xref: /openbmc/linux/drivers/spi/spi-sprd-adi.c (revision 2208f39c)
1 /*
2  * Copyright (C) 2017 Spreadtrum Communications Inc.
3  *
4  * SPDX-License-Identifier: GPL-2.0
5  */
6 
7 #include <linux/delay.h>
8 #include <linux/hwspinlock.h>
9 #include <linux/init.h>
10 #include <linux/io.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_device.h>
15 #include <linux/platform_device.h>
16 #include <linux/reboot.h>
17 #include <linux/spi/spi.h>
18 #include <linux/sizes.h>
19 
20 /* Registers definitions for ADI controller */
21 #define REG_ADI_CTRL0			0x4
22 #define REG_ADI_CHN_PRIL		0x8
23 #define REG_ADI_CHN_PRIH		0xc
24 #define REG_ADI_INT_EN			0x10
25 #define REG_ADI_INT_RAW			0x14
26 #define REG_ADI_INT_MASK		0x18
27 #define REG_ADI_INT_CLR			0x1c
28 #define REG_ADI_GSSI_CFG0		0x20
29 #define REG_ADI_GSSI_CFG1		0x24
30 #define REG_ADI_RD_CMD			0x28
31 #define REG_ADI_RD_DATA			0x2c
32 #define REG_ADI_ARM_FIFO_STS		0x30
33 #define REG_ADI_STS			0x34
34 #define REG_ADI_EVT_FIFO_STS		0x38
35 #define REG_ADI_ARM_CMD_STS		0x3c
36 #define REG_ADI_CHN_EN			0x40
37 #define REG_ADI_CHN_ADDR(id)		(0x44 + (id - 2) * 4)
38 #define REG_ADI_CHN_EN1			0x20c
39 
40 /* Bits definitions for register REG_ADI_GSSI_CFG0 */
41 #define BIT_CLK_ALL_ON			BIT(30)
42 
43 /* Bits definitions for register REG_ADI_RD_DATA */
44 #define BIT_RD_CMD_BUSY			BIT(31)
45 #define RD_ADDR_SHIFT			16
46 #define RD_VALUE_MASK			GENMASK(15, 0)
47 #define RD_ADDR_MASK			GENMASK(30, 16)
48 
49 /* Bits definitions for register REG_ADI_ARM_FIFO_STS */
50 #define BIT_FIFO_FULL			BIT(11)
51 #define BIT_FIFO_EMPTY			BIT(10)
52 
53 /*
54  * ADI slave devices include RTC, ADC, regulator, charger, thermal and so on.
55  * The slave devices address offset is always 0x8000 and size is 4K.
56  */
57 #define ADI_SLAVE_ADDR_SIZE		SZ_4K
58 #define ADI_SLAVE_OFFSET		0x8000
59 
60 /* Timeout (ms) for the trylock of hardware spinlocks */
61 #define ADI_HWSPINLOCK_TIMEOUT		5000
62 /*
63  * ADI controller has 50 channels including 2 software channels
64  * and 48 hardware channels.
65  */
66 #define ADI_HW_CHNS			50
67 
68 #define ADI_FIFO_DRAIN_TIMEOUT		1000
69 #define ADI_READ_TIMEOUT		2000
70 #define REG_ADDR_LOW_MASK		GENMASK(11, 0)
71 
72 /* Registers definitions for PMIC watchdog controller */
73 #define REG_WDG_LOAD_LOW		0x80
74 #define REG_WDG_LOAD_HIGH		0x84
75 #define REG_WDG_CTRL			0x88
76 #define REG_WDG_LOCK			0xa0
77 
78 /* Bits definitions for register REG_WDG_CTRL */
79 #define BIT_WDG_RUN			BIT(1)
80 #define BIT_WDG_NEW			BIT(2)
81 #define BIT_WDG_RST			BIT(3)
82 
83 /* Registers definitions for PMIC */
84 #define PMIC_RST_STATUS			0xee8
85 #define PMIC_MODULE_EN			0xc08
86 #define PMIC_CLK_EN			0xc18
87 #define BIT_WDG_EN			BIT(2)
88 
89 /* Definition of PMIC reset status register */
90 #define HWRST_STATUS_SECURITY		0x02
91 #define HWRST_STATUS_RECOVERY		0x20
92 #define HWRST_STATUS_NORMAL		0x40
93 #define HWRST_STATUS_ALARM		0x50
94 #define HWRST_STATUS_SLEEP		0x60
95 #define HWRST_STATUS_FASTBOOT		0x30
96 #define HWRST_STATUS_SPECIAL		0x70
97 #define HWRST_STATUS_PANIC		0x80
98 #define HWRST_STATUS_CFTREBOOT		0x90
99 #define HWRST_STATUS_AUTODLOADER	0xa0
100 #define HWRST_STATUS_IQMODE		0xb0
101 #define HWRST_STATUS_SPRDISK		0xc0
102 #define HWRST_STATUS_FACTORYTEST	0xe0
103 #define HWRST_STATUS_WATCHDOG		0xf0
104 
105 /* Use default timeout 50 ms that converts to watchdog values */
106 #define WDG_LOAD_VAL			((50 * 1000) / 32768)
107 #define WDG_LOAD_MASK			GENMASK(15, 0)
108 #define WDG_UNLOCK_KEY			0xe551
109 
110 struct sprd_adi {
111 	struct spi_controller	*ctlr;
112 	struct device		*dev;
113 	void __iomem		*base;
114 	struct hwspinlock	*hwlock;
115 	unsigned long		slave_vbase;
116 	unsigned long		slave_pbase;
117 	struct notifier_block	restart_handler;
118 };
119 
120 static int sprd_adi_check_paddr(struct sprd_adi *sadi, u32 paddr)
121 {
122 	if (paddr < sadi->slave_pbase || paddr >
123 	    (sadi->slave_pbase + ADI_SLAVE_ADDR_SIZE)) {
124 		dev_err(sadi->dev,
125 			"slave physical address is incorrect, addr = 0x%x\n",
126 			paddr);
127 		return -EINVAL;
128 	}
129 
130 	return 0;
131 }
132 
133 static unsigned long sprd_adi_to_vaddr(struct sprd_adi *sadi, u32 paddr)
134 {
135 	return (paddr - sadi->slave_pbase + sadi->slave_vbase);
136 }
137 
138 static int sprd_adi_drain_fifo(struct sprd_adi *sadi)
139 {
140 	u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
141 	u32 sts;
142 
143 	do {
144 		sts = readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS);
145 		if (sts & BIT_FIFO_EMPTY)
146 			break;
147 
148 		cpu_relax();
149 	} while (--timeout);
150 
151 	if (timeout == 0) {
152 		dev_err(sadi->dev, "drain write fifo timeout\n");
153 		return -EBUSY;
154 	}
155 
156 	return 0;
157 }
158 
159 static int sprd_adi_fifo_is_full(struct sprd_adi *sadi)
160 {
161 	return readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS) & BIT_FIFO_FULL;
162 }
163 
164 static int sprd_adi_read(struct sprd_adi *sadi, u32 reg_paddr, u32 *read_val)
165 {
166 	int read_timeout = ADI_READ_TIMEOUT;
167 	unsigned long flags;
168 	u32 val, rd_addr;
169 	int ret = 0;
170 
171 	if (sadi->hwlock) {
172 		ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
173 						  ADI_HWSPINLOCK_TIMEOUT,
174 						  &flags);
175 		if (ret) {
176 			dev_err(sadi->dev, "get the hw lock failed\n");
177 			return ret;
178 		}
179 	}
180 
181 	/*
182 	 * Set the physical register address need to read into RD_CMD register,
183 	 * then ADI controller will start to transfer automatically.
184 	 */
185 	writel_relaxed(reg_paddr, sadi->base + REG_ADI_RD_CMD);
186 
187 	/*
188 	 * Wait read operation complete, the BIT_RD_CMD_BUSY will be set
189 	 * simultaneously when writing read command to register, and the
190 	 * BIT_RD_CMD_BUSY will be cleared after the read operation is
191 	 * completed.
192 	 */
193 	do {
194 		val = readl_relaxed(sadi->base + REG_ADI_RD_DATA);
195 		if (!(val & BIT_RD_CMD_BUSY))
196 			break;
197 
198 		cpu_relax();
199 	} while (--read_timeout);
200 
201 	if (read_timeout == 0) {
202 		dev_err(sadi->dev, "ADI read timeout\n");
203 		ret = -EBUSY;
204 		goto out;
205 	}
206 
207 	/*
208 	 * The return value includes data and read register address, from bit 0
209 	 * to bit 15 are data, and from bit 16 to bit 30 are read register
210 	 * address. Then we can check the returned register address to validate
211 	 * data.
212 	 */
213 	rd_addr = (val & RD_ADDR_MASK ) >> RD_ADDR_SHIFT;
214 
215 	if (rd_addr != (reg_paddr & REG_ADDR_LOW_MASK)) {
216 		dev_err(sadi->dev, "read error, reg addr = 0x%x, val = 0x%x\n",
217 			reg_paddr, val);
218 		ret = -EIO;
219 		goto out;
220 	}
221 
222 	*read_val = val & RD_VALUE_MASK;
223 
224 out:
225 	if (sadi->hwlock)
226 		hwspin_unlock_irqrestore(sadi->hwlock, &flags);
227 	return ret;
228 }
229 
230 static int sprd_adi_write(struct sprd_adi *sadi, u32 reg_paddr, u32 val)
231 {
232 	unsigned long reg = sprd_adi_to_vaddr(sadi, reg_paddr);
233 	u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
234 	unsigned long flags;
235 	int ret;
236 
237 	if (sadi->hwlock) {
238 		ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
239 						  ADI_HWSPINLOCK_TIMEOUT,
240 						  &flags);
241 		if (ret) {
242 			dev_err(sadi->dev, "get the hw lock failed\n");
243 			return ret;
244 		}
245 	}
246 
247 	ret = sprd_adi_drain_fifo(sadi);
248 	if (ret < 0)
249 		goto out;
250 
251 	/*
252 	 * we should wait for write fifo is empty before writing data to PMIC
253 	 * registers.
254 	 */
255 	do {
256 		if (!sprd_adi_fifo_is_full(sadi)) {
257 			writel_relaxed(val, (void __iomem *)reg);
258 			break;
259 		}
260 
261 		cpu_relax();
262 	} while (--timeout);
263 
264 	if (timeout == 0) {
265 		dev_err(sadi->dev, "write fifo is full\n");
266 		ret = -EBUSY;
267 	}
268 
269 out:
270 	if (sadi->hwlock)
271 		hwspin_unlock_irqrestore(sadi->hwlock, &flags);
272 	return ret;
273 }
274 
275 static int sprd_adi_transfer_one(struct spi_controller *ctlr,
276 				 struct spi_device *spi_dev,
277 				 struct spi_transfer *t)
278 {
279 	struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
280 	u32 phy_reg, val;
281 	int ret;
282 
283 	if (t->rx_buf) {
284 		phy_reg = *(u32 *)t->rx_buf + sadi->slave_pbase;
285 
286 		ret = sprd_adi_check_paddr(sadi, phy_reg);
287 		if (ret)
288 			return ret;
289 
290 		ret = sprd_adi_read(sadi, phy_reg, &val);
291 		if (ret)
292 			return ret;
293 
294 		*(u32 *)t->rx_buf = val;
295 	} else if (t->tx_buf) {
296 		u32 *p = (u32 *)t->tx_buf;
297 
298 		/*
299 		 * Get the physical register address need to write and convert
300 		 * the physical address to virtual address. Since we need
301 		 * virtual register address to write.
302 		 */
303 		phy_reg = *p++ + sadi->slave_pbase;
304 		ret = sprd_adi_check_paddr(sadi, phy_reg);
305 		if (ret)
306 			return ret;
307 
308 		val = *p;
309 		ret = sprd_adi_write(sadi, phy_reg, val);
310 		if (ret)
311 			return ret;
312 	} else {
313 		dev_err(sadi->dev, "no buffer for transfer\n");
314 		return -EINVAL;
315 	}
316 
317 	return 0;
318 }
319 
320 static void sprd_adi_set_wdt_rst_mode(struct sprd_adi *sadi)
321 {
322 #if IS_ENABLED(CONFIG_SPRD_WATCHDOG)
323 	u32 val;
324 
325 	/* Set default watchdog reboot mode */
326 	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_RST_STATUS, &val);
327 	val |= HWRST_STATUS_WATCHDOG;
328 	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_RST_STATUS, val);
329 #endif
330 }
331 
332 static int sprd_adi_restart_handler(struct notifier_block *this,
333 				    unsigned long mode, void *cmd)
334 {
335 	struct sprd_adi *sadi = container_of(this, struct sprd_adi,
336 					     restart_handler);
337 	u32 val, reboot_mode = 0;
338 
339 	if (!cmd)
340 		reboot_mode = HWRST_STATUS_NORMAL;
341 	else if (!strncmp(cmd, "recovery", 8))
342 		reboot_mode = HWRST_STATUS_RECOVERY;
343 	else if (!strncmp(cmd, "alarm", 5))
344 		reboot_mode = HWRST_STATUS_ALARM;
345 	else if (!strncmp(cmd, "fastsleep", 9))
346 		reboot_mode = HWRST_STATUS_SLEEP;
347 	else if (!strncmp(cmd, "bootloader", 10))
348 		reboot_mode = HWRST_STATUS_FASTBOOT;
349 	else if (!strncmp(cmd, "panic", 5))
350 		reboot_mode = HWRST_STATUS_PANIC;
351 	else if (!strncmp(cmd, "special", 7))
352 		reboot_mode = HWRST_STATUS_SPECIAL;
353 	else if (!strncmp(cmd, "cftreboot", 9))
354 		reboot_mode = HWRST_STATUS_CFTREBOOT;
355 	else if (!strncmp(cmd, "autodloader", 11))
356 		reboot_mode = HWRST_STATUS_AUTODLOADER;
357 	else if (!strncmp(cmd, "iqmode", 6))
358 		reboot_mode = HWRST_STATUS_IQMODE;
359 	else if (!strncmp(cmd, "sprdisk", 7))
360 		reboot_mode = HWRST_STATUS_SPRDISK;
361 	else if (!strncmp(cmd, "tospanic", 8))
362 		reboot_mode = HWRST_STATUS_SECURITY;
363 	else if (!strncmp(cmd, "factorytest", 11))
364 		reboot_mode = HWRST_STATUS_FACTORYTEST;
365 	else
366 		reboot_mode = HWRST_STATUS_NORMAL;
367 
368 	/* Record the reboot mode */
369 	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_RST_STATUS, &val);
370 	val &= ~HWRST_STATUS_WATCHDOG;
371 	val |= reboot_mode;
372 	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_RST_STATUS, val);
373 
374 	/* Enable the interface clock of the watchdog */
375 	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_MODULE_EN, &val);
376 	val |= BIT_WDG_EN;
377 	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_MODULE_EN, val);
378 
379 	/* Enable the work clock of the watchdog */
380 	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_CLK_EN, &val);
381 	val |= BIT_WDG_EN;
382 	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_CLK_EN, val);
383 
384 	/* Unlock the watchdog */
385 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOCK, WDG_UNLOCK_KEY);
386 
387 	sprd_adi_read(sadi, sadi->slave_pbase + REG_WDG_CTRL, &val);
388 	val |= BIT_WDG_NEW;
389 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_CTRL, val);
390 
391 	/* Load the watchdog timeout value, 50ms is always enough. */
392 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_HIGH, 0);
393 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_LOW,
394 		       WDG_LOAD_VAL & WDG_LOAD_MASK);
395 
396 	/* Start the watchdog to reset system */
397 	sprd_adi_read(sadi, sadi->slave_pbase + REG_WDG_CTRL, &val);
398 	val |= BIT_WDG_RUN | BIT_WDG_RST;
399 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_CTRL, val);
400 
401 	/* Lock the watchdog */
402 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOCK, ~WDG_UNLOCK_KEY);
403 
404 	mdelay(1000);
405 
406 	dev_emerg(sadi->dev, "Unable to restart system\n");
407 	return NOTIFY_DONE;
408 }
409 
410 static void sprd_adi_hw_init(struct sprd_adi *sadi)
411 {
412 	struct device_node *np = sadi->dev->of_node;
413 	int i, size, chn_cnt;
414 	const __be32 *list;
415 	u32 tmp;
416 
417 	/* Set all channels as default priority */
418 	writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIL);
419 	writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIH);
420 
421 	/* Set clock auto gate mode */
422 	tmp = readl_relaxed(sadi->base + REG_ADI_GSSI_CFG0);
423 	tmp &= ~BIT_CLK_ALL_ON;
424 	writel_relaxed(tmp, sadi->base + REG_ADI_GSSI_CFG0);
425 
426 	/* Set hardware channels setting */
427 	list = of_get_property(np, "sprd,hw-channels", &size);
428 	if (!list || !size) {
429 		dev_info(sadi->dev, "no hw channels setting in node\n");
430 		return;
431 	}
432 
433 	chn_cnt = size / 8;
434 	for (i = 0; i < chn_cnt; i++) {
435 		u32 value;
436 		u32 chn_id = be32_to_cpu(*list++);
437 		u32 chn_config = be32_to_cpu(*list++);
438 
439 		/* Channel 0 and 1 are software channels */
440 		if (chn_id < 2)
441 			continue;
442 
443 		writel_relaxed(chn_config, sadi->base +
444 			       REG_ADI_CHN_ADDR(chn_id));
445 
446 		if (chn_id < 32) {
447 			value = readl_relaxed(sadi->base + REG_ADI_CHN_EN);
448 			value |= BIT(chn_id);
449 			writel_relaxed(value, sadi->base + REG_ADI_CHN_EN);
450 		} else if (chn_id < ADI_HW_CHNS) {
451 			value = readl_relaxed(sadi->base + REG_ADI_CHN_EN1);
452 			value |= BIT(chn_id - 32);
453 			writel_relaxed(value, sadi->base + REG_ADI_CHN_EN1);
454 		}
455 	}
456 }
457 
458 static int sprd_adi_probe(struct platform_device *pdev)
459 {
460 	struct device_node *np = pdev->dev.of_node;
461 	struct spi_controller *ctlr;
462 	struct sprd_adi *sadi;
463 	struct resource *res;
464 	u32 num_chipselect;
465 	int ret;
466 
467 	if (!np) {
468 		dev_err(&pdev->dev, "can not find the adi bus node\n");
469 		return -ENODEV;
470 	}
471 
472 	pdev->id = of_alias_get_id(np, "spi");
473 	num_chipselect = of_get_child_count(np);
474 
475 	ctlr = spi_alloc_master(&pdev->dev, sizeof(struct sprd_adi));
476 	if (!ctlr)
477 		return -ENOMEM;
478 
479 	dev_set_drvdata(&pdev->dev, ctlr);
480 	sadi = spi_controller_get_devdata(ctlr);
481 
482 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
483 	sadi->base = devm_ioremap_resource(&pdev->dev, res);
484 	if (IS_ERR(sadi->base)) {
485 		ret = PTR_ERR(sadi->base);
486 		goto put_ctlr;
487 	}
488 
489 	sadi->slave_vbase = (unsigned long)sadi->base + ADI_SLAVE_OFFSET;
490 	sadi->slave_pbase = res->start + ADI_SLAVE_OFFSET;
491 	sadi->ctlr = ctlr;
492 	sadi->dev = &pdev->dev;
493 	ret = of_hwspin_lock_get_id(np, 0);
494 	if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
495 		sadi->hwlock =
496 			devm_hwspin_lock_request_specific(&pdev->dev, ret);
497 		if (!sadi->hwlock) {
498 			ret = -ENXIO;
499 			goto put_ctlr;
500 		}
501 	} else {
502 		switch (ret) {
503 		case -ENOENT:
504 			dev_info(&pdev->dev, "no hardware spinlock supplied\n");
505 			break;
506 		default:
507 			dev_err_probe(&pdev->dev, ret, "failed to find hwlock id\n");
508 			goto put_ctlr;
509 		}
510 	}
511 
512 	sprd_adi_hw_init(sadi);
513 	sprd_adi_set_wdt_rst_mode(sadi);
514 
515 	ctlr->dev.of_node = pdev->dev.of_node;
516 	ctlr->bus_num = pdev->id;
517 	ctlr->num_chipselect = num_chipselect;
518 	ctlr->flags = SPI_MASTER_HALF_DUPLEX;
519 	ctlr->bits_per_word_mask = 0;
520 	ctlr->transfer_one = sprd_adi_transfer_one;
521 
522 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
523 	if (ret) {
524 		dev_err(&pdev->dev, "failed to register SPI controller\n");
525 		goto put_ctlr;
526 	}
527 
528 	sadi->restart_handler.notifier_call = sprd_adi_restart_handler;
529 	sadi->restart_handler.priority = 128;
530 	ret = register_restart_handler(&sadi->restart_handler);
531 	if (ret) {
532 		dev_err(&pdev->dev, "can not register restart handler\n");
533 		goto put_ctlr;
534 	}
535 
536 	return 0;
537 
538 put_ctlr:
539 	spi_controller_put(ctlr);
540 	return ret;
541 }
542 
543 static int sprd_adi_remove(struct platform_device *pdev)
544 {
545 	struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
546 	struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
547 
548 	unregister_restart_handler(&sadi->restart_handler);
549 	return 0;
550 }
551 
552 static const struct of_device_id sprd_adi_of_match[] = {
553 	{
554 		.compatible = "sprd,sc9860-adi",
555 	},
556 	{ },
557 };
558 MODULE_DEVICE_TABLE(of, sprd_adi_of_match);
559 
560 static struct platform_driver sprd_adi_driver = {
561 	.driver = {
562 		.name = "sprd-adi",
563 		.of_match_table = sprd_adi_of_match,
564 	},
565 	.probe = sprd_adi_probe,
566 	.remove = sprd_adi_remove,
567 };
568 module_platform_driver(sprd_adi_driver);
569 
570 MODULE_DESCRIPTION("Spreadtrum ADI Controller Driver");
571 MODULE_AUTHOR("Baolin Wang <Baolin.Wang@spreadtrum.com>");
572 MODULE_LICENSE("GPL v2");
573