xref: /linux/drivers/hsi/controllers/omap_ssi_port.c (revision 55d0969c451159cff86949b38c39171cab962069)
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 void 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 	omap_port->dir = dir;
161 	debugfs_create_file("regs", S_IRUGO, dir, port, &ssi_port_regs_fops);
162 	dir = debugfs_create_dir("sst", dir);
163 	debugfs_create_file_unsafe("divisor", 0644, dir, port,
164 				   &ssi_sst_div_fops);
165 }
166 #endif
167 
168 static void ssi_process_errqueue(struct work_struct *work)
169 {
170 	struct omap_ssi_port *omap_port;
171 	struct list_head *head, *tmp;
172 	struct hsi_msg *msg;
173 
174 	omap_port = container_of(work, struct omap_ssi_port, errqueue_work.work);
175 
176 	list_for_each_safe(head, tmp, &omap_port->errqueue) {
177 		msg = list_entry(head, struct hsi_msg, link);
178 		msg->complete(msg);
179 		list_del(head);
180 	}
181 }
182 
183 static int ssi_claim_lch(struct hsi_msg *msg)
184 {
185 
186 	struct hsi_port *port = hsi_get_port(msg->cl);
187 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
188 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
189 	int lch;
190 
191 	for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++)
192 		if (!omap_ssi->gdd_trn[lch].msg) {
193 			omap_ssi->gdd_trn[lch].msg = msg;
194 			omap_ssi->gdd_trn[lch].sg = msg->sgt.sgl;
195 			return lch;
196 		}
197 
198 	return -EBUSY;
199 }
200 
201 static int ssi_start_dma(struct hsi_msg *msg, int lch)
202 {
203 	struct hsi_port *port = hsi_get_port(msg->cl);
204 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
205 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
206 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
207 	void __iomem *gdd = omap_ssi->gdd;
208 	int err;
209 	u16 csdp;
210 	u16 ccr;
211 	u32 s_addr;
212 	u32 d_addr;
213 	u32 tmp;
214 
215 	/* Hold clocks during the transfer */
216 	pm_runtime_get(omap_port->pdev);
217 
218 	if (!pm_runtime_active(omap_port->pdev)) {
219 		dev_warn(&port->device, "ssi_start_dma called without runtime PM!\n");
220 		pm_runtime_put_autosuspend(omap_port->pdev);
221 		return -EREMOTEIO;
222 	}
223 
224 	if (msg->ttype == HSI_MSG_READ) {
225 		err = dma_map_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents,
226 							DMA_FROM_DEVICE);
227 		if (!err) {
228 			dev_dbg(&ssi->device, "DMA map SG failed !\n");
229 			pm_runtime_put_autosuspend(omap_port->pdev);
230 			return -EIO;
231 		}
232 		csdp = SSI_DST_BURST_4x32_BIT | SSI_DST_MEMORY_PORT |
233 			SSI_SRC_SINGLE_ACCESS0 | SSI_SRC_PERIPHERAL_PORT |
234 			SSI_DATA_TYPE_S32;
235 		ccr = msg->channel + 0x10 + (port->num * 8); /* Sync */
236 		ccr |= SSI_DST_AMODE_POSTINC | SSI_SRC_AMODE_CONST |
237 			SSI_CCR_ENABLE;
238 		s_addr = omap_port->ssr_dma +
239 					SSI_SSR_BUFFER_CH_REG(msg->channel);
240 		d_addr = sg_dma_address(msg->sgt.sgl);
241 	} else {
242 		err = dma_map_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents,
243 							DMA_TO_DEVICE);
244 		if (!err) {
245 			dev_dbg(&ssi->device, "DMA map SG failed !\n");
246 			pm_runtime_put_autosuspend(omap_port->pdev);
247 			return -EIO;
248 		}
249 		csdp = SSI_SRC_BURST_4x32_BIT | SSI_SRC_MEMORY_PORT |
250 			SSI_DST_SINGLE_ACCESS0 | SSI_DST_PERIPHERAL_PORT |
251 			SSI_DATA_TYPE_S32;
252 		ccr = (msg->channel + 1 + (port->num * 8)) & 0xf; /* Sync */
253 		ccr |= SSI_SRC_AMODE_POSTINC | SSI_DST_AMODE_CONST |
254 			SSI_CCR_ENABLE;
255 		s_addr = sg_dma_address(msg->sgt.sgl);
256 		d_addr = omap_port->sst_dma +
257 					SSI_SST_BUFFER_CH_REG(msg->channel);
258 	}
259 	dev_dbg(&ssi->device, "lch %d cdsp %08x ccr %04x s_addr %08x d_addr %08x\n",
260 		lch, csdp, ccr, s_addr, d_addr);
261 
262 	writew_relaxed(csdp, gdd + SSI_GDD_CSDP_REG(lch));
263 	writew_relaxed(SSI_BLOCK_IE | SSI_TOUT_IE, gdd + SSI_GDD_CICR_REG(lch));
264 	writel_relaxed(d_addr, gdd + SSI_GDD_CDSA_REG(lch));
265 	writel_relaxed(s_addr, gdd + SSI_GDD_CSSA_REG(lch));
266 	writew_relaxed(SSI_BYTES_TO_FRAMES(msg->sgt.sgl->length),
267 						gdd + SSI_GDD_CEN_REG(lch));
268 
269 	spin_lock_bh(&omap_ssi->lock);
270 	tmp = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
271 	tmp |= SSI_GDD_LCH(lch);
272 	writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
273 	spin_unlock_bh(&omap_ssi->lock);
274 	writew(ccr, gdd + SSI_GDD_CCR_REG(lch));
275 	msg->status = HSI_STATUS_PROCEEDING;
276 
277 	return 0;
278 }
279 
280 static int ssi_start_pio(struct hsi_msg *msg)
281 {
282 	struct hsi_port *port = hsi_get_port(msg->cl);
283 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
284 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
285 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
286 	u32 val;
287 
288 	pm_runtime_get(omap_port->pdev);
289 
290 	if (!pm_runtime_active(omap_port->pdev)) {
291 		dev_warn(&port->device, "ssi_start_pio called without runtime PM!\n");
292 		pm_runtime_put_autosuspend(omap_port->pdev);
293 		return -EREMOTEIO;
294 	}
295 
296 	if (msg->ttype == HSI_MSG_WRITE) {
297 		val = SSI_DATAACCEPT(msg->channel);
298 		/* Hold clocks for pio writes */
299 		pm_runtime_get(omap_port->pdev);
300 	} else {
301 		val = SSI_DATAAVAILABLE(msg->channel) | SSI_ERROROCCURED;
302 	}
303 	dev_dbg(&port->device, "Single %s transfer\n",
304 						msg->ttype ? "write" : "read");
305 	val |= readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
306 	writel(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
307 	pm_runtime_put_autosuspend(omap_port->pdev);
308 	msg->actual_len = 0;
309 	msg->status = HSI_STATUS_PROCEEDING;
310 
311 	return 0;
312 }
313 
314 static int ssi_start_transfer(struct list_head *queue)
315 {
316 	struct hsi_msg *msg;
317 	int lch = -1;
318 
319 	if (list_empty(queue))
320 		return 0;
321 	msg = list_first_entry(queue, struct hsi_msg, link);
322 	if (msg->status != HSI_STATUS_QUEUED)
323 		return 0;
324 	if ((msg->sgt.nents) && (msg->sgt.sgl->length > sizeof(u32)))
325 		lch = ssi_claim_lch(msg);
326 	if (lch >= 0)
327 		return ssi_start_dma(msg, lch);
328 	else
329 		return ssi_start_pio(msg);
330 }
331 
332 static int ssi_async_break(struct hsi_msg *msg)
333 {
334 	struct hsi_port *port = hsi_get_port(msg->cl);
335 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
336 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
337 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
338 	int err = 0;
339 	u32 tmp;
340 
341 	pm_runtime_get_sync(omap_port->pdev);
342 	if (msg->ttype == HSI_MSG_WRITE) {
343 		if (omap_port->sst.mode != SSI_MODE_FRAME) {
344 			err = -EINVAL;
345 			goto out;
346 		}
347 		writel(1, omap_port->sst_base + SSI_SST_BREAK_REG);
348 		msg->status = HSI_STATUS_COMPLETED;
349 		msg->complete(msg);
350 	} else {
351 		if (omap_port->ssr.mode != SSI_MODE_FRAME) {
352 			err = -EINVAL;
353 			goto out;
354 		}
355 		spin_lock_bh(&omap_port->lock);
356 		tmp = readl(omap_ssi->sys +
357 					SSI_MPU_ENABLE_REG(port->num, 0));
358 		writel(tmp | SSI_BREAKDETECTED,
359 			omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
360 		msg->status = HSI_STATUS_PROCEEDING;
361 		list_add_tail(&msg->link, &omap_port->brkqueue);
362 		spin_unlock_bh(&omap_port->lock);
363 	}
364 out:
365 	pm_runtime_mark_last_busy(omap_port->pdev);
366 	pm_runtime_put_autosuspend(omap_port->pdev);
367 
368 	return err;
369 }
370 
371 static int ssi_async(struct hsi_msg *msg)
372 {
373 	struct hsi_port *port = hsi_get_port(msg->cl);
374 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
375 	struct list_head *queue;
376 	int err = 0;
377 
378 	BUG_ON(!msg);
379 
380 	if (msg->sgt.nents > 1)
381 		return -ENOSYS; /* TODO: Add sg support */
382 
383 	if (msg->break_frame)
384 		return ssi_async_break(msg);
385 
386 	if (msg->ttype) {
387 		BUG_ON(msg->channel >= omap_port->sst.channels);
388 		queue = &omap_port->txqueue[msg->channel];
389 	} else {
390 		BUG_ON(msg->channel >= omap_port->ssr.channels);
391 		queue = &omap_port->rxqueue[msg->channel];
392 	}
393 	msg->status = HSI_STATUS_QUEUED;
394 
395 	pm_runtime_get_sync(omap_port->pdev);
396 	spin_lock_bh(&omap_port->lock);
397 	list_add_tail(&msg->link, queue);
398 	err = ssi_start_transfer(queue);
399 	if (err < 0) {
400 		list_del(&msg->link);
401 		msg->status = HSI_STATUS_ERROR;
402 	}
403 	spin_unlock_bh(&omap_port->lock);
404 	pm_runtime_mark_last_busy(omap_port->pdev);
405 	pm_runtime_put_autosuspend(omap_port->pdev);
406 	dev_dbg(&port->device, "msg status %d ttype %d ch %d\n",
407 				msg->status, msg->ttype, msg->channel);
408 
409 	return err;
410 }
411 
412 static u32 ssi_calculate_div(struct hsi_controller *ssi)
413 {
414 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
415 	u32 tx_fckrate = (u32) omap_ssi->fck_rate;
416 
417 	/* / 2 : SSI TX clock is always half of the SSI functional clock */
418 	tx_fckrate >>= 1;
419 	/* Round down when tx_fckrate % omap_ssi->max_speed == 0 */
420 	tx_fckrate--;
421 	dev_dbg(&ssi->device, "TX div %d for fck_rate %lu Khz speed %d Kb/s\n",
422 		tx_fckrate / omap_ssi->max_speed, omap_ssi->fck_rate,
423 		omap_ssi->max_speed);
424 
425 	return tx_fckrate / omap_ssi->max_speed;
426 }
427 
428 static void ssi_flush_queue(struct list_head *queue, struct hsi_client *cl)
429 {
430 	struct list_head *node, *tmp;
431 	struct hsi_msg *msg;
432 
433 	list_for_each_safe(node, tmp, queue) {
434 		msg = list_entry(node, struct hsi_msg, link);
435 		if ((cl) && (cl != msg->cl))
436 			continue;
437 		list_del(node);
438 		pr_debug("flush queue: ch %d, msg %p len %d type %d ctxt %p\n",
439 			msg->channel, msg, msg->sgt.sgl->length,
440 					msg->ttype, msg->context);
441 		if (msg->destructor)
442 			msg->destructor(msg);
443 		else
444 			hsi_free_msg(msg);
445 	}
446 }
447 
448 static int ssi_setup(struct hsi_client *cl)
449 {
450 	struct hsi_port *port = to_hsi_port(cl->device.parent);
451 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
452 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
453 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
454 	void __iomem *sst = omap_port->sst_base;
455 	void __iomem *ssr = omap_port->ssr_base;
456 	u32 div;
457 	u32 val;
458 	int err = 0;
459 
460 	pm_runtime_get_sync(omap_port->pdev);
461 	spin_lock_bh(&omap_port->lock);
462 	if (cl->tx_cfg.speed)
463 		omap_ssi->max_speed = cl->tx_cfg.speed;
464 	div = ssi_calculate_div(ssi);
465 	if (div > SSI_MAX_DIVISOR) {
466 		dev_err(&cl->device, "Invalid TX speed %d Mb/s (div %d)\n",
467 						cl->tx_cfg.speed, div);
468 		err = -EINVAL;
469 		goto out;
470 	}
471 	/* Set TX/RX module to sleep to stop TX/RX during cfg update */
472 	writel_relaxed(SSI_MODE_SLEEP, sst + SSI_SST_MODE_REG);
473 	writel_relaxed(SSI_MODE_SLEEP, ssr + SSI_SSR_MODE_REG);
474 	/* Flush posted write */
475 	val = readl(ssr + SSI_SSR_MODE_REG);
476 	/* TX */
477 	writel_relaxed(31, sst + SSI_SST_FRAMESIZE_REG);
478 	writel_relaxed(div, sst + SSI_SST_DIVISOR_REG);
479 	writel_relaxed(cl->tx_cfg.num_hw_channels, sst + SSI_SST_CHANNELS_REG);
480 	writel_relaxed(cl->tx_cfg.arb_mode, sst + SSI_SST_ARBMODE_REG);
481 	writel_relaxed(cl->tx_cfg.mode, sst + SSI_SST_MODE_REG);
482 	/* RX */
483 	writel_relaxed(31, ssr + SSI_SSR_FRAMESIZE_REG);
484 	writel_relaxed(cl->rx_cfg.num_hw_channels, ssr + SSI_SSR_CHANNELS_REG);
485 	writel_relaxed(0, ssr + SSI_SSR_TIMEOUT_REG);
486 	/* Cleanup the break queue if we leave FRAME mode */
487 	if ((omap_port->ssr.mode == SSI_MODE_FRAME) &&
488 		(cl->rx_cfg.mode != SSI_MODE_FRAME))
489 		ssi_flush_queue(&omap_port->brkqueue, cl);
490 	writel_relaxed(cl->rx_cfg.mode, ssr + SSI_SSR_MODE_REG);
491 	omap_port->channels = max(cl->rx_cfg.num_hw_channels,
492 				  cl->tx_cfg.num_hw_channels);
493 	/* Shadow registering for OFF mode */
494 	/* SST */
495 	omap_port->sst.divisor = div;
496 	omap_port->sst.frame_size = 31;
497 	omap_port->sst.channels = cl->tx_cfg.num_hw_channels;
498 	omap_port->sst.arb_mode = cl->tx_cfg.arb_mode;
499 	omap_port->sst.mode = cl->tx_cfg.mode;
500 	/* SSR */
501 	omap_port->ssr.frame_size = 31;
502 	omap_port->ssr.timeout = 0;
503 	omap_port->ssr.channels = cl->rx_cfg.num_hw_channels;
504 	omap_port->ssr.mode = cl->rx_cfg.mode;
505 out:
506 	spin_unlock_bh(&omap_port->lock);
507 	pm_runtime_mark_last_busy(omap_port->pdev);
508 	pm_runtime_put_autosuspend(omap_port->pdev);
509 
510 	return err;
511 }
512 
513 static int ssi_flush(struct hsi_client *cl)
514 {
515 	struct hsi_port *port = hsi_get_port(cl);
516 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
517 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
518 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
519 	struct hsi_msg *msg;
520 	void __iomem *sst = omap_port->sst_base;
521 	void __iomem *ssr = omap_port->ssr_base;
522 	unsigned int i;
523 	u32 err;
524 
525 	pm_runtime_get_sync(omap_port->pdev);
526 	spin_lock_bh(&omap_port->lock);
527 
528 	/* stop all ssi communication */
529 	pinctrl_pm_select_idle_state(omap_port->pdev);
530 	udelay(1); /* wait for racing frames */
531 
532 	/* Stop all DMA transfers */
533 	for (i = 0; i < SSI_MAX_GDD_LCH; i++) {
534 		msg = omap_ssi->gdd_trn[i].msg;
535 		if (!msg || (port != hsi_get_port(msg->cl)))
536 			continue;
537 		writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
538 		if (msg->ttype == HSI_MSG_READ)
539 			pm_runtime_put_autosuspend(omap_port->pdev);
540 		omap_ssi->gdd_trn[i].msg = NULL;
541 	}
542 	/* Flush all SST buffers */
543 	writel_relaxed(0, sst + SSI_SST_BUFSTATE_REG);
544 	writel_relaxed(0, sst + SSI_SST_TXSTATE_REG);
545 	/* Flush all SSR buffers */
546 	writel_relaxed(0, ssr + SSI_SSR_RXSTATE_REG);
547 	writel_relaxed(0, ssr + SSI_SSR_BUFSTATE_REG);
548 	/* Flush all errors */
549 	err = readl(ssr + SSI_SSR_ERROR_REG);
550 	writel_relaxed(err, ssr + SSI_SSR_ERRORACK_REG);
551 	/* Flush break */
552 	writel_relaxed(0, ssr + SSI_SSR_BREAK_REG);
553 	/* Clear interrupts */
554 	writel_relaxed(0, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
555 	writel_relaxed(0xffffff00,
556 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
557 	writel_relaxed(0, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
558 	writel(0xff, omap_ssi->sys + SSI_GDD_MPU_IRQ_STATUS_REG);
559 	/* Dequeue all pending requests */
560 	for (i = 0; i < omap_port->channels; i++) {
561 		/* Release write clocks */
562 		if (!list_empty(&omap_port->txqueue[i]))
563 			pm_runtime_put_autosuspend(omap_port->pdev);
564 		ssi_flush_queue(&omap_port->txqueue[i], NULL);
565 		ssi_flush_queue(&omap_port->rxqueue[i], NULL);
566 	}
567 	ssi_flush_queue(&omap_port->brkqueue, NULL);
568 
569 	/* Resume SSI communication */
570 	pinctrl_pm_select_default_state(omap_port->pdev);
571 
572 	spin_unlock_bh(&omap_port->lock);
573 	pm_runtime_mark_last_busy(omap_port->pdev);
574 	pm_runtime_put_autosuspend(omap_port->pdev);
575 
576 	return 0;
577 }
578 
579 static void start_tx_work(struct work_struct *work)
580 {
581 	struct omap_ssi_port *omap_port =
582 				container_of(work, struct omap_ssi_port, work);
583 	struct hsi_port *port = to_hsi_port(omap_port->dev);
584 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
585 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
586 
587 	pm_runtime_get_sync(omap_port->pdev); /* Grab clocks */
588 	writel(SSI_WAKE(0), omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
589 }
590 
591 static int ssi_start_tx(struct hsi_client *cl)
592 {
593 	struct hsi_port *port = hsi_get_port(cl);
594 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
595 
596 	dev_dbg(&port->device, "Wake out high %d\n", omap_port->wk_refcount);
597 
598 	spin_lock_bh(&omap_port->wk_lock);
599 	if (omap_port->wk_refcount++) {
600 		spin_unlock_bh(&omap_port->wk_lock);
601 		return 0;
602 	}
603 	spin_unlock_bh(&omap_port->wk_lock);
604 
605 	schedule_work(&omap_port->work);
606 
607 	return 0;
608 }
609 
610 static int ssi_stop_tx(struct hsi_client *cl)
611 {
612 	struct hsi_port *port = hsi_get_port(cl);
613 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
614 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
615 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
616 
617 	dev_dbg(&port->device, "Wake out low %d\n", omap_port->wk_refcount);
618 
619 	spin_lock_bh(&omap_port->wk_lock);
620 	BUG_ON(!omap_port->wk_refcount);
621 	if (--omap_port->wk_refcount) {
622 		spin_unlock_bh(&omap_port->wk_lock);
623 		return 0;
624 	}
625 	writel(SSI_WAKE(0), omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
626 	spin_unlock_bh(&omap_port->wk_lock);
627 
628 	pm_runtime_mark_last_busy(omap_port->pdev);
629 	pm_runtime_put_autosuspend(omap_port->pdev); /* Release clocks */
630 
631 
632 	return 0;
633 }
634 
635 static void ssi_transfer(struct omap_ssi_port *omap_port,
636 							struct list_head *queue)
637 {
638 	struct hsi_msg *msg;
639 	int err = -1;
640 
641 	pm_runtime_get(omap_port->pdev);
642 	spin_lock_bh(&omap_port->lock);
643 	while (err < 0) {
644 		err = ssi_start_transfer(queue);
645 		if (err < 0) {
646 			msg = list_first_entry(queue, struct hsi_msg, link);
647 			msg->status = HSI_STATUS_ERROR;
648 			msg->actual_len = 0;
649 			list_del(&msg->link);
650 			spin_unlock_bh(&omap_port->lock);
651 			msg->complete(msg);
652 			spin_lock_bh(&omap_port->lock);
653 		}
654 	}
655 	spin_unlock_bh(&omap_port->lock);
656 	pm_runtime_mark_last_busy(omap_port->pdev);
657 	pm_runtime_put_autosuspend(omap_port->pdev);
658 }
659 
660 static void ssi_cleanup_queues(struct hsi_client *cl)
661 {
662 	struct hsi_port *port = hsi_get_port(cl);
663 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
664 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
665 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
666 	struct hsi_msg *msg;
667 	unsigned int i;
668 	u32 rxbufstate = 0;
669 	u32 txbufstate = 0;
670 	u32 status = SSI_ERROROCCURED;
671 	u32 tmp;
672 
673 	ssi_flush_queue(&omap_port->brkqueue, cl);
674 	if (list_empty(&omap_port->brkqueue))
675 		status |= SSI_BREAKDETECTED;
676 
677 	for (i = 0; i < omap_port->channels; i++) {
678 		if (list_empty(&omap_port->txqueue[i]))
679 			continue;
680 		msg = list_first_entry(&omap_port->txqueue[i], struct hsi_msg,
681 									link);
682 		if ((msg->cl == cl) && (msg->status == HSI_STATUS_PROCEEDING)) {
683 			txbufstate |= (1 << i);
684 			status |= SSI_DATAACCEPT(i);
685 			/* Release the clocks writes, also GDD ones */
686 			pm_runtime_mark_last_busy(omap_port->pdev);
687 			pm_runtime_put_autosuspend(omap_port->pdev);
688 		}
689 		ssi_flush_queue(&omap_port->txqueue[i], cl);
690 	}
691 	for (i = 0; i < omap_port->channels; i++) {
692 		if (list_empty(&omap_port->rxqueue[i]))
693 			continue;
694 		msg = list_first_entry(&omap_port->rxqueue[i], struct hsi_msg,
695 									link);
696 		if ((msg->cl == cl) && (msg->status == HSI_STATUS_PROCEEDING)) {
697 			rxbufstate |= (1 << i);
698 			status |= SSI_DATAAVAILABLE(i);
699 		}
700 		ssi_flush_queue(&omap_port->rxqueue[i], cl);
701 		/* Check if we keep the error detection interrupt armed */
702 		if (!list_empty(&omap_port->rxqueue[i]))
703 			status &= ~SSI_ERROROCCURED;
704 	}
705 	/* Cleanup write buffers */
706 	tmp = readl(omap_port->sst_base + SSI_SST_BUFSTATE_REG);
707 	tmp &= ~txbufstate;
708 	writel_relaxed(tmp, omap_port->sst_base + SSI_SST_BUFSTATE_REG);
709 	/* Cleanup read buffers */
710 	tmp = readl(omap_port->ssr_base + SSI_SSR_BUFSTATE_REG);
711 	tmp &= ~rxbufstate;
712 	writel_relaxed(tmp, omap_port->ssr_base + SSI_SSR_BUFSTATE_REG);
713 	/* Disarm and ack pending interrupts */
714 	tmp = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
715 	tmp &= ~status;
716 	writel_relaxed(tmp, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
717 	writel_relaxed(status, omap_ssi->sys +
718 		SSI_MPU_STATUS_REG(port->num, 0));
719 }
720 
721 static void ssi_cleanup_gdd(struct hsi_controller *ssi, struct hsi_client *cl)
722 {
723 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
724 	struct hsi_port *port = hsi_get_port(cl);
725 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
726 	struct hsi_msg *msg;
727 	unsigned int i;
728 	u32 val = 0;
729 	u32 tmp;
730 
731 	for (i = 0; i < SSI_MAX_GDD_LCH; i++) {
732 		msg = omap_ssi->gdd_trn[i].msg;
733 		if ((!msg) || (msg->cl != cl))
734 			continue;
735 		writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
736 		val |= (1 << i);
737 		/*
738 		 * Clock references for write will be handled in
739 		 * ssi_cleanup_queues
740 		 */
741 		if (msg->ttype == HSI_MSG_READ) {
742 			pm_runtime_mark_last_busy(omap_port->pdev);
743 			pm_runtime_put_autosuspend(omap_port->pdev);
744 		}
745 		omap_ssi->gdd_trn[i].msg = NULL;
746 	}
747 	tmp = readl_relaxed(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
748 	tmp &= ~val;
749 	writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
750 	writel(val, omap_ssi->sys + SSI_GDD_MPU_IRQ_STATUS_REG);
751 }
752 
753 static int ssi_set_port_mode(struct omap_ssi_port *omap_port, u32 mode)
754 {
755 	writel(mode, omap_port->sst_base + SSI_SST_MODE_REG);
756 	writel(mode, omap_port->ssr_base + SSI_SSR_MODE_REG);
757 	/* OCP barrier */
758 	mode = readl(omap_port->ssr_base + SSI_SSR_MODE_REG);
759 
760 	return 0;
761 }
762 
763 static int ssi_release(struct hsi_client *cl)
764 {
765 	struct hsi_port *port = hsi_get_port(cl);
766 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
767 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
768 
769 	pm_runtime_get_sync(omap_port->pdev);
770 	spin_lock_bh(&omap_port->lock);
771 	/* Stop all the pending DMA requests for that client */
772 	ssi_cleanup_gdd(ssi, cl);
773 	/* Now cleanup all the queues */
774 	ssi_cleanup_queues(cl);
775 	/* If it is the last client of the port, do extra checks and cleanup */
776 	if (port->claimed <= 1) {
777 		/*
778 		 * Drop the clock reference for the incoming wake line
779 		 * if it is still kept high by the other side.
780 		 */
781 		if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags))
782 			pm_runtime_put_sync(omap_port->pdev);
783 		pm_runtime_get(omap_port->pdev);
784 		/* Stop any SSI TX/RX without a client */
785 		ssi_set_port_mode(omap_port, SSI_MODE_SLEEP);
786 		omap_port->sst.mode = SSI_MODE_SLEEP;
787 		omap_port->ssr.mode = SSI_MODE_SLEEP;
788 		pm_runtime_put(omap_port->pdev);
789 		WARN_ON(omap_port->wk_refcount != 0);
790 	}
791 	spin_unlock_bh(&omap_port->lock);
792 	pm_runtime_put_sync(omap_port->pdev);
793 
794 	return 0;
795 }
796 
797 
798 
799 static void ssi_error(struct hsi_port *port)
800 {
801 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
802 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
803 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
804 	struct hsi_msg *msg;
805 	unsigned int i;
806 	u32 err;
807 	u32 val;
808 	u32 tmp;
809 
810 	/* ACK error */
811 	err = readl(omap_port->ssr_base + SSI_SSR_ERROR_REG);
812 	dev_err(&port->device, "SSI error: 0x%02x\n", err);
813 	if (!err) {
814 		dev_dbg(&port->device, "spurious SSI error ignored!\n");
815 		return;
816 	}
817 	spin_lock(&omap_ssi->lock);
818 	/* Cancel all GDD read transfers */
819 	for (i = 0, val = 0; i < SSI_MAX_GDD_LCH; i++) {
820 		msg = omap_ssi->gdd_trn[i].msg;
821 		if ((msg) && (msg->ttype == HSI_MSG_READ)) {
822 			writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
823 			val |= (1 << i);
824 			omap_ssi->gdd_trn[i].msg = NULL;
825 		}
826 	}
827 	tmp = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
828 	tmp &= ~val;
829 	writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
830 	spin_unlock(&omap_ssi->lock);
831 	/* Cancel all PIO read transfers */
832 	spin_lock(&omap_port->lock);
833 	tmp = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
834 	tmp &= 0xfeff00ff; /* Disable error & all dataavailable interrupts */
835 	writel_relaxed(tmp, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
836 	/* ACK error */
837 	writel_relaxed(err, omap_port->ssr_base + SSI_SSR_ERRORACK_REG);
838 	writel_relaxed(SSI_ERROROCCURED,
839 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
840 	/* Signal the error all current pending read requests */
841 	for (i = 0; i < omap_port->channels; i++) {
842 		if (list_empty(&omap_port->rxqueue[i]))
843 			continue;
844 		msg = list_first_entry(&omap_port->rxqueue[i], struct hsi_msg,
845 									link);
846 		list_del(&msg->link);
847 		msg->status = HSI_STATUS_ERROR;
848 		spin_unlock(&omap_port->lock);
849 		msg->complete(msg);
850 		/* Now restart queued reads if any */
851 		ssi_transfer(omap_port, &omap_port->rxqueue[i]);
852 		spin_lock(&omap_port->lock);
853 	}
854 	spin_unlock(&omap_port->lock);
855 }
856 
857 static void ssi_break_complete(struct hsi_port *port)
858 {
859 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
860 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
861 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
862 	struct hsi_msg *msg;
863 	struct hsi_msg *tmp;
864 	u32 val;
865 
866 	dev_dbg(&port->device, "HWBREAK received\n");
867 
868 	spin_lock(&omap_port->lock);
869 	val = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
870 	val &= ~SSI_BREAKDETECTED;
871 	writel_relaxed(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
872 	writel_relaxed(0, omap_port->ssr_base + SSI_SSR_BREAK_REG);
873 	writel(SSI_BREAKDETECTED,
874 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
875 	spin_unlock(&omap_port->lock);
876 
877 	list_for_each_entry_safe(msg, tmp, &omap_port->brkqueue, link) {
878 		msg->status = HSI_STATUS_COMPLETED;
879 		spin_lock(&omap_port->lock);
880 		list_del(&msg->link);
881 		spin_unlock(&omap_port->lock);
882 		msg->complete(msg);
883 	}
884 
885 }
886 
887 static void ssi_pio_complete(struct hsi_port *port, struct list_head *queue)
888 {
889 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
890 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
891 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
892 	struct hsi_msg *msg;
893 	u32 *buf;
894 	u32 reg;
895 	u32 val;
896 
897 	spin_lock_bh(&omap_port->lock);
898 	msg = list_first_entry(queue, struct hsi_msg, link);
899 	if ((!msg->sgt.nents) || (!msg->sgt.sgl->length)) {
900 		msg->actual_len = 0;
901 		msg->status = HSI_STATUS_PENDING;
902 	}
903 	if (msg->ttype == HSI_MSG_WRITE)
904 		val = SSI_DATAACCEPT(msg->channel);
905 	else
906 		val = SSI_DATAAVAILABLE(msg->channel);
907 	if (msg->status == HSI_STATUS_PROCEEDING) {
908 		buf = sg_virt(msg->sgt.sgl) + msg->actual_len;
909 		if (msg->ttype == HSI_MSG_WRITE)
910 			writel(*buf, omap_port->sst_base +
911 					SSI_SST_BUFFER_CH_REG(msg->channel));
912 		 else
913 			*buf = readl(omap_port->ssr_base +
914 					SSI_SSR_BUFFER_CH_REG(msg->channel));
915 		dev_dbg(&port->device, "ch %d ttype %d 0x%08x\n", msg->channel,
916 							msg->ttype, *buf);
917 		msg->actual_len += sizeof(*buf);
918 		if (msg->actual_len >= msg->sgt.sgl->length)
919 			msg->status = HSI_STATUS_COMPLETED;
920 		/*
921 		 * Wait for the last written frame to be really sent before
922 		 * we call the complete callback
923 		 */
924 		if ((msg->status == HSI_STATUS_PROCEEDING) ||
925 				((msg->status == HSI_STATUS_COMPLETED) &&
926 					(msg->ttype == HSI_MSG_WRITE))) {
927 			writel(val, omap_ssi->sys +
928 					SSI_MPU_STATUS_REG(port->num, 0));
929 			spin_unlock_bh(&omap_port->lock);
930 
931 			return;
932 		}
933 
934 	}
935 	/* Transfer completed at this point */
936 	reg = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
937 	if (msg->ttype == HSI_MSG_WRITE) {
938 		/* Release clocks for write transfer */
939 		pm_runtime_mark_last_busy(omap_port->pdev);
940 		pm_runtime_put_autosuspend(omap_port->pdev);
941 	}
942 	reg &= ~val;
943 	writel_relaxed(reg, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
944 	writel_relaxed(val, omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
945 	list_del(&msg->link);
946 	spin_unlock_bh(&omap_port->lock);
947 	msg->complete(msg);
948 	ssi_transfer(omap_port, queue);
949 }
950 
951 static irqreturn_t ssi_pio_thread(int irq, void *ssi_port)
952 {
953 	struct hsi_port *port = (struct hsi_port *)ssi_port;
954 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
955 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
956 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
957 	void __iomem *sys = omap_ssi->sys;
958 	unsigned int ch;
959 	u32 status_reg;
960 
961 	pm_runtime_get_sync(omap_port->pdev);
962 
963 	do {
964 		status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
965 		status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
966 
967 		for (ch = 0; ch < omap_port->channels; ch++) {
968 			if (status_reg & SSI_DATAACCEPT(ch))
969 				ssi_pio_complete(port, &omap_port->txqueue[ch]);
970 			if (status_reg & SSI_DATAAVAILABLE(ch))
971 				ssi_pio_complete(port, &omap_port->rxqueue[ch]);
972 		}
973 		if (status_reg & SSI_BREAKDETECTED)
974 			ssi_break_complete(port);
975 		if (status_reg & SSI_ERROROCCURED)
976 			ssi_error(port);
977 
978 		status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
979 		status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
980 
981 		/* TODO: sleep if we retry? */
982 	} while (status_reg);
983 
984 	pm_runtime_mark_last_busy(omap_port->pdev);
985 	pm_runtime_put_autosuspend(omap_port->pdev);
986 
987 	return IRQ_HANDLED;
988 }
989 
990 static irqreturn_t ssi_wake_thread(int irq __maybe_unused, void *ssi_port)
991 {
992 	struct hsi_port *port = (struct hsi_port *)ssi_port;
993 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
994 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
995 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
996 
997 	if (ssi_wakein(port)) {
998 		/**
999 		 * We can have a quick High-Low-High transition in the line.
1000 		 * In such a case if we have long interrupt latencies,
1001 		 * we can miss the low event or get twice a high event.
1002 		 * This workaround will avoid breaking the clock reference
1003 		 * count when such a situation ocurrs.
1004 		 */
1005 		if (!test_and_set_bit(SSI_WAKE_EN, &omap_port->flags))
1006 			pm_runtime_get_sync(omap_port->pdev);
1007 		dev_dbg(&ssi->device, "Wake in high\n");
1008 		if (omap_port->wktest) { /* FIXME: HACK ! To be removed */
1009 			writel(SSI_WAKE(0),
1010 				omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
1011 		}
1012 		hsi_event(port, HSI_EVENT_START_RX);
1013 	} else {
1014 		dev_dbg(&ssi->device, "Wake in low\n");
1015 		if (omap_port->wktest) { /* FIXME: HACK ! To be removed */
1016 			writel(SSI_WAKE(0),
1017 				omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
1018 		}
1019 		hsi_event(port, HSI_EVENT_STOP_RX);
1020 		if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags)) {
1021 			pm_runtime_mark_last_busy(omap_port->pdev);
1022 			pm_runtime_put_autosuspend(omap_port->pdev);
1023 		}
1024 	}
1025 
1026 	return IRQ_HANDLED;
1027 }
1028 
1029 static int ssi_port_irq(struct hsi_port *port, struct platform_device *pd)
1030 {
1031 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1032 	int err;
1033 
1034 	err = platform_get_irq(pd, 0);
1035 	if (err < 0)
1036 		return err;
1037 	omap_port->irq = err;
1038 	err = devm_request_threaded_irq(&port->device, omap_port->irq, NULL,
1039 				ssi_pio_thread, IRQF_ONESHOT, "SSI PORT", port);
1040 	if (err < 0)
1041 		dev_err(&port->device, "Request IRQ %d failed (%d)\n",
1042 							omap_port->irq, err);
1043 	return err;
1044 }
1045 
1046 static int ssi_wake_irq(struct hsi_port *port, struct platform_device *pd)
1047 {
1048 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1049 	int cawake_irq;
1050 	int err;
1051 
1052 	if (!omap_port->wake_gpio) {
1053 		omap_port->wake_irq = -1;
1054 		return 0;
1055 	}
1056 
1057 	cawake_irq = gpiod_to_irq(omap_port->wake_gpio);
1058 	omap_port->wake_irq = cawake_irq;
1059 
1060 	err = devm_request_threaded_irq(&port->device, cawake_irq, NULL,
1061 		ssi_wake_thread,
1062 		IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1063 		"SSI cawake", port);
1064 	if (err < 0)
1065 		dev_err(&port->device, "Request Wake in IRQ %d failed %d\n",
1066 						cawake_irq, err);
1067 	err = enable_irq_wake(cawake_irq);
1068 	if (err < 0)
1069 		dev_err(&port->device, "Enable wake on the wakeline in irq %d failed %d\n",
1070 			cawake_irq, err);
1071 
1072 	return err;
1073 }
1074 
1075 static void ssi_queues_init(struct omap_ssi_port *omap_port)
1076 {
1077 	unsigned int ch;
1078 
1079 	for (ch = 0; ch < SSI_MAX_CHANNELS; ch++) {
1080 		INIT_LIST_HEAD(&omap_port->txqueue[ch]);
1081 		INIT_LIST_HEAD(&omap_port->rxqueue[ch]);
1082 	}
1083 	INIT_LIST_HEAD(&omap_port->brkqueue);
1084 }
1085 
1086 static int ssi_port_get_iomem(struct platform_device *pd,
1087 		const char *name, void __iomem **pbase, dma_addr_t *phy)
1088 {
1089 	struct hsi_port *port = platform_get_drvdata(pd);
1090 	struct resource *mem;
1091 	struct resource *ioarea;
1092 	void __iomem *base;
1093 
1094 	mem = platform_get_resource_byname(pd, IORESOURCE_MEM, name);
1095 	if (!mem) {
1096 		dev_err(&pd->dev, "IO memory region missing (%s)\n", name);
1097 		return -ENXIO;
1098 	}
1099 	ioarea = devm_request_mem_region(&port->device, mem->start,
1100 					resource_size(mem), dev_name(&pd->dev));
1101 	if (!ioarea) {
1102 		dev_err(&pd->dev, "%s IO memory region request failed\n",
1103 								mem->name);
1104 		return -ENXIO;
1105 	}
1106 	base = devm_ioremap(&port->device, mem->start, resource_size(mem));
1107 	if (!base) {
1108 		dev_err(&pd->dev, "%s IO remap failed\n", mem->name);
1109 		return -ENXIO;
1110 	}
1111 	*pbase = base;
1112 
1113 	if (phy)
1114 		*phy = mem->start;
1115 
1116 	return 0;
1117 }
1118 
1119 static int ssi_port_probe(struct platform_device *pd)
1120 {
1121 	struct device_node *np = pd->dev.of_node;
1122 	struct hsi_port *port;
1123 	struct omap_ssi_port *omap_port;
1124 	struct hsi_controller *ssi = dev_get_drvdata(pd->dev.parent);
1125 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1126 	struct gpio_desc *cawake_gpio = NULL;
1127 	u32 port_id;
1128 	int err;
1129 
1130 	dev_dbg(&pd->dev, "init ssi port...\n");
1131 
1132 	if (!ssi->port || !omap_ssi->port) {
1133 		dev_err(&pd->dev, "ssi controller not initialized!\n");
1134 		err = -ENODEV;
1135 		goto error;
1136 	}
1137 
1138 	/* get id of first uninitialized port in controller */
1139 	for (port_id = 0; port_id < ssi->num_ports && omap_ssi->port[port_id];
1140 		port_id++)
1141 		;
1142 
1143 	if (port_id >= ssi->num_ports) {
1144 		dev_err(&pd->dev, "port id out of range!\n");
1145 		err = -ENODEV;
1146 		goto error;
1147 	}
1148 
1149 	port = ssi->port[port_id];
1150 
1151 	if (!np) {
1152 		dev_err(&pd->dev, "missing device tree data\n");
1153 		err = -EINVAL;
1154 		goto error;
1155 	}
1156 
1157 	cawake_gpio = devm_gpiod_get(&pd->dev, "ti,ssi-cawake", GPIOD_IN);
1158 	if (IS_ERR(cawake_gpio)) {
1159 		err = PTR_ERR(cawake_gpio);
1160 		dev_err(&pd->dev, "couldn't get cawake gpio (err=%d)!\n", err);
1161 		goto error;
1162 	}
1163 
1164 	omap_port = devm_kzalloc(&port->device, sizeof(*omap_port), GFP_KERNEL);
1165 	if (!omap_port) {
1166 		err = -ENOMEM;
1167 		goto error;
1168 	}
1169 	omap_port->wake_gpio = cawake_gpio;
1170 	omap_port->pdev = &pd->dev;
1171 	omap_port->port_id = port_id;
1172 
1173 	INIT_DEFERRABLE_WORK(&omap_port->errqueue_work, ssi_process_errqueue);
1174 	INIT_WORK(&omap_port->work, start_tx_work);
1175 
1176 	/* initialize HSI port */
1177 	port->async	= ssi_async;
1178 	port->setup	= ssi_setup;
1179 	port->flush	= ssi_flush;
1180 	port->start_tx	= ssi_start_tx;
1181 	port->stop_tx	= ssi_stop_tx;
1182 	port->release	= ssi_release;
1183 	hsi_port_set_drvdata(port, omap_port);
1184 	omap_ssi->port[port_id] = omap_port;
1185 
1186 	platform_set_drvdata(pd, port);
1187 
1188 	err = ssi_port_get_iomem(pd, "tx", &omap_port->sst_base,
1189 		&omap_port->sst_dma);
1190 	if (err < 0)
1191 		goto error;
1192 	err = ssi_port_get_iomem(pd, "rx", &omap_port->ssr_base,
1193 		&omap_port->ssr_dma);
1194 	if (err < 0)
1195 		goto error;
1196 
1197 	err = ssi_port_irq(port, pd);
1198 	if (err < 0)
1199 		goto error;
1200 	err = ssi_wake_irq(port, pd);
1201 	if (err < 0)
1202 		goto error;
1203 
1204 	ssi_queues_init(omap_port);
1205 	spin_lock_init(&omap_port->lock);
1206 	spin_lock_init(&omap_port->wk_lock);
1207 	omap_port->dev = &port->device;
1208 
1209 	pm_runtime_use_autosuspend(omap_port->pdev);
1210 	pm_runtime_set_autosuspend_delay(omap_port->pdev, 250);
1211 	pm_runtime_enable(omap_port->pdev);
1212 
1213 #ifdef CONFIG_DEBUG_FS
1214 	ssi_debug_add_port(omap_port, omap_ssi->dir);
1215 #endif
1216 
1217 	hsi_add_clients_from_dt(port, np);
1218 
1219 	dev_info(&pd->dev, "ssi port %u successfully initialized\n", port_id);
1220 
1221 	return 0;
1222 
1223 error:
1224 	return err;
1225 }
1226 
1227 static void ssi_port_remove(struct platform_device *pd)
1228 {
1229 	struct hsi_port *port = platform_get_drvdata(pd);
1230 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1231 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1232 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1233 
1234 #ifdef CONFIG_DEBUG_FS
1235 	ssi_debug_remove_port(port);
1236 #endif
1237 
1238 	cancel_delayed_work_sync(&omap_port->errqueue_work);
1239 
1240 	hsi_port_unregister_clients(port);
1241 
1242 	port->async	= hsi_dummy_msg;
1243 	port->setup	= hsi_dummy_cl;
1244 	port->flush	= hsi_dummy_cl;
1245 	port->start_tx	= hsi_dummy_cl;
1246 	port->stop_tx	= hsi_dummy_cl;
1247 	port->release	= hsi_dummy_cl;
1248 
1249 	omap_ssi->port[omap_port->port_id] = NULL;
1250 	platform_set_drvdata(pd, NULL);
1251 
1252 	pm_runtime_dont_use_autosuspend(&pd->dev);
1253 	pm_runtime_disable(&pd->dev);
1254 }
1255 
1256 static int ssi_restore_divisor(struct omap_ssi_port *omap_port)
1257 {
1258 	writel_relaxed(omap_port->sst.divisor,
1259 				omap_port->sst_base + SSI_SST_DIVISOR_REG);
1260 
1261 	return 0;
1262 }
1263 
1264 void omap_ssi_port_update_fclk(struct hsi_controller *ssi,
1265 			       struct omap_ssi_port *omap_port)
1266 {
1267 	/* update divisor */
1268 	u32 div = ssi_calculate_div(ssi);
1269 	omap_port->sst.divisor = div;
1270 	ssi_restore_divisor(omap_port);
1271 }
1272 
1273 #ifdef CONFIG_PM
1274 static int ssi_save_port_ctx(struct omap_ssi_port *omap_port)
1275 {
1276 	struct hsi_port *port = to_hsi_port(omap_port->dev);
1277 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1278 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1279 
1280 	omap_port->sys_mpu_enable = readl(omap_ssi->sys +
1281 					SSI_MPU_ENABLE_REG(port->num, 0));
1282 
1283 	return 0;
1284 }
1285 
1286 static int ssi_restore_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 	void __iomem	*base;
1292 
1293 	writel_relaxed(omap_port->sys_mpu_enable,
1294 			omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
1295 
1296 	/* SST context */
1297 	base = omap_port->sst_base;
1298 	writel_relaxed(omap_port->sst.frame_size, base + SSI_SST_FRAMESIZE_REG);
1299 	writel_relaxed(omap_port->sst.channels, base + SSI_SST_CHANNELS_REG);
1300 	writel_relaxed(omap_port->sst.arb_mode, base + SSI_SST_ARBMODE_REG);
1301 
1302 	/* SSR context */
1303 	base = omap_port->ssr_base;
1304 	writel_relaxed(omap_port->ssr.frame_size, base + SSI_SSR_FRAMESIZE_REG);
1305 	writel_relaxed(omap_port->ssr.channels, base + SSI_SSR_CHANNELS_REG);
1306 	writel_relaxed(omap_port->ssr.timeout, base + SSI_SSR_TIMEOUT_REG);
1307 
1308 	return 0;
1309 }
1310 
1311 static int ssi_restore_port_mode(struct omap_ssi_port *omap_port)
1312 {
1313 	u32 mode;
1314 
1315 	writel_relaxed(omap_port->sst.mode,
1316 				omap_port->sst_base + SSI_SST_MODE_REG);
1317 	writel_relaxed(omap_port->ssr.mode,
1318 				omap_port->ssr_base + SSI_SSR_MODE_REG);
1319 	/* OCP barrier */
1320 	mode = readl(omap_port->ssr_base + SSI_SSR_MODE_REG);
1321 
1322 	return 0;
1323 }
1324 
1325 static int omap_ssi_port_runtime_suspend(struct device *dev)
1326 {
1327 	struct hsi_port *port = dev_get_drvdata(dev);
1328 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1329 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1330 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1331 
1332 	dev_dbg(dev, "port runtime suspend!\n");
1333 
1334 	ssi_set_port_mode(omap_port, SSI_MODE_SLEEP);
1335 	if (omap_ssi->get_loss)
1336 		omap_port->loss_count =
1337 				omap_ssi->get_loss(ssi->device.parent);
1338 	ssi_save_port_ctx(omap_port);
1339 
1340 	return 0;
1341 }
1342 
1343 static int omap_ssi_port_runtime_resume(struct device *dev)
1344 {
1345 	struct hsi_port *port = dev_get_drvdata(dev);
1346 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1347 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1348 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1349 
1350 	dev_dbg(dev, "port runtime resume!\n");
1351 
1352 	if ((omap_ssi->get_loss) && (omap_port->loss_count ==
1353 				omap_ssi->get_loss(ssi->device.parent)))
1354 		goto mode; /* We always need to restore the mode & TX divisor */
1355 
1356 	ssi_restore_port_ctx(omap_port);
1357 
1358 mode:
1359 	ssi_restore_divisor(omap_port);
1360 	ssi_restore_port_mode(omap_port);
1361 
1362 	return 0;
1363 }
1364 
1365 static const struct dev_pm_ops omap_ssi_port_pm_ops = {
1366 	SET_RUNTIME_PM_OPS(omap_ssi_port_runtime_suspend,
1367 		omap_ssi_port_runtime_resume, NULL)
1368 };
1369 
1370 #define DEV_PM_OPS     (&omap_ssi_port_pm_ops)
1371 #else
1372 #define DEV_PM_OPS     NULL
1373 #endif
1374 
1375 
1376 #ifdef CONFIG_OF
1377 static const struct of_device_id omap_ssi_port_of_match[] = {
1378 	{ .compatible = "ti,omap3-ssi-port", },
1379 	{},
1380 };
1381 MODULE_DEVICE_TABLE(of, omap_ssi_port_of_match);
1382 #else
1383 #define omap_ssi_port_of_match NULL
1384 #endif
1385 
1386 struct platform_driver ssi_port_pdriver = {
1387 	.probe = ssi_port_probe,
1388 	.remove_new = ssi_port_remove,
1389 	.driver	= {
1390 		.name	= "omap_ssi_port",
1391 		.of_match_table = omap_ssi_port_of_match,
1392 		.pm	= DEV_PM_OPS,
1393 	},
1394 };
1395