1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright 2022 Gateworks Corporation
4 */
5
6#include <command.h>
7#include <gsc.h>
8#include <i2c.h>
9#include <rtc.h>
10#include <asm/unaligned.h>
11#include <linux/delay.h>
12#include <dm/device.h>
13#include <dm/device-internal.h>
14#include <dm/ofnode.h>
15#include <dm/read.h>
16
17#define GSC_BUSNO	0
18#define GSC_SC_ADDR	0x20
19#define GSC_HWMON_ADDR	0x29
20#define GSC_RTC_ADDR	0x68
21
22/* System Controller registers */
23enum {
24	GSC_SC_CTRL0		= 0,
25	GSC_SC_CTRL1		= 1,
26	GSC_SC_TIME		= 2,
27	GSC_SC_TIME_ADD		= 6,
28	GSC_SC_STATUS		= 10,
29	GSC_SC_FWCRC		= 12,
30	GSC_SC_FWVER		= 14,
31	GSC_SC_WP		= 15,
32	GSC_SC_RST_CAUSE	= 16,
33	GSC_SC_THERM_PROTECT	= 19,
34};
35
36/* System Controller Control1 bits */
37enum {
38	GSC_SC_CTRL1_SLEEP_EN		= 0, /* 1 = enable sleep */
39	GSC_SC_CTRL1_SLEEP_ACTIVATE	= 1, /* 1 = activate sleep */
40	GSC_SC_CTRL1_SLEEP_ADD		= 2, /* 1 = latch and add sleep time */
41	GSC_SC_CTRL1_SLEEP_NOWAKEPB	= 3, /* 1 = do not wake on sleep on button press */
42	GSC_SC_CTRL1_WDTIME		= 4, /* 1 = 60s timeout, 0 = 30s timeout */
43	GSC_SC_CTRL1_WDEN		= 5, /* 1 = enable, 0 = disable */
44	GSC_SC_CTRL1_BOOT_CHK		= 6, /* 1 = enable alt boot check */
45	GSC_SC_CTRL1_WDDIS		= 7, /* 1 = disable boot watchdog */
46};
47
48/* System Controller Interrupt bits */
49enum {
50	GSC_SC_IRQ_PB		= 0, /* Pushbutton switch */
51	GSC_SC_IRQ_SECURE	= 1, /* Secure Key erase operation complete */
52	GSC_SC_IRQ_EEPROM_WP	= 2, /* EEPROM write violation */
53	GSC_SC_IRQ_GPIO		= 4, /* GPIO change */
54	GSC_SC_IRQ_TAMPER	= 5, /* Tamper detect */
55	GSC_SC_IRQ_WATCHDOG	= 6, /* Watchdog trip */
56	GSC_SC_IRQ_PBLONG	= 7, /* Pushbutton long hold */
57};
58
59/* System Controller WP bits */
60enum {
61	GSC_SC_WP_ALL		= 0, /* Write Protect All EEPROM regions */
62	GSC_SC_WP_BOARDINFO	= 1, /* Write Protect Board Info region */
63};
64
65/* System Controller Reset Cause */
66enum {
67	GSC_SC_RST_CAUSE_VIN		= 0,
68	GSC_SC_RST_CAUSE_PB		= 1,
69	GSC_SC_RST_CAUSE_WDT		= 2,
70	GSC_SC_RST_CAUSE_CPU		= 3,
71	GSC_SC_RST_CAUSE_TEMP_LOCAL	= 4,
72	GSC_SC_RST_CAUSE_TEMP_REMOTE	= 5,
73	GSC_SC_RST_CAUSE_SLEEP		= 6,
74	GSC_SC_RST_CAUSE_BOOT_WDT	= 7,
75	GSC_SC_RST_CAUSE_BOOT_WDT_MAN	= 8,
76	GSC_SC_RST_CAUSE_SOFT_PWR	= 9,
77	GSC_SC_RST_CAUSE_MAX		= 10,
78};
79
80#if CONFIG_IS_ENABLED(DM_I2C)
81
82struct gsc_priv {
83	int gscver;
84	int fwver;
85	int fwcrc;
86	struct udevice *hwmon;
87	struct udevice *rtc;
88};
89
90/*
91 * GSCv2 will fail to ACK an I2C transaction if it is busy, which can occur
92 * during its 1HZ timer tick while reading ADC's. When this does occur,
93 * it will never be busy longer than 2 back-to-back transfers so retry 3 times.
94 */
95static int gsc_i2c_read(struct udevice *dev, uint addr, u8 *buf, int len)
96{
97	struct gsc_priv *priv = dev_get_priv(dev);
98	int retry = (priv->gscver == 3) ? 1 : 3;
99	int n = 0;
100	int ret;
101
102	while (n++ < retry) {
103		ret = dm_i2c_read(dev, addr, buf, len);
104		if (!ret)
105			break;
106		if (ret != -EREMOTEIO)
107			break;
108		mdelay(10);
109	}
110	return ret;
111}
112
113static int gsc_i2c_write(struct udevice *dev, uint addr, const u8 *buf, int len)
114{
115	struct gsc_priv *priv = dev_get_priv(dev);
116	int retry = (priv->gscver == 3) ? 1 : 3;
117	int n = 0;
118	int ret;
119
120	while (n++ < retry) {
121		ret = dm_i2c_write(dev, addr, buf, len);
122		if (!ret)
123			break;
124		if (ret != -EREMOTEIO)
125			break;
126		mdelay(10);
127	}
128	return ret;
129}
130
131static struct udevice *gsc_get_dev(int busno, int slave)
132{
133	struct udevice *dev, *bus;
134	int ret;
135
136	ret = uclass_get_device_by_seq(UCLASS_I2C, busno, &bus);
137	if (ret)
138		return NULL;
139	ret = dm_i2c_probe(bus, slave, 0, &dev);
140	if (ret)
141		return NULL;
142
143	return dev;
144}
145
146static int gsc_thermal_get_info(struct udevice *dev, u8 *outreg, int *tmax, bool *enable)
147{
148	struct gsc_priv *priv = dev_get_priv(dev);
149	int ret;
150	u8 reg;
151
152	if (priv->gscver > 2 && priv->fwver > 52) {
153		ret = gsc_i2c_read(dev, GSC_SC_THERM_PROTECT, &reg, 1);
154		if (!ret) {
155			if (outreg)
156				*outreg = reg;
157			if (tmax) {
158				*tmax = ((reg & 0xf8) >> 3) * 2;
159				if (*tmax)
160					*tmax += 70;
161				else
162					*tmax = 120;
163			}
164			if (enable)
165				*enable = reg & 1;
166		}
167	} else {
168		ret = -ENODEV;
169	}
170
171	return ret;
172}
173
174static int gsc_thermal_get_temp(struct udevice *dev)
175{
176	struct gsc_priv *priv = dev_get_priv(dev);
177	u32 reg, mode, val;
178	const char *label;
179	ofnode node;
180	u8 buf[2];
181
182	ofnode_for_each_subnode(node, dev_read_subnode(dev, "adc")) {
183		if (ofnode_read_u32(node, "reg", &reg))
184			reg = -1;
185		if (ofnode_read_u32(node, "gw,mode", &mode))
186			mode = -1;
187		label = ofnode_read_string(node, "label");
188
189		if ((reg == -1) || (mode == -1) || !label)
190			continue;
191
192		if (mode != 0 || strcmp(label, "temp"))
193			continue;
194
195		memset(buf, 0, sizeof(buf));
196		if (!gsc_i2c_read(priv->hwmon, reg, buf, sizeof(buf))) {
197			val = buf[0] | buf[1] << 8;
198			if (val > 0x8000)
199				val -= 0xffff;
200			return val;
201		}
202	}
203
204	return 0;
205}
206
207static void gsc_thermal_info(struct udevice *dev)
208{
209	struct gsc_priv *priv = dev_get_priv(dev);
210
211	switch (priv->gscver) {
212	case 2:
213		printf("board_temp:%dC ", gsc_thermal_get_temp(dev) / 10);
214		break;
215	case 3:
216		if (priv->fwver > 52) {
217			bool enabled;
218			int tmax;
219
220			if (!gsc_thermal_get_info(dev, NULL, &tmax, &enabled)) {
221				puts("Thermal protection:");
222				if (enabled)
223					printf("enabled at %dC ", tmax);
224				else
225					puts("disabled ");
226			}
227		}
228		break;
229	}
230}
231
232static void gsc_reset_info(struct udevice *dev)
233{
234	struct gsc_priv *priv = dev_get_priv(dev);
235	static const char * const names[] = {
236		"VIN",
237		"PB",
238		"WDT",
239		"CPU",
240		"TEMP_L",
241		"TEMP_R",
242		"SLEEP",
243		"BOOT_WDT1",
244		"BOOT_WDT2",
245		"SOFT_PWR",
246	};
247	u8 reg;
248
249	/* reset cause */
250	switch (priv->gscver) {
251	case 2:
252		if (!gsc_i2c_read(dev, GSC_SC_STATUS, &reg, 1)) {
253			if (reg & BIT(GSC_SC_IRQ_WATCHDOG)) {
254				puts("RST:WDT");
255				reg &= ~BIT(GSC_SC_IRQ_WATCHDOG);
256				gsc_i2c_write(dev, GSC_SC_STATUS, &reg, 1);
257			} else {
258				puts("RST:VIN");
259			}
260			printf(" WDT:%sabled ",
261			       (reg & BIT(GSC_SC_CTRL1_WDEN)) ? "en" : "dis");
262		}
263		break;
264	case 3:
265		if (priv->fwver > 52 &&
266		    !gsc_i2c_read(dev, GSC_SC_RST_CAUSE, &reg, 1)) {
267			puts("RST:");
268			if (reg < ARRAY_SIZE(names))
269				printf("%s ", names[reg]);
270			else
271				printf("0x%02x ", reg);
272		}
273		break;
274	}
275}
276
277/* display hardware monitor ADC channels */
278static int gsc_hwmon(struct udevice *dev)
279{
280	struct gsc_priv *priv = dev_get_priv(dev);
281	u32 reg, mode, val, offset;
282	const char *label;
283	ofnode node;
284	u8 buf[2];
285	u32 r[2];
286	int ret;
287
288	/* iterate over hwmon nodes */
289	ofnode_for_each_subnode(node, dev_read_subnode(dev, "adc")) {
290		if (ofnode_read_u32(node, "reg", &reg))
291			reg = -1;
292		if (ofnode_read_u32(node, "gw,mode", &mode))
293			mode = -1;
294		label = ofnode_read_string(node, "label");
295		if ((reg == -1) || (mode == -1) || !label)
296			continue;
297
298		memset(buf, 0, sizeof(buf));
299		ret = gsc_i2c_read(priv->hwmon, reg, buf, sizeof(buf));
300		if (ret) {
301			printf("i2c error: %d\n", ret);
302			continue;
303		}
304		val = buf[0] | buf[1] << 8;
305
306		switch (mode) {
307		case 0: /* temperature (C*10) */
308			if (val > 0x8000)
309				val -= 0xffff;
310			printf("%-8s: %d.%ldC\n", label, val / 10, abs(val % 10));
311			break;
312		case 1: /* prescaled voltage */
313			if (val != 0xffff)
314				printf("%-8s: %d.%03dV\n", label, val / 1000, val % 1000);
315			break;
316		case 2: /* scaled based on ref volt and resolution */
317			val *= 2500;
318			val /= 1 << 12;
319
320			/* apply pre-scaler voltage divider */
321			if (!ofnode_read_u32_index(node, "gw,voltage-divider-ohms", 0, &r[0]) &&
322			    !ofnode_read_u32_index(node, "gw,voltage-divider-ohms", 1, &r[1]) &&
323			    r[0] && r[1]) {
324				val *= (r[0] + r[1]);
325				val /= r[1];
326			}
327
328			/* adjust by offset */
329			val += (offset / 1000);
330
331			printf("%-8s: %d.%03dV\n", label, val / 1000, val % 1000);
332			break;
333		}
334	}
335
336	return 0;
337}
338
339static int gsc_banner(struct udevice *dev)
340{
341	struct gsc_priv *priv = dev_get_priv(dev);
342
343	/* banner */
344	printf("GSCv%d   : v%d 0x%04x ", priv->gscver, priv->fwver, priv->fwcrc);
345	gsc_reset_info(dev);
346	gsc_thermal_info(dev);
347	puts("\n");
348
349	/* Display RTC */
350	if (priv->rtc) {
351		u8 buf[4];
352		time_t timestamp;
353		struct rtc_time tm;
354
355		if (!gsc_i2c_read(priv->rtc, 0, buf, 4)) {
356			timestamp = get_unaligned_le32(buf);
357			rtc_to_tm(timestamp, &tm);
358			printf("RTC     : %4d-%02d-%02d  %2d:%02d:%02d UTC\n",
359			       tm.tm_year, tm.tm_mon, tm.tm_mday,
360			       tm.tm_hour, tm.tm_min, tm.tm_sec);
361		}
362	}
363
364	return 0;
365}
366
367static int gsc_probe(struct udevice *dev)
368{
369	struct gsc_priv *priv = dev_get_priv(dev);
370	u8 buf[32];
371	int ret;
372
373	ret = gsc_i2c_read(dev, 0, buf, sizeof(buf));
374	if (ret)
375		return ret;
376
377	/*
378	 * GSC chip version:
379	 *   GSCv2 has 16 registers (which overlap)
380	 *   GSCv3 has 32 registers
381	 */
382	priv->gscver = memcmp(buf, buf + 16, 16) ? 3 : 2;
383	priv->fwver = buf[GSC_SC_FWVER];
384	priv->fwcrc = buf[GSC_SC_FWCRC] | buf[GSC_SC_FWCRC + 1] << 8;
385	priv->hwmon = gsc_get_dev(GSC_BUSNO, GSC_HWMON_ADDR);
386	if (priv->hwmon)
387		dev_set_priv(priv->hwmon, priv);
388	priv->rtc = gsc_get_dev(GSC_BUSNO, GSC_RTC_ADDR);
389	if (priv->rtc)
390		dev_set_priv(priv->rtc, priv);
391
392#ifdef CONFIG_SPL_BUILD
393	gsc_banner(dev);
394#endif
395
396	return 0;
397};
398
399static const struct udevice_id gsc_ids[] = {
400	{ .compatible = "gw,gsc", },
401	{ }
402};
403
404U_BOOT_DRIVER(gsc) = {
405	.name = "gsc",
406	.id = UCLASS_MISC,
407	.of_match = gsc_ids,
408	.probe = gsc_probe,
409	.priv_auto      = sizeof(struct gsc_priv),
410	.flags = DM_FLAG_PRE_RELOC,
411};
412
413static int gsc_sleep(struct udevice *dev, unsigned long secs)
414{
415	u8 regs[4];
416	int ret;
417
418	printf("GSC Sleeping for %ld seconds\n", secs);
419	put_unaligned_le32(secs, regs);
420	ret = gsc_i2c_write(dev, GSC_SC_TIME_ADD, regs, sizeof(regs));
421	if (ret)
422		goto err;
423	ret = gsc_i2c_read(dev, GSC_SC_CTRL1, regs, 1);
424	if (ret)
425		goto err;
426	regs[0] |= BIT(GSC_SC_CTRL1_SLEEP_ADD);
427	ret = gsc_i2c_write(dev, GSC_SC_CTRL1, regs, 1);
428	if (ret)
429		goto err;
430	regs[0] &= ~BIT(GSC_SC_CTRL1_SLEEP_ADD);
431	regs[0] |= BIT(GSC_SC_CTRL1_SLEEP_EN) | BIT(GSC_SC_CTRL1_SLEEP_ACTIVATE);
432	ret = gsc_i2c_write(dev, GSC_SC_CTRL1, regs, 1);
433	if (ret)
434		goto err;
435
436	return 0;
437
438err:
439	printf("i2c error: %d\n", ret);
440	return ret;
441}
442
443static int gsc_wd_disable(struct udevice *dev)
444{
445	int ret;
446	u8 reg;
447
448	ret = gsc_i2c_read(dev, GSC_SC_CTRL1, &reg, 1);
449	if (ret)
450		goto err;
451	reg |= BIT(GSC_SC_CTRL1_WDDIS);
452	reg &= ~BIT(GSC_SC_CTRL1_BOOT_CHK);
453	ret = gsc_i2c_write(dev, GSC_SC_CTRL1, &reg, 1);
454	if (ret)
455		goto err;
456	puts("GSC     : boot watchdog disabled\n");
457
458	return 0;
459
460err:
461	puts("i2c error");
462	return ret;
463}
464
465static int gsc_thermal(struct udevice *dev, const char *cmd, const char *val)
466{
467	struct gsc_priv *priv = dev_get_priv(dev);
468	int ret, tmax;
469	bool enabled;
470	u8 reg;
471
472	if (priv->gscver < 3 || priv->fwver < 53)
473		return -EINVAL;
474	ret = gsc_thermal_get_info(dev, &reg, &tmax, &enabled);
475	if (ret)
476		return ret;
477	if (cmd && !strcmp(cmd, "enable")) {
478		if (val && *val) {
479			tmax = clamp((int)simple_strtoul(val, NULL, 0), 72, 122);
480			reg &= ~0xf8;
481			reg |= ((tmax - 70) / 2) << 3;
482		}
483		reg |= BIT(0);
484		gsc_i2c_write(dev, GSC_SC_THERM_PROTECT, &reg, 1);
485	} else if (cmd && !strcmp(cmd, "disable")) {
486		reg &= ~BIT(0);
487		gsc_i2c_write(dev, GSC_SC_THERM_PROTECT, &reg, 1);
488	} else if (cmd) {
489		return -EINVAL;
490	}
491
492	/* show status */
493	gsc_thermal_info(dev);
494	puts("\n");
495
496	return 0;
497}
498
499/* override in board files to display additional board EEPROM info */
500__weak void board_gsc_info(void)
501{
502}
503
504static void gsc_info(struct udevice *dev)
505{
506	gsc_banner(dev);
507	board_gsc_info();
508}
509
510static int do_gsc(struct cmd_tbl *cmdtp, int flag, int argc, char * const argv[])
511{
512	struct udevice *dev;
513	int ret;
514
515	/* get/probe driver */
516	ret = uclass_get_device_by_driver(UCLASS_MISC, DM_DRIVER_GET(gsc), &dev);
517	if (ret)
518		return CMD_RET_USAGE;
519	if (argc < 2) {
520		gsc_info(dev);
521		return CMD_RET_SUCCESS;
522	} else if (strcasecmp(argv[1], "sleep") == 0) {
523		if (argc < 3)
524			return CMD_RET_USAGE;
525		if (!gsc_sleep(dev, dectoul(argv[2], NULL)))
526			return CMD_RET_SUCCESS;
527	} else if (strcasecmp(argv[1], "hwmon") == 0) {
528		if (!gsc_hwmon(dev))
529			return CMD_RET_SUCCESS;
530	} else if (strcasecmp(argv[1], "wd-disable") == 0) {
531		if (!gsc_wd_disable(dev))
532			return CMD_RET_SUCCESS;
533	} else if (strcasecmp(argv[1], "thermal") == 0) {
534		const char *cmd, *val;
535
536		cmd = cmd_arg2(argc, argv);
537		val = cmd_arg3(argc, argv);
538		if (!gsc_thermal(dev, cmd, val))
539			return CMD_RET_SUCCESS;
540	}
541
542	return CMD_RET_USAGE;
543}
544
545U_BOOT_CMD(gsc, 4, 1, do_gsc, "Gateworks System Controller",
546	   "[sleep <secs>]|[hwmon]|[wd-disable][thermal [disable|enable [temp]]]\n");
547
548/* disable boot watchdog - useful for an SPL that wants to use falcon mode */
549int gsc_boot_wd_disable(void)
550{
551	struct udevice *dev;
552	int ret;
553
554	/* get/probe driver */
555	ret = uclass_get_device_by_driver(UCLASS_MISC, DM_DRIVER_GET(gsc), &dev);
556	if (!ret)
557		ret = gsc_wd_disable(dev);
558
559	return ret;
560}
561
562# else
563
564/*
565 * GSCv2 will fail to ACK an I2C transaction if it is busy, which can occur
566 * during its 1HZ timer tick while reading ADC's. When this does occur,
567 * it will never be busy longer than 2 back-to-back transfers so retry 3 times.
568 */
569static int gsc_i2c_read(uint chip, uint addr, u8 *buf, int len)
570{
571	int retry = 3;
572	int n = 0;
573	int ret;
574
575	while (n++ < retry) {
576		ret = i2c_read(chip, addr, 1, buf, len);
577		if (!ret)
578			break;
579		if (ret != -EREMOTEIO)
580			break;
581printf("%s 0x%02x retry %d\n", __func__, addr, n);
582		mdelay(10);
583	}
584	return ret;
585}
586
587static int gsc_i2c_write(uint chip, uint addr, u8 *buf, int len)
588{
589	int retry = 3;
590	int n = 0;
591	int ret;
592
593	while (n++ < retry) {
594		ret = i2c_write(chip, addr, 1, buf, len);
595		if (!ret)
596			break;
597		if (ret != -EREMOTEIO)
598			break;
599printf("%s 0x%02x retry %d\n", __func__, addr, n);
600		mdelay(10);
601	}
602	return ret;
603}
604
605/* disable boot watchdog - useful for an SPL that wants to use falcon mode */
606int gsc_boot_wd_disable(void)
607{
608	u8 buf[32];
609	int ret;
610
611	i2c_set_bus_num(GSC_BUSNO);
612	ret = gsc_i2c_read(GSC_SC_ADDR, 0, buf, sizeof(buf));
613	if (!ret) {
614		buf[GSC_SC_CTRL1] |= BIT(GSC_SC_CTRL1_WDDIS);
615		ret = gsc_i2c_write(GSC_SC_ADDR, GSC_SC_CTRL1, &buf[GSC_SC_CTRL1], 1);
616		printf("GSCv%d: v%d 0x%04x ",
617		       memcmp(buf, buf + 16, 16) ? 3 : 2,
618		       buf[GSC_SC_FWVER],
619		       buf[GSC_SC_FWCRC] | buf[GSC_SC_FWCRC + 1] << 8);
620		if (buf[GSC_SC_STATUS] & BIT(GSC_SC_IRQ_WATCHDOG)) {
621			puts("RST:WDT ");
622			buf[GSC_SC_STATUS] &= ~BIT(GSC_SC_IRQ_WATCHDOG);
623			gsc_i2c_write(GSC_SC_ADDR, GSC_SC_STATUS, &buf[GSC_SC_STATUS], 1);
624		} else {
625			puts("RST:VIN ");
626		}
627		puts("WDT:disabled\n");
628	}
629
630	return ret;
631}
632
633#endif
634