xref: /openbmc/linux/sound/arm/pxa2xx-ac97-lib.c (revision fb574682)
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 
21 #include <sound/pxa2xx-lib.h>
22 
23 #include <mach/irqs.h>
24 #include <mach/regs-ac97.h>
25 #include <mach/audio.h>
26 
27 static DEFINE_MUTEX(car_mutex);
28 static DECLARE_WAIT_QUEUE_HEAD(gsr_wq);
29 static volatile long gsr_bits;
30 static struct clk *ac97_clk;
31 static struct clk *ac97conf_clk;
32 static int reset_gpio;
33 
34 extern void pxa27x_configure_ac97reset(int reset_gpio, bool to_gpio);
35 
36 /*
37  * Beware PXA27x bugs:
38  *
39  *   o Slot 12 read from modem space will hang controller.
40  *   o CDONE, SDONE interrupt fails after any slot 12 IO.
41  *
42  * We therefore have an hybrid approach for waiting on SDONE (interrupt or
43  * 1 jiffy timeout if interrupt never comes).
44  */
45 
46 int pxa2xx_ac97_read(int slot, unsigned short reg)
47 {
48 	int val = -ENODEV;
49 	volatile u32 *reg_addr;
50 
51 	if (slot > 0)
52 		return -ENODEV;
53 
54 	mutex_lock(&car_mutex);
55 
56 	/* set up primary or secondary codec space */
57 	if (cpu_is_pxa25x() && reg == AC97_GPIO_STATUS)
58 		reg_addr = slot ? &SMC_REG_BASE : &PMC_REG_BASE;
59 	else
60 		reg_addr = slot ? &SAC_REG_BASE : &PAC_REG_BASE;
61 	reg_addr += (reg >> 1);
62 
63 	/* start read access across the ac97 link */
64 	GSR = GSR_CDONE | GSR_SDONE;
65 	gsr_bits = 0;
66 	val = (*reg_addr & 0xffff);
67 	if (reg == AC97_GPIO_STATUS)
68 		goto out;
69 	if (wait_event_timeout(gsr_wq, (GSR | gsr_bits) & GSR_SDONE, 1) <= 0 &&
70 	    !((GSR | gsr_bits) & GSR_SDONE)) {
71 		printk(KERN_ERR "%s: read error (ac97_reg=%d GSR=%#lx)\n",
72 				__func__, reg, GSR | gsr_bits);
73 		val = -ETIMEDOUT;
74 		goto out;
75 	}
76 
77 	/* valid data now */
78 	GSR = GSR_CDONE | GSR_SDONE;
79 	gsr_bits = 0;
80 	val = (*reg_addr & 0xffff);
81 	/* but we've just started another cycle... */
82 	wait_event_timeout(gsr_wq, (GSR | gsr_bits) & GSR_SDONE, 1);
83 
84 out:	mutex_unlock(&car_mutex);
85 	return val;
86 }
87 EXPORT_SYMBOL_GPL(pxa2xx_ac97_read);
88 
89 int pxa2xx_ac97_write(int slot, unsigned short reg, unsigned short val)
90 {
91 	volatile u32 *reg_addr;
92 	int ret = 0;
93 
94 	mutex_lock(&car_mutex);
95 
96 	/* set up primary or secondary codec space */
97 	if (cpu_is_pxa25x() && reg == AC97_GPIO_STATUS)
98 		reg_addr = slot ? &SMC_REG_BASE : &PMC_REG_BASE;
99 	else
100 		reg_addr = slot ? &SAC_REG_BASE : &PAC_REG_BASE;
101 	reg_addr += (reg >> 1);
102 
103 	GSR = GSR_CDONE | GSR_SDONE;
104 	gsr_bits = 0;
105 	*reg_addr = val;
106 	if (wait_event_timeout(gsr_wq, (GSR | gsr_bits) & GSR_CDONE, 1) <= 0 &&
107 	    !((GSR | gsr_bits) & GSR_CDONE)) {
108 		printk(KERN_ERR "%s: write error (ac97_reg=%d GSR=%#lx)\n",
109 				__func__, reg, GSR | gsr_bits);
110 		ret = -EIO;
111 	}
112 
113 	mutex_unlock(&car_mutex);
114 	return ret;
115 }
116 EXPORT_SYMBOL_GPL(pxa2xx_ac97_write);
117 
118 #ifdef CONFIG_PXA25x
119 static inline void pxa_ac97_warm_pxa25x(void)
120 {
121 	gsr_bits = 0;
122 
123 	GCR |= GCR_WARM_RST;
124 }
125 
126 static inline void pxa_ac97_cold_pxa25x(void)
127 {
128 	GCR &=  GCR_COLD_RST;  /* clear everything but nCRST */
129 	GCR &= ~GCR_COLD_RST;  /* then assert nCRST */
130 
131 	gsr_bits = 0;
132 
133 	GCR = GCR_COLD_RST;
134 }
135 #endif
136 
137 #ifdef CONFIG_PXA27x
138 static inline void pxa_ac97_warm_pxa27x(void)
139 {
140 	gsr_bits = 0;
141 
142 	/* warm reset broken on Bulverde, so manually keep AC97 reset high */
143 	pxa27x_configure_ac97reset(reset_gpio, true);
144 	udelay(10);
145 	GCR |= GCR_WARM_RST;
146 	pxa27x_configure_ac97reset(reset_gpio, false);
147 	udelay(500);
148 }
149 
150 static inline void pxa_ac97_cold_pxa27x(void)
151 {
152 	GCR &=  GCR_COLD_RST;  /* clear everything but nCRST */
153 	GCR &= ~GCR_COLD_RST;  /* then assert nCRST */
154 
155 	gsr_bits = 0;
156 
157 	/* PXA27x Developers Manual section 13.5.2.2.1 */
158 	clk_prepare_enable(ac97conf_clk);
159 	udelay(5);
160 	clk_disable_unprepare(ac97conf_clk);
161 	GCR = GCR_COLD_RST | GCR_WARM_RST;
162 }
163 #endif
164 
165 #ifdef CONFIG_PXA3xx
166 static inline void pxa_ac97_warm_pxa3xx(void)
167 {
168 	gsr_bits = 0;
169 
170 	/* Can't use interrupts */
171 	GCR |= GCR_WARM_RST;
172 }
173 
174 static inline void pxa_ac97_cold_pxa3xx(void)
175 {
176 	/* Hold CLKBPB for 100us */
177 	GCR = 0;
178 	GCR = GCR_CLKBPB;
179 	udelay(100);
180 	GCR = 0;
181 
182 	GCR &=  GCR_COLD_RST;  /* clear everything but nCRST */
183 	GCR &= ~GCR_COLD_RST;  /* then assert nCRST */
184 
185 	gsr_bits = 0;
186 
187 	/* Can't use interrupts on PXA3xx */
188 	GCR &= ~(GCR_PRIRDY_IEN|GCR_SECRDY_IEN);
189 
190 	GCR = GCR_WARM_RST | GCR_COLD_RST;
191 }
192 #endif
193 
194 bool pxa2xx_ac97_try_warm_reset(void)
195 {
196 	unsigned long gsr;
197 	unsigned int timeout = 100;
198 
199 #ifdef CONFIG_PXA25x
200 	if (cpu_is_pxa25x())
201 		pxa_ac97_warm_pxa25x();
202 	else
203 #endif
204 #ifdef CONFIG_PXA27x
205 	if (cpu_is_pxa27x())
206 		pxa_ac97_warm_pxa27x();
207 	else
208 #endif
209 #ifdef CONFIG_PXA3xx
210 	if (cpu_is_pxa3xx())
211 		pxa_ac97_warm_pxa3xx();
212 	else
213 #endif
214 		snd_BUG();
215 
216 	while (!((GSR | gsr_bits) & (GSR_PCR | GSR_SCR)) && timeout--)
217 		mdelay(1);
218 
219 	gsr = GSR | gsr_bits;
220 	if (!(gsr & (GSR_PCR | GSR_SCR))) {
221 		printk(KERN_INFO "%s: warm reset timeout (GSR=%#lx)\n",
222 				 __func__, gsr);
223 
224 		return false;
225 	}
226 
227 	return true;
228 }
229 EXPORT_SYMBOL_GPL(pxa2xx_ac97_try_warm_reset);
230 
231 bool pxa2xx_ac97_try_cold_reset(void)
232 {
233 	unsigned long gsr;
234 	unsigned int timeout = 1000;
235 
236 #ifdef CONFIG_PXA25x
237 	if (cpu_is_pxa25x())
238 		pxa_ac97_cold_pxa25x();
239 	else
240 #endif
241 #ifdef CONFIG_PXA27x
242 	if (cpu_is_pxa27x())
243 		pxa_ac97_cold_pxa27x();
244 	else
245 #endif
246 #ifdef CONFIG_PXA3xx
247 	if (cpu_is_pxa3xx())
248 		pxa_ac97_cold_pxa3xx();
249 	else
250 #endif
251 		snd_BUG();
252 
253 	while (!((GSR | gsr_bits) & (GSR_PCR | GSR_SCR)) && timeout--)
254 		mdelay(1);
255 
256 	gsr = GSR | gsr_bits;
257 	if (!(gsr & (GSR_PCR | GSR_SCR))) {
258 		printk(KERN_INFO "%s: cold reset timeout (GSR=%#lx)\n",
259 				 __func__, gsr);
260 
261 		return false;
262 	}
263 
264 	return true;
265 }
266 EXPORT_SYMBOL_GPL(pxa2xx_ac97_try_cold_reset);
267 
268 
269 void pxa2xx_ac97_finish_reset(void)
270 {
271 	GCR &= ~(GCR_PRIRDY_IEN|GCR_SECRDY_IEN);
272 	GCR |= GCR_SDONE_IE|GCR_CDONE_IE;
273 }
274 EXPORT_SYMBOL_GPL(pxa2xx_ac97_finish_reset);
275 
276 static irqreturn_t pxa2xx_ac97_irq(int irq, void *dev_id)
277 {
278 	long status;
279 
280 	status = GSR;
281 	if (status) {
282 		GSR = status;
283 		gsr_bits |= status;
284 		wake_up(&gsr_wq);
285 
286 		/* Although we don't use those we still need to clear them
287 		   since they tend to spuriously trigger when MMC is used
288 		   (hardware bug? go figure)... */
289 		if (cpu_is_pxa27x()) {
290 			MISR = MISR_EOC;
291 			PISR = PISR_EOC;
292 			MCSR = MCSR_EOC;
293 		}
294 
295 		return IRQ_HANDLED;
296 	}
297 
298 	return IRQ_NONE;
299 }
300 
301 #ifdef CONFIG_PM
302 int pxa2xx_ac97_hw_suspend(void)
303 {
304 	GCR |= GCR_ACLINK_OFF;
305 	clk_disable_unprepare(ac97_clk);
306 	return 0;
307 }
308 EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_suspend);
309 
310 int pxa2xx_ac97_hw_resume(void)
311 {
312 	clk_prepare_enable(ac97_clk);
313 	return 0;
314 }
315 EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_resume);
316 #endif
317 
318 int pxa2xx_ac97_hw_probe(struct platform_device *dev)
319 {
320 	int ret;
321 	pxa2xx_audio_ops_t *pdata = dev->dev.platform_data;
322 
323 	if (pdata) {
324 		switch (pdata->reset_gpio) {
325 		case 95:
326 		case 113:
327 			reset_gpio = pdata->reset_gpio;
328 			break;
329 		case 0:
330 			reset_gpio = 113;
331 			break;
332 		case -1:
333 			break;
334 		default:
335 			dev_err(&dev->dev, "Invalid reset GPIO %d\n",
336 				pdata->reset_gpio);
337 		}
338 	} else if (!pdata && dev->dev.of_node) {
339 		pdata = devm_kzalloc(&dev->dev, sizeof(*pdata), GFP_KERNEL);
340 		if (!pdata)
341 			return -ENOMEM;
342 		pdata->reset_gpio = of_get_named_gpio(dev->dev.of_node,
343 						      "reset-gpios", 0);
344 		if (pdata->reset_gpio == -ENOENT)
345 			pdata->reset_gpio = -1;
346 		else if (pdata->reset_gpio < 0)
347 			return pdata->reset_gpio;
348 		reset_gpio = pdata->reset_gpio;
349 	} else {
350 		if (cpu_is_pxa27x())
351 			reset_gpio = 113;
352 	}
353 
354 	if (cpu_is_pxa27x()) {
355 		/*
356 		 * This gpio is needed for a work-around to a bug in the ac97
357 		 * controller during warm reset.  The direction and level is set
358 		 * here so that it is an output driven high when switching from
359 		 * AC97_nRESET alt function to generic gpio.
360 		 */
361 		ret = gpio_request_one(reset_gpio, GPIOF_OUT_INIT_HIGH,
362 				       "pxa27x ac97 reset");
363 		if (ret < 0) {
364 			pr_err("%s: gpio_request_one() failed: %d\n",
365 			       __func__, ret);
366 			goto err_conf;
367 		}
368 		pxa27x_configure_ac97reset(reset_gpio, false);
369 
370 		ac97conf_clk = clk_get(&dev->dev, "AC97CONFCLK");
371 		if (IS_ERR(ac97conf_clk)) {
372 			ret = PTR_ERR(ac97conf_clk);
373 			ac97conf_clk = NULL;
374 			goto err_conf;
375 		}
376 	}
377 
378 	ac97_clk = clk_get(&dev->dev, "AC97CLK");
379 	if (IS_ERR(ac97_clk)) {
380 		ret = PTR_ERR(ac97_clk);
381 		ac97_clk = NULL;
382 		goto err_clk;
383 	}
384 
385 	ret = clk_prepare_enable(ac97_clk);
386 	if (ret)
387 		goto err_clk2;
388 
389 	ret = request_irq(IRQ_AC97, pxa2xx_ac97_irq, 0, "AC97", NULL);
390 	if (ret < 0)
391 		goto err_irq;
392 
393 	return 0;
394 
395 err_irq:
396 	GCR |= GCR_ACLINK_OFF;
397 err_clk2:
398 	clk_put(ac97_clk);
399 	ac97_clk = NULL;
400 err_clk:
401 	if (ac97conf_clk) {
402 		clk_put(ac97conf_clk);
403 		ac97conf_clk = NULL;
404 	}
405 err_conf:
406 	return ret;
407 }
408 EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_probe);
409 
410 void pxa2xx_ac97_hw_remove(struct platform_device *dev)
411 {
412 	if (cpu_is_pxa27x())
413 		gpio_free(reset_gpio);
414 	GCR |= GCR_ACLINK_OFF;
415 	free_irq(IRQ_AC97, NULL);
416 	if (ac97conf_clk) {
417 		clk_put(ac97conf_clk);
418 		ac97conf_clk = NULL;
419 	}
420 	clk_disable_unprepare(ac97_clk);
421 	clk_put(ac97_clk);
422 	ac97_clk = NULL;
423 }
424 EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_remove);
425 
426 MODULE_AUTHOR("Nicolas Pitre");
427 MODULE_DESCRIPTION("Intel/Marvell PXA sound library");
428 MODULE_LICENSE("GPL");
429 
430