diff options
Diffstat (limited to 'src/drivers/intel/gma/drm_dp_helper.c')
| -rw-r--r-- | src/drivers/intel/gma/drm_dp_helper.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/src/drivers/intel/gma/drm_dp_helper.c b/src/drivers/intel/gma/drm_dp_helper.c new file mode 100644 index 0000000000..66072263f4 --- /dev/null +++ b/src/drivers/intel/gma/drm_dp_helper.c @@ -0,0 +1,119 @@ +/* + * Copyright 2013 Google Inc. + * 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 <console/console.h> +#include <stdint.h> +#include <delay.h> +#include <drivers/intel/gma/i915.h> +#include <string.h> + +#include <edid.h> + +/* reduced a lot for coreboot. */ +/** + * DOC: dp helpers + * + * These functions contain some common logic and helpers at various + * abstraction levels to deal with Display Port sink devices and + * related things like DP aux channel transfers, EDID reading over DP + * aux channels, decoding certain DPCD blocks, ... + */ + + +/* Helpers for DP link training */ +static u8 dp_link_status(u8 link_status[DP_LINK_STATUS_SIZE], int r) +{ + printk(BIOS_SPEW, "%s: %d, %d, %d\n", __func__, + r, r - DP_LANE0_1_STATUS, + link_status[r - DP_LANE0_1_STATUS]); + return link_status[r - DP_LANE0_1_STATUS]; +} + +static u8 dp_get_lane_status(u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_LANE0_1_STATUS + (lane >> 1); + int s = (lane & 1) * 4; + u8 l = dp_link_status(link_status, i); + return (l >> s) & 0xf; +} + +int drm_dp_channel_eq_ok(u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + u8 lane_align; + u8 lane_status; + int lane; + + lane_align = dp_link_status(link_status, + DP_LANE_ALIGN_STATUS_UPDATED); + if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0) + return 0; + for (lane = 0; lane < lane_count; lane++) { + lane_status = dp_get_lane_status(link_status, lane); + if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS) + return 0; + } + return 1; +} + +int drm_dp_clock_recovery_ok(u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + int lane; + u8 lane_status; + + for (lane = 0; lane < lane_count; lane++) { + lane_status = dp_get_lane_status(link_status, lane); + if ((lane_status & DP_LANE_CR_DONE) == 0) + return 0; + } + return 1; +} + +u8 drm_dp_get_adjust_request_voltage(u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); + int s = ((lane & 1) ? + DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT : + DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT); + u8 l = dp_link_status(link_status, i); + + printk(BIOS_SPEW, "%s: i %d s %d l %d return %d\n", + __func__, i, s, l, + ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT); + return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT; +} + +u8 drm_dp_get_adjust_request_pre_emphasis(u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); + int s = ((lane & 1) ? + DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT : + DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT); + u8 l = dp_link_status(link_status, i); + + return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT; +} |