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/*
* Copyright 2013 Google Inc.
* Copyright © 2008 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Keith Packard <keithp@keithp.com>
*
*/
#include <console/console.h>
#include <stdint.h>
#include <delay.h>
#include "i915io.h"
u32
pack_aux(u32 *src32, int src_bytes)
{
u8 *src = (u8 *)src32;
int i;
u32 v = 0;
if (src_bytes > 4)
src_bytes = 4;
for (i = 0; i < src_bytes; i++)
v |= ((u32) src[i]) << ((3-i) * 8);
return v;
}
void
unpack_aux(u32 src, u32 *dst32, int dst_bytes)
{
u8 *dst = (u8 *)dst32;
int i;
if (dst_bytes > 4)
dst_bytes = 4;
for (i = 0; i < dst_bytes; i++)
dst[i] = src >> ((3-i) * 8);
}
int
intel_dp_aux_ch(u32 ch_ctl, u32 ch_data, u32 *send, int send_bytes,
u32 *recv, int recv_size)
{
int i;
int recv_bytes;
u32 status;
u32 aux_clock_divider;
int try, precharge = 5;
/* The clock divider is based off the hrawclk,
* and would like to run at 2MHz. So, take the
* hrawclk value and divide by 2 and use that
*
* Note that PCH attached eDP panels should use a 125MHz input
* clock divider.
*/
/* 200 on link */
aux_clock_divider = 200; /* SNB & IVB eDP input clock at 400Mhz */
/* Try to wait for any previous AUX channel activity */
for (try = 0; try < 3; try++) {
status = io_i915_READ32(ch_ctl);
if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
break;
udelay(1000);
}
if (try == 3) {
printk(BIOS_SPEW, "[000000.0] [drm:%s], ", __func__);
printk(BIOS_SPEW, "dp_aux_ch not started status 0x%08lx\n",
io_i915_READ32(ch_ctl));
return -1;
}
/* Must try at least 3 times according to DP spec */
for (try = 0; try < 5; try++) {
/* Load the send data into the aux channel data registers */
for (i = 0; i < send_bytes; i += 4)
io_i915_WRITE32(send[i], ch_data + i);
/* Send the command and wait for it to complete */
io_i915_WRITE32(
DP_AUX_CH_CTL_SEND_BUSY |
DP_AUX_CH_CTL_TIME_OUT_400us |
(send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
(precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
(aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT) |
DP_AUX_CH_CTL_DONE |
DP_AUX_CH_CTL_TIME_OUT_ERROR |
DP_AUX_CH_CTL_RECEIVE_ERROR, ch_ctl);
for (;;) {
status = io_i915_READ32(ch_ctl);
if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
break;
udelay(100);
}
/* Clear done status and any errors */
io_i915_WRITE32(
status |
DP_AUX_CH_CTL_DONE |
DP_AUX_CH_CTL_TIME_OUT_ERROR |
DP_AUX_CH_CTL_RECEIVE_ERROR, ch_ctl);
if (status & (DP_AUX_CH_CTL_TIME_OUT_ERROR |
DP_AUX_CH_CTL_RECEIVE_ERROR))
continue;
if (status & DP_AUX_CH_CTL_DONE)
break;
}
if ((status & DP_AUX_CH_CTL_DONE) == 0) {
printk(BIOS_SPEW, "[000000.0] [drm:%s], ", __func__);
printk(BIOS_SPEW, "dp_aux_ch not done status 0x%08x\n", status);
return -1;
}
/* Check for timeout or receive error.
* Timeouts occur when the sink is not connected
*/
if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
printk(BIOS_SPEW, "[000000.0] [drm:%s], ", __func__);
printk(BIOS_SPEW,
"dp_aux_ch receive error status 0x%08x\n", status);
return -1;
}
/* Timeouts occur when the device isn't connected, so they're
* "normal" -- don't fill the kernel log with these */
if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR) {
printk(BIOS_SPEW, "[000000.0] [drm:%s], ", __func__);
printk(BIOS_SPEW, "dp_aux_ch timeout status 0x%08x\n", status);
return -1;
}
/* Unload any bytes sent back from the other side */
recv_bytes = ((status & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >>
DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT);
if (recv_bytes > recv_size)
recv_bytes = recv_size;
for (i = 0; i < recv_bytes; i += 4)
unpack_aux(io_i915_READ32(ch_data + i),
recv + i, recv_bytes - i);
return recv_bytes;
}
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