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author | Jakub Kicinski <kuba@kernel.org> | 2024-03-22 02:14:13 +0300 |
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committer | Jakub Kicinski <kuba@kernel.org> | 2024-03-22 02:15:08 +0300 |
commit | 537c2e91d3549e5d6020bb0576cf9b54a845255f (patch) | |
tree | c09e8a1b7d733cde19b0c72678c28fb2bc97ff6b /drivers/gpu/drm/msm/dp/dp_utils.c | |
parent | 237bb5f7f7f55ec5f773469a974c61a49c298625 (diff) | |
parent | cba9ffdb9913dfe6be29f049ce920ce451ce7cc4 (diff) | |
download | linux-537c2e91d3549e5d6020bb0576cf9b54a845255f.tar.xz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/gpu/drm/msm/dp/dp_utils.c')
-rw-r--r-- | drivers/gpu/drm/msm/dp/dp_utils.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/dp/dp_utils.c b/drivers/gpu/drm/msm/dp/dp_utils.c new file mode 100644 index 000000000000..da9207caf72d --- /dev/null +++ b/drivers/gpu/drm/msm/dp/dp_utils.c @@ -0,0 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2024, The Linux Foundation. All rights reserved. + */ + +#include <linux/types.h> + +#include "dp_utils.h" + +#define DP_SDP_HEADER_SIZE 8 + +u8 dp_utils_get_g0_value(u8 data) +{ + u8 c[4]; + u8 g[4]; + u8 ret_data = 0; + u8 i; + + for (i = 0; i < 4; i++) + c[i] = (data >> i) & 0x01; + + g[0] = c[3]; + g[1] = c[0] ^ c[3]; + g[2] = c[1]; + g[3] = c[2]; + + for (i = 0; i < 4; i++) + ret_data = ((g[i] & 0x01) << i) | ret_data; + + return ret_data; +} + +u8 dp_utils_get_g1_value(u8 data) +{ + u8 c[4]; + u8 g[4]; + u8 ret_data = 0; + u8 i; + + for (i = 0; i < 4; i++) + c[i] = (data >> i) & 0x01; + + g[0] = c[0] ^ c[3]; + g[1] = c[0] ^ c[1] ^ c[3]; + g[2] = c[1] ^ c[2]; + g[3] = c[2] ^ c[3]; + + for (i = 0; i < 4; i++) + ret_data = ((g[i] & 0x01) << i) | ret_data; + + return ret_data; +} + +u8 dp_utils_calculate_parity(u32 data) +{ + u8 x0 = 0; + u8 x1 = 0; + u8 ci = 0; + u8 iData = 0; + u8 i = 0; + u8 parity_byte; + u8 num_byte = (data & 0xFF00) > 0 ? 8 : 2; + + for (i = 0; i < num_byte; i++) { + iData = (data >> i * 4) & 0xF; + + ci = iData ^ x1; + x1 = x0 ^ dp_utils_get_g1_value(ci); + x0 = dp_utils_get_g0_value(ci); + } + + parity_byte = x1 | (x0 << 4); + + return parity_byte; +} + +ssize_t dp_utils_pack_sdp_header(struct dp_sdp_header *sdp_header, u32 *header_buff) +{ + size_t length; + + length = sizeof(header_buff); + if (length < DP_SDP_HEADER_SIZE) + return -ENOSPC; + + header_buff[0] = FIELD_PREP(HEADER_0_MASK, sdp_header->HB0) | + FIELD_PREP(PARITY_0_MASK, dp_utils_calculate_parity(sdp_header->HB0)) | + FIELD_PREP(HEADER_1_MASK, sdp_header->HB1) | + FIELD_PREP(PARITY_1_MASK, dp_utils_calculate_parity(sdp_header->HB1)); + + header_buff[1] = FIELD_PREP(HEADER_2_MASK, sdp_header->HB2) | + FIELD_PREP(PARITY_2_MASK, dp_utils_calculate_parity(sdp_header->HB2)) | + FIELD_PREP(HEADER_3_MASK, sdp_header->HB3) | + FIELD_PREP(PARITY_3_MASK, dp_utils_calculate_parity(sdp_header->HB3)); + + return length; +} |