1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Poweroff & reset driver for Actions Semi ATC260x PMICs
4  *
5  * Copyright (c) 2020 Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
6  */
7 
8 #include <linux/delay.h>
9 #include <linux/mfd/atc260x/core.h>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/power_supply.h>
13 #include <linux/reboot.h>
14 #include <linux/regmap.h>
15 
16 struct atc260x_pwrc {
17 	struct device *dev;
18 	struct regmap *regmap;
19 	struct notifier_block restart_nb;
20 	int (*do_poweroff)(const struct atc260x_pwrc *pwrc, bool restart);
21 };
22 
23 /* Global variable needed only for pm_power_off */
24 static struct atc260x_pwrc *atc260x_pwrc_data;
25 
26 static int atc2603c_do_poweroff(const struct atc260x_pwrc *pwrc, bool restart)
27 {
28 	int ret, deep_sleep = 0;
29 	uint reg_mask, reg_val;
30 
31 	/* S4-Deep Sleep Mode is NOT available for WALL/USB power */
32 	if (!restart && !power_supply_is_system_supplied()) {
33 		deep_sleep = 1;
34 		dev_info(pwrc->dev, "Enabling S4-Deep Sleep Mode");
35 	}
36 
37 	/* Update wakeup sources */
38 	reg_val = ATC2603C_PMU_SYS_CTL0_ONOFF_LONG_WK_EN |
39 		  (restart ? ATC2603C_PMU_SYS_CTL0_RESET_WK_EN
40 			   : ATC2603C_PMU_SYS_CTL0_ONOFF_SHORT_WK_EN);
41 
42 	ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL0,
43 				 ATC2603C_PMU_SYS_CTL0_WK_ALL, reg_val);
44 	if (ret)
45 		dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);
46 
47 	/* Update power mode */
48 	reg_mask = ATC2603C_PMU_SYS_CTL3_EN_S2 | ATC2603C_PMU_SYS_CTL3_EN_S3;
49 
50 	ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL3, reg_mask,
51 				 deep_sleep ? 0 : ATC2603C_PMU_SYS_CTL3_EN_S3);
52 	if (ret) {
53 		dev_err(pwrc->dev, "failed to write SYS_CTL3: %d\n", ret);
54 		return ret;
55 	}
56 
57 	/* Trigger poweroff / restart sequence */
58 	reg_mask = restart ? ATC2603C_PMU_SYS_CTL0_RESTART_EN
59 			   : ATC2603C_PMU_SYS_CTL1_EN_S1;
60 	reg_val = restart ? ATC2603C_PMU_SYS_CTL0_RESTART_EN : 0;
61 
62 	ret = regmap_update_bits(pwrc->regmap,
63 				 restart ? ATC2603C_PMU_SYS_CTL0 : ATC2603C_PMU_SYS_CTL1,
64 				 reg_mask, reg_val);
65 	if (ret) {
66 		dev_err(pwrc->dev, "failed to write SYS_CTL%d: %d\n",
67 			restart ? 0 : 1, ret);
68 		return ret;
69 	}
70 
71 	/* Wait for trigger completion */
72 	mdelay(200);
73 
74 	return 0;
75 }
76 
77 static int atc2609a_do_poweroff(const struct atc260x_pwrc *pwrc, bool restart)
78 {
79 	int ret, deep_sleep = 0;
80 	uint reg_mask, reg_val;
81 
82 	/* S4-Deep Sleep Mode is NOT available for WALL/USB power */
83 	if (!restart && !power_supply_is_system_supplied()) {
84 		deep_sleep = 1;
85 		dev_info(pwrc->dev, "Enabling S4-Deep Sleep Mode");
86 	}
87 
88 	/* Update wakeup sources */
89 	reg_val = ATC2609A_PMU_SYS_CTL0_ONOFF_LONG_WK_EN |
90 		  (restart ? ATC2609A_PMU_SYS_CTL0_RESET_WK_EN
91 			   : ATC2609A_PMU_SYS_CTL0_ONOFF_SHORT_WK_EN);
92 
93 	ret = regmap_update_bits(pwrc->regmap, ATC2609A_PMU_SYS_CTL0,
94 				 ATC2609A_PMU_SYS_CTL0_WK_ALL, reg_val);
95 	if (ret)
96 		dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);
97 
98 	/* Update power mode */
99 	reg_mask = ATC2609A_PMU_SYS_CTL3_EN_S2 | ATC2609A_PMU_SYS_CTL3_EN_S3;
100 
101 	ret = regmap_update_bits(pwrc->regmap, ATC2609A_PMU_SYS_CTL3, reg_mask,
102 				 deep_sleep ? 0 : ATC2609A_PMU_SYS_CTL3_EN_S3);
103 	if (ret) {
104 		dev_err(pwrc->dev, "failed to write SYS_CTL3: %d\n", ret);
105 		return ret;
106 	}
107 
108 	/* Trigger poweroff / restart sequence */
109 	reg_mask = restart ? ATC2609A_PMU_SYS_CTL0_RESTART_EN
110 			   : ATC2609A_PMU_SYS_CTL1_EN_S1;
111 	reg_val = restart ? ATC2609A_PMU_SYS_CTL0_RESTART_EN : 0;
112 
113 	ret = regmap_update_bits(pwrc->regmap,
114 				 restart ? ATC2609A_PMU_SYS_CTL0 : ATC2609A_PMU_SYS_CTL1,
115 				 reg_mask, reg_val);
116 	if (ret) {
117 		dev_err(pwrc->dev, "failed to write SYS_CTL%d: %d\n",
118 			restart ? 0 : 1, ret);
119 		return ret;
120 	}
121 
122 	/* Wait for trigger completion */
123 	mdelay(200);
124 
125 	return 0;
126 }
127 
128 static int atc2603c_init(const struct atc260x_pwrc *pwrc)
129 {
130 	int ret;
131 
132 	/*
133 	 * Delay transition from S2/S3 to S1 in order to avoid
134 	 * DDR init failure in Bootloader.
135 	 */
136 	ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL3,
137 				 ATC2603C_PMU_SYS_CTL3_S2S3TOS1_TIMER_EN,
138 				 ATC2603C_PMU_SYS_CTL3_S2S3TOS1_TIMER_EN);
139 	if (ret)
140 		dev_warn(pwrc->dev, "failed to write SYS_CTL3: %d\n", ret);
141 
142 	/* Set wakeup sources */
143 	ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL0,
144 				 ATC2603C_PMU_SYS_CTL0_WK_ALL,
145 				 ATC2603C_PMU_SYS_CTL0_HDSW_WK_EN |
146 				 ATC2603C_PMU_SYS_CTL0_ONOFF_LONG_WK_EN);
147 	if (ret)
148 		dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);
149 
150 	return ret;
151 }
152 
153 static int atc2609a_init(const struct atc260x_pwrc *pwrc)
154 {
155 	int ret;
156 
157 	/* Set wakeup sources */
158 	ret = regmap_update_bits(pwrc->regmap, ATC2609A_PMU_SYS_CTL0,
159 				 ATC2609A_PMU_SYS_CTL0_WK_ALL,
160 				 ATC2609A_PMU_SYS_CTL0_HDSW_WK_EN |
161 				 ATC2609A_PMU_SYS_CTL0_ONOFF_LONG_WK_EN);
162 	if (ret)
163 		dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);
164 
165 	return ret;
166 }
167 
168 static void atc260x_pwrc_pm_handler(void)
169 {
170 	atc260x_pwrc_data->do_poweroff(atc260x_pwrc_data, false);
171 
172 	WARN_ONCE(1, "Unable to power off system\n");
173 }
174 
175 static int atc260x_pwrc_restart_handler(struct notifier_block *nb,
176 					unsigned long mode, void *cmd)
177 {
178 	struct atc260x_pwrc *pwrc = container_of(nb, struct atc260x_pwrc,
179 						 restart_nb);
180 	pwrc->do_poweroff(pwrc, true);
181 
182 	return NOTIFY_DONE;
183 }
184 
185 static int atc260x_pwrc_probe(struct platform_device *pdev)
186 {
187 	struct atc260x *atc260x = dev_get_drvdata(pdev->dev.parent);
188 	struct atc260x_pwrc *priv;
189 	int ret;
190 
191 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
192 	if (!priv)
193 		return -ENOMEM;
194 
195 	priv->dev = &pdev->dev;
196 	priv->regmap = atc260x->regmap;
197 	priv->restart_nb.notifier_call = atc260x_pwrc_restart_handler;
198 	priv->restart_nb.priority = 192;
199 
200 	switch (atc260x->ic_type) {
201 	case ATC2603C:
202 		priv->do_poweroff = atc2603c_do_poweroff;
203 		ret = atc2603c_init(priv);
204 		break;
205 	case ATC2609A:
206 		priv->do_poweroff = atc2609a_do_poweroff;
207 		ret = atc2609a_init(priv);
208 		break;
209 	default:
210 		dev_err(priv->dev,
211 			"Poweroff not supported for ATC260x PMIC type: %u\n",
212 			atc260x->ic_type);
213 		return -EINVAL;
214 	}
215 
216 	if (ret)
217 		return ret;
218 
219 	platform_set_drvdata(pdev, priv);
220 
221 	if (!pm_power_off) {
222 		atc260x_pwrc_data = priv;
223 		pm_power_off = atc260x_pwrc_pm_handler;
224 	} else {
225 		dev_warn(priv->dev, "Poweroff callback already assigned\n");
226 	}
227 
228 	ret = register_restart_handler(&priv->restart_nb);
229 	if (ret)
230 		dev_err(priv->dev, "failed to register restart handler: %d\n",
231 			ret);
232 
233 	return ret;
234 }
235 
236 static int atc260x_pwrc_remove(struct platform_device *pdev)
237 {
238 	struct atc260x_pwrc *priv = platform_get_drvdata(pdev);
239 
240 	if (atc260x_pwrc_data == priv) {
241 		pm_power_off = NULL;
242 		atc260x_pwrc_data = NULL;
243 	}
244 
245 	unregister_restart_handler(&priv->restart_nb);
246 
247 	return 0;
248 }
249 
250 static struct platform_driver atc260x_pwrc_driver = {
251 	.probe = atc260x_pwrc_probe,
252 	.remove = atc260x_pwrc_remove,
253 	.driver = {
254 		.name = "atc260x-pwrc",
255 	},
256 };
257 
258 module_platform_driver(atc260x_pwrc_driver);
259 
260 MODULE_DESCRIPTION("Poweroff & reset driver for ATC260x PMICs");
261 MODULE_AUTHOR("Cristian Ciocaltea <cristian.ciocaltea@gmail.com>");
262 MODULE_LICENSE("GPL");
263