1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (c) 2012-2017 ASPEED Technology Inc.
3 // Copyright (c) 2018-2021 Intel Corporation
4 
5 #include <asm/unaligned.h>
6 
7 #include <linux/bitfield.h>
8 #include <linux/clk.h>
9 #include <linux/clkdev.h>
10 #include <linux/clk-provider.h>
11 #include <linux/delay.h>
12 #include <linux/interrupt.h>
13 #include <linux/io.h>
14 #include <linux/iopoll.h>
15 #include <linux/jiffies.h>
16 #include <linux/math.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/peci.h>
20 #include <linux/platform_device.h>
21 #include <linux/reset.h>
22 
23 /* ASPEED PECI Registers */
24 /* Control Register */
25 #define ASPEED_PECI_CTRL			0x00
26 #define   ASPEED_PECI_CTRL_SAMPLING_MASK	GENMASK(19, 16)
27 #define   ASPEED_PECI_CTRL_RD_MODE_MASK		GENMASK(13, 12)
28 #define     ASPEED_PECI_CTRL_RD_MODE_DBG	BIT(13)
29 #define     ASPEED_PECI_CTRL_RD_MODE_COUNT	BIT(12)
30 #define   ASPEED_PECI_CTRL_CLK_SRC_HCLK		BIT(11)
31 #define   ASPEED_PECI_CTRL_CLK_DIV_MASK		GENMASK(10, 8)
32 #define   ASPEED_PECI_CTRL_INVERT_OUT		BIT(7)
33 #define   ASPEED_PECI_CTRL_INVERT_IN		BIT(6)
34 #define   ASPEED_PECI_CTRL_BUS_CONTENTION_EN	BIT(5)
35 #define   ASPEED_PECI_CTRL_PECI_EN		BIT(4)
36 #define   ASPEED_PECI_CTRL_PECI_CLK_EN		BIT(0)
37 
38 /* Timing Negotiation Register */
39 #define ASPEED_PECI_TIMING_NEGOTIATION		0x04
40 #define   ASPEED_PECI_T_NEGO_MSG_MASK		GENMASK(15, 8)
41 #define   ASPEED_PECI_T_NEGO_ADDR_MASK		GENMASK(7, 0)
42 
43 /* Command Register */
44 #define ASPEED_PECI_CMD				0x08
45 #define   ASPEED_PECI_CMD_PIN_MONITORING	BIT(31)
46 #define   ASPEED_PECI_CMD_STS_MASK		GENMASK(27, 24)
47 #define     ASPEED_PECI_CMD_STS_ADDR_T_NEGO	0x3
48 #define   ASPEED_PECI_CMD_IDLE_MASK		\
49 	  (ASPEED_PECI_CMD_STS_MASK | ASPEED_PECI_CMD_PIN_MONITORING)
50 #define   ASPEED_PECI_CMD_FIRE			BIT(0)
51 
52 /* Read/Write Length Register */
53 #define ASPEED_PECI_RW_LENGTH			0x0c
54 #define   ASPEED_PECI_AW_FCS_EN			BIT(31)
55 #define   ASPEED_PECI_RD_LEN_MASK		GENMASK(23, 16)
56 #define   ASPEED_PECI_WR_LEN_MASK		GENMASK(15, 8)
57 #define   ASPEED_PECI_TARGET_ADDR_MASK		GENMASK(7, 0)
58 
59 /* Expected FCS Data Register */
60 #define ASPEED_PECI_EXPECTED_FCS		0x10
61 #define   ASPEED_PECI_EXPECTED_RD_FCS_MASK	GENMASK(23, 16)
62 #define   ASPEED_PECI_EXPECTED_AW_FCS_AUTO_MASK	GENMASK(15, 8)
63 #define   ASPEED_PECI_EXPECTED_WR_FCS_MASK	GENMASK(7, 0)
64 
65 /* Captured FCS Data Register */
66 #define ASPEED_PECI_CAPTURED_FCS		0x14
67 #define   ASPEED_PECI_CAPTURED_RD_FCS_MASK	GENMASK(23, 16)
68 #define   ASPEED_PECI_CAPTURED_WR_FCS_MASK	GENMASK(7, 0)
69 
70 /* Interrupt Register */
71 #define ASPEED_PECI_INT_CTRL			0x18
72 #define   ASPEED_PECI_TIMING_NEGO_SEL_MASK	GENMASK(31, 30)
73 #define     ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO	0
74 #define     ASPEED_PECI_2ND_BIT_OF_ADDR_NEGO	1
75 #define     ASPEED_PECI_MESSAGE_NEGO		2
76 #define   ASPEED_PECI_INT_MASK			GENMASK(4, 0)
77 #define     ASPEED_PECI_INT_BUS_TIMEOUT		BIT(4)
78 #define     ASPEED_PECI_INT_BUS_CONTENTION	BIT(3)
79 #define     ASPEED_PECI_INT_WR_FCS_BAD		BIT(2)
80 #define     ASPEED_PECI_INT_WR_FCS_ABORT	BIT(1)
81 #define     ASPEED_PECI_INT_CMD_DONE		BIT(0)
82 
83 /* Interrupt Status Register */
84 #define ASPEED_PECI_INT_STS			0x1c
85 #define   ASPEED_PECI_INT_TIMING_RESULT_MASK	GENMASK(29, 16)
86 	  /* bits[4..0]: Same bit fields in the 'Interrupt Register' */
87 
88 /* Rx/Tx Data Buffer Registers */
89 #define ASPEED_PECI_WR_DATA0			0x20
90 #define ASPEED_PECI_WR_DATA1			0x24
91 #define ASPEED_PECI_WR_DATA2			0x28
92 #define ASPEED_PECI_WR_DATA3			0x2c
93 #define ASPEED_PECI_RD_DATA0			0x30
94 #define ASPEED_PECI_RD_DATA1			0x34
95 #define ASPEED_PECI_RD_DATA2			0x38
96 #define ASPEED_PECI_RD_DATA3			0x3c
97 #define ASPEED_PECI_WR_DATA4			0x40
98 #define ASPEED_PECI_WR_DATA5			0x44
99 #define ASPEED_PECI_WR_DATA6			0x48
100 #define ASPEED_PECI_WR_DATA7			0x4c
101 #define ASPEED_PECI_RD_DATA4			0x50
102 #define ASPEED_PECI_RD_DATA5			0x54
103 #define ASPEED_PECI_RD_DATA6			0x58
104 #define ASPEED_PECI_RD_DATA7			0x5c
105 #define   ASPEED_PECI_DATA_BUF_SIZE_MAX		32
106 
107 /* Timing Negotiation */
108 #define ASPEED_PECI_CLK_FREQUENCY_MIN		2000
109 #define ASPEED_PECI_CLK_FREQUENCY_DEFAULT	1000000
110 #define ASPEED_PECI_CLK_FREQUENCY_MAX		2000000
111 #define ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT	8
112 /* Timeout */
113 #define ASPEED_PECI_IDLE_CHECK_TIMEOUT_US	(50 * USEC_PER_MSEC)
114 #define ASPEED_PECI_IDLE_CHECK_INTERVAL_US	(10 * USEC_PER_MSEC)
115 #define ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT	1000
116 #define ASPEED_PECI_CMD_TIMEOUT_MS_MAX		1000
117 
118 #define ASPEED_PECI_CLK_DIV1(msg_timing) (4 * (msg_timing) + 1)
119 #define ASPEED_PECI_CLK_DIV2(clk_div_exp) BIT(clk_div_exp)
120 #define ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp) \
121 	(4 * ASPEED_PECI_CLK_DIV1(msg_timing) * ASPEED_PECI_CLK_DIV2(clk_div_exp))
122 
123 struct aspeed_peci {
124 	struct peci_controller *controller;
125 	struct device *dev;
126 	void __iomem *base;
127 	struct reset_control *rst;
128 	int irq;
129 	spinlock_t lock; /* to sync completion status handling */
130 	struct completion xfer_complete;
131 	struct clk *clk;
132 	u32 clk_frequency;
133 	u32 status;
134 	u32 cmd_timeout_ms;
135 };
136 
137 struct clk_aspeed_peci {
138 	struct clk_hw hw;
139 	struct aspeed_peci *aspeed_peci;
140 };
141 
142 static void aspeed_peci_controller_enable(struct aspeed_peci *priv)
143 {
144 	u32 val = readl(priv->base + ASPEED_PECI_CTRL);
145 
146 	val |= ASPEED_PECI_CTRL_PECI_CLK_EN;
147 	val |= ASPEED_PECI_CTRL_PECI_EN;
148 
149 	writel(val, priv->base + ASPEED_PECI_CTRL);
150 }
151 
152 static void aspeed_peci_init_regs(struct aspeed_peci *priv)
153 {
154 	u32 val;
155 
156 	/* Clear interrupts */
157 	writel(ASPEED_PECI_INT_MASK, priv->base + ASPEED_PECI_INT_STS);
158 
159 	/* Set timing negotiation mode and enable interrupts */
160 	val = FIELD_PREP(ASPEED_PECI_TIMING_NEGO_SEL_MASK, ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO);
161 	val |= ASPEED_PECI_INT_MASK;
162 	writel(val, priv->base + ASPEED_PECI_INT_CTRL);
163 
164 	val = FIELD_PREP(ASPEED_PECI_CTRL_SAMPLING_MASK, ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT);
165 	writel(val, priv->base + ASPEED_PECI_CTRL);
166 }
167 
168 static int aspeed_peci_check_idle(struct aspeed_peci *priv)
169 {
170 	u32 cmd_sts = readl(priv->base + ASPEED_PECI_CMD);
171 	int ret;
172 
173 	/*
174 	 * Under normal circumstances, we expect to be idle here.
175 	 * In case there were any errors/timeouts that led to the situation
176 	 * where the hardware is not in idle state - we need to reset and
177 	 * reinitialize it to avoid potential controller hang.
178 	 */
179 	if (FIELD_GET(ASPEED_PECI_CMD_STS_MASK, cmd_sts)) {
180 		ret = reset_control_assert(priv->rst);
181 		if (ret) {
182 			dev_err(priv->dev, "cannot assert reset control\n");
183 			return ret;
184 		}
185 
186 		ret = reset_control_deassert(priv->rst);
187 		if (ret) {
188 			dev_err(priv->dev, "cannot deassert reset control\n");
189 			return ret;
190 		}
191 
192 		aspeed_peci_init_regs(priv);
193 
194 		ret = clk_set_rate(priv->clk, priv->clk_frequency);
195 		if (ret < 0) {
196 			dev_err(priv->dev, "cannot set clock frequency\n");
197 			return ret;
198 		}
199 
200 		aspeed_peci_controller_enable(priv);
201 	}
202 
203 	return readl_poll_timeout(priv->base + ASPEED_PECI_CMD,
204 				  cmd_sts,
205 				  !(cmd_sts & ASPEED_PECI_CMD_IDLE_MASK),
206 				  ASPEED_PECI_IDLE_CHECK_INTERVAL_US,
207 				  ASPEED_PECI_IDLE_CHECK_TIMEOUT_US);
208 }
209 
210 static int aspeed_peci_xfer(struct peci_controller *controller,
211 			    u8 addr, struct peci_request *req)
212 {
213 	struct aspeed_peci *priv = dev_get_drvdata(controller->dev.parent);
214 	unsigned long timeout = msecs_to_jiffies(priv->cmd_timeout_ms);
215 	u32 peci_head;
216 	int ret, i;
217 
218 	if (req->tx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX ||
219 	    req->rx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX)
220 		return -EINVAL;
221 
222 	/* Check command sts and bus idle state */
223 	ret = aspeed_peci_check_idle(priv);
224 	if (ret)
225 		return ret; /* -ETIMEDOUT */
226 
227 	spin_lock_irq(&priv->lock);
228 	reinit_completion(&priv->xfer_complete);
229 
230 	peci_head = FIELD_PREP(ASPEED_PECI_TARGET_ADDR_MASK, addr) |
231 		    FIELD_PREP(ASPEED_PECI_WR_LEN_MASK, req->tx.len) |
232 		    FIELD_PREP(ASPEED_PECI_RD_LEN_MASK, req->rx.len);
233 
234 	writel(peci_head, priv->base + ASPEED_PECI_RW_LENGTH);
235 
236 	for (i = 0; i < req->tx.len; i += 4) {
237 		u32 reg = (i < 16 ? ASPEED_PECI_WR_DATA0 : ASPEED_PECI_WR_DATA4) + i % 16;
238 
239 		writel(get_unaligned_le32(&req->tx.buf[i]), priv->base + reg);
240 	}
241 
242 #if IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
243 	dev_dbg(priv->dev, "HEAD : %#08x\n", peci_head);
244 	print_hex_dump_bytes("TX : ", DUMP_PREFIX_NONE, req->tx.buf, req->tx.len);
245 #endif
246 
247 	priv->status = 0;
248 	writel(ASPEED_PECI_CMD_FIRE, priv->base + ASPEED_PECI_CMD);
249 	spin_unlock_irq(&priv->lock);
250 
251 	ret = wait_for_completion_interruptible_timeout(&priv->xfer_complete, timeout);
252 	if (ret < 0)
253 		return ret;
254 
255 	if (ret == 0) {
256 		dev_dbg(priv->dev, "timeout waiting for a response\n");
257 		return -ETIMEDOUT;
258 	}
259 
260 	spin_lock_irq(&priv->lock);
261 
262 	if (priv->status != ASPEED_PECI_INT_CMD_DONE) {
263 		spin_unlock_irq(&priv->lock);
264 		dev_dbg(priv->dev, "no valid response, status: %#02x\n", priv->status);
265 		return -EIO;
266 	}
267 
268 	spin_unlock_irq(&priv->lock);
269 
270 	/*
271 	 * We need to use dword reads for register access, make sure that the
272 	 * buffer size is multiple of 4-bytes.
273 	 */
274 	BUILD_BUG_ON(PECI_REQUEST_MAX_BUF_SIZE % 4);
275 
276 	for (i = 0; i < req->rx.len; i += 4) {
277 		u32 reg = (i < 16 ? ASPEED_PECI_RD_DATA0 : ASPEED_PECI_RD_DATA4) + i % 16;
278 		u32 rx_data = readl(priv->base + reg);
279 
280 		put_unaligned_le32(rx_data, &req->rx.buf[i]);
281 	}
282 
283 #if IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
284 	print_hex_dump_bytes("RX : ", DUMP_PREFIX_NONE, req->rx.buf, req->rx.len);
285 #endif
286 	return 0;
287 }
288 
289 static irqreturn_t aspeed_peci_irq_handler(int irq, void *arg)
290 {
291 	struct aspeed_peci *priv = arg;
292 	u32 status;
293 
294 	spin_lock(&priv->lock);
295 	status = readl(priv->base + ASPEED_PECI_INT_STS);
296 	writel(status, priv->base + ASPEED_PECI_INT_STS);
297 	priv->status |= (status & ASPEED_PECI_INT_MASK);
298 
299 	/*
300 	 * All commands should be ended up with a ASPEED_PECI_INT_CMD_DONE bit
301 	 * set even in an error case.
302 	 */
303 	if (status & ASPEED_PECI_INT_CMD_DONE)
304 		complete(&priv->xfer_complete);
305 
306 	writel(0, priv->base + ASPEED_PECI_CMD);
307 
308 	spin_unlock(&priv->lock);
309 
310 	return IRQ_HANDLED;
311 }
312 
313 static void clk_aspeed_peci_find_div_values(unsigned long rate, int *msg_timing, int *clk_div_exp)
314 {
315 	unsigned long best_diff = ~0ul, diff;
316 	int msg_timing_temp, clk_div_exp_temp, i, j;
317 
318 	for (i = 1; i <= 255; i++)
319 		for (j = 0; j < 8; j++) {
320 			diff = abs(rate - ASPEED_PECI_CLK_DIV1(i) * ASPEED_PECI_CLK_DIV2(j));
321 			if (diff < best_diff) {
322 				msg_timing_temp = i;
323 				clk_div_exp_temp = j;
324 				best_diff = diff;
325 			}
326 		}
327 
328 	*msg_timing = msg_timing_temp;
329 	*clk_div_exp = clk_div_exp_temp;
330 }
331 
332 static int clk_aspeed_peci_get_div(unsigned long rate, const unsigned long *prate)
333 {
334 	unsigned long this_rate = *prate / (4 * rate);
335 	int msg_timing, clk_div_exp;
336 
337 	clk_aspeed_peci_find_div_values(this_rate, &msg_timing, &clk_div_exp);
338 
339 	return ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp);
340 }
341 
342 static int clk_aspeed_peci_set_rate(struct clk_hw *hw, unsigned long rate,
343 				    unsigned long prate)
344 {
345 	struct clk_aspeed_peci *peci_clk = container_of(hw, struct clk_aspeed_peci, hw);
346 	struct aspeed_peci *aspeed_peci = peci_clk->aspeed_peci;
347 	unsigned long this_rate = prate / (4 * rate);
348 	int clk_div_exp, msg_timing;
349 	u32 val;
350 
351 	clk_aspeed_peci_find_div_values(this_rate, &msg_timing, &clk_div_exp);
352 
353 	val = readl(aspeed_peci->base + ASPEED_PECI_CTRL);
354 	val |= FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK, clk_div_exp);
355 	writel(val, aspeed_peci->base + ASPEED_PECI_CTRL);
356 
357 	val = FIELD_PREP(ASPEED_PECI_T_NEGO_MSG_MASK, msg_timing);
358 	val |= FIELD_PREP(ASPEED_PECI_T_NEGO_ADDR_MASK, msg_timing);
359 	writel(val, aspeed_peci->base + ASPEED_PECI_TIMING_NEGOTIATION);
360 
361 	return 0;
362 }
363 
364 static long clk_aspeed_peci_round_rate(struct clk_hw *hw, unsigned long rate,
365 				       unsigned long *prate)
366 {
367 	int div = clk_aspeed_peci_get_div(rate, prate);
368 
369 	return DIV_ROUND_UP_ULL(*prate, div);
370 }
371 
372 static unsigned long clk_aspeed_peci_recalc_rate(struct clk_hw *hw, unsigned long prate)
373 {
374 	struct clk_aspeed_peci *peci_clk = container_of(hw, struct clk_aspeed_peci, hw);
375 	struct aspeed_peci *aspeed_peci = peci_clk->aspeed_peci;
376 	int div, msg_timing, addr_timing, clk_div_exp;
377 	u32 reg;
378 
379 	reg = readl(aspeed_peci->base + ASPEED_PECI_TIMING_NEGOTIATION);
380 	msg_timing = FIELD_GET(ASPEED_PECI_T_NEGO_MSG_MASK, reg);
381 	addr_timing = FIELD_GET(ASPEED_PECI_T_NEGO_ADDR_MASK, reg);
382 
383 	if (msg_timing != addr_timing)
384 		return 0;
385 
386 	reg = readl(aspeed_peci->base + ASPEED_PECI_CTRL);
387 	clk_div_exp = FIELD_GET(ASPEED_PECI_CTRL_CLK_DIV_MASK, reg);
388 
389 	div = ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp);
390 
391 	return DIV_ROUND_UP_ULL(prate, div);
392 }
393 
394 static const struct clk_ops clk_aspeed_peci_ops = {
395 	.set_rate = clk_aspeed_peci_set_rate,
396 	.round_rate = clk_aspeed_peci_round_rate,
397 	.recalc_rate = clk_aspeed_peci_recalc_rate,
398 };
399 
400 /*
401  * PECI HW contains a clock divider which is a combination of:
402  *  div0: 4 (fixed divider)
403  *  div1: x + 1
404  *  div2: 1 << y
405  * In other words, out_clk = in_clk / (div0 * div1 * div2)
406  * The resulting frequency is used by PECI Controller to drive the PECI bus to
407  * negotiate optimal transfer rate.
408  */
409 static struct clk *devm_aspeed_peci_register_clk_div(struct device *dev, struct clk *parent,
410 						     struct aspeed_peci *priv)
411 {
412 	struct clk_aspeed_peci *peci_clk;
413 	struct clk_init_data init;
414 	const char *parent_name;
415 	char name[32];
416 	int ret;
417 
418 	snprintf(name, sizeof(name), "%s_div", dev_name(dev));
419 
420 	parent_name = __clk_get_name(parent);
421 
422 	init.ops = &clk_aspeed_peci_ops;
423 	init.name = name;
424 	init.parent_names = (const char* []) { parent_name };
425 	init.num_parents = 1;
426 	init.flags = 0;
427 
428 	peci_clk = devm_kzalloc(dev, sizeof(struct clk_aspeed_peci), GFP_KERNEL);
429 	if (!peci_clk)
430 		return ERR_PTR(-ENOMEM);
431 
432 	peci_clk->hw.init = &init;
433 	peci_clk->aspeed_peci = priv;
434 
435 	ret = devm_clk_hw_register(dev, &peci_clk->hw);
436 	if (ret)
437 		return ERR_PTR(ret);
438 
439 	return peci_clk->hw.clk;
440 }
441 
442 static void aspeed_peci_property_sanitize(struct device *dev, const char *propname,
443 					  u32 min, u32 max, u32 default_val, u32 *propval)
444 {
445 	u32 val;
446 	int ret;
447 
448 	ret = device_property_read_u32(dev, propname, &val);
449 	if (ret) {
450 		val = default_val;
451 	} else if (val > max || val < min) {
452 		dev_warn(dev, "invalid %s: %u, falling back to: %u\n",
453 			 propname, val, default_val);
454 
455 		val = default_val;
456 	}
457 
458 	*propval = val;
459 }
460 
461 static void aspeed_peci_property_setup(struct aspeed_peci *priv)
462 {
463 	aspeed_peci_property_sanitize(priv->dev, "clock-frequency",
464 				      ASPEED_PECI_CLK_FREQUENCY_MIN, ASPEED_PECI_CLK_FREQUENCY_MAX,
465 				      ASPEED_PECI_CLK_FREQUENCY_DEFAULT, &priv->clk_frequency);
466 	aspeed_peci_property_sanitize(priv->dev, "cmd-timeout-ms",
467 				      1, ASPEED_PECI_CMD_TIMEOUT_MS_MAX,
468 				      ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT, &priv->cmd_timeout_ms);
469 }
470 
471 static const struct peci_controller_ops aspeed_ops = {
472 	.xfer = aspeed_peci_xfer,
473 };
474 
475 static void aspeed_peci_reset_control_release(void *data)
476 {
477 	reset_control_assert(data);
478 }
479 
480 static int devm_aspeed_peci_reset_control_deassert(struct device *dev, struct reset_control *rst)
481 {
482 	int ret;
483 
484 	ret = reset_control_deassert(rst);
485 	if (ret)
486 		return ret;
487 
488 	return devm_add_action_or_reset(dev, aspeed_peci_reset_control_release, rst);
489 }
490 
491 static void aspeed_peci_clk_release(void *data)
492 {
493 	clk_disable_unprepare(data);
494 }
495 
496 static int devm_aspeed_peci_clk_enable(struct device *dev, struct clk *clk)
497 {
498 	int ret;
499 
500 	ret = clk_prepare_enable(clk);
501 	if (ret)
502 		return ret;
503 
504 	return devm_add_action_or_reset(dev, aspeed_peci_clk_release, clk);
505 }
506 
507 static int aspeed_peci_probe(struct platform_device *pdev)
508 {
509 	struct peci_controller *controller;
510 	struct aspeed_peci *priv;
511 	struct clk *ref_clk;
512 	int ret;
513 
514 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
515 	if (!priv)
516 		return -ENOMEM;
517 
518 	priv->dev = &pdev->dev;
519 	dev_set_drvdata(priv->dev, priv);
520 
521 	priv->base = devm_platform_ioremap_resource(pdev, 0);
522 	if (IS_ERR(priv->base))
523 		return PTR_ERR(priv->base);
524 
525 	priv->irq = platform_get_irq(pdev, 0);
526 	if (priv->irq < 0)
527 		return priv->irq;
528 
529 	ret = devm_request_irq(&pdev->dev, priv->irq, aspeed_peci_irq_handler,
530 			       0, "peci-aspeed", priv);
531 	if (ret)
532 		return ret;
533 
534 	init_completion(&priv->xfer_complete);
535 	spin_lock_init(&priv->lock);
536 
537 	priv->rst = devm_reset_control_get(&pdev->dev, NULL);
538 	if (IS_ERR(priv->rst))
539 		return dev_err_probe(priv->dev, PTR_ERR(priv->rst),
540 				     "failed to get reset control\n");
541 
542 	ret = devm_aspeed_peci_reset_control_deassert(priv->dev, priv->rst);
543 	if (ret)
544 		return dev_err_probe(priv->dev, ret, "cannot deassert reset control\n");
545 
546 	aspeed_peci_property_setup(priv);
547 
548 	aspeed_peci_init_regs(priv);
549 
550 	ref_clk = devm_clk_get(priv->dev, NULL);
551 	if (IS_ERR(ref_clk))
552 		return dev_err_probe(priv->dev, PTR_ERR(ref_clk), "failed to get ref clock\n");
553 
554 	priv->clk = devm_aspeed_peci_register_clk_div(priv->dev, ref_clk, priv);
555 	if (IS_ERR(priv->clk))
556 		return dev_err_probe(priv->dev, PTR_ERR(priv->clk), "cannot register clock\n");
557 
558 	ret = clk_set_rate(priv->clk, priv->clk_frequency);
559 	if (ret < 0)
560 		return dev_err_probe(priv->dev, ret, "cannot set clock frequency\n");
561 
562 	ret = devm_aspeed_peci_clk_enable(priv->dev, priv->clk);
563 	if (ret)
564 		return dev_err_probe(priv->dev, ret, "failed to enable clock\n");
565 
566 	aspeed_peci_controller_enable(priv);
567 
568 	controller = devm_peci_controller_add(priv->dev, &aspeed_ops);
569 	if (IS_ERR(controller))
570 		return dev_err_probe(priv->dev, PTR_ERR(controller),
571 				     "failed to add aspeed peci controller\n");
572 
573 	priv->controller = controller;
574 
575 	return 0;
576 }
577 
578 static const struct of_device_id aspeed_peci_of_table[] = {
579 	{ .compatible = "aspeed,ast2400-peci", },
580 	{ .compatible = "aspeed,ast2500-peci", },
581 	{ .compatible = "aspeed,ast2600-peci", },
582 	{ }
583 };
584 MODULE_DEVICE_TABLE(of, aspeed_peci_of_table);
585 
586 static struct platform_driver aspeed_peci_driver = {
587 	.probe  = aspeed_peci_probe,
588 	.driver = {
589 		.name           = "peci-aspeed",
590 		.of_match_table = aspeed_peci_of_table,
591 	},
592 };
593 module_platform_driver(aspeed_peci_driver);
594 
595 MODULE_AUTHOR("Ryan Chen <ryan_chen@aspeedtech.com>");
596 MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
597 MODULE_DESCRIPTION("ASPEED PECI driver");
598 MODULE_LICENSE("GPL");
599 MODULE_IMPORT_NS(PECI);
600