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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2011-2013
4  * Texas Instruments, <www.ti.com>
5  */
6 
7 #include <common.h>
8 #include <i2c.h>
9 #include <linux/errno.h>
10 #include <power/pmic.h>
11 #include <power/tps65218.h>
12 
tps65218_reg_read(uchar dest_reg,uchar * dest_val)13 int tps65218_reg_read(uchar dest_reg, uchar *dest_val)
14 {
15 	uchar read_val;
16 	int ret;
17 
18 	ret = i2c_read(TPS65218_CHIP_PM, dest_reg, 1, &read_val, 1);
19 	if (ret)
20 		return ret;
21 
22 	*dest_val = read_val;
23 
24 	return 0;
25 }
26 
27 /**
28  *  tps65218_reg_write() - Generic function that can write a TPS65218 PMIC
29  *			   register or bit field regardless of protection
30  *			   level.
31  *
32  *  @prot_level:	   Register password protection.  Use
33  *			   TPS65218_PROT_LEVEL_NONE,
34  *			   TPS65218_PROT_LEVEL_1 or TPS65218_PROT_LEVEL_2
35  *  @dest_reg:		   Register address to write.
36  *  @dest_val:		   Value to write.
37  *  @mask:		   Bit mask (8 bits) to be applied.  Function will only
38  *			   change bits that are set in the bit mask.
39  *
40  *  @return:		   0 for success, not 0 on failure, as per the i2c API
41  */
tps65218_reg_write(uchar prot_level,uchar dest_reg,uchar dest_val,uchar mask)42 int tps65218_reg_write(uchar prot_level, uchar dest_reg, uchar dest_val,
43 		       uchar mask)
44 {
45 	uchar read_val;
46 	uchar xor_reg;
47 	int ret;
48 
49 	/*
50 	 * If we are affecting only a bit field, read dest_reg and apply the
51 	 * mask
52 	 */
53 	if (mask != TPS65218_MASK_ALL_BITS) {
54 		ret = i2c_read(TPS65218_CHIP_PM, dest_reg, 1, &read_val, 1);
55 		if (ret)
56 			return ret;
57 		read_val &= (~mask);
58 		read_val |= (dest_val & mask);
59 		dest_val = read_val;
60 	}
61 
62 	if (prot_level > 0) {
63 		xor_reg = dest_reg ^ TPS65218_PASSWORD_UNLOCK;
64 		ret = i2c_write(TPS65218_CHIP_PM, TPS65218_PASSWORD, 1,
65 				&xor_reg, 1);
66 		if (ret)
67 			return ret;
68 	}
69 
70 	ret = i2c_write(TPS65218_CHIP_PM, dest_reg, 1, &dest_val, 1);
71 	if (ret)
72 		return ret;
73 
74 	if (prot_level == TPS65218_PROT_LEVEL_2) {
75 		ret = i2c_write(TPS65218_CHIP_PM, TPS65218_PASSWORD, 1,
76 				&xor_reg, 1);
77 		if (ret)
78 			return ret;
79 
80 		ret = i2c_write(TPS65218_CHIP_PM, dest_reg, 1, &dest_val, 1);
81 		if (ret)
82 			return ret;
83 	}
84 
85 	return 0;
86 }
87 
88 /**
89  * tps65218_voltage_update() - Function to change a voltage level, as this
90  *			       is a multi-step process.
91  * @dc_cntrl_reg:	       DC voltage control register to change.
92  * @volt_sel:		       New value for the voltage register
93  * @return:		       0 for success, not 0 on failure.
94  */
tps65218_voltage_update(uchar dc_cntrl_reg,uchar volt_sel)95 int tps65218_voltage_update(uchar dc_cntrl_reg, uchar volt_sel)
96 {
97 	if ((dc_cntrl_reg != TPS65218_DCDC1) &&
98 	    (dc_cntrl_reg != TPS65218_DCDC2) &&
99 	    (dc_cntrl_reg != TPS65218_DCDC3))
100 		return 1;
101 
102 	/* set voltage level */
103 	if (tps65218_reg_write(TPS65218_PROT_LEVEL_2, dc_cntrl_reg, volt_sel,
104 			       TPS65218_DCDC_VSEL_MASK))
105 		return 1;
106 
107 	/* set GO bit to initiate voltage transition */
108 	if (tps65218_reg_write(TPS65218_PROT_LEVEL_2, TPS65218_SLEW,
109 			       TPS65218_DCDC_GO, TPS65218_DCDC_GO))
110 		return 1;
111 
112 	return 0;
113 }
114 
115 /**
116  * tps65218_toggle_fseal() - Perform the sequence that toggles the FSEAL bit.
117  *
118  * @return:		     0 on success, -EBADE if the sequence was broken
119  */
tps65218_toggle_fseal(void)120 int tps65218_toggle_fseal(void)
121 {
122 	if (tps65218_reg_write(TPS65218_PROT_LEVEL_NONE, TPS65218_PASSWORD,
123 			       0xb1, TPS65218_MASK_ALL_BITS))
124 		return -EBADE;
125 
126 	if (tps65218_reg_write(TPS65218_PROT_LEVEL_NONE, TPS65218_PASSWORD,
127 			       0xfe, TPS65218_MASK_ALL_BITS))
128 		return -EBADE;
129 
130 	if (tps65218_reg_write(TPS65218_PROT_LEVEL_NONE, TPS65218_PASSWORD,
131 			       0xa3, TPS65218_MASK_ALL_BITS))
132 		return -EBADE;
133 
134 	return 0;
135 }
136 
137 /**
138  * tps65218_lock_fseal() - Perform the sequence that locks the FSEAL bit to 1.
139  *
140  * The FSEAL bit prevents the PMIC from turning off DCDC5 and DCDC6. It can be
141  * toggled at most 3 times: 0->1, 1->0, and finally 0->1. After the third switch
142  * its value is locked and can only be reset by powering off the PMIC entirely.
143  *
144  * @return:		   0 on success, -EBADE if the sequence was broken
145  */
tps65218_lock_fseal(void)146 int tps65218_lock_fseal(void)
147 {
148 	int i;
149 
150 	for (i = 0; i < 3; i++)
151 		if (tps65218_toggle_fseal())
152 			return -EBADE;
153 
154 	return 0;
155 }
156 
power_tps65218_init(unsigned char bus)157 int power_tps65218_init(unsigned char bus)
158 {
159 	static const char name[] = "TPS65218_PMIC";
160 	struct pmic *p = pmic_alloc();
161 
162 	if (!p) {
163 		printf("%s: POWER allocation error!\n", __func__);
164 		return -ENOMEM;
165 	}
166 
167 	p->name = name;
168 	p->interface = PMIC_I2C;
169 	p->number_of_regs = TPS65218_PMIC_NUM_OF_REGS;
170 	p->hw.i2c.addr = TPS65218_CHIP_PM;
171 	p->hw.i2c.tx_num = 1;
172 	p->bus = bus;
173 
174 	return 0;
175 }
176