xref: /linux/drivers/hsi/controllers/omap_ssi_port.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
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_put_autosuspend(omap_port->pdev);
366 
367 	return err;
368 }
369 
370 static int ssi_async(struct hsi_msg *msg)
371 {
372 	struct hsi_port *port = hsi_get_port(msg->cl);
373 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
374 	struct list_head *queue;
375 	int err = 0;
376 
377 	BUG_ON(!msg);
378 
379 	if (msg->sgt.nents > 1)
380 		return -ENOSYS; /* TODO: Add sg support */
381 
382 	if (msg->break_frame)
383 		return ssi_async_break(msg);
384 
385 	if (msg->ttype) {
386 		BUG_ON(msg->channel >= omap_port->sst.channels);
387 		queue = &omap_port->txqueue[msg->channel];
388 	} else {
389 		BUG_ON(msg->channel >= omap_port->ssr.channels);
390 		queue = &omap_port->rxqueue[msg->channel];
391 	}
392 	msg->status = HSI_STATUS_QUEUED;
393 
394 	pm_runtime_get_sync(omap_port->pdev);
395 	spin_lock_bh(&omap_port->lock);
396 	list_add_tail(&msg->link, queue);
397 	err = ssi_start_transfer(queue);
398 	if (err < 0) {
399 		list_del(&msg->link);
400 		msg->status = HSI_STATUS_ERROR;
401 	}
402 	spin_unlock_bh(&omap_port->lock);
403 	pm_runtime_put_autosuspend(omap_port->pdev);
404 	dev_dbg(&port->device, "msg status %d ttype %d ch %d\n",
405 				msg->status, msg->ttype, msg->channel);
406 
407 	return err;
408 }
409 
410 static u32 ssi_calculate_div(struct hsi_controller *ssi)
411 {
412 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
413 	u32 tx_fckrate = (u32) omap_ssi->fck_rate;
414 
415 	/* / 2 : SSI TX clock is always half of the SSI functional clock */
416 	tx_fckrate >>= 1;
417 	/* Round down when tx_fckrate % omap_ssi->max_speed == 0 */
418 	tx_fckrate--;
419 	dev_dbg(&ssi->device, "TX div %d for fck_rate %lu Khz speed %d Kb/s\n",
420 		tx_fckrate / omap_ssi->max_speed, omap_ssi->fck_rate,
421 		omap_ssi->max_speed);
422 
423 	return tx_fckrate / omap_ssi->max_speed;
424 }
425 
426 static void ssi_flush_queue(struct list_head *queue, struct hsi_client *cl)
427 {
428 	struct list_head *node, *tmp;
429 	struct hsi_msg *msg;
430 
431 	list_for_each_safe(node, tmp, queue) {
432 		msg = list_entry(node, struct hsi_msg, link);
433 		if ((cl) && (cl != msg->cl))
434 			continue;
435 		list_del(node);
436 		pr_debug("flush queue: ch %d, msg %p len %d type %d ctxt %p\n",
437 			msg->channel, msg, msg->sgt.sgl->length,
438 					msg->ttype, msg->context);
439 		if (msg->destructor)
440 			msg->destructor(msg);
441 		else
442 			hsi_free_msg(msg);
443 	}
444 }
445 
446 static int ssi_setup(struct hsi_client *cl)
447 {
448 	struct hsi_port *port = to_hsi_port(cl->device.parent);
449 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
450 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
451 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
452 	void __iomem *sst = omap_port->sst_base;
453 	void __iomem *ssr = omap_port->ssr_base;
454 	u32 div;
455 	u32 val;
456 	int err = 0;
457 
458 	pm_runtime_get_sync(omap_port->pdev);
459 	spin_lock_bh(&omap_port->lock);
460 	if (cl->tx_cfg.speed)
461 		omap_ssi->max_speed = cl->tx_cfg.speed;
462 	div = ssi_calculate_div(ssi);
463 	if (div > SSI_MAX_DIVISOR) {
464 		dev_err(&cl->device, "Invalid TX speed %d Mb/s (div %d)\n",
465 						cl->tx_cfg.speed, div);
466 		err = -EINVAL;
467 		goto out;
468 	}
469 	/* Set TX/RX module to sleep to stop TX/RX during cfg update */
470 	writel_relaxed(SSI_MODE_SLEEP, sst + SSI_SST_MODE_REG);
471 	writel_relaxed(SSI_MODE_SLEEP, ssr + SSI_SSR_MODE_REG);
472 	/* Flush posted write */
473 	val = readl(ssr + SSI_SSR_MODE_REG);
474 	/* TX */
475 	writel_relaxed(31, sst + SSI_SST_FRAMESIZE_REG);
476 	writel_relaxed(div, sst + SSI_SST_DIVISOR_REG);
477 	writel_relaxed(cl->tx_cfg.num_hw_channels, sst + SSI_SST_CHANNELS_REG);
478 	writel_relaxed(cl->tx_cfg.arb_mode, sst + SSI_SST_ARBMODE_REG);
479 	writel_relaxed(cl->tx_cfg.mode, sst + SSI_SST_MODE_REG);
480 	/* RX */
481 	writel_relaxed(31, ssr + SSI_SSR_FRAMESIZE_REG);
482 	writel_relaxed(cl->rx_cfg.num_hw_channels, ssr + SSI_SSR_CHANNELS_REG);
483 	writel_relaxed(0, ssr + SSI_SSR_TIMEOUT_REG);
484 	/* Cleanup the break queue if we leave FRAME mode */
485 	if ((omap_port->ssr.mode == SSI_MODE_FRAME) &&
486 		(cl->rx_cfg.mode != SSI_MODE_FRAME))
487 		ssi_flush_queue(&omap_port->brkqueue, cl);
488 	writel_relaxed(cl->rx_cfg.mode, ssr + SSI_SSR_MODE_REG);
489 	omap_port->channels = max(cl->rx_cfg.num_hw_channels,
490 				  cl->tx_cfg.num_hw_channels);
491 	/* Shadow registering for OFF mode */
492 	/* SST */
493 	omap_port->sst.divisor = div;
494 	omap_port->sst.frame_size = 31;
495 	omap_port->sst.channels = cl->tx_cfg.num_hw_channels;
496 	omap_port->sst.arb_mode = cl->tx_cfg.arb_mode;
497 	omap_port->sst.mode = cl->tx_cfg.mode;
498 	/* SSR */
499 	omap_port->ssr.frame_size = 31;
500 	omap_port->ssr.timeout = 0;
501 	omap_port->ssr.channels = cl->rx_cfg.num_hw_channels;
502 	omap_port->ssr.mode = cl->rx_cfg.mode;
503 out:
504 	spin_unlock_bh(&omap_port->lock);
505 	pm_runtime_put_autosuspend(omap_port->pdev);
506 
507 	return err;
508 }
509 
510 static int ssi_flush(struct hsi_client *cl)
511 {
512 	struct hsi_port *port = hsi_get_port(cl);
513 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
514 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
515 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
516 	struct hsi_msg *msg;
517 	void __iomem *sst = omap_port->sst_base;
518 	void __iomem *ssr = omap_port->ssr_base;
519 	unsigned int i;
520 	u32 err;
521 
522 	pm_runtime_get_sync(omap_port->pdev);
523 	spin_lock_bh(&omap_port->lock);
524 
525 	/* stop all ssi communication */
526 	pinctrl_pm_select_idle_state(omap_port->pdev);
527 	udelay(1); /* wait for racing frames */
528 
529 	/* Stop all DMA transfers */
530 	for (i = 0; i < SSI_MAX_GDD_LCH; i++) {
531 		msg = omap_ssi->gdd_trn[i].msg;
532 		if (!msg || (port != hsi_get_port(msg->cl)))
533 			continue;
534 		writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
535 		if (msg->ttype == HSI_MSG_READ)
536 			pm_runtime_put_autosuspend(omap_port->pdev);
537 		omap_ssi->gdd_trn[i].msg = NULL;
538 	}
539 	/* Flush all SST buffers */
540 	writel_relaxed(0, sst + SSI_SST_BUFSTATE_REG);
541 	writel_relaxed(0, sst + SSI_SST_TXSTATE_REG);
542 	/* Flush all SSR buffers */
543 	writel_relaxed(0, ssr + SSI_SSR_RXSTATE_REG);
544 	writel_relaxed(0, ssr + SSI_SSR_BUFSTATE_REG);
545 	/* Flush all errors */
546 	err = readl(ssr + SSI_SSR_ERROR_REG);
547 	writel_relaxed(err, ssr + SSI_SSR_ERRORACK_REG);
548 	/* Flush break */
549 	writel_relaxed(0, ssr + SSI_SSR_BREAK_REG);
550 	/* Clear interrupts */
551 	writel_relaxed(0, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
552 	writel_relaxed(0xffffff00,
553 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
554 	writel_relaxed(0, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
555 	writel(0xff, omap_ssi->sys + SSI_GDD_MPU_IRQ_STATUS_REG);
556 	/* Dequeue all pending requests */
557 	for (i = 0; i < omap_port->channels; i++) {
558 		/* Release write clocks */
559 		if (!list_empty(&omap_port->txqueue[i]))
560 			pm_runtime_put_autosuspend(omap_port->pdev);
561 		ssi_flush_queue(&omap_port->txqueue[i], NULL);
562 		ssi_flush_queue(&omap_port->rxqueue[i], NULL);
563 	}
564 	ssi_flush_queue(&omap_port->brkqueue, NULL);
565 
566 	/* Resume SSI communication */
567 	pinctrl_pm_select_default_state(omap_port->pdev);
568 
569 	spin_unlock_bh(&omap_port->lock);
570 	pm_runtime_put_autosuspend(omap_port->pdev);
571 
572 	return 0;
573 }
574 
575 static void start_tx_work(struct work_struct *work)
576 {
577 	struct omap_ssi_port *omap_port =
578 				container_of(work, struct omap_ssi_port, work);
579 	struct hsi_port *port = to_hsi_port(omap_port->dev);
580 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
581 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
582 
583 	pm_runtime_get_sync(omap_port->pdev); /* Grab clocks */
584 	writel(SSI_WAKE(0), omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
585 }
586 
587 static int ssi_start_tx(struct hsi_client *cl)
588 {
589 	struct hsi_port *port = hsi_get_port(cl);
590 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
591 
592 	dev_dbg(&port->device, "Wake out high %d\n", omap_port->wk_refcount);
593 
594 	spin_lock_bh(&omap_port->wk_lock);
595 	if (omap_port->wk_refcount++) {
596 		spin_unlock_bh(&omap_port->wk_lock);
597 		return 0;
598 	}
599 	spin_unlock_bh(&omap_port->wk_lock);
600 
601 	schedule_work(&omap_port->work);
602 
603 	return 0;
604 }
605 
606 static int ssi_stop_tx(struct hsi_client *cl)
607 {
608 	struct hsi_port *port = hsi_get_port(cl);
609 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
610 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
611 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
612 
613 	dev_dbg(&port->device, "Wake out low %d\n", omap_port->wk_refcount);
614 
615 	spin_lock_bh(&omap_port->wk_lock);
616 	BUG_ON(!omap_port->wk_refcount);
617 	if (--omap_port->wk_refcount) {
618 		spin_unlock_bh(&omap_port->wk_lock);
619 		return 0;
620 	}
621 	writel(SSI_WAKE(0), omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
622 	spin_unlock_bh(&omap_port->wk_lock);
623 
624 	pm_runtime_put_autosuspend(omap_port->pdev); /* Release clocks */
625 
626 
627 	return 0;
628 }
629 
630 static void ssi_transfer(struct omap_ssi_port *omap_port,
631 							struct list_head *queue)
632 {
633 	struct hsi_msg *msg;
634 	int err = -1;
635 
636 	pm_runtime_get(omap_port->pdev);
637 	spin_lock_bh(&omap_port->lock);
638 	while (err < 0) {
639 		err = ssi_start_transfer(queue);
640 		if (err < 0) {
641 			msg = list_first_entry(queue, struct hsi_msg, link);
642 			msg->status = HSI_STATUS_ERROR;
643 			msg->actual_len = 0;
644 			list_del(&msg->link);
645 			spin_unlock_bh(&omap_port->lock);
646 			msg->complete(msg);
647 			spin_lock_bh(&omap_port->lock);
648 		}
649 	}
650 	spin_unlock_bh(&omap_port->lock);
651 	pm_runtime_put_autosuspend(omap_port->pdev);
652 }
653 
654 static void ssi_cleanup_queues(struct hsi_client *cl)
655 {
656 	struct hsi_port *port = hsi_get_port(cl);
657 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
658 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
659 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
660 	struct hsi_msg *msg;
661 	unsigned int i;
662 	u32 rxbufstate = 0;
663 	u32 txbufstate = 0;
664 	u32 status = SSI_ERROROCCURED;
665 	u32 tmp;
666 
667 	ssi_flush_queue(&omap_port->brkqueue, cl);
668 	if (list_empty(&omap_port->brkqueue))
669 		status |= SSI_BREAKDETECTED;
670 
671 	for (i = 0; i < omap_port->channels; i++) {
672 		if (list_empty(&omap_port->txqueue[i]))
673 			continue;
674 		msg = list_first_entry(&omap_port->txqueue[i], struct hsi_msg,
675 									link);
676 		if ((msg->cl == cl) && (msg->status == HSI_STATUS_PROCEEDING)) {
677 			txbufstate |= (1 << i);
678 			status |= SSI_DATAACCEPT(i);
679 			/* Release the clocks writes, also GDD ones */
680 			pm_runtime_put_autosuspend(omap_port->pdev);
681 		}
682 		ssi_flush_queue(&omap_port->txqueue[i], cl);
683 	}
684 	for (i = 0; i < omap_port->channels; i++) {
685 		if (list_empty(&omap_port->rxqueue[i]))
686 			continue;
687 		msg = list_first_entry(&omap_port->rxqueue[i], struct hsi_msg,
688 									link);
689 		if ((msg->cl == cl) && (msg->status == HSI_STATUS_PROCEEDING)) {
690 			rxbufstate |= (1 << i);
691 			status |= SSI_DATAAVAILABLE(i);
692 		}
693 		ssi_flush_queue(&omap_port->rxqueue[i], cl);
694 		/* Check if we keep the error detection interrupt armed */
695 		if (!list_empty(&omap_port->rxqueue[i]))
696 			status &= ~SSI_ERROROCCURED;
697 	}
698 	/* Cleanup write buffers */
699 	tmp = readl(omap_port->sst_base + SSI_SST_BUFSTATE_REG);
700 	tmp &= ~txbufstate;
701 	writel_relaxed(tmp, omap_port->sst_base + SSI_SST_BUFSTATE_REG);
702 	/* Cleanup read buffers */
703 	tmp = readl(omap_port->ssr_base + SSI_SSR_BUFSTATE_REG);
704 	tmp &= ~rxbufstate;
705 	writel_relaxed(tmp, omap_port->ssr_base + SSI_SSR_BUFSTATE_REG);
706 	/* Disarm and ack pending interrupts */
707 	tmp = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
708 	tmp &= ~status;
709 	writel_relaxed(tmp, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
710 	writel_relaxed(status, omap_ssi->sys +
711 		SSI_MPU_STATUS_REG(port->num, 0));
712 }
713 
714 static void ssi_cleanup_gdd(struct hsi_controller *ssi, struct hsi_client *cl)
715 {
716 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
717 	struct hsi_port *port = hsi_get_port(cl);
718 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
719 	struct hsi_msg *msg;
720 	unsigned int i;
721 	u32 val = 0;
722 	u32 tmp;
723 
724 	for (i = 0; i < SSI_MAX_GDD_LCH; i++) {
725 		msg = omap_ssi->gdd_trn[i].msg;
726 		if ((!msg) || (msg->cl != cl))
727 			continue;
728 		writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
729 		val |= (1 << i);
730 		/*
731 		 * Clock references for write will be handled in
732 		 * ssi_cleanup_queues
733 		 */
734 		if (msg->ttype == HSI_MSG_READ) {
735 			pm_runtime_put_autosuspend(omap_port->pdev);
736 		}
737 		omap_ssi->gdd_trn[i].msg = NULL;
738 	}
739 	tmp = readl_relaxed(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
740 	tmp &= ~val;
741 	writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
742 	writel(val, omap_ssi->sys + SSI_GDD_MPU_IRQ_STATUS_REG);
743 }
744 
745 static int ssi_set_port_mode(struct omap_ssi_port *omap_port, u32 mode)
746 {
747 	writel(mode, omap_port->sst_base + SSI_SST_MODE_REG);
748 	writel(mode, omap_port->ssr_base + SSI_SSR_MODE_REG);
749 	/* OCP barrier */
750 	mode = readl(omap_port->ssr_base + SSI_SSR_MODE_REG);
751 
752 	return 0;
753 }
754 
755 static int ssi_release(struct hsi_client *cl)
756 {
757 	struct hsi_port *port = hsi_get_port(cl);
758 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
759 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
760 
761 	pm_runtime_get_sync(omap_port->pdev);
762 	spin_lock_bh(&omap_port->lock);
763 	/* Stop all the pending DMA requests for that client */
764 	ssi_cleanup_gdd(ssi, cl);
765 	/* Now cleanup all the queues */
766 	ssi_cleanup_queues(cl);
767 	/* If it is the last client of the port, do extra checks and cleanup */
768 	if (port->claimed <= 1) {
769 		/*
770 		 * Drop the clock reference for the incoming wake line
771 		 * if it is still kept high by the other side.
772 		 */
773 		if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags))
774 			pm_runtime_put_sync(omap_port->pdev);
775 		pm_runtime_get(omap_port->pdev);
776 		/* Stop any SSI TX/RX without a client */
777 		ssi_set_port_mode(omap_port, SSI_MODE_SLEEP);
778 		omap_port->sst.mode = SSI_MODE_SLEEP;
779 		omap_port->ssr.mode = SSI_MODE_SLEEP;
780 		pm_runtime_put(omap_port->pdev);
781 		WARN_ON(omap_port->wk_refcount != 0);
782 	}
783 	spin_unlock_bh(&omap_port->lock);
784 	pm_runtime_put_sync(omap_port->pdev);
785 
786 	return 0;
787 }
788 
789 
790 
791 static void ssi_error(struct hsi_port *port)
792 {
793 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
794 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
795 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
796 	struct hsi_msg *msg;
797 	unsigned int i;
798 	u32 err;
799 	u32 val;
800 	u32 tmp;
801 
802 	/* ACK error */
803 	err = readl(omap_port->ssr_base + SSI_SSR_ERROR_REG);
804 	dev_err(&port->device, "SSI error: 0x%02x\n", err);
805 	if (!err) {
806 		dev_dbg(&port->device, "spurious SSI error ignored!\n");
807 		return;
808 	}
809 	spin_lock(&omap_ssi->lock);
810 	/* Cancel all GDD read transfers */
811 	for (i = 0, val = 0; i < SSI_MAX_GDD_LCH; i++) {
812 		msg = omap_ssi->gdd_trn[i].msg;
813 		if ((msg) && (msg->ttype == HSI_MSG_READ)) {
814 			writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
815 			val |= (1 << i);
816 			omap_ssi->gdd_trn[i].msg = NULL;
817 		}
818 	}
819 	tmp = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
820 	tmp &= ~val;
821 	writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
822 	spin_unlock(&omap_ssi->lock);
823 	/* Cancel all PIO read transfers */
824 	spin_lock(&omap_port->lock);
825 	tmp = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
826 	tmp &= 0xfeff00ff; /* Disable error & all dataavailable interrupts */
827 	writel_relaxed(tmp, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
828 	/* ACK error */
829 	writel_relaxed(err, omap_port->ssr_base + SSI_SSR_ERRORACK_REG);
830 	writel_relaxed(SSI_ERROROCCURED,
831 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
832 	/* Signal the error all current pending read requests */
833 	for (i = 0; i < omap_port->channels; i++) {
834 		if (list_empty(&omap_port->rxqueue[i]))
835 			continue;
836 		msg = list_first_entry(&omap_port->rxqueue[i], struct hsi_msg,
837 									link);
838 		list_del(&msg->link);
839 		msg->status = HSI_STATUS_ERROR;
840 		spin_unlock(&omap_port->lock);
841 		msg->complete(msg);
842 		/* Now restart queued reads if any */
843 		ssi_transfer(omap_port, &omap_port->rxqueue[i]);
844 		spin_lock(&omap_port->lock);
845 	}
846 	spin_unlock(&omap_port->lock);
847 }
848 
849 static void ssi_break_complete(struct hsi_port *port)
850 {
851 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
852 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
853 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
854 	struct hsi_msg *msg;
855 	struct hsi_msg *tmp;
856 	u32 val;
857 
858 	dev_dbg(&port->device, "HWBREAK received\n");
859 
860 	spin_lock(&omap_port->lock);
861 	val = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
862 	val &= ~SSI_BREAKDETECTED;
863 	writel_relaxed(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
864 	writel_relaxed(0, omap_port->ssr_base + SSI_SSR_BREAK_REG);
865 	writel(SSI_BREAKDETECTED,
866 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
867 	spin_unlock(&omap_port->lock);
868 
869 	list_for_each_entry_safe(msg, tmp, &omap_port->brkqueue, link) {
870 		msg->status = HSI_STATUS_COMPLETED;
871 		spin_lock(&omap_port->lock);
872 		list_del(&msg->link);
873 		spin_unlock(&omap_port->lock);
874 		msg->complete(msg);
875 	}
876 
877 }
878 
879 static void ssi_pio_complete(struct hsi_port *port, struct list_head *queue)
880 {
881 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
882 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
883 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
884 	struct hsi_msg *msg;
885 	u32 *buf;
886 	u32 reg;
887 	u32 val;
888 
889 	spin_lock_bh(&omap_port->lock);
890 	msg = list_first_entry(queue, struct hsi_msg, link);
891 	if ((!msg->sgt.nents) || (!msg->sgt.sgl->length)) {
892 		msg->actual_len = 0;
893 		msg->status = HSI_STATUS_PENDING;
894 	}
895 	if (msg->ttype == HSI_MSG_WRITE)
896 		val = SSI_DATAACCEPT(msg->channel);
897 	else
898 		val = SSI_DATAAVAILABLE(msg->channel);
899 	if (msg->status == HSI_STATUS_PROCEEDING) {
900 		buf = sg_virt(msg->sgt.sgl) + msg->actual_len;
901 		if (msg->ttype == HSI_MSG_WRITE)
902 			writel(*buf, omap_port->sst_base +
903 					SSI_SST_BUFFER_CH_REG(msg->channel));
904 		 else
905 			*buf = readl(omap_port->ssr_base +
906 					SSI_SSR_BUFFER_CH_REG(msg->channel));
907 		dev_dbg(&port->device, "ch %d ttype %d 0x%08x\n", msg->channel,
908 							msg->ttype, *buf);
909 		msg->actual_len += sizeof(*buf);
910 		if (msg->actual_len >= msg->sgt.sgl->length)
911 			msg->status = HSI_STATUS_COMPLETED;
912 		/*
913 		 * Wait for the last written frame to be really sent before
914 		 * we call the complete callback
915 		 */
916 		if ((msg->status == HSI_STATUS_PROCEEDING) ||
917 				((msg->status == HSI_STATUS_COMPLETED) &&
918 					(msg->ttype == HSI_MSG_WRITE))) {
919 			writel(val, omap_ssi->sys +
920 					SSI_MPU_STATUS_REG(port->num, 0));
921 			spin_unlock_bh(&omap_port->lock);
922 
923 			return;
924 		}
925 
926 	}
927 	/* Transfer completed at this point */
928 	reg = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
929 	if (msg->ttype == HSI_MSG_WRITE) {
930 		/* Release clocks for write transfer */
931 		pm_runtime_put_autosuspend(omap_port->pdev);
932 	}
933 	reg &= ~val;
934 	writel_relaxed(reg, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
935 	writel_relaxed(val, omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
936 	list_del(&msg->link);
937 	spin_unlock_bh(&omap_port->lock);
938 	msg->complete(msg);
939 	ssi_transfer(omap_port, queue);
940 }
941 
942 static irqreturn_t ssi_pio_thread(int irq, void *ssi_port)
943 {
944 	struct hsi_port *port = (struct hsi_port *)ssi_port;
945 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
946 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
947 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
948 	void __iomem *sys = omap_ssi->sys;
949 	unsigned int ch;
950 	u32 status_reg;
951 
952 	pm_runtime_get_sync(omap_port->pdev);
953 
954 	do {
955 		status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
956 		status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
957 
958 		for (ch = 0; ch < omap_port->channels; ch++) {
959 			if (status_reg & SSI_DATAACCEPT(ch))
960 				ssi_pio_complete(port, &omap_port->txqueue[ch]);
961 			if (status_reg & SSI_DATAAVAILABLE(ch))
962 				ssi_pio_complete(port, &omap_port->rxqueue[ch]);
963 		}
964 		if (status_reg & SSI_BREAKDETECTED)
965 			ssi_break_complete(port);
966 		if (status_reg & SSI_ERROROCCURED)
967 			ssi_error(port);
968 
969 		status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
970 		status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
971 
972 		/* TODO: sleep if we retry? */
973 	} while (status_reg);
974 
975 	pm_runtime_put_autosuspend(omap_port->pdev);
976 
977 	return IRQ_HANDLED;
978 }
979 
980 static irqreturn_t ssi_wake_thread(int irq __maybe_unused, void *ssi_port)
981 {
982 	struct hsi_port *port = (struct hsi_port *)ssi_port;
983 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
984 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
985 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
986 
987 	if (ssi_wakein(port)) {
988 		/**
989 		 * We can have a quick High-Low-High transition in the line.
990 		 * In such a case if we have long interrupt latencies,
991 		 * we can miss the low event or get twice a high event.
992 		 * This workaround will avoid breaking the clock reference
993 		 * count when such a situation ocurrs.
994 		 */
995 		if (!test_and_set_bit(SSI_WAKE_EN, &omap_port->flags))
996 			pm_runtime_get_sync(omap_port->pdev);
997 		dev_dbg(&ssi->device, "Wake in high\n");
998 		if (omap_port->wktest) { /* FIXME: HACK ! To be removed */
999 			writel(SSI_WAKE(0),
1000 				omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
1001 		}
1002 		hsi_event(port, HSI_EVENT_START_RX);
1003 	} else {
1004 		dev_dbg(&ssi->device, "Wake in low\n");
1005 		if (omap_port->wktest) { /* FIXME: HACK ! To be removed */
1006 			writel(SSI_WAKE(0),
1007 				omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
1008 		}
1009 		hsi_event(port, HSI_EVENT_STOP_RX);
1010 		if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags)) {
1011 			pm_runtime_put_autosuspend(omap_port->pdev);
1012 		}
1013 	}
1014 
1015 	return IRQ_HANDLED;
1016 }
1017 
1018 static int ssi_port_irq(struct hsi_port *port, struct platform_device *pd)
1019 {
1020 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1021 	int err;
1022 
1023 	err = platform_get_irq(pd, 0);
1024 	if (err < 0)
1025 		return err;
1026 	omap_port->irq = err;
1027 	err = devm_request_threaded_irq(&port->device, omap_port->irq, NULL,
1028 				ssi_pio_thread, IRQF_ONESHOT, "SSI PORT", port);
1029 	if (err < 0)
1030 		dev_err(&port->device, "Request IRQ %d failed (%d)\n",
1031 							omap_port->irq, err);
1032 	return err;
1033 }
1034 
1035 static int ssi_wake_irq(struct hsi_port *port, struct platform_device *pd)
1036 {
1037 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1038 	int cawake_irq;
1039 	int err;
1040 
1041 	if (!omap_port->wake_gpio) {
1042 		omap_port->wake_irq = -1;
1043 		return 0;
1044 	}
1045 
1046 	cawake_irq = gpiod_to_irq(omap_port->wake_gpio);
1047 	omap_port->wake_irq = cawake_irq;
1048 
1049 	err = devm_request_threaded_irq(&port->device, cawake_irq, NULL,
1050 		ssi_wake_thread,
1051 		IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1052 		"SSI cawake", port);
1053 	if (err < 0)
1054 		dev_err(&port->device, "Request Wake in IRQ %d failed %d\n",
1055 						cawake_irq, err);
1056 	err = enable_irq_wake(cawake_irq);
1057 	if (err < 0)
1058 		dev_err(&port->device, "Enable wake on the wakeline in irq %d failed %d\n",
1059 			cawake_irq, err);
1060 
1061 	return err;
1062 }
1063 
1064 static void ssi_queues_init(struct omap_ssi_port *omap_port)
1065 {
1066 	unsigned int ch;
1067 
1068 	for (ch = 0; ch < SSI_MAX_CHANNELS; ch++) {
1069 		INIT_LIST_HEAD(&omap_port->txqueue[ch]);
1070 		INIT_LIST_HEAD(&omap_port->rxqueue[ch]);
1071 	}
1072 	INIT_LIST_HEAD(&omap_port->brkqueue);
1073 }
1074 
1075 static int ssi_port_get_iomem(struct platform_device *pd,
1076 		const char *name, void __iomem **pbase, dma_addr_t *phy)
1077 {
1078 	struct hsi_port *port = platform_get_drvdata(pd);
1079 	struct resource *mem;
1080 	struct resource *ioarea;
1081 	void __iomem *base;
1082 
1083 	mem = platform_get_resource_byname(pd, IORESOURCE_MEM, name);
1084 	if (!mem) {
1085 		dev_err(&pd->dev, "IO memory region missing (%s)\n", name);
1086 		return -ENXIO;
1087 	}
1088 	ioarea = devm_request_mem_region(&port->device, mem->start,
1089 					resource_size(mem), dev_name(&pd->dev));
1090 	if (!ioarea) {
1091 		dev_err(&pd->dev, "%s IO memory region request failed\n",
1092 								mem->name);
1093 		return -ENXIO;
1094 	}
1095 	base = devm_ioremap(&port->device, mem->start, resource_size(mem));
1096 	if (!base) {
1097 		dev_err(&pd->dev, "%s IO remap failed\n", mem->name);
1098 		return -ENXIO;
1099 	}
1100 	*pbase = base;
1101 
1102 	if (phy)
1103 		*phy = mem->start;
1104 
1105 	return 0;
1106 }
1107 
1108 static int ssi_port_probe(struct platform_device *pd)
1109 {
1110 	struct device_node *np = pd->dev.of_node;
1111 	struct hsi_port *port;
1112 	struct omap_ssi_port *omap_port;
1113 	struct hsi_controller *ssi = dev_get_drvdata(pd->dev.parent);
1114 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1115 	struct gpio_desc *cawake_gpio = NULL;
1116 	u32 port_id;
1117 	int err;
1118 
1119 	dev_dbg(&pd->dev, "init ssi port...\n");
1120 
1121 	if (!ssi->port || !omap_ssi->port) {
1122 		dev_err(&pd->dev, "ssi controller not initialized!\n");
1123 		err = -ENODEV;
1124 		goto error;
1125 	}
1126 
1127 	/* get id of first uninitialized port in controller */
1128 	for (port_id = 0; port_id < ssi->num_ports && omap_ssi->port[port_id];
1129 		port_id++)
1130 		;
1131 
1132 	if (port_id >= ssi->num_ports) {
1133 		dev_err(&pd->dev, "port id out of range!\n");
1134 		err = -ENODEV;
1135 		goto error;
1136 	}
1137 
1138 	port = ssi->port[port_id];
1139 
1140 	if (!np) {
1141 		dev_err(&pd->dev, "missing device tree data\n");
1142 		err = -EINVAL;
1143 		goto error;
1144 	}
1145 
1146 	cawake_gpio = devm_gpiod_get(&pd->dev, "ti,ssi-cawake", GPIOD_IN);
1147 	if (IS_ERR(cawake_gpio)) {
1148 		err = PTR_ERR(cawake_gpio);
1149 		dev_err(&pd->dev, "couldn't get cawake gpio (err=%d)!\n", err);
1150 		goto error;
1151 	}
1152 
1153 	omap_port = devm_kzalloc(&port->device, sizeof(*omap_port), GFP_KERNEL);
1154 	if (!omap_port) {
1155 		err = -ENOMEM;
1156 		goto error;
1157 	}
1158 	omap_port->wake_gpio = cawake_gpio;
1159 	omap_port->pdev = &pd->dev;
1160 	omap_port->port_id = port_id;
1161 
1162 	INIT_DEFERRABLE_WORK(&omap_port->errqueue_work, ssi_process_errqueue);
1163 	INIT_WORK(&omap_port->work, start_tx_work);
1164 
1165 	/* initialize HSI port */
1166 	port->async	= ssi_async;
1167 	port->setup	= ssi_setup;
1168 	port->flush	= ssi_flush;
1169 	port->start_tx	= ssi_start_tx;
1170 	port->stop_tx	= ssi_stop_tx;
1171 	port->release	= ssi_release;
1172 	hsi_port_set_drvdata(port, omap_port);
1173 	omap_ssi->port[port_id] = omap_port;
1174 
1175 	platform_set_drvdata(pd, port);
1176 
1177 	err = ssi_port_get_iomem(pd, "tx", &omap_port->sst_base,
1178 		&omap_port->sst_dma);
1179 	if (err < 0)
1180 		goto error;
1181 	err = ssi_port_get_iomem(pd, "rx", &omap_port->ssr_base,
1182 		&omap_port->ssr_dma);
1183 	if (err < 0)
1184 		goto error;
1185 
1186 	err = ssi_port_irq(port, pd);
1187 	if (err < 0)
1188 		goto error;
1189 	err = ssi_wake_irq(port, pd);
1190 	if (err < 0)
1191 		goto error;
1192 
1193 	ssi_queues_init(omap_port);
1194 	spin_lock_init(&omap_port->lock);
1195 	spin_lock_init(&omap_port->wk_lock);
1196 	omap_port->dev = &port->device;
1197 
1198 	pm_runtime_use_autosuspend(omap_port->pdev);
1199 	pm_runtime_set_autosuspend_delay(omap_port->pdev, 250);
1200 	pm_runtime_enable(omap_port->pdev);
1201 
1202 #ifdef CONFIG_DEBUG_FS
1203 	ssi_debug_add_port(omap_port, omap_ssi->dir);
1204 #endif
1205 
1206 	hsi_add_clients_from_dt(port, np);
1207 
1208 	dev_info(&pd->dev, "ssi port %u successfully initialized\n", port_id);
1209 
1210 	return 0;
1211 
1212 error:
1213 	return err;
1214 }
1215 
1216 static void ssi_port_remove(struct platform_device *pd)
1217 {
1218 	struct hsi_port *port = platform_get_drvdata(pd);
1219 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1220 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1221 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1222 
1223 #ifdef CONFIG_DEBUG_FS
1224 	ssi_debug_remove_port(port);
1225 #endif
1226 
1227 	cancel_delayed_work_sync(&omap_port->errqueue_work);
1228 
1229 	hsi_port_unregister_clients(port);
1230 
1231 	port->async	= hsi_dummy_msg;
1232 	port->setup	= hsi_dummy_cl;
1233 	port->flush	= hsi_dummy_cl;
1234 	port->start_tx	= hsi_dummy_cl;
1235 	port->stop_tx	= hsi_dummy_cl;
1236 	port->release	= hsi_dummy_cl;
1237 
1238 	omap_ssi->port[omap_port->port_id] = NULL;
1239 	platform_set_drvdata(pd, NULL);
1240 
1241 	pm_runtime_dont_use_autosuspend(&pd->dev);
1242 	pm_runtime_disable(&pd->dev);
1243 }
1244 
1245 static int ssi_restore_divisor(struct omap_ssi_port *omap_port)
1246 {
1247 	writel_relaxed(omap_port->sst.divisor,
1248 				omap_port->sst_base + SSI_SST_DIVISOR_REG);
1249 
1250 	return 0;
1251 }
1252 
1253 void omap_ssi_port_update_fclk(struct hsi_controller *ssi,
1254 			       struct omap_ssi_port *omap_port)
1255 {
1256 	/* update divisor */
1257 	u32 div = ssi_calculate_div(ssi);
1258 	omap_port->sst.divisor = div;
1259 	ssi_restore_divisor(omap_port);
1260 }
1261 
1262 #ifdef CONFIG_PM
1263 static int ssi_save_port_ctx(struct omap_ssi_port *omap_port)
1264 {
1265 	struct hsi_port *port = to_hsi_port(omap_port->dev);
1266 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1267 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1268 
1269 	omap_port->sys_mpu_enable = readl(omap_ssi->sys +
1270 					SSI_MPU_ENABLE_REG(port->num, 0));
1271 
1272 	return 0;
1273 }
1274 
1275 static int ssi_restore_port_ctx(struct omap_ssi_port *omap_port)
1276 {
1277 	struct hsi_port *port = to_hsi_port(omap_port->dev);
1278 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1279 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1280 	void __iomem	*base;
1281 
1282 	writel_relaxed(omap_port->sys_mpu_enable,
1283 			omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
1284 
1285 	/* SST context */
1286 	base = omap_port->sst_base;
1287 	writel_relaxed(omap_port->sst.frame_size, base + SSI_SST_FRAMESIZE_REG);
1288 	writel_relaxed(omap_port->sst.channels, base + SSI_SST_CHANNELS_REG);
1289 	writel_relaxed(omap_port->sst.arb_mode, base + SSI_SST_ARBMODE_REG);
1290 
1291 	/* SSR context */
1292 	base = omap_port->ssr_base;
1293 	writel_relaxed(omap_port->ssr.frame_size, base + SSI_SSR_FRAMESIZE_REG);
1294 	writel_relaxed(omap_port->ssr.channels, base + SSI_SSR_CHANNELS_REG);
1295 	writel_relaxed(omap_port->ssr.timeout, base + SSI_SSR_TIMEOUT_REG);
1296 
1297 	return 0;
1298 }
1299 
1300 static int ssi_restore_port_mode(struct omap_ssi_port *omap_port)
1301 {
1302 	u32 mode;
1303 
1304 	writel_relaxed(omap_port->sst.mode,
1305 				omap_port->sst_base + SSI_SST_MODE_REG);
1306 	writel_relaxed(omap_port->ssr.mode,
1307 				omap_port->ssr_base + SSI_SSR_MODE_REG);
1308 	/* OCP barrier */
1309 	mode = readl(omap_port->ssr_base + SSI_SSR_MODE_REG);
1310 
1311 	return 0;
1312 }
1313 
1314 static int omap_ssi_port_runtime_suspend(struct device *dev)
1315 {
1316 	struct hsi_port *port = dev_get_drvdata(dev);
1317 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1318 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1319 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1320 
1321 	dev_dbg(dev, "port runtime suspend!\n");
1322 
1323 	ssi_set_port_mode(omap_port, SSI_MODE_SLEEP);
1324 	if (omap_ssi->get_loss)
1325 		omap_port->loss_count =
1326 				omap_ssi->get_loss(ssi->device.parent);
1327 	ssi_save_port_ctx(omap_port);
1328 
1329 	return 0;
1330 }
1331 
1332 static int omap_ssi_port_runtime_resume(struct device *dev)
1333 {
1334 	struct hsi_port *port = dev_get_drvdata(dev);
1335 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1336 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1337 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1338 
1339 	dev_dbg(dev, "port runtime resume!\n");
1340 
1341 	if ((omap_ssi->get_loss) && (omap_port->loss_count ==
1342 				omap_ssi->get_loss(ssi->device.parent)))
1343 		goto mode; /* We always need to restore the mode & TX divisor */
1344 
1345 	ssi_restore_port_ctx(omap_port);
1346 
1347 mode:
1348 	ssi_restore_divisor(omap_port);
1349 	ssi_restore_port_mode(omap_port);
1350 
1351 	return 0;
1352 }
1353 
1354 static const struct dev_pm_ops omap_ssi_port_pm_ops = {
1355 	SET_RUNTIME_PM_OPS(omap_ssi_port_runtime_suspend,
1356 		omap_ssi_port_runtime_resume, NULL)
1357 };
1358 
1359 #define DEV_PM_OPS     (&omap_ssi_port_pm_ops)
1360 #else
1361 #define DEV_PM_OPS     NULL
1362 #endif
1363 
1364 
1365 #ifdef CONFIG_OF
1366 static const struct of_device_id omap_ssi_port_of_match[] = {
1367 	{ .compatible = "ti,omap3-ssi-port", },
1368 	{},
1369 };
1370 MODULE_DEVICE_TABLE(of, omap_ssi_port_of_match);
1371 #else
1372 #define omap_ssi_port_of_match NULL
1373 #endif
1374 
1375 struct platform_driver ssi_port_pdriver = {
1376 	.probe = ssi_port_probe,
1377 	.remove = ssi_port_remove,
1378 	.driver	= {
1379 		.name	= "omap_ssi_port",
1380 		.of_match_table = omap_ssi_port_of_match,
1381 		.pm	= DEV_PM_OPS,
1382 	},
1383 };
1384