1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* Copyright (c) 2013, The Linux Foundation. All rights reserved. |
3 | * Copyright (c) 2015, Sony Mobile Communications Inc. |
4 | */ |
5 | |
6 | #include <linux/kernel.h> |
7 | #include <linux/module.h> |
8 | #include <linux/slab.h> |
9 | #include <linux/of.h> |
10 | #include <linux/regmap.h> |
11 | #include <linux/platform_device.h> |
12 | |
13 | struct qcom_coincell { |
14 | struct device *dev; |
15 | struct regmap *regmap; |
16 | u32 base_addr; |
17 | }; |
18 | |
19 | #define QCOM_COINCELL_REG_RSET 0x44 |
20 | #define QCOM_COINCELL_REG_VSET 0x45 |
21 | #define QCOM_COINCELL_REG_ENABLE 0x46 |
22 | |
23 | #define QCOM_COINCELL_ENABLE BIT(7) |
24 | |
25 | static const int qcom_rset_map[] = { 2100, 1700, 1200, 800 }; |
26 | static const int qcom_vset_map[] = { 2500, 3200, 3100, 3000 }; |
27 | /* NOTE: for pm8921 and others, voltage of 2500 is 16 (10000b), not 0 */ |
28 | |
29 | /* if enable==0, rset and vset are ignored */ |
30 | static int qcom_coincell_chgr_config(struct qcom_coincell *chgr, int rset, |
31 | int vset, bool enable) |
32 | { |
33 | int i, j, rc; |
34 | |
35 | /* if disabling, just do that and skip other operations */ |
36 | if (!enable) |
37 | return regmap_write(map: chgr->regmap, |
38 | reg: chgr->base_addr + QCOM_COINCELL_REG_ENABLE, val: 0); |
39 | |
40 | /* find index for current-limiting resistor */ |
41 | for (i = 0; i < ARRAY_SIZE(qcom_rset_map); i++) |
42 | if (rset == qcom_rset_map[i]) |
43 | break; |
44 | |
45 | if (i >= ARRAY_SIZE(qcom_rset_map)) { |
46 | dev_err(chgr->dev, "invalid rset-ohms value %d\n" , rset); |
47 | return -EINVAL; |
48 | } |
49 | |
50 | /* find index for charge voltage */ |
51 | for (j = 0; j < ARRAY_SIZE(qcom_vset_map); j++) |
52 | if (vset == qcom_vset_map[j]) |
53 | break; |
54 | |
55 | if (j >= ARRAY_SIZE(qcom_vset_map)) { |
56 | dev_err(chgr->dev, "invalid vset-millivolts value %d\n" , vset); |
57 | return -EINVAL; |
58 | } |
59 | |
60 | rc = regmap_write(map: chgr->regmap, |
61 | reg: chgr->base_addr + QCOM_COINCELL_REG_RSET, val: i); |
62 | if (rc) { |
63 | /* |
64 | * This is mainly to flag a bad base_addr (reg) from dts. |
65 | * Other failures writing to the registers should be |
66 | * extremely rare, or indicative of problems that |
67 | * should be reported elsewhere (eg. spmi failure). |
68 | */ |
69 | dev_err(chgr->dev, "could not write to RSET register\n" ); |
70 | return rc; |
71 | } |
72 | |
73 | rc = regmap_write(map: chgr->regmap, |
74 | reg: chgr->base_addr + QCOM_COINCELL_REG_VSET, val: j); |
75 | if (rc) |
76 | return rc; |
77 | |
78 | /* set 'enable' register */ |
79 | return regmap_write(map: chgr->regmap, |
80 | reg: chgr->base_addr + QCOM_COINCELL_REG_ENABLE, |
81 | QCOM_COINCELL_ENABLE); |
82 | } |
83 | |
84 | static int qcom_coincell_probe(struct platform_device *pdev) |
85 | { |
86 | struct device_node *node = pdev->dev.of_node; |
87 | struct qcom_coincell chgr; |
88 | u32 rset = 0; |
89 | u32 vset = 0; |
90 | bool enable; |
91 | int rc; |
92 | |
93 | chgr.dev = &pdev->dev; |
94 | |
95 | chgr.regmap = dev_get_regmap(dev: pdev->dev.parent, NULL); |
96 | if (!chgr.regmap) { |
97 | dev_err(chgr.dev, "Unable to get regmap\n" ); |
98 | return -EINVAL; |
99 | } |
100 | |
101 | rc = of_property_read_u32(np: node, propname: "reg" , out_value: &chgr.base_addr); |
102 | if (rc) |
103 | return rc; |
104 | |
105 | enable = !of_property_read_bool(np: node, propname: "qcom,charger-disable" ); |
106 | |
107 | if (enable) { |
108 | rc = of_property_read_u32(np: node, propname: "qcom,rset-ohms" , out_value: &rset); |
109 | if (rc) { |
110 | dev_err(chgr.dev, |
111 | "can't find 'qcom,rset-ohms' in DT block" ); |
112 | return rc; |
113 | } |
114 | |
115 | rc = of_property_read_u32(np: node, propname: "qcom,vset-millivolts" , out_value: &vset); |
116 | if (rc) { |
117 | dev_err(chgr.dev, |
118 | "can't find 'qcom,vset-millivolts' in DT block" ); |
119 | return rc; |
120 | } |
121 | } |
122 | |
123 | return qcom_coincell_chgr_config(chgr: &chgr, rset, vset, enable); |
124 | } |
125 | |
126 | static const struct of_device_id qcom_coincell_match_table[] = { |
127 | { .compatible = "qcom,pm8941-coincell" , }, |
128 | {} |
129 | }; |
130 | |
131 | MODULE_DEVICE_TABLE(of, qcom_coincell_match_table); |
132 | |
133 | static struct platform_driver qcom_coincell_driver = { |
134 | .driver = { |
135 | .name = "qcom-spmi-coincell" , |
136 | .of_match_table = qcom_coincell_match_table, |
137 | }, |
138 | .probe = qcom_coincell_probe, |
139 | }; |
140 | |
141 | module_platform_driver(qcom_coincell_driver); |
142 | |
143 | MODULE_DESCRIPTION("Qualcomm PMIC coincell charger driver" ); |
144 | MODULE_LICENSE("GPL v2" ); |
145 | |