drivers/misc/pm8xxx-nfc.c

/* Copyright (c) 2010,2011 The Linux Foundation. All rights reserved.
 *
 * 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.
 *
 */
/*
 * Qualcomm PMIC8XXX NFC driver
 *
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/mfd/pm8xxx/core.h>
#include <linux/mfd/pm8xxx/nfc.h>

/* PM8XXX NFC */
#define SSBI_REG_NFC_CTRL	0x14D
#define SSBI_REG_NFC_TEST	0x14E

/* NFC_CTRL */
#define PM8XXX_NFC_SUPPORT_EN		0x80
#define PM8XXX_NFC_LDO_EN		0x40
#define PM8XXX_NFC_EN			0x20
#define PM8XXX_NFC_EXT_VDDLDO_EN	0x10
#define PM8XXX_NFC_VPH_PWR_EN		0x08
#define PM8XXX_NFC_RESERVED		0x04
#define PM8XXX_NFC_VDDLDO_LEVEL		0x03

/* NFC_TEST */
#define PM8XXX_NFC_VDDLDO_MON_EN	0x80
#define PM8XXX_NFC_ATEST_EN		0x40
#define PM8XXX_NFC_DTEST1_EN		0x20
#define PM8XXX_NFC_RESERVED2		0x18
#define PM8XXX_NFC_VDDLDO_OK_S		0x04
#define PM8XXX_NFC_MBG_EN_S		0x02
#define PM8XXX_NFC_EXT_EN_S		0x01

struct pm8xxx_nfc_device {
	struct device *dev;
	struct mutex		nfc_mutex;
#if defined(CONFIG_DEBUG_FS)
	struct dentry		*dent;
#endif
};
static struct pm8xxx_nfc_device	*nfc_dev;

/* APIs */
/*
 * pm8xxx_nfc_request - request a handle to access NFC device
 */
struct pm8xxx_nfc_device *pm8xxx_nfc_request(void)
{
	return nfc_dev;
}
EXPORT_SYMBOL(pm8xxx_nfc_request);

/*
 * pm8xxx_nfc_config - configure NFC signals
 *
 * @nfcdev: the NFC device
 * @mask: signal mask to configure
 * @flags: control flags
 */
int pm8xxx_nfc_config(struct pm8xxx_nfc_device *nfcdev, u32 mask, u32 flags)
{
	u8	nfc_ctrl, nfc_test, m, f;
	int	rc;

	if (nfcdev == NULL || IS_ERR(nfcdev) || !mask)
		return -EINVAL;

	mutex_lock(&nfcdev->nfc_mutex);

	if (!(mask & PM_NFC_CTRL_REQ))
		goto config_test;

	rc = pm8xxx_readb(nfcdev->dev->parent, SSBI_REG_NFC_CTRL, &nfc_ctrl);
	if (rc) {
		pr_err("%s: FAIL pm8xxx_readb(): rc=%d (nfc_ctrl=0x%x)\n",
		       __func__, rc, nfc_ctrl);
		goto config_done;
	}

	m = mask & 0x00ff;
	f = flags & 0x00ff;
	nfc_ctrl &= ~m;
	nfc_ctrl |= m & f;

	rc = pm8xxx_writeb(nfcdev->dev->parent, SSBI_REG_NFC_CTRL, nfc_ctrl);
	if (rc) {
		pr_err("%s: FAIL pm8xxx_writeb(): rc=%d (nfc_ctrl=0x%x)\n",
		       __func__, rc, nfc_ctrl);
		goto config_done;
	}

config_test:
	if (!(mask & PM_NFC_TEST_REQ))
		goto config_done;

	rc = pm8xxx_readb(nfcdev->dev->parent, SSBI_REG_NFC_TEST, &nfc_test);
	if (rc) {
		pr_err("%s: FAIL pm8xxx_readb(): rc=%d (nfc_test=0x%x)\n",
		       __func__, rc, nfc_test);
		goto config_done;
	}

	m = (mask >> 8) & 0x00ff;
	f = (flags >> 8) & 0x00ff;
	nfc_test &= ~m;
	nfc_test |= m & f;

	rc = pm8xxx_writeb(nfcdev->dev->parent, SSBI_REG_NFC_TEST, nfc_test);
	if (rc) {
		pr_err("%s: FAIL pm8xxx_writeb(): rc=%d (nfc_test=0x%x)\n",
		       __func__, rc, nfc_test);
		goto config_done;
	}

config_done:
	mutex_unlock(&nfcdev->nfc_mutex);
	return 0;
}
EXPORT_SYMBOL(pm8xxx_nfc_config);

/*
 * pm8xxx_nfc_get_status - get NFC status
 *
 * @nfcdev: the NFC device
 * @mask: of status mask to read
 * @status: pointer to the status variable
 */
int pm8xxx_nfc_get_status(struct pm8xxx_nfc_device *nfcdev,
			  u32 mask, u32 *status)
{
	u8	nfc_ctrl, nfc_test;
	u32	st;
	int	rc;

	if (nfcdev == NULL || IS_ERR(nfcdev) || status == NULL)
		return -EINVAL;

	st = 0;
	mutex_lock(&nfcdev->nfc_mutex);

	if (!(mask & PM_NFC_CTRL_REQ))
		goto read_test;

	rc = pm8xxx_readb(nfcdev->dev->parent, SSBI_REG_NFC_CTRL, &nfc_ctrl);
	if (rc) {
		pr_err("%s: FAIL pm8xxx_readb(): rc=%d (nfc_ctrl=0x%x)\n",
		       __func__, rc, nfc_ctrl);
		goto get_status_done;
	}

read_test:
	if (!(mask & (PM_NFC_TEST_REQ | PM_NFC_TEST_STATUS)))
		goto get_status_done;

	rc = pm8xxx_readb(nfcdev->dev->parent, SSBI_REG_NFC_TEST, &nfc_test);
	if (rc)
		pr_err("%s: FAIL pm8xxx_readb(): rc=%d (nfc_test=0x%x)\n",
		       __func__, rc, nfc_test);

get_status_done:
	st = nfc_ctrl;
	st |= nfc_test << 8;
	*status = st;

	mutex_unlock(&nfcdev->nfc_mutex);
	return 0;
}
EXPORT_SYMBOL(pm8xxx_nfc_get_status);

/*
 * pm8xxx_nfc_free - free the NFC device
 */
void pm8xxx_nfc_free(struct pm8xxx_nfc_device *nfcdev)
{
	/* Disable all signals */
	pm8xxx_nfc_config(nfcdev, PM_NFC_CTRL_REQ, 0);
}
EXPORT_SYMBOL(pm8xxx_nfc_free);

#if defined(CONFIG_DEBUG_FS)
static int pm8xxx_nfc_debug_set(void *data, u64 val)
{
	struct pm8xxx_nfc_device *nfcdev;
	u32	mask, control;
	int	rc;

	nfcdev = (struct pm8xxx_nfc_device *)data;
	control = (u32)val & 0xffff;
	mask = ((u32)val >> 16) & 0xffff;
	rc = pm8xxx_nfc_config(nfcdev, mask, control);
	if (rc)
		pr_err("%s: ERR pm8xxx_nfc_config: rc=%d, "
		       "[mask, control]=[0x%x, 0x%x]\n",
		       __func__, rc, mask, control);

	return 0;
}

static int pm8xxx_nfc_debug_get(void *data, u64 *val)
{
	struct pm8xxx_nfc_device *nfcdev;
	u32	status;
	int	rc;

	nfcdev = (struct pm8xxx_nfc_device *)data;
	rc = pm8xxx_nfc_get_status(nfcdev, (u32)-1, &status);
	if (rc)
		pr_err("%s: ERR pm8xxx_nfc_get_status: rc=%d, status=0x%x\n",
		       __func__, rc, status);

	if (val)
		*val = (u64)status;
	return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(pm8xxx_nfc_fops, pm8xxx_nfc_debug_get,
			pm8xxx_nfc_debug_set, "%llu\n");

static int pm8xxx_nfc_debug_init(struct pm8xxx_nfc_device *nfcdev)
{
	struct dentry *dent;

	dent = debugfs_create_file("pm8xxx-nfc", 0644, NULL,
				   (void *)nfcdev, &pm8xxx_nfc_fops);

	if (dent == NULL || IS_ERR(dent))
		pr_err("%s: ERR debugfs_create_file: dent=0x%x\n",
		       __func__, (unsigned)dent);

	nfcdev->dent = dent;
	return 0;
}
#endif

static int __devinit pm8xxx_nfc_probe(struct platform_device *pdev)
{
	struct pm8xxx_nfc_device	*nfcdev;

	nfcdev = kzalloc(sizeof *nfcdev, GFP_KERNEL);
	if (nfcdev == NULL) {
		pr_err("%s: kzalloc() failed.\n", __func__);
		return -ENOMEM;
	}

	mutex_init(&nfcdev->nfc_mutex);

	nfcdev->dev = &pdev->dev;
	nfc_dev = nfcdev;
	platform_set_drvdata(pdev, nfcdev);

#if defined(CONFIG_DEBUG_FS)
	pm8xxx_nfc_debug_init(nfc_dev);
#endif

	pr_notice("%s: OK\n", __func__);
	return 0;
}

static int __devexit pm8xxx_nfc_remove(struct platform_device *pdev)
{
	struct pm8xxx_nfc_device *nfcdev = platform_get_drvdata(pdev);

#if defined(CONFIG_DEBUG_FS)
	debugfs_remove(nfcdev->dent);
#endif

	platform_set_drvdata(pdev, NULL);
	kfree(nfcdev);
	return 0;
}

static struct platform_driver pm8xxx_nfc_driver = {
	.probe		= pm8xxx_nfc_probe,
	.remove		= __devexit_p(pm8xxx_nfc_remove),
	.driver		= {
		.name = PM8XXX_NFC_DEV_NAME,
		.owner = THIS_MODULE,
	},
};

static int __init pm8xxx_nfc_init(void)
{
	return platform_driver_register(&pm8xxx_nfc_driver);
}

static void __exit pm8xxx_nfc_exit(void)
{
	platform_driver_unregister(&pm8xxx_nfc_driver);
}

module_init(pm8xxx_nfc_init);
module_exit(pm8xxx_nfc_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("PM8XXX NFC driver");
MODULE_VERSION("1.0");
MODULE_ALIAS("platform:" PM8XXX_NFC_DEV_NAME);