xref: /openbmc/linux/drivers/spi/spi-sprd-adi.c (revision 0c874100)
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_RST			BIT(3)
81 
82 /* Registers definitions for PMIC */
83 #define PMIC_RST_STATUS			0xee8
84 #define PMIC_MODULE_EN			0xc08
85 #define PMIC_CLK_EN			0xc18
86 #define BIT_WDG_EN			BIT(2)
87 
88 /* Definition of PMIC reset status register */
89 #define HWRST_STATUS_RECOVERY		0x20
90 #define HWRST_STATUS_NORMAL		0x40
91 #define HWRST_STATUS_ALARM		0x50
92 #define HWRST_STATUS_SLEEP		0x60
93 #define HWRST_STATUS_FASTBOOT		0x30
94 #define HWRST_STATUS_SPECIAL		0x70
95 #define HWRST_STATUS_PANIC		0x80
96 #define HWRST_STATUS_CFTREBOOT		0x90
97 #define HWRST_STATUS_AUTODLOADER	0xa0
98 #define HWRST_STATUS_IQMODE		0xb0
99 #define HWRST_STATUS_SPRDISK		0xc0
100 
101 /* Use default timeout 50 ms that converts to watchdog values */
102 #define WDG_LOAD_VAL			((50 * 1000) / 32768)
103 #define WDG_LOAD_MASK			GENMASK(15, 0)
104 #define WDG_UNLOCK_KEY			0xe551
105 
106 struct sprd_adi {
107 	struct spi_controller	*ctlr;
108 	struct device		*dev;
109 	void __iomem		*base;
110 	struct hwspinlock	*hwlock;
111 	unsigned long		slave_vbase;
112 	unsigned long		slave_pbase;
113 	struct notifier_block	restart_handler;
114 };
115 
116 static int sprd_adi_check_paddr(struct sprd_adi *sadi, u32 paddr)
117 {
118 	if (paddr < sadi->slave_pbase || paddr >
119 	    (sadi->slave_pbase + ADI_SLAVE_ADDR_SIZE)) {
120 		dev_err(sadi->dev,
121 			"slave physical address is incorrect, addr = 0x%x\n",
122 			paddr);
123 		return -EINVAL;
124 	}
125 
126 	return 0;
127 }
128 
129 static unsigned long sprd_adi_to_vaddr(struct sprd_adi *sadi, u32 paddr)
130 {
131 	return (paddr - sadi->slave_pbase + sadi->slave_vbase);
132 }
133 
134 static int sprd_adi_drain_fifo(struct sprd_adi *sadi)
135 {
136 	u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
137 	u32 sts;
138 
139 	do {
140 		sts = readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS);
141 		if (sts & BIT_FIFO_EMPTY)
142 			break;
143 
144 		cpu_relax();
145 	} while (--timeout);
146 
147 	if (timeout == 0) {
148 		dev_err(sadi->dev, "drain write fifo timeout\n");
149 		return -EBUSY;
150 	}
151 
152 	return 0;
153 }
154 
155 static int sprd_adi_fifo_is_full(struct sprd_adi *sadi)
156 {
157 	return readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS) & BIT_FIFO_FULL;
158 }
159 
160 static int sprd_adi_read(struct sprd_adi *sadi, u32 reg_paddr, u32 *read_val)
161 {
162 	int read_timeout = ADI_READ_TIMEOUT;
163 	unsigned long flags;
164 	u32 val, rd_addr;
165 	int ret;
166 
167 	ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
168 					  ADI_HWSPINLOCK_TIMEOUT,
169 					  &flags);
170 	if (ret) {
171 		dev_err(sadi->dev, "get the hw lock failed\n");
172 		return ret;
173 	}
174 
175 	/*
176 	 * Set the physical register address need to read into RD_CMD register,
177 	 * then ADI controller will start to transfer automatically.
178 	 */
179 	writel_relaxed(reg_paddr, sadi->base + REG_ADI_RD_CMD);
180 
181 	/*
182 	 * Wait read operation complete, the BIT_RD_CMD_BUSY will be set
183 	 * simultaneously when writing read command to register, and the
184 	 * BIT_RD_CMD_BUSY will be cleared after the read operation is
185 	 * completed.
186 	 */
187 	do {
188 		val = readl_relaxed(sadi->base + REG_ADI_RD_DATA);
189 		if (!(val & BIT_RD_CMD_BUSY))
190 			break;
191 
192 		cpu_relax();
193 	} while (--read_timeout);
194 
195 	if (read_timeout == 0) {
196 		dev_err(sadi->dev, "ADI read timeout\n");
197 		ret = -EBUSY;
198 		goto out;
199 	}
200 
201 	/*
202 	 * The return value includes data and read register address, from bit 0
203 	 * to bit 15 are data, and from bit 16 to bit 30 are read register
204 	 * address. Then we can check the returned register address to validate
205 	 * data.
206 	 */
207 	rd_addr = (val & RD_ADDR_MASK ) >> RD_ADDR_SHIFT;
208 
209 	if (rd_addr != (reg_paddr & REG_ADDR_LOW_MASK)) {
210 		dev_err(sadi->dev, "read error, reg addr = 0x%x, val = 0x%x\n",
211 			reg_paddr, val);
212 		ret = -EIO;
213 		goto out;
214 	}
215 
216 	*read_val = val & RD_VALUE_MASK;
217 
218 out:
219 	hwspin_unlock_irqrestore(sadi->hwlock, &flags);
220 	return ret;
221 }
222 
223 static int sprd_adi_write(struct sprd_adi *sadi, u32 reg_paddr, u32 val)
224 {
225 	unsigned long reg = sprd_adi_to_vaddr(sadi, reg_paddr);
226 	u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
227 	unsigned long flags;
228 	int ret;
229 
230 	ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
231 					  ADI_HWSPINLOCK_TIMEOUT,
232 					  &flags);
233 	if (ret) {
234 		dev_err(sadi->dev, "get the hw lock failed\n");
235 		return ret;
236 	}
237 
238 	ret = sprd_adi_drain_fifo(sadi);
239 	if (ret < 0)
240 		goto out;
241 
242 	/*
243 	 * we should wait for write fifo is empty before writing data to PMIC
244 	 * registers.
245 	 */
246 	do {
247 		if (!sprd_adi_fifo_is_full(sadi)) {
248 			writel_relaxed(val, (void __iomem *)reg);
249 			break;
250 		}
251 
252 		cpu_relax();
253 	} while (--timeout);
254 
255 	if (timeout == 0) {
256 		dev_err(sadi->dev, "write fifo is full\n");
257 		ret = -EBUSY;
258 	}
259 
260 out:
261 	hwspin_unlock_irqrestore(sadi->hwlock, &flags);
262 	return ret;
263 }
264 
265 static int sprd_adi_transfer_one(struct spi_controller *ctlr,
266 				 struct spi_device *spi_dev,
267 				 struct spi_transfer *t)
268 {
269 	struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
270 	u32 phy_reg, val;
271 	int ret;
272 
273 	if (t->rx_buf) {
274 		phy_reg = *(u32 *)t->rx_buf + sadi->slave_pbase;
275 
276 		ret = sprd_adi_check_paddr(sadi, phy_reg);
277 		if (ret)
278 			return ret;
279 
280 		ret = sprd_adi_read(sadi, phy_reg, &val);
281 		if (ret)
282 			return ret;
283 
284 		*(u32 *)t->rx_buf = val;
285 	} else if (t->tx_buf) {
286 		u32 *p = (u32 *)t->tx_buf;
287 
288 		/*
289 		 * Get the physical register address need to write and convert
290 		 * the physical address to virtual address. Since we need
291 		 * virtual register address to write.
292 		 */
293 		phy_reg = *p++ + sadi->slave_pbase;
294 		ret = sprd_adi_check_paddr(sadi, phy_reg);
295 		if (ret)
296 			return ret;
297 
298 		val = *p;
299 		ret = sprd_adi_write(sadi, phy_reg, val);
300 		if (ret)
301 			return ret;
302 	} else {
303 		dev_err(sadi->dev, "no buffer for transfer\n");
304 		return -EINVAL;
305 	}
306 
307 	return 0;
308 }
309 
310 static int sprd_adi_restart_handler(struct notifier_block *this,
311 				    unsigned long mode, void *cmd)
312 {
313 	struct sprd_adi *sadi = container_of(this, struct sprd_adi,
314 					     restart_handler);
315 	u32 val, reboot_mode = 0;
316 
317 	if (!cmd)
318 		reboot_mode = HWRST_STATUS_NORMAL;
319 	else if (!strncmp(cmd, "recovery", 8))
320 		reboot_mode = HWRST_STATUS_RECOVERY;
321 	else if (!strncmp(cmd, "alarm", 5))
322 		reboot_mode = HWRST_STATUS_ALARM;
323 	else if (!strncmp(cmd, "fastsleep", 9))
324 		reboot_mode = HWRST_STATUS_SLEEP;
325 	else if (!strncmp(cmd, "bootloader", 10))
326 		reboot_mode = HWRST_STATUS_FASTBOOT;
327 	else if (!strncmp(cmd, "panic", 5))
328 		reboot_mode = HWRST_STATUS_PANIC;
329 	else if (!strncmp(cmd, "special", 7))
330 		reboot_mode = HWRST_STATUS_SPECIAL;
331 	else if (!strncmp(cmd, "cftreboot", 9))
332 		reboot_mode = HWRST_STATUS_CFTREBOOT;
333 	else if (!strncmp(cmd, "autodloader", 11))
334 		reboot_mode = HWRST_STATUS_AUTODLOADER;
335 	else if (!strncmp(cmd, "iqmode", 6))
336 		reboot_mode = HWRST_STATUS_IQMODE;
337 	else if (!strncmp(cmd, "sprdisk", 7))
338 		reboot_mode = HWRST_STATUS_SPRDISK;
339 	else
340 		reboot_mode = HWRST_STATUS_NORMAL;
341 
342 	/* Record the reboot mode */
343 	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_RST_STATUS, &val);
344 	val |= reboot_mode;
345 	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_RST_STATUS, val);
346 
347 	/* Enable the interface clock of the watchdog */
348 	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_MODULE_EN, &val);
349 	val |= BIT_WDG_EN;
350 	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_MODULE_EN, val);
351 
352 	/* Enable the work clock of the watchdog */
353 	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_CLK_EN, &val);
354 	val |= BIT_WDG_EN;
355 	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_CLK_EN, val);
356 
357 	/* Unlock the watchdog */
358 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOCK, WDG_UNLOCK_KEY);
359 
360 	/* Load the watchdog timeout value, 50ms is always enough. */
361 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_LOW,
362 		       WDG_LOAD_VAL & WDG_LOAD_MASK);
363 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_HIGH, 0);
364 
365 	/* Start the watchdog to reset system */
366 	sprd_adi_read(sadi, sadi->slave_pbase + REG_WDG_CTRL, &val);
367 	val |= BIT_WDG_RUN | BIT_WDG_RST;
368 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_CTRL, val);
369 
370 	mdelay(1000);
371 
372 	dev_emerg(sadi->dev, "Unable to restart system\n");
373 	return NOTIFY_DONE;
374 }
375 
376 static void sprd_adi_hw_init(struct sprd_adi *sadi)
377 {
378 	struct device_node *np = sadi->dev->of_node;
379 	int i, size, chn_cnt;
380 	const __be32 *list;
381 	u32 tmp;
382 
383 	/* Address bits select default 12 bits */
384 	writel_relaxed(0, sadi->base + REG_ADI_CTRL0);
385 
386 	/* Set all channels as default priority */
387 	writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIL);
388 	writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIH);
389 
390 	/* Set clock auto gate mode */
391 	tmp = readl_relaxed(sadi->base + REG_ADI_GSSI_CFG0);
392 	tmp &= ~BIT_CLK_ALL_ON;
393 	writel_relaxed(tmp, sadi->base + REG_ADI_GSSI_CFG0);
394 
395 	/* Set hardware channels setting */
396 	list = of_get_property(np, "sprd,hw-channels", &size);
397 	if (!list || !size) {
398 		dev_info(sadi->dev, "no hw channels setting in node\n");
399 		return;
400 	}
401 
402 	chn_cnt = size / 8;
403 	for (i = 0; i < chn_cnt; i++) {
404 		u32 value;
405 		u32 chn_id = be32_to_cpu(*list++);
406 		u32 chn_config = be32_to_cpu(*list++);
407 
408 		/* Channel 0 and 1 are software channels */
409 		if (chn_id < 2)
410 			continue;
411 
412 		writel_relaxed(chn_config, sadi->base +
413 			       REG_ADI_CHN_ADDR(chn_id));
414 
415 		if (chn_id < 32) {
416 			value = readl_relaxed(sadi->base + REG_ADI_CHN_EN);
417 			value |= BIT(chn_id);
418 			writel_relaxed(value, sadi->base + REG_ADI_CHN_EN);
419 		} else if (chn_id < ADI_HW_CHNS) {
420 			value = readl_relaxed(sadi->base + REG_ADI_CHN_EN1);
421 			value |= BIT(chn_id - 32);
422 			writel_relaxed(value, sadi->base + REG_ADI_CHN_EN1);
423 		}
424 	}
425 }
426 
427 static int sprd_adi_probe(struct platform_device *pdev)
428 {
429 	struct device_node *np = pdev->dev.of_node;
430 	struct spi_controller *ctlr;
431 	struct sprd_adi *sadi;
432 	struct resource *res;
433 	u32 num_chipselect;
434 	int ret;
435 
436 	if (!np) {
437 		dev_err(&pdev->dev, "can not find the adi bus node\n");
438 		return -ENODEV;
439 	}
440 
441 	pdev->id = of_alias_get_id(np, "spi");
442 	num_chipselect = of_get_child_count(np);
443 
444 	ctlr = spi_alloc_master(&pdev->dev, sizeof(struct sprd_adi));
445 	if (!ctlr)
446 		return -ENOMEM;
447 
448 	dev_set_drvdata(&pdev->dev, ctlr);
449 	sadi = spi_controller_get_devdata(ctlr);
450 
451 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
452 	sadi->base = devm_ioremap_resource(&pdev->dev, res);
453 	if (IS_ERR(sadi->base)) {
454 		ret = PTR_ERR(sadi->base);
455 		goto put_ctlr;
456 	}
457 
458 	sadi->slave_vbase = (unsigned long)sadi->base + ADI_SLAVE_OFFSET;
459 	sadi->slave_pbase = res->start + ADI_SLAVE_OFFSET;
460 	sadi->ctlr = ctlr;
461 	sadi->dev = &pdev->dev;
462 	ret = of_hwspin_lock_get_id_byname(np, "adi");
463 	if (ret < 0) {
464 		dev_err(&pdev->dev, "can not get the hardware spinlock\n");
465 		goto put_ctlr;
466 	}
467 
468 	sadi->hwlock = devm_hwspin_lock_request_specific(&pdev->dev, ret);
469 	if (!sadi->hwlock) {
470 		ret = -ENXIO;
471 		goto put_ctlr;
472 	}
473 
474 	sprd_adi_hw_init(sadi);
475 
476 	ctlr->dev.of_node = pdev->dev.of_node;
477 	ctlr->bus_num = pdev->id;
478 	ctlr->num_chipselect = num_chipselect;
479 	ctlr->flags = SPI_MASTER_HALF_DUPLEX;
480 	ctlr->bits_per_word_mask = 0;
481 	ctlr->transfer_one = sprd_adi_transfer_one;
482 
483 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
484 	if (ret) {
485 		dev_err(&pdev->dev, "failed to register SPI controller\n");
486 		goto put_ctlr;
487 	}
488 
489 	sadi->restart_handler.notifier_call = sprd_adi_restart_handler;
490 	sadi->restart_handler.priority = 128;
491 	ret = register_restart_handler(&sadi->restart_handler);
492 	if (ret) {
493 		dev_err(&pdev->dev, "can not register restart handler\n");
494 		goto put_ctlr;
495 	}
496 
497 	return 0;
498 
499 put_ctlr:
500 	spi_controller_put(ctlr);
501 	return ret;
502 }
503 
504 static int sprd_adi_remove(struct platform_device *pdev)
505 {
506 	struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
507 	struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
508 
509 	unregister_restart_handler(&sadi->restart_handler);
510 	return 0;
511 }
512 
513 static const struct of_device_id sprd_adi_of_match[] = {
514 	{
515 		.compatible = "sprd,sc9860-adi",
516 	},
517 	{ },
518 };
519 MODULE_DEVICE_TABLE(of, sprd_adi_of_match);
520 
521 static struct platform_driver sprd_adi_driver = {
522 	.driver = {
523 		.name = "sprd-adi",
524 		.of_match_table = sprd_adi_of_match,
525 	},
526 	.probe = sprd_adi_probe,
527 	.remove = sprd_adi_remove,
528 };
529 module_platform_driver(sprd_adi_driver);
530 
531 MODULE_DESCRIPTION("Spreadtrum ADI Controller Driver");
532 MODULE_AUTHOR("Baolin Wang <Baolin.Wang@spreadtrum.com>");
533 MODULE_LICENSE("GPL v2");
534