Date:	Thu, 19 Aug 2010 15:09:36 +0300
From:	"Krogerus Heikki (EXT-Teleca/Helsinki)" 
	<ext-heikki.krogerus@...ia.com>
To:	linux-kernel@...r.kernel.org
Cc:	linux-omap@...r.kernel.org, dwmw2@...radead.org, cbou@...l.ru,
	felipe.balbi@...ia.com, ameya.palande@...ia.com,
	markus.lehtonen@...ia.com, roger.quadros@...ia.com
Subject: [PATCHv2 1/2] power_supply: add isp1704 charger detection driver

From: Heikki Krogerus <ext-heikki.krogerus@...ia.com>

NXP ISP1704 is Battery Charging Specification 1.0 compliant USB
transceiver. This adds a power supply driver for ISP1704 and
ISP1707 USB transceivers.

Signed-off-by: Heikki Krogerus <ext-heikki.krogerus@...ia.com>
---
 drivers/power/Kconfig           |    7 +
 drivers/power/Makefile          |    1 +
 drivers/power/isp1704_charger.c |  370 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 378 insertions(+), 0 deletions(-)
 create mode 100644 drivers/power/isp1704_charger.c

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 0734356..c2a1b8b 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -166,4 +166,11 @@ config BATTERY_INTEL_MID
 	  Say Y here to enable the battery driver on Intel MID
 	  platforms.
 
+config CHARGER_ISP1704
+	tristate "ISP1704 USB Charger Detection"
+	depends on USB_OTG_UTILS
+	help
+	  Say Y to enable support for USB Charger Detection with
+	  ISP1707/ISP1704 USB transceivers.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 10143aa..c73d381 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -37,3 +37,4 @@ obj-$(CONFIG_BATTERY_S3C_ADC)	+= s3c_adc_battery.o
 obj-$(CONFIG_CHARGER_PCF50633)	+= pcf50633-charger.o
 obj-$(CONFIG_BATTERY_JZ4740)	+= jz4740-battery.o
 obj-$(CONFIG_BATTERY_INTEL_MID)	+= intel_mid_battery.o
+obj-$(CONFIG_CHARGER_ISP1704)	+= isp1704_charger.o
diff --git a/drivers/power/isp1704_charger.c b/drivers/power/isp1704_charger.c
new file mode 100644
index 0000000..a140674
--- /dev/null
+++ b/drivers/power/isp1704_charger.c
@@ -0,0 +1,370 @@
+/*
+ * isp1704_charger.c - ISP1704 USB Charger Detection driver
+ *
+ * Copyright (C) 2010 Nokia Corporation
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/sysfs.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/delay.h>
+
+#include <linux/usb/otg.h>
+#include <linux/usb/ulpi.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+
+/* Vendor specific Power Control register */
+#define ISP1704_PWR_CTRL		0x3d
+#define ISP1704_PWR_CTRL_SWCTRL		(1 << 0)
+#define ISP1704_PWR_CTRL_DET_COMP	(1 << 1)
+#define ISP1704_PWR_CTRL_BVALID_RISE	(1 << 2)
+#define ISP1704_PWR_CTRL_BVALID_FALL	(1 << 3)
+#define ISP1704_PWR_CTRL_DP_WKPU_EN	(1 << 4)
+#define ISP1704_PWR_CTRL_VDAT_DET	(1 << 5)
+#define ISP1704_PWR_CTRL_DPVSRC_EN	(1 << 6)
+#define ISP1704_PWR_CTRL_HWDETECT	(1 << 7)
+
+#define NXP_VENDOR_ID			0x04cc
+
+static u16 isp170x_id[] = {
+	0x1704,
+	0x1707,
+};
+
+struct isp1704_charger {
+	struct device		*dev;
+	struct power_supply	psy;
+	struct otg_transceiver	*otg;
+	struct notifier_block	nb;
+	struct work_struct	work;
+
+	char			model[7];
+	unsigned		present:1;
+};
+
+/*
+ * ISP1704 detects PS/2 adapters as charger. To make sure the detected charger
+ * is actually a dedicated charger, the following steps need to be taken.
+ */
+static inline int isp1704_charger_verify(struct isp1704_charger *isp)
+{
+	int	ret = 0;
+	u8	r;
+
+	/* Reset the transceiver */
+	r = otg_io_read(isp->otg, ULPI_FUNC_CTRL);
+	r |= ULPI_FUNC_CTRL_RESET;
+	otg_io_write(isp->otg, ULPI_FUNC_CTRL, r);
+	usleep_range(1000, 2000);
+
+	/* Set normal mode */
+	r &= ~(ULPI_FUNC_CTRL_RESET | ULPI_FUNC_CTRL_OPMODE_MASK);
+	otg_io_write(isp->otg, ULPI_FUNC_CTRL, r);
+
+	/* Clear the DP and DM pull-down bits */
+	r = ULPI_OTG_CTRL_DP_PULLDOWN | ULPI_OTG_CTRL_DM_PULLDOWN;
+	otg_io_write(isp->otg, ULPI_CLR(ULPI_OTG_CTRL), r);
+
+	/* Enable strong pull-up on DP (1.5K) and reset */
+	r = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
+	otg_io_write(isp->otg, ULPI_SET(ULPI_FUNC_CTRL), r);
+	usleep_range(1000, 2000);
+
+	/* Read the line state */
+	if (!otg_io_read(isp->otg, ULPI_DEBUG)) {
+		/* Disable strong pull-up on DP (1.5K) */
+		otg_io_write(isp->otg, ULPI_CLR(ULPI_FUNC_CTRL),
+				ULPI_FUNC_CTRL_TERMSELECT);
+		return 1;
+	}
+
+	/* Is it a charger or PS/2 connection */
+
+	/* Enable weak pull-up resistor on DP */
+	otg_io_write(isp->otg, ULPI_SET(ISP1704_PWR_CTRL),
+			ISP1704_PWR_CTRL_DP_WKPU_EN);
+
+	/* Disable strong pull-up on DP (1.5K) */
+	otg_io_write(isp->otg, ULPI_CLR(ULPI_FUNC_CTRL),
+			ULPI_FUNC_CTRL_TERMSELECT);
+
+	/* Enable weak pull-down resistor on DM */
+	otg_io_write(isp->otg, ULPI_SET(ULPI_OTG_CTRL),
+			ULPI_OTG_CTRL_DM_PULLDOWN);
+
+	/* It's a charger if the line states are clear */
+	if (!(otg_io_read(isp->otg, ULPI_DEBUG)))
+		ret = 1;
+
+	/* Disable weak pull-up resistor on DP */
+	otg_io_write(isp->otg, ULPI_CLR(ISP1704_PWR_CTRL),
+			ISP1704_PWR_CTRL_DP_WKPU_EN);
+
+	return ret;
+}
+
+static inline int isp1704_charger_detect(struct isp1704_charger *isp)
+{
+	unsigned long	timeout;
+	u8		r;
+	int		ret = 0;
+
+	/* set SW control bit in PWR_CTRL register */
+	otg_io_write(isp->otg, ISP1704_PWR_CTRL,
+			ISP1704_PWR_CTRL_SWCTRL);
+
+	/* enable manual charger detection */
+	r = (ISP1704_PWR_CTRL_SWCTRL | ISP1704_PWR_CTRL_DPVSRC_EN);
+	otg_io_write(isp->otg, ULPI_SET(ISP1704_PWR_CTRL), r);
+	usleep_range(1000, 2000);
+
+	timeout = jiffies + msecs_to_jiffies(300);
+	do {
+		/* Check if there is a charger */
+		if (otg_io_read(isp->otg, ISP1704_PWR_CTRL)
+				& ISP1704_PWR_CTRL_VDAT_DET) {
+			ret = isp1704_charger_verify(isp);
+			break;
+		}
+	} while (!time_after(jiffies, timeout));
+
+	return ret;
+}
+
+static void isp1704_charger_work(struct work_struct *data)
+{
+	int			detect;
+	struct isp1704_charger	*isp =
+		container_of(data, struct isp1704_charger, work);
+
+	/*
+	 * FIXME Only supporting dedicated chargers even though isp1704 can
+	 * detect HUB and HOST chargers. If the device has already been
+	 * enumerated, the detection will break the connection.
+	 */
+	if (isp->otg->state != OTG_STATE_B_IDLE)
+		return;
+
+	/* disable data pullups */
+	if (isp->otg->gadget)
+		usb_gadget_disconnect(isp->otg->gadget);
+
+	/* detect charger */
+	detect = isp1704_charger_detect(isp);
+
+	if (detect) {
+		isp->present = detect;
+		power_supply_changed(&isp->psy);
+	}
+
+	/* enable data pullups */
+	if (isp->otg->gadget)
+		usb_gadget_connect(isp->otg->gadget);
+}
+
+static int isp1704_notifier_call(struct notifier_block *nb,
+		unsigned long event, void *unused)
+{
+	struct isp1704_charger *isp =
+		container_of(nb, struct isp1704_charger, nb);
+
+	switch (event) {
+	case USB_EVENT_VBUS:
+		schedule_work(&isp->work);
+		break;
+	case USB_EVENT_NONE:
+		if (isp->present) {
+			isp->present = 0;
+			power_supply_changed(&isp->psy);
+		}
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+
+	return NOTIFY_OK;
+}
+
+static int isp1704_charger_get_property(struct power_supply *psy,
+				enum power_supply_property psp,
+				union power_supply_propval *val)
+{
+	struct isp1704_charger *isp =
+		container_of(psy, struct isp1704_charger, psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = isp->present;
+		break;
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		val->strval = isp->model;
+		break;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		val->strval = "NXP";
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static enum power_supply_property power_props[] = {
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+static inline int isp1704_test_ulpi(struct isp1704_charger *isp)
+{
+	int vendor;
+	int product;
+	int i;
+	int ret = -ENODEV;
+
+	/* Test ULPI interface */
+	ret = otg_io_write(isp->otg, ULPI_SCRATCH, 0xaa);
+	if (ret < 0)
+		return ret;
+
+	ret = otg_io_read(isp->otg, ULPI_SCRATCH);
+	if (ret < 0)
+		return ret;
+
+	if (ret != 0xaa)
+		return -ENODEV;
+
+	/* Verify the product and vendor id matches */
+	vendor = otg_io_read(isp->otg, ULPI_VENDOR_ID_LOW);
+	vendor |= otg_io_read(isp->otg, ULPI_VENDOR_ID_HIGH) << 8;
+	if (vendor != NXP_VENDOR_ID)
+		return -ENODEV;
+
+	product = otg_io_read(isp->otg, ULPI_PRODUCT_ID_LOW);
+	product |= otg_io_read(isp->otg, ULPI_PRODUCT_ID_HIGH) << 8;
+
+	for (i = 0; i < ARRAY_SIZE(isp170x_id); i++) {
+		if (product == isp170x_id[i]) {
+			sprintf(isp->model, "isp%x", product);
+			return product;
+		}
+	}
+
+	dev_err(isp->dev, "product id %x not matching known ids", product);
+
+	return -ENODEV;
+}
+
+static int __devinit isp1704_charger_probe(struct platform_device *pdev)
+{
+	struct isp1704_charger	*isp;
+	int			ret = -ENODEV;
+
+	isp = kzalloc(sizeof *isp, GFP_KERNEL);
+	if (!isp)
+		return -ENOMEM;
+
+	isp->otg = otg_get_transceiver();
+	if (!isp->otg)
+		goto fail0;
+
+	ret = isp1704_test_ulpi(isp);
+	if (ret < 0)
+		goto fail1;
+
+	isp->dev = &pdev->dev;
+	platform_set_drvdata(pdev, isp);
+
+	isp->psy.name		= "isp1704";
+	isp->psy.type		= POWER_SUPPLY_TYPE_USB;
+	isp->psy.properties	= power_props;
+	isp->psy.num_properties	= ARRAY_SIZE(power_props);
+	isp->psy.get_property	= isp1704_charger_get_property;
+
+	ret = power_supply_register(isp->dev, &isp->psy);
+	if (ret)
+		goto fail1;
+
+	/*
+	 * REVISIT: using work in order to allow the otg notifications to be
+	 * made atomically in the future.
+	 */
+	INIT_WORK(&isp->work, isp1704_charger_work);
+
+	isp->nb.notifier_call = isp1704_notifier_call;
+
+	ret = otg_register_notifier(isp->otg, &isp->nb);
+	if (ret)
+		goto fail2;
+
+	dev_info(isp->dev, "registered with product id %s\n", isp->model);
+
+	return 0;
+fail2:
+	power_supply_unregister(&isp->psy);
+fail1:
+	otg_put_transceiver(isp->otg);
+fail0:
+	kfree(isp);
+
+	dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
+
+	return ret;
+}
+
+static int __devexit isp1704_charger_remove(struct platform_device *pdev)
+{
+	struct isp1704_charger *isp = platform_get_drvdata(pdev);
+
+	otg_unregister_notifier(isp->otg, &isp->nb);
+	power_supply_unregister(&isp->psy);
+	otg_put_transceiver(isp->otg);
+	kfree(isp);
+
+	return 0;
+}
+
+static struct platform_driver isp1704_charger_driver = {
+	.driver = {
+		.name = "isp1704_charger",
+	},
+	.probe = isp1704_charger_probe,
+	.remove = __devexit_p(isp1704_charger_remove),
+};
+
+static int __init isp1704_charger_init(void)
+{
+	return platform_driver_register(&isp1704_charger_driver);
+}
+module_init(isp1704_charger_init);
+
+static void __exit isp1704_charger_exit(void)
+{
+	platform_driver_unregister(&isp1704_charger_driver);
+}
+module_exit(isp1704_charger_exit);
+
+MODULE_ALIAS("platform:isp1704_charger");
+MODULE_AUTHOR("Nokia Corporation");
+MODULE_DESCRIPTION("ISP170x USB Charger driver");
+MODULE_LICENSE("GPL");
-- 
1.7.0.4

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