1 // SPDX-License-Identifier:     GPL-2.0+
2 /*
3  * (C) 2018 Theobroma Systems Design und Consulting GmbH
4  */
5 
6 #include <common.h>
7 #include <bitfield.h>
8 #include <errno.h>
9 #include <dm.h>
10 #include <fdtdec.h>
11 #include <i2c.h>
12 #include <asm/gpio.h>
13 #include <power/pmic.h>
14 #include <power/regulator.h>
15 
16 /**
17  * struct ic_types - definition of fan53555-family devices
18  *
19  * @die_id: Identifies the DIE_ID (lower nibble of the ID1 register)
20  * @die_rev: Identifies the DIE_REV (lower nibble of the ID2 register)
21  * @vsel_min: starting voltage (step 0) in uV
22  * @vsel_step: increment of the voltage in uV
23  *
24  * The voltage ramp (i.e. minimum voltage and step) is selected from the
25  * combination of 2 nibbles: DIE_ID and DIE_REV.
26  *
27  * See http://www.onsemi.com/pub/Collateral/FAN53555-D.pdf for details.
28  */
29 static const struct {
30 	u8 die_id;
31 	u8 die_rev;
32 	u32 vsel_min;
33 	u32 vsel_step;
34 } ic_types[] = {
35 	{ 0x0, 0x3, 600000, 10000 },  /* Option 00 */
36 	{ 0x0, 0xf, 800000, 10000 },  /* Option 13 */
37 	{ 0x0, 0xc, 600000, 12500 },  /* Option 23 */
38 	{ 0x1, 0x3, 600000, 10000 },  /* Option 01 */
39 	{ 0x3, 0x3, 600000, 10000 },  /* Option 03 */
40 	{ 0x4, 0xf, 603000, 12826 },  /* Option 04 */
41 	{ 0x5, 0x3, 600000, 10000 },  /* Option 05 */
42 	{ 0x8, 0x1, 600000, 10000 },  /* Option 08 */
43 	{ 0x8, 0xf, 600000, 10000 },  /* Option 08 */
44 	{ 0xc, 0xf, 603000, 12826 },  /* Option 09 */
45 };
46 
47 /* I2C-accessible byte-sized registers */
48 enum {
49 	/* Voltage setting */
50 	FAN53555_VSEL0 = 0x00,
51 	FAN53555_VSEL1,
52 	/* Control register */
53 	FAN53555_CONTROL,
54 	/* IC Type */
55 	FAN53555_ID1,
56 	/* IC mask version */
57 	FAN53555_ID2,
58 	/* Monitor register */
59 	FAN53555_MONITOR,
60 };
61 
62 struct fan53555_platdata {
63 	/* Voltage setting register */
64 	unsigned int vol_reg;
65 	unsigned int sleep_reg;
66 
67 };
68 
69 struct fan53555_priv {
70 	/* IC Vendor */
71 	unsigned int vendor;
72 	/* IC Type and Rev */
73 	unsigned int die_id;
74 	unsigned int die_rev;
75 	/* Voltage range and step(linear) */
76 	unsigned int vsel_min;
77 	unsigned int vsel_step;
78 	/* Voltage slew rate limiting */
79 	unsigned int slew_rate;
80 	/* Sleep voltage cache */
81 	unsigned int sleep_vol_cache;
82 };
83 
84 static int fan53555_regulator_ofdata_to_platdata(struct udevice *dev)
85 {
86 	struct fan53555_platdata *dev_pdata = dev_get_platdata(dev);
87 	struct dm_regulator_uclass_platdata *uc_pdata =
88 		dev_get_uclass_platdata(dev);
89 	u32 sleep_vsel;
90 
91 	/* This is a buck regulator */
92 	uc_pdata->type = REGULATOR_TYPE_BUCK;
93 
94 	sleep_vsel = dev_read_u32_default(dev, "fcs,suspend-voltage-selector",
95 					  FAN53555_VSEL1);
96 
97 	/*
98 	 * Depending on the device-tree settings, the 'normal mode'
99 	 * voltage is either controlled by VSEL0 or VSEL1.
100 	 */
101 	switch (sleep_vsel) {
102 	case FAN53555_VSEL0:
103 		dev_pdata->sleep_reg = FAN53555_VSEL0;
104 		dev_pdata->vol_reg = FAN53555_VSEL1;
105 		break;
106 	case FAN53555_VSEL1:
107 		dev_pdata->sleep_reg = FAN53555_VSEL1;
108 		dev_pdata->vol_reg = FAN53555_VSEL0;
109 		break;
110 	default:
111 		pr_err("%s: invalid vsel id %d\n", dev->name, sleep_vsel);
112 		return -EINVAL;
113 	}
114 
115 	return 0;
116 }
117 
118 static int fan53555_regulator_get_value(struct udevice *dev)
119 {
120 	struct fan53555_platdata *pdata = dev_get_platdata(dev);
121 	struct fan53555_priv *priv = dev_get_priv(dev);
122 	int reg;
123 	int voltage;
124 
125 	/* We only support a single voltage selector (i.e. 'normal' mode). */
126 	reg = pmic_reg_read(dev->parent, pdata->vol_reg);
127 	if (reg < 0)
128 		return reg;
129 	voltage = priv->vsel_min + (reg & 0x3f) * priv->vsel_step;
130 
131 	debug("%s: %d uV\n", __func__, voltage);
132 	return voltage;
133 }
134 
135 static int fan53555_regulator_set_value(struct udevice *dev, int uV)
136 {
137 	struct fan53555_platdata *pdata = dev_get_platdata(dev);
138 	struct fan53555_priv *priv = dev_get_priv(dev);
139 	u8 vol;
140 
141 	vol = (uV - priv->vsel_min) / priv->vsel_step;
142 	debug("%s: uV=%d; writing volume %d: %02x\n",
143 	      __func__, uV, pdata->vol_reg, vol);
144 
145 	return pmic_clrsetbits(dev, pdata->vol_reg, GENMASK(6, 0), vol);
146 }
147 
148 static int fan53555_voltages_setup(struct udevice *dev)
149 {
150 	struct fan53555_priv *priv = dev_get_priv(dev);
151 	int i;
152 
153 	/* Init voltage range and step */
154 	for (i = 0; i < ARRAY_SIZE(ic_types); ++i) {
155 		if (ic_types[i].die_id != priv->die_id)
156 			continue;
157 
158 		if (ic_types[i].die_rev != priv->die_rev)
159 			continue;
160 
161 		priv->vsel_min = ic_types[i].vsel_min;
162 		priv->vsel_step = ic_types[i].vsel_step;
163 
164 		return 0;
165 	}
166 
167 	pr_err("%s: %s: die id %d rev %d not supported!\n",
168 	       dev->name, __func__, priv->die_id, priv->die_rev);
169 	return -EINVAL;
170 }
171 
172 enum {
173 	DIE_ID_SHIFT = 0,
174 	DIE_ID_WIDTH = 4,
175 	DIE_REV_SHIFT = 0,
176 	DIE_REV_WIDTH = 4,
177 };
178 
179 static int fan53555_probe(struct udevice *dev)
180 {
181 	struct fan53555_priv *priv = dev_get_priv(dev);
182 	int ID1, ID2;
183 
184 	debug("%s\n", __func__);
185 
186 	/* read chip ID1 and ID2 (two registers, starting at ID1) */
187 	ID1 = pmic_reg_read(dev->parent, FAN53555_ID1);
188 	if (ID1 < 0)
189 		return ID1;
190 
191 	ID2 = pmic_reg_read(dev->parent, FAN53555_ID2);
192 	if (ID2 < 0)
193 		return ID2;
194 
195 	/* extract vendor, die_id and die_rev */
196 	priv->vendor = bitfield_extract(ID1, 5, 3);
197 	priv->die_id = ID1 & GENMASK(3, 0);
198 	priv->die_rev = ID2 & GENMASK(3, 0);
199 
200 	if (fan53555_voltages_setup(dev) < 0)
201 		return -ENODATA;
202 
203 	debug("%s: FAN53555 option %d rev %d detected\n",
204 	      __func__, priv->die_id, priv->die_rev);
205 
206 	return 0;
207 }
208 
209 static const struct dm_regulator_ops fan53555_regulator_ops = {
210 	.get_value	= fan53555_regulator_get_value,
211 	.set_value	= fan53555_regulator_set_value,
212 };
213 
214 U_BOOT_DRIVER(fan53555_regulator) = {
215 	.name = "fan53555_regulator",
216 	.id = UCLASS_REGULATOR,
217 	.ops = &fan53555_regulator_ops,
218 	.ofdata_to_platdata = fan53555_regulator_ofdata_to_platdata,
219 	.platdata_auto_alloc_size = sizeof(struct fan53555_platdata),
220 	.priv_auto_alloc_size = sizeof(struct fan53555_priv),
221 	.probe = fan53555_probe,
222 };
223