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