idx, error;
static int dp_bus_counter;
mtx_lock(&Giant);
idx = atomic_fetchadd_int(&dp_bus_counter, 1);
ibus = device_add_child(dev, "drm_iic_dp_aux", idx);
if (ibus == NULL) {
mtx_unlock(&Giant);
DRM_ERROR("drm_iic_dp_aux bus %d creation error\n", idx);
return (-ENXIO);
}
device_quiet(ibus);
error = device_probe_and_attach(ibus);
if (error != 0) {
device_delete_child(dev, ibus);
mtx_unlock(&Giant);
DRM_ERROR("drm_iic_dp_aux bus %d attach failed, %d\n",
idx, error);
return (-error);
}
data = device_get_softc(ibus);
data->running = false;
data->address = 0;
data->aux_ch = ch;
data->priv = priv;
error = iic_dp_aux_prepare_bus(ibus);
if (error == 0) {
*bus = ibus;
*adapter = data->port;
}
mtx_unlock(&Giant);
return (-error);
}
static device_method_t drm_iic_dp_aux_methods[] = {
DEVMETHOD(device_probe, iic_dp_aux_probe),
DEVMETHOD(device_attach, iic_dp_aux_attach),
DEVMETHOD(device_detach, bus_generic_detach),
DEVMETHOD(iicbus_reset, iic_dp_aux_reset),
DEVMETHOD(iicbus_transfer, iic_dp_aux_xfer),
DEVMETHOD_END
};
static driver_t drm_iic_dp_aux_driver = {
"drm_iic_dp_aux",
drm_iic_dp_aux_methods,
sizeof(struct iic_dp_aux_data)
};
static devclass_t drm_iic_dp_aux_devclass;
DRIVER_MODULE_ORDERED(drm_iic_dp_aux, drmn, drm_iic_dp_aux_driver,
drm_iic_dp_aux_devclass, 0, 0, SI_ORDER_SECOND);
