1/*
2 * Copyright © 2016 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 * Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
25 * Jerome Anand <jerome.anand@intel.com>
26 * based on VED patches
27 *
28 */
29
30/**
31 * DOC: LPE Audio integration for HDMI or DP playback
32 *
33 * Motivation:
34 * Atom platforms (e.g. valleyview and cherryTrail) integrates a DMA-based
35 * interface as an alternative to the traditional HDaudio path. While this
36 * mode is unrelated to the LPE aka SST audio engine, the documentation refers
37 * to this mode as LPE so we keep this notation for the sake of consistency.
38 *
39 * The interface is handled by a separate standalone driver maintained in the
40 * ALSA subsystem for simplicity. To minimize the interaction between the two
41 * subsystems, a bridge is setup between the hdmi-lpe-audio and i915:
42 * 1. Create a platform device to share MMIO/IRQ resources
43 * 2. Make the platform device child of i915 device for runtime PM.
44 * 3. Create IRQ chip to forward the LPE audio irqs.
45 * the hdmi-lpe-audio driver probes the lpe audio device and creates a new
46 * sound card
47 *
48 * Threats:
49 * Due to the restriction in Linux platform device model, user need manually
50 * uninstall the hdmi-lpe-audio driver before uninstalling i915 module,
51 * otherwise we might run into use-after-free issues after i915 removes the
52 * platform device: even though hdmi-lpe-audio driver is released, the modules
53 * is still in "installed" status.
54 *
55 * Implementation:
56 * The MMIO/REG platform resources are created according to the registers
57 * specification.
58 * When forwarding LPE audio irqs, the flow control handler selection depends
59 * on the platform, for example on valleyview handle_simple_irq is enough.
60 *
61 */
62
63#include <linux/acpi.h>
64#include <linux/delay.h>
65#include <linux/device.h>
66#include <linux/irq.h>
67#include <linux/pci.h>
68#include <linux/platform_device.h>
69#include <linux/pm_runtime.h>
70
71#include <drm/drm_print.h>
72#include <drm/intel/intel_lpe_audio.h>
73
74#include "i915_irq.h"
75#include "intel_audio_regs.h"
76#include "intel_de.h"
77#include "intel_lpe_audio.h"
78#include "intel_pci_config.h"
79
80#define HAS_LPE_AUDIO(display) ((display)->audio.lpe.platdev)
81
82static struct platform_device *
83lpe_audio_platdev_create(struct intel_display *display)
84{
85 struct pci_dev *pdev = to_pci_dev(display->drm->dev);
86 struct platform_device_info pinfo = {};
87 struct resource *rsc;
88 struct platform_device *platdev;
89 struct intel_hdmi_lpe_audio_pdata *pdata;
90
91 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
92 if (!pdata)
93 return ERR_PTR(error: -ENOMEM);
94
95 rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL);
96 if (!rsc) {
97 kfree(objp: pdata);
98 return ERR_PTR(error: -ENOMEM);
99 }
100
101 rsc[0].start = display->audio.lpe.irq;
102 rsc[0].end = display->audio.lpe.irq;
103 rsc[0].flags = IORESOURCE_IRQ;
104 rsc[0].name = "hdmi-lpe-audio-irq";
105
106 rsc[1].start = pci_resource_start(pdev, GEN4_GTTMMADR_BAR) +
107 I915_HDMI_LPE_AUDIO_BASE;
108 rsc[1].end = pci_resource_start(pdev, GEN4_GTTMMADR_BAR) +
109 I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
110 rsc[1].flags = IORESOURCE_MEM;
111 rsc[1].name = "hdmi-lpe-audio-mmio";
112
113 pinfo.parent = display->drm->dev;
114 pinfo.name = "hdmi-lpe-audio";
115 pinfo.id = -1;
116 pinfo.res = rsc;
117 pinfo.num_res = 2;
118 pinfo.data = pdata;
119 pinfo.size_data = sizeof(*pdata);
120 pinfo.dma_mask = DMA_BIT_MASK(32);
121
122 pdata->num_pipes = INTEL_NUM_PIPES(display);
123 pdata->num_ports = display->platform.cherryview ? 3 : 2; /* B,C,D or B,C */
124 pdata->port[0].pipe = -1;
125 pdata->port[1].pipe = -1;
126 pdata->port[2].pipe = -1;
127 spin_lock_init(&pdata->lpe_audio_slock);
128
129 platdev = platform_device_register_full(pdevinfo: &pinfo);
130 kfree(objp: rsc);
131 kfree(objp: pdata);
132
133 if (IS_ERR(ptr: platdev)) {
134 drm_err(display->drm,
135 "Failed to allocate LPE audio platform device\n");
136 return platdev;
137 }
138
139 pm_runtime_no_callbacks(dev: &platdev->dev);
140
141 return platdev;
142}
143
144static void lpe_audio_platdev_destroy(struct intel_display *display)
145{
146 /* XXX Note that platform_device_register_full() allocates a dma_mask
147 * and never frees it. We can't free it here as we cannot guarantee
148 * this is the last reference (i.e. that the dma_mask will not be
149 * used after our unregister). So ee choose to leak the sizeof(u64)
150 * allocation here - it should be fixed in the platform_device rather
151 * than us fiddle with its internals.
152 */
153
154 platform_device_unregister(display->audio.lpe.platdev);
155}
156
157static void lpe_audio_irq_unmask(struct irq_data *d)
158{
159}
160
161static void lpe_audio_irq_mask(struct irq_data *d)
162{
163}
164
165static struct irq_chip lpe_audio_irqchip = {
166 .name = "hdmi_lpe_audio_irqchip",
167 .irq_mask = lpe_audio_irq_mask,
168 .irq_unmask = lpe_audio_irq_unmask,
169};
170
171static int lpe_audio_irq_init(struct intel_display *display)
172{
173 int irq = display->audio.lpe.irq;
174
175 irq_set_chip_and_handler_name(irq, chip: &lpe_audio_irqchip,
176 handle: handle_simple_irq,
177 name: "hdmi_lpe_audio_irq_handler");
178
179 return 0;
180}
181
182static bool lpe_audio_detect(struct intel_display *display)
183{
184 int lpe_present = false;
185
186 if (display->platform.valleyview || display->platform.cherryview) {
187 static const struct pci_device_id atom_hdaudio_ids[] = {
188 /* Baytrail */
189 {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
190 /* Braswell */
191 {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
192 {}
193 };
194
195 if (!pci_dev_present(ids: atom_hdaudio_ids)) {
196 drm_info(display->drm,
197 "HDaudio controller not detected, using LPE audio instead\n");
198 lpe_present = true;
199 }
200 }
201 return lpe_present;
202}
203
204static int lpe_audio_setup(struct intel_display *display)
205{
206 int ret;
207
208 display->audio.lpe.irq = irq_alloc_desc(0);
209 if (display->audio.lpe.irq < 0) {
210 drm_err(display->drm, "Failed to allocate IRQ desc: %d\n",
211 display->audio.lpe.irq);
212 ret = display->audio.lpe.irq;
213 goto err;
214 }
215
216 drm_dbg(display->drm, "irq = %d\n", display->audio.lpe.irq);
217
218 ret = lpe_audio_irq_init(display);
219
220 if (ret) {
221 drm_err(display->drm,
222 "Failed to initialize irqchip for lpe audio: %d\n",
223 ret);
224 goto err_free_irq;
225 }
226
227 display->audio.lpe.platdev = lpe_audio_platdev_create(display);
228
229 if (IS_ERR(ptr: display->audio.lpe.platdev)) {
230 ret = PTR_ERR(ptr: display->audio.lpe.platdev);
231 drm_err(display->drm,
232 "Failed to create lpe audio platform device: %d\n",
233 ret);
234 goto err_free_irq;
235 }
236
237 /* enable chicken bit; at least this is required for Dell Wyse 3040
238 * with DP outputs (but only sometimes by some reason!)
239 */
240 intel_de_write(display, VLV_AUD_CHICKEN_BIT_REG,
241 VLV_CHICKEN_BIT_DBG_ENABLE);
242
243 return 0;
244err_free_irq:
245 irq_free_desc(irq: display->audio.lpe.irq);
246err:
247 display->audio.lpe.irq = -1;
248 display->audio.lpe.platdev = NULL;
249 return ret;
250}
251
252/**
253 * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
254 * @display: display device
255 *
256 * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
257 * driver.
258 */
259void intel_lpe_audio_irq_handler(struct intel_display *display)
260{
261 int ret;
262
263 if (!HAS_LPE_AUDIO(display))
264 return;
265
266 ret = generic_handle_irq(irq: display->audio.lpe.irq);
267 if (ret)
268 drm_err_ratelimited(display->drm,
269 "error handling LPE audio irq: %d\n", ret);
270}
271
272/**
273 * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
274 * driver and i915
275 * @display: display device
276 *
277 * Return: 0 if successful. non-zero if detection or
278 * llocation/initialization fails
279 */
280int intel_lpe_audio_init(struct intel_display *display)
281{
282 int ret = -ENODEV;
283
284 if (lpe_audio_detect(display)) {
285 ret = lpe_audio_setup(display);
286 if (ret < 0)
287 drm_err(display->drm,
288 "failed to setup LPE Audio bridge\n");
289 }
290 return ret;
291}
292
293/**
294 * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
295 * audio driver and i915
296 * @display: display device
297 *
298 * release all the resources for LPE audio <-> i915 bridge.
299 */
300void intel_lpe_audio_teardown(struct intel_display *display)
301{
302 if (!HAS_LPE_AUDIO(display))
303 return;
304
305 lpe_audio_platdev_destroy(display);
306
307 irq_free_desc(irq: display->audio.lpe.irq);
308
309 display->audio.lpe.irq = -1;
310 display->audio.lpe.platdev = NULL;
311}
312
313/**
314 * intel_lpe_audio_notify() - notify lpe audio event
315 * audio driver and i915
316 * @display: display device
317 * @cpu_transcoder: CPU transcoder
318 * @port: port
319 * @eld : ELD data
320 * @ls_clock: Link symbol clock in kHz
321 * @dp_output: Driving a DP output?
322 *
323 * Notify lpe audio driver of eld change.
324 */
325void intel_lpe_audio_notify(struct intel_display *display,
326 enum transcoder cpu_transcoder, enum port port,
327 const void *eld, int ls_clock, bool dp_output)
328{
329 unsigned long irqflags;
330 struct intel_hdmi_lpe_audio_pdata *pdata;
331 struct intel_hdmi_lpe_audio_port_pdata *ppdata;
332 u32 audio_enable;
333
334 if (!HAS_LPE_AUDIO(display))
335 return;
336
337 pdata = dev_get_platdata(dev: &display->audio.lpe.platdev->dev);
338 ppdata = &pdata->port[port - PORT_B];
339
340 spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
341
342 audio_enable = intel_de_read(display, VLV_AUD_PORT_EN_DBG(port));
343
344 if (eld != NULL) {
345 memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
346 ppdata->pipe = cpu_transcoder;
347 ppdata->ls_clock = ls_clock;
348 ppdata->dp_output = dp_output;
349
350 /* Unmute the amp for both DP and HDMI */
351 intel_de_write(display, VLV_AUD_PORT_EN_DBG(port),
352 val: audio_enable & ~VLV_AMP_MUTE);
353 } else {
354 memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
355 ppdata->pipe = -1;
356 ppdata->ls_clock = 0;
357 ppdata->dp_output = false;
358
359 /* Mute the amp for both DP and HDMI */
360 intel_de_write(display, VLV_AUD_PORT_EN_DBG(port),
361 val: audio_enable | VLV_AMP_MUTE);
362 }
363
364 if (pdata->notify_audio_lpe)
365 pdata->notify_audio_lpe(display->audio.lpe.platdev, port - PORT_B);
366
367 spin_unlock_irqrestore(lock: &pdata->lpe_audio_slock, flags: irqflags);
368}
369

source code of linux/drivers/gpu/drm/i915/display/intel_lpe_audio.c