wm831x: Factor out WM831x backup battery charger

The backup battery on WM831x is a separate IP block to the main PMU
and is largely unrelated to the main supply functionality. Factor it
out into a separate driver in order to reflect this and better support
future hardware versions.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

4 files changed, 244 insertions, 141 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index cea6cef27e8..783e9b790b0 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -29,6 +29,13 @@ config APM_POWER
           Say Y here to enable support APM status emulation using
           battery class devices.
 
+config WM831X_BACKUP
+        tristate "WM831X backup battery charger support"
+        depends on MFD_WM831X
+        help
+          Say Y here to enable support for the backup battery charger
+          in the Wolfson Microelectronics WM831x PMICs.
+
 config WM831X_POWER
         tristate "WM831X PMU support"
         depends on MFD_WM831X
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index b96f29d91c2..d1406b9f02f 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_POWER_SUPPLY)	+= power_supply.o
 
 obj-$(CONFIG_PDA_POWER)         += pda_power.o
 obj-$(CONFIG_APM_POWER)         += apm_power.o
+obj-$(CONFIG_WM831X_BACKUP)     += wm831x_backup.o
 obj-$(CONFIG_WM831X_POWER)      += wm831x_power.o
 obj-$(CONFIG_WM8350_POWER)      += wm8350_power.o
 
diff --git a/drivers/power/wm831x_backup.c b/drivers/power/wm831x_backup.c
new file mode 100644
index 00000000000..f181076a408
--- /dev/null
+++ b/drivers/power/wm831x_backup.c
@@ -0,0 +1,233 @@
+/*
+ * Backup battery driver for Wolfson Microelectronics wm831x PMICs
+ *
+ * Copyright 2009 Wolfson Microelectronics PLC.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+
+#include <linux/mfd/wm831x/core.h>
+#include <linux/mfd/wm831x/auxadc.h>
+#include <linux/mfd/wm831x/pmu.h>
+#include <linux/mfd/wm831x/pdata.h>
+
+struct wm831x_backup {
+        struct wm831x *wm831x;
+        struct power_supply backup;
+};
+
+static int wm831x_backup_read_voltage(struct wm831x *wm831x,
+                                     enum wm831x_auxadc src,
+                                     union power_supply_propval *val)
+{
+        int ret;
+
+        ret = wm831x_auxadc_read_uv(wm831x, src);
+        if (ret >= 0)
+                val->intval = ret;
+
+        return ret;
+}
+
+/*********************************************************************
+ *              Backup supply properties
+ *********************************************************************/
+
+static void wm831x_config_backup(struct wm831x *wm831x)
+{
+        struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data;
+        struct wm831x_backup_pdata *pdata;
+        int ret, reg;
+
+        if (!wm831x_pdata || !wm831x_pdata->backup) {
+                dev_warn(wm831x->dev,
+                         "No backup battery charger configuration\n");
+                return;
+        }
+
+        pdata = wm831x_pdata->backup;
+
+        reg = 0;
+
+        if (pdata->charger_enable)
+                reg |= WM831X_BKUP_CHG_ENA | WM831X_BKUP_BATT_DET_ENA;
+        if (pdata->no_constant_voltage)
+                reg |= WM831X_BKUP_CHG_MODE;
+
+        switch (pdata->vlim) {
+        case 2500:
+                break;
+        case 3100:
+                reg |= WM831X_BKUP_CHG_VLIM;
+                break;
+        default:
+                dev_err(wm831x->dev, "Invalid backup voltage limit %dmV\n",
+                        pdata->vlim);
+        }
+
+        switch (pdata->ilim) {
+        case 100:
+                break;
+        case 200:
+                reg |= 1;
+                break;
+        case 300:
+                reg |= 2;
+                break;
+        case 400:
+                reg |= 3;
+                break;
+        default:
+                dev_err(wm831x->dev, "Invalid backup current limit %duA\n",
+                        pdata->ilim);
+        }
+
+        ret = wm831x_reg_unlock(wm831x);
+        if (ret != 0) {
+                dev_err(wm831x->dev, "Failed to unlock registers: %d\n", ret);
+                return;
+        }
+
+        ret = wm831x_set_bits(wm831x, WM831X_BACKUP_CHARGER_CONTROL,
+                              WM831X_BKUP_CHG_ENA_MASK |
+                              WM831X_BKUP_CHG_MODE_MASK |
+                              WM831X_BKUP_BATT_DET_ENA_MASK |
+                              WM831X_BKUP_CHG_VLIM_MASK |
+                              WM831X_BKUP_CHG_ILIM_MASK,
+                              reg);
+        if (ret != 0)
+                dev_err(wm831x->dev,
+                        "Failed to set backup charger config: %d\n", ret);
+
+        wm831x_reg_lock(wm831x);
+}
+
+static int wm831x_backup_get_prop(struct power_supply *psy,
+                                  enum power_supply_property psp,
+                                  union power_supply_propval *val)
+{
+        struct wm831x_backup *devdata = dev_get_drvdata(psy->dev->parent);
+        struct wm831x *wm831x = devdata->wm831x;
+        int ret = 0;
+
+        ret = wm831x_reg_read(wm831x, WM831X_BACKUP_CHARGER_CONTROL);
+        if (ret < 0)
+                return ret;
+
+        switch (psp) {
+        case POWER_SUPPLY_PROP_STATUS:
+                if (ret & WM831X_BKUP_CHG_STS)
+                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
+                else
+                        val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+                break;
+
+        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+                ret = wm831x_backup_read_voltage(wm831x, WM831X_AUX_BKUP_BATT,
+                                                val);
+                break;
+
+        case POWER_SUPPLY_PROP_PRESENT:
+                if (ret & WM831X_BKUP_CHG_STS)
+                        val->intval = 1;
+                else
+                        val->intval = 0;
+                break;
+
+        default:
+                ret = -EINVAL;
+                break;
+        }
+
+        return ret;
+}
+
+static enum power_supply_property wm831x_backup_props[] = {
+        POWER_SUPPLY_PROP_STATUS,
+        POWER_SUPPLY_PROP_VOLTAGE_NOW,
+        POWER_SUPPLY_PROP_PRESENT,
+};
+
+/*********************************************************************
+ *              Initialisation
+ *********************************************************************/
+
+static __devinit int wm831x_backup_probe(struct platform_device *pdev)
+{
+        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+        struct wm831x_backup *devdata;
+        struct power_supply *backup;
+        int ret, irq, i;
+
+        devdata = kzalloc(sizeof(struct wm831x_backup), GFP_KERNEL);
+        if (devdata == NULL)
+                return -ENOMEM;
+
+        devdata->wm831x = wm831x;
+        platform_set_drvdata(pdev, devdata);
+
+        backup = &devdata->backup;
+
+        /* We ignore configuration failures since we can still read
+         * back the status without enabling the charger (which may
+         * already be enabled anyway).
+         */
+        wm831x_config_backup(wm831x);
+
+        backup->name = "wm831x-backup";
+        backup->type = POWER_SUPPLY_TYPE_BATTERY;
+        backup->properties = wm831x_backup_props;
+        backup->num_properties = ARRAY_SIZE(wm831x_backup_props);
+        backup->get_property = wm831x_backup_get_prop;
+        ret = power_supply_register(&pdev->dev, backup);
+        if (ret)
+                goto err_kmalloc;
+
+        return ret;
+
+err_kmalloc:
+        kfree(devdata);
+        return ret;
+}
+
+static __devexit int wm831x_backup_remove(struct platform_device *pdev)
+{
+        struct wm831x_backup *devdata = platform_get_drvdata(pdev);
+
+        power_supply_unregister(&devdata->backup);
+        kfree(devdata);
+
+        return 0;
+}
+
+static struct platform_driver wm831x_backup_driver = {
+        .probe = wm831x_backup_probe,
+        .remove = __devexit_p(wm831x_backup_remove),
+        .driver = {
+                .name = "wm831x-backup",
+        },
+};
+
+static int __init wm831x_backup_init(void)
+{
+        return platform_driver_register(&wm831x_backup_driver);
+}
+module_init(wm831x_backup_init);
+
+static void __exit wm831x_backup_exit(void)
+{
+        platform_driver_unregister(&wm831x_backup_driver);
+}
+module_exit(wm831x_backup_exit);
+
+MODULE_DESCRIPTION("Backup battery charger driver for WM831x PMICs");
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm831x-backup");
diff --git a/drivers/power/wm831x_power.c b/drivers/power/wm831x_power.c
index 2a4c8b0b829..f85e80b1b40 100644
--- a/drivers/power/wm831x_power.c
+++ b/drivers/power/wm831x_power.c
@@ -21,7 +21,6 @@
 struct wm831x_power {
         struct wm831x *wm831x;
         struct power_supply wall;
-        struct power_supply backup;
         struct power_supply usb;
         struct power_supply battery;
 };
@@ -454,125 +453,6 @@ static irqreturn_t wm831x_bat_irq(int irq, void *data)
 
 
 /*********************************************************************
- *              Backup supply properties
- *********************************************************************/
-
-static void wm831x_config_backup(struct wm831x *wm831x)
-{
-        struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data;
-        struct wm831x_backup_pdata *pdata;
-        int ret, reg;
-
-        if (!wm831x_pdata || !wm831x_pdata->backup) {
-                dev_warn(wm831x->dev,
-                         "No backup battery charger configuration\n");
-                return;
-        }
-
-        pdata = wm831x_pdata->backup;
-
-        reg = 0;
-
-        if (pdata->charger_enable)
-                reg |= WM831X_BKUP_CHG_ENA | WM831X_BKUP_BATT_DET_ENA;
-        if (pdata->no_constant_voltage)
-                reg |= WM831X_BKUP_CHG_MODE;
-
-        switch (pdata->vlim) {
-        case 2500:
-                break;
-        case 3100:
-                reg |= WM831X_BKUP_CHG_VLIM;
-                break;
-        default:
-                dev_err(wm831x->dev, "Invalid backup voltage limit %dmV\n",
-                        pdata->vlim);
-        }
-
-        switch (pdata->ilim) {
-        case 100:
-                break;
-        case 200:
-                reg |= 1;
-                break;
-        case 300:
-                reg |= 2;
-                break;
-        case 400:
-                reg |= 3;
-                break;
-        default:
-                dev_err(wm831x->dev, "Invalid backup current limit %duA\n",
-                        pdata->ilim);
-        }
-
-        ret = wm831x_reg_unlock(wm831x);
-        if (ret != 0) {
-                dev_err(wm831x->dev, "Failed to unlock registers: %d\n", ret);
-                return;
-        }
-
-        ret = wm831x_set_bits(wm831x, WM831X_BACKUP_CHARGER_CONTROL,
-                              WM831X_BKUP_CHG_ENA_MASK |
-                              WM831X_BKUP_CHG_MODE_MASK |
-                              WM831X_BKUP_BATT_DET_ENA_MASK |
-                              WM831X_BKUP_CHG_VLIM_MASK |
-                              WM831X_BKUP_CHG_ILIM_MASK,
-                              reg);
-        if (ret != 0)
-                dev_err(wm831x->dev,
-                        "Failed to set backup charger config: %d\n", ret);
-
-        wm831x_reg_lock(wm831x);
-}
-
-static int wm831x_backup_get_prop(struct power_supply *psy,
-                                  enum power_supply_property psp,
-                                  union power_supply_propval *val)
-{
-        struct wm831x_power *wm831x_power = dev_get_drvdata(psy->dev->parent);
-        struct wm831x *wm831x = wm831x_power->wm831x;
-        int ret = 0;
-
-        ret = wm831x_reg_read(wm831x, WM831X_BACKUP_CHARGER_CONTROL);
-        if (ret < 0)
-                return ret;
-
-        switch (psp) {
-        case POWER_SUPPLY_PROP_STATUS:
-                if (ret & WM831X_BKUP_CHG_STS)
-                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
-                else
-                        val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
-                break;
-
-        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
-                ret = wm831x_power_read_voltage(wm831x, WM831X_AUX_BKUP_BATT,
-                                                val);
-                break;
-
-        case POWER_SUPPLY_PROP_PRESENT:
-                if (ret & WM831X_BKUP_CHG_STS)
-                        val->intval = 1;
-                else
-                        val->intval = 0;
-                break;
-
-        default:
-                ret = -EINVAL;
-                break;
-        }
-
-        return ret;
-}
-
-static enum power_supply_property wm831x_backup_props[] = {
-        POWER_SUPPLY_PROP_STATUS,
-        POWER_SUPPLY_PROP_VOLTAGE_NOW,
-        POWER_SUPPLY_PROP_PRESENT,
-};
-
-/*********************************************************************
  *              Initialisation
  *********************************************************************/
 
@@ -595,10 +475,7 @@ static irqreturn_t wm831x_pwr_src_irq(int irq, void *data)
 
         dev_dbg(wm831x->dev, "Power source changed\n");
 
-        /* Just notify for everything - little harm in overnotifying.
-         * The backup battery is not a power source while the system
-         * is running so skip that.
-         */
+        /* Just notify for everything - little harm in overnotifying. */
         power_supply_changed(&wm831x_power->battery);
         power_supply_changed(&wm831x_power->usb);
         power_supply_changed(&wm831x_power->wall);
@@ -613,7 +490,6 @@ static __devinit int wm831x_power_probe(struct platform_device *pdev)
         struct power_supply *usb;
         struct power_supply *battery;
         struct power_supply *wall;
-        struct power_supply *backup;
         int ret, irq, i;
 
         power = kzalloc(sizeof(struct wm831x_power), GFP_KERNEL);
@@ -626,13 +502,11 @@ static __devinit int wm831x_power_probe(struct platform_device *pdev)
         usb = &power->usb;
         battery = &power->battery;
         wall = &power->wall;
-        backup = &power->backup;
 
         /* We ignore configuration failures since we can still read back
-         * the status without enabling either of the chargers.
+         * the status without enabling the charger.
          */
         wm831x_config_battery(wm831x);
-        wm831x_config_backup(wm831x);
 
         wall->name = "wm831x-wall";
         wall->type = POWER_SUPPLY_TYPE_MAINS;
@@ -661,15 +535,6 @@ static __devinit int wm831x_power_probe(struct platform_device *pdev)
         if (ret)
                 goto err_battery;
 
-        backup->name = "wm831x-backup";
-        backup->type = POWER_SUPPLY_TYPE_BATTERY;
-        backup->properties = wm831x_backup_props;
-        backup->num_properties = ARRAY_SIZE(wm831x_backup_props);
-        backup->get_property = wm831x_backup_get_prop;
-        ret = power_supply_register(&pdev->dev, backup);
-        if (ret)
-                goto err_usb;
-
         irq = platform_get_irq_byname(pdev, "SYSLO");
         ret = wm831x_request_irq(wm831x, irq, wm831x_syslo_irq,
                                  IRQF_TRIGGER_RISING, "SYSLO",
@@ -677,7 +542,7 @@ static __devinit int wm831x_power_probe(struct platform_device *pdev)
         if (ret != 0) {
                 dev_err(&pdev->dev, "Failed to request SYSLO IRQ %d: %d\n",
                         irq, ret);
-                goto err_backup;
+                goto err_usb;
         }
 
         irq = platform_get_irq_byname(pdev, "PWR SRC");
@@ -716,8 +581,6 @@ err_bat_irq:
 err_syslo:
         irq = platform_get_irq_byname(pdev, "SYSLO");
         wm831x_free_irq(wm831x, irq, power);
-err_backup:
-        power_supply_unregister(backup);
 err_usb:
         power_supply_unregister(usb);
 err_battery:
@@ -746,7 +609,6 @@ static __devexit int wm831x_power_remove(struct platform_device *pdev)
         irq = platform_get_irq_byname(pdev, "SYSLO");
         wm831x_free_irq(wm831x, irq, wm831x_power);
 
-        power_supply_unregister(&wm831x_power->backup);
         power_supply_unregister(&wm831x_power->battery);
         power_supply_unregister(&wm831x_power->wall);
         power_supply_unregister(&wm831x_power->usb);