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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
13struct 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
25static const int qcom_rset_map[] = { 2100, 1700, 1200, 800 };
26static 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 */
30static 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(chgr->regmap,
38 chgr->base_addr + QCOM_COINCELL_REG_ENABLE, 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(chgr->regmap,
61 chgr->base_addr + QCOM_COINCELL_REG_RSET, 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(chgr->regmap,
74 chgr->base_addr + QCOM_COINCELL_REG_VSET, j);
75 if (rc)
76 return rc;
77
78 /* set 'enable' register */
79 return regmap_write(chgr->regmap,
80 chgr->base_addr + QCOM_COINCELL_REG_ENABLE,
81 QCOM_COINCELL_ENABLE);
82}
83
84static 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(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(node, "reg", &chgr.base_addr);
102 if (rc)
103 return rc;
104
105 enable = !of_property_read_bool(node, "qcom,charger-disable");
106
107 if (enable) {
108 rc = of_property_read_u32(node, "qcom,rset-ohms", &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(node, "qcom,vset-millivolts", &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, rset, vset, enable);
124}
125
126static const struct of_device_id qcom_coincell_match_table[] = {
127 { .compatible = "qcom,pm8941-coincell", },
128 {}
129};
130
131MODULE_DEVICE_TABLE(of, qcom_coincell_match_table);
132
133static 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
141module_platform_driver(qcom_coincell_driver);
142
143MODULE_DESCRIPTION("Qualcomm PMIC coincell charger driver");
144MODULE_LICENSE("GPL v2");
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
22struct 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
34static const int qcom_rset_map[] = { 2100, 1700, 1200, 800 };
35static 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 */
39static 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
93static 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 = 0;
98 u32 vset = 0;
99 bool enable;
100 int rc;
101
102 chgr.dev = &pdev->dev;
103
104 chgr.regmap = dev_get_regmap(pdev->dev.parent, NULL);
105 if (!chgr.regmap) {
106 dev_err(chgr.dev, "Unable to get regmap\n");
107 return -EINVAL;
108 }
109
110 rc = of_property_read_u32(node, "reg", &chgr.base_addr);
111 if (rc)
112 return rc;
113
114 enable = !of_property_read_bool(node, "qcom,charger-disable");
115
116 if (enable) {
117 rc = of_property_read_u32(node, "qcom,rset-ohms", &rset);
118 if (rc) {
119 dev_err(chgr.dev,
120 "can't find 'qcom,rset-ohms' in DT block");
121 return rc;
122 }
123
124 rc = of_property_read_u32(node, "qcom,vset-millivolts", &vset);
125 if (rc) {
126 dev_err(chgr.dev,
127 "can't find 'qcom,vset-millivolts' in DT block");
128 return rc;
129 }
130 }
131
132 return qcom_coincell_chgr_config(&chgr, rset, vset, enable);
133}
134
135static const struct of_device_id qcom_coincell_match_table[] = {
136 { .compatible = "qcom,pm8941-coincell", },
137 {}
138};
139
140MODULE_DEVICE_TABLE(of, qcom_coincell_match_table);
141
142static struct platform_driver qcom_coincell_driver = {
143 .driver = {
144 .name = "qcom-spmi-coincell",
145 .of_match_table = qcom_coincell_match_table,
146 },
147 .probe = qcom_coincell_probe,
148};
149
150module_platform_driver(qcom_coincell_driver);
151
152MODULE_DESCRIPTION("Qualcomm PMIC coincell charger driver");
153MODULE_LICENSE("GPL v2");