1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2015 Google, Inc
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <errno.h>
9 #include <power/pmic.h>
10 #include <power/regulator.h>
11 #include <power/tps65090.h>
12 
tps65090_fet_probe(struct udevice * dev)13 static int tps65090_fet_probe(struct udevice *dev)
14 {
15 	struct dm_regulator_uclass_platdata *uc_pdata;
16 
17 	uc_pdata = dev_get_uclass_platdata(dev);
18 
19 	uc_pdata->type = REGULATOR_TYPE_OTHER;
20 	uc_pdata->mode_count = 0;
21 
22 	return 0;
23 }
24 
tps65090_fet_get_enable(struct udevice * dev)25 static int tps65090_fet_get_enable(struct udevice *dev)
26 {
27 	struct udevice *pmic = dev_get_parent(dev);
28 	int ret, fet_id;
29 
30 	fet_id = dev->driver_data;
31 	debug("%s: fet_id=%d\n", __func__, fet_id);
32 
33 	ret = pmic_reg_read(pmic, REG_FET_BASE + fet_id);
34 	if (ret < 0)
35 		return ret;
36 
37 	return ret & FET_CTRL_ENFET;
38 }
39 
40 /**
41  * Set the power state for a FET
42  *
43  * @param pmic		pmic structure for the tps65090
44  * @param fet_id	FET number to set (1..MAX_FET_NUM)
45  * @param set		1 to power on FET, 0 to power off
46  * @return -EIO if we got a comms error, -EAGAIN if the FET failed to
47  * change state. If all is ok, returns 0.
48  */
tps65090_fet_set(struct udevice * pmic,int fet_id,bool set)49 static int tps65090_fet_set(struct udevice *pmic, int fet_id, bool set)
50 {
51 	int retry;
52 	u32 value;
53 	int ret;
54 
55 	value = FET_CTRL_ADENFET | FET_CTRL_WAIT;
56 	if (set)
57 		value |= FET_CTRL_ENFET;
58 
59 	if (pmic_reg_write(pmic, REG_FET_BASE + fet_id, value))
60 		return -EIO;
61 
62 	/* Try reading until we get a result */
63 	for (retry = 0; retry < MAX_CTRL_READ_TRIES; retry++) {
64 		ret = pmic_reg_read(pmic, REG_FET_BASE + fet_id);
65 		if (ret < 0)
66 			return ret;
67 
68 		/* Check that the FET went into the expected state */
69 		debug("%s: flags=%x\n", __func__, ret);
70 		if (!!(ret & FET_CTRL_PGFET) == set)
71 			return 0;
72 
73 		/* If we got a timeout, there is no point in waiting longer */
74 		if (ret & FET_CTRL_TOFET)
75 			break;
76 
77 		mdelay(1);
78 	}
79 
80 	debug("FET %d: Power good should have set to %d but reg=%#02x\n",
81 	      fet_id, set, ret);
82 	return -EAGAIN;
83 }
84 
tps65090_fet_set_enable(struct udevice * dev,bool enable)85 static int tps65090_fet_set_enable(struct udevice *dev, bool enable)
86 {
87 	struct udevice *pmic = dev_get_parent(dev);
88 	int ret, fet_id;
89 	ulong start;
90 	int loops;
91 
92 	fet_id = dev->driver_data;
93 	debug("%s: fet_id=%d, enable=%d\n", __func__, fet_id, enable);
94 
95 	start = get_timer(0);
96 	for (loops = 0;; loops++) {
97 		ret = tps65090_fet_set(pmic, fet_id, enable);
98 		if (!ret)
99 			break;
100 
101 		if (get_timer(start) > 100)
102 			break;
103 
104 		/* Turn it off and try again until we time out */
105 		tps65090_fet_set(pmic, fet_id, false);
106 	}
107 
108 	if (ret)
109 		debug("%s: FET%d failed to power on: time=%lums, loops=%d\n",
110 		      __func__, fet_id, get_timer(start), loops);
111 	else if (loops)
112 		debug("%s: FET%d powered on after %lums, loops=%d\n",
113 		      __func__, fet_id, get_timer(start), loops);
114 
115 	/*
116 	 * Unfortunately there are some conditions where the power-good bit
117 	 * will be 0, but the FET still comes up. One such case occurs with
118 	 * the LCD backlight on snow. We'll just return 0 here and assume
119 	 * that the FET will eventually come up.
120 	 */
121 	if (ret == -EAGAIN)
122 		ret = 0;
123 
124 	return ret;
125 }
126 
127 static const struct dm_regulator_ops tps65090_fet_ops = {
128 	.get_enable = tps65090_fet_get_enable,
129 	.set_enable = tps65090_fet_set_enable,
130 };
131 
132 U_BOOT_DRIVER(tps65090_fet) = {
133 	.name = TPS65090_FET_DRIVER,
134 	.id = UCLASS_REGULATOR,
135 	.ops = &tps65090_fet_ops,
136 	.probe = tps65090_fet_probe,
137 };
138