xref: /openbmc/linux/sound/arm/pxa2xx-ac97-lib.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Based on sound/arm/pxa2xx-ac97.c and sound/soc/pxa/pxa2xx-ac97.c
4  * which contain:
5  *
6  * Author:	Nicolas Pitre
7  * Created:	Dec 02, 2004
8  * Copyright:	MontaVista Software Inc.
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/platform_device.h>
13 #include <linux/interrupt.h>
14 #include <linux/clk.h>
15 #include <linux/delay.h>
16 #include <linux/module.h>
17 #include <linux/io.h>
18 #include <linux/gpio.h>
19 #include <linux/of_gpio.h>
20 #include <linux/soc/pxa/cpu.h>
21 
22 #include <sound/pxa2xx-lib.h>
23 
24 #include <linux/platform_data/asoc-pxa.h>
25 
26 #include "pxa2xx-ac97-regs.h"
27 
28 static DEFINE_MUTEX(car_mutex);
29 static DECLARE_WAIT_QUEUE_HEAD(gsr_wq);
30 static volatile long gsr_bits;
31 static struct clk *ac97_clk;
32 static struct clk *ac97conf_clk;
33 static int reset_gpio;
34 static void __iomem *ac97_reg_base;
35 
36 extern void pxa27x_configure_ac97reset(int reset_gpio, bool to_gpio);
37 
38 /*
39  * Beware PXA27x bugs:
40  *
41  *   o Slot 12 read from modem space will hang controller.
42  *   o CDONE, SDONE interrupt fails after any slot 12 IO.
43  *
44  * We therefore have an hybrid approach for waiting on SDONE (interrupt or
45  * 1 jiffy timeout if interrupt never comes).
46  */
47 
48 int pxa2xx_ac97_read(int slot, unsigned short reg)
49 {
50 	int val = -ENODEV;
51 	u32 __iomem *reg_addr;
52 
53 	if (slot > 0)
54 		return -ENODEV;
55 
56 	mutex_lock(&car_mutex);
57 
58 	/* set up primary or secondary codec space */
59 	if (cpu_is_pxa25x() && reg == AC97_GPIO_STATUS)
60 		reg_addr = ac97_reg_base +
61 			   (slot ? SMC_REG_BASE : PMC_REG_BASE);
62 	else
63 		reg_addr = ac97_reg_base +
64 			   (slot ? SAC_REG_BASE : PAC_REG_BASE);
65 	reg_addr += (reg >> 1);
66 
67 	/* start read access across the ac97 link */
68 	writel(GSR_CDONE | GSR_SDONE, ac97_reg_base + GSR);
69 	gsr_bits = 0;
70 	val = (readl(reg_addr) & 0xffff);
71 	if (reg == AC97_GPIO_STATUS)
72 		goto out;
73 	if (wait_event_timeout(gsr_wq, (readl(ac97_reg_base + GSR) | gsr_bits) & GSR_SDONE, 1) <= 0 &&
74 	    !((readl(ac97_reg_base + GSR) | gsr_bits) & GSR_SDONE)) {
75 		printk(KERN_ERR "%s: read error (ac97_reg=%d GSR=%#lx)\n",
76 				__func__, reg, readl(ac97_reg_base + GSR) | gsr_bits);
77 		val = -ETIMEDOUT;
78 		goto out;
79 	}
80 
81 	/* valid data now */
82 	writel(GSR_CDONE | GSR_SDONE, ac97_reg_base + GSR);
83 	gsr_bits = 0;
84 	val = (readl(reg_addr) & 0xffff);
85 	/* but we've just started another cycle... */
86 	wait_event_timeout(gsr_wq, (readl(ac97_reg_base + GSR) | gsr_bits) & GSR_SDONE, 1);
87 
88 out:	mutex_unlock(&car_mutex);
89 	return val;
90 }
91 EXPORT_SYMBOL_GPL(pxa2xx_ac97_read);
92 
93 int pxa2xx_ac97_write(int slot, unsigned short reg, unsigned short val)
94 {
95 	u32 __iomem *reg_addr;
96 	int ret = 0;
97 
98 	mutex_lock(&car_mutex);
99 
100 	/* set up primary or secondary codec space */
101 	if (cpu_is_pxa25x() && reg == AC97_GPIO_STATUS)
102 		reg_addr = ac97_reg_base +
103 			   (slot ? SMC_REG_BASE : PMC_REG_BASE);
104 	else
105 		reg_addr = ac97_reg_base +
106 			   (slot ? SAC_REG_BASE : PAC_REG_BASE);
107 	reg_addr += (reg >> 1);
108 
109 	writel(GSR_CDONE | GSR_SDONE, ac97_reg_base + GSR);
110 	gsr_bits = 0;
111 	writel(val, reg_addr);
112 	if (wait_event_timeout(gsr_wq, (readl(ac97_reg_base + GSR) | gsr_bits) & GSR_CDONE, 1) <= 0 &&
113 	    !((readl(ac97_reg_base + GSR) | gsr_bits) & GSR_CDONE)) {
114 		printk(KERN_ERR "%s: write error (ac97_reg=%d GSR=%#lx)\n",
115 				__func__, reg, readl(ac97_reg_base + GSR) | gsr_bits);
116 		ret = -EIO;
117 	}
118 
119 	mutex_unlock(&car_mutex);
120 	return ret;
121 }
122 EXPORT_SYMBOL_GPL(pxa2xx_ac97_write);
123 
124 #ifdef CONFIG_PXA25x
125 static inline void pxa_ac97_warm_pxa25x(void)
126 {
127 	gsr_bits = 0;
128 
129 	writel(readl(ac97_reg_base + GCR) | (GCR_WARM_RST), ac97_reg_base + GCR);
130 }
131 
132 static inline void pxa_ac97_cold_pxa25x(void)
133 {
134 	writel(readl(ac97_reg_base + GCR) & ( GCR_COLD_RST), ac97_reg_base + GCR);  /* clear everything but nCRST */
135 	writel(readl(ac97_reg_base + GCR) & (~GCR_COLD_RST), ac97_reg_base + GCR);  /* then assert nCRST */
136 
137 	gsr_bits = 0;
138 
139 	writel(GCR_COLD_RST, ac97_reg_base + GCR);
140 }
141 #endif
142 
143 #ifdef CONFIG_PXA27x
144 static inline void pxa_ac97_warm_pxa27x(void)
145 {
146 	gsr_bits = 0;
147 
148 	/* warm reset broken on Bulverde, so manually keep AC97 reset high */
149 	pxa27x_configure_ac97reset(reset_gpio, true);
150 	udelay(10);
151 	writel(readl(ac97_reg_base + GCR) | (GCR_WARM_RST), ac97_reg_base + GCR);
152 	pxa27x_configure_ac97reset(reset_gpio, false);
153 	udelay(500);
154 }
155 
156 static inline void pxa_ac97_cold_pxa27x(void)
157 {
158 	writel(readl(ac97_reg_base + GCR) & ( GCR_COLD_RST), ac97_reg_base + GCR);  /* clear everything but nCRST */
159 	writel(readl(ac97_reg_base + GCR) & (~GCR_COLD_RST), ac97_reg_base + GCR);  /* then assert nCRST */
160 
161 	gsr_bits = 0;
162 
163 	/* PXA27x Developers Manual section 13.5.2.2.1 */
164 	clk_prepare_enable(ac97conf_clk);
165 	udelay(5);
166 	clk_disable_unprepare(ac97conf_clk);
167 	writel(GCR_COLD_RST | GCR_WARM_RST, ac97_reg_base + GCR);
168 }
169 #endif
170 
171 #ifdef CONFIG_PXA3xx
172 static inline void pxa_ac97_warm_pxa3xx(void)
173 {
174 	gsr_bits = 0;
175 
176 	/* Can't use interrupts */
177 	writel(readl(ac97_reg_base + GCR) | (GCR_WARM_RST), ac97_reg_base + GCR);
178 }
179 
180 static inline void pxa_ac97_cold_pxa3xx(void)
181 {
182 	/* Hold CLKBPB for 100us */
183 	writel(0, ac97_reg_base + GCR);
184 	writel(GCR_CLKBPB, ac97_reg_base + GCR);
185 	udelay(100);
186 	writel(0, ac97_reg_base + GCR);
187 
188 	writel(readl(ac97_reg_base + GCR) & ( GCR_COLD_RST), ac97_reg_base + GCR);  /* clear everything but nCRST */
189 	writel(readl(ac97_reg_base + GCR) & (~GCR_COLD_RST), ac97_reg_base + GCR);  /* then assert nCRST */
190 
191 	gsr_bits = 0;
192 
193 	/* Can't use interrupts on PXA3xx */
194 	writel(readl(ac97_reg_base + GCR) & (~(GCR_PRIRDY_IEN|GCR_SECRDY_IEN)), ac97_reg_base + GCR);
195 
196 	writel(GCR_WARM_RST | GCR_COLD_RST, ac97_reg_base + GCR);
197 }
198 #endif
199 
200 bool pxa2xx_ac97_try_warm_reset(void)
201 {
202 	unsigned long gsr;
203 	unsigned int timeout = 100;
204 
205 #ifdef CONFIG_PXA25x
206 	if (cpu_is_pxa25x())
207 		pxa_ac97_warm_pxa25x();
208 	else
209 #endif
210 #ifdef CONFIG_PXA27x
211 	if (cpu_is_pxa27x())
212 		pxa_ac97_warm_pxa27x();
213 	else
214 #endif
215 #ifdef CONFIG_PXA3xx
216 	if (cpu_is_pxa3xx())
217 		pxa_ac97_warm_pxa3xx();
218 	else
219 #endif
220 		snd_BUG();
221 
222 	while (!((readl(ac97_reg_base + GSR) | gsr_bits) & (GSR_PCR | GSR_SCR)) && timeout--)
223 		mdelay(1);
224 
225 	gsr = readl(ac97_reg_base + GSR) | gsr_bits;
226 	if (!(gsr & (GSR_PCR | GSR_SCR))) {
227 		printk(KERN_INFO "%s: warm reset timeout (GSR=%#lx)\n",
228 				 __func__, gsr);
229 
230 		return false;
231 	}
232 
233 	return true;
234 }
235 EXPORT_SYMBOL_GPL(pxa2xx_ac97_try_warm_reset);
236 
237 bool pxa2xx_ac97_try_cold_reset(void)
238 {
239 	unsigned long gsr;
240 	unsigned int timeout = 1000;
241 
242 #ifdef CONFIG_PXA25x
243 	if (cpu_is_pxa25x())
244 		pxa_ac97_cold_pxa25x();
245 	else
246 #endif
247 #ifdef CONFIG_PXA27x
248 	if (cpu_is_pxa27x())
249 		pxa_ac97_cold_pxa27x();
250 	else
251 #endif
252 #ifdef CONFIG_PXA3xx
253 	if (cpu_is_pxa3xx())
254 		pxa_ac97_cold_pxa3xx();
255 	else
256 #endif
257 		snd_BUG();
258 
259 	while (!((readl(ac97_reg_base + GSR) | gsr_bits) & (GSR_PCR | GSR_SCR)) && timeout--)
260 		mdelay(1);
261 
262 	gsr = readl(ac97_reg_base + GSR) | gsr_bits;
263 	if (!(gsr & (GSR_PCR | GSR_SCR))) {
264 		printk(KERN_INFO "%s: cold reset timeout (GSR=%#lx)\n",
265 				 __func__, gsr);
266 
267 		return false;
268 	}
269 
270 	return true;
271 }
272 EXPORT_SYMBOL_GPL(pxa2xx_ac97_try_cold_reset);
273 
274 
275 void pxa2xx_ac97_finish_reset(void)
276 {
277 	u32 gcr = readl(ac97_reg_base + GCR);
278 	gcr &= ~(GCR_PRIRDY_IEN|GCR_SECRDY_IEN);
279 	gcr |= GCR_SDONE_IE|GCR_CDONE_IE;
280 	writel(gcr, ac97_reg_base + GCR);
281 }
282 EXPORT_SYMBOL_GPL(pxa2xx_ac97_finish_reset);
283 
284 static irqreturn_t pxa2xx_ac97_irq(int irq, void *dev_id)
285 {
286 	long status;
287 
288 	status = readl(ac97_reg_base + GSR);
289 	if (status) {
290 		writel(status, ac97_reg_base + GSR);
291 		gsr_bits |= status;
292 		wake_up(&gsr_wq);
293 
294 		/* Although we don't use those we still need to clear them
295 		   since they tend to spuriously trigger when MMC is used
296 		   (hardware bug? go figure)... */
297 		if (cpu_is_pxa27x()) {
298 			writel(MISR_EOC, ac97_reg_base + MISR);
299 			writel(PISR_EOC, ac97_reg_base + PISR);
300 			writel(MCSR_EOC, ac97_reg_base + MCSR);
301 		}
302 
303 		return IRQ_HANDLED;
304 	}
305 
306 	return IRQ_NONE;
307 }
308 
309 #ifdef CONFIG_PM
310 int pxa2xx_ac97_hw_suspend(void)
311 {
312 	writel(readl(ac97_reg_base + GCR) | (GCR_ACLINK_OFF), ac97_reg_base + GCR);
313 	clk_disable_unprepare(ac97_clk);
314 	return 0;
315 }
316 EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_suspend);
317 
318 int pxa2xx_ac97_hw_resume(void)
319 {
320 	clk_prepare_enable(ac97_clk);
321 	return 0;
322 }
323 EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_resume);
324 #endif
325 
326 int pxa2xx_ac97_hw_probe(struct platform_device *dev)
327 {
328 	int ret;
329 	int irq;
330 	pxa2xx_audio_ops_t *pdata = dev->dev.platform_data;
331 
332 	ac97_reg_base = devm_platform_ioremap_resource(dev, 0);
333 	if (IS_ERR(ac97_reg_base)) {
334 		dev_err(&dev->dev, "Missing MMIO resource\n");
335 		return PTR_ERR(ac97_reg_base);
336 	}
337 
338 	if (pdata) {
339 		switch (pdata->reset_gpio) {
340 		case 95:
341 		case 113:
342 			reset_gpio = pdata->reset_gpio;
343 			break;
344 		case 0:
345 			reset_gpio = 113;
346 			break;
347 		case -1:
348 			break;
349 		default:
350 			dev_err(&dev->dev, "Invalid reset GPIO %d\n",
351 				pdata->reset_gpio);
352 		}
353 	} else if (!pdata && dev->dev.of_node) {
354 		pdata = devm_kzalloc(&dev->dev, sizeof(*pdata), GFP_KERNEL);
355 		if (!pdata)
356 			return -ENOMEM;
357 		pdata->reset_gpio = of_get_named_gpio(dev->dev.of_node,
358 						      "reset-gpios", 0);
359 		if (pdata->reset_gpio == -ENOENT)
360 			pdata->reset_gpio = -1;
361 		else if (pdata->reset_gpio < 0)
362 			return pdata->reset_gpio;
363 		reset_gpio = pdata->reset_gpio;
364 	} else {
365 		if (cpu_is_pxa27x())
366 			reset_gpio = 113;
367 	}
368 
369 	if (cpu_is_pxa27x()) {
370 		/*
371 		 * This gpio is needed for a work-around to a bug in the ac97
372 		 * controller during warm reset.  The direction and level is set
373 		 * here so that it is an output driven high when switching from
374 		 * AC97_nRESET alt function to generic gpio.
375 		 */
376 		ret = gpio_request_one(reset_gpio, GPIOF_OUT_INIT_HIGH,
377 				       "pxa27x ac97 reset");
378 		if (ret < 0) {
379 			pr_err("%s: gpio_request_one() failed: %d\n",
380 			       __func__, ret);
381 			goto err_conf;
382 		}
383 		pxa27x_configure_ac97reset(reset_gpio, false);
384 
385 		ac97conf_clk = clk_get(&dev->dev, "AC97CONFCLK");
386 		if (IS_ERR(ac97conf_clk)) {
387 			ret = PTR_ERR(ac97conf_clk);
388 			ac97conf_clk = NULL;
389 			goto err_conf;
390 		}
391 	}
392 
393 	ac97_clk = clk_get(&dev->dev, "AC97CLK");
394 	if (IS_ERR(ac97_clk)) {
395 		ret = PTR_ERR(ac97_clk);
396 		ac97_clk = NULL;
397 		goto err_clk;
398 	}
399 
400 	ret = clk_prepare_enable(ac97_clk);
401 	if (ret)
402 		goto err_clk2;
403 
404 	irq = platform_get_irq(dev, 0);
405 	if (!irq)
406 		goto err_irq;
407 
408 	ret = request_irq(irq, pxa2xx_ac97_irq, 0, "AC97", NULL);
409 	if (ret < 0)
410 		goto err_irq;
411 
412 	return 0;
413 
414 err_irq:
415 	writel(readl(ac97_reg_base + GCR) | (GCR_ACLINK_OFF), ac97_reg_base + GCR);
416 err_clk2:
417 	clk_put(ac97_clk);
418 	ac97_clk = NULL;
419 err_clk:
420 	if (ac97conf_clk) {
421 		clk_put(ac97conf_clk);
422 		ac97conf_clk = NULL;
423 	}
424 err_conf:
425 	return ret;
426 }
427 EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_probe);
428 
429 void pxa2xx_ac97_hw_remove(struct platform_device *dev)
430 {
431 	if (cpu_is_pxa27x())
432 		gpio_free(reset_gpio);
433 	writel(readl(ac97_reg_base + GCR) | (GCR_ACLINK_OFF), ac97_reg_base + GCR);
434 	free_irq(platform_get_irq(dev, 0), NULL);
435 	if (ac97conf_clk) {
436 		clk_put(ac97conf_clk);
437 		ac97conf_clk = NULL;
438 	}
439 	clk_disable_unprepare(ac97_clk);
440 	clk_put(ac97_clk);
441 	ac97_clk = NULL;
442 }
443 EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_remove);
444 
445 u32 pxa2xx_ac97_read_modr(void)
446 {
447 	if (!ac97_reg_base)
448 		return 0;
449 
450 	return readl(ac97_reg_base + MODR);
451 }
452 EXPORT_SYMBOL_GPL(pxa2xx_ac97_read_modr);
453 
454 u32 pxa2xx_ac97_read_misr(void)
455 {
456 	if (!ac97_reg_base)
457 		return 0;
458 
459 	return readl(ac97_reg_base + MISR);
460 }
461 EXPORT_SYMBOL_GPL(pxa2xx_ac97_read_misr);
462 
463 MODULE_AUTHOR("Nicolas Pitre");
464 MODULE_DESCRIPTION("Intel/Marvell PXA sound library");
465 MODULE_LICENSE("GPL");
466 
467