power_supply: Add isp1704 charger detection driver

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@nokia.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

3 files changed, 377 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 07343568a12e..c2a1b8b713f6 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 10143aaf4ee3..c73d381037a0 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 000000000000..72512185f3e2
--- /dev/null
+++ b/drivers/power/isp1704_charger.c
@@ -0,0 +1,369 @@
+/*
+ * 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");