pda_power: Add optional OTG transceiver and voltage regulator support

This patch allows machines to use an OTG transceiver driver instead of
supplying a custom is_usb_online callback to check USB power.
Also, in the case that the OTG transceiver handles charger control when
connected to USB, a regulator named "ac_draw" can be supplied instead of
the custom set_charge callback to control the charger when connected to
AC.

The check for (transceiver->state == OTG_STATE_B_PERIPHERAL) in
otg_is_usb_online is probably too simple, I'm just using this with a
peripheral only device and gpio_vbus + bq24022. I'm not sure which other
OTG states can supply power.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

1 files changed, 77 insertions, 12 deletions

diff --git a/drivers/power/pda_power.c b/drivers/power/pda_power.c
index b56a704409d2..a232de6a5703 100644
--- a/drivers/power/pda_power.c
+++ b/drivers/power/pda_power.c
@@ -12,11 +12,14 @@
 
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/power_supply.h>
 #include <linux/pda_power.h>
+#include <linux/regulator/consumer.h>
 #include <linux/timer.h>
 #include <linux/jiffies.h>
+#include <linux/usb/otg.h>
 
 static inline unsigned int get_irq_flags(struct resource *res)
 {
@@ -35,6 +38,11 @@ static struct timer_list supply_timer;
 static struct timer_list polling_timer;
 static int polling;
 
+#ifdef CONFIG_USB_OTG_UTILS
+static struct otg_transceiver *transceiver;
+#endif
+static struct regulator *ac_draw;
+
 enum {
         PDA_PSY_OFFLINE = 0,
         PDA_PSY_ONLINE = 1,
@@ -104,18 +112,35 @@ static void update_status(void)
 
 static void update_charger(void)
 {
-        if (!pdata->set_charge)
-                return;
-
-        if (new_ac_status > 0) {
-                dev_dbg(dev, "charger on (AC)\n");
-                pdata->set_charge(PDA_POWER_CHARGE_AC);
-        } else if (new_usb_status > 0) {
-                dev_dbg(dev, "charger on (USB)\n");
-                pdata->set_charge(PDA_POWER_CHARGE_USB);
-        } else {
-                dev_dbg(dev, "charger off\n");
-                pdata->set_charge(0);
+        static int regulator_enabled;
+        int max_uA = pdata->ac_max_uA;
+
+        if (pdata->set_charge) {
+                if (new_ac_status > 0) {
+                        dev_dbg(dev, "charger on (AC)\n");
+                        pdata->set_charge(PDA_POWER_CHARGE_AC);
+                } else if (new_usb_status > 0) {
+                        dev_dbg(dev, "charger on (USB)\n");
+                        pdata->set_charge(PDA_POWER_CHARGE_USB);
+                } else {
+                        dev_dbg(dev, "charger off\n");
+                        pdata->set_charge(0);
+                }
+        } else if (ac_draw) {
+                if (new_ac_status > 0) {
+                        regulator_set_current_limit(ac_draw, max_uA, max_uA);
+                        if (!regulator_enabled) {
+                                dev_dbg(dev, "charger on (AC)\n");
+                                regulator_enable(ac_draw);
+                                regulator_enabled = 1;
+                        }
+                } else {
+                        if (regulator_enabled) {
+                                dev_dbg(dev, "charger off\n");
+                                regulator_disable(ac_draw);
+                                regulator_enabled = 0;
+                        }
+                }
         }
 }
 
@@ -194,6 +219,13 @@ static void polling_timer_func(unsigned long unused)
                   jiffies + msecs_to_jiffies(pdata->polling_interval));
 }
 
+#ifdef CONFIG_USB_OTG_UTILS
+static int otg_is_usb_online(void)
+{
+        return (transceiver->state == OTG_STATE_B_PERIPHERAL);
+}
+#endif
+
 static int pda_power_probe(struct platform_device *pdev)
 {
         int ret = 0;
@@ -227,6 +259,9 @@ static int pda_power_probe(struct platform_device *pdev)
         if (!pdata->polling_interval)
                 pdata->polling_interval = 2000;
 
+        if (!pdata->ac_max_uA)
+                pdata->ac_max_uA = 500000;
+
         setup_timer(&charger_timer, charger_timer_func, 0);
         setup_timer(&supply_timer, supply_timer_func, 0);
 
@@ -240,6 +275,13 @@ static int pda_power_probe(struct platform_device *pdev)
                 pda_psy_usb.num_supplicants = pdata->num_supplicants;
         }
 
+        ac_draw = regulator_get(dev, "ac_draw");
+        if (IS_ERR(ac_draw)) {
+                dev_dbg(dev, "couldn't get ac_draw regulator\n");
+                ac_draw = NULL;
+                ret = PTR_ERR(ac_draw);
+        }
+
         if (pdata->is_ac_online) {
                 ret = power_supply_register(&pdev->dev, &pda_psy_ac);
                 if (ret) {
@@ -261,6 +303,13 @@ static int pda_power_probe(struct platform_device *pdev)
                 }
         }
 
+#ifdef CONFIG_USB_OTG_UTILS
+        transceiver = otg_get_transceiver();
+        if (transceiver && !pdata->is_usb_online) {
+                pdata->is_usb_online = otg_is_usb_online;
+        }
+#endif
+
         if (pdata->is_usb_online) {
                 ret = power_supply_register(&pdev->dev, &pda_psy_usb);
                 if (ret) {
@@ -300,10 +349,18 @@ usb_irq_failed:
 usb_supply_failed:
         if (pdata->is_ac_online && ac_irq)
                 free_irq(ac_irq->start, &pda_psy_ac);
+#ifdef CONFIG_USB_OTG_UTILS
+        if (transceiver)
+                otg_put_transceiver(transceiver);
+#endif
 ac_irq_failed:
         if (pdata->is_ac_online)
                 power_supply_unregister(&pda_psy_ac);
 ac_supply_failed:
+        if (ac_draw) {
+                regulator_put(ac_draw);
+                ac_draw = NULL;
+        }
         if (pdata->exit)
                 pdata->exit(dev);
 init_failed:
@@ -327,6 +384,14 @@ static int pda_power_remove(struct platform_device *pdev)
                 power_supply_unregister(&pda_psy_usb);
         if (pdata->is_ac_online)
                 power_supply_unregister(&pda_psy_ac);
+#ifdef CONFIG_USB_OTG_UTILS
+        if (transceiver)
+                otg_put_transceiver(transceiver);
+#endif
+        if (ac_draw) {
+                regulator_put(ac_draw);
+                ac_draw = NULL;
+        }
         if (pdata->exit)
                 pdata->exit(dev);