xref: /openbmc/linux/sound/soc/tegra/tegra30_ahub.c (revision 97da55fc)
1 /*
2  * tegra30_ahub.c - Tegra30 AHUB driver
3  *
4  * Copyright (c) 2011,2012, NVIDIA CORPORATION.  All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <linux/clk.h>
20 #include <linux/device.h>
21 #include <linux/io.h>
22 #include <linux/module.h>
23 #include <linux/of_platform.h>
24 #include <linux/platform_device.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/regmap.h>
27 #include <linux/slab.h>
28 #include <linux/clk/tegra.h>
29 #include <sound/soc.h>
30 #include "tegra30_ahub.h"
31 
32 #define DRV_NAME "tegra30-ahub"
33 
34 static struct tegra30_ahub *ahub;
35 
36 static inline void tegra30_apbif_write(u32 reg, u32 val)
37 {
38 	regmap_write(ahub->regmap_apbif, reg, val);
39 }
40 
41 static inline u32 tegra30_apbif_read(u32 reg)
42 {
43 	u32 val;
44 	regmap_read(ahub->regmap_apbif, reg, &val);
45 	return val;
46 }
47 
48 static inline void tegra30_audio_write(u32 reg, u32 val)
49 {
50 	regmap_write(ahub->regmap_ahub, reg, val);
51 }
52 
53 static int tegra30_ahub_runtime_suspend(struct device *dev)
54 {
55 	regcache_cache_only(ahub->regmap_apbif, true);
56 	regcache_cache_only(ahub->regmap_ahub, true);
57 
58 	clk_disable_unprepare(ahub->clk_apbif);
59 	clk_disable_unprepare(ahub->clk_d_audio);
60 
61 	return 0;
62 }
63 
64 /*
65  * clk_apbif isn't required for an I2S<->I2S configuration where no PCM data
66  * is read from or sent to memory. However, that's not something the rest of
67  * the driver supports right now, so we'll just treat the two clocks as one
68  * for now.
69  *
70  * These functions should not be a plain ref-count. Instead, each active stream
71  * contributes some requirement to the minimum clock rate, so starting or
72  * stopping streams should dynamically adjust the clock as required.  However,
73  * this is not yet implemented.
74  */
75 static int tegra30_ahub_runtime_resume(struct device *dev)
76 {
77 	int ret;
78 
79 	ret = clk_prepare_enable(ahub->clk_d_audio);
80 	if (ret) {
81 		dev_err(dev, "clk_enable d_audio failed: %d\n", ret);
82 		return ret;
83 	}
84 	ret = clk_prepare_enable(ahub->clk_apbif);
85 	if (ret) {
86 		dev_err(dev, "clk_enable apbif failed: %d\n", ret);
87 		clk_disable(ahub->clk_d_audio);
88 		return ret;
89 	}
90 
91 	regcache_cache_only(ahub->regmap_apbif, false);
92 	regcache_cache_only(ahub->regmap_ahub, false);
93 
94 	return 0;
95 }
96 
97 int tegra30_ahub_allocate_rx_fifo(enum tegra30_ahub_rxcif *rxcif,
98 				  unsigned long *fiforeg,
99 				  unsigned long *reqsel)
100 {
101 	int channel;
102 	u32 reg, val;
103 
104 	channel = find_first_zero_bit(ahub->rx_usage,
105 				      TEGRA30_AHUB_CHANNEL_CTRL_COUNT);
106 	if (channel >= TEGRA30_AHUB_CHANNEL_CTRL_COUNT)
107 		return -EBUSY;
108 
109 	__set_bit(channel, ahub->rx_usage);
110 
111 	*rxcif = TEGRA30_AHUB_RXCIF_APBIF_RX0 + channel;
112 	*fiforeg = ahub->apbif_addr + TEGRA30_AHUB_CHANNEL_RXFIFO +
113 		   (channel * TEGRA30_AHUB_CHANNEL_RXFIFO_STRIDE);
114 	*reqsel = ahub->dma_sel + channel;
115 
116 	reg = TEGRA30_AHUB_CHANNEL_CTRL +
117 	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
118 	val = tegra30_apbif_read(reg);
119 	val &= ~(TEGRA30_AHUB_CHANNEL_CTRL_RX_THRESHOLD_MASK |
120 		 TEGRA30_AHUB_CHANNEL_CTRL_RX_PACK_MASK);
121 	val |= (7 << TEGRA30_AHUB_CHANNEL_CTRL_RX_THRESHOLD_SHIFT) |
122 	       TEGRA30_AHUB_CHANNEL_CTRL_RX_PACK_EN |
123 	       TEGRA30_AHUB_CHANNEL_CTRL_RX_PACK_16;
124 	tegra30_apbif_write(reg, val);
125 
126 	reg = TEGRA30_AHUB_CIF_RX_CTRL +
127 	      (channel * TEGRA30_AHUB_CIF_RX_CTRL_STRIDE);
128 	val = (0 << TEGRA30_AUDIOCIF_CTRL_FIFO_THRESHOLD_SHIFT) |
129 	      (1 << TEGRA30_AUDIOCIF_CTRL_AUDIO_CHANNELS_SHIFT) |
130 	      (1 << TEGRA30_AUDIOCIF_CTRL_CLIENT_CHANNELS_SHIFT) |
131 	      TEGRA30_AUDIOCIF_CTRL_AUDIO_BITS_16 |
132 	      TEGRA30_AUDIOCIF_CTRL_CLIENT_BITS_16 |
133 	      TEGRA30_AUDIOCIF_CTRL_DIRECTION_RX;
134 	tegra30_apbif_write(reg, val);
135 
136 	return 0;
137 }
138 EXPORT_SYMBOL_GPL(tegra30_ahub_allocate_rx_fifo);
139 
140 int tegra30_ahub_enable_rx_fifo(enum tegra30_ahub_rxcif rxcif)
141 {
142 	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
143 	int reg, val;
144 
145 	reg = TEGRA30_AHUB_CHANNEL_CTRL +
146 	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
147 	val = tegra30_apbif_read(reg);
148 	val |= TEGRA30_AHUB_CHANNEL_CTRL_RX_EN;
149 	tegra30_apbif_write(reg, val);
150 
151 	return 0;
152 }
153 EXPORT_SYMBOL_GPL(tegra30_ahub_enable_rx_fifo);
154 
155 int tegra30_ahub_disable_rx_fifo(enum tegra30_ahub_rxcif rxcif)
156 {
157 	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
158 	int reg, val;
159 
160 	reg = TEGRA30_AHUB_CHANNEL_CTRL +
161 	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
162 	val = tegra30_apbif_read(reg);
163 	val &= ~TEGRA30_AHUB_CHANNEL_CTRL_RX_EN;
164 	tegra30_apbif_write(reg, val);
165 
166 	return 0;
167 }
168 EXPORT_SYMBOL_GPL(tegra30_ahub_disable_rx_fifo);
169 
170 int tegra30_ahub_free_rx_fifo(enum tegra30_ahub_rxcif rxcif)
171 {
172 	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
173 
174 	__clear_bit(channel, ahub->rx_usage);
175 
176 	return 0;
177 }
178 EXPORT_SYMBOL_GPL(tegra30_ahub_free_rx_fifo);
179 
180 int tegra30_ahub_allocate_tx_fifo(enum tegra30_ahub_txcif *txcif,
181 				  unsigned long *fiforeg,
182 				  unsigned long *reqsel)
183 {
184 	int channel;
185 	u32 reg, val;
186 
187 	channel = find_first_zero_bit(ahub->tx_usage,
188 				      TEGRA30_AHUB_CHANNEL_CTRL_COUNT);
189 	if (channel >= TEGRA30_AHUB_CHANNEL_CTRL_COUNT)
190 		return -EBUSY;
191 
192 	__set_bit(channel, ahub->tx_usage);
193 
194 	*txcif = TEGRA30_AHUB_TXCIF_APBIF_TX0 + channel;
195 	*fiforeg = ahub->apbif_addr + TEGRA30_AHUB_CHANNEL_TXFIFO +
196 		   (channel * TEGRA30_AHUB_CHANNEL_TXFIFO_STRIDE);
197 	*reqsel = ahub->dma_sel + channel;
198 
199 	reg = TEGRA30_AHUB_CHANNEL_CTRL +
200 	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
201 	val = tegra30_apbif_read(reg);
202 	val &= ~(TEGRA30_AHUB_CHANNEL_CTRL_TX_THRESHOLD_MASK |
203 		 TEGRA30_AHUB_CHANNEL_CTRL_TX_PACK_MASK);
204 	val |= (7 << TEGRA30_AHUB_CHANNEL_CTRL_TX_THRESHOLD_SHIFT) |
205 	       TEGRA30_AHUB_CHANNEL_CTRL_TX_PACK_EN |
206 	       TEGRA30_AHUB_CHANNEL_CTRL_TX_PACK_16;
207 	tegra30_apbif_write(reg, val);
208 
209 	reg = TEGRA30_AHUB_CIF_TX_CTRL +
210 	      (channel * TEGRA30_AHUB_CIF_TX_CTRL_STRIDE);
211 	val = (0 << TEGRA30_AUDIOCIF_CTRL_FIFO_THRESHOLD_SHIFT) |
212 	      (1 << TEGRA30_AUDIOCIF_CTRL_AUDIO_CHANNELS_SHIFT) |
213 	      (1 << TEGRA30_AUDIOCIF_CTRL_CLIENT_CHANNELS_SHIFT) |
214 	      TEGRA30_AUDIOCIF_CTRL_AUDIO_BITS_16 |
215 	      TEGRA30_AUDIOCIF_CTRL_CLIENT_BITS_16 |
216 	      TEGRA30_AUDIOCIF_CTRL_DIRECTION_TX;
217 	tegra30_apbif_write(reg, val);
218 
219 	return 0;
220 }
221 EXPORT_SYMBOL_GPL(tegra30_ahub_allocate_tx_fifo);
222 
223 int tegra30_ahub_enable_tx_fifo(enum tegra30_ahub_txcif txcif)
224 {
225 	int channel = txcif - TEGRA30_AHUB_TXCIF_APBIF_TX0;
226 	int reg, val;
227 
228 	reg = TEGRA30_AHUB_CHANNEL_CTRL +
229 	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
230 	val = tegra30_apbif_read(reg);
231 	val |= TEGRA30_AHUB_CHANNEL_CTRL_TX_EN;
232 	tegra30_apbif_write(reg, val);
233 
234 	return 0;
235 }
236 EXPORT_SYMBOL_GPL(tegra30_ahub_enable_tx_fifo);
237 
238 int tegra30_ahub_disable_tx_fifo(enum tegra30_ahub_txcif txcif)
239 {
240 	int channel = txcif - TEGRA30_AHUB_TXCIF_APBIF_TX0;
241 	int reg, val;
242 
243 	reg = TEGRA30_AHUB_CHANNEL_CTRL +
244 	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
245 	val = tegra30_apbif_read(reg);
246 	val &= ~TEGRA30_AHUB_CHANNEL_CTRL_TX_EN;
247 	tegra30_apbif_write(reg, val);
248 
249 	return 0;
250 }
251 EXPORT_SYMBOL_GPL(tegra30_ahub_disable_tx_fifo);
252 
253 int tegra30_ahub_free_tx_fifo(enum tegra30_ahub_txcif txcif)
254 {
255 	int channel = txcif - TEGRA30_AHUB_TXCIF_APBIF_TX0;
256 
257 	__clear_bit(channel, ahub->tx_usage);
258 
259 	return 0;
260 }
261 EXPORT_SYMBOL_GPL(tegra30_ahub_free_tx_fifo);
262 
263 int tegra30_ahub_set_rx_cif_source(enum tegra30_ahub_rxcif rxcif,
264 				   enum tegra30_ahub_txcif txcif)
265 {
266 	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
267 	int reg;
268 
269 	reg = TEGRA30_AHUB_AUDIO_RX +
270 	      (channel * TEGRA30_AHUB_AUDIO_RX_STRIDE);
271 	tegra30_audio_write(reg, 1 << txcif);
272 
273 	return 0;
274 }
275 EXPORT_SYMBOL_GPL(tegra30_ahub_set_rx_cif_source);
276 
277 int tegra30_ahub_unset_rx_cif_source(enum tegra30_ahub_rxcif rxcif)
278 {
279 	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
280 	int reg;
281 
282 	reg = TEGRA30_AHUB_AUDIO_RX +
283 	      (channel * TEGRA30_AHUB_AUDIO_RX_STRIDE);
284 	tegra30_audio_write(reg, 0);
285 
286 	return 0;
287 }
288 EXPORT_SYMBOL_GPL(tegra30_ahub_unset_rx_cif_source);
289 
290 static const char * const configlink_clocks[] = {
291 	"i2s0",
292 	"i2s1",
293 	"i2s2",
294 	"i2s3",
295 	"i2s4",
296 	"dam0",
297 	"dam1",
298 	"dam2",
299 	"spdif_in",
300 };
301 
302 #define LAST_REG(name) \
303 	(TEGRA30_AHUB_##name + \
304 	 (TEGRA30_AHUB_##name##_STRIDE * TEGRA30_AHUB_##name##_COUNT) - 4)
305 
306 #define REG_IN_ARRAY(reg, name) \
307 	((reg >= TEGRA30_AHUB_##name) && \
308 	 (reg <= LAST_REG(name) && \
309 	 (!((reg - TEGRA30_AHUB_##name) % TEGRA30_AHUB_##name##_STRIDE))))
310 
311 static bool tegra30_ahub_apbif_wr_rd_reg(struct device *dev, unsigned int reg)
312 {
313 	switch (reg) {
314 	case TEGRA30_AHUB_CONFIG_LINK_CTRL:
315 	case TEGRA30_AHUB_MISC_CTRL:
316 	case TEGRA30_AHUB_APBDMA_LIVE_STATUS:
317 	case TEGRA30_AHUB_I2S_LIVE_STATUS:
318 	case TEGRA30_AHUB_SPDIF_LIVE_STATUS:
319 	case TEGRA30_AHUB_I2S_INT_MASK:
320 	case TEGRA30_AHUB_DAM_INT_MASK:
321 	case TEGRA30_AHUB_SPDIF_INT_MASK:
322 	case TEGRA30_AHUB_APBIF_INT_MASK:
323 	case TEGRA30_AHUB_I2S_INT_STATUS:
324 	case TEGRA30_AHUB_DAM_INT_STATUS:
325 	case TEGRA30_AHUB_SPDIF_INT_STATUS:
326 	case TEGRA30_AHUB_APBIF_INT_STATUS:
327 	case TEGRA30_AHUB_I2S_INT_SOURCE:
328 	case TEGRA30_AHUB_DAM_INT_SOURCE:
329 	case TEGRA30_AHUB_SPDIF_INT_SOURCE:
330 	case TEGRA30_AHUB_APBIF_INT_SOURCE:
331 	case TEGRA30_AHUB_I2S_INT_SET:
332 	case TEGRA30_AHUB_DAM_INT_SET:
333 	case TEGRA30_AHUB_SPDIF_INT_SET:
334 	case TEGRA30_AHUB_APBIF_INT_SET:
335 		return true;
336 	default:
337 		break;
338 	};
339 
340 	if (REG_IN_ARRAY(reg, CHANNEL_CTRL) ||
341 	    REG_IN_ARRAY(reg, CHANNEL_CLEAR) ||
342 	    REG_IN_ARRAY(reg, CHANNEL_STATUS) ||
343 	    REG_IN_ARRAY(reg, CHANNEL_TXFIFO) ||
344 	    REG_IN_ARRAY(reg, CHANNEL_RXFIFO) ||
345 	    REG_IN_ARRAY(reg, CIF_TX_CTRL) ||
346 	    REG_IN_ARRAY(reg, CIF_RX_CTRL) ||
347 	    REG_IN_ARRAY(reg, DAM_LIVE_STATUS))
348 		return true;
349 
350 	return false;
351 }
352 
353 static bool tegra30_ahub_apbif_volatile_reg(struct device *dev,
354 					    unsigned int reg)
355 {
356 	switch (reg) {
357 	case TEGRA30_AHUB_CONFIG_LINK_CTRL:
358 	case TEGRA30_AHUB_MISC_CTRL:
359 	case TEGRA30_AHUB_APBDMA_LIVE_STATUS:
360 	case TEGRA30_AHUB_I2S_LIVE_STATUS:
361 	case TEGRA30_AHUB_SPDIF_LIVE_STATUS:
362 	case TEGRA30_AHUB_I2S_INT_STATUS:
363 	case TEGRA30_AHUB_DAM_INT_STATUS:
364 	case TEGRA30_AHUB_SPDIF_INT_STATUS:
365 	case TEGRA30_AHUB_APBIF_INT_STATUS:
366 	case TEGRA30_AHUB_I2S_INT_SET:
367 	case TEGRA30_AHUB_DAM_INT_SET:
368 	case TEGRA30_AHUB_SPDIF_INT_SET:
369 	case TEGRA30_AHUB_APBIF_INT_SET:
370 		return true;
371 	default:
372 		break;
373 	};
374 
375 	if (REG_IN_ARRAY(reg, CHANNEL_CLEAR) ||
376 	    REG_IN_ARRAY(reg, CHANNEL_STATUS) ||
377 	    REG_IN_ARRAY(reg, CHANNEL_TXFIFO) ||
378 	    REG_IN_ARRAY(reg, CHANNEL_RXFIFO) ||
379 	    REG_IN_ARRAY(reg, DAM_LIVE_STATUS))
380 		return true;
381 
382 	return false;
383 }
384 
385 static bool tegra30_ahub_apbif_precious_reg(struct device *dev,
386 					    unsigned int reg)
387 {
388 	if (REG_IN_ARRAY(reg, CHANNEL_TXFIFO) ||
389 	    REG_IN_ARRAY(reg, CHANNEL_RXFIFO))
390 		return true;
391 
392 	return false;
393 }
394 
395 static const struct regmap_config tegra30_ahub_apbif_regmap_config = {
396 	.name = "apbif",
397 	.reg_bits = 32,
398 	.val_bits = 32,
399 	.reg_stride = 4,
400 	.max_register = TEGRA30_AHUB_APBIF_INT_SET,
401 	.writeable_reg = tegra30_ahub_apbif_wr_rd_reg,
402 	.readable_reg = tegra30_ahub_apbif_wr_rd_reg,
403 	.volatile_reg = tegra30_ahub_apbif_volatile_reg,
404 	.precious_reg = tegra30_ahub_apbif_precious_reg,
405 	.cache_type = REGCACHE_RBTREE,
406 };
407 
408 static bool tegra30_ahub_ahub_wr_rd_reg(struct device *dev, unsigned int reg)
409 {
410 	if (REG_IN_ARRAY(reg, AUDIO_RX))
411 		return true;
412 
413 	return false;
414 }
415 
416 static const struct regmap_config tegra30_ahub_ahub_regmap_config = {
417 	.name = "ahub",
418 	.reg_bits = 32,
419 	.val_bits = 32,
420 	.reg_stride = 4,
421 	.max_register = LAST_REG(AUDIO_RX),
422 	.writeable_reg = tegra30_ahub_ahub_wr_rd_reg,
423 	.readable_reg = tegra30_ahub_ahub_wr_rd_reg,
424 	.cache_type = REGCACHE_RBTREE,
425 };
426 
427 static int tegra30_ahub_probe(struct platform_device *pdev)
428 {
429 	struct clk *clk;
430 	int i;
431 	struct resource *res0, *res1, *region;
432 	u32 of_dma[2];
433 	void __iomem *regs_apbif, *regs_ahub;
434 	int ret = 0;
435 
436 	if (ahub)
437 		return -ENODEV;
438 
439 	/*
440 	 * The AHUB hosts a register bus: the "configlink". For this to
441 	 * operate correctly, all devices on this bus must be out of reset.
442 	 * Ensure that here.
443 	 */
444 	for (i = 0; i < ARRAY_SIZE(configlink_clocks); i++) {
445 		clk = clk_get(&pdev->dev, configlink_clocks[i]);
446 		if (IS_ERR(clk)) {
447 			dev_err(&pdev->dev, "Can't get clock %s\n",
448 				configlink_clocks[i]);
449 			ret = PTR_ERR(clk);
450 			goto err;
451 		}
452 		tegra_periph_reset_deassert(clk);
453 		clk_put(clk);
454 	}
455 
456 	ahub = devm_kzalloc(&pdev->dev, sizeof(struct tegra30_ahub),
457 			    GFP_KERNEL);
458 	if (!ahub) {
459 		dev_err(&pdev->dev, "Can't allocate tegra30_ahub\n");
460 		ret = -ENOMEM;
461 		goto err;
462 	}
463 	dev_set_drvdata(&pdev->dev, ahub);
464 
465 	ahub->dev = &pdev->dev;
466 
467 	ahub->clk_d_audio = clk_get(&pdev->dev, "d_audio");
468 	if (IS_ERR(ahub->clk_d_audio)) {
469 		dev_err(&pdev->dev, "Can't retrieve ahub d_audio clock\n");
470 		ret = PTR_ERR(ahub->clk_d_audio);
471 		goto err;
472 	}
473 
474 	ahub->clk_apbif = clk_get(&pdev->dev, "apbif");
475 	if (IS_ERR(ahub->clk_apbif)) {
476 		dev_err(&pdev->dev, "Can't retrieve ahub apbif clock\n");
477 		ret = PTR_ERR(ahub->clk_apbif);
478 		goto err_clk_put_d_audio;
479 	}
480 
481 	if (of_property_read_u32_array(pdev->dev.of_node,
482 				"nvidia,dma-request-selector",
483 				of_dma, 2) < 0) {
484 		dev_err(&pdev->dev,
485 			"Missing property nvidia,dma-request-selector\n");
486 		ret = -ENODEV;
487 		goto err_clk_put_d_audio;
488 	}
489 	ahub->dma_sel = of_dma[1];
490 
491 	res0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
492 	if (!res0) {
493 		dev_err(&pdev->dev, "No apbif memory resource\n");
494 		ret = -ENODEV;
495 		goto err_clk_put_apbif;
496 	}
497 
498 	region = devm_request_mem_region(&pdev->dev, res0->start,
499 					 resource_size(res0), DRV_NAME);
500 	if (!region) {
501 		dev_err(&pdev->dev, "request region apbif failed\n");
502 		ret = -EBUSY;
503 		goto err_clk_put_apbif;
504 	}
505 	ahub->apbif_addr = res0->start;
506 
507 	regs_apbif = devm_ioremap(&pdev->dev, res0->start,
508 				  resource_size(res0));
509 	if (!regs_apbif) {
510 		dev_err(&pdev->dev, "ioremap apbif failed\n");
511 		ret = -ENOMEM;
512 		goto err_clk_put_apbif;
513 	}
514 
515 	ahub->regmap_apbif = devm_regmap_init_mmio(&pdev->dev, regs_apbif,
516 					&tegra30_ahub_apbif_regmap_config);
517 	if (IS_ERR(ahub->regmap_apbif)) {
518 		dev_err(&pdev->dev, "apbif regmap init failed\n");
519 		ret = PTR_ERR(ahub->regmap_apbif);
520 		goto err_clk_put_apbif;
521 	}
522 	regcache_cache_only(ahub->regmap_apbif, true);
523 
524 	res1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
525 	if (!res1) {
526 		dev_err(&pdev->dev, "No ahub memory resource\n");
527 		ret = -ENODEV;
528 		goto err_clk_put_apbif;
529 	}
530 
531 	region = devm_request_mem_region(&pdev->dev, res1->start,
532 					 resource_size(res1), DRV_NAME);
533 	if (!region) {
534 		dev_err(&pdev->dev, "request region ahub failed\n");
535 		ret = -EBUSY;
536 		goto err_clk_put_apbif;
537 	}
538 
539 	regs_ahub = devm_ioremap(&pdev->dev, res1->start,
540 				 resource_size(res1));
541 	if (!regs_ahub) {
542 		dev_err(&pdev->dev, "ioremap ahub failed\n");
543 		ret = -ENOMEM;
544 		goto err_clk_put_apbif;
545 	}
546 
547 	ahub->regmap_ahub = devm_regmap_init_mmio(&pdev->dev, regs_ahub,
548 					&tegra30_ahub_ahub_regmap_config);
549 	if (IS_ERR(ahub->regmap_ahub)) {
550 		dev_err(&pdev->dev, "ahub regmap init failed\n");
551 		ret = PTR_ERR(ahub->regmap_ahub);
552 		goto err_clk_put_apbif;
553 	}
554 	regcache_cache_only(ahub->regmap_ahub, true);
555 
556 	pm_runtime_enable(&pdev->dev);
557 	if (!pm_runtime_enabled(&pdev->dev)) {
558 		ret = tegra30_ahub_runtime_resume(&pdev->dev);
559 		if (ret)
560 			goto err_pm_disable;
561 	}
562 
563 	of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
564 
565 	return 0;
566 
567 err_pm_disable:
568 	pm_runtime_disable(&pdev->dev);
569 err_clk_put_apbif:
570 	clk_put(ahub->clk_apbif);
571 err_clk_put_d_audio:
572 	clk_put(ahub->clk_d_audio);
573 	ahub = NULL;
574 err:
575 	return ret;
576 }
577 
578 static int tegra30_ahub_remove(struct platform_device *pdev)
579 {
580 	if (!ahub)
581 		return -ENODEV;
582 
583 	pm_runtime_disable(&pdev->dev);
584 	if (!pm_runtime_status_suspended(&pdev->dev))
585 		tegra30_ahub_runtime_suspend(&pdev->dev);
586 
587 	clk_put(ahub->clk_apbif);
588 	clk_put(ahub->clk_d_audio);
589 
590 	ahub = NULL;
591 
592 	return 0;
593 }
594 
595 static const struct of_device_id tegra30_ahub_of_match[] = {
596 	{ .compatible = "nvidia,tegra30-ahub", },
597 	{},
598 };
599 
600 static const struct dev_pm_ops tegra30_ahub_pm_ops = {
601 	SET_RUNTIME_PM_OPS(tegra30_ahub_runtime_suspend,
602 			   tegra30_ahub_runtime_resume, NULL)
603 };
604 
605 static struct platform_driver tegra30_ahub_driver = {
606 	.probe = tegra30_ahub_probe,
607 	.remove = tegra30_ahub_remove,
608 	.driver = {
609 		.name = DRV_NAME,
610 		.owner = THIS_MODULE,
611 		.of_match_table = tegra30_ahub_of_match,
612 		.pm = &tegra30_ahub_pm_ops,
613 	},
614 };
615 module_platform_driver(tegra30_ahub_driver);
616 
617 MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
618 MODULE_DESCRIPTION("Tegra30 AHUB driver");
619 MODULE_LICENSE("GPL v2");
620 MODULE_ALIAS("platform:" DRV_NAME);
621 MODULE_DEVICE_TABLE(of, tegra30_ahub_of_match);
622