diff options
Diffstat (limited to 'src/mainboard/intel/wtm2/intel_dp.c')
| -rw-r--r-- | src/mainboard/intel/wtm2/intel_dp.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/src/mainboard/intel/wtm2/intel_dp.c b/src/mainboard/intel/wtm2/intel_dp.c new file mode 100644 index 0000000000..b864313f31 --- /dev/null +++ b/src/mainboard/intel/wtm2/intel_dp.c @@ -0,0 +1,168 @@ +/* + * 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; +} + |