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/notifier.h>
25 #include <linux/extcon.h>
26 #include <linux/regmap.h>
27 #include <linux/gpio.h>
28 #include <linux/gpio/consumer.h>
29 #include <linux/mfd/axp20x.h>
30 
31 /* Power source status register */
32 #define PS_STAT_VBUS_TRIGGER		BIT(0)
33 #define PS_STAT_BAT_CHRG_DIR		BIT(2)
34 #define PS_STAT_VBUS_ABOVE_VHOLD	BIT(3)
35 #define PS_STAT_VBUS_VALID		BIT(4)
36 #define PS_STAT_VBUS_PRESENT		BIT(5)
37 
38 /* BC module global register */
39 #define BC_GLOBAL_RUN			BIT(0)
40 #define BC_GLOBAL_DET_STAT		BIT(2)
41 #define BC_GLOBAL_DBP_TOUT		BIT(3)
42 #define BC_GLOBAL_VLGC_COM_SEL		BIT(4)
43 #define BC_GLOBAL_DCD_TOUT_MASK		(BIT(6)|BIT(5))
44 #define BC_GLOBAL_DCD_TOUT_300MS	0
45 #define BC_GLOBAL_DCD_TOUT_100MS	1
46 #define BC_GLOBAL_DCD_TOUT_500MS	2
47 #define BC_GLOBAL_DCD_TOUT_900MS	3
48 #define BC_GLOBAL_DCD_DET_SEL		BIT(7)
49 
50 /* BC module vbus control and status register */
51 #define VBUS_CNTL_DPDM_PD_EN		BIT(4)
52 #define VBUS_CNTL_DPDM_FD_EN		BIT(5)
53 #define VBUS_CNTL_FIRST_PO_STAT		BIT(6)
54 
55 /* BC USB status register */
56 #define USB_STAT_BUS_STAT_MASK		(BIT(3)|BIT(2)|BIT(1)|BIT(0))
57 #define USB_STAT_BUS_STAT_SHIFT		0
58 #define USB_STAT_BUS_STAT_ATHD		0
59 #define USB_STAT_BUS_STAT_CONN		1
60 #define USB_STAT_BUS_STAT_SUSP		2
61 #define USB_STAT_BUS_STAT_CONF		3
62 #define USB_STAT_USB_SS_MODE		BIT(4)
63 #define USB_STAT_DEAD_BAT_DET		BIT(6)
64 #define USB_STAT_DBP_UNCFG		BIT(7)
65 
66 /* BC detect status register */
67 #define DET_STAT_MASK			(BIT(7)|BIT(6)|BIT(5))
68 #define DET_STAT_SHIFT			5
69 #define DET_STAT_SDP			1
70 #define DET_STAT_CDP			2
71 #define DET_STAT_DCP			3
72 
73 enum axp288_extcon_reg {
74 	AXP288_PS_STAT_REG		= 0x00,
75 	AXP288_PS_BOOT_REASON_REG	= 0x02,
76 	AXP288_BC_GLOBAL_REG		= 0x2c,
77 	AXP288_BC_VBUS_CNTL_REG		= 0x2d,
78 	AXP288_BC_USB_STAT_REG		= 0x2e,
79 	AXP288_BC_DET_STAT_REG		= 0x2f,
80 };
81 
82 enum axp288_mux_select {
83 	EXTCON_GPIO_MUX_SEL_PMIC = 0,
84 	EXTCON_GPIO_MUX_SEL_SOC,
85 };
86 
87 enum axp288_extcon_irq {
88 	VBUS_FALLING_IRQ = 0,
89 	VBUS_RISING_IRQ,
90 	MV_CHNG_IRQ,
91 	BC_USB_CHNG_IRQ,
92 	EXTCON_IRQ_END,
93 };
94 
95 static const unsigned int axp288_extcon_cables[] = {
96 	EXTCON_CHG_USB_SDP,
97 	EXTCON_CHG_USB_CDP,
98 	EXTCON_CHG_USB_DCP,
99 	EXTCON_USB,
100 	EXTCON_NONE,
101 };
102 
103 struct axp288_extcon_info {
104 	struct device *dev;
105 	struct regmap *regmap;
106 	struct regmap_irq_chip_data *regmap_irqc;
107 	struct gpio_desc *gpio_mux_cntl;
108 	int irq[EXTCON_IRQ_END];
109 	struct extcon_dev *edev;
110 	struct notifier_block extcon_nb;
111 	unsigned int previous_cable;
112 };
113 
114 /* Power up/down reason string array */
115 static char *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 	NULL,
125 };
126 
127 /*
128  * Decode and log the given "reset source indicator" (rsi)
129  * register and then clear it.
130  */
131 static void axp288_extcon_log_rsi(struct axp288_extcon_info *info)
132 {
133 	char **rsi;
134 	unsigned int val, i, clear_mask = 0;
135 	int ret;
136 
137 	ret = regmap_read(info->regmap, AXP288_PS_BOOT_REASON_REG, &val);
138 	for (i = 0, rsi = axp288_pwr_up_down_info; *rsi; rsi++, i++) {
139 		if (val & BIT(i)) {
140 			dev_dbg(info->dev, "%s\n", *rsi);
141 			clear_mask |= BIT(i);
142 		}
143 	}
144 
145 	/* Clear the register value for next reboot (write 1 to clear bit) */
146 	regmap_write(info->regmap, AXP288_PS_BOOT_REASON_REG, clear_mask);
147 }
148 
149 static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info)
150 {
151 	int ret, stat, cfg, pwr_stat;
152 	u8 chrg_type;
153 	unsigned int cable = info->previous_cable;
154 	bool vbus_attach = false;
155 
156 	ret = regmap_read(info->regmap, AXP288_PS_STAT_REG, &pwr_stat);
157 	if (ret < 0) {
158 		dev_err(info->dev, "failed to read vbus status\n");
159 		return ret;
160 	}
161 
162 	vbus_attach = (pwr_stat & PS_STAT_VBUS_VALID);
163 	if (!vbus_attach)
164 		goto no_vbus;
165 
166 	/* Check charger detection completion status */
167 	ret = regmap_read(info->regmap, AXP288_BC_GLOBAL_REG, &cfg);
168 	if (ret < 0)
169 		goto dev_det_ret;
170 	if (cfg & BC_GLOBAL_DET_STAT) {
171 		dev_dbg(info->dev, "can't complete the charger detection\n");
172 		goto dev_det_ret;
173 	}
174 
175 	ret = regmap_read(info->regmap, AXP288_BC_DET_STAT_REG, &stat);
176 	if (ret < 0)
177 		goto dev_det_ret;
178 
179 	chrg_type = (stat & DET_STAT_MASK) >> DET_STAT_SHIFT;
180 
181 	switch (chrg_type) {
182 	case DET_STAT_SDP:
183 		dev_dbg(info->dev, "sdp cable is connected\n");
184 		cable = EXTCON_CHG_USB_SDP;
185 		break;
186 	case DET_STAT_CDP:
187 		dev_dbg(info->dev, "cdp cable is connected\n");
188 		cable = EXTCON_CHG_USB_CDP;
189 		break;
190 	case DET_STAT_DCP:
191 		dev_dbg(info->dev, "dcp cable is connected\n");
192 		cable = EXTCON_CHG_USB_DCP;
193 		break;
194 	default:
195 		dev_warn(info->dev,
196 			"disconnect or unknown or ID event\n");
197 	}
198 
199 no_vbus:
200 	/*
201 	 * If VBUS is absent Connect D+/D- lines to PMIC for BC
202 	 * detection. Else connect them to SOC for USB communication.
203 	 */
204 	if (info->gpio_mux_cntl)
205 		gpiod_set_value(info->gpio_mux_cntl,
206 			vbus_attach ? EXTCON_GPIO_MUX_SEL_SOC
207 					: EXTCON_GPIO_MUX_SEL_PMIC);
208 
209 	extcon_set_state_sync(info->edev, info->previous_cable, false);
210 	if (info->previous_cable == EXTCON_CHG_USB_SDP)
211 		extcon_set_state_sync(info->edev, EXTCON_USB, false);
212 
213 	if (vbus_attach) {
214 		extcon_set_state_sync(info->edev, cable, vbus_attach);
215 		if (cable == EXTCON_CHG_USB_SDP)
216 			extcon_set_state_sync(info->edev, EXTCON_USB,
217 						vbus_attach);
218 
219 		info->previous_cable = cable;
220 	}
221 
222 	return 0;
223 
224 dev_det_ret:
225 	if (ret < 0)
226 		dev_err(info->dev, "failed to detect BC Mod\n");
227 
228 	return ret;
229 }
230 
231 static irqreturn_t axp288_extcon_isr(int irq, void *data)
232 {
233 	struct axp288_extcon_info *info = data;
234 	int ret;
235 
236 	ret = axp288_handle_chrg_det_event(info);
237 	if (ret < 0)
238 		dev_err(info->dev, "failed to handle the interrupt\n");
239 
240 	return IRQ_HANDLED;
241 }
242 
243 static void axp288_extcon_enable(struct axp288_extcon_info *info)
244 {
245 	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
246 						BC_GLOBAL_RUN, 0);
247 	/* Enable the charger detection logic */
248 	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
249 					BC_GLOBAL_RUN, BC_GLOBAL_RUN);
250 }
251 
252 static int axp288_extcon_probe(struct platform_device *pdev)
253 {
254 	struct axp288_extcon_info *info;
255 	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
256 	struct axp288_extcon_pdata *pdata = pdev->dev.platform_data;
257 	int ret, i, pirq, gpio;
258 
259 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
260 	if (!info)
261 		return -ENOMEM;
262 
263 	info->dev = &pdev->dev;
264 	info->regmap = axp20x->regmap;
265 	info->regmap_irqc = axp20x->regmap_irqc;
266 	info->previous_cable = EXTCON_NONE;
267 	if (pdata)
268 		info->gpio_mux_cntl = pdata->gpio_mux_cntl;
269 
270 	platform_set_drvdata(pdev, info);
271 
272 	axp288_extcon_log_rsi(info);
273 
274 	/* Initialize extcon device */
275 	info->edev = devm_extcon_dev_allocate(&pdev->dev,
276 					      axp288_extcon_cables);
277 	if (IS_ERR(info->edev)) {
278 		dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
279 		return PTR_ERR(info->edev);
280 	}
281 
282 	/* Register extcon device */
283 	ret = devm_extcon_dev_register(&pdev->dev, info->edev);
284 	if (ret) {
285 		dev_err(&pdev->dev, "failed to register extcon device\n");
286 		return ret;
287 	}
288 
289 	/* Set up gpio control for USB Mux */
290 	if (info->gpio_mux_cntl) {
291 		gpio = desc_to_gpio(info->gpio_mux_cntl);
292 		ret = devm_gpio_request(&pdev->dev, gpio, "USB_MUX");
293 		if (ret < 0) {
294 			dev_err(&pdev->dev,
295 				"failed to request the gpio=%d\n", gpio);
296 			return ret;
297 		}
298 		gpiod_direction_output(info->gpio_mux_cntl,
299 						EXTCON_GPIO_MUX_SEL_PMIC);
300 	}
301 
302 	for (i = 0; i < EXTCON_IRQ_END; i++) {
303 		pirq = platform_get_irq(pdev, i);
304 		info->irq[i] = regmap_irq_get_virq(info->regmap_irqc, pirq);
305 		if (info->irq[i] < 0) {
306 			dev_err(&pdev->dev,
307 				"failed to get virtual interrupt=%d\n", pirq);
308 			ret = info->irq[i];
309 			return ret;
310 		}
311 
312 		ret = devm_request_threaded_irq(&pdev->dev, info->irq[i],
313 				NULL, axp288_extcon_isr,
314 				IRQF_ONESHOT | IRQF_NO_SUSPEND,
315 				pdev->name, info);
316 		if (ret) {
317 			dev_err(&pdev->dev, "failed to request interrupt=%d\n",
318 							info->irq[i]);
319 			return ret;
320 		}
321 	}
322 
323 	/* Start charger cable type detection */
324 	axp288_extcon_enable(info);
325 
326 	return 0;
327 }
328 
329 static const struct platform_device_id axp288_extcon_table[] = {
330 	{ .name = "axp288_extcon" },
331 	{},
332 };
333 MODULE_DEVICE_TABLE(platform, axp288_extcon_table);
334 
335 static struct platform_driver axp288_extcon_driver = {
336 	.probe = axp288_extcon_probe,
337 	.id_table = axp288_extcon_table,
338 	.driver = {
339 		.name = "axp288_extcon",
340 	},
341 };
342 module_platform_driver(axp288_extcon_driver);
343 
344 MODULE_AUTHOR("Ramakrishna Pallala <ramakrishna.pallala@intel.com>");
345 MODULE_DESCRIPTION("X-Powers AXP288 extcon driver");
346 MODULE_LICENSE("GPL v2");
347