[mirror_ubuntu-zesty-kernel.git] / drivers / misc / qcom-coincell.c

/* 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");
Commit	Line	Data
1f26d1c1 TB	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
	22	struct 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
	34	static const int qcom_rset_map[] = { 2100, 1700, 1200, 800 };
	35	static 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 */
	39	static 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
93	static int qcom_coincell_probe(struct platform_device *pdev)
94	{
95	struct device_node *node = pdev->dev.of_node;
96	struct qcom_coincell chgr;
66b58edf DC	97	u32 rset = 0;
66b58edf DC	98	u32 vset = 0;
1f26d1c1 TB	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
	135	static const struct of_device_id qcom_coincell_match_table[] = {
	136	{ .compatible = "qcom,pm8941-coincell", },
	137	{}
	138	};
	139
	140	MODULE_DEVICE_TABLE(of, qcom_coincell_match_table);
	141
	142	static 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
	150	module_platform_driver(qcom_coincell_driver);
	151
	152	MODULE_DESCRIPTION("Qualcomm PMIC coincell charger driver");
	153	MODULE_LICENSE("GPL v2");