xref: /linux/drivers/hsi/controllers/omap_ssi_port.c (revision 69bfec7548f4c1595bac0e3ddfc0458a5af31f4c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* OMAP SSI port driver.
3  *
4  * Copyright (C) 2010 Nokia Corporation. All rights reserved.
5  * Copyright (C) 2014 Sebastian Reichel <sre@kernel.org>
6  *
7  * Contact: Carlos Chinea <carlos.chinea@nokia.com>
8  */
9 
10 #include <linux/mod_devicetable.h>
11 #include <linux/platform_device.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/pm_runtime.h>
14 #include <linux/delay.h>
15 
16 #include <linux/gpio/consumer.h>
17 #include <linux/pinctrl/consumer.h>
18 #include <linux/debugfs.h>
19 
20 #include "omap_ssi_regs.h"
21 #include "omap_ssi.h"
22 
23 static inline int hsi_dummy_msg(struct hsi_msg *msg __maybe_unused)
24 {
25 	return 0;
26 }
27 
28 static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused)
29 {
30 	return 0;
31 }
32 
33 static inline unsigned int ssi_wakein(struct hsi_port *port)
34 {
35 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
36 	return gpiod_get_value(omap_port->wake_gpio);
37 }
38 
39 #ifdef CONFIG_DEBUG_FS
40 static void ssi_debug_remove_port(struct hsi_port *port)
41 {
42 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
43 
44 	debugfs_remove_recursive(omap_port->dir);
45 }
46 
47 static int ssi_port_regs_show(struct seq_file *m, void *p __maybe_unused)
48 {
49 	struct hsi_port *port = m->private;
50 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
51 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
52 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
53 	void __iomem	*base = omap_ssi->sys;
54 	unsigned int ch;
55 
56 	pm_runtime_get_sync(omap_port->pdev);
57 	if (omap_port->wake_irq > 0)
58 		seq_printf(m, "CAWAKE\t\t: %d\n", ssi_wakein(port));
59 	seq_printf(m, "WAKE\t\t: 0x%08x\n",
60 				readl(base + SSI_WAKE_REG(port->num)));
61 	seq_printf(m, "MPU_ENABLE_IRQ%d\t: 0x%08x\n", 0,
62 			readl(base + SSI_MPU_ENABLE_REG(port->num, 0)));
63 	seq_printf(m, "MPU_STATUS_IRQ%d\t: 0x%08x\n", 0,
64 			readl(base + SSI_MPU_STATUS_REG(port->num, 0)));
65 	/* SST */
66 	base = omap_port->sst_base;
67 	seq_puts(m, "\nSST\n===\n");
68 	seq_printf(m, "ID SST\t\t: 0x%08x\n",
69 				readl(base + SSI_SST_ID_REG));
70 	seq_printf(m, "MODE\t\t: 0x%08x\n",
71 				readl(base + SSI_SST_MODE_REG));
72 	seq_printf(m, "FRAMESIZE\t: 0x%08x\n",
73 				readl(base + SSI_SST_FRAMESIZE_REG));
74 	seq_printf(m, "DIVISOR\t\t: 0x%08x\n",
75 				readl(base + SSI_SST_DIVISOR_REG));
76 	seq_printf(m, "CHANNELS\t: 0x%08x\n",
77 				readl(base + SSI_SST_CHANNELS_REG));
78 	seq_printf(m, "ARBMODE\t\t: 0x%08x\n",
79 				readl(base + SSI_SST_ARBMODE_REG));
80 	seq_printf(m, "TXSTATE\t\t: 0x%08x\n",
81 				readl(base + SSI_SST_TXSTATE_REG));
82 	seq_printf(m, "BUFSTATE\t: 0x%08x\n",
83 				readl(base + SSI_SST_BUFSTATE_REG));
84 	seq_printf(m, "BREAK\t\t: 0x%08x\n",
85 				readl(base + SSI_SST_BREAK_REG));
86 	for (ch = 0; ch < omap_port->channels; ch++) {
87 		seq_printf(m, "BUFFER_CH%d\t: 0x%08x\n", ch,
88 				readl(base + SSI_SST_BUFFER_CH_REG(ch)));
89 	}
90 	/* SSR */
91 	base = omap_port->ssr_base;
92 	seq_puts(m, "\nSSR\n===\n");
93 	seq_printf(m, "ID SSR\t\t: 0x%08x\n",
94 				readl(base + SSI_SSR_ID_REG));
95 	seq_printf(m, "MODE\t\t: 0x%08x\n",
96 				readl(base + SSI_SSR_MODE_REG));
97 	seq_printf(m, "FRAMESIZE\t: 0x%08x\n",
98 				readl(base + SSI_SSR_FRAMESIZE_REG));
99 	seq_printf(m, "CHANNELS\t: 0x%08x\n",
100 				readl(base + SSI_SSR_CHANNELS_REG));
101 	seq_printf(m, "TIMEOUT\t\t: 0x%08x\n",
102 				readl(base + SSI_SSR_TIMEOUT_REG));
103 	seq_printf(m, "RXSTATE\t\t: 0x%08x\n",
104 				readl(base + SSI_SSR_RXSTATE_REG));
105 	seq_printf(m, "BUFSTATE\t: 0x%08x\n",
106 				readl(base + SSI_SSR_BUFSTATE_REG));
107 	seq_printf(m, "BREAK\t\t: 0x%08x\n",
108 				readl(base + SSI_SSR_BREAK_REG));
109 	seq_printf(m, "ERROR\t\t: 0x%08x\n",
110 				readl(base + SSI_SSR_ERROR_REG));
111 	seq_printf(m, "ERRORACK\t: 0x%08x\n",
112 				readl(base + SSI_SSR_ERRORACK_REG));
113 	for (ch = 0; ch < omap_port->channels; ch++) {
114 		seq_printf(m, "BUFFER_CH%d\t: 0x%08x\n", ch,
115 				readl(base + SSI_SSR_BUFFER_CH_REG(ch)));
116 	}
117 	pm_runtime_put_autosuspend(omap_port->pdev);
118 
119 	return 0;
120 }
121 
122 DEFINE_SHOW_ATTRIBUTE(ssi_port_regs);
123 
124 static int ssi_div_get(void *data, u64 *val)
125 {
126 	struct hsi_port *port = data;
127 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
128 
129 	pm_runtime_get_sync(omap_port->pdev);
130 	*val = readl(omap_port->sst_base + SSI_SST_DIVISOR_REG);
131 	pm_runtime_put_autosuspend(omap_port->pdev);
132 
133 	return 0;
134 }
135 
136 static int ssi_div_set(void *data, u64 val)
137 {
138 	struct hsi_port *port = data;
139 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
140 
141 	if (val > 127)
142 		return -EINVAL;
143 
144 	pm_runtime_get_sync(omap_port->pdev);
145 	writel(val, omap_port->sst_base + SSI_SST_DIVISOR_REG);
146 	omap_port->sst.divisor = val;
147 	pm_runtime_put_autosuspend(omap_port->pdev);
148 
149 	return 0;
150 }
151 
152 DEFINE_DEBUGFS_ATTRIBUTE(ssi_sst_div_fops, ssi_div_get, ssi_div_set, "%llu\n");
153 
154 static int ssi_debug_add_port(struct omap_ssi_port *omap_port,
155 				     struct dentry *dir)
156 {
157 	struct hsi_port *port = to_hsi_port(omap_port->dev);
158 
159 	dir = debugfs_create_dir(dev_name(omap_port->dev), dir);
160 	if (!dir)
161 		return -ENOMEM;
162 	omap_port->dir = dir;
163 	debugfs_create_file("regs", S_IRUGO, dir, port, &ssi_port_regs_fops);
164 	dir = debugfs_create_dir("sst", dir);
165 	if (!dir)
166 		return -ENOMEM;
167 	debugfs_create_file_unsafe("divisor", 0644, dir, port,
168 				   &ssi_sst_div_fops);
169 
170 	return 0;
171 }
172 #endif
173 
174 static void ssi_process_errqueue(struct work_struct *work)
175 {
176 	struct omap_ssi_port *omap_port;
177 	struct list_head *head, *tmp;
178 	struct hsi_msg *msg;
179 
180 	omap_port = container_of(work, struct omap_ssi_port, errqueue_work.work);
181 
182 	list_for_each_safe(head, tmp, &omap_port->errqueue) {
183 		msg = list_entry(head, struct hsi_msg, link);
184 		msg->complete(msg);
185 		list_del(head);
186 	}
187 }
188 
189 static int ssi_claim_lch(struct hsi_msg *msg)
190 {
191 
192 	struct hsi_port *port = hsi_get_port(msg->cl);
193 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
194 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
195 	int lch;
196 
197 	for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++)
198 		if (!omap_ssi->gdd_trn[lch].msg) {
199 			omap_ssi->gdd_trn[lch].msg = msg;
200 			omap_ssi->gdd_trn[lch].sg = msg->sgt.sgl;
201 			return lch;
202 		}
203 
204 	return -EBUSY;
205 }
206 
207 static int ssi_start_dma(struct hsi_msg *msg, int lch)
208 {
209 	struct hsi_port *port = hsi_get_port(msg->cl);
210 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
211 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
212 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
213 	void __iomem *gdd = omap_ssi->gdd;
214 	int err;
215 	u16 csdp;
216 	u16 ccr;
217 	u32 s_addr;
218 	u32 d_addr;
219 	u32 tmp;
220 
221 	/* Hold clocks during the transfer */
222 	pm_runtime_get(omap_port->pdev);
223 
224 	if (!pm_runtime_active(omap_port->pdev)) {
225 		dev_warn(&port->device, "ssi_start_dma called without runtime PM!\n");
226 		pm_runtime_put_autosuspend(omap_port->pdev);
227 		return -EREMOTEIO;
228 	}
229 
230 	if (msg->ttype == HSI_MSG_READ) {
231 		err = dma_map_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents,
232 							DMA_FROM_DEVICE);
233 		if (!err) {
234 			dev_dbg(&ssi->device, "DMA map SG failed !\n");
235 			pm_runtime_put_autosuspend(omap_port->pdev);
236 			return -EIO;
237 		}
238 		csdp = SSI_DST_BURST_4x32_BIT | SSI_DST_MEMORY_PORT |
239 			SSI_SRC_SINGLE_ACCESS0 | SSI_SRC_PERIPHERAL_PORT |
240 			SSI_DATA_TYPE_S32;
241 		ccr = msg->channel + 0x10 + (port->num * 8); /* Sync */
242 		ccr |= SSI_DST_AMODE_POSTINC | SSI_SRC_AMODE_CONST |
243 			SSI_CCR_ENABLE;
244 		s_addr = omap_port->ssr_dma +
245 					SSI_SSR_BUFFER_CH_REG(msg->channel);
246 		d_addr = sg_dma_address(msg->sgt.sgl);
247 	} else {
248 		err = dma_map_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents,
249 							DMA_TO_DEVICE);
250 		if (!err) {
251 			dev_dbg(&ssi->device, "DMA map SG failed !\n");
252 			pm_runtime_put_autosuspend(omap_port->pdev);
253 			return -EIO;
254 		}
255 		csdp = SSI_SRC_BURST_4x32_BIT | SSI_SRC_MEMORY_PORT |
256 			SSI_DST_SINGLE_ACCESS0 | SSI_DST_PERIPHERAL_PORT |
257 			SSI_DATA_TYPE_S32;
258 		ccr = (msg->channel + 1 + (port->num * 8)) & 0xf; /* Sync */
259 		ccr |= SSI_SRC_AMODE_POSTINC | SSI_DST_AMODE_CONST |
260 			SSI_CCR_ENABLE;
261 		s_addr = sg_dma_address(msg->sgt.sgl);
262 		d_addr = omap_port->sst_dma +
263 					SSI_SST_BUFFER_CH_REG(msg->channel);
264 	}
265 	dev_dbg(&ssi->device, "lch %d cdsp %08x ccr %04x s_addr %08x d_addr %08x\n",
266 		lch, csdp, ccr, s_addr, d_addr);
267 
268 	writew_relaxed(csdp, gdd + SSI_GDD_CSDP_REG(lch));
269 	writew_relaxed(SSI_BLOCK_IE | SSI_TOUT_IE, gdd + SSI_GDD_CICR_REG(lch));
270 	writel_relaxed(d_addr, gdd + SSI_GDD_CDSA_REG(lch));
271 	writel_relaxed(s_addr, gdd + SSI_GDD_CSSA_REG(lch));
272 	writew_relaxed(SSI_BYTES_TO_FRAMES(msg->sgt.sgl->length),
273 						gdd + SSI_GDD_CEN_REG(lch));
274 
275 	spin_lock_bh(&omap_ssi->lock);
276 	tmp = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
277 	tmp |= SSI_GDD_LCH(lch);
278 	writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
279 	spin_unlock_bh(&omap_ssi->lock);
280 	writew(ccr, gdd + SSI_GDD_CCR_REG(lch));
281 	msg->status = HSI_STATUS_PROCEEDING;
282 
283 	return 0;
284 }
285 
286 static int ssi_start_pio(struct hsi_msg *msg)
287 {
288 	struct hsi_port *port = hsi_get_port(msg->cl);
289 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
290 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
291 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
292 	u32 val;
293 
294 	pm_runtime_get(omap_port->pdev);
295 
296 	if (!pm_runtime_active(omap_port->pdev)) {
297 		dev_warn(&port->device, "ssi_start_pio called without runtime PM!\n");
298 		pm_runtime_put_autosuspend(omap_port->pdev);
299 		return -EREMOTEIO;
300 	}
301 
302 	if (msg->ttype == HSI_MSG_WRITE) {
303 		val = SSI_DATAACCEPT(msg->channel);
304 		/* Hold clocks for pio writes */
305 		pm_runtime_get(omap_port->pdev);
306 	} else {
307 		val = SSI_DATAAVAILABLE(msg->channel) | SSI_ERROROCCURED;
308 	}
309 	dev_dbg(&port->device, "Single %s transfer\n",
310 						msg->ttype ? "write" : "read");
311 	val |= readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
312 	writel(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
313 	pm_runtime_put_autosuspend(omap_port->pdev);
314 	msg->actual_len = 0;
315 	msg->status = HSI_STATUS_PROCEEDING;
316 
317 	return 0;
318 }
319 
320 static int ssi_start_transfer(struct list_head *queue)
321 {
322 	struct hsi_msg *msg;
323 	int lch = -1;
324 
325 	if (list_empty(queue))
326 		return 0;
327 	msg = list_first_entry(queue, struct hsi_msg, link);
328 	if (msg->status != HSI_STATUS_QUEUED)
329 		return 0;
330 	if ((msg->sgt.nents) && (msg->sgt.sgl->length > sizeof(u32)))
331 		lch = ssi_claim_lch(msg);
332 	if (lch >= 0)
333 		return ssi_start_dma(msg, lch);
334 	else
335 		return ssi_start_pio(msg);
336 }
337 
338 static int ssi_async_break(struct hsi_msg *msg)
339 {
340 	struct hsi_port *port = hsi_get_port(msg->cl);
341 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
342 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
343 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
344 	int err = 0;
345 	u32 tmp;
346 
347 	pm_runtime_get_sync(omap_port->pdev);
348 	if (msg->ttype == HSI_MSG_WRITE) {
349 		if (omap_port->sst.mode != SSI_MODE_FRAME) {
350 			err = -EINVAL;
351 			goto out;
352 		}
353 		writel(1, omap_port->sst_base + SSI_SST_BREAK_REG);
354 		msg->status = HSI_STATUS_COMPLETED;
355 		msg->complete(msg);
356 	} else {
357 		if (omap_port->ssr.mode != SSI_MODE_FRAME) {
358 			err = -EINVAL;
359 			goto out;
360 		}
361 		spin_lock_bh(&omap_port->lock);
362 		tmp = readl(omap_ssi->sys +
363 					SSI_MPU_ENABLE_REG(port->num, 0));
364 		writel(tmp | SSI_BREAKDETECTED,
365 			omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
366 		msg->status = HSI_STATUS_PROCEEDING;
367 		list_add_tail(&msg->link, &omap_port->brkqueue);
368 		spin_unlock_bh(&omap_port->lock);
369 	}
370 out:
371 	pm_runtime_mark_last_busy(omap_port->pdev);
372 	pm_runtime_put_autosuspend(omap_port->pdev);
373 
374 	return err;
375 }
376 
377 static int ssi_async(struct hsi_msg *msg)
378 {
379 	struct hsi_port *port = hsi_get_port(msg->cl);
380 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
381 	struct list_head *queue;
382 	int err = 0;
383 
384 	BUG_ON(!msg);
385 
386 	if (msg->sgt.nents > 1)
387 		return -ENOSYS; /* TODO: Add sg support */
388 
389 	if (msg->break_frame)
390 		return ssi_async_break(msg);
391 
392 	if (msg->ttype) {
393 		BUG_ON(msg->channel >= omap_port->sst.channels);
394 		queue = &omap_port->txqueue[msg->channel];
395 	} else {
396 		BUG_ON(msg->channel >= omap_port->ssr.channels);
397 		queue = &omap_port->rxqueue[msg->channel];
398 	}
399 	msg->status = HSI_STATUS_QUEUED;
400 
401 	pm_runtime_get_sync(omap_port->pdev);
402 	spin_lock_bh(&omap_port->lock);
403 	list_add_tail(&msg->link, queue);
404 	err = ssi_start_transfer(queue);
405 	if (err < 0) {
406 		list_del(&msg->link);
407 		msg->status = HSI_STATUS_ERROR;
408 	}
409 	spin_unlock_bh(&omap_port->lock);
410 	pm_runtime_mark_last_busy(omap_port->pdev);
411 	pm_runtime_put_autosuspend(omap_port->pdev);
412 	dev_dbg(&port->device, "msg status %d ttype %d ch %d\n",
413 				msg->status, msg->ttype, msg->channel);
414 
415 	return err;
416 }
417 
418 static u32 ssi_calculate_div(struct hsi_controller *ssi)
419 {
420 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
421 	u32 tx_fckrate = (u32) omap_ssi->fck_rate;
422 
423 	/* / 2 : SSI TX clock is always half of the SSI functional clock */
424 	tx_fckrate >>= 1;
425 	/* Round down when tx_fckrate % omap_ssi->max_speed == 0 */
426 	tx_fckrate--;
427 	dev_dbg(&ssi->device, "TX div %d for fck_rate %lu Khz speed %d Kb/s\n",
428 		tx_fckrate / omap_ssi->max_speed, omap_ssi->fck_rate,
429 		omap_ssi->max_speed);
430 
431 	return tx_fckrate / omap_ssi->max_speed;
432 }
433 
434 static void ssi_flush_queue(struct list_head *queue, struct hsi_client *cl)
435 {
436 	struct list_head *node, *tmp;
437 	struct hsi_msg *msg;
438 
439 	list_for_each_safe(node, tmp, queue) {
440 		msg = list_entry(node, struct hsi_msg, link);
441 		if ((cl) && (cl != msg->cl))
442 			continue;
443 		list_del(node);
444 		pr_debug("flush queue: ch %d, msg %p len %d type %d ctxt %p\n",
445 			msg->channel, msg, msg->sgt.sgl->length,
446 					msg->ttype, msg->context);
447 		if (msg->destructor)
448 			msg->destructor(msg);
449 		else
450 			hsi_free_msg(msg);
451 	}
452 }
453 
454 static int ssi_setup(struct hsi_client *cl)
455 {
456 	struct hsi_port *port = to_hsi_port(cl->device.parent);
457 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
458 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
459 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
460 	void __iomem *sst = omap_port->sst_base;
461 	void __iomem *ssr = omap_port->ssr_base;
462 	u32 div;
463 	u32 val;
464 	int err = 0;
465 
466 	pm_runtime_get_sync(omap_port->pdev);
467 	spin_lock_bh(&omap_port->lock);
468 	if (cl->tx_cfg.speed)
469 		omap_ssi->max_speed = cl->tx_cfg.speed;
470 	div = ssi_calculate_div(ssi);
471 	if (div > SSI_MAX_DIVISOR) {
472 		dev_err(&cl->device, "Invalid TX speed %d Mb/s (div %d)\n",
473 						cl->tx_cfg.speed, div);
474 		err = -EINVAL;
475 		goto out;
476 	}
477 	/* Set TX/RX module to sleep to stop TX/RX during cfg update */
478 	writel_relaxed(SSI_MODE_SLEEP, sst + SSI_SST_MODE_REG);
479 	writel_relaxed(SSI_MODE_SLEEP, ssr + SSI_SSR_MODE_REG);
480 	/* Flush posted write */
481 	val = readl(ssr + SSI_SSR_MODE_REG);
482 	/* TX */
483 	writel_relaxed(31, sst + SSI_SST_FRAMESIZE_REG);
484 	writel_relaxed(div, sst + SSI_SST_DIVISOR_REG);
485 	writel_relaxed(cl->tx_cfg.num_hw_channels, sst + SSI_SST_CHANNELS_REG);
486 	writel_relaxed(cl->tx_cfg.arb_mode, sst + SSI_SST_ARBMODE_REG);
487 	writel_relaxed(cl->tx_cfg.mode, sst + SSI_SST_MODE_REG);
488 	/* RX */
489 	writel_relaxed(31, ssr + SSI_SSR_FRAMESIZE_REG);
490 	writel_relaxed(cl->rx_cfg.num_hw_channels, ssr + SSI_SSR_CHANNELS_REG);
491 	writel_relaxed(0, ssr + SSI_SSR_TIMEOUT_REG);
492 	/* Cleanup the break queue if we leave FRAME mode */
493 	if ((omap_port->ssr.mode == SSI_MODE_FRAME) &&
494 		(cl->rx_cfg.mode != SSI_MODE_FRAME))
495 		ssi_flush_queue(&omap_port->brkqueue, cl);
496 	writel_relaxed(cl->rx_cfg.mode, ssr + SSI_SSR_MODE_REG);
497 	omap_port->channels = max(cl->rx_cfg.num_hw_channels,
498 				  cl->tx_cfg.num_hw_channels);
499 	/* Shadow registering for OFF mode */
500 	/* SST */
501 	omap_port->sst.divisor = div;
502 	omap_port->sst.frame_size = 31;
503 	omap_port->sst.channels = cl->tx_cfg.num_hw_channels;
504 	omap_port->sst.arb_mode = cl->tx_cfg.arb_mode;
505 	omap_port->sst.mode = cl->tx_cfg.mode;
506 	/* SSR */
507 	omap_port->ssr.frame_size = 31;
508 	omap_port->ssr.timeout = 0;
509 	omap_port->ssr.channels = cl->rx_cfg.num_hw_channels;
510 	omap_port->ssr.mode = cl->rx_cfg.mode;
511 out:
512 	spin_unlock_bh(&omap_port->lock);
513 	pm_runtime_mark_last_busy(omap_port->pdev);
514 	pm_runtime_put_autosuspend(omap_port->pdev);
515 
516 	return err;
517 }
518 
519 static int ssi_flush(struct hsi_client *cl)
520 {
521 	struct hsi_port *port = hsi_get_port(cl);
522 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
523 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
524 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
525 	struct hsi_msg *msg;
526 	void __iomem *sst = omap_port->sst_base;
527 	void __iomem *ssr = omap_port->ssr_base;
528 	unsigned int i;
529 	u32 err;
530 
531 	pm_runtime_get_sync(omap_port->pdev);
532 	spin_lock_bh(&omap_port->lock);
533 
534 	/* stop all ssi communication */
535 	pinctrl_pm_select_idle_state(omap_port->pdev);
536 	udelay(1); /* wait for racing frames */
537 
538 	/* Stop all DMA transfers */
539 	for (i = 0; i < SSI_MAX_GDD_LCH; i++) {
540 		msg = omap_ssi->gdd_trn[i].msg;
541 		if (!msg || (port != hsi_get_port(msg->cl)))
542 			continue;
543 		writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
544 		if (msg->ttype == HSI_MSG_READ)
545 			pm_runtime_put_autosuspend(omap_port->pdev);
546 		omap_ssi->gdd_trn[i].msg = NULL;
547 	}
548 	/* Flush all SST buffers */
549 	writel_relaxed(0, sst + SSI_SST_BUFSTATE_REG);
550 	writel_relaxed(0, sst + SSI_SST_TXSTATE_REG);
551 	/* Flush all SSR buffers */
552 	writel_relaxed(0, ssr + SSI_SSR_RXSTATE_REG);
553 	writel_relaxed(0, ssr + SSI_SSR_BUFSTATE_REG);
554 	/* Flush all errors */
555 	err = readl(ssr + SSI_SSR_ERROR_REG);
556 	writel_relaxed(err, ssr + SSI_SSR_ERRORACK_REG);
557 	/* Flush break */
558 	writel_relaxed(0, ssr + SSI_SSR_BREAK_REG);
559 	/* Clear interrupts */
560 	writel_relaxed(0, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
561 	writel_relaxed(0xffffff00,
562 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
563 	writel_relaxed(0, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
564 	writel(0xff, omap_ssi->sys + SSI_GDD_MPU_IRQ_STATUS_REG);
565 	/* Dequeue all pending requests */
566 	for (i = 0; i < omap_port->channels; i++) {
567 		/* Release write clocks */
568 		if (!list_empty(&omap_port->txqueue[i]))
569 			pm_runtime_put_autosuspend(omap_port->pdev);
570 		ssi_flush_queue(&omap_port->txqueue[i], NULL);
571 		ssi_flush_queue(&omap_port->rxqueue[i], NULL);
572 	}
573 	ssi_flush_queue(&omap_port->brkqueue, NULL);
574 
575 	/* Resume SSI communication */
576 	pinctrl_pm_select_default_state(omap_port->pdev);
577 
578 	spin_unlock_bh(&omap_port->lock);
579 	pm_runtime_mark_last_busy(omap_port->pdev);
580 	pm_runtime_put_autosuspend(omap_port->pdev);
581 
582 	return 0;
583 }
584 
585 static void start_tx_work(struct work_struct *work)
586 {
587 	struct omap_ssi_port *omap_port =
588 				container_of(work, struct omap_ssi_port, work);
589 	struct hsi_port *port = to_hsi_port(omap_port->dev);
590 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
591 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
592 
593 	pm_runtime_get_sync(omap_port->pdev); /* Grab clocks */
594 	writel(SSI_WAKE(0), omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
595 }
596 
597 static int ssi_start_tx(struct hsi_client *cl)
598 {
599 	struct hsi_port *port = hsi_get_port(cl);
600 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
601 
602 	dev_dbg(&port->device, "Wake out high %d\n", omap_port->wk_refcount);
603 
604 	spin_lock_bh(&omap_port->wk_lock);
605 	if (omap_port->wk_refcount++) {
606 		spin_unlock_bh(&omap_port->wk_lock);
607 		return 0;
608 	}
609 	spin_unlock_bh(&omap_port->wk_lock);
610 
611 	schedule_work(&omap_port->work);
612 
613 	return 0;
614 }
615 
616 static int ssi_stop_tx(struct hsi_client *cl)
617 {
618 	struct hsi_port *port = hsi_get_port(cl);
619 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
620 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
621 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
622 
623 	dev_dbg(&port->device, "Wake out low %d\n", omap_port->wk_refcount);
624 
625 	spin_lock_bh(&omap_port->wk_lock);
626 	BUG_ON(!omap_port->wk_refcount);
627 	if (--omap_port->wk_refcount) {
628 		spin_unlock_bh(&omap_port->wk_lock);
629 		return 0;
630 	}
631 	writel(SSI_WAKE(0), omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
632 	spin_unlock_bh(&omap_port->wk_lock);
633 
634 	pm_runtime_mark_last_busy(omap_port->pdev);
635 	pm_runtime_put_autosuspend(omap_port->pdev); /* Release clocks */
636 
637 
638 	return 0;
639 }
640 
641 static void ssi_transfer(struct omap_ssi_port *omap_port,
642 							struct list_head *queue)
643 {
644 	struct hsi_msg *msg;
645 	int err = -1;
646 
647 	pm_runtime_get(omap_port->pdev);
648 	spin_lock_bh(&omap_port->lock);
649 	while (err < 0) {
650 		err = ssi_start_transfer(queue);
651 		if (err < 0) {
652 			msg = list_first_entry(queue, struct hsi_msg, link);
653 			msg->status = HSI_STATUS_ERROR;
654 			msg->actual_len = 0;
655 			list_del(&msg->link);
656 			spin_unlock_bh(&omap_port->lock);
657 			msg->complete(msg);
658 			spin_lock_bh(&omap_port->lock);
659 		}
660 	}
661 	spin_unlock_bh(&omap_port->lock);
662 	pm_runtime_mark_last_busy(omap_port->pdev);
663 	pm_runtime_put_autosuspend(omap_port->pdev);
664 }
665 
666 static void ssi_cleanup_queues(struct hsi_client *cl)
667 {
668 	struct hsi_port *port = hsi_get_port(cl);
669 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
670 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
671 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
672 	struct hsi_msg *msg;
673 	unsigned int i;
674 	u32 rxbufstate = 0;
675 	u32 txbufstate = 0;
676 	u32 status = SSI_ERROROCCURED;
677 	u32 tmp;
678 
679 	ssi_flush_queue(&omap_port->brkqueue, cl);
680 	if (list_empty(&omap_port->brkqueue))
681 		status |= SSI_BREAKDETECTED;
682 
683 	for (i = 0; i < omap_port->channels; i++) {
684 		if (list_empty(&omap_port->txqueue[i]))
685 			continue;
686 		msg = list_first_entry(&omap_port->txqueue[i], struct hsi_msg,
687 									link);
688 		if ((msg->cl == cl) && (msg->status == HSI_STATUS_PROCEEDING)) {
689 			txbufstate |= (1 << i);
690 			status |= SSI_DATAACCEPT(i);
691 			/* Release the clocks writes, also GDD ones */
692 			pm_runtime_mark_last_busy(omap_port->pdev);
693 			pm_runtime_put_autosuspend(omap_port->pdev);
694 		}
695 		ssi_flush_queue(&omap_port->txqueue[i], cl);
696 	}
697 	for (i = 0; i < omap_port->channels; i++) {
698 		if (list_empty(&omap_port->rxqueue[i]))
699 			continue;
700 		msg = list_first_entry(&omap_port->rxqueue[i], struct hsi_msg,
701 									link);
702 		if ((msg->cl == cl) && (msg->status == HSI_STATUS_PROCEEDING)) {
703 			rxbufstate |= (1 << i);
704 			status |= SSI_DATAAVAILABLE(i);
705 		}
706 		ssi_flush_queue(&omap_port->rxqueue[i], cl);
707 		/* Check if we keep the error detection interrupt armed */
708 		if (!list_empty(&omap_port->rxqueue[i]))
709 			status &= ~SSI_ERROROCCURED;
710 	}
711 	/* Cleanup write buffers */
712 	tmp = readl(omap_port->sst_base + SSI_SST_BUFSTATE_REG);
713 	tmp &= ~txbufstate;
714 	writel_relaxed(tmp, omap_port->sst_base + SSI_SST_BUFSTATE_REG);
715 	/* Cleanup read buffers */
716 	tmp = readl(omap_port->ssr_base + SSI_SSR_BUFSTATE_REG);
717 	tmp &= ~rxbufstate;
718 	writel_relaxed(tmp, omap_port->ssr_base + SSI_SSR_BUFSTATE_REG);
719 	/* Disarm and ack pending interrupts */
720 	tmp = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
721 	tmp &= ~status;
722 	writel_relaxed(tmp, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
723 	writel_relaxed(status, omap_ssi->sys +
724 		SSI_MPU_STATUS_REG(port->num, 0));
725 }
726 
727 static void ssi_cleanup_gdd(struct hsi_controller *ssi, struct hsi_client *cl)
728 {
729 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
730 	struct hsi_port *port = hsi_get_port(cl);
731 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
732 	struct hsi_msg *msg;
733 	unsigned int i;
734 	u32 val = 0;
735 	u32 tmp;
736 
737 	for (i = 0; i < SSI_MAX_GDD_LCH; i++) {
738 		msg = omap_ssi->gdd_trn[i].msg;
739 		if ((!msg) || (msg->cl != cl))
740 			continue;
741 		writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
742 		val |= (1 << i);
743 		/*
744 		 * Clock references for write will be handled in
745 		 * ssi_cleanup_queues
746 		 */
747 		if (msg->ttype == HSI_MSG_READ) {
748 			pm_runtime_mark_last_busy(omap_port->pdev);
749 			pm_runtime_put_autosuspend(omap_port->pdev);
750 		}
751 		omap_ssi->gdd_trn[i].msg = NULL;
752 	}
753 	tmp = readl_relaxed(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
754 	tmp &= ~val;
755 	writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
756 	writel(val, omap_ssi->sys + SSI_GDD_MPU_IRQ_STATUS_REG);
757 }
758 
759 static int ssi_set_port_mode(struct omap_ssi_port *omap_port, u32 mode)
760 {
761 	writel(mode, omap_port->sst_base + SSI_SST_MODE_REG);
762 	writel(mode, omap_port->ssr_base + SSI_SSR_MODE_REG);
763 	/* OCP barrier */
764 	mode = readl(omap_port->ssr_base + SSI_SSR_MODE_REG);
765 
766 	return 0;
767 }
768 
769 static int ssi_release(struct hsi_client *cl)
770 {
771 	struct hsi_port *port = hsi_get_port(cl);
772 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
773 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
774 
775 	pm_runtime_get_sync(omap_port->pdev);
776 	spin_lock_bh(&omap_port->lock);
777 	/* Stop all the pending DMA requests for that client */
778 	ssi_cleanup_gdd(ssi, cl);
779 	/* Now cleanup all the queues */
780 	ssi_cleanup_queues(cl);
781 	/* If it is the last client of the port, do extra checks and cleanup */
782 	if (port->claimed <= 1) {
783 		/*
784 		 * Drop the clock reference for the incoming wake line
785 		 * if it is still kept high by the other side.
786 		 */
787 		if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags))
788 			pm_runtime_put_sync(omap_port->pdev);
789 		pm_runtime_get(omap_port->pdev);
790 		/* Stop any SSI TX/RX without a client */
791 		ssi_set_port_mode(omap_port, SSI_MODE_SLEEP);
792 		omap_port->sst.mode = SSI_MODE_SLEEP;
793 		omap_port->ssr.mode = SSI_MODE_SLEEP;
794 		pm_runtime_put(omap_port->pdev);
795 		WARN_ON(omap_port->wk_refcount != 0);
796 	}
797 	spin_unlock_bh(&omap_port->lock);
798 	pm_runtime_put_sync(omap_port->pdev);
799 
800 	return 0;
801 }
802 
803 
804 
805 static void ssi_error(struct hsi_port *port)
806 {
807 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
808 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
809 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
810 	struct hsi_msg *msg;
811 	unsigned int i;
812 	u32 err;
813 	u32 val;
814 	u32 tmp;
815 
816 	/* ACK error */
817 	err = readl(omap_port->ssr_base + SSI_SSR_ERROR_REG);
818 	dev_err(&port->device, "SSI error: 0x%02x\n", err);
819 	if (!err) {
820 		dev_dbg(&port->device, "spurious SSI error ignored!\n");
821 		return;
822 	}
823 	spin_lock(&omap_ssi->lock);
824 	/* Cancel all GDD read transfers */
825 	for (i = 0, val = 0; i < SSI_MAX_GDD_LCH; i++) {
826 		msg = omap_ssi->gdd_trn[i].msg;
827 		if ((msg) && (msg->ttype == HSI_MSG_READ)) {
828 			writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
829 			val |= (1 << i);
830 			omap_ssi->gdd_trn[i].msg = NULL;
831 		}
832 	}
833 	tmp = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
834 	tmp &= ~val;
835 	writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
836 	spin_unlock(&omap_ssi->lock);
837 	/* Cancel all PIO read transfers */
838 	spin_lock(&omap_port->lock);
839 	tmp = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
840 	tmp &= 0xfeff00ff; /* Disable error & all dataavailable interrupts */
841 	writel_relaxed(tmp, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
842 	/* ACK error */
843 	writel_relaxed(err, omap_port->ssr_base + SSI_SSR_ERRORACK_REG);
844 	writel_relaxed(SSI_ERROROCCURED,
845 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
846 	/* Signal the error all current pending read requests */
847 	for (i = 0; i < omap_port->channels; i++) {
848 		if (list_empty(&omap_port->rxqueue[i]))
849 			continue;
850 		msg = list_first_entry(&omap_port->rxqueue[i], struct hsi_msg,
851 									link);
852 		list_del(&msg->link);
853 		msg->status = HSI_STATUS_ERROR;
854 		spin_unlock(&omap_port->lock);
855 		msg->complete(msg);
856 		/* Now restart queued reads if any */
857 		ssi_transfer(omap_port, &omap_port->rxqueue[i]);
858 		spin_lock(&omap_port->lock);
859 	}
860 	spin_unlock(&omap_port->lock);
861 }
862 
863 static void ssi_break_complete(struct hsi_port *port)
864 {
865 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
866 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
867 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
868 	struct hsi_msg *msg;
869 	struct hsi_msg *tmp;
870 	u32 val;
871 
872 	dev_dbg(&port->device, "HWBREAK received\n");
873 
874 	spin_lock(&omap_port->lock);
875 	val = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
876 	val &= ~SSI_BREAKDETECTED;
877 	writel_relaxed(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
878 	writel_relaxed(0, omap_port->ssr_base + SSI_SSR_BREAK_REG);
879 	writel(SSI_BREAKDETECTED,
880 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
881 	spin_unlock(&omap_port->lock);
882 
883 	list_for_each_entry_safe(msg, tmp, &omap_port->brkqueue, link) {
884 		msg->status = HSI_STATUS_COMPLETED;
885 		spin_lock(&omap_port->lock);
886 		list_del(&msg->link);
887 		spin_unlock(&omap_port->lock);
888 		msg->complete(msg);
889 	}
890 
891 }
892 
893 static void ssi_pio_complete(struct hsi_port *port, struct list_head *queue)
894 {
895 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
896 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
897 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
898 	struct hsi_msg *msg;
899 	u32 *buf;
900 	u32 reg;
901 	u32 val;
902 
903 	spin_lock_bh(&omap_port->lock);
904 	msg = list_first_entry(queue, struct hsi_msg, link);
905 	if ((!msg->sgt.nents) || (!msg->sgt.sgl->length)) {
906 		msg->actual_len = 0;
907 		msg->status = HSI_STATUS_PENDING;
908 	}
909 	if (msg->ttype == HSI_MSG_WRITE)
910 		val = SSI_DATAACCEPT(msg->channel);
911 	else
912 		val = SSI_DATAAVAILABLE(msg->channel);
913 	if (msg->status == HSI_STATUS_PROCEEDING) {
914 		buf = sg_virt(msg->sgt.sgl) + msg->actual_len;
915 		if (msg->ttype == HSI_MSG_WRITE)
916 			writel(*buf, omap_port->sst_base +
917 					SSI_SST_BUFFER_CH_REG(msg->channel));
918 		 else
919 			*buf = readl(omap_port->ssr_base +
920 					SSI_SSR_BUFFER_CH_REG(msg->channel));
921 		dev_dbg(&port->device, "ch %d ttype %d 0x%08x\n", msg->channel,
922 							msg->ttype, *buf);
923 		msg->actual_len += sizeof(*buf);
924 		if (msg->actual_len >= msg->sgt.sgl->length)
925 			msg->status = HSI_STATUS_COMPLETED;
926 		/*
927 		 * Wait for the last written frame to be really sent before
928 		 * we call the complete callback
929 		 */
930 		if ((msg->status == HSI_STATUS_PROCEEDING) ||
931 				((msg->status == HSI_STATUS_COMPLETED) &&
932 					(msg->ttype == HSI_MSG_WRITE))) {
933 			writel(val, omap_ssi->sys +
934 					SSI_MPU_STATUS_REG(port->num, 0));
935 			spin_unlock_bh(&omap_port->lock);
936 
937 			return;
938 		}
939 
940 	}
941 	/* Transfer completed at this point */
942 	reg = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
943 	if (msg->ttype == HSI_MSG_WRITE) {
944 		/* Release clocks for write transfer */
945 		pm_runtime_mark_last_busy(omap_port->pdev);
946 		pm_runtime_put_autosuspend(omap_port->pdev);
947 	}
948 	reg &= ~val;
949 	writel_relaxed(reg, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
950 	writel_relaxed(val, omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
951 	list_del(&msg->link);
952 	spin_unlock_bh(&omap_port->lock);
953 	msg->complete(msg);
954 	ssi_transfer(omap_port, queue);
955 }
956 
957 static irqreturn_t ssi_pio_thread(int irq, void *ssi_port)
958 {
959 	struct hsi_port *port = (struct hsi_port *)ssi_port;
960 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
961 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
962 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
963 	void __iomem *sys = omap_ssi->sys;
964 	unsigned int ch;
965 	u32 status_reg;
966 
967 	pm_runtime_get_sync(omap_port->pdev);
968 
969 	do {
970 		status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
971 		status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
972 
973 		for (ch = 0; ch < omap_port->channels; ch++) {
974 			if (status_reg & SSI_DATAACCEPT(ch))
975 				ssi_pio_complete(port, &omap_port->txqueue[ch]);
976 			if (status_reg & SSI_DATAAVAILABLE(ch))
977 				ssi_pio_complete(port, &omap_port->rxqueue[ch]);
978 		}
979 		if (status_reg & SSI_BREAKDETECTED)
980 			ssi_break_complete(port);
981 		if (status_reg & SSI_ERROROCCURED)
982 			ssi_error(port);
983 
984 		status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
985 		status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
986 
987 		/* TODO: sleep if we retry? */
988 	} while (status_reg);
989 
990 	pm_runtime_mark_last_busy(omap_port->pdev);
991 	pm_runtime_put_autosuspend(omap_port->pdev);
992 
993 	return IRQ_HANDLED;
994 }
995 
996 static irqreturn_t ssi_wake_thread(int irq __maybe_unused, void *ssi_port)
997 {
998 	struct hsi_port *port = (struct hsi_port *)ssi_port;
999 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1000 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1001 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1002 
1003 	if (ssi_wakein(port)) {
1004 		/**
1005 		 * We can have a quick High-Low-High transition in the line.
1006 		 * In such a case if we have long interrupt latencies,
1007 		 * we can miss the low event or get twice a high event.
1008 		 * This workaround will avoid breaking the clock reference
1009 		 * count when such a situation ocurrs.
1010 		 */
1011 		if (!test_and_set_bit(SSI_WAKE_EN, &omap_port->flags))
1012 			pm_runtime_get_sync(omap_port->pdev);
1013 		dev_dbg(&ssi->device, "Wake in high\n");
1014 		if (omap_port->wktest) { /* FIXME: HACK ! To be removed */
1015 			writel(SSI_WAKE(0),
1016 				omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
1017 		}
1018 		hsi_event(port, HSI_EVENT_START_RX);
1019 	} else {
1020 		dev_dbg(&ssi->device, "Wake in low\n");
1021 		if (omap_port->wktest) { /* FIXME: HACK ! To be removed */
1022 			writel(SSI_WAKE(0),
1023 				omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
1024 		}
1025 		hsi_event(port, HSI_EVENT_STOP_RX);
1026 		if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags)) {
1027 			pm_runtime_mark_last_busy(omap_port->pdev);
1028 			pm_runtime_put_autosuspend(omap_port->pdev);
1029 		}
1030 	}
1031 
1032 	return IRQ_HANDLED;
1033 }
1034 
1035 static int ssi_port_irq(struct hsi_port *port, struct platform_device *pd)
1036 {
1037 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1038 	int err;
1039 
1040 	err = platform_get_irq(pd, 0);
1041 	if (err < 0)
1042 		return err;
1043 	omap_port->irq = err;
1044 	err = devm_request_threaded_irq(&port->device, omap_port->irq, NULL,
1045 				ssi_pio_thread, IRQF_ONESHOT, "SSI PORT", port);
1046 	if (err < 0)
1047 		dev_err(&port->device, "Request IRQ %d failed (%d)\n",
1048 							omap_port->irq, err);
1049 	return err;
1050 }
1051 
1052 static int ssi_wake_irq(struct hsi_port *port, struct platform_device *pd)
1053 {
1054 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1055 	int cawake_irq;
1056 	int err;
1057 
1058 	if (!omap_port->wake_gpio) {
1059 		omap_port->wake_irq = -1;
1060 		return 0;
1061 	}
1062 
1063 	cawake_irq = gpiod_to_irq(omap_port->wake_gpio);
1064 	omap_port->wake_irq = cawake_irq;
1065 
1066 	err = devm_request_threaded_irq(&port->device, cawake_irq, NULL,
1067 		ssi_wake_thread,
1068 		IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1069 		"SSI cawake", port);
1070 	if (err < 0)
1071 		dev_err(&port->device, "Request Wake in IRQ %d failed %d\n",
1072 						cawake_irq, err);
1073 	err = enable_irq_wake(cawake_irq);
1074 	if (err < 0)
1075 		dev_err(&port->device, "Enable wake on the wakeline in irq %d failed %d\n",
1076 			cawake_irq, err);
1077 
1078 	return err;
1079 }
1080 
1081 static void ssi_queues_init(struct omap_ssi_port *omap_port)
1082 {
1083 	unsigned int ch;
1084 
1085 	for (ch = 0; ch < SSI_MAX_CHANNELS; ch++) {
1086 		INIT_LIST_HEAD(&omap_port->txqueue[ch]);
1087 		INIT_LIST_HEAD(&omap_port->rxqueue[ch]);
1088 	}
1089 	INIT_LIST_HEAD(&omap_port->brkqueue);
1090 }
1091 
1092 static int ssi_port_get_iomem(struct platform_device *pd,
1093 		const char *name, void __iomem **pbase, dma_addr_t *phy)
1094 {
1095 	struct hsi_port *port = platform_get_drvdata(pd);
1096 	struct resource *mem;
1097 	struct resource *ioarea;
1098 	void __iomem *base;
1099 
1100 	mem = platform_get_resource_byname(pd, IORESOURCE_MEM, name);
1101 	if (!mem) {
1102 		dev_err(&pd->dev, "IO memory region missing (%s)\n", name);
1103 		return -ENXIO;
1104 	}
1105 	ioarea = devm_request_mem_region(&port->device, mem->start,
1106 					resource_size(mem), dev_name(&pd->dev));
1107 	if (!ioarea) {
1108 		dev_err(&pd->dev, "%s IO memory region request failed\n",
1109 								mem->name);
1110 		return -ENXIO;
1111 	}
1112 	base = devm_ioremap(&port->device, mem->start, resource_size(mem));
1113 	if (!base) {
1114 		dev_err(&pd->dev, "%s IO remap failed\n", mem->name);
1115 		return -ENXIO;
1116 	}
1117 	*pbase = base;
1118 
1119 	if (phy)
1120 		*phy = mem->start;
1121 
1122 	return 0;
1123 }
1124 
1125 static int ssi_port_probe(struct platform_device *pd)
1126 {
1127 	struct device_node *np = pd->dev.of_node;
1128 	struct hsi_port *port;
1129 	struct omap_ssi_port *omap_port;
1130 	struct hsi_controller *ssi = dev_get_drvdata(pd->dev.parent);
1131 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1132 	struct gpio_desc *cawake_gpio = NULL;
1133 	u32 port_id;
1134 	int err;
1135 
1136 	dev_dbg(&pd->dev, "init ssi port...\n");
1137 
1138 	if (!ssi->port || !omap_ssi->port) {
1139 		dev_err(&pd->dev, "ssi controller not initialized!\n");
1140 		err = -ENODEV;
1141 		goto error;
1142 	}
1143 
1144 	/* get id of first uninitialized port in controller */
1145 	for (port_id = 0; port_id < ssi->num_ports && omap_ssi->port[port_id];
1146 		port_id++)
1147 		;
1148 
1149 	if (port_id >= ssi->num_ports) {
1150 		dev_err(&pd->dev, "port id out of range!\n");
1151 		err = -ENODEV;
1152 		goto error;
1153 	}
1154 
1155 	port = ssi->port[port_id];
1156 
1157 	if (!np) {
1158 		dev_err(&pd->dev, "missing device tree data\n");
1159 		err = -EINVAL;
1160 		goto error;
1161 	}
1162 
1163 	cawake_gpio = devm_gpiod_get(&pd->dev, "ti,ssi-cawake", GPIOD_IN);
1164 	if (IS_ERR(cawake_gpio)) {
1165 		err = PTR_ERR(cawake_gpio);
1166 		dev_err(&pd->dev, "couldn't get cawake gpio (err=%d)!\n", err);
1167 		goto error;
1168 	}
1169 
1170 	omap_port = devm_kzalloc(&port->device, sizeof(*omap_port), GFP_KERNEL);
1171 	if (!omap_port) {
1172 		err = -ENOMEM;
1173 		goto error;
1174 	}
1175 	omap_port->wake_gpio = cawake_gpio;
1176 	omap_port->pdev = &pd->dev;
1177 	omap_port->port_id = port_id;
1178 
1179 	INIT_DEFERRABLE_WORK(&omap_port->errqueue_work, ssi_process_errqueue);
1180 	INIT_WORK(&omap_port->work, start_tx_work);
1181 
1182 	/* initialize HSI port */
1183 	port->async	= ssi_async;
1184 	port->setup	= ssi_setup;
1185 	port->flush	= ssi_flush;
1186 	port->start_tx	= ssi_start_tx;
1187 	port->stop_tx	= ssi_stop_tx;
1188 	port->release	= ssi_release;
1189 	hsi_port_set_drvdata(port, omap_port);
1190 	omap_ssi->port[port_id] = omap_port;
1191 
1192 	platform_set_drvdata(pd, port);
1193 
1194 	err = ssi_port_get_iomem(pd, "tx", &omap_port->sst_base,
1195 		&omap_port->sst_dma);
1196 	if (err < 0)
1197 		goto error;
1198 	err = ssi_port_get_iomem(pd, "rx", &omap_port->ssr_base,
1199 		&omap_port->ssr_dma);
1200 	if (err < 0)
1201 		goto error;
1202 
1203 	err = ssi_port_irq(port, pd);
1204 	if (err < 0)
1205 		goto error;
1206 	err = ssi_wake_irq(port, pd);
1207 	if (err < 0)
1208 		goto error;
1209 
1210 	ssi_queues_init(omap_port);
1211 	spin_lock_init(&omap_port->lock);
1212 	spin_lock_init(&omap_port->wk_lock);
1213 	omap_port->dev = &port->device;
1214 
1215 	pm_runtime_use_autosuspend(omap_port->pdev);
1216 	pm_runtime_set_autosuspend_delay(omap_port->pdev, 250);
1217 	pm_runtime_enable(omap_port->pdev);
1218 
1219 #ifdef CONFIG_DEBUG_FS
1220 	err = ssi_debug_add_port(omap_port, omap_ssi->dir);
1221 	if (err < 0) {
1222 		pm_runtime_disable(omap_port->pdev);
1223 		goto error;
1224 	}
1225 #endif
1226 
1227 	hsi_add_clients_from_dt(port, np);
1228 
1229 	dev_info(&pd->dev, "ssi port %u successfully initialized\n", port_id);
1230 
1231 	return 0;
1232 
1233 error:
1234 	return err;
1235 }
1236 
1237 static int ssi_port_remove(struct platform_device *pd)
1238 {
1239 	struct hsi_port *port = platform_get_drvdata(pd);
1240 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1241 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1242 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1243 
1244 #ifdef CONFIG_DEBUG_FS
1245 	ssi_debug_remove_port(port);
1246 #endif
1247 
1248 	cancel_delayed_work_sync(&omap_port->errqueue_work);
1249 
1250 	hsi_port_unregister_clients(port);
1251 
1252 	port->async	= hsi_dummy_msg;
1253 	port->setup	= hsi_dummy_cl;
1254 	port->flush	= hsi_dummy_cl;
1255 	port->start_tx	= hsi_dummy_cl;
1256 	port->stop_tx	= hsi_dummy_cl;
1257 	port->release	= hsi_dummy_cl;
1258 
1259 	omap_ssi->port[omap_port->port_id] = NULL;
1260 	platform_set_drvdata(pd, NULL);
1261 
1262 	pm_runtime_dont_use_autosuspend(&pd->dev);
1263 	pm_runtime_disable(&pd->dev);
1264 
1265 	return 0;
1266 }
1267 
1268 static int ssi_restore_divisor(struct omap_ssi_port *omap_port)
1269 {
1270 	writel_relaxed(omap_port->sst.divisor,
1271 				omap_port->sst_base + SSI_SST_DIVISOR_REG);
1272 
1273 	return 0;
1274 }
1275 
1276 void omap_ssi_port_update_fclk(struct hsi_controller *ssi,
1277 			       struct omap_ssi_port *omap_port)
1278 {
1279 	/* update divisor */
1280 	u32 div = ssi_calculate_div(ssi);
1281 	omap_port->sst.divisor = div;
1282 	ssi_restore_divisor(omap_port);
1283 }
1284 
1285 #ifdef CONFIG_PM
1286 static int ssi_save_port_ctx(struct omap_ssi_port *omap_port)
1287 {
1288 	struct hsi_port *port = to_hsi_port(omap_port->dev);
1289 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1290 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1291 
1292 	omap_port->sys_mpu_enable = readl(omap_ssi->sys +
1293 					SSI_MPU_ENABLE_REG(port->num, 0));
1294 
1295 	return 0;
1296 }
1297 
1298 static int ssi_restore_port_ctx(struct omap_ssi_port *omap_port)
1299 {
1300 	struct hsi_port *port = to_hsi_port(omap_port->dev);
1301 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1302 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1303 	void __iomem	*base;
1304 
1305 	writel_relaxed(omap_port->sys_mpu_enable,
1306 			omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
1307 
1308 	/* SST context */
1309 	base = omap_port->sst_base;
1310 	writel_relaxed(omap_port->sst.frame_size, base + SSI_SST_FRAMESIZE_REG);
1311 	writel_relaxed(omap_port->sst.channels, base + SSI_SST_CHANNELS_REG);
1312 	writel_relaxed(omap_port->sst.arb_mode, base + SSI_SST_ARBMODE_REG);
1313 
1314 	/* SSR context */
1315 	base = omap_port->ssr_base;
1316 	writel_relaxed(omap_port->ssr.frame_size, base + SSI_SSR_FRAMESIZE_REG);
1317 	writel_relaxed(omap_port->ssr.channels, base + SSI_SSR_CHANNELS_REG);
1318 	writel_relaxed(omap_port->ssr.timeout, base + SSI_SSR_TIMEOUT_REG);
1319 
1320 	return 0;
1321 }
1322 
1323 static int ssi_restore_port_mode(struct omap_ssi_port *omap_port)
1324 {
1325 	u32 mode;
1326 
1327 	writel_relaxed(omap_port->sst.mode,
1328 				omap_port->sst_base + SSI_SST_MODE_REG);
1329 	writel_relaxed(omap_port->ssr.mode,
1330 				omap_port->ssr_base + SSI_SSR_MODE_REG);
1331 	/* OCP barrier */
1332 	mode = readl(omap_port->ssr_base + SSI_SSR_MODE_REG);
1333 
1334 	return 0;
1335 }
1336 
1337 static int omap_ssi_port_runtime_suspend(struct device *dev)
1338 {
1339 	struct hsi_port *port = dev_get_drvdata(dev);
1340 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1341 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1342 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1343 
1344 	dev_dbg(dev, "port runtime suspend!\n");
1345 
1346 	ssi_set_port_mode(omap_port, SSI_MODE_SLEEP);
1347 	if (omap_ssi->get_loss)
1348 		omap_port->loss_count =
1349 				omap_ssi->get_loss(ssi->device.parent);
1350 	ssi_save_port_ctx(omap_port);
1351 
1352 	return 0;
1353 }
1354 
1355 static int omap_ssi_port_runtime_resume(struct device *dev)
1356 {
1357 	struct hsi_port *port = dev_get_drvdata(dev);
1358 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1359 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1360 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1361 
1362 	dev_dbg(dev, "port runtime resume!\n");
1363 
1364 	if ((omap_ssi->get_loss) && (omap_port->loss_count ==
1365 				omap_ssi->get_loss(ssi->device.parent)))
1366 		goto mode; /* We always need to restore the mode & TX divisor */
1367 
1368 	ssi_restore_port_ctx(omap_port);
1369 
1370 mode:
1371 	ssi_restore_divisor(omap_port);
1372 	ssi_restore_port_mode(omap_port);
1373 
1374 	return 0;
1375 }
1376 
1377 static const struct dev_pm_ops omap_ssi_port_pm_ops = {
1378 	SET_RUNTIME_PM_OPS(omap_ssi_port_runtime_suspend,
1379 		omap_ssi_port_runtime_resume, NULL)
1380 };
1381 
1382 #define DEV_PM_OPS     (&omap_ssi_port_pm_ops)
1383 #else
1384 #define DEV_PM_OPS     NULL
1385 #endif
1386 
1387 
1388 #ifdef CONFIG_OF
1389 static const struct of_device_id omap_ssi_port_of_match[] = {
1390 	{ .compatible = "ti,omap3-ssi-port", },
1391 	{},
1392 };
1393 MODULE_DEVICE_TABLE(of, omap_ssi_port_of_match);
1394 #else
1395 #define omap_ssi_port_of_match NULL
1396 #endif
1397 
1398 struct platform_driver ssi_port_pdriver = {
1399 	.probe = ssi_port_probe,
1400 	.remove	= ssi_port_remove,
1401 	.driver	= {
1402 		.name	= "omap_ssi_port",
1403 		.of_match_table = omap_ssi_port_of_match,
1404 		.pm	= DEV_PM_OPS,
1405 	},
1406 };
1407