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1f26d1c105
This driver is used to configure the coincell charger found in Qualcomm PMICs. The driver allows configuring the current-limiting resistor for the charger, as well as the voltage to apply to the coincell (or capacitor) when charging. Signed-off-by: Tim Bird <tim.bird@sonymobile.com> Reviewed-by: Andy Gross <agross@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
153 lines
4.0 KiB
C
153 lines
4.0 KiB
C
/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
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* Copyright (c) 2015, Sony Mobile Communications Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include <linux/regmap.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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struct qcom_coincell {
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struct device *dev;
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struct regmap *regmap;
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u32 base_addr;
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};
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#define QCOM_COINCELL_REG_RSET 0x44
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#define QCOM_COINCELL_REG_VSET 0x45
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#define QCOM_COINCELL_REG_ENABLE 0x46
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#define QCOM_COINCELL_ENABLE BIT(7)
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static const int qcom_rset_map[] = { 2100, 1700, 1200, 800 };
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static const int qcom_vset_map[] = { 2500, 3200, 3100, 3000 };
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/* NOTE: for pm8921 and others, voltage of 2500 is 16 (10000b), not 0 */
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/* if enable==0, rset and vset are ignored */
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static int qcom_coincell_chgr_config(struct qcom_coincell *chgr, int rset,
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int vset, bool enable)
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{
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int i, j, rc;
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/* if disabling, just do that and skip other operations */
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if (!enable)
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return regmap_write(chgr->regmap,
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chgr->base_addr + QCOM_COINCELL_REG_ENABLE, 0);
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/* find index for current-limiting resistor */
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for (i = 0; i < ARRAY_SIZE(qcom_rset_map); i++)
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if (rset == qcom_rset_map[i])
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break;
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if (i >= ARRAY_SIZE(qcom_rset_map)) {
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dev_err(chgr->dev, "invalid rset-ohms value %d\n", rset);
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return -EINVAL;
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}
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/* find index for charge voltage */
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for (j = 0; j < ARRAY_SIZE(qcom_vset_map); j++)
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if (vset == qcom_vset_map[j])
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break;
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if (j >= ARRAY_SIZE(qcom_vset_map)) {
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dev_err(chgr->dev, "invalid vset-millivolts value %d\n", vset);
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return -EINVAL;
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}
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rc = regmap_write(chgr->regmap,
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chgr->base_addr + QCOM_COINCELL_REG_RSET, i);
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if (rc) {
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/*
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* This is mainly to flag a bad base_addr (reg) from dts.
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* Other failures writing to the registers should be
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* extremely rare, or indicative of problems that
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* should be reported elsewhere (eg. spmi failure).
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*/
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dev_err(chgr->dev, "could not write to RSET register\n");
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return rc;
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}
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rc = regmap_write(chgr->regmap,
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chgr->base_addr + QCOM_COINCELL_REG_VSET, j);
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if (rc)
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return rc;
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/* set 'enable' register */
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return regmap_write(chgr->regmap,
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chgr->base_addr + QCOM_COINCELL_REG_ENABLE,
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QCOM_COINCELL_ENABLE);
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}
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static int qcom_coincell_probe(struct platform_device *pdev)
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{
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struct device_node *node = pdev->dev.of_node;
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struct qcom_coincell chgr;
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u32 rset, vset;
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bool enable;
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int rc;
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chgr.dev = &pdev->dev;
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chgr.regmap = dev_get_regmap(pdev->dev.parent, NULL);
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if (!chgr.regmap) {
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dev_err(chgr.dev, "Unable to get regmap\n");
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return -EINVAL;
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}
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rc = of_property_read_u32(node, "reg", &chgr.base_addr);
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if (rc)
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return rc;
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enable = !of_property_read_bool(node, "qcom,charger-disable");
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if (enable) {
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rc = of_property_read_u32(node, "qcom,rset-ohms", &rset);
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if (rc) {
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dev_err(chgr.dev,
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"can't find 'qcom,rset-ohms' in DT block");
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return rc;
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}
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rc = of_property_read_u32(node, "qcom,vset-millivolts", &vset);
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if (rc) {
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dev_err(chgr.dev,
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"can't find 'qcom,vset-millivolts' in DT block");
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return rc;
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}
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}
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return qcom_coincell_chgr_config(&chgr, rset, vset, enable);
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}
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static const struct of_device_id qcom_coincell_match_table[] = {
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{ .compatible = "qcom,pm8941-coincell", },
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{}
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};
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MODULE_DEVICE_TABLE(of, qcom_coincell_match_table);
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static struct platform_driver qcom_coincell_driver = {
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.driver = {
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.name = "qcom-spmi-coincell",
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.of_match_table = qcom_coincell_match_table,
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},
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.probe = qcom_coincell_probe,
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};
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module_platform_driver(qcom_coincell_driver);
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MODULE_DESCRIPTION("Qualcomm PMIC coincell charger driver");
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MODULE_LICENSE("GPL v2");
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