1// SPDX-License-Identifier: MIT
  2/*
  3 * Copyright © 2020,2021 Intel Corporation
  4 */
  5
  6#include "i915_drv.h"
  7#include "intel_step.h"
  8
  9/*
 10 * KBL revision ID ordering is bizarre; higher revision ID's map to lower
 11 * steppings in some cases.  So rather than test against the revision ID
 12 * directly, let's map that into our own range of increasing ID's that we
 13 * can test against in a regular manner.
 14 */
 15
 16
 17/* FIXME: what about REVID_E0 */
 18static const struct intel_step_info kbl_revids[] = {
 19	[0] = { .gt_step = STEP_A0, .display_step = STEP_A0 },
 20	[1] = { .gt_step = STEP_B0, .display_step = STEP_B0 },
 21	[2] = { .gt_step = STEP_C0, .display_step = STEP_B0 },
 22	[3] = { .gt_step = STEP_D0, .display_step = STEP_B0 },
 23	[4] = { .gt_step = STEP_F0, .display_step = STEP_C0 },
 24	[5] = { .gt_step = STEP_C0, .display_step = STEP_B1 },
 25	[6] = { .gt_step = STEP_D1, .display_step = STEP_B1 },
 26	[7] = { .gt_step = STEP_G0, .display_step = STEP_C0 },
 27};
 28
 29static const struct intel_step_info tgl_uy_revid_step_tbl[] = {
 30	[0] = { .gt_step = STEP_A0, .display_step = STEP_A0 },
 31	[1] = { .gt_step = STEP_B0, .display_step = STEP_C0 },
 32	[2] = { .gt_step = STEP_B1, .display_step = STEP_C0 },
 33	[3] = { .gt_step = STEP_C0, .display_step = STEP_D0 },
 34};
 35
 36/* Same GT stepping between tgl_uy_revids and tgl_revids don't mean the same HW */
 37static const struct intel_step_info tgl_revid_step_tbl[] = {
 38	[0] = { .gt_step = STEP_A0, .display_step = STEP_B0 },
 39	[1] = { .gt_step = STEP_B0, .display_step = STEP_D0 },
 40};
 41
 42static const struct intel_step_info adls_revid_step_tbl[] = {
 43	[0x0] = { .gt_step = STEP_A0, .display_step = STEP_A0 },
 44	[0x1] = { .gt_step = STEP_A0, .display_step = STEP_A2 },
 45	[0x4] = { .gt_step = STEP_B0, .display_step = STEP_B0 },
 46	[0x8] = { .gt_step = STEP_C0, .display_step = STEP_B0 },
 47	[0xC] = { .gt_step = STEP_D0, .display_step = STEP_C0 },
 48};
 49
 50static const struct intel_step_info adlp_revid_step_tbl[] = {
 51	[0x0] = { .gt_step = STEP_A0, .display_step = STEP_A0 },
 52	[0x4] = { .gt_step = STEP_B0, .display_step = STEP_B0 },
 53	[0x8] = { .gt_step = STEP_C0, .display_step = STEP_C0 },
 54	[0xC] = { .gt_step = STEP_C0, .display_step = STEP_D0 },
 55};
 56
 57void intel_step_init(struct drm_i915_private *i915)
 58{
 59	const struct intel_step_info *revids = NULL;
 60	int size = 0;
 61	int revid = INTEL_REVID(i915);
 62	struct intel_step_info step = {};
 63
 64	if (IS_ALDERLAKE_P(i915)) {
 65		revids = adlp_revid_step_tbl;
 66		size = ARRAY_SIZE(adlp_revid_step_tbl);
 67	} else if (IS_ALDERLAKE_S(i915)) {
 68		revids = adls_revid_step_tbl;
 69		size = ARRAY_SIZE(adls_revid_step_tbl);
 70	} else if (IS_TGL_U(i915) || IS_TGL_Y(i915)) {
 71		revids = tgl_uy_revid_step_tbl;
 72		size = ARRAY_SIZE(tgl_uy_revid_step_tbl);
 73	} else if (IS_TIGERLAKE(i915)) {
 74		revids = tgl_revid_step_tbl;
 75		size = ARRAY_SIZE(tgl_revid_step_tbl);
 76	} else if (IS_KABYLAKE(i915)) {
 77		revids = kbl_revids;
 78		size = ARRAY_SIZE(kbl_revids);
 79	}
 80
 81	/* Not using the stepping scheme for the platform yet. */
 82	if (!revids)
 83		return;
 84
 85	if (revid < size && revids[revid].gt_step != STEP_NONE) {
 86		step = revids[revid];
 87	} else {
 88		drm_warn(&i915->drm, "Unknown revid 0x%02x\n", revid);
 89
 90		/*
 91		 * If we hit a gap in the revid array, use the information for
 92		 * the next revid.
 93		 *
 94		 * This may be wrong in all sorts of ways, especially if the
 95		 * steppings in the array are not monotonically increasing, but
 96		 * it's better than defaulting to 0.
 97		 */
 98		while (revid < size && revids[revid].gt_step == STEP_NONE)
 99			revid++;
100
101		if (revid < size) {
102			drm_dbg(&i915->drm, "Using steppings for revid 0x%02x\n",
103				revid);
104			step = revids[revid];
105		} else {
106			drm_dbg(&i915->drm, "Using future steppings\n");
107			step.gt_step = STEP_FUTURE;
108			step.display_step = STEP_FUTURE;
109		}
110	}
111
112	if (drm_WARN_ON(&i915->drm, step.gt_step == STEP_NONE))
113		return;
114
115	RUNTIME_INFO(i915)->step = step;
116}