1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * extcon-axp288.c - X-Power AXP288 PMIC extcon cable detection driver
4  *
5  * Copyright (c) 2017-2018 Hans de Goede <hdegoede@redhat.com>
6  * Copyright (C) 2015 Intel Corporation
7  * Author: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
8  */
9 
10 #include <linux/acpi.h>
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/io.h>
14 #include <linux/slab.h>
15 #include <linux/interrupt.h>
16 #include <linux/platform_device.h>
17 #include <linux/property.h>
18 #include <linux/notifier.h>
19 #include <linux/extcon-provider.h>
20 #include <linux/regmap.h>
21 #include <linux/mfd/axp20x.h>
22 #include <linux/usb/role.h>
23 #include <linux/workqueue.h>
24 
25 #include <asm/cpu_device_id.h>
26 #include <asm/intel-family.h>
27 
28 /* Power source status register */
29 #define PS_STAT_VBUS_TRIGGER		BIT(0)
30 #define PS_STAT_BAT_CHRG_DIR		BIT(2)
31 #define PS_STAT_VBUS_ABOVE_VHOLD	BIT(3)
32 #define PS_STAT_VBUS_VALID		BIT(4)
33 #define PS_STAT_VBUS_PRESENT		BIT(5)
34 
35 /* BC module global register */
36 #define BC_GLOBAL_RUN			BIT(0)
37 #define BC_GLOBAL_DET_STAT		BIT(2)
38 #define BC_GLOBAL_DBP_TOUT		BIT(3)
39 #define BC_GLOBAL_VLGC_COM_SEL		BIT(4)
40 #define BC_GLOBAL_DCD_TOUT_MASK		(BIT(6)|BIT(5))
41 #define BC_GLOBAL_DCD_TOUT_300MS	0
42 #define BC_GLOBAL_DCD_TOUT_100MS	1
43 #define BC_GLOBAL_DCD_TOUT_500MS	2
44 #define BC_GLOBAL_DCD_TOUT_900MS	3
45 #define BC_GLOBAL_DCD_DET_SEL		BIT(7)
46 
47 /* BC module vbus control and status register */
48 #define VBUS_CNTL_DPDM_PD_EN		BIT(4)
49 #define VBUS_CNTL_DPDM_FD_EN		BIT(5)
50 #define VBUS_CNTL_FIRST_PO_STAT		BIT(6)
51 
52 /* BC USB status register */
53 #define USB_STAT_BUS_STAT_MASK		(BIT(3)|BIT(2)|BIT(1)|BIT(0))
54 #define USB_STAT_BUS_STAT_SHIFT		0
55 #define USB_STAT_BUS_STAT_ATHD		0
56 #define USB_STAT_BUS_STAT_CONN		1
57 #define USB_STAT_BUS_STAT_SUSP		2
58 #define USB_STAT_BUS_STAT_CONF		3
59 #define USB_STAT_USB_SS_MODE		BIT(4)
60 #define USB_STAT_DEAD_BAT_DET		BIT(6)
61 #define USB_STAT_DBP_UNCFG		BIT(7)
62 
63 /* BC detect status register */
64 #define DET_STAT_MASK			(BIT(7)|BIT(6)|BIT(5))
65 #define DET_STAT_SHIFT			5
66 #define DET_STAT_SDP			1
67 #define DET_STAT_CDP			2
68 #define DET_STAT_DCP			3
69 
70 enum axp288_extcon_reg {
71 	AXP288_PS_STAT_REG		= 0x00,
72 	AXP288_PS_BOOT_REASON_REG	= 0x02,
73 	AXP288_BC_GLOBAL_REG		= 0x2c,
74 	AXP288_BC_VBUS_CNTL_REG		= 0x2d,
75 	AXP288_BC_USB_STAT_REG		= 0x2e,
76 	AXP288_BC_DET_STAT_REG		= 0x2f,
77 };
78 
79 enum axp288_extcon_irq {
80 	VBUS_FALLING_IRQ = 0,
81 	VBUS_RISING_IRQ,
82 	MV_CHNG_IRQ,
83 	BC_USB_CHNG_IRQ,
84 	EXTCON_IRQ_END,
85 };
86 
87 static const unsigned int axp288_extcon_cables[] = {
88 	EXTCON_CHG_USB_SDP,
89 	EXTCON_CHG_USB_CDP,
90 	EXTCON_CHG_USB_DCP,
91 	EXTCON_USB,
92 	EXTCON_NONE,
93 };
94 
95 struct axp288_extcon_info {
96 	struct device *dev;
97 	struct regmap *regmap;
98 	struct regmap_irq_chip_data *regmap_irqc;
99 	struct usb_role_switch *role_sw;
100 	struct work_struct role_work;
101 	int irq[EXTCON_IRQ_END];
102 	struct extcon_dev *edev;
103 	struct extcon_dev *id_extcon;
104 	struct notifier_block id_nb;
105 	unsigned int previous_cable;
106 	bool vbus_attach;
107 };
108 
109 static const struct x86_cpu_id cherry_trail_cpu_ids[] = {
110 	{ X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT, X86_FEATURE_ANY },
111 	{}
112 };
113 
114 /* Power up/down reason string array */
115 static const char * const axp288_pwr_up_down_info[] = {
116 	"Last wake caused by user pressing the power button",
117 	"Last wake caused by a charger insertion",
118 	"Last wake caused by a battery insertion",
119 	"Last wake caused by SOC initiated global reset",
120 	"Last wake caused by cold reset",
121 	"Last shutdown caused by PMIC UVLO threshold",
122 	"Last shutdown caused by SOC initiated cold off",
123 	"Last shutdown caused by user pressing the power button",
124 };
125 
126 /*
127  * Decode and log the given "reset source indicator" (rsi)
128  * register and then clear it.
129  */
130 static void axp288_extcon_log_rsi(struct axp288_extcon_info *info)
131 {
132 	unsigned int val, i, clear_mask = 0;
133 	unsigned long bits;
134 	int ret;
135 
136 	ret = regmap_read(info->regmap, AXP288_PS_BOOT_REASON_REG, &val);
137 	if (ret < 0) {
138 		dev_err(info->dev, "failed to read reset source indicator\n");
139 		return;
140 	}
141 
142 	bits = val & GENMASK(ARRAY_SIZE(axp288_pwr_up_down_info) - 1, 0);
143 	for_each_set_bit(i, &bits, ARRAY_SIZE(axp288_pwr_up_down_info))
144 		dev_dbg(info->dev, "%s\n", axp288_pwr_up_down_info[i]);
145 	clear_mask = bits;
146 
147 	/* Clear the register value for next reboot (write 1 to clear bit) */
148 	regmap_write(info->regmap, AXP288_PS_BOOT_REASON_REG, clear_mask);
149 }
150 
151 /*
152  * The below code to control the USB role-switch on devices with an AXP288
153  * may seem out of place, but there are 2 reasons why this is the best place
154  * to control the USB role-switch on such devices:
155  * 1) On many devices the USB role is controlled by AML code, but the AML code
156  *    only switches between the host and none roles, because of Windows not
157  *    really using device mode. To make device mode work we need to toggle
158  *    between the none/device roles based on Vbus presence, and this driver
159  *    gets interrupts on Vbus insertion / removal.
160  * 2) In order for our BC1.2 charger detection to work properly the role
161  *    mux must be properly set to device mode before we do the detection.
162  */
163 
164 /* Returns the id-pin value, note pulled low / false == host-mode */
165 static bool axp288_get_id_pin(struct axp288_extcon_info *info)
166 {
167 	enum usb_role role;
168 
169 	if (info->id_extcon)
170 		return extcon_get_state(info->id_extcon, EXTCON_USB_HOST) <= 0;
171 
172 	/* We cannot access the id-pin, see what mode the AML code has set */
173 	role = usb_role_switch_get_role(info->role_sw);
174 	return role != USB_ROLE_HOST;
175 }
176 
177 static void axp288_usb_role_work(struct work_struct *work)
178 {
179 	struct axp288_extcon_info *info =
180 		container_of(work, struct axp288_extcon_info, role_work);
181 	enum usb_role role;
182 	bool id_pin;
183 	int ret;
184 
185 	id_pin = axp288_get_id_pin(info);
186 	if (!id_pin)
187 		role = USB_ROLE_HOST;
188 	else if (info->vbus_attach)
189 		role = USB_ROLE_DEVICE;
190 	else
191 		role = USB_ROLE_NONE;
192 
193 	ret = usb_role_switch_set_role(info->role_sw, role);
194 	if (ret)
195 		dev_err(info->dev, "failed to set role: %d\n", ret);
196 }
197 
198 static bool axp288_get_vbus_attach(struct axp288_extcon_info *info)
199 {
200 	int ret, pwr_stat;
201 
202 	ret = regmap_read(info->regmap, AXP288_PS_STAT_REG, &pwr_stat);
203 	if (ret < 0) {
204 		dev_err(info->dev, "failed to read vbus status\n");
205 		return false;
206 	}
207 
208 	return !!(pwr_stat & PS_STAT_VBUS_VALID);
209 }
210 
211 static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info)
212 {
213 	int ret, stat, cfg;
214 	u8 chrg_type;
215 	unsigned int cable = info->previous_cable;
216 	bool vbus_attach = false;
217 
218 	vbus_attach = axp288_get_vbus_attach(info);
219 	if (!vbus_attach)
220 		goto no_vbus;
221 
222 	/* Check charger detection completion status */
223 	ret = regmap_read(info->regmap, AXP288_BC_GLOBAL_REG, &cfg);
224 	if (ret < 0)
225 		goto dev_det_ret;
226 	if (cfg & BC_GLOBAL_DET_STAT) {
227 		dev_dbg(info->dev, "can't complete the charger detection\n");
228 		goto dev_det_ret;
229 	}
230 
231 	ret = regmap_read(info->regmap, AXP288_BC_DET_STAT_REG, &stat);
232 	if (ret < 0)
233 		goto dev_det_ret;
234 
235 	chrg_type = (stat & DET_STAT_MASK) >> DET_STAT_SHIFT;
236 
237 	switch (chrg_type) {
238 	case DET_STAT_SDP:
239 		dev_dbg(info->dev, "sdp cable is connected\n");
240 		cable = EXTCON_CHG_USB_SDP;
241 		break;
242 	case DET_STAT_CDP:
243 		dev_dbg(info->dev, "cdp cable is connected\n");
244 		cable = EXTCON_CHG_USB_CDP;
245 		break;
246 	case DET_STAT_DCP:
247 		dev_dbg(info->dev, "dcp cable is connected\n");
248 		cable = EXTCON_CHG_USB_DCP;
249 		break;
250 	default:
251 		dev_warn(info->dev, "unknown (reserved) bc detect result\n");
252 		cable = EXTCON_CHG_USB_SDP;
253 	}
254 
255 no_vbus:
256 	extcon_set_state_sync(info->edev, info->previous_cable, false);
257 	if (info->previous_cable == EXTCON_CHG_USB_SDP)
258 		extcon_set_state_sync(info->edev, EXTCON_USB, false);
259 
260 	if (vbus_attach) {
261 		extcon_set_state_sync(info->edev, cable, vbus_attach);
262 		if (cable == EXTCON_CHG_USB_SDP)
263 			extcon_set_state_sync(info->edev, EXTCON_USB,
264 						vbus_attach);
265 
266 		info->previous_cable = cable;
267 	}
268 
269 	if (info->role_sw && info->vbus_attach != vbus_attach) {
270 		info->vbus_attach = vbus_attach;
271 		/* Setting the role can take a while */
272 		queue_work(system_long_wq, &info->role_work);
273 	}
274 
275 	return 0;
276 
277 dev_det_ret:
278 	if (ret < 0)
279 		dev_err(info->dev, "failed to detect BC Mod\n");
280 
281 	return ret;
282 }
283 
284 static int axp288_extcon_id_evt(struct notifier_block *nb,
285 				unsigned long event, void *param)
286 {
287 	struct axp288_extcon_info *info =
288 		container_of(nb, struct axp288_extcon_info, id_nb);
289 
290 	/* We may not sleep and setting the role can take a while */
291 	queue_work(system_long_wq, &info->role_work);
292 
293 	return NOTIFY_OK;
294 }
295 
296 static irqreturn_t axp288_extcon_isr(int irq, void *data)
297 {
298 	struct axp288_extcon_info *info = data;
299 	int ret;
300 
301 	ret = axp288_handle_chrg_det_event(info);
302 	if (ret < 0)
303 		dev_err(info->dev, "failed to handle the interrupt\n");
304 
305 	return IRQ_HANDLED;
306 }
307 
308 static void axp288_extcon_enable(struct axp288_extcon_info *info)
309 {
310 	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
311 						BC_GLOBAL_RUN, 0);
312 	/* Enable the charger detection logic */
313 	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
314 					BC_GLOBAL_RUN, BC_GLOBAL_RUN);
315 }
316 
317 static void axp288_put_role_sw(void *data)
318 {
319 	struct axp288_extcon_info *info = data;
320 
321 	cancel_work_sync(&info->role_work);
322 	usb_role_switch_put(info->role_sw);
323 }
324 
325 static int axp288_extcon_probe(struct platform_device *pdev)
326 {
327 	struct axp288_extcon_info *info;
328 	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
329 	struct device *dev = &pdev->dev;
330 	struct acpi_device *adev;
331 	int ret, i, pirq;
332 
333 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
334 	if (!info)
335 		return -ENOMEM;
336 
337 	info->dev = &pdev->dev;
338 	info->regmap = axp20x->regmap;
339 	info->regmap_irqc = axp20x->regmap_irqc;
340 	info->previous_cable = EXTCON_NONE;
341 	INIT_WORK(&info->role_work, axp288_usb_role_work);
342 	info->id_nb.notifier_call = axp288_extcon_id_evt;
343 
344 	platform_set_drvdata(pdev, info);
345 
346 	info->role_sw = usb_role_switch_get(dev);
347 	if (IS_ERR(info->role_sw))
348 		return PTR_ERR(info->role_sw);
349 	if (info->role_sw) {
350 		ret = devm_add_action_or_reset(dev, axp288_put_role_sw, info);
351 		if (ret)
352 			return ret;
353 
354 		adev = acpi_dev_get_first_match_dev("INT3496", NULL, -1);
355 		if (adev) {
356 			info->id_extcon = extcon_get_extcon_dev(acpi_dev_name(adev));
357 			put_device(&adev->dev);
358 			if (!info->id_extcon)
359 				return -EPROBE_DEFER;
360 
361 			dev_info(dev, "controlling USB role\n");
362 		} else {
363 			dev_info(dev, "controlling USB role based on Vbus presence\n");
364 		}
365 	}
366 
367 	info->vbus_attach = axp288_get_vbus_attach(info);
368 
369 	axp288_extcon_log_rsi(info);
370 
371 	/* Initialize extcon device */
372 	info->edev = devm_extcon_dev_allocate(&pdev->dev,
373 					      axp288_extcon_cables);
374 	if (IS_ERR(info->edev)) {
375 		dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
376 		return PTR_ERR(info->edev);
377 	}
378 
379 	/* Register extcon device */
380 	ret = devm_extcon_dev_register(&pdev->dev, info->edev);
381 	if (ret) {
382 		dev_err(&pdev->dev, "failed to register extcon device\n");
383 		return ret;
384 	}
385 
386 	for (i = 0; i < EXTCON_IRQ_END; i++) {
387 		pirq = platform_get_irq(pdev, i);
388 		if (pirq < 0)
389 			return pirq;
390 
391 		info->irq[i] = regmap_irq_get_virq(info->regmap_irqc, pirq);
392 		if (info->irq[i] < 0) {
393 			dev_err(&pdev->dev,
394 				"failed to get virtual interrupt=%d\n", pirq);
395 			ret = info->irq[i];
396 			return ret;
397 		}
398 
399 		ret = devm_request_threaded_irq(&pdev->dev, info->irq[i],
400 				NULL, axp288_extcon_isr,
401 				IRQF_ONESHOT | IRQF_NO_SUSPEND,
402 				pdev->name, info);
403 		if (ret) {
404 			dev_err(&pdev->dev, "failed to request interrupt=%d\n",
405 							info->irq[i]);
406 			return ret;
407 		}
408 	}
409 
410 	if (info->id_extcon) {
411 		ret = devm_extcon_register_notifier_all(dev, info->id_extcon,
412 							&info->id_nb);
413 		if (ret)
414 			return ret;
415 	}
416 
417 	/* Make sure the role-sw is set correctly before doing BC detection */
418 	if (info->role_sw) {
419 		queue_work(system_long_wq, &info->role_work);
420 		flush_work(&info->role_work);
421 	}
422 
423 	/* Start charger cable type detection */
424 	axp288_extcon_enable(info);
425 
426 	return 0;
427 }
428 
429 static const struct platform_device_id axp288_extcon_table[] = {
430 	{ .name = "axp288_extcon" },
431 	{},
432 };
433 MODULE_DEVICE_TABLE(platform, axp288_extcon_table);
434 
435 static struct platform_driver axp288_extcon_driver = {
436 	.probe = axp288_extcon_probe,
437 	.id_table = axp288_extcon_table,
438 	.driver = {
439 		.name = "axp288_extcon",
440 	},
441 };
442 
443 static struct device_connection axp288_extcon_role_sw_conn = {
444 	.endpoint[0] = "axp288_extcon",
445 	.endpoint[1] = "intel_xhci_usb_sw-role-switch",
446 	.id = "usb-role-switch",
447 };
448 
449 static int __init axp288_extcon_init(void)
450 {
451 	if (x86_match_cpu(cherry_trail_cpu_ids))
452 		device_connection_add(&axp288_extcon_role_sw_conn);
453 
454 	return platform_driver_register(&axp288_extcon_driver);
455 }
456 module_init(axp288_extcon_init);
457 
458 static void __exit axp288_extcon_exit(void)
459 {
460 	if (x86_match_cpu(cherry_trail_cpu_ids))
461 		device_connection_remove(&axp288_extcon_role_sw_conn);
462 
463 	platform_driver_unregister(&axp288_extcon_driver);
464 }
465 module_exit(axp288_extcon_exit);
466 
467 MODULE_AUTHOR("Ramakrishna Pallala <ramakrishna.pallala@intel.com>");
468 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
469 MODULE_DESCRIPTION("X-Powers AXP288 extcon driver");
470 MODULE_LICENSE("GPL v2");
471