xref: /linux/drivers/hsi/controllers/omap_ssi_port.c (revision 53597deca0e38c30e6cd4ba2114fa42d2bcd85bb)
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 	int err = 0;
456 
457 	pm_runtime_get_sync(omap_port->pdev);
458 	spin_lock_bh(&omap_port->lock);
459 	if (cl->tx_cfg.speed)
460 		omap_ssi->max_speed = cl->tx_cfg.speed;
461 	div = ssi_calculate_div(ssi);
462 	if (div > SSI_MAX_DIVISOR) {
463 		dev_err(&cl->device, "Invalid TX speed %d Mb/s (div %d)\n",
464 						cl->tx_cfg.speed, div);
465 		err = -EINVAL;
466 		goto out;
467 	}
468 	/* Set TX/RX module to sleep to stop TX/RX during cfg update */
469 	writel_relaxed(SSI_MODE_SLEEP, sst + SSI_SST_MODE_REG);
470 	writel_relaxed(SSI_MODE_SLEEP, ssr + SSI_SSR_MODE_REG);
471 	/* Flush posted write */
472 	readl(ssr + SSI_SSR_MODE_REG);
473 	/* TX */
474 	writel_relaxed(31, sst + SSI_SST_FRAMESIZE_REG);
475 	writel_relaxed(div, sst + SSI_SST_DIVISOR_REG);
476 	writel_relaxed(cl->tx_cfg.num_hw_channels, sst + SSI_SST_CHANNELS_REG);
477 	writel_relaxed(cl->tx_cfg.arb_mode, sst + SSI_SST_ARBMODE_REG);
478 	writel_relaxed(cl->tx_cfg.mode, sst + SSI_SST_MODE_REG);
479 	/* RX */
480 	writel_relaxed(31, ssr + SSI_SSR_FRAMESIZE_REG);
481 	writel_relaxed(cl->rx_cfg.num_hw_channels, ssr + SSI_SSR_CHANNELS_REG);
482 	writel_relaxed(0, ssr + SSI_SSR_TIMEOUT_REG);
483 	/* Cleanup the break queue if we leave FRAME mode */
484 	if ((omap_port->ssr.mode == SSI_MODE_FRAME) &&
485 		(cl->rx_cfg.mode != SSI_MODE_FRAME))
486 		ssi_flush_queue(&omap_port->brkqueue, cl);
487 	writel_relaxed(cl->rx_cfg.mode, ssr + SSI_SSR_MODE_REG);
488 	omap_port->channels = max(cl->rx_cfg.num_hw_channels,
489 				  cl->tx_cfg.num_hw_channels);
490 	/* Shadow registering for OFF mode */
491 	/* SST */
492 	omap_port->sst.divisor = div;
493 	omap_port->sst.frame_size = 31;
494 	omap_port->sst.channels = cl->tx_cfg.num_hw_channels;
495 	omap_port->sst.arb_mode = cl->tx_cfg.arb_mode;
496 	omap_port->sst.mode = cl->tx_cfg.mode;
497 	/* SSR */
498 	omap_port->ssr.frame_size = 31;
499 	omap_port->ssr.timeout = 0;
500 	omap_port->ssr.channels = cl->rx_cfg.num_hw_channels;
501 	omap_port->ssr.mode = cl->rx_cfg.mode;
502 out:
503 	spin_unlock_bh(&omap_port->lock);
504 	pm_runtime_put_autosuspend(omap_port->pdev);
505 
506 	return err;
507 }
508 
509 static int ssi_flush(struct hsi_client *cl)
510 {
511 	struct hsi_port *port = hsi_get_port(cl);
512 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
513 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
514 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
515 	struct hsi_msg *msg;
516 	void __iomem *sst = omap_port->sst_base;
517 	void __iomem *ssr = omap_port->ssr_base;
518 	unsigned int i;
519 	u32 err;
520 
521 	pm_runtime_get_sync(omap_port->pdev);
522 	spin_lock_bh(&omap_port->lock);
523 
524 	/* stop all ssi communication */
525 	pinctrl_pm_select_idle_state(omap_port->pdev);
526 	udelay(1); /* wait for racing frames */
527 
528 	/* Stop all DMA transfers */
529 	for (i = 0; i < SSI_MAX_GDD_LCH; i++) {
530 		msg = omap_ssi->gdd_trn[i].msg;
531 		if (!msg || (port != hsi_get_port(msg->cl)))
532 			continue;
533 		writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
534 		if (msg->ttype == HSI_MSG_READ)
535 			pm_runtime_put_autosuspend(omap_port->pdev);
536 		omap_ssi->gdd_trn[i].msg = NULL;
537 	}
538 	/* Flush all SST buffers */
539 	writel_relaxed(0, sst + SSI_SST_BUFSTATE_REG);
540 	writel_relaxed(0, sst + SSI_SST_TXSTATE_REG);
541 	/* Flush all SSR buffers */
542 	writel_relaxed(0, ssr + SSI_SSR_RXSTATE_REG);
543 	writel_relaxed(0, ssr + SSI_SSR_BUFSTATE_REG);
544 	/* Flush all errors */
545 	err = readl(ssr + SSI_SSR_ERROR_REG);
546 	writel_relaxed(err, ssr + SSI_SSR_ERRORACK_REG);
547 	/* Flush break */
548 	writel_relaxed(0, ssr + SSI_SSR_BREAK_REG);
549 	/* Clear interrupts */
550 	writel_relaxed(0, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
551 	writel_relaxed(0xffffff00,
552 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
553 	writel_relaxed(0, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
554 	writel(0xff, omap_ssi->sys + SSI_GDD_MPU_IRQ_STATUS_REG);
555 	/* Dequeue all pending requests */
556 	for (i = 0; i < omap_port->channels; i++) {
557 		/* Release write clocks */
558 		if (!list_empty(&omap_port->txqueue[i]))
559 			pm_runtime_put_autosuspend(omap_port->pdev);
560 		ssi_flush_queue(&omap_port->txqueue[i], NULL);
561 		ssi_flush_queue(&omap_port->rxqueue[i], NULL);
562 	}
563 	ssi_flush_queue(&omap_port->brkqueue, NULL);
564 
565 	/* Resume SSI communication */
566 	pinctrl_pm_select_default_state(omap_port->pdev);
567 
568 	spin_unlock_bh(&omap_port->lock);
569 	pm_runtime_put_autosuspend(omap_port->pdev);
570 
571 	return 0;
572 }
573 
574 static void start_tx_work(struct work_struct *work)
575 {
576 	struct omap_ssi_port *omap_port =
577 				container_of(work, struct omap_ssi_port, work);
578 	struct hsi_port *port = to_hsi_port(omap_port->dev);
579 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
580 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
581 
582 	pm_runtime_get_sync(omap_port->pdev); /* Grab clocks */
583 	writel(SSI_WAKE(0), omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
584 }
585 
586 static int ssi_start_tx(struct hsi_client *cl)
587 {
588 	struct hsi_port *port = hsi_get_port(cl);
589 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
590 
591 	dev_dbg(&port->device, "Wake out high %d\n", omap_port->wk_refcount);
592 
593 	spin_lock_bh(&omap_port->wk_lock);
594 	if (omap_port->wk_refcount++) {
595 		spin_unlock_bh(&omap_port->wk_lock);
596 		return 0;
597 	}
598 	spin_unlock_bh(&omap_port->wk_lock);
599 
600 	schedule_work(&omap_port->work);
601 
602 	return 0;
603 }
604 
605 static int ssi_stop_tx(struct hsi_client *cl)
606 {
607 	struct hsi_port *port = hsi_get_port(cl);
608 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
609 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
610 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
611 
612 	dev_dbg(&port->device, "Wake out low %d\n", omap_port->wk_refcount);
613 
614 	spin_lock_bh(&omap_port->wk_lock);
615 	BUG_ON(!omap_port->wk_refcount);
616 	if (--omap_port->wk_refcount) {
617 		spin_unlock_bh(&omap_port->wk_lock);
618 		return 0;
619 	}
620 	writel(SSI_WAKE(0), omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
621 	spin_unlock_bh(&omap_port->wk_lock);
622 
623 	pm_runtime_put_autosuspend(omap_port->pdev); /* Release clocks */
624 
625 
626 	return 0;
627 }
628 
629 static void ssi_transfer(struct omap_ssi_port *omap_port,
630 							struct list_head *queue)
631 {
632 	struct hsi_msg *msg;
633 	int err = -1;
634 
635 	pm_runtime_get(omap_port->pdev);
636 	spin_lock_bh(&omap_port->lock);
637 	while (err < 0) {
638 		err = ssi_start_transfer(queue);
639 		if (err < 0) {
640 			msg = list_first_entry(queue, struct hsi_msg, link);
641 			msg->status = HSI_STATUS_ERROR;
642 			msg->actual_len = 0;
643 			list_del(&msg->link);
644 			spin_unlock_bh(&omap_port->lock);
645 			msg->complete(msg);
646 			spin_lock_bh(&omap_port->lock);
647 		}
648 	}
649 	spin_unlock_bh(&omap_port->lock);
650 	pm_runtime_put_autosuspend(omap_port->pdev);
651 }
652 
653 static void ssi_cleanup_queues(struct hsi_client *cl)
654 {
655 	struct hsi_port *port = hsi_get_port(cl);
656 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
657 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
658 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
659 	struct hsi_msg *msg;
660 	unsigned int i;
661 	u32 rxbufstate = 0;
662 	u32 txbufstate = 0;
663 	u32 status = SSI_ERROROCCURED;
664 	u32 tmp;
665 
666 	ssi_flush_queue(&omap_port->brkqueue, cl);
667 	if (list_empty(&omap_port->brkqueue))
668 		status |= SSI_BREAKDETECTED;
669 
670 	for (i = 0; i < omap_port->channels; i++) {
671 		if (list_empty(&omap_port->txqueue[i]))
672 			continue;
673 		msg = list_first_entry(&omap_port->txqueue[i], struct hsi_msg,
674 									link);
675 		if ((msg->cl == cl) && (msg->status == HSI_STATUS_PROCEEDING)) {
676 			txbufstate |= (1 << i);
677 			status |= SSI_DATAACCEPT(i);
678 			/* Release the clocks writes, also GDD ones */
679 			pm_runtime_put_autosuspend(omap_port->pdev);
680 		}
681 		ssi_flush_queue(&omap_port->txqueue[i], cl);
682 	}
683 	for (i = 0; i < omap_port->channels; i++) {
684 		if (list_empty(&omap_port->rxqueue[i]))
685 			continue;
686 		msg = list_first_entry(&omap_port->rxqueue[i], struct hsi_msg,
687 									link);
688 		if ((msg->cl == cl) && (msg->status == HSI_STATUS_PROCEEDING)) {
689 			rxbufstate |= (1 << i);
690 			status |= SSI_DATAAVAILABLE(i);
691 		}
692 		ssi_flush_queue(&omap_port->rxqueue[i], cl);
693 		/* Check if we keep the error detection interrupt armed */
694 		if (!list_empty(&omap_port->rxqueue[i]))
695 			status &= ~SSI_ERROROCCURED;
696 	}
697 	/* Cleanup write buffers */
698 	tmp = readl(omap_port->sst_base + SSI_SST_BUFSTATE_REG);
699 	tmp &= ~txbufstate;
700 	writel_relaxed(tmp, omap_port->sst_base + SSI_SST_BUFSTATE_REG);
701 	/* Cleanup read buffers */
702 	tmp = readl(omap_port->ssr_base + SSI_SSR_BUFSTATE_REG);
703 	tmp &= ~rxbufstate;
704 	writel_relaxed(tmp, omap_port->ssr_base + SSI_SSR_BUFSTATE_REG);
705 	/* Disarm and ack pending interrupts */
706 	tmp = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
707 	tmp &= ~status;
708 	writel_relaxed(tmp, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
709 	writel_relaxed(status, omap_ssi->sys +
710 		SSI_MPU_STATUS_REG(port->num, 0));
711 }
712 
713 static void ssi_cleanup_gdd(struct hsi_controller *ssi, struct hsi_client *cl)
714 {
715 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
716 	struct hsi_port *port = hsi_get_port(cl);
717 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
718 	struct hsi_msg *msg;
719 	unsigned int i;
720 	u32 val = 0;
721 	u32 tmp;
722 
723 	for (i = 0; i < SSI_MAX_GDD_LCH; i++) {
724 		msg = omap_ssi->gdd_trn[i].msg;
725 		if ((!msg) || (msg->cl != cl))
726 			continue;
727 		writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
728 		val |= (1 << i);
729 		/*
730 		 * Clock references for write will be handled in
731 		 * ssi_cleanup_queues
732 		 */
733 		if (msg->ttype == HSI_MSG_READ) {
734 			pm_runtime_put_autosuspend(omap_port->pdev);
735 		}
736 		omap_ssi->gdd_trn[i].msg = NULL;
737 	}
738 	tmp = readl_relaxed(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
739 	tmp &= ~val;
740 	writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
741 	writel(val, omap_ssi->sys + SSI_GDD_MPU_IRQ_STATUS_REG);
742 }
743 
744 static int ssi_set_port_mode(struct omap_ssi_port *omap_port, u32 mode)
745 {
746 	writel(mode, omap_port->sst_base + SSI_SST_MODE_REG);
747 	writel(mode, omap_port->ssr_base + SSI_SSR_MODE_REG);
748 	/* OCP barrier */
749 	mode = readl(omap_port->ssr_base + SSI_SSR_MODE_REG);
750 
751 	return 0;
752 }
753 
754 static int ssi_release(struct hsi_client *cl)
755 {
756 	struct hsi_port *port = hsi_get_port(cl);
757 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
758 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
759 
760 	pm_runtime_get_sync(omap_port->pdev);
761 	spin_lock_bh(&omap_port->lock);
762 	/* Stop all the pending DMA requests for that client */
763 	ssi_cleanup_gdd(ssi, cl);
764 	/* Now cleanup all the queues */
765 	ssi_cleanup_queues(cl);
766 	/* If it is the last client of the port, do extra checks and cleanup */
767 	if (port->claimed <= 1) {
768 		/*
769 		 * Drop the clock reference for the incoming wake line
770 		 * if it is still kept high by the other side.
771 		 */
772 		if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags))
773 			pm_runtime_put_sync(omap_port->pdev);
774 		pm_runtime_get(omap_port->pdev);
775 		/* Stop any SSI TX/RX without a client */
776 		ssi_set_port_mode(omap_port, SSI_MODE_SLEEP);
777 		omap_port->sst.mode = SSI_MODE_SLEEP;
778 		omap_port->ssr.mode = SSI_MODE_SLEEP;
779 		pm_runtime_put(omap_port->pdev);
780 		WARN_ON(omap_port->wk_refcount != 0);
781 	}
782 	spin_unlock_bh(&omap_port->lock);
783 	pm_runtime_put_sync(omap_port->pdev);
784 
785 	return 0;
786 }
787 
788 
789 
790 static void ssi_error(struct hsi_port *port)
791 {
792 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
793 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
794 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
795 	struct hsi_msg *msg;
796 	unsigned int i;
797 	u32 err;
798 	u32 val;
799 	u32 tmp;
800 
801 	/* ACK error */
802 	err = readl(omap_port->ssr_base + SSI_SSR_ERROR_REG);
803 	dev_err(&port->device, "SSI error: 0x%02x\n", err);
804 	if (!err) {
805 		dev_dbg(&port->device, "spurious SSI error ignored!\n");
806 		return;
807 	}
808 	spin_lock(&omap_ssi->lock);
809 	/* Cancel all GDD read transfers */
810 	for (i = 0, val = 0; i < SSI_MAX_GDD_LCH; i++) {
811 		msg = omap_ssi->gdd_trn[i].msg;
812 		if ((msg) && (msg->ttype == HSI_MSG_READ)) {
813 			writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i));
814 			val |= (1 << i);
815 			omap_ssi->gdd_trn[i].msg = NULL;
816 		}
817 	}
818 	tmp = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
819 	tmp &= ~val;
820 	writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
821 	spin_unlock(&omap_ssi->lock);
822 	/* Cancel all PIO read transfers */
823 	spin_lock(&omap_port->lock);
824 	tmp = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
825 	tmp &= 0xfeff00ff; /* Disable error & all dataavailable interrupts */
826 	writel_relaxed(tmp, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
827 	/* ACK error */
828 	writel_relaxed(err, omap_port->ssr_base + SSI_SSR_ERRORACK_REG);
829 	writel_relaxed(SSI_ERROROCCURED,
830 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
831 	/* Signal the error all current pending read requests */
832 	for (i = 0; i < omap_port->channels; i++) {
833 		if (list_empty(&omap_port->rxqueue[i]))
834 			continue;
835 		msg = list_first_entry(&omap_port->rxqueue[i], struct hsi_msg,
836 									link);
837 		list_del(&msg->link);
838 		msg->status = HSI_STATUS_ERROR;
839 		spin_unlock(&omap_port->lock);
840 		msg->complete(msg);
841 		/* Now restart queued reads if any */
842 		ssi_transfer(omap_port, &omap_port->rxqueue[i]);
843 		spin_lock(&omap_port->lock);
844 	}
845 	spin_unlock(&omap_port->lock);
846 }
847 
848 static void ssi_break_complete(struct hsi_port *port)
849 {
850 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
851 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
852 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
853 	struct hsi_msg *msg;
854 	struct hsi_msg *tmp;
855 	u32 val;
856 
857 	dev_dbg(&port->device, "HWBREAK received\n");
858 
859 	spin_lock(&omap_port->lock);
860 	val = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
861 	val &= ~SSI_BREAKDETECTED;
862 	writel_relaxed(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
863 	writel_relaxed(0, omap_port->ssr_base + SSI_SSR_BREAK_REG);
864 	writel(SSI_BREAKDETECTED,
865 			omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
866 	spin_unlock(&omap_port->lock);
867 
868 	list_for_each_entry_safe(msg, tmp, &omap_port->brkqueue, link) {
869 		msg->status = HSI_STATUS_COMPLETED;
870 		spin_lock(&omap_port->lock);
871 		list_del(&msg->link);
872 		spin_unlock(&omap_port->lock);
873 		msg->complete(msg);
874 	}
875 
876 }
877 
878 static void ssi_pio_complete(struct hsi_port *port, struct list_head *queue)
879 {
880 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
881 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
882 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
883 	struct hsi_msg *msg;
884 	u32 *buf;
885 	u32 reg;
886 	u32 val;
887 
888 	spin_lock_bh(&omap_port->lock);
889 	msg = list_first_entry(queue, struct hsi_msg, link);
890 	if ((!msg->sgt.nents) || (!msg->sgt.sgl->length)) {
891 		msg->actual_len = 0;
892 		msg->status = HSI_STATUS_PENDING;
893 	}
894 	if (msg->ttype == HSI_MSG_WRITE)
895 		val = SSI_DATAACCEPT(msg->channel);
896 	else
897 		val = SSI_DATAAVAILABLE(msg->channel);
898 	if (msg->status == HSI_STATUS_PROCEEDING) {
899 		buf = sg_virt(msg->sgt.sgl) + msg->actual_len;
900 		if (msg->ttype == HSI_MSG_WRITE)
901 			writel(*buf, omap_port->sst_base +
902 					SSI_SST_BUFFER_CH_REG(msg->channel));
903 		 else
904 			*buf = readl(omap_port->ssr_base +
905 					SSI_SSR_BUFFER_CH_REG(msg->channel));
906 		dev_dbg(&port->device, "ch %d ttype %d 0x%08x\n", msg->channel,
907 							msg->ttype, *buf);
908 		msg->actual_len += sizeof(*buf);
909 		if (msg->actual_len >= msg->sgt.sgl->length)
910 			msg->status = HSI_STATUS_COMPLETED;
911 		/*
912 		 * Wait for the last written frame to be really sent before
913 		 * we call the complete callback
914 		 */
915 		if ((msg->status == HSI_STATUS_PROCEEDING) ||
916 				((msg->status == HSI_STATUS_COMPLETED) &&
917 					(msg->ttype == HSI_MSG_WRITE))) {
918 			writel(val, omap_ssi->sys +
919 					SSI_MPU_STATUS_REG(port->num, 0));
920 			spin_unlock_bh(&omap_port->lock);
921 
922 			return;
923 		}
924 
925 	}
926 	/* Transfer completed at this point */
927 	reg = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
928 	if (msg->ttype == HSI_MSG_WRITE) {
929 		/* Release clocks for write transfer */
930 		pm_runtime_put_autosuspend(omap_port->pdev);
931 	}
932 	reg &= ~val;
933 	writel_relaxed(reg, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
934 	writel_relaxed(val, omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0));
935 	list_del(&msg->link);
936 	spin_unlock_bh(&omap_port->lock);
937 	msg->complete(msg);
938 	ssi_transfer(omap_port, queue);
939 }
940 
941 static irqreturn_t ssi_pio_thread(int irq, void *ssi_port)
942 {
943 	struct hsi_port *port = (struct hsi_port *)ssi_port;
944 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
945 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
946 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
947 	void __iomem *sys = omap_ssi->sys;
948 	unsigned int ch;
949 	u32 status_reg;
950 
951 	pm_runtime_get_sync(omap_port->pdev);
952 
953 	do {
954 		status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
955 		status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
956 
957 		for (ch = 0; ch < omap_port->channels; ch++) {
958 			if (status_reg & SSI_DATAACCEPT(ch))
959 				ssi_pio_complete(port, &omap_port->txqueue[ch]);
960 			if (status_reg & SSI_DATAAVAILABLE(ch))
961 				ssi_pio_complete(port, &omap_port->rxqueue[ch]);
962 		}
963 		if (status_reg & SSI_BREAKDETECTED)
964 			ssi_break_complete(port);
965 		if (status_reg & SSI_ERROROCCURED)
966 			ssi_error(port);
967 
968 		status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0));
969 		status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0));
970 
971 		/* TODO: sleep if we retry? */
972 	} while (status_reg);
973 
974 	pm_runtime_put_autosuspend(omap_port->pdev);
975 
976 	return IRQ_HANDLED;
977 }
978 
979 static irqreturn_t ssi_wake_thread(int irq __maybe_unused, void *ssi_port)
980 {
981 	struct hsi_port *port = (struct hsi_port *)ssi_port;
982 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
983 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
984 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
985 
986 	if (ssi_wakein(port)) {
987 		/**
988 		 * We can have a quick High-Low-High transition in the line.
989 		 * In such a case if we have long interrupt latencies,
990 		 * we can miss the low event or get twice a high event.
991 		 * This workaround will avoid breaking the clock reference
992 		 * count when such a situation ocurrs.
993 		 */
994 		if (!test_and_set_bit(SSI_WAKE_EN, &omap_port->flags))
995 			pm_runtime_get_sync(omap_port->pdev);
996 		dev_dbg(&ssi->device, "Wake in high\n");
997 		if (omap_port->wktest) { /* FIXME: HACK ! To be removed */
998 			writel(SSI_WAKE(0),
999 				omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
1000 		}
1001 		hsi_event(port, HSI_EVENT_START_RX);
1002 	} else {
1003 		dev_dbg(&ssi->device, "Wake in low\n");
1004 		if (omap_port->wktest) { /* FIXME: HACK ! To be removed */
1005 			writel(SSI_WAKE(0),
1006 				omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num));
1007 		}
1008 		hsi_event(port, HSI_EVENT_STOP_RX);
1009 		if (test_and_clear_bit(SSI_WAKE_EN, &omap_port->flags)) {
1010 			pm_runtime_put_autosuspend(omap_port->pdev);
1011 		}
1012 	}
1013 
1014 	return IRQ_HANDLED;
1015 }
1016 
1017 static int ssi_port_irq(struct hsi_port *port, struct platform_device *pd)
1018 {
1019 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1020 	int err;
1021 
1022 	err = platform_get_irq(pd, 0);
1023 	if (err < 0)
1024 		return err;
1025 	omap_port->irq = err;
1026 	err = devm_request_threaded_irq(&port->device, omap_port->irq, NULL,
1027 				ssi_pio_thread, IRQF_ONESHOT, "SSI PORT", port);
1028 	if (err < 0)
1029 		dev_err(&port->device, "Request IRQ %d failed (%d)\n",
1030 							omap_port->irq, err);
1031 	return err;
1032 }
1033 
1034 static int ssi_wake_irq(struct hsi_port *port, struct platform_device *pd)
1035 {
1036 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1037 	int cawake_irq;
1038 	int err;
1039 
1040 	if (!omap_port->wake_gpio) {
1041 		omap_port->wake_irq = -1;
1042 		return 0;
1043 	}
1044 
1045 	cawake_irq = gpiod_to_irq(omap_port->wake_gpio);
1046 	omap_port->wake_irq = cawake_irq;
1047 
1048 	err = devm_request_threaded_irq(&port->device, cawake_irq, NULL,
1049 		ssi_wake_thread,
1050 		IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1051 		"SSI cawake", port);
1052 	if (err < 0)
1053 		dev_err(&port->device, "Request Wake in IRQ %d failed %d\n",
1054 						cawake_irq, err);
1055 	err = enable_irq_wake(cawake_irq);
1056 	if (err < 0)
1057 		dev_err(&port->device, "Enable wake on the wakeline in irq %d failed %d\n",
1058 			cawake_irq, err);
1059 
1060 	return err;
1061 }
1062 
1063 static void ssi_queues_init(struct omap_ssi_port *omap_port)
1064 {
1065 	unsigned int ch;
1066 
1067 	for (ch = 0; ch < SSI_MAX_CHANNELS; ch++) {
1068 		INIT_LIST_HEAD(&omap_port->txqueue[ch]);
1069 		INIT_LIST_HEAD(&omap_port->rxqueue[ch]);
1070 	}
1071 	INIT_LIST_HEAD(&omap_port->brkqueue);
1072 }
1073 
1074 static int ssi_port_get_iomem(struct platform_device *pd,
1075 		const char *name, void __iomem **pbase, dma_addr_t *phy)
1076 {
1077 	struct hsi_port *port = platform_get_drvdata(pd);
1078 	struct resource *mem;
1079 	struct resource *ioarea;
1080 	void __iomem *base;
1081 
1082 	mem = platform_get_resource_byname(pd, IORESOURCE_MEM, name);
1083 	if (!mem) {
1084 		dev_err(&pd->dev, "IO memory region missing (%s)\n", name);
1085 		return -ENXIO;
1086 	}
1087 	ioarea = devm_request_mem_region(&port->device, mem->start,
1088 					resource_size(mem), dev_name(&pd->dev));
1089 	if (!ioarea) {
1090 		dev_err(&pd->dev, "%s IO memory region request failed\n",
1091 								mem->name);
1092 		return -ENXIO;
1093 	}
1094 	base = devm_ioremap(&port->device, mem->start, resource_size(mem));
1095 	if (!base) {
1096 		dev_err(&pd->dev, "%s IO remap failed\n", mem->name);
1097 		return -ENXIO;
1098 	}
1099 	*pbase = base;
1100 
1101 	if (phy)
1102 		*phy = mem->start;
1103 
1104 	return 0;
1105 }
1106 
1107 static int ssi_port_probe(struct platform_device *pd)
1108 {
1109 	struct device_node *np = pd->dev.of_node;
1110 	struct hsi_port *port;
1111 	struct omap_ssi_port *omap_port;
1112 	struct hsi_controller *ssi = dev_get_drvdata(pd->dev.parent);
1113 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1114 	struct gpio_desc *cawake_gpio = NULL;
1115 	u32 port_id;
1116 	int err;
1117 
1118 	dev_dbg(&pd->dev, "init ssi port...\n");
1119 
1120 	if (!omap_ssi->port) {
1121 		dev_err(&pd->dev, "ssi controller not initialized!\n");
1122 		err = -ENODEV;
1123 		goto error;
1124 	}
1125 
1126 	/* get id of first uninitialized port in controller */
1127 	for (port_id = 0; port_id < ssi->num_ports && omap_ssi->port[port_id];
1128 		port_id++)
1129 		;
1130 
1131 	if (port_id >= ssi->num_ports) {
1132 		dev_err(&pd->dev, "port id out of range!\n");
1133 		err = -ENODEV;
1134 		goto error;
1135 	}
1136 
1137 	port = ssi->port[port_id];
1138 
1139 	if (!np) {
1140 		dev_err(&pd->dev, "missing device tree data\n");
1141 		err = -EINVAL;
1142 		goto error;
1143 	}
1144 
1145 	cawake_gpio = devm_gpiod_get(&pd->dev, "ti,ssi-cawake", GPIOD_IN);
1146 	if (IS_ERR(cawake_gpio)) {
1147 		err = PTR_ERR(cawake_gpio);
1148 		dev_err(&pd->dev, "couldn't get cawake gpio (err=%d)!\n", err);
1149 		goto error;
1150 	}
1151 
1152 	omap_port = devm_kzalloc(&port->device, sizeof(*omap_port), GFP_KERNEL);
1153 	if (!omap_port) {
1154 		err = -ENOMEM;
1155 		goto error;
1156 	}
1157 	omap_port->wake_gpio = cawake_gpio;
1158 	omap_port->pdev = &pd->dev;
1159 	omap_port->port_id = port_id;
1160 
1161 	INIT_DEFERRABLE_WORK(&omap_port->errqueue_work, ssi_process_errqueue);
1162 	INIT_WORK(&omap_port->work, start_tx_work);
1163 
1164 	/* initialize HSI port */
1165 	port->async	= ssi_async;
1166 	port->setup	= ssi_setup;
1167 	port->flush	= ssi_flush;
1168 	port->start_tx	= ssi_start_tx;
1169 	port->stop_tx	= ssi_stop_tx;
1170 	port->release	= ssi_release;
1171 	hsi_port_set_drvdata(port, omap_port);
1172 	omap_ssi->port[port_id] = omap_port;
1173 
1174 	platform_set_drvdata(pd, port);
1175 
1176 	err = ssi_port_get_iomem(pd, "tx", &omap_port->sst_base,
1177 		&omap_port->sst_dma);
1178 	if (err < 0)
1179 		goto error;
1180 	err = ssi_port_get_iomem(pd, "rx", &omap_port->ssr_base,
1181 		&omap_port->ssr_dma);
1182 	if (err < 0)
1183 		goto error;
1184 
1185 	err = ssi_port_irq(port, pd);
1186 	if (err < 0)
1187 		goto error;
1188 	err = ssi_wake_irq(port, pd);
1189 	if (err < 0)
1190 		goto error;
1191 
1192 	ssi_queues_init(omap_port);
1193 	spin_lock_init(&omap_port->lock);
1194 	spin_lock_init(&omap_port->wk_lock);
1195 	omap_port->dev = &port->device;
1196 
1197 	pm_runtime_use_autosuspend(omap_port->pdev);
1198 	pm_runtime_set_autosuspend_delay(omap_port->pdev, 250);
1199 	pm_runtime_enable(omap_port->pdev);
1200 
1201 #ifdef CONFIG_DEBUG_FS
1202 	ssi_debug_add_port(omap_port, omap_ssi->dir);
1203 #endif
1204 
1205 	hsi_add_clients_from_dt(port, np);
1206 
1207 	dev_info(&pd->dev, "ssi port %u successfully initialized\n", port_id);
1208 
1209 	return 0;
1210 
1211 error:
1212 	return err;
1213 }
1214 
1215 static void ssi_port_remove(struct platform_device *pd)
1216 {
1217 	struct hsi_port *port = platform_get_drvdata(pd);
1218 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1219 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1220 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1221 
1222 #ifdef CONFIG_DEBUG_FS
1223 	ssi_debug_remove_port(port);
1224 #endif
1225 
1226 	cancel_delayed_work_sync(&omap_port->errqueue_work);
1227 
1228 	hsi_port_unregister_clients(port);
1229 
1230 	port->async	= hsi_dummy_msg;
1231 	port->setup	= hsi_dummy_cl;
1232 	port->flush	= hsi_dummy_cl;
1233 	port->start_tx	= hsi_dummy_cl;
1234 	port->stop_tx	= hsi_dummy_cl;
1235 	port->release	= hsi_dummy_cl;
1236 
1237 	omap_ssi->port[omap_port->port_id] = NULL;
1238 	platform_set_drvdata(pd, NULL);
1239 
1240 	pm_runtime_dont_use_autosuspend(&pd->dev);
1241 	pm_runtime_disable(&pd->dev);
1242 }
1243 
1244 static int ssi_restore_divisor(struct omap_ssi_port *omap_port)
1245 {
1246 	writel_relaxed(omap_port->sst.divisor,
1247 				omap_port->sst_base + SSI_SST_DIVISOR_REG);
1248 
1249 	return 0;
1250 }
1251 
1252 void omap_ssi_port_update_fclk(struct hsi_controller *ssi,
1253 			       struct omap_ssi_port *omap_port)
1254 {
1255 	/* update divisor */
1256 	u32 div = ssi_calculate_div(ssi);
1257 	omap_port->sst.divisor = div;
1258 	ssi_restore_divisor(omap_port);
1259 }
1260 
1261 #ifdef CONFIG_PM
1262 static int ssi_save_port_ctx(struct omap_ssi_port *omap_port)
1263 {
1264 	struct hsi_port *port = to_hsi_port(omap_port->dev);
1265 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1266 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1267 
1268 	omap_port->sys_mpu_enable = readl(omap_ssi->sys +
1269 					SSI_MPU_ENABLE_REG(port->num, 0));
1270 
1271 	return 0;
1272 }
1273 
1274 static int ssi_restore_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 	void __iomem	*base;
1280 
1281 	writel_relaxed(omap_port->sys_mpu_enable,
1282 			omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
1283 
1284 	/* SST context */
1285 	base = omap_port->sst_base;
1286 	writel_relaxed(omap_port->sst.frame_size, base + SSI_SST_FRAMESIZE_REG);
1287 	writel_relaxed(omap_port->sst.channels, base + SSI_SST_CHANNELS_REG);
1288 	writel_relaxed(omap_port->sst.arb_mode, base + SSI_SST_ARBMODE_REG);
1289 
1290 	/* SSR context */
1291 	base = omap_port->ssr_base;
1292 	writel_relaxed(omap_port->ssr.frame_size, base + SSI_SSR_FRAMESIZE_REG);
1293 	writel_relaxed(omap_port->ssr.channels, base + SSI_SSR_CHANNELS_REG);
1294 	writel_relaxed(omap_port->ssr.timeout, base + SSI_SSR_TIMEOUT_REG);
1295 
1296 	return 0;
1297 }
1298 
1299 static int ssi_restore_port_mode(struct omap_ssi_port *omap_port)
1300 {
1301 	writel_relaxed(omap_port->sst.mode,
1302 				omap_port->sst_base + SSI_SST_MODE_REG);
1303 	writel_relaxed(omap_port->ssr.mode,
1304 				omap_port->ssr_base + SSI_SSR_MODE_REG);
1305 	/* OCP barrier */
1306 	readl(omap_port->ssr_base + SSI_SSR_MODE_REG);
1307 
1308 	return 0;
1309 }
1310 
1311 static int omap_ssi_port_runtime_suspend(struct device *dev)
1312 {
1313 	struct hsi_port *port = dev_get_drvdata(dev);
1314 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1315 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1316 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1317 
1318 	dev_dbg(dev, "port runtime suspend!\n");
1319 
1320 	ssi_set_port_mode(omap_port, SSI_MODE_SLEEP);
1321 	if (omap_ssi->get_loss)
1322 		omap_port->loss_count =
1323 				omap_ssi->get_loss(ssi->device.parent);
1324 	ssi_save_port_ctx(omap_port);
1325 
1326 	return 0;
1327 }
1328 
1329 static int omap_ssi_port_runtime_resume(struct device *dev)
1330 {
1331 	struct hsi_port *port = dev_get_drvdata(dev);
1332 	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
1333 	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
1334 	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
1335 
1336 	dev_dbg(dev, "port runtime resume!\n");
1337 
1338 	if ((omap_ssi->get_loss) && (omap_port->loss_count ==
1339 				omap_ssi->get_loss(ssi->device.parent)))
1340 		goto mode; /* We always need to restore the mode & TX divisor */
1341 
1342 	ssi_restore_port_ctx(omap_port);
1343 
1344 mode:
1345 	ssi_restore_divisor(omap_port);
1346 	ssi_restore_port_mode(omap_port);
1347 
1348 	return 0;
1349 }
1350 
1351 static const struct dev_pm_ops omap_ssi_port_pm_ops = {
1352 	SET_RUNTIME_PM_OPS(omap_ssi_port_runtime_suspend,
1353 		omap_ssi_port_runtime_resume, NULL)
1354 };
1355 
1356 #define DEV_PM_OPS     (&omap_ssi_port_pm_ops)
1357 #else
1358 #define DEV_PM_OPS     NULL
1359 #endif
1360 
1361 
1362 #ifdef CONFIG_OF
1363 static const struct of_device_id omap_ssi_port_of_match[] = {
1364 	{ .compatible = "ti,omap3-ssi-port", },
1365 	{},
1366 };
1367 MODULE_DEVICE_TABLE(of, omap_ssi_port_of_match);
1368 #else
1369 #define omap_ssi_port_of_match NULL
1370 #endif
1371 
1372 struct platform_driver ssi_port_pdriver = {
1373 	.probe = ssi_port_probe,
1374 	.remove = ssi_port_remove,
1375 	.driver	= {
1376 		.name	= "omap_ssi_port",
1377 		.of_match_table = omap_ssi_port_of_match,
1378 		.pm	= DEV_PM_OPS,
1379 	},
1380 };
1381