1/*
2 * extcon-axp288.c - X-Power AXP288 PMIC extcon cable detection driver
3 *
4 * Copyright (C) 2015 Intel Corporation
5 * Author: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 */
16
17#include <linux/module.h>
18#include <linux/kernel.h>
19#include <linux/io.h>
20#include <linux/slab.h>
21#include <linux/interrupt.h>
22#include <linux/platform_device.h>
23#include <linux/property.h>
24#include <linux/usb/phy.h>
25#include <linux/notifier.h>
26#include <linux/extcon.h>
27#include <linux/regmap.h>
28#include <linux/gpio.h>
29#include <linux/gpio/consumer.h>
30#include <linux/mfd/axp20x.h>
31
32/* Power source status register */
33#define PS_STAT_VBUS_TRIGGER		BIT(0)
34#define PS_STAT_BAT_CHRG_DIR		BIT(2)
35#define PS_STAT_VBUS_ABOVE_VHOLD	BIT(3)
36#define PS_STAT_VBUS_VALID		BIT(4)
37#define PS_STAT_VBUS_PRESENT		BIT(5)
38
39/* BC module global register */
40#define BC_GLOBAL_RUN			BIT(0)
41#define BC_GLOBAL_DET_STAT		BIT(2)
42#define BC_GLOBAL_DBP_TOUT		BIT(3)
43#define BC_GLOBAL_VLGC_COM_SEL		BIT(4)
44#define BC_GLOBAL_DCD_TOUT_MASK		(BIT(6)|BIT(5))
45#define BC_GLOBAL_DCD_TOUT_300MS	0
46#define BC_GLOBAL_DCD_TOUT_100MS	1
47#define BC_GLOBAL_DCD_TOUT_500MS	2
48#define BC_GLOBAL_DCD_TOUT_900MS	3
49#define BC_GLOBAL_DCD_DET_SEL		BIT(7)
50
51/* BC module vbus control and status register */
52#define VBUS_CNTL_DPDM_PD_EN		BIT(4)
53#define VBUS_CNTL_DPDM_FD_EN		BIT(5)
54#define VBUS_CNTL_FIRST_PO_STAT		BIT(6)
55
56/* BC USB status register */
57#define USB_STAT_BUS_STAT_MASK		(BIT(3)|BIT(2)|BIT(1)|BIT(0))
58#define USB_STAT_BUS_STAT_SHIFT		0
59#define USB_STAT_BUS_STAT_ATHD		0
60#define USB_STAT_BUS_STAT_CONN		1
61#define USB_STAT_BUS_STAT_SUSP		2
62#define USB_STAT_BUS_STAT_CONF		3
63#define USB_STAT_USB_SS_MODE		BIT(4)
64#define USB_STAT_DEAD_BAT_DET		BIT(6)
65#define USB_STAT_DBP_UNCFG		BIT(7)
66
67/* BC detect status register */
68#define DET_STAT_MASK			(BIT(7)|BIT(6)|BIT(5))
69#define DET_STAT_SHIFT			5
70#define DET_STAT_SDP			1
71#define DET_STAT_CDP			2
72#define DET_STAT_DCP			3
73
74/* IRQ enable-1 register */
75#define PWRSRC_IRQ_CFG_MASK		(BIT(4)|BIT(3)|BIT(2))
76
77/* IRQ enable-6 register */
78#define BC12_IRQ_CFG_MASK		BIT(1)
79
80enum axp288_extcon_reg {
81	AXP288_PS_STAT_REG		= 0x00,
82	AXP288_PS_BOOT_REASON_REG	= 0x02,
83	AXP288_BC_GLOBAL_REG		= 0x2c,
84	AXP288_BC_VBUS_CNTL_REG		= 0x2d,
85	AXP288_BC_USB_STAT_REG		= 0x2e,
86	AXP288_BC_DET_STAT_REG		= 0x2f,
87	AXP288_PWRSRC_IRQ_CFG_REG	= 0x40,
88	AXP288_BC12_IRQ_CFG_REG		= 0x45,
89};
90
91enum axp288_mux_select {
92	EXTCON_GPIO_MUX_SEL_PMIC = 0,
93	EXTCON_GPIO_MUX_SEL_SOC,
94};
95
96enum axp288_extcon_irq {
97	VBUS_FALLING_IRQ = 0,
98	VBUS_RISING_IRQ,
99	MV_CHNG_IRQ,
100	BC_USB_CHNG_IRQ,
101	EXTCON_IRQ_END,
102};
103
104static const unsigned int axp288_extcon_cables[] = {
105	EXTCON_CHG_USB_SDP,
106	EXTCON_CHG_USB_CDP,
107	EXTCON_CHG_USB_DCP,
108	EXTCON_NONE,
109};
110
111struct axp288_extcon_info {
112	struct device *dev;
113	struct regmap *regmap;
114	struct regmap_irq_chip_data *regmap_irqc;
115	struct axp288_extcon_pdata *pdata;
116	int irq[EXTCON_IRQ_END];
117	struct extcon_dev *edev;
118	struct notifier_block extcon_nb;
119	struct usb_phy *otg;
120};
121
122/* Power up/down reason string array */
123static char *axp288_pwr_up_down_info[] = {
124	"Last wake caused by user pressing the power button",
125	"Last wake caused by a charger insertion",
126	"Last wake caused by a battery insertion",
127	"Last wake caused by SOC initiated global reset",
128	"Last wake caused by cold reset",
129	"Last shutdown caused by PMIC UVLO threshold",
130	"Last shutdown caused by SOC initiated cold off",
131	"Last shutdown caused by user pressing the power button",
132	NULL,
133};
134
135/*
136 * Decode and log the given "reset source indicator" (rsi)
137 * register and then clear it.
138 */
139static void axp288_extcon_log_rsi(struct axp288_extcon_info *info)
140{
141	char **rsi;
142	unsigned int val, i, clear_mask = 0;
143	int ret;
144
145	ret = regmap_read(info->regmap, AXP288_PS_BOOT_REASON_REG, &val);
146	for (i = 0, rsi = axp288_pwr_up_down_info; *rsi; rsi++, i++) {
147		if (val & BIT(i)) {
148			dev_dbg(info->dev, "%s\n", *rsi);
149			clear_mask |= BIT(i);
150		}
151	}
152
153	/* Clear the register value for next reboot (write 1 to clear bit) */
154	regmap_write(info->regmap, AXP288_PS_BOOT_REASON_REG, clear_mask);
155}
156
157static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info)
158{
159	static bool notify_otg, notify_charger;
160	static unsigned int cable;
161	int ret, stat, cfg, pwr_stat;
162	u8 chrg_type;
163	bool vbus_attach = false;
164
165	ret = regmap_read(info->regmap, AXP288_PS_STAT_REG, &pwr_stat);
166	if (ret < 0) {
167		dev_err(info->dev, "failed to read vbus status\n");
168		return ret;
169	}
170
171	vbus_attach = (pwr_stat & PS_STAT_VBUS_PRESENT);
172	if (!vbus_attach)
173		goto notify_otg;
174
175	/* Check charger detection completion status */
176	ret = regmap_read(info->regmap, AXP288_BC_GLOBAL_REG, &cfg);
177	if (ret < 0)
178		goto dev_det_ret;
179	if (cfg & BC_GLOBAL_DET_STAT) {
180		dev_dbg(info->dev, "can't complete the charger detection\n");
181		goto dev_det_ret;
182	}
183
184	ret = regmap_read(info->regmap, AXP288_BC_DET_STAT_REG, &stat);
185	if (ret < 0)
186		goto dev_det_ret;
187
188	chrg_type = (stat & DET_STAT_MASK) >> DET_STAT_SHIFT;
189
190	switch (chrg_type) {
191	case DET_STAT_SDP:
192		dev_dbg(info->dev, "sdp cable is connecetd\n");
193		notify_otg = true;
194		notify_charger = true;
195		cable = EXTCON_CHG_USB_SDP;
196		break;
197	case DET_STAT_CDP:
198		dev_dbg(info->dev, "cdp cable is connecetd\n");
199		notify_otg = true;
200		notify_charger = true;
201		cable = EXTCON_CHG_USB_CDP;
202		break;
203	case DET_STAT_DCP:
204		dev_dbg(info->dev, "dcp cable is connecetd\n");
205		notify_charger = true;
206		cable = EXTCON_CHG_USB_DCP;
207		break;
208	default:
209		dev_warn(info->dev,
210			"disconnect or unknown or ID event\n");
211	}
212
213notify_otg:
214	if (notify_otg) {
215		/*
216		 * If VBUS is absent Connect D+/D- lines to PMIC for BC
217		 * detection. Else connect them to SOC for USB communication.
218		 */
219		if (info->pdata->gpio_mux_cntl)
220			gpiod_set_value(info->pdata->gpio_mux_cntl,
221				vbus_attach ? EXTCON_GPIO_MUX_SEL_SOC
222						: EXTCON_GPIO_MUX_SEL_PMIC);
223
224		atomic_notifier_call_chain(&info->otg->notifier,
225			vbus_attach ? USB_EVENT_VBUS : USB_EVENT_NONE, NULL);
226	}
227
228	if (notify_charger)
229		extcon_set_cable_state_(info->edev, cable, vbus_attach);
230
231	/* Clear the flags on disconnect event */
232	if (!vbus_attach)
233		notify_otg = notify_charger = false;
234
235	return 0;
236
237dev_det_ret:
238	if (ret < 0)
239		dev_err(info->dev, "failed to detect BC Mod\n");
240
241	return ret;
242}
243
244static irqreturn_t axp288_extcon_isr(int irq, void *data)
245{
246	struct axp288_extcon_info *info = data;
247	int ret;
248
249	ret = axp288_handle_chrg_det_event(info);
250	if (ret < 0)
251		dev_err(info->dev, "failed to handle the interrupt\n");
252
253	return IRQ_HANDLED;
254}
255
256static void axp288_extcon_enable_irq(struct axp288_extcon_info *info)
257{
258	/* Unmask VBUS interrupt */
259	regmap_write(info->regmap, AXP288_PWRSRC_IRQ_CFG_REG,
260						PWRSRC_IRQ_CFG_MASK);
261	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
262						BC_GLOBAL_RUN, 0);
263	/* Unmask the BC1.2 complete interrupts */
264	regmap_write(info->regmap, AXP288_BC12_IRQ_CFG_REG, BC12_IRQ_CFG_MASK);
265	/* Enable the charger detection logic */
266	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
267					BC_GLOBAL_RUN, BC_GLOBAL_RUN);
268}
269
270static int axp288_extcon_probe(struct platform_device *pdev)
271{
272	struct axp288_extcon_info *info;
273	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
274	int ret, i, pirq, gpio;
275
276	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
277	if (!info)
278		return -ENOMEM;
279
280	info->dev = &pdev->dev;
281	info->regmap = axp20x->regmap;
282	info->regmap_irqc = axp20x->regmap_irqc;
283	info->pdata = pdev->dev.platform_data;
284
285	if (!info->pdata) {
286		/* Try ACPI provided pdata via device properties */
287		if (!device_property_present(&pdev->dev,
288					"axp288_extcon_data\n"))
289			dev_err(&pdev->dev, "failed to get platform data\n");
290		return -ENODEV;
291	}
292	platform_set_drvdata(pdev, info);
293
294	axp288_extcon_log_rsi(info);
295
296	/* Initialize extcon device */
297	info->edev = devm_extcon_dev_allocate(&pdev->dev,
298					      axp288_extcon_cables);
299	if (IS_ERR(info->edev)) {
300		dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
301		return PTR_ERR(info->edev);
302	}
303
304	/* Register extcon device */
305	ret = devm_extcon_dev_register(&pdev->dev, info->edev);
306	if (ret) {
307		dev_err(&pdev->dev, "failed to register extcon device\n");
308		return ret;
309	}
310
311	/* Get otg transceiver phy */
312	info->otg = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
313	if (IS_ERR(info->otg)) {
314		dev_err(&pdev->dev, "failed to get otg transceiver\n");
315		return PTR_ERR(info->otg);
316	}
317
318	/* Set up gpio control for USB Mux */
319	if (info->pdata->gpio_mux_cntl) {
320		gpio = desc_to_gpio(info->pdata->gpio_mux_cntl);
321		ret = devm_gpio_request(&pdev->dev, gpio, "USB_MUX");
322		if (ret < 0) {
323			dev_err(&pdev->dev,
324				"failed to request the gpio=%d\n", gpio);
325			return ret;
326		}
327		gpiod_direction_output(info->pdata->gpio_mux_cntl,
328						EXTCON_GPIO_MUX_SEL_PMIC);
329	}
330
331	for (i = 0; i < EXTCON_IRQ_END; i++) {
332		pirq = platform_get_irq(pdev, i);
333		info->irq[i] = regmap_irq_get_virq(info->regmap_irqc, pirq);
334		if (info->irq[i] < 0) {
335			dev_err(&pdev->dev,
336				"failed to get virtual interrupt=%d\n", pirq);
337			ret = info->irq[i];
338			return ret;
339		}
340
341		ret = devm_request_threaded_irq(&pdev->dev, info->irq[i],
342				NULL, axp288_extcon_isr,
343				IRQF_ONESHOT | IRQF_NO_SUSPEND,
344				pdev->name, info);
345		if (ret) {
346			dev_err(&pdev->dev, "failed to request interrupt=%d\n",
347							info->irq[i]);
348			return ret;
349		}
350	}
351
352	/* Enable interrupts */
353	axp288_extcon_enable_irq(info);
354
355	return 0;
356}
357
358static struct platform_driver axp288_extcon_driver = {
359	.probe = axp288_extcon_probe,
360	.driver = {
361		.name = "axp288_extcon",
362	},
363};
364module_platform_driver(axp288_extcon_driver);
365
366MODULE_AUTHOR("Ramakrishna Pallala <ramakrishna.pallala@intel.com>");
367MODULE_DESCRIPTION("X-Powers AXP288 extcon driver");
368MODULE_LICENSE("GPL v2");
369