freebsd-dev/sys/dev/drm2/drm_dp_iic_helper.c
Warner Losh 592ffb2175 Revert drm2 removal.
Revert r338177, r338176, r338175, r338174, r338172

After long consultations with re@, core members and mmacy, revert
these changes. Followup changes will be made to mark them as
deprecated and prent a message about where to find the up-to-date
driver.  Followup commits will be made to make this clear in the
installer. Followup commits to reduce POLA in ways we're still
exploring.

It's anticipated that after the freeze, this will be removed in
13-current (with the residual of the drm2 code copied to
sys/arm/dev/drm2 for the TEGRA port's use w/o the intel or
radeon drivers).

Due to the impending freeze, there was no formal core vote for
this. I've been talking to different core members all day, as well as
Matt Macey and Glen Barber. Nobody is completely happy, all are
grudgingly going along with this. Work is in progress to mitigate
the negative effects as much as possible.

Requested by: re@ (gjb, rgrimes)
2018-08-24 00:02:00 +00:00

279 lines
6.5 KiB
C

/*
* 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);