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1f26d1c1 TB |
1 | /* Copyright (c) 2013, The Linux Foundation. All rights reserved. |
2 | * Copyright (c) 2015, Sony Mobile Communications Inc. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 and | |
6 | * only version 2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | */ | |
13 | ||
14 | #include <linux/kernel.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/of.h> | |
18 | #include <linux/regmap.h> | |
19 | #include <linux/of_device.h> | |
20 | #include <linux/platform_device.h> | |
21 | ||
22 | struct qcom_coincell { | |
23 | struct device *dev; | |
24 | struct regmap *regmap; | |
25 | u32 base_addr; | |
26 | }; | |
27 | ||
28 | #define QCOM_COINCELL_REG_RSET 0x44 | |
29 | #define QCOM_COINCELL_REG_VSET 0x45 | |
30 | #define QCOM_COINCELL_REG_ENABLE 0x46 | |
31 | ||
32 | #define QCOM_COINCELL_ENABLE BIT(7) | |
33 | ||
34 | static const int qcom_rset_map[] = { 2100, 1700, 1200, 800 }; | |
35 | static const int qcom_vset_map[] = { 2500, 3200, 3100, 3000 }; | |
36 | /* NOTE: for pm8921 and others, voltage of 2500 is 16 (10000b), not 0 */ | |
37 | ||
38 | /* if enable==0, rset and vset are ignored */ | |
39 | static int qcom_coincell_chgr_config(struct qcom_coincell *chgr, int rset, | |
40 | int vset, bool enable) | |
41 | { | |
42 | int i, j, rc; | |
43 | ||
44 | /* if disabling, just do that and skip other operations */ | |
45 | if (!enable) | |
46 | return regmap_write(chgr->regmap, | |
47 | chgr->base_addr + QCOM_COINCELL_REG_ENABLE, 0); | |
48 | ||
49 | /* find index for current-limiting resistor */ | |
50 | for (i = 0; i < ARRAY_SIZE(qcom_rset_map); i++) | |
51 | if (rset == qcom_rset_map[i]) | |
52 | break; | |
53 | ||
54 | if (i >= ARRAY_SIZE(qcom_rset_map)) { | |
55 | dev_err(chgr->dev, "invalid rset-ohms value %d\n", rset); | |
56 | return -EINVAL; | |
57 | } | |
58 | ||
59 | /* find index for charge voltage */ | |
60 | for (j = 0; j < ARRAY_SIZE(qcom_vset_map); j++) | |
61 | if (vset == qcom_vset_map[j]) | |
62 | break; | |
63 | ||
64 | if (j >= ARRAY_SIZE(qcom_vset_map)) { | |
65 | dev_err(chgr->dev, "invalid vset-millivolts value %d\n", vset); | |
66 | return -EINVAL; | |
67 | } | |
68 | ||
69 | rc = regmap_write(chgr->regmap, | |
70 | chgr->base_addr + QCOM_COINCELL_REG_RSET, i); | |
71 | if (rc) { | |
72 | /* | |
73 | * This is mainly to flag a bad base_addr (reg) from dts. | |
74 | * Other failures writing to the registers should be | |
75 | * extremely rare, or indicative of problems that | |
76 | * should be reported elsewhere (eg. spmi failure). | |
77 | */ | |
78 | dev_err(chgr->dev, "could not write to RSET register\n"); | |
79 | return rc; | |
80 | } | |
81 | ||
82 | rc = regmap_write(chgr->regmap, | |
83 | chgr->base_addr + QCOM_COINCELL_REG_VSET, j); | |
84 | if (rc) | |
85 | return rc; | |
86 | ||
87 | /* set 'enable' register */ | |
88 | return regmap_write(chgr->regmap, | |
89 | chgr->base_addr + QCOM_COINCELL_REG_ENABLE, | |
90 | QCOM_COINCELL_ENABLE); | |
91 | } | |
92 | ||
93 | static int qcom_coincell_probe(struct platform_device *pdev) | |
94 | { | |
95 | struct device_node *node = pdev->dev.of_node; | |
96 | struct qcom_coincell chgr; | |
97 | u32 rset, vset; | |
98 | bool enable; | |
99 | int rc; | |
100 | ||
101 | chgr.dev = &pdev->dev; | |
102 | ||
103 | chgr.regmap = dev_get_regmap(pdev->dev.parent, NULL); | |
104 | if (!chgr.regmap) { | |
105 | dev_err(chgr.dev, "Unable to get regmap\n"); | |
106 | return -EINVAL; | |
107 | } | |
108 | ||
109 | rc = of_property_read_u32(node, "reg", &chgr.base_addr); | |
110 | if (rc) | |
111 | return rc; | |
112 | ||
113 | enable = !of_property_read_bool(node, "qcom,charger-disable"); | |
114 | ||
115 | if (enable) { | |
116 | rc = of_property_read_u32(node, "qcom,rset-ohms", &rset); | |
117 | if (rc) { | |
118 | dev_err(chgr.dev, | |
119 | "can't find 'qcom,rset-ohms' in DT block"); | |
120 | return rc; | |
121 | } | |
122 | ||
123 | rc = of_property_read_u32(node, "qcom,vset-millivolts", &vset); | |
124 | if (rc) { | |
125 | dev_err(chgr.dev, | |
126 | "can't find 'qcom,vset-millivolts' in DT block"); | |
127 | return rc; | |
128 | } | |
129 | } | |
130 | ||
131 | return qcom_coincell_chgr_config(&chgr, rset, vset, enable); | |
132 | } | |
133 | ||
134 | static const struct of_device_id qcom_coincell_match_table[] = { | |
135 | { .compatible = "qcom,pm8941-coincell", }, | |
136 | {} | |
137 | }; | |
138 | ||
139 | MODULE_DEVICE_TABLE(of, qcom_coincell_match_table); | |
140 | ||
141 | static struct platform_driver qcom_coincell_driver = { | |
142 | .driver = { | |
143 | .name = "qcom-spmi-coincell", | |
144 | .of_match_table = qcom_coincell_match_table, | |
145 | }, | |
146 | .probe = qcom_coincell_probe, | |
147 | }; | |
148 | ||
149 | module_platform_driver(qcom_coincell_driver); | |
150 | ||
151 | MODULE_DESCRIPTION("Qualcomm PMIC coincell charger driver"); | |
152 | MODULE_LICENSE("GPL v2"); |