xref: /linux/drivers/char/ipmi/kcs_bmc_aspeed.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2015-2018, Intel Corporation.
4  */
5 
6 #define pr_fmt(fmt) "aspeed-kcs-bmc: " fmt
7 
8 #include <linux/atomic.h>
9 #include <linux/errno.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/irq.h>
13 #include <linux/mfd/syscon.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/platform_device.h>
18 #include <linux/poll.h>
19 #include <linux/regmap.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/timer.h>
23 
24 #include "kcs_bmc_device.h"
25 
26 
27 #define DEVICE_NAME     "ast-kcs-bmc"
28 
29 #define KCS_CHANNEL_MAX     4
30 
31 /*
32  * Field class descriptions
33  *
34  * LPCyE	Enable LPC channel y
35  * IBFIEy	Input Buffer Full IRQ Enable for LPC channel y
36  * IRQxEy	Assert SerIRQ x for LPC channel y (Deprecated, use IDyIRQX, IRQXEy)
37  * IDyIRQX	Use the specified 4-bit SerIRQ for LPC channel y
38  * SELyIRQX	SerIRQ polarity for LPC channel y (low: 0, high: 1)
39  * IRQXEy	Assert the SerIRQ specified in IDyIRQX for LPC channel y
40  */
41 
42 #define LPC_TYIRQX_LOW       0b00
43 #define LPC_TYIRQX_HIGH      0b01
44 #define LPC_TYIRQX_RSVD      0b10
45 #define LPC_TYIRQX_RISING    0b11
46 
47 #define LPC_HICR0            0x000
48 #define     LPC_HICR0_LPC3E          BIT(7)
49 #define     LPC_HICR0_LPC2E          BIT(6)
50 #define     LPC_HICR0_LPC1E          BIT(5)
51 #define LPC_HICR2            0x008
52 #define     LPC_HICR2_IBFIE3         BIT(3)
53 #define     LPC_HICR2_IBFIE2         BIT(2)
54 #define     LPC_HICR2_IBFIE1         BIT(1)
55 #define LPC_HICR4            0x010
56 #define     LPC_HICR4_LADR12AS       BIT(7)
57 #define     LPC_HICR4_KCSENBL        BIT(2)
58 #define LPC_SIRQCR0	     0x070
59 /* IRQ{12,1}E1 are deprecated as of AST2600 A3 but necessary for prior chips */
60 #define     LPC_SIRQCR0_IRQ12E1	     BIT(1)
61 #define     LPC_SIRQCR0_IRQ1E1	     BIT(0)
62 #define LPC_HICR5	     0x080
63 #define     LPC_HICR5_ID3IRQX_MASK   GENMASK(23, 20)
64 #define     LPC_HICR5_ID3IRQX_SHIFT  20
65 #define     LPC_HICR5_ID2IRQX_MASK   GENMASK(19, 16)
66 #define     LPC_HICR5_ID2IRQX_SHIFT  16
67 #define     LPC_HICR5_SEL3IRQX       BIT(15)
68 #define     LPC_HICR5_IRQXE3         BIT(14)
69 #define     LPC_HICR5_SEL2IRQX       BIT(13)
70 #define     LPC_HICR5_IRQXE2         BIT(12)
71 #define LPC_LADR3H           0x014
72 #define LPC_LADR3L           0x018
73 #define LPC_LADR12H          0x01C
74 #define LPC_LADR12L          0x020
75 #define LPC_IDR1             0x024
76 #define LPC_IDR2             0x028
77 #define LPC_IDR3             0x02C
78 #define LPC_ODR1             0x030
79 #define LPC_ODR2             0x034
80 #define LPC_ODR3             0x038
81 #define LPC_STR1             0x03C
82 #define LPC_STR2             0x040
83 #define LPC_STR3             0x044
84 #define LPC_HICRB            0x100
85 #define     LPC_HICRB_EN16LADR2      BIT(5)
86 #define     LPC_HICRB_EN16LADR1      BIT(4)
87 #define     LPC_HICRB_IBFIE4         BIT(1)
88 #define     LPC_HICRB_LPC4E          BIT(0)
89 #define LPC_HICRC            0x104
90 #define     LPC_HICRC_ID4IRQX_MASK   GENMASK(7, 4)
91 #define     LPC_HICRC_ID4IRQX_SHIFT  4
92 #define     LPC_HICRC_TY4IRQX_MASK   GENMASK(3, 2)
93 #define     LPC_HICRC_TY4IRQX_SHIFT  2
94 #define     LPC_HICRC_OBF4_AUTO_CLR  BIT(1)
95 #define     LPC_HICRC_IRQXE4         BIT(0)
96 #define LPC_LADR4            0x110
97 #define LPC_IDR4             0x114
98 #define LPC_ODR4             0x118
99 #define LPC_STR4             0x11C
100 #define LPC_LSADR12	     0x120
101 #define     LPC_LSADR12_LSADR2_MASK  GENMASK(31, 16)
102 #define     LPC_LSADR12_LSADR2_SHIFT 16
103 #define     LPC_LSADR12_LSADR1_MASK  GENMASK(15, 0)
104 #define     LPC_LSADR12_LSADR1_SHIFT 0
105 
106 #define OBE_POLL_PERIOD	     (HZ / 2)
107 
108 enum aspeed_kcs_irq_mode {
109 	aspeed_kcs_irq_none,
110 	aspeed_kcs_irq_serirq,
111 };
112 
113 struct aspeed_kcs_bmc {
114 	struct kcs_bmc_device kcs_bmc;
115 
116 	struct regmap *map;
117 
118 	struct {
119 		enum aspeed_kcs_irq_mode mode;
120 		int id;
121 	} upstream_irq;
122 
123 	struct {
124 		spinlock_t lock;
125 		bool remove;
126 		struct timer_list timer;
127 	} obe;
128 };
129 
130 static inline struct aspeed_kcs_bmc *to_aspeed_kcs_bmc(struct kcs_bmc_device *kcs_bmc)
131 {
132 	return container_of(kcs_bmc, struct aspeed_kcs_bmc, kcs_bmc);
133 }
134 
135 static u8 aspeed_kcs_inb(struct kcs_bmc_device *kcs_bmc, u32 reg)
136 {
137 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
138 	u32 val = 0;
139 	int rc;
140 
141 	rc = regmap_read(priv->map, reg, &val);
142 	WARN(rc != 0, "regmap_read() failed: %d\n", rc);
143 
144 	return rc == 0 ? (u8) val : 0;
145 }
146 
147 static void aspeed_kcs_outb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 data)
148 {
149 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
150 	int rc;
151 
152 	rc = regmap_write(priv->map, reg, data);
153 	WARN(rc != 0, "regmap_write() failed: %d\n", rc);
154 
155 	/* Trigger the upstream IRQ on ODR writes, if enabled */
156 
157 	switch (reg) {
158 	case LPC_ODR1:
159 	case LPC_ODR2:
160 	case LPC_ODR3:
161 	case LPC_ODR4:
162 		break;
163 	default:
164 		return;
165 	}
166 
167 	if (priv->upstream_irq.mode != aspeed_kcs_irq_serirq)
168 		return;
169 
170 	switch (kcs_bmc->channel) {
171 	case 1:
172 		switch (priv->upstream_irq.id) {
173 		case 12:
174 			regmap_update_bits(priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ12E1,
175 					   LPC_SIRQCR0_IRQ12E1);
176 			break;
177 		case 1:
178 			regmap_update_bits(priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ1E1,
179 					   LPC_SIRQCR0_IRQ1E1);
180 			break;
181 		default:
182 			break;
183 		}
184 		break;
185 	case 2:
186 		regmap_update_bits(priv->map, LPC_HICR5, LPC_HICR5_IRQXE2, LPC_HICR5_IRQXE2);
187 		break;
188 	case 3:
189 		regmap_update_bits(priv->map, LPC_HICR5, LPC_HICR5_IRQXE3, LPC_HICR5_IRQXE3);
190 		break;
191 	case 4:
192 		regmap_update_bits(priv->map, LPC_HICRC, LPC_HICRC_IRQXE4, LPC_HICRC_IRQXE4);
193 		break;
194 	default:
195 		break;
196 	}
197 }
198 
199 static void aspeed_kcs_updateb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 val)
200 {
201 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
202 	int rc;
203 
204 	rc = regmap_update_bits(priv->map, reg, mask, val);
205 	WARN(rc != 0, "regmap_update_bits() failed: %d\n", rc);
206 }
207 
208 /*
209  * We note D for Data, and C for Cmd/Status, default rules are
210  *
211  * 1. Only the D address is given:
212  *   A. KCS1/KCS2 (D/C: X/X+4)
213  *      D/C: CA0h/CA4h
214  *      D/C: CA8h/CACh
215  *   B. KCS3 (D/C: XX2/XX3h)
216  *      D/C: CA2h/CA3h
217  *   C. KCS4 (D/C: X/X+1)
218  *      D/C: CA4h/CA5h
219  *
220  * 2. Both the D/C addresses are given:
221  *   A. KCS1/KCS2/KCS4 (D/C: X/Y)
222  *      D/C: CA0h/CA1h
223  *      D/C: CA8h/CA9h
224  *      D/C: CA4h/CA5h
225  *   B. KCS3 (D/C: XX2/XX3h)
226  *      D/C: CA2h/CA3h
227  */
228 static int aspeed_kcs_set_address(struct kcs_bmc_device *kcs_bmc, u32 addrs[2], int nr_addrs)
229 {
230 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
231 
232 	if (WARN_ON(nr_addrs < 1 || nr_addrs > 2))
233 		return -EINVAL;
234 
235 	switch (priv->kcs_bmc.channel) {
236 	case 1:
237 		regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, 0);
238 		regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8);
239 		regmap_write(priv->map, LPC_LADR12L, addrs[0] & 0xFF);
240 		if (nr_addrs == 2) {
241 			regmap_update_bits(priv->map, LPC_LSADR12, LPC_LSADR12_LSADR1_MASK,
242 					   addrs[1] << LPC_LSADR12_LSADR1_SHIFT);
243 
244 			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_EN16LADR1,
245 					   LPC_HICRB_EN16LADR1);
246 		}
247 		break;
248 
249 	case 2:
250 		regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, LPC_HICR4_LADR12AS);
251 		regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8);
252 		regmap_write(priv->map, LPC_LADR12L, addrs[0] & 0xFF);
253 		if (nr_addrs == 2) {
254 			regmap_update_bits(priv->map, LPC_LSADR12, LPC_LSADR12_LSADR2_MASK,
255 					   addrs[1] << LPC_LSADR12_LSADR2_SHIFT);
256 
257 			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_EN16LADR2,
258 					   LPC_HICRB_EN16LADR2);
259 		}
260 		break;
261 
262 	case 3:
263 		if (nr_addrs == 2) {
264 			dev_err(priv->kcs_bmc.dev,
265 				"Channel 3 only supports inferred status IO address\n");
266 			return -EINVAL;
267 		}
268 
269 		regmap_write(priv->map, LPC_LADR3H, addrs[0] >> 8);
270 		regmap_write(priv->map, LPC_LADR3L, addrs[0] & 0xFF);
271 		break;
272 
273 	case 4:
274 		if (nr_addrs == 1)
275 			regmap_write(priv->map, LPC_LADR4, ((addrs[0] + 1) << 16) | addrs[0]);
276 		else
277 			regmap_write(priv->map, LPC_LADR4, (addrs[1] << 16) | addrs[0]);
278 
279 		break;
280 
281 	default:
282 		return -EINVAL;
283 	}
284 
285 	return 0;
286 }
287 
288 static inline int aspeed_kcs_map_serirq_type(u32 dt_type)
289 {
290 	switch (dt_type) {
291 	case IRQ_TYPE_EDGE_RISING:
292 		return LPC_TYIRQX_RISING;
293 	case IRQ_TYPE_LEVEL_HIGH:
294 		return LPC_TYIRQX_HIGH;
295 	case IRQ_TYPE_LEVEL_LOW:
296 		return LPC_TYIRQX_LOW;
297 	default:
298 		return -EINVAL;
299 	}
300 }
301 
302 static int aspeed_kcs_config_upstream_irq(struct aspeed_kcs_bmc *priv, u32 id, u32 dt_type)
303 {
304 	unsigned int mask, val, hw_type;
305 	int ret;
306 
307 	if (id > 15)
308 		return -EINVAL;
309 
310 	ret = aspeed_kcs_map_serirq_type(dt_type);
311 	if (ret < 0)
312 		return ret;
313 	hw_type = ret;
314 
315 	priv->upstream_irq.mode = aspeed_kcs_irq_serirq;
316 	priv->upstream_irq.id = id;
317 
318 	switch (priv->kcs_bmc.channel) {
319 	case 1:
320 		/* Needs IRQxE1 rather than (ID1IRQX, SEL1IRQX, IRQXE1) before AST2600 A3 */
321 		break;
322 	case 2:
323 		if (!(hw_type == LPC_TYIRQX_LOW || hw_type == LPC_TYIRQX_HIGH))
324 			return -EINVAL;
325 
326 		mask = LPC_HICR5_SEL2IRQX | LPC_HICR5_ID2IRQX_MASK;
327 		val = (id << LPC_HICR5_ID2IRQX_SHIFT);
328 		val |= (hw_type == LPC_TYIRQX_HIGH) ? LPC_HICR5_SEL2IRQX : 0;
329 		regmap_update_bits(priv->map, LPC_HICR5, mask, val);
330 
331 		break;
332 	case 3:
333 		if (!(hw_type == LPC_TYIRQX_LOW || hw_type == LPC_TYIRQX_HIGH))
334 			return -EINVAL;
335 
336 		mask = LPC_HICR5_SEL3IRQX | LPC_HICR5_ID3IRQX_MASK;
337 		val = (id << LPC_HICR5_ID3IRQX_SHIFT);
338 		val |= (hw_type == LPC_TYIRQX_HIGH) ? LPC_HICR5_SEL3IRQX : 0;
339 		regmap_update_bits(priv->map, LPC_HICR5, mask, val);
340 
341 		break;
342 	case 4:
343 		mask = LPC_HICRC_ID4IRQX_MASK | LPC_HICRC_TY4IRQX_MASK | LPC_HICRC_OBF4_AUTO_CLR;
344 		val = (id << LPC_HICRC_ID4IRQX_SHIFT) | (hw_type << LPC_HICRC_TY4IRQX_SHIFT);
345 		regmap_update_bits(priv->map, LPC_HICRC, mask, val);
346 		break;
347 	default:
348 		dev_warn(priv->kcs_bmc.dev,
349 			 "SerIRQ configuration not supported on KCS channel %d\n",
350 			 priv->kcs_bmc.channel);
351 		return -EINVAL;
352 	}
353 
354 	return 0;
355 }
356 
357 static void aspeed_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enable)
358 {
359 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
360 
361 	switch (kcs_bmc->channel) {
362 	case 1:
363 		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC1E, enable * LPC_HICR0_LPC1E);
364 		return;
365 	case 2:
366 		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC2E, enable * LPC_HICR0_LPC2E);
367 		return;
368 	case 3:
369 		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC3E, enable * LPC_HICR0_LPC3E);
370 		regmap_update_bits(priv->map, LPC_HICR4,
371 				   LPC_HICR4_KCSENBL, enable * LPC_HICR4_KCSENBL);
372 		return;
373 	case 4:
374 		regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_LPC4E, enable * LPC_HICRB_LPC4E);
375 		return;
376 	default:
377 		pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
378 		return;
379 	}
380 }
381 
382 static void aspeed_kcs_check_obe(struct timer_list *timer)
383 {
384 	struct aspeed_kcs_bmc *priv = container_of(timer, struct aspeed_kcs_bmc, obe.timer);
385 	unsigned long flags;
386 	u8 str;
387 
388 	spin_lock_irqsave(&priv->obe.lock, flags);
389 	if (priv->obe.remove) {
390 		spin_unlock_irqrestore(&priv->obe.lock, flags);
391 		return;
392 	}
393 
394 	str = aspeed_kcs_inb(&priv->kcs_bmc, priv->kcs_bmc.ioreg.str);
395 	if (str & KCS_BMC_STR_OBF) {
396 		mod_timer(timer, jiffies + OBE_POLL_PERIOD);
397 		spin_unlock_irqrestore(&priv->obe.lock, flags);
398 		return;
399 	}
400 	spin_unlock_irqrestore(&priv->obe.lock, flags);
401 
402 	kcs_bmc_handle_event(&priv->kcs_bmc);
403 }
404 
405 static void aspeed_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 state)
406 {
407 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
408 	int rc;
409 	u8 str;
410 
411 	/* We don't have an OBE IRQ, emulate it */
412 	if (mask & KCS_BMC_EVENT_TYPE_OBE) {
413 		if (KCS_BMC_EVENT_TYPE_OBE & state) {
414 			/*
415 			 * Given we don't have an OBE IRQ, delay by polling briefly to see if we can
416 			 * observe such an event before returning to the caller. This is not
417 			 * incorrect because OBF may have already become clear before enabling the
418 			 * IRQ if we had one, under which circumstance no event will be propagated
419 			 * anyway.
420 			 *
421 			 * The onus is on the client to perform a race-free check that it hasn't
422 			 * missed the event.
423 			 */
424 			rc = read_poll_timeout_atomic(aspeed_kcs_inb, str,
425 						      !(str & KCS_BMC_STR_OBF), 1, 100, false,
426 						      &priv->kcs_bmc, priv->kcs_bmc.ioreg.str);
427 			/* Time for the slow path? */
428 			if (rc == -ETIMEDOUT)
429 				mod_timer(&priv->obe.timer, jiffies + OBE_POLL_PERIOD);
430 		} else {
431 			del_timer(&priv->obe.timer);
432 		}
433 	}
434 
435 	if (mask & KCS_BMC_EVENT_TYPE_IBF) {
436 		const bool enable = !!(state & KCS_BMC_EVENT_TYPE_IBF);
437 
438 		switch (kcs_bmc->channel) {
439 		case 1:
440 			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE1,
441 					   enable * LPC_HICR2_IBFIE1);
442 			return;
443 		case 2:
444 			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE2,
445 					   enable * LPC_HICR2_IBFIE2);
446 			return;
447 		case 3:
448 			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE3,
449 					   enable * LPC_HICR2_IBFIE3);
450 			return;
451 		case 4:
452 			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_IBFIE4,
453 					   enable * LPC_HICRB_IBFIE4);
454 			return;
455 		default:
456 			pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
457 			return;
458 		}
459 	}
460 }
461 
462 static const struct kcs_bmc_device_ops aspeed_kcs_ops = {
463 	.irq_mask_update = aspeed_kcs_irq_mask_update,
464 	.io_inputb = aspeed_kcs_inb,
465 	.io_outputb = aspeed_kcs_outb,
466 	.io_updateb = aspeed_kcs_updateb,
467 };
468 
469 static irqreturn_t aspeed_kcs_irq(int irq, void *arg)
470 {
471 	struct kcs_bmc_device *kcs_bmc = arg;
472 
473 	return kcs_bmc_handle_event(kcs_bmc);
474 }
475 
476 static int aspeed_kcs_config_downstream_irq(struct kcs_bmc_device *kcs_bmc,
477 			struct platform_device *pdev)
478 {
479 	struct device *dev = &pdev->dev;
480 	int irq;
481 
482 	irq = platform_get_irq(pdev, 0);
483 	if (irq < 0)
484 		return irq;
485 
486 	return devm_request_irq(dev, irq, aspeed_kcs_irq, IRQF_SHARED,
487 				dev_name(dev), kcs_bmc);
488 }
489 
490 static const struct kcs_ioreg ast_kcs_bmc_ioregs[KCS_CHANNEL_MAX] = {
491 	{ .idr = LPC_IDR1, .odr = LPC_ODR1, .str = LPC_STR1 },
492 	{ .idr = LPC_IDR2, .odr = LPC_ODR2, .str = LPC_STR2 },
493 	{ .idr = LPC_IDR3, .odr = LPC_ODR3, .str = LPC_STR3 },
494 	{ .idr = LPC_IDR4, .odr = LPC_ODR4, .str = LPC_STR4 },
495 };
496 
497 static int aspeed_kcs_of_get_channel(struct platform_device *pdev)
498 {
499 	struct device_node *np;
500 	struct kcs_ioreg ioreg;
501 	const __be32 *reg;
502 	int i;
503 
504 	np = pdev->dev.of_node;
505 
506 	/* Don't translate addresses, we want offsets for the regmaps */
507 	reg = of_get_address(np, 0, NULL, NULL);
508 	if (!reg)
509 		return -EINVAL;
510 	ioreg.idr = be32_to_cpup(reg);
511 
512 	reg = of_get_address(np, 1, NULL, NULL);
513 	if (!reg)
514 		return -EINVAL;
515 	ioreg.odr = be32_to_cpup(reg);
516 
517 	reg = of_get_address(np, 2, NULL, NULL);
518 	if (!reg)
519 		return -EINVAL;
520 	ioreg.str = be32_to_cpup(reg);
521 
522 	for (i = 0; i < ARRAY_SIZE(ast_kcs_bmc_ioregs); i++) {
523 		if (!memcmp(&ast_kcs_bmc_ioregs[i], &ioreg, sizeof(ioreg)))
524 			return i + 1;
525 	}
526 	return -EINVAL;
527 }
528 
529 static int
530 aspeed_kcs_of_get_io_address(struct platform_device *pdev, u32 addrs[2])
531 {
532 	int rc;
533 
534 	rc = of_property_read_variable_u32_array(pdev->dev.of_node,
535 						 "aspeed,lpc-io-reg",
536 						 addrs, 1, 2);
537 	if (rc < 0) {
538 		dev_err(&pdev->dev, "No valid 'aspeed,lpc-io-reg' configured\n");
539 		return rc;
540 	}
541 
542 	if (addrs[0] > 0xffff) {
543 		dev_err(&pdev->dev, "Invalid data address in 'aspeed,lpc-io-reg'\n");
544 		return -EINVAL;
545 	}
546 
547 	if (rc == 2 && addrs[1] > 0xffff) {
548 		dev_err(&pdev->dev, "Invalid status address in 'aspeed,lpc-io-reg'\n");
549 		return -EINVAL;
550 	}
551 
552 	return rc;
553 }
554 
555 static int aspeed_kcs_probe(struct platform_device *pdev)
556 {
557 	struct kcs_bmc_device *kcs_bmc;
558 	struct aspeed_kcs_bmc *priv;
559 	struct device_node *np;
560 	bool have_upstream_irq;
561 	u32 upstream_irq[2];
562 	int rc, channel;
563 	int nr_addrs;
564 	u32 addrs[2];
565 
566 	np = pdev->dev.of_node->parent;
567 	if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&
568 	    !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") &&
569 	    !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) {
570 		dev_err(&pdev->dev, "unsupported LPC device binding\n");
571 		return -ENODEV;
572 	}
573 
574 	channel = aspeed_kcs_of_get_channel(pdev);
575 	if (channel < 0)
576 		return channel;
577 
578 	nr_addrs = aspeed_kcs_of_get_io_address(pdev, addrs);
579 	if (nr_addrs < 0)
580 		return nr_addrs;
581 
582 	np = pdev->dev.of_node;
583 	rc = of_property_read_u32_array(np, "aspeed,lpc-interrupts", upstream_irq, 2);
584 	if (rc && rc != -EINVAL)
585 		return -EINVAL;
586 
587 	have_upstream_irq = !rc;
588 
589 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
590 	if (!priv)
591 		return -ENOMEM;
592 
593 	kcs_bmc = &priv->kcs_bmc;
594 	kcs_bmc->dev = &pdev->dev;
595 	kcs_bmc->channel = channel;
596 	kcs_bmc->ioreg = ast_kcs_bmc_ioregs[channel - 1];
597 	kcs_bmc->ops = &aspeed_kcs_ops;
598 
599 	priv->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
600 	if (IS_ERR(priv->map)) {
601 		dev_err(&pdev->dev, "Couldn't get regmap\n");
602 		return -ENODEV;
603 	}
604 
605 	spin_lock_init(&priv->obe.lock);
606 	priv->obe.remove = false;
607 	timer_setup(&priv->obe.timer, aspeed_kcs_check_obe, 0);
608 
609 	rc = aspeed_kcs_set_address(kcs_bmc, addrs, nr_addrs);
610 	if (rc)
611 		return rc;
612 
613 	/* Host to BMC IRQ */
614 	rc = aspeed_kcs_config_downstream_irq(kcs_bmc, pdev);
615 	if (rc)
616 		return rc;
617 
618 	/* BMC to Host IRQ */
619 	if (have_upstream_irq) {
620 		rc = aspeed_kcs_config_upstream_irq(priv, upstream_irq[0], upstream_irq[1]);
621 		if (rc < 0)
622 			return rc;
623 	} else {
624 		priv->upstream_irq.mode = aspeed_kcs_irq_none;
625 	}
626 
627 	platform_set_drvdata(pdev, priv);
628 
629 	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
630 	aspeed_kcs_enable_channel(kcs_bmc, true);
631 
632 	rc = kcs_bmc_add_device(&priv->kcs_bmc);
633 	if (rc) {
634 		dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);
635 		return rc;
636 	}
637 
638 	dev_info(&pdev->dev, "Initialised channel %d at 0x%x\n",
639 			kcs_bmc->channel, addrs[0]);
640 
641 	return 0;
642 }
643 
644 static void aspeed_kcs_remove(struct platform_device *pdev)
645 {
646 	struct aspeed_kcs_bmc *priv = platform_get_drvdata(pdev);
647 	struct kcs_bmc_device *kcs_bmc = &priv->kcs_bmc;
648 
649 	kcs_bmc_remove_device(kcs_bmc);
650 
651 	aspeed_kcs_enable_channel(kcs_bmc, false);
652 	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
653 
654 	/* Make sure it's proper dead */
655 	spin_lock_irq(&priv->obe.lock);
656 	priv->obe.remove = true;
657 	spin_unlock_irq(&priv->obe.lock);
658 	del_timer_sync(&priv->obe.timer);
659 }
660 
661 static const struct of_device_id ast_kcs_bmc_match[] = {
662 	{ .compatible = "aspeed,ast2400-kcs-bmc-v2" },
663 	{ .compatible = "aspeed,ast2500-kcs-bmc-v2" },
664 	{ .compatible = "aspeed,ast2600-kcs-bmc" },
665 	{ }
666 };
667 MODULE_DEVICE_TABLE(of, ast_kcs_bmc_match);
668 
669 static struct platform_driver ast_kcs_bmc_driver = {
670 	.driver = {
671 		.name           = DEVICE_NAME,
672 		.of_match_table = ast_kcs_bmc_match,
673 	},
674 	.probe  = aspeed_kcs_probe,
675 	.remove_new = aspeed_kcs_remove,
676 };
677 module_platform_driver(ast_kcs_bmc_driver);
678 
679 MODULE_LICENSE("GPL v2");
680 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
681 MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
682 MODULE_DESCRIPTION("Aspeed device interface to the KCS BMC device");
683