POWER: Add JZ4740 battery driver.

Add support for the battery voltage measurement part of the JZ4740 ADC unit.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1416/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 457 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 8e9ba177d817..1e5506be39b4 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -142,4 +142,15 @@ config CHARGER_PCF50633
         help
          Say Y to include support for NXP PCF50633 Main Battery Charger.
 
+config BATTERY_JZ4740
+        tristate "Ingenic JZ4740 battery"
+        depends on MACH_JZ4740
+        depends on MFD_JZ4740_ADC
+        help
+          Say Y to enable support for the battery on Ingenic JZ4740 based
+          boards.
+
+          This driver can be build as a module. If so, the module will be
+          called jz4740-battery.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 00050809a6c7..cf95009d9bcd 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -34,3 +34,4 @@ obj-$(CONFIG_BATTERY_DA9030)	+= da9030_battery.o
 obj-$(CONFIG_BATTERY_MAX17040)  += max17040_battery.o
 obj-$(CONFIG_BATTERY_Z2)        += z2_battery.o
 obj-$(CONFIG_CHARGER_PCF50633)  += pcf50633-charger.o
+obj-$(CONFIG_BATTERY_JZ4740)    += jz4740-battery.o
diff --git a/drivers/power/jz4740-battery.c b/drivers/power/jz4740-battery.c
new file mode 100644
index 000000000000..20c4b952e9bd
--- /dev/null
+++ b/drivers/power/jz4740-battery.c
@@ -0,0 +1,445 @@
+/*
+ * Battery measurement code for Ingenic JZ SOC.
+ *
+ * Copyright (C) 2009 Jiejing Zhang <kzjeef@gmail.com>
+ * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * based on tosa_battery.c
+ *
+ * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
+*
+ * 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/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/mfd/core.h>
+#include <linux/power_supply.h>
+
+#include <linux/power/jz4740-battery.h>
+#include <linux/jz4740-adc.h>
+
+struct jz_battery {
+        struct jz_battery_platform_data *pdata;
+        struct platform_device *pdev;
+
+        struct resource *mem;
+        void __iomem *base;
+
+        int irq;
+        int charge_irq;
+
+        struct mfd_cell *cell;
+
+        int status;
+        long voltage;
+
+        struct completion read_completion;
+
+        struct power_supply battery;
+        struct delayed_work work;
+};
+
+static inline struct jz_battery *psy_to_jz_battery(struct power_supply *psy)
+{
+        return container_of(psy, struct jz_battery, battery);
+}
+
+static irqreturn_t jz_battery_irq_handler(int irq, void *devid)
+{
+        struct jz_battery *battery = devid;
+
+        complete(&battery->read_completion);
+        return IRQ_HANDLED;
+}
+
+static long jz_battery_read_voltage(struct jz_battery *battery)
+{
+        unsigned long t;
+        unsigned long val;
+        long voltage;
+
+        INIT_COMPLETION(battery->read_completion);
+
+        enable_irq(battery->irq);
+        battery->cell->enable(battery->pdev);
+
+        t = wait_for_completion_interruptible_timeout(&battery->read_completion,
+                HZ);
+
+        if (t > 0) {
+                val = readw(battery->base) & 0xfff;
+
+                if (battery->pdata->info.voltage_max_design <= 2500000)
+                        val = (val * 78125UL) >> 7UL;
+                else
+                        val = ((val * 924375UL) >> 9UL) + 33000;
+                voltage = (long)val;
+        } else {
+                voltage = t ? t : -ETIMEDOUT;
+        }
+
+        battery->cell->disable(battery->pdev);
+        disable_irq(battery->irq);
+
+        return voltage;
+}
+
+static int jz_battery_get_capacity(struct power_supply *psy)
+{
+        struct jz_battery *jz_battery = psy_to_jz_battery(psy);
+        struct power_supply_info *info = &jz_battery->pdata->info;
+        long voltage;
+        int ret;
+        int voltage_span;
+
+        voltage = jz_battery_read_voltage(jz_battery);
+
+        if (voltage < 0)
+                return voltage;
+
+        voltage_span = info->voltage_max_design - info->voltage_min_design;
+        ret = ((voltage - info->voltage_min_design) * 100) / voltage_span;
+
+        if (ret > 100)
+                ret = 100;
+        else if (ret < 0)
+                ret = 0;
+
+        return ret;
+}
+
+static int jz_battery_get_property(struct power_supply *psy,
+        enum power_supply_property psp, union power_supply_propval *val)
+{
+        struct jz_battery *jz_battery = psy_to_jz_battery(psy);
+        struct power_supply_info *info = &jz_battery->pdata->info;
+        long voltage;
+
+        switch (psp) {
+        case POWER_SUPPLY_PROP_STATUS:
+                val->intval = jz_battery->status;
+                break;
+        case POWER_SUPPLY_PROP_TECHNOLOGY:
+                val->intval = jz_battery->pdata->info.technology;
+                break;
+        case POWER_SUPPLY_PROP_HEALTH:
+                voltage = jz_battery_read_voltage(jz_battery);
+                if (voltage < info->voltage_min_design)
+                        val->intval = POWER_SUPPLY_HEALTH_DEAD;
+                else
+                        val->intval = POWER_SUPPLY_HEALTH_GOOD;
+                break;
+        case POWER_SUPPLY_PROP_CAPACITY:
+                val->intval = jz_battery_get_capacity(psy);
+                break;
+        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+                val->intval = jz_battery_read_voltage(jz_battery);
+                if (val->intval < 0)
+                        return val->intval;
+                break;
+        case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+                val->intval = info->voltage_max_design;
+                break;
+        case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+                val->intval = info->voltage_min_design;
+                break;
+        case POWER_SUPPLY_PROP_PRESENT:
+                val->intval = 1;
+                break;
+        default:
+                return -EINVAL;
+        }
+        return 0;
+}
+
+static void jz_battery_external_power_changed(struct power_supply *psy)
+{
+        struct jz_battery *jz_battery = psy_to_jz_battery(psy);
+
+        cancel_delayed_work(&jz_battery->work);
+        schedule_delayed_work(&jz_battery->work, 0);
+}
+
+static irqreturn_t jz_battery_charge_irq(int irq, void *data)
+{
+        struct jz_battery *jz_battery = data;
+
+        cancel_delayed_work(&jz_battery->work);
+        schedule_delayed_work(&jz_battery->work, 0);
+
+        return IRQ_HANDLED;
+}
+
+static void jz_battery_update(struct jz_battery *jz_battery)
+{
+        int status;
+        long voltage;
+        bool has_changed = false;
+        int is_charging;
+
+        if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
+                is_charging = gpio_get_value(jz_battery->pdata->gpio_charge);
+                is_charging ^= jz_battery->pdata->gpio_charge_active_low;
+                if (is_charging)
+                        status = POWER_SUPPLY_STATUS_CHARGING;
+                else
+                        status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+
+                if (status != jz_battery->status) {
+                        jz_battery->status = status;
+                        has_changed = true;
+                }
+        }
+
+        voltage = jz_battery_read_voltage(jz_battery);
+        if (abs(voltage - jz_battery->voltage) < 50000) {
+                jz_battery->voltage = voltage;
+                has_changed = true;
+        }
+
+        if (has_changed)
+                power_supply_changed(&jz_battery->battery);
+}
+
+static enum power_supply_property jz_battery_properties[] = {
+        POWER_SUPPLY_PROP_STATUS,
+        POWER_SUPPLY_PROP_TECHNOLOGY,
+        POWER_SUPPLY_PROP_HEALTH,
+        POWER_SUPPLY_PROP_CAPACITY,
+        POWER_SUPPLY_PROP_VOLTAGE_NOW,
+        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+        POWER_SUPPLY_PROP_PRESENT,
+};
+
+static void jz_battery_work(struct work_struct *work)
+{
+        /* Too small interval will increase system workload */
+        const int interval = HZ * 30;
+        struct jz_battery *jz_battery = container_of(work, struct jz_battery,
+                                            work.work);
+
+        jz_battery_update(jz_battery);
+        schedule_delayed_work(&jz_battery->work, interval);
+}
+
+static int __devinit jz_battery_probe(struct platform_device *pdev)
+{
+        int ret = 0;
+        struct jz_battery_platform_data *pdata = pdev->dev.parent->platform_data;
+        struct jz_battery *jz_battery;
+        struct power_supply *battery;
+
+        jz_battery = kzalloc(sizeof(*jz_battery), GFP_KERNEL);
+        if (!jz_battery) {
+                dev_err(&pdev->dev, "Failed to allocate driver structure\n");
+                return -ENOMEM;
+        }
+
+        jz_battery->cell = pdev->dev.platform_data;
+
+        jz_battery->irq = platform_get_irq(pdev, 0);
+        if (jz_battery->irq < 0) {
+                ret = jz_battery->irq;
+                dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
+                goto err_free;
+        }
+
+        jz_battery->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!jz_battery->mem) {
+                ret = -ENOENT;
+                dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
+                goto err_free;
+        }
+
+        jz_battery->mem = request_mem_region(jz_battery->mem->start,
+                                resource_size(jz_battery->mem), pdev->name);
+        if (!jz_battery->mem) {
+                ret = -EBUSY;
+                dev_err(&pdev->dev, "Failed to request mmio memory region\n");
+                goto err_free;
+        }
+
+        jz_battery->base = ioremap_nocache(jz_battery->mem->start,
+                                resource_size(jz_battery->mem));
+        if (!jz_battery->base) {
+                ret = -EBUSY;
+                dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
+                goto err_release_mem_region;
+        }
+
+        battery = &jz_battery->battery;
+        battery->name = pdata->info.name;
+        battery->type = POWER_SUPPLY_TYPE_BATTERY;
+        battery->properties     = jz_battery_properties;
+        battery->num_properties = ARRAY_SIZE(jz_battery_properties);
+        battery->get_property = jz_battery_get_property;
+        battery->external_power_changed = jz_battery_external_power_changed;
+        battery->use_for_apm = 1;
+
+        jz_battery->pdata = pdata;
+        jz_battery->pdev = pdev;
+
+        init_completion(&jz_battery->read_completion);
+
+        INIT_DELAYED_WORK(&jz_battery->work, jz_battery_work);
+
+        ret = request_irq(jz_battery->irq, jz_battery_irq_handler, 0, pdev->name,
+                        jz_battery);
+        if (ret) {
+                dev_err(&pdev->dev, "Failed to request irq %d\n", ret);
+                goto err_iounmap;
+        }
+        disable_irq(jz_battery->irq);
+
+        if (gpio_is_valid(pdata->gpio_charge)) {
+                ret = gpio_request(pdata->gpio_charge, dev_name(&pdev->dev));
+                if (ret) {
+                        dev_err(&pdev->dev, "charger state gpio request failed.\n");
+                        goto err_free_irq;
+                }
+                ret = gpio_direction_input(pdata->gpio_charge);
+                if (ret) {
+                        dev_err(&pdev->dev, "charger state gpio set direction failed.\n");
+                        goto err_free_gpio;
+                }
+
+                jz_battery->charge_irq = gpio_to_irq(pdata->gpio_charge);
+
+                if (jz_battery->charge_irq >= 0) {
+                        ret = request_irq(jz_battery->charge_irq,
+                                    jz_battery_charge_irq,
+                                    IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+                                    dev_name(&pdev->dev), jz_battery);
+                        if (ret) {
+                                dev_err(&pdev->dev, "Failed to request charge irq: %d\n", ret);
+                                goto err_free_gpio;
+                        }
+                }
+        } else {
+                jz_battery->charge_irq = -1;
+        }
+
+        if (jz_battery->pdata->info.voltage_max_design <= 2500000)
+                jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB,
+                        JZ_ADC_CONFIG_BAT_MB);
+        else
+                jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB, 0);
+
+        ret = power_supply_register(&pdev->dev, &jz_battery->battery);
+        if (ret) {
+                dev_err(&pdev->dev, "power supply battery register failed.\n");
+                goto err_free_charge_irq;
+        }
+
+        platform_set_drvdata(pdev, jz_battery);
+        schedule_delayed_work(&jz_battery->work, 0);
+
+        return 0;
+
+err_free_charge_irq:
+        if (jz_battery->charge_irq >= 0)
+                free_irq(jz_battery->charge_irq, jz_battery);
+err_free_gpio:
+        if (gpio_is_valid(pdata->gpio_charge))
+                gpio_free(jz_battery->pdata->gpio_charge);
+err_free_irq:
+        free_irq(jz_battery->irq, jz_battery);
+err_iounmap:
+        platform_set_drvdata(pdev, NULL);
+        iounmap(jz_battery->base);
+err_release_mem_region:
+        release_mem_region(jz_battery->mem->start, resource_size(jz_battery->mem));
+err_free:
+        kfree(jz_battery);
+        return ret;
+}
+
+static int __devexit jz_battery_remove(struct platform_device *pdev)
+{
+        struct jz_battery *jz_battery = platform_get_drvdata(pdev);
+
+        cancel_delayed_work_sync(&jz_battery->work);
+
+        if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
+                if (jz_battery->charge_irq >= 0)
+                        free_irq(jz_battery->charge_irq, jz_battery);
+                gpio_free(jz_battery->pdata->gpio_charge);
+        }
+
+        power_supply_unregister(&jz_battery->battery);
+
+        free_irq(jz_battery->irq, jz_battery);
+
+        iounmap(jz_battery->base);
+        release_mem_region(jz_battery->mem->start, resource_size(jz_battery->mem));
+
+        return 0;
+}
+
+#ifdef CONFIG_PM
+static int jz_battery_suspend(struct device *dev)
+{
+        struct jz_battery *jz_battery = dev_get_drvdata(dev);
+
+        cancel_delayed_work_sync(&jz_battery->work);
+        jz_battery->status = POWER_SUPPLY_STATUS_UNKNOWN;
+
+        return 0;
+}
+
+static int jz_battery_resume(struct device *dev)
+{
+        struct jz_battery *jz_battery = dev_get_drvdata(dev);
+
+        schedule_delayed_work(&jz_battery->work, 0);
+
+        return 0;
+}
+
+static const struct dev_pm_ops jz_battery_pm_ops = {
+        .suspend        = jz_battery_suspend,
+        .resume         = jz_battery_resume,
+};
+
+#define JZ_BATTERY_PM_OPS (&jz_battery_pm_ops)
+#else
+#define JZ_BATTERY_PM_OPS NULL
+#endif
+
+static struct platform_driver jz_battery_driver = {
+        .probe          = jz_battery_probe,
+        .remove         = __devexit_p(jz_battery_remove),
+        .driver = {
+                .name = "jz4740-battery",
+                .owner = THIS_MODULE,
+                .pm = JZ_BATTERY_PM_OPS,
+        },
+};
+
+static int __init jz_battery_init(void)
+{
+        return platform_driver_register(&jz_battery_driver);
+}
+module_init(jz_battery_init);
+
+static void __exit jz_battery_exit(void)
+{
+        platform_driver_unregister(&jz_battery_driver);
+}
+module_exit(jz_battery_exit);
+
+MODULE_ALIAS("platform:jz4740-battery");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("JZ4740 SoC battery driver");