1// SPDX-License-Identifier: MIT
  2/*
  3 * Copyright © 2013-2021 Intel Corporation
  4 */
  5
  6#include "i915_drv.h"
  7#include "i915_iosf_mbi.h"
  8#include "i915_reg.h"
  9#include "vlv_sideband.h"
 10
 11#include "display/intel_dpio_phy.h"
 12
 13/*
 14 * IOSF sideband, see VLV2_SidebandMsg_HAS.docx and
 15 * VLV_VLV2_PUNIT_HAS_0.8.docx
 16 */
 17
 18/* Standard MMIO read, non-posted */
 19#define SB_MRD_NP	0x00
 20/* Standard MMIO write, non-posted */
 21#define SB_MWR_NP	0x01
 22/* Private register read, double-word addressing, non-posted */
 23#define SB_CRRDDA_NP	0x06
 24/* Private register write, double-word addressing, non-posted */
 25#define SB_CRWRDA_NP	0x07
 26
 27static void ping(void *info)
 28{
 29}
 30
 31static void __vlv_punit_get(struct drm_i915_private *i915)
 32{
 33	iosf_mbi_punit_acquire();
 34
 35	/*
 36	 * Prevent the cpu from sleeping while we use this sideband, otherwise
 37	 * the punit may cause a machine hang. The issue appears to be isolated
 38	 * with changing the power state of the CPU package while changing
 39	 * the power state via the punit, and we have only observed it
 40	 * reliably on 4-core Baytail systems suggesting the issue is in the
 41	 * power delivery mechanism and likely to be board/function
 42	 * specific. Hence we presume the workaround needs only be applied
 43	 * to the Valleyview P-unit and not all sideband communications.
 44	 */
 45	if (IS_VALLEYVIEW(i915)) {
 46		cpu_latency_qos_update_request(&i915->sb_qos, 0);
 47		on_each_cpu(ping, NULL, 1);
 48	}
 49}
 50
 51static void __vlv_punit_put(struct drm_i915_private *i915)
 52{
 53	if (IS_VALLEYVIEW(i915))
 54		cpu_latency_qos_update_request(&i915->sb_qos,
 55					       PM_QOS_DEFAULT_VALUE);
 56
 57	iosf_mbi_punit_release();
 58}
 59
 60void vlv_iosf_sb_get(struct drm_i915_private *i915, unsigned long ports)
 61{
 62	if (ports & BIT(VLV_IOSF_SB_PUNIT))
 63		__vlv_punit_get(i915);
 64
 65	mutex_lock(&i915->sb_lock);
 66}
 67
 68void vlv_iosf_sb_put(struct drm_i915_private *i915, unsigned long ports)
 69{
 70	mutex_unlock(&i915->sb_lock);
 71
 72	if (ports & BIT(VLV_IOSF_SB_PUNIT))
 73		__vlv_punit_put(i915);
 74}
 75
 76static int vlv_sideband_rw(struct drm_i915_private *i915,
 77			   u32 devfn, u32 port, u32 opcode,
 78			   u32 addr, u32 *val)
 79{
 80	struct intel_uncore *uncore = &i915->uncore;
 81	const bool is_read = (opcode == SB_MRD_NP || opcode == SB_CRRDDA_NP);
 82	int err;
 83
 84	lockdep_assert_held(&i915->sb_lock);
 85	if (port == IOSF_PORT_PUNIT)
 86		iosf_mbi_assert_punit_acquired();
 87
 88	/* Flush the previous comms, just in case it failed last time. */
 89	if (intel_wait_for_register(uncore,
 90				    VLV_IOSF_DOORBELL_REQ, IOSF_SB_BUSY, 0,
 91				    5)) {
 92		drm_dbg(&i915->drm, "IOSF sideband idle wait (%s) timed out\n",
 93			is_read ? "read" : "write");
 94		return -EAGAIN;
 95	}
 96
 97	preempt_disable();
 98
 99	intel_uncore_write_fw(uncore, VLV_IOSF_ADDR, addr);
100	intel_uncore_write_fw(uncore, VLV_IOSF_DATA, is_read ? 0 : *val);
101	intel_uncore_write_fw(uncore, VLV_IOSF_DOORBELL_REQ,
102			      (devfn << IOSF_DEVFN_SHIFT) |
103			      (opcode << IOSF_OPCODE_SHIFT) |
104			      (port << IOSF_PORT_SHIFT) |
105			      (0xf << IOSF_BYTE_ENABLES_SHIFT) |
106			      (0 << IOSF_BAR_SHIFT) |
107			      IOSF_SB_BUSY);
108
109	if (__intel_wait_for_register_fw(uncore,
110					 VLV_IOSF_DOORBELL_REQ, IOSF_SB_BUSY, 0,
111					 10000, 0, NULL) == 0) {
112		if (is_read)
113			*val = intel_uncore_read_fw(uncore, VLV_IOSF_DATA);
114		err = 0;
115	} else {
116		drm_dbg(&i915->drm, "IOSF sideband finish wait (%s) timed out\n",
117			is_read ? "read" : "write");
118		err = -ETIMEDOUT;
119	}
120
121	preempt_enable();
122
123	return err;
124}
125
126u32 vlv_punit_read(struct drm_i915_private *i915, u32 addr)
127{
128	u32 val = 0;
129
130	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT,
131			SB_CRRDDA_NP, addr, &val);
132
133	return val;
134}
135
136int vlv_punit_write(struct drm_i915_private *i915, u32 addr, u32 val)
137{
138	return vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT,
139			       SB_CRWRDA_NP, addr, &val);
140}
141
142u32 vlv_bunit_read(struct drm_i915_private *i915, u32 reg)
143{
144	u32 val = 0;
145
146	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_BUNIT,
147			SB_CRRDDA_NP, reg, &val);
148
149	return val;
150}
151
152void vlv_bunit_write(struct drm_i915_private *i915, u32 reg, u32 val)
153{
154	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_BUNIT,
155			SB_CRWRDA_NP, reg, &val);
156}
157
158u32 vlv_nc_read(struct drm_i915_private *i915, u8 addr)
159{
160	u32 val = 0;
161
162	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_NC,
163			SB_CRRDDA_NP, addr, &val);
164
165	return val;
166}
167
168u32 vlv_cck_read(struct drm_i915_private *i915, u32 reg)
169{
170	u32 val = 0;
171
172	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCK,
173			SB_CRRDDA_NP, reg, &val);
174
175	return val;
176}
177
178void vlv_cck_write(struct drm_i915_private *i915, u32 reg, u32 val)
179{
180	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCK,
181			SB_CRWRDA_NP, reg, &val);
182}
183
184u32 vlv_ccu_read(struct drm_i915_private *i915, u32 reg)
185{
186	u32 val = 0;
187
188	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCU,
189			SB_CRRDDA_NP, reg, &val);
190
191	return val;
192}
193
194void vlv_ccu_write(struct drm_i915_private *i915, u32 reg, u32 val)
195{
196	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCU,
197			SB_CRWRDA_NP, reg, &val);
198}
199
200static u32 vlv_dpio_phy_iosf_port(struct drm_i915_private *i915, enum dpio_phy phy)
201{
202	/*
203	 * IOSF_PORT_DPIO: VLV x2 PHY (DP/HDMI B and C), CHV x1 PHY (DP/HDMI D)
204	 * IOSF_PORT_DPIO_2: CHV x2 PHY (DP/HDMI B and C)
205	 */
206	if (IS_CHERRYVIEW(i915))
207		return phy == DPIO_PHY0 ? IOSF_PORT_DPIO_2 : IOSF_PORT_DPIO;
208	else
209		return IOSF_PORT_DPIO;
210}
211
212u32 vlv_dpio_read(struct drm_i915_private *i915, enum dpio_phy phy, int reg)
213{
214	u32 port = vlv_dpio_phy_iosf_port(i915, phy);
215	u32 val = 0;
216
217	vlv_sideband_rw(i915, DPIO_DEVFN, port, SB_MRD_NP, reg, &val);
218
219	/*
220	 * FIXME: There might be some registers where all 1's is a valid value,
221	 * so ideally we should check the register offset instead...
222	 */
223	drm_WARN(&i915->drm, val == 0xffffffff,
224		 "DPIO PHY%d read reg 0x%x == 0x%x\n",
225		 phy, reg, val);
226
227	return val;
228}
229
230void vlv_dpio_write(struct drm_i915_private *i915,
231		    enum dpio_phy phy, int reg, u32 val)
232{
233	u32 port = vlv_dpio_phy_iosf_port(i915, phy);
234
235	vlv_sideband_rw(i915, DPIO_DEVFN, port, SB_MWR_NP, reg, &val);
236}
237
238u32 vlv_flisdsi_read(struct drm_i915_private *i915, u32 reg)
239{
240	u32 val = 0;
241
242	vlv_sideband_rw(i915, DPIO_DEVFN, IOSF_PORT_FLISDSI, SB_CRRDDA_NP,
243			reg, &val);
244	return val;
245}
246
247void vlv_flisdsi_write(struct drm_i915_private *i915, u32 reg, u32 val)
248{
249	vlv_sideband_rw(i915, DPIO_DEVFN, IOSF_PORT_FLISDSI, SB_CRWRDA_NP,
250			reg, &val);
251}