xref: /linux/drivers/gpu/drm/imx/dcss/dcss-ctxld.c (revision 6d9b262afe0ec1d6e0ef99321ca9d6b921310471)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2019 NXP.
4  */
5 
6 #include <linux/delay.h>
7 #include <linux/dma-mapping.h>
8 #include <linux/interrupt.h>
9 #include <linux/platform_device.h>
10 #include <linux/slab.h>
11 
12 #include "dcss-dev.h"
13 
14 #define DCSS_CTXLD_CONTROL_STATUS	0x0
15 #define   CTXLD_ENABLE			BIT(0)
16 #define   ARB_SEL			BIT(1)
17 #define   RD_ERR_EN			BIT(2)
18 #define   DB_COMP_EN			BIT(3)
19 #define   SB_HP_COMP_EN			BIT(4)
20 #define   SB_LP_COMP_EN			BIT(5)
21 #define   DB_PEND_SB_REC_EN		BIT(6)
22 #define   SB_PEND_DISP_ACTIVE_EN	BIT(7)
23 #define   AHB_ERR_EN			BIT(8)
24 #define   RD_ERR			BIT(16)
25 #define   DB_COMP			BIT(17)
26 #define   SB_HP_COMP			BIT(18)
27 #define   SB_LP_COMP			BIT(19)
28 #define   DB_PEND_SB_REC		BIT(20)
29 #define   SB_PEND_DISP_ACTIVE		BIT(21)
30 #define   AHB_ERR			BIT(22)
31 #define DCSS_CTXLD_DB_BASE_ADDR		0x10
32 #define DCSS_CTXLD_DB_COUNT		0x14
33 #define DCSS_CTXLD_SB_BASE_ADDR		0x18
34 #define DCSS_CTXLD_SB_COUNT		0x1C
35 #define   SB_HP_COUNT_POS		0
36 #define   SB_HP_COUNT_MASK		0xffff
37 #define   SB_LP_COUNT_POS		16
38 #define   SB_LP_COUNT_MASK		0xffff0000
39 #define DCSS_AHB_ERR_ADDR		0x20
40 
41 #define CTXLD_IRQ_COMPLETION		(DB_COMP | SB_HP_COMP | SB_LP_COMP)
42 #define CTXLD_IRQ_ERROR			(RD_ERR | DB_PEND_SB_REC | AHB_ERR)
43 
44 /* The following sizes are in context loader entries, 8 bytes each. */
45 #define CTXLD_DB_CTX_ENTRIES		1024	/* max 65536 */
46 #define CTXLD_SB_LP_CTX_ENTRIES		10240	/* max 65536 */
47 #define CTXLD_SB_HP_CTX_ENTRIES		20000	/* max 65536 */
48 #define CTXLD_SB_CTX_ENTRIES		(CTXLD_SB_LP_CTX_ENTRIES + \
49 					 CTXLD_SB_HP_CTX_ENTRIES)
50 
51 /* Sizes, in entries, of the DB, SB_HP and SB_LP context regions. */
52 static u16 dcss_ctxld_ctx_size[3] = {
53 	CTXLD_DB_CTX_ENTRIES,
54 	CTXLD_SB_HP_CTX_ENTRIES,
55 	CTXLD_SB_LP_CTX_ENTRIES
56 };
57 
58 /* this represents an entry in the context loader map */
59 struct dcss_ctxld_item {
60 	u32 val;
61 	u32 ofs;
62 };
63 
64 #define CTX_ITEM_SIZE			sizeof(struct dcss_ctxld_item)
65 
66 struct dcss_ctxld {
67 	struct device *dev;
68 	void __iomem *ctxld_reg;
69 	int irq;
70 	bool irq_en;
71 
72 	struct dcss_ctxld_item *db[2];
73 	struct dcss_ctxld_item *sb_hp[2];
74 	struct dcss_ctxld_item *sb_lp[2];
75 
76 	dma_addr_t db_paddr[2];
77 	dma_addr_t sb_paddr[2];
78 
79 	u16 ctx_size[2][3]; /* holds the sizes of DB, SB_HP and SB_LP ctx */
80 	u8 current_ctx;
81 
82 	bool in_use;
83 	bool armed;
84 
85 	spinlock_t lock; /* protects concurent access to private data */
86 };
87 
88 static irqreturn_t dcss_ctxld_irq_handler(int irq, void *data)
89 {
90 	struct dcss_ctxld *ctxld = data;
91 	struct dcss_dev *dcss = dcss_drv_dev_to_dcss(ctxld->dev);
92 	u32 irq_status;
93 
94 	irq_status = dcss_readl(ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);
95 
96 	if (irq_status & CTXLD_IRQ_COMPLETION &&
97 	    !(irq_status & CTXLD_ENABLE) && ctxld->in_use) {
98 		ctxld->in_use = false;
99 
100 		if (dcss && dcss->disable_callback)
101 			dcss->disable_callback(dcss);
102 	} else if (irq_status & CTXLD_IRQ_ERROR) {
103 		/*
104 		 * Except for throwing an error message and clearing the status
105 		 * register, there's not much we can do here.
106 		 */
107 		dev_err(ctxld->dev, "ctxld: error encountered: %08x\n",
108 			irq_status);
109 		dev_err(ctxld->dev, "ctxld: db=%d, sb_hp=%d, sb_lp=%d\n",
110 			ctxld->ctx_size[ctxld->current_ctx ^ 1][CTX_DB],
111 			ctxld->ctx_size[ctxld->current_ctx ^ 1][CTX_SB_HP],
112 			ctxld->ctx_size[ctxld->current_ctx ^ 1][CTX_SB_LP]);
113 	}
114 
115 	dcss_clr(irq_status & (CTXLD_IRQ_ERROR | CTXLD_IRQ_COMPLETION),
116 		 ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);
117 
118 	return IRQ_HANDLED;
119 }
120 
121 static int dcss_ctxld_irq_config(struct dcss_ctxld *ctxld,
122 				 struct platform_device *pdev)
123 {
124 	int ret;
125 
126 	ctxld->irq = platform_get_irq_byname(pdev, "ctxld");
127 	if (ctxld->irq < 0)
128 		return ctxld->irq;
129 
130 	ret = request_irq(ctxld->irq, dcss_ctxld_irq_handler,
131 			  0, "dcss_ctxld", ctxld);
132 	if (ret) {
133 		dev_err(ctxld->dev, "ctxld: irq request failed.\n");
134 		return ret;
135 	}
136 
137 	ctxld->irq_en = true;
138 
139 	return 0;
140 }
141 
142 static void dcss_ctxld_hw_cfg(struct dcss_ctxld *ctxld)
143 {
144 	dcss_writel(RD_ERR_EN | SB_HP_COMP_EN |
145 		    DB_PEND_SB_REC_EN | AHB_ERR_EN | RD_ERR | AHB_ERR,
146 		    ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);
147 }
148 
149 static void dcss_ctxld_free_ctx(struct dcss_ctxld *ctxld)
150 {
151 	struct dcss_ctxld_item *ctx;
152 	int i;
153 
154 	for (i = 0; i < 2; i++) {
155 		if (ctxld->db[i]) {
156 			dma_free_coherent(ctxld->dev,
157 					  CTXLD_DB_CTX_ENTRIES * sizeof(*ctx),
158 					  ctxld->db[i], ctxld->db_paddr[i]);
159 			ctxld->db[i] = NULL;
160 			ctxld->db_paddr[i] = 0;
161 		}
162 
163 		if (ctxld->sb_hp[i]) {
164 			dma_free_coherent(ctxld->dev,
165 					  CTXLD_SB_CTX_ENTRIES * sizeof(*ctx),
166 					  ctxld->sb_hp[i], ctxld->sb_paddr[i]);
167 			ctxld->sb_hp[i] = NULL;
168 			ctxld->sb_paddr[i] = 0;
169 		}
170 	}
171 }
172 
173 static int dcss_ctxld_alloc_ctx(struct dcss_ctxld *ctxld)
174 {
175 	struct dcss_ctxld_item *ctx;
176 	int i;
177 
178 	for (i = 0; i < 2; i++) {
179 		ctx = dma_alloc_coherent(ctxld->dev,
180 					 CTXLD_DB_CTX_ENTRIES * sizeof(*ctx),
181 					 &ctxld->db_paddr[i], GFP_KERNEL);
182 		if (!ctx)
183 			return -ENOMEM;
184 
185 		ctxld->db[i] = ctx;
186 
187 		ctx = dma_alloc_coherent(ctxld->dev,
188 					 CTXLD_SB_CTX_ENTRIES * sizeof(*ctx),
189 					 &ctxld->sb_paddr[i], GFP_KERNEL);
190 		if (!ctx)
191 			return -ENOMEM;
192 
193 		ctxld->sb_hp[i] = ctx;
194 		ctxld->sb_lp[i] = ctx + CTXLD_SB_HP_CTX_ENTRIES;
195 	}
196 
197 	return 0;
198 }
199 
200 int dcss_ctxld_init(struct dcss_dev *dcss, unsigned long ctxld_base)
201 {
202 	struct dcss_ctxld *ctxld;
203 	int ret;
204 
205 	ctxld = devm_kzalloc(dcss->dev, sizeof(*ctxld), GFP_KERNEL);
206 	if (!ctxld)
207 		return -ENOMEM;
208 
209 	dcss->ctxld = ctxld;
210 	ctxld->dev = dcss->dev;
211 
212 	spin_lock_init(&ctxld->lock);
213 
214 	ret = dcss_ctxld_alloc_ctx(ctxld);
215 	if (ret) {
216 		dev_err(dcss->dev, "ctxld: cannot allocate context memory.\n");
217 		goto err;
218 	}
219 
220 	ctxld->ctxld_reg = devm_ioremap(dcss->dev, ctxld_base, SZ_4K);
221 	if (!ctxld->ctxld_reg) {
222 		dev_err(dcss->dev, "ctxld: unable to remap ctxld base\n");
223 		ret = -ENOMEM;
224 		goto err;
225 	}
226 
227 	ret = dcss_ctxld_irq_config(ctxld, to_platform_device(dcss->dev));
228 	if (ret)
229 		goto err;
230 
231 	dcss_ctxld_hw_cfg(ctxld);
232 
233 	return 0;
234 
235 err:
236 	dcss_ctxld_free_ctx(ctxld);
237 
238 	return ret;
239 }
240 
241 void dcss_ctxld_exit(struct dcss_ctxld *ctxld)
242 {
243 	free_irq(ctxld->irq, ctxld);
244 
245 	dcss_ctxld_free_ctx(ctxld);
246 }
247 
248 static int dcss_ctxld_enable_locked(struct dcss_ctxld *ctxld)
249 {
250 	int curr_ctx = ctxld->current_ctx;
251 	u32 db_base, sb_base, sb_count;
252 	u32 sb_hp_cnt, sb_lp_cnt, db_cnt;
253 	struct dcss_dev *dcss = dcss_drv_dev_to_dcss(ctxld->dev);
254 
255 	if (!dcss)
256 		return 0;
257 
258 	dcss_dpr_write_sysctrl(dcss->dpr);
259 
260 	dcss_scaler_write_sclctrl(dcss->scaler);
261 
262 	sb_hp_cnt = ctxld->ctx_size[curr_ctx][CTX_SB_HP];
263 	sb_lp_cnt = ctxld->ctx_size[curr_ctx][CTX_SB_LP];
264 	db_cnt = ctxld->ctx_size[curr_ctx][CTX_DB];
265 
266 	/* make sure SB_LP context area comes after SB_HP */
267 	if (sb_lp_cnt &&
268 	    ctxld->sb_lp[curr_ctx] != ctxld->sb_hp[curr_ctx] + sb_hp_cnt) {
269 		struct dcss_ctxld_item *sb_lp_adjusted;
270 
271 		sb_lp_adjusted = ctxld->sb_hp[curr_ctx] + sb_hp_cnt;
272 
273 		memcpy(sb_lp_adjusted, ctxld->sb_lp[curr_ctx],
274 		       sb_lp_cnt * CTX_ITEM_SIZE);
275 	}
276 
277 	db_base = db_cnt ? ctxld->db_paddr[curr_ctx] : 0;
278 
279 	dcss_writel(db_base, ctxld->ctxld_reg + DCSS_CTXLD_DB_BASE_ADDR);
280 	dcss_writel(db_cnt, ctxld->ctxld_reg + DCSS_CTXLD_DB_COUNT);
281 
282 	if (sb_hp_cnt)
283 		sb_count = ((sb_hp_cnt << SB_HP_COUNT_POS) & SB_HP_COUNT_MASK) |
284 			   ((sb_lp_cnt << SB_LP_COUNT_POS) & SB_LP_COUNT_MASK);
285 	else
286 		sb_count = (sb_lp_cnt << SB_HP_COUNT_POS) & SB_HP_COUNT_MASK;
287 
288 	sb_base = sb_count ? ctxld->sb_paddr[curr_ctx] : 0;
289 
290 	dcss_writel(sb_base, ctxld->ctxld_reg + DCSS_CTXLD_SB_BASE_ADDR);
291 	dcss_writel(sb_count, ctxld->ctxld_reg + DCSS_CTXLD_SB_COUNT);
292 
293 	/* enable the context loader */
294 	dcss_set(CTXLD_ENABLE, ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);
295 
296 	ctxld->in_use = true;
297 
298 	/*
299 	 * Toggle the current context to the alternate one so that any updates
300 	 * in the modules' settings take place there.
301 	 */
302 	ctxld->current_ctx ^= 1;
303 
304 	ctxld->ctx_size[ctxld->current_ctx][CTX_DB] = 0;
305 	ctxld->ctx_size[ctxld->current_ctx][CTX_SB_HP] = 0;
306 	ctxld->ctx_size[ctxld->current_ctx][CTX_SB_LP] = 0;
307 
308 	return 0;
309 }
310 
311 int dcss_ctxld_enable(struct dcss_ctxld *ctxld)
312 {
313 	spin_lock_irq(&ctxld->lock);
314 	ctxld->armed = true;
315 	spin_unlock_irq(&ctxld->lock);
316 
317 	return 0;
318 }
319 
320 void dcss_ctxld_kick(struct dcss_ctxld *ctxld)
321 {
322 	unsigned long flags;
323 
324 	spin_lock_irqsave(&ctxld->lock, flags);
325 	if (ctxld->armed && !ctxld->in_use) {
326 		ctxld->armed = false;
327 		dcss_ctxld_enable_locked(ctxld);
328 	}
329 	spin_unlock_irqrestore(&ctxld->lock, flags);
330 }
331 
332 void dcss_ctxld_write_irqsafe(struct dcss_ctxld *ctxld, u32 ctx_id, u32 val,
333 			      u32 reg_ofs)
334 {
335 	int curr_ctx = ctxld->current_ctx;
336 	struct dcss_ctxld_item *ctx[] = {
337 		[CTX_DB] = ctxld->db[curr_ctx],
338 		[CTX_SB_HP] = ctxld->sb_hp[curr_ctx],
339 		[CTX_SB_LP] = ctxld->sb_lp[curr_ctx]
340 	};
341 	int item_idx = ctxld->ctx_size[curr_ctx][ctx_id];
342 
343 	if (item_idx + 1 > dcss_ctxld_ctx_size[ctx_id]) {
344 		WARN_ON(1);
345 		return;
346 	}
347 
348 	ctx[ctx_id][item_idx].val = val;
349 	ctx[ctx_id][item_idx].ofs = reg_ofs;
350 	ctxld->ctx_size[curr_ctx][ctx_id] += 1;
351 }
352 
353 void dcss_ctxld_write(struct dcss_ctxld *ctxld, u32 ctx_id,
354 		      u32 val, u32 reg_ofs)
355 {
356 	spin_lock_irq(&ctxld->lock);
357 	dcss_ctxld_write_irqsafe(ctxld, ctx_id, val, reg_ofs);
358 	spin_unlock_irq(&ctxld->lock);
359 }
360 
361 bool dcss_ctxld_is_flushed(struct dcss_ctxld *ctxld)
362 {
363 	return ctxld->ctx_size[ctxld->current_ctx][CTX_DB] == 0 &&
364 		ctxld->ctx_size[ctxld->current_ctx][CTX_SB_HP] == 0 &&
365 		ctxld->ctx_size[ctxld->current_ctx][CTX_SB_LP] == 0;
366 }
367 
368 int dcss_ctxld_resume(struct dcss_ctxld *ctxld)
369 {
370 	dcss_ctxld_hw_cfg(ctxld);
371 
372 	if (!ctxld->irq_en) {
373 		enable_irq(ctxld->irq);
374 		ctxld->irq_en = true;
375 	}
376 
377 	return 0;
378 }
379 
380 int dcss_ctxld_suspend(struct dcss_ctxld *ctxld)
381 {
382 	int ret = 0;
383 	unsigned long timeout = jiffies + msecs_to_jiffies(500);
384 
385 	if (!dcss_ctxld_is_flushed(ctxld)) {
386 		dcss_ctxld_kick(ctxld);
387 
388 		while (!time_after(jiffies, timeout) && ctxld->in_use)
389 			msleep(20);
390 
391 		if (time_after(jiffies, timeout))
392 			return -ETIMEDOUT;
393 	}
394 
395 	spin_lock_irq(&ctxld->lock);
396 
397 	if (ctxld->irq_en) {
398 		disable_irq_nosync(ctxld->irq);
399 		ctxld->irq_en = false;
400 	}
401 
402 	/* reset context region and sizes */
403 	ctxld->current_ctx = 0;
404 	ctxld->ctx_size[0][CTX_DB] = 0;
405 	ctxld->ctx_size[0][CTX_SB_HP] = 0;
406 	ctxld->ctx_size[0][CTX_SB_LP] = 0;
407 
408 	spin_unlock_irq(&ctxld->lock);
409 
410 	return ret;
411 }
412 
413 void dcss_ctxld_assert_locked(struct dcss_ctxld *ctxld)
414 {
415 	lockdep_assert_held(&ctxld->lock);
416 }
417