1 /*
2  * (C) Copyright 2011-2013
3  * Texas Instruments, <www.ti.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <i2c.h>
10 #include <linux/errno.h>
11 #include <power/pmic.h>
12 #include <power/tps65218.h>
13 
14 int tps65218_reg_read(uchar dest_reg, uchar *dest_val)
15 {
16 	uchar read_val;
17 	int ret;
18 
19 	ret = i2c_read(TPS65218_CHIP_PM, dest_reg, 1, &read_val, 1);
20 	if (ret)
21 		return ret;
22 
23 	*dest_val = read_val;
24 
25 	return 0;
26 }
27 
28 /**
29  *  tps65218_reg_write() - Generic function that can write a TPS65218 PMIC
30  *			   register or bit field regardless of protection
31  *			   level.
32  *
33  *  @prot_level:	   Register password protection.  Use
34  *			   TPS65218_PROT_LEVEL_NONE,
35  *			   TPS65218_PROT_LEVEL_1 or TPS65218_PROT_LEVEL_2
36  *  @dest_reg:		   Register address to write.
37  *  @dest_val:		   Value to write.
38  *  @mask:		   Bit mask (8 bits) to be applied.  Function will only
39  *			   change bits that are set in the bit mask.
40  *
41  *  @return:		   0 for success, not 0 on failure, as per the i2c API
42  */
43 int tps65218_reg_write(uchar prot_level, uchar dest_reg, uchar dest_val,
44 		       uchar mask)
45 {
46 	uchar read_val;
47 	uchar xor_reg;
48 	int ret;
49 
50 	/*
51 	 * If we are affecting only a bit field, read dest_reg and apply the
52 	 * mask
53 	 */
54 	if (mask != TPS65218_MASK_ALL_BITS) {
55 		ret = i2c_read(TPS65218_CHIP_PM, dest_reg, 1, &read_val, 1);
56 		if (ret)
57 			return ret;
58 		read_val &= (~mask);
59 		read_val |= (dest_val & mask);
60 		dest_val = read_val;
61 	}
62 
63 	if (prot_level > 0) {
64 		xor_reg = dest_reg ^ TPS65218_PASSWORD_UNLOCK;
65 		ret = i2c_write(TPS65218_CHIP_PM, TPS65218_PASSWORD, 1,
66 				&xor_reg, 1);
67 		if (ret)
68 			return ret;
69 	}
70 
71 	ret = i2c_write(TPS65218_CHIP_PM, dest_reg, 1, &dest_val, 1);
72 	if (ret)
73 		return ret;
74 
75 	if (prot_level == TPS65218_PROT_LEVEL_2) {
76 		ret = i2c_write(TPS65218_CHIP_PM, TPS65218_PASSWORD, 1,
77 				&xor_reg, 1);
78 		if (ret)
79 			return ret;
80 
81 		ret = i2c_write(TPS65218_CHIP_PM, dest_reg, 1, &dest_val, 1);
82 		if (ret)
83 			return ret;
84 	}
85 
86 	return 0;
87 }
88 
89 /**
90  * tps65218_voltage_update() - Function to change a voltage level, as this
91  *			       is a multi-step process.
92  * @dc_cntrl_reg:	       DC voltage control register to change.
93  * @volt_sel:		       New value for the voltage register
94  * @return:		       0 for success, not 0 on failure.
95  */
96 int tps65218_voltage_update(uchar dc_cntrl_reg, uchar volt_sel)
97 {
98 	if ((dc_cntrl_reg != TPS65218_DCDC1) &&
99 	    (dc_cntrl_reg != TPS65218_DCDC2))
100 		return 1;
101 
102 	/* set voltage level */
103 	if (tps65218_reg_write(TPS65218_PROT_LEVEL_2, dc_cntrl_reg, volt_sel,
104 			       TPS65218_MASK_ALL_BITS))
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  */
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  */
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 
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