ARM: qcom: Add coincell charger driver

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>
This commit is contained in:
Tim Bird 2015-07-16 16:55:32 -07:00 committed by Greg Kroah-Hartman
parent ee2b7f60a5
commit 1f26d1c105
3 changed files with 163 additions and 0 deletions

View File

@ -271,6 +271,16 @@ config HP_ILO
To compile this driver as a module, choose M here: the
module will be called hpilo.
config QCOM_COINCELL
tristate "Qualcomm coincell charger support"
depends on MFD_SPMI_PMIC || COMPILE_TEST
help
This driver supports the coincell block found inside of
Qualcomm PMICs. The coincell charger provides a means to
charge a coincell battery or backup capacitor which is used
to maintain PMIC register and RTC state in the absence of
external power.
config SGI_GRU
tristate "SGI GRU driver"
depends on X86_UV && SMP

View File

@ -18,6 +18,7 @@ obj-$(CONFIG_LKDTM) += lkdtm.o
obj-$(CONFIG_TIFM_CORE) += tifm_core.o
obj-$(CONFIG_TIFM_7XX1) += tifm_7xx1.o
obj-$(CONFIG_PHANTOM) += phantom.o
obj-$(CONFIG_QCOM_COINCELL) += qcom-coincell.o
obj-$(CONFIG_SENSORS_BH1780) += bh1780gli.o
obj-$(CONFIG_SENSORS_BH1770) += bh1770glc.o
obj-$(CONFIG_SENSORS_APDS990X) += apds990x.o

View File

@ -0,0 +1,152 @@
/* 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, vset;
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");