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1// SPDX-License-Identifier: GPL-2.0-only2/* 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 0x4420#define QCOM_COINCELL_REG_VSET 0x4521#define QCOM_COINCELL_REG_ENABLE 0x4622 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 be66 * extremely rare, or indicative of problems that67 * 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");145