power: max77660: implement battery charger and extcon

MAX77660 is a pmic for smartphones and tablets which supports
battery charging feature. It also detect the presence of USB HOST
cable. Implement the notification mechanism for USB Host cable
connection through extcon framework.

Change-Id: Ia75662e865ca34ec40f296d49de6573cc0b6a928
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/194458
Reviewed-by: Automatic_Commit_Validation_User

1 files changed, 225 insertions, 0 deletions

diff --git a/drivers/power/max77660-charger-extcon.c b/drivers/power/max77660-charger-extcon.c
new file mode 100644
index 000000000000..b3924e773eec
--- /dev/null
+++ b/drivers/power/max77660-charger-extcon.c
@@ -0,0 +1,225 @@
+/*
+ * max77660-charger-extcon.c -- MAXIM MAX77660 VBUS detection.
+ *
+ * Copyright (c) 2013, NVIDIA Corporation.
+ *
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
+ * whether express or implied; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307, USA
+ */
+#include <linux/module.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/pm.h>
+#include <linux/extcon.h>
+#include <linux/mfd/max77660/max77660-core.h>
+
+struct max77660_chg_extcon {
+	struct device		*dev;
+	struct device		*parent;
+	struct extcon_dev	*edev;
+	int			irq;
+};
+
+const char *max77660_excon_cable[] = {
+	[0] = "USB-Host",
+	NULL,
+};
+
+static int max77660_chg_extcon_cable_update(
+		struct max77660_chg_extcon *chg_extcon)
+{
+	int ret;
+	u8 status;
+
+	ret = max77660_reg_read(chg_extcon->parent, MAX77660_CHG_SLAVE,
+			MAX77660_CHARGER_CHGSTAT, &status);
+	if (ret < 0) {
+		dev_err(chg_extcon->dev, "CHSTAT read failed: %d\n", ret);
+		return ret;
+	}
+	if (status & MAX77660_CHG_CHGINT_DC_UVP)
+		extcon_set_cable_state(chg_extcon->edev, "USB-Host", false);
+	else
+		extcon_set_cable_state(chg_extcon->edev, "USB-Host", true);
+
+	dev_info(chg_extcon->dev, "VBUS %s status: 0x%02x\n",
+		(status & MAX77660_CHG_CHGINT_DC_UVP) ? "Invalid" : "Valid",
+		status);
+
+	return 0;
+}
+
+static irqreturn_t max77660_chg_extcon_irq(int irq, void *data)
+{
+	struct max77660_chg_extcon *chg_extcon = data;
+	u8 status;
+	int ret;
+
+	ret = max77660_reg_read(chg_extcon->parent, MAX77660_CHG_SLAVE,
+			MAX77660_CHARGER_CHGINT, &status);
+	if (ret < 0) {
+		dev_err(chg_extcon->dev, "CHGSTAT read failed: %d\n", ret);
+		goto out;
+	}
+
+	if (status & MAX77660_CHG_CHGINT_DC_UVP)
+		max77660_chg_extcon_cable_update(chg_extcon);
+	else
+		dev_err(chg_extcon->dev, "CHG-IRQ for unknown reason, 0x%02x\n",
+			status);
+out:
+	return IRQ_HANDLED;
+}
+
+static int __devinit max77660_chg_extcon_probe(struct platform_device *pdev)
+{
+	struct max77660_chg_extcon *chg_extcon;
+	struct max77660_platform_data *pdata;
+	struct extcon_dev *edev;
+	int ret;
+
+	pdata = dev_get_platdata(pdev->dev.parent);
+	if (!pdata) {
+		dev_err(&pdev->dev, "No platform data\n");
+		return -ENODEV;
+	}
+
+	chg_extcon = devm_kzalloc(&pdev->dev, sizeof(*chg_extcon), GFP_KERNEL);
+	if (!chg_extcon) {
+		dev_err(&pdev->dev, "Memory allocation failed for chg_extcon\n");
+		return -ENOMEM;
+	}
+
+	edev = devm_kzalloc(&pdev->dev, sizeof(*edev), GFP_KERNEL);
+	if (!edev) {
+		dev_err(&pdev->dev, "Memory allocation failed for edev\n");
+		return -ENOMEM;
+	}
+	chg_extcon->edev = edev;
+	chg_extcon->edev->name = dev_name(&pdev->dev);
+	chg_extcon->edev->supported_cable = max77660_excon_cable;
+
+	chg_extcon->dev = &pdev->dev;
+	chg_extcon->parent = pdev->dev.parent;
+	dev_set_drvdata(&pdev->dev, chg_extcon);
+
+	chg_extcon->irq = platform_get_irq(pdev, 0);
+
+	ret = extcon_dev_register(chg_extcon->edev, NULL);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to register extcon device\n");
+		return ret;
+	}
+
+	/* Set initial state */
+	ret = max77660_chg_extcon_cable_update(chg_extcon);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Cable init failed: %d\n", ret);
+		goto out;
+	}
+
+	ret = request_threaded_irq(chg_extcon->irq, NULL,
+		max77660_chg_extcon_irq,
+		IRQF_ONESHOT | IRQF_EARLY_RESUME, dev_name(chg_extcon->dev),
+		chg_extcon);
+	if (ret < 0) {
+		dev_err(chg_extcon->dev,
+			"request irq %d failed: %dn", chg_extcon->irq, ret);
+		goto out;
+	}
+
+	ret = max77660_reg_clr_bits(chg_extcon->parent, MAX77660_CHG_SLAVE,
+			MAX77660_CHARGER_CHGINTM, MAX77660_CHG_CHGINT_DC_UVP);
+	if (ret < 0) {
+		dev_err(chg_extcon->dev, "CHGINTM update failed: %d\n", ret);
+		goto out_irq_free;
+	}
+
+
+	device_set_wakeup_capable(&pdev->dev, 1);
+	return 0;
+
+out_irq_free:
+	free_irq(chg_extcon->irq, chg_extcon);
+out:
+	extcon_dev_unregister(chg_extcon->edev);
+	return ret;
+}
+
+static int __devexit max77660_chg_extcon_remove(struct platform_device *pdev)
+{
+	struct max77660_chg_extcon *chg_extcon = dev_get_drvdata(&pdev->dev);
+
+	extcon_dev_unregister(chg_extcon->edev);
+	free_irq(chg_extcon->irq, chg_extcon);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int max77660_chg_extcon_suspend(struct device *dev)
+{
+	struct max77660_chg_extcon *chg_extcon = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(chg_extcon->irq);
+	return 0;
+}
+
+static int max77660_chg_extcon_resume(struct device *dev)
+{
+	struct max77660_chg_extcon *chg_extcon = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(chg_extcon->irq);
+	return 0;
+};
+#endif
+
+static const struct dev_pm_ops max77660_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(max77660_chg_extcon_suspend,
+				max77660_chg_extcon_resume)
+};
+
+static struct platform_driver max77660_chg_extcon_driver = {
+	.probe = max77660_chg_extcon_probe,
+	.remove = __devexit_p(max77660_chg_extcon_remove),
+	.driver = {
+		.name = "max77660-charger-extcon",
+		.owner = THIS_MODULE,
+		.pm = &max77660_pm_ops,
+	},
+};
+
+static int __init max77660_chg_extcon_driver_init(void)
+{
+	return platform_driver_register(&max77660_chg_extcon_driver);
+}
+subsys_initcall_sync(max77660_chg_extcon_driver_init);
+
+static void __exit max77660_chg_extcon_driver_exit(void)
+{
+	platform_driver_unregister(&max77660_chg_extcon_driver);
+}
+module_exit(max77660_chg_extcon_driver_exit);
+
+MODULE_DESCRIPTION("max77660 charger-extcon driver");
+MODULE_AUTHOR("Laxman Dewangan<ldewangan@nvidia.com>");
+MODULE_ALIAS("platform:max77660-charger-extcon");
+MODULE_LICENSE("GPL v2");