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/of_device.h>
18 #include <linux/platform_device.h>
19 #include <linux/poll.h>
20 #include <linux/regmap.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/timer.h>
24 
25 #include "kcs_bmc_device.h"
26 
27 
28 #define DEVICE_NAME     "ast-kcs-bmc"
29 
30 #define KCS_CHANNEL_MAX     4
31 
32 /*
33  * Field class descriptions
34  *
35  * LPCyE	Enable LPC channel y
36  * IBFIEy	Input Buffer Full IRQ Enable for LPC channel y
37  * IRQxEy	Assert SerIRQ x for LPC channel y (Deprecated, use IDyIRQX, IRQXEy)
38  * IDyIRQX	Use the specified 4-bit SerIRQ for LPC channel y
39  * SELyIRQX	SerIRQ polarity for LPC channel y (low: 0, high: 1)
40  * IRQXEy	Assert the SerIRQ specified in IDyIRQX for LPC channel y
41  */
42 
43 #define LPC_TYIRQX_LOW       0b00
44 #define LPC_TYIRQX_HIGH      0b01
45 #define LPC_TYIRQX_RSVD      0b10
46 #define LPC_TYIRQX_RISING    0b11
47 
48 #define LPC_HICR0            0x000
49 #define     LPC_HICR0_LPC3E          BIT(7)
50 #define     LPC_HICR0_LPC2E          BIT(6)
51 #define     LPC_HICR0_LPC1E          BIT(5)
52 #define LPC_HICR2            0x008
53 #define     LPC_HICR2_IBFIE3         BIT(3)
54 #define     LPC_HICR2_IBFIE2         BIT(2)
55 #define     LPC_HICR2_IBFIE1         BIT(1)
56 #define LPC_HICR4            0x010
57 #define     LPC_HICR4_LADR12AS       BIT(7)
58 #define     LPC_HICR4_KCSENBL        BIT(2)
59 #define LPC_SIRQCR0	     0x070
60 /* IRQ{12,1}E1 are deprecated as of AST2600 A3 but necessary for prior chips */
61 #define     LPC_SIRQCR0_IRQ12E1	     BIT(1)
62 #define     LPC_SIRQCR0_IRQ1E1	     BIT(0)
63 #define LPC_HICR5	     0x080
64 #define     LPC_HICR5_ID3IRQX_MASK   GENMASK(23, 20)
65 #define     LPC_HICR5_ID3IRQX_SHIFT  20
66 #define     LPC_HICR5_ID2IRQX_MASK   GENMASK(19, 16)
67 #define     LPC_HICR5_ID2IRQX_SHIFT  16
68 #define     LPC_HICR5_SEL3IRQX       BIT(15)
69 #define     LPC_HICR5_IRQXE3         BIT(14)
70 #define     LPC_HICR5_SEL2IRQX       BIT(13)
71 #define     LPC_HICR5_IRQXE2         BIT(12)
72 #define LPC_LADR3H           0x014
73 #define LPC_LADR3L           0x018
74 #define LPC_LADR12H          0x01C
75 #define LPC_LADR12L          0x020
76 #define LPC_IDR1             0x024
77 #define LPC_IDR2             0x028
78 #define LPC_IDR3             0x02C
79 #define LPC_ODR1             0x030
80 #define LPC_ODR2             0x034
81 #define LPC_ODR3             0x038
82 #define LPC_STR1             0x03C
83 #define LPC_STR2             0x040
84 #define LPC_STR3             0x044
85 #define LPC_HICRB            0x100
86 #define     LPC_HICRB_EN16LADR2      BIT(5)
87 #define     LPC_HICRB_EN16LADR1      BIT(4)
88 #define     LPC_HICRB_IBFIE4         BIT(1)
89 #define     LPC_HICRB_LPC4E          BIT(0)
90 #define LPC_HICRC            0x104
91 #define     LPC_HICRC_ID4IRQX_MASK   GENMASK(7, 4)
92 #define     LPC_HICRC_ID4IRQX_SHIFT  4
93 #define     LPC_HICRC_TY4IRQX_MASK   GENMASK(3, 2)
94 #define     LPC_HICRC_TY4IRQX_SHIFT  2
95 #define     LPC_HICRC_OBF4_AUTO_CLR  BIT(1)
96 #define     LPC_HICRC_IRQXE4         BIT(0)
97 #define LPC_LADR4            0x110
98 #define LPC_IDR4             0x114
99 #define LPC_ODR4             0x118
100 #define LPC_STR4             0x11C
101 #define LPC_LSADR12	     0x120
102 #define     LPC_LSADR12_LSADR2_MASK  GENMASK(31, 16)
103 #define     LPC_LSADR12_LSADR2_SHIFT 16
104 #define     LPC_LSADR12_LSADR1_MASK  GENMASK(15, 0)
105 #define     LPC_LSADR12_LSADR1_SHIFT 0
106 
107 #define OBE_POLL_PERIOD	     (HZ / 2)
108 
109 enum aspeed_kcs_irq_mode {
110 	aspeed_kcs_irq_none,
111 	aspeed_kcs_irq_serirq,
112 };
113 
114 struct aspeed_kcs_bmc {
115 	struct kcs_bmc_device kcs_bmc;
116 
117 	struct regmap *map;
118 
119 	struct {
120 		enum aspeed_kcs_irq_mode mode;
121 		int id;
122 	} upstream_irq;
123 
124 	struct {
125 		spinlock_t lock;
126 		bool remove;
127 		struct timer_list timer;
128 	} obe;
129 };
130 
131 struct aspeed_kcs_of_ops {
132 	int (*get_channel)(struct platform_device *pdev);
133 	int (*get_io_address)(struct platform_device *pdev, u32 addrs[2]);
134 };
135 
136 static inline struct aspeed_kcs_bmc *to_aspeed_kcs_bmc(struct kcs_bmc_device *kcs_bmc)
137 {
138 	return container_of(kcs_bmc, struct aspeed_kcs_bmc, kcs_bmc);
139 }
140 
141 static u8 aspeed_kcs_inb(struct kcs_bmc_device *kcs_bmc, u32 reg)
142 {
143 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
144 	u32 val = 0;
145 	int rc;
146 
147 	rc = regmap_read(priv->map, reg, &val);
148 	WARN(rc != 0, "regmap_read() failed: %d\n", rc);
149 
150 	return rc == 0 ? (u8) val : 0;
151 }
152 
153 static void aspeed_kcs_outb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 data)
154 {
155 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
156 	int rc;
157 
158 	rc = regmap_write(priv->map, reg, data);
159 	WARN(rc != 0, "regmap_write() failed: %d\n", rc);
160 
161 	/* Trigger the upstream IRQ on ODR writes, if enabled */
162 
163 	switch (reg) {
164 	case LPC_ODR1:
165 	case LPC_ODR2:
166 	case LPC_ODR3:
167 	case LPC_ODR4:
168 		break;
169 	default:
170 		return;
171 	}
172 
173 	if (priv->upstream_irq.mode != aspeed_kcs_irq_serirq)
174 		return;
175 
176 	switch (kcs_bmc->channel) {
177 	case 1:
178 		switch (priv->upstream_irq.id) {
179 		case 12:
180 			regmap_update_bits(priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ12E1,
181 					   LPC_SIRQCR0_IRQ12E1);
182 			break;
183 		case 1:
184 			regmap_update_bits(priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ1E1,
185 					   LPC_SIRQCR0_IRQ1E1);
186 			break;
187 		default:
188 			break;
189 		}
190 		break;
191 	case 2:
192 		regmap_update_bits(priv->map, LPC_HICR5, LPC_HICR5_IRQXE2, LPC_HICR5_IRQXE2);
193 		break;
194 	case 3:
195 		regmap_update_bits(priv->map, LPC_HICR5, LPC_HICR5_IRQXE3, LPC_HICR5_IRQXE3);
196 		break;
197 	case 4:
198 		regmap_update_bits(priv->map, LPC_HICRC, LPC_HICRC_IRQXE4, LPC_HICRC_IRQXE4);
199 		break;
200 	default:
201 		break;
202 	}
203 }
204 
205 static void aspeed_kcs_updateb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 val)
206 {
207 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
208 	int rc;
209 
210 	rc = regmap_update_bits(priv->map, reg, mask, val);
211 	WARN(rc != 0, "regmap_update_bits() failed: %d\n", rc);
212 }
213 
214 /*
215  * AST_usrGuide_KCS.pdf
216  * 2. Background:
217  *   we note D for Data, and C for Cmd/Status, default rules are
218  *     A. KCS1 / KCS2 ( D / C:X / X+4 )
219  *        D / C : CA0h / CA4h
220  *        D / C : CA8h / CACh
221  *     B. KCS3 ( D / C:XX2h / XX3h )
222  *        D / C : CA2h / CA3h
223  *        D / C : CB2h / CB3h
224  *     C. KCS4
225  *        D / C : CA4h / CA5h
226  */
227 static int aspeed_kcs_set_address(struct kcs_bmc_device *kcs_bmc, u32 addrs[2], int nr_addrs)
228 {
229 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
230 
231 	if (WARN_ON(nr_addrs < 1 || nr_addrs > 2))
232 		return -EINVAL;
233 
234 	switch (priv->kcs_bmc.channel) {
235 	case 1:
236 		regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, 0);
237 		regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8);
238 		regmap_write(priv->map, LPC_LADR12L, addrs[0] & 0xFF);
239 		if (nr_addrs == 2) {
240 			regmap_update_bits(priv->map, LPC_LSADR12, LPC_LSADR12_LSADR1_MASK,
241 					   addrs[1] << LPC_LSADR12_LSADR1_SHIFT);
242 
243 			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_EN16LADR1,
244 					   LPC_HICRB_EN16LADR1);
245 		}
246 		break;
247 
248 	case 2:
249 		regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, LPC_HICR4_LADR12AS);
250 		regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8);
251 		regmap_write(priv->map, LPC_LADR12L, addrs[0] & 0xFF);
252 		if (nr_addrs == 2) {
253 			regmap_update_bits(priv->map, LPC_LSADR12, LPC_LSADR12_LSADR2_MASK,
254 					   addrs[1] << LPC_LSADR12_LSADR2_SHIFT);
255 
256 			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_EN16LADR2,
257 					   LPC_HICRB_EN16LADR2);
258 		}
259 		break;
260 
261 	case 3:
262 		if (nr_addrs == 2) {
263 			dev_err(priv->kcs_bmc.dev,
264 				"Channel 3 only supports inferred status IO address\n");
265 			return -EINVAL;
266 		}
267 
268 		regmap_write(priv->map, LPC_LADR3H, addrs[0] >> 8);
269 		regmap_write(priv->map, LPC_LADR3L, addrs[0] & 0xFF);
270 		break;
271 
272 	case 4:
273 		if (nr_addrs == 1)
274 			regmap_write(priv->map, LPC_LADR4, ((addrs[0] + 1) << 16) | addrs[0]);
275 		else
276 			regmap_write(priv->map, LPC_LADR4, (addrs[1] << 16) | addrs[0]);
277 
278 		break;
279 
280 	default:
281 		return -EINVAL;
282 	}
283 
284 	return 0;
285 }
286 
287 static inline int aspeed_kcs_map_serirq_type(u32 dt_type)
288 {
289 	switch (dt_type) {
290 	case IRQ_TYPE_EDGE_RISING:
291 		return LPC_TYIRQX_RISING;
292 	case IRQ_TYPE_LEVEL_HIGH:
293 		return LPC_TYIRQX_HIGH;
294 	case IRQ_TYPE_LEVEL_LOW:
295 		return LPC_TYIRQX_LOW;
296 	default:
297 		return -EINVAL;
298 	}
299 }
300 
301 static int aspeed_kcs_config_upstream_irq(struct aspeed_kcs_bmc *priv, u32 id, u32 dt_type)
302 {
303 	unsigned int mask, val, hw_type;
304 	int ret;
305 
306 	if (id > 15)
307 		return -EINVAL;
308 
309 	ret = aspeed_kcs_map_serirq_type(dt_type);
310 	if (ret < 0)
311 		return ret;
312 	hw_type = ret;
313 
314 	priv->upstream_irq.mode = aspeed_kcs_irq_serirq;
315 	priv->upstream_irq.id = id;
316 
317 	switch (priv->kcs_bmc.channel) {
318 	case 1:
319 		/* Needs IRQxE1 rather than (ID1IRQX, SEL1IRQX, IRQXE1) before AST2600 A3 */
320 		break;
321 	case 2:
322 		if (!(hw_type == LPC_TYIRQX_LOW || hw_type == LPC_TYIRQX_HIGH))
323 			return -EINVAL;
324 
325 		mask = LPC_HICR5_SEL2IRQX | LPC_HICR5_ID2IRQX_MASK;
326 		val = (id << LPC_HICR5_ID2IRQX_SHIFT);
327 		val |= (hw_type == LPC_TYIRQX_HIGH) ? LPC_HICR5_SEL2IRQX : 0;
328 		regmap_update_bits(priv->map, LPC_HICR5, mask, val);
329 
330 		break;
331 	case 3:
332 		if (!(hw_type == LPC_TYIRQX_LOW || hw_type == LPC_TYIRQX_HIGH))
333 			return -EINVAL;
334 
335 		mask = LPC_HICR5_SEL3IRQX | LPC_HICR5_ID3IRQX_MASK;
336 		val = (id << LPC_HICR5_ID3IRQX_SHIFT);
337 		val |= (hw_type == LPC_TYIRQX_HIGH) ? LPC_HICR5_SEL3IRQX : 0;
338 		regmap_update_bits(priv->map, LPC_HICR5, mask, val);
339 
340 		break;
341 	case 4:
342 		mask = LPC_HICRC_ID4IRQX_MASK | LPC_HICRC_TY4IRQX_MASK | LPC_HICRC_OBF4_AUTO_CLR;
343 		val = (id << LPC_HICRC_ID4IRQX_SHIFT) | (hw_type << LPC_HICRC_TY4IRQX_SHIFT);
344 		regmap_update_bits(priv->map, LPC_HICRC, mask, val);
345 		break;
346 	default:
347 		dev_warn(priv->kcs_bmc.dev,
348 			 "SerIRQ configuration not supported on KCS channel %d\n",
349 			 priv->kcs_bmc.channel);
350 		return -EINVAL;
351 	}
352 
353 	return 0;
354 }
355 
356 static void aspeed_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enable)
357 {
358 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
359 
360 	switch (kcs_bmc->channel) {
361 	case 1:
362 		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC1E, enable * LPC_HICR0_LPC1E);
363 		return;
364 	case 2:
365 		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC2E, enable * LPC_HICR0_LPC2E);
366 		return;
367 	case 3:
368 		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC3E, enable * LPC_HICR0_LPC3E);
369 		regmap_update_bits(priv->map, LPC_HICR4,
370 				   LPC_HICR4_KCSENBL, enable * LPC_HICR4_KCSENBL);
371 		return;
372 	case 4:
373 		regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_LPC4E, enable * LPC_HICRB_LPC4E);
374 		return;
375 	default:
376 		pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
377 		return;
378 	}
379 }
380 
381 static void aspeed_kcs_check_obe(struct timer_list *timer)
382 {
383 	struct aspeed_kcs_bmc *priv = container_of(timer, struct aspeed_kcs_bmc, obe.timer);
384 	unsigned long flags;
385 	u8 str;
386 
387 	spin_lock_irqsave(&priv->obe.lock, flags);
388 	if (priv->obe.remove) {
389 		spin_unlock_irqrestore(&priv->obe.lock, flags);
390 		return;
391 	}
392 
393 	str = aspeed_kcs_inb(&priv->kcs_bmc, priv->kcs_bmc.ioreg.str);
394 	if (str & KCS_BMC_STR_OBF) {
395 		mod_timer(timer, jiffies + OBE_POLL_PERIOD);
396 		spin_unlock_irqrestore(&priv->obe.lock, flags);
397 		return;
398 	}
399 	spin_unlock_irqrestore(&priv->obe.lock, flags);
400 
401 	kcs_bmc_handle_event(&priv->kcs_bmc);
402 }
403 
404 static void aspeed_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 state)
405 {
406 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
407 
408 	/* We don't have an OBE IRQ, emulate it */
409 	if (mask & KCS_BMC_EVENT_TYPE_OBE) {
410 		if (KCS_BMC_EVENT_TYPE_OBE & state)
411 			mod_timer(&priv->obe.timer, jiffies + OBE_POLL_PERIOD);
412 		else
413 			del_timer(&priv->obe.timer);
414 	}
415 
416 	if (mask & KCS_BMC_EVENT_TYPE_IBF) {
417 		const bool enable = !!(state & KCS_BMC_EVENT_TYPE_IBF);
418 
419 		switch (kcs_bmc->channel) {
420 		case 1:
421 			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE1,
422 					   enable * LPC_HICR2_IBFIE1);
423 			return;
424 		case 2:
425 			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE2,
426 					   enable * LPC_HICR2_IBFIE2);
427 			return;
428 		case 3:
429 			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE3,
430 					   enable * LPC_HICR2_IBFIE3);
431 			return;
432 		case 4:
433 			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_IBFIE4,
434 					   enable * LPC_HICRB_IBFIE4);
435 			return;
436 		default:
437 			pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
438 			return;
439 		}
440 	}
441 }
442 
443 static const struct kcs_bmc_device_ops aspeed_kcs_ops = {
444 	.irq_mask_update = aspeed_kcs_irq_mask_update,
445 	.io_inputb = aspeed_kcs_inb,
446 	.io_outputb = aspeed_kcs_outb,
447 	.io_updateb = aspeed_kcs_updateb,
448 };
449 
450 static irqreturn_t aspeed_kcs_irq(int irq, void *arg)
451 {
452 	struct kcs_bmc_device *kcs_bmc = arg;
453 
454 	return kcs_bmc_handle_event(kcs_bmc);
455 }
456 
457 static int aspeed_kcs_config_downstream_irq(struct kcs_bmc_device *kcs_bmc,
458 			struct platform_device *pdev)
459 {
460 	struct device *dev = &pdev->dev;
461 	int irq;
462 
463 	irq = platform_get_irq(pdev, 0);
464 	if (irq < 0)
465 		return irq;
466 
467 	return devm_request_irq(dev, irq, aspeed_kcs_irq, IRQF_SHARED,
468 				dev_name(dev), kcs_bmc);
469 }
470 
471 static const struct kcs_ioreg ast_kcs_bmc_ioregs[KCS_CHANNEL_MAX] = {
472 	{ .idr = LPC_IDR1, .odr = LPC_ODR1, .str = LPC_STR1 },
473 	{ .idr = LPC_IDR2, .odr = LPC_ODR2, .str = LPC_STR2 },
474 	{ .idr = LPC_IDR3, .odr = LPC_ODR3, .str = LPC_STR3 },
475 	{ .idr = LPC_IDR4, .odr = LPC_ODR4, .str = LPC_STR4 },
476 };
477 
478 static int aspeed_kcs_of_v1_get_channel(struct platform_device *pdev)
479 {
480 	struct device_node *np;
481 	u32 channel;
482 	int rc;
483 
484 	np = pdev->dev.of_node;
485 
486 	rc = of_property_read_u32(np, "kcs_chan", &channel);
487 	if ((rc != 0) || (channel == 0 || channel > KCS_CHANNEL_MAX)) {
488 		dev_err(&pdev->dev, "no valid 'kcs_chan' configured\n");
489 		return -EINVAL;
490 	}
491 
492 	return channel;
493 }
494 
495 static int
496 aspeed_kcs_of_v1_get_io_address(struct platform_device *pdev, u32 addrs[2])
497 {
498 	int rc;
499 
500 	rc = of_property_read_u32(pdev->dev.of_node, "kcs_addr", addrs);
501 	if (rc || addrs[0] > 0xffff) {
502 		dev_err(&pdev->dev, "no valid 'kcs_addr' configured\n");
503 		return -EINVAL;
504 	}
505 
506 	return 1;
507 }
508 
509 static int aspeed_kcs_of_v2_get_channel(struct platform_device *pdev)
510 {
511 	struct device_node *np;
512 	struct kcs_ioreg ioreg;
513 	const __be32 *reg;
514 	int i;
515 
516 	np = pdev->dev.of_node;
517 
518 	/* Don't translate addresses, we want offsets for the regmaps */
519 	reg = of_get_address(np, 0, NULL, NULL);
520 	if (!reg)
521 		return -EINVAL;
522 	ioreg.idr = be32_to_cpup(reg);
523 
524 	reg = of_get_address(np, 1, NULL, NULL);
525 	if (!reg)
526 		return -EINVAL;
527 	ioreg.odr = be32_to_cpup(reg);
528 
529 	reg = of_get_address(np, 2, NULL, NULL);
530 	if (!reg)
531 		return -EINVAL;
532 	ioreg.str = be32_to_cpup(reg);
533 
534 	for (i = 0; i < ARRAY_SIZE(ast_kcs_bmc_ioregs); i++) {
535 		if (!memcmp(&ast_kcs_bmc_ioregs[i], &ioreg, sizeof(ioreg)))
536 			return i + 1;
537 	}
538 
539 	return -EINVAL;
540 }
541 
542 static int
543 aspeed_kcs_of_v2_get_io_address(struct platform_device *pdev, u32 addrs[2])
544 {
545 	int rc;
546 
547 	rc = of_property_read_variable_u32_array(pdev->dev.of_node,
548 						 "aspeed,lpc-io-reg",
549 						 addrs, 1, 2);
550 	if (rc < 0) {
551 		dev_err(&pdev->dev, "No valid 'aspeed,lpc-io-reg' configured\n");
552 		return rc;
553 	}
554 
555 	if (addrs[0] > 0xffff) {
556 		dev_err(&pdev->dev, "Invalid data address in 'aspeed,lpc-io-reg'\n");
557 		return -EINVAL;
558 	}
559 
560 	if (rc == 2 && addrs[1] > 0xffff) {
561 		dev_err(&pdev->dev, "Invalid status address in 'aspeed,lpc-io-reg'\n");
562 		return -EINVAL;
563 	}
564 
565 	return rc;
566 }
567 
568 static int aspeed_kcs_probe(struct platform_device *pdev)
569 {
570 	const struct aspeed_kcs_of_ops *ops;
571 	struct kcs_bmc_device *kcs_bmc;
572 	struct aspeed_kcs_bmc *priv;
573 	struct device_node *np;
574 	bool have_upstream_irq;
575 	u32 upstream_irq[2];
576 	int rc, channel;
577 	int nr_addrs;
578 	u32 addrs[2];
579 
580 	np = pdev->dev.of_node->parent;
581 	if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&
582 	    !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") &&
583 	    !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) {
584 		dev_err(&pdev->dev, "unsupported LPC device binding\n");
585 		return -ENODEV;
586 	}
587 
588 	ops = of_device_get_match_data(&pdev->dev);
589 	if (!ops)
590 		return -EINVAL;
591 
592 	channel = ops->get_channel(pdev);
593 	if (channel < 0)
594 		return channel;
595 
596 	nr_addrs = ops->get_io_address(pdev, addrs);
597 	if (nr_addrs < 0)
598 		return nr_addrs;
599 
600 	np = pdev->dev.of_node;
601 	rc = of_property_read_u32_array(np, "aspeed,lpc-interrupts", upstream_irq, 2);
602 	if (rc && rc != -EINVAL)
603 		return -EINVAL;
604 
605 	have_upstream_irq = !rc;
606 
607 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
608 	if (!priv)
609 		return -ENOMEM;
610 
611 	kcs_bmc = &priv->kcs_bmc;
612 	kcs_bmc->dev = &pdev->dev;
613 	kcs_bmc->channel = channel;
614 	kcs_bmc->ioreg = ast_kcs_bmc_ioregs[channel - 1];
615 	kcs_bmc->ops = &aspeed_kcs_ops;
616 
617 	priv->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
618 	if (IS_ERR(priv->map)) {
619 		dev_err(&pdev->dev, "Couldn't get regmap\n");
620 		return -ENODEV;
621 	}
622 
623 	spin_lock_init(&priv->obe.lock);
624 	priv->obe.remove = false;
625 	timer_setup(&priv->obe.timer, aspeed_kcs_check_obe, 0);
626 
627 	rc = aspeed_kcs_set_address(kcs_bmc, addrs, nr_addrs);
628 	if (rc)
629 		return rc;
630 
631 	/* Host to BMC IRQ */
632 	rc = aspeed_kcs_config_downstream_irq(kcs_bmc, pdev);
633 	if (rc)
634 		return rc;
635 
636 	/* BMC to Host IRQ */
637 	if (have_upstream_irq) {
638 		rc = aspeed_kcs_config_upstream_irq(priv, upstream_irq[0], upstream_irq[1]);
639 		if (rc < 0)
640 			return rc;
641 	} else {
642 		priv->upstream_irq.mode = aspeed_kcs_irq_none;
643 	}
644 
645 	platform_set_drvdata(pdev, priv);
646 
647 	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
648 	aspeed_kcs_enable_channel(kcs_bmc, true);
649 
650 	rc = kcs_bmc_add_device(&priv->kcs_bmc);
651 	if (rc) {
652 		dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);
653 		return rc;
654 	}
655 
656 	dev_info(&pdev->dev, "Initialised channel %d at 0x%x\n",
657 			kcs_bmc->channel, addrs[0]);
658 
659 	return 0;
660 }
661 
662 static int aspeed_kcs_remove(struct platform_device *pdev)
663 {
664 	struct aspeed_kcs_bmc *priv = platform_get_drvdata(pdev);
665 	struct kcs_bmc_device *kcs_bmc = &priv->kcs_bmc;
666 
667 	kcs_bmc_remove_device(kcs_bmc);
668 
669 	aspeed_kcs_enable_channel(kcs_bmc, false);
670 	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
671 
672 	/* Make sure it's proper dead */
673 	spin_lock_irq(&priv->obe.lock);
674 	priv->obe.remove = true;
675 	spin_unlock_irq(&priv->obe.lock);
676 	del_timer_sync(&priv->obe.timer);
677 
678 	return 0;
679 }
680 
681 static const struct aspeed_kcs_of_ops of_v1_ops = {
682 	.get_channel = aspeed_kcs_of_v1_get_channel,
683 	.get_io_address = aspeed_kcs_of_v1_get_io_address,
684 };
685 
686 static const struct aspeed_kcs_of_ops of_v2_ops = {
687 	.get_channel = aspeed_kcs_of_v2_get_channel,
688 	.get_io_address = aspeed_kcs_of_v2_get_io_address,
689 };
690 
691 static const struct of_device_id ast_kcs_bmc_match[] = {
692 	{ .compatible = "aspeed,ast2400-kcs-bmc", .data = &of_v1_ops },
693 	{ .compatible = "aspeed,ast2500-kcs-bmc", .data = &of_v1_ops },
694 	{ .compatible = "aspeed,ast2400-kcs-bmc-v2", .data = &of_v2_ops },
695 	{ .compatible = "aspeed,ast2500-kcs-bmc-v2", .data = &of_v2_ops },
696 	{ }
697 };
698 MODULE_DEVICE_TABLE(of, ast_kcs_bmc_match);
699 
700 static struct platform_driver ast_kcs_bmc_driver = {
701 	.driver = {
702 		.name           = DEVICE_NAME,
703 		.of_match_table = ast_kcs_bmc_match,
704 	},
705 	.probe  = aspeed_kcs_probe,
706 	.remove = aspeed_kcs_remove,
707 };
708 module_platform_driver(ast_kcs_bmc_driver);
709 
710 MODULE_LICENSE("GPL v2");
711 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
712 MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
713 MODULE_DESCRIPTION("Aspeed device interface to the KCS BMC device");
714