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
108enum aspeed_kcs_irq_mode {
109 aspeed_kcs_irq_none,
110 aspeed_kcs_irq_serirq,
111};
112
113struct 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
130static 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
135static 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(map: priv->map, reg, val: &val);
142 WARN(rc != 0, "regmap_read() failed: %d\n", rc);
143
144 return rc == 0 ? (u8) val : 0;
145}
146
147static 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(map: priv->map, reg, val: 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(map: priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ12E1,
175 LPC_SIRQCR0_IRQ12E1);
176 break;
177 case 1:
178 regmap_update_bits(map: 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(map: priv->map, LPC_HICR5, LPC_HICR5_IRQXE2, LPC_HICR5_IRQXE2);
187 break;
188 case 3:
189 regmap_update_bits(map: priv->map, LPC_HICR5, LPC_HICR5_IRQXE3, LPC_HICR5_IRQXE3);
190 break;
191 case 4:
192 regmap_update_bits(map: priv->map, LPC_HICRC, LPC_HICRC_IRQXE4, LPC_HICRC_IRQXE4);
193 break;
194 default:
195 break;
196 }
197}
198
199static 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(map: 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 */
228static 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(map: priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, val: 0);
238 regmap_write(map: priv->map, LPC_LADR12H, val: addrs[0] >> 8);
239 regmap_write(map: priv->map, LPC_LADR12L, val: addrs[0] & 0xFF);
240 if (nr_addrs == 2) {
241 regmap_update_bits(map: priv->map, LPC_LSADR12, LPC_LSADR12_LSADR1_MASK,
242 val: addrs[1] << LPC_LSADR12_LSADR1_SHIFT);
243
244 regmap_update_bits(map: priv->map, LPC_HICRB, LPC_HICRB_EN16LADR1,
245 LPC_HICRB_EN16LADR1);
246 }
247 break;
248
249 case 2:
250 regmap_update_bits(map: priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, LPC_HICR4_LADR12AS);
251 regmap_write(map: priv->map, LPC_LADR12H, val: addrs[0] >> 8);
252 regmap_write(map: priv->map, LPC_LADR12L, val: addrs[0] & 0xFF);
253 if (nr_addrs == 2) {
254 regmap_update_bits(map: priv->map, LPC_LSADR12, LPC_LSADR12_LSADR2_MASK,
255 val: addrs[1] << LPC_LSADR12_LSADR2_SHIFT);
256
257 regmap_update_bits(map: 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(map: priv->map, LPC_LADR3H, val: addrs[0] >> 8);
270 regmap_write(map: priv->map, LPC_LADR3L, val: addrs[0] & 0xFF);
271 break;
272
273 case 4:
274 if (nr_addrs == 1)
275 regmap_write(map: priv->map, LPC_LADR4, val: ((addrs[0] + 1) << 16) | addrs[0]);
276 else
277 regmap_write(map: priv->map, LPC_LADR4, val: (addrs[1] << 16) | addrs[0]);
278
279 break;
280
281 default:
282 return -EINVAL;
283 }
284
285 return 0;
286}
287
288static 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
302static 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(map: 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(map: 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(map: 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
357static 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(map: priv->map, LPC_HICR0, LPC_HICR0_LPC1E, val: enable * LPC_HICR0_LPC1E);
364 return;
365 case 2:
366 regmap_update_bits(map: priv->map, LPC_HICR0, LPC_HICR0_LPC2E, val: enable * LPC_HICR0_LPC2E);
367 return;
368 case 3:
369 regmap_update_bits(map: priv->map, LPC_HICR0, LPC_HICR0_LPC3E, val: enable * LPC_HICR0_LPC3E);
370 regmap_update_bits(map: priv->map, LPC_HICR4,
371 LPC_HICR4_KCSENBL, val: enable * LPC_HICR4_KCSENBL);
372 return;
373 case 4:
374 regmap_update_bits(map: priv->map, LPC_HICRB, LPC_HICRB_LPC4E, val: enable * LPC_HICRB_LPC4E);
375 return;
376 default:
377 pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
378 return;
379 }
380}
381
382static 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(lock: &priv->obe.lock, flags);
391 return;
392 }
393
394 str = aspeed_kcs_inb(kcs_bmc: &priv->kcs_bmc, reg: priv->kcs_bmc.ioreg.str);
395 if (str & KCS_BMC_STR_OBF) {
396 mod_timer(timer, expires: jiffies + OBE_POLL_PERIOD);
397 spin_unlock_irqrestore(lock: &priv->obe.lock, flags);
398 return;
399 }
400 spin_unlock_irqrestore(lock: &priv->obe.lock, flags);
401
402 kcs_bmc_handle_event(kcs_bmc: &priv->kcs_bmc);
403}
404
405static 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(timer: &priv->obe.timer, expires: jiffies + OBE_POLL_PERIOD);
430 } else {
431 del_timer(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(map: priv->map, LPC_HICR2, LPC_HICR2_IBFIE1,
441 val: enable * LPC_HICR2_IBFIE1);
442 return;
443 case 2:
444 regmap_update_bits(map: priv->map, LPC_HICR2, LPC_HICR2_IBFIE2,
445 val: enable * LPC_HICR2_IBFIE2);
446 return;
447 case 3:
448 regmap_update_bits(map: priv->map, LPC_HICR2, LPC_HICR2_IBFIE3,
449 val: enable * LPC_HICR2_IBFIE3);
450 return;
451 case 4:
452 regmap_update_bits(map: priv->map, LPC_HICRB, LPC_HICRB_IBFIE4,
453 val: 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
462static 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
469static 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
476static 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, handler: aspeed_kcs_irq, IRQF_SHARED,
487 devname: dev_name(dev), dev_id: kcs_bmc);
488}
489
490static 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
497static 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(dev: np, index: 0, NULL, NULL);
508 if (!reg)
509 return -EINVAL;
510 ioreg.idr = be32_to_cpup(p: reg);
511
512 reg = of_get_address(dev: np, index: 1, NULL, NULL);
513 if (!reg)
514 return -EINVAL;
515 ioreg.odr = be32_to_cpup(p: reg);
516
517 reg = of_get_address(dev: np, index: 2, NULL, NULL);
518 if (!reg)
519 return -EINVAL;
520 ioreg.str = be32_to_cpup(p: reg);
521
522 for (i = 0; i < ARRAY_SIZE(ast_kcs_bmc_ioregs); i++) {
523 if (!memcmp(p: &ast_kcs_bmc_ioregs[i], q: &ioreg, size: sizeof(ioreg)))
524 return i + 1;
525 }
526 return -EINVAL;
527}
528
529static int
530aspeed_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(np: pdev->dev.of_node,
535 propname: "aspeed,lpc-io-reg",
536 out_values: addrs, sz_min: 1, sz_max: 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
555static 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(device: np, "aspeed,ast2400-lpc-v2") &&
568 !of_device_is_compatible(device: np, "aspeed,ast2500-lpc-v2") &&
569 !of_device_is_compatible(device: 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, propname: "aspeed,lpc-interrupts", out_values: upstream_irq, sz: 2);
584 if (rc && rc != -EINVAL)
585 return -EINVAL;
586
587 have_upstream_irq = !rc;
588
589 priv = devm_kzalloc(dev: &pdev->dev, size: 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(np: pdev->dev.parent->of_node);
600 if (IS_ERR(ptr: 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, id: upstream_irq[0], dt_type: 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, data: priv);
628
629 aspeed_kcs_irq_mask_update(kcs_bmc, mask: (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), state: 0);
630 aspeed_kcs_enable_channel(kcs_bmc, enable: true);
631
632 rc = kcs_bmc_add_device(kcs_bmc: &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
644static int 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, enable: false);
652 aspeed_kcs_irq_mask_update(kcs_bmc, mask: (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), state: 0);
653
654 /* Make sure it's proper dead */
655 spin_lock_irq(lock: &priv->obe.lock);
656 priv->obe.remove = true;
657 spin_unlock_irq(lock: &priv->obe.lock);
658 del_timer_sync(timer: &priv->obe.timer);
659
660 return 0;
661}
662
663static const struct of_device_id ast_kcs_bmc_match[] = {
664 { .compatible = "aspeed,ast2400-kcs-bmc-v2" },
665 { .compatible = "aspeed,ast2500-kcs-bmc-v2" },
666 { .compatible = "aspeed,ast2600-kcs-bmc" },
667 { }
668};
669MODULE_DEVICE_TABLE(of, ast_kcs_bmc_match);
670
671static struct platform_driver ast_kcs_bmc_driver = {
672 .driver = {
673 .name = DEVICE_NAME,
674 .of_match_table = ast_kcs_bmc_match,
675 },
676 .probe = aspeed_kcs_probe,
677 .remove = aspeed_kcs_remove,
678};
679module_platform_driver(ast_kcs_bmc_driver);
680
681MODULE_LICENSE("GPL v2");
682MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
683MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
684MODULE_DESCRIPTION("Aspeed device interface to the KCS BMC device");
685

source code of linux/drivers/char/ipmi/kcs_bmc_aspeed.c