diff mbox

power: add poodle battery driver

Message ID 1427714679-27472-1-git-send-email-dbaryshkov@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dmitry Baryshkov March 30, 2015, 11:24 a.m. UTC
Add a driver supporting battery charging on Sharp SL-5600 (poodle).
Voltage and temperature readings are provided through add7846 hwmon
interface. Battery voltage is in1_input (mV) and temp in in0_input
(values unknown, but should be less than 2441).

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
---
 drivers/power/Kconfig          |   7 ++
 drivers/power/Makefile         |   1 +
 drivers/power/poodle_battery.c | 250 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 258 insertions(+)
 create mode 100644 drivers/power/poodle_battery.c

Comments

Sebastian Reichel April 6, 2015, 4:44 p.m. UTC | #1
Hi Dmitry,

On Mon, Mar 30, 2015 at 02:24:39PM +0300, Dmitry Eremin-Solenikov wrote:
> Add a driver supporting battery charging on Sharp SL-5600 (poodle).
> Voltage and temperature readings are provided through add7846 hwmon
> interface. Battery voltage is in1_input (mV) and temp in in0_input
> (values unknown, but should be less than 2441).

You may want to convert add7846 to iio interface, which can be
exposed via hwmon and requested by other kernel drivers (e.g. this
one).

> [...]
> +struct poodle_bat {
> +	int status;
> +	struct power_supply psy;
> +
> +	struct mutex work_lock; /* protects data */
> +
> +	bool (*is_present)(struct poodle_bat *bat);
> +	int technology;

why do you need this for a static type? You can simply set the type
directly in the get_property function?

> +};

> [...]

> +static struct gpio poodle_batt_gpios[] = {
> +	{ POODLE_GPIO_BAT_COVER,    GPIOF_IN,		"main battery cover" },
> +	{ POODLE_GPIO_CHRG_FULL,    GPIOF_IN,		"main battery full" },
> +	{ POODLE_GPIO_JK_B,	    GPIOF_OUT_INIT_LOW,	"main charge on" },
> +	{ POODLE_GPIO_CHRG_ON,	    GPIOF_OUT_INIT_LOW,	"main charge on" },
> +	{ POODLE_GPIO_BYPASS_ON,    GPIOF_OUT_INIT_LOW,	"main charge bypass" },
> +	/* on for now */
> +	{ POODLE_GPIO_ADC_TEMP_ON,  GPIOF_OUT_INIT_HIGH, "main battery temp" },
> +};

I would prefer if you use the "new" gpiod interface, see
include/linux/gpio/consumer.h

This obviously refers to the whole driver.

> [...]

> +static int poodle_battery_probe(struct platform_device *dev)
> +{
> +	int ret;
> +
> +	ret = gpio_request_array(poodle_batt_gpios,
> +				 ARRAY_SIZE(poodle_batt_gpios));
> +	if (ret)
> +		return ret;
> +
> +	mutex_init(&poodle_bat_main.work_lock);
> +
> +	INIT_WORK(&bat_work, poodle_bat_work);
> +
> +	ret = power_supply_register(&dev->dev, &poodle_bat_main.psy);
> +	if (ret)
> +		goto err_psy_reg_main;

we have devm_power_supply_register() now.

> +	ret = devm_request_irq(&dev->dev, gpio_to_irq(POODLE_GPIO_CHRG_FULL),
> +				poodle_bat_gpio_isr,
> +				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> +				"main full", NULL);
> +	if (ret)
> +		goto err_psy_irq;
> +
> +	ret = devm_request_irq(&dev->dev, gpio_to_irq(POODLE_GPIO_BAT_COVER),
> +				poodle_bat_gpio_isr,
> +				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> +				"battery cover", NULL);
> +	if (ret)
> +		goto err_psy_irq;
> +
> +	return 0;
> +
> +err_psy_irq:
> +	power_supply_unregister(&poodle_bat_main.psy);
> +
> +	cancel_work_sync(&bat_work);
> +err_psy_reg_main:
> +	gpio_free_array(poodle_batt_gpios, ARRAY_SIZE(poodle_batt_gpios));
> +
> +	return ret;
> +}

> [...]

-- Sebastian
Dmitry Baryshkov April 7, 2015, 12:34 p.m. UTC | #2
Hello,

2015-04-06 19:44 GMT+03:00, Sebastian Reichel <sre@kernel.org>:
> Hi Dmitry,
>
> On Mon, Mar 30, 2015 at 02:24:39PM +0300, Dmitry Eremin-Solenikov wrote:
>> Add a driver supporting battery charging on Sharp SL-5600 (poodle).
>> Voltage and temperature readings are provided through add7846 hwmon
>> interface. Battery voltage is in1_input (mV) and temp in in0_input
>> (values unknown, but should be less than 2441).
>
> You may want to convert add7846 to iio interface, which can be
> exposed via hwmon and requested by other kernel drivers (e.g. this
> one).

This needs a more careful thought. I have several devices in mind,
which provide touchscreen + ADC interfaces, where ADC is used
for battery voltage and temperature sensing. Sometimes additional
GPIOs are in play. Thus I'd like for now to sustain from changing
ads7846 driver. Or, at least to delay such changes, iff there will be
no real design/ideas how to handle such devices in a generic enough
way.

>
>> [...]
>> +struct poodle_bat {
>> + int status;
>> + struct power_supply psy;
>> +
>> + struct mutex work_lock; /* protects data */
>> +
>> + bool (*is_present)(struct poodle_bat *bat);
>> + int technology;
>
> why do you need this for a static type? You can simply set the type
> directly in the get_property function?

ack

>
>> +};
>
>> [...]
>
>> +static struct gpio poodle_batt_gpios[] = {
>> + { POODLE_GPIO_BAT_COVER,    GPIOF_IN, "main battery cover" },
>> + { POODLE_GPIO_CHRG_FULL,    GPIOF_IN, "main battery full" },
>> + { POODLE_GPIO_JK_B,    GPIOF_OUT_INIT_LOW, "main charge on" },
>> + { POODLE_GPIO_CHRG_ON,    GPIOF_OUT_INIT_LOW, "main charge on" },
>> + { POODLE_GPIO_BYPASS_ON,    GPIOF_OUT_INIT_LOW, "main charge bypass" },
>> + /* on for now */
>> + { POODLE_GPIO_ADC_TEMP_ON,  GPIOF_OUT_INIT_HIGH, "main battery temp" },
>> +};
>
> I would prefer if you use the "new" gpiod interface, see
> include/linux/gpio/consumer.h
>
> This obviously refers to the whole driver.
>
>> [...]
>
>> +static int poodle_battery_probe(struct platform_device *dev)
>> +{
>> + int ret;
>> +
>> + ret = gpio_request_array(poodle_batt_gpios,
>> + ARRAY_SIZE(poodle_batt_gpios));
>> + if (ret)
>> + return ret;
>> +
>> + mutex_init(&poodle_bat_main.work_lock);
>> +
>> + INIT_WORK(&bat_work, poodle_bat_work);
>> +
>> + ret = power_supply_register(&dev->dev, &poodle_bat_main.psy);
>> + if (ret)
>> + goto err_psy_reg_main;
>
> we have devm_power_supply_register() now.

Not so sure about it. I'd like to cancel work after unregistering power_supply.
I think I'll even switch from devm_request_irq back to request_irq to be able
to cancel IRQs before canceling work.

>> + ret = devm_request_irq(&dev->dev, gpio_to_irq(POODLE_GPIO_CHRG_FULL),
>> + poodle_bat_gpio_isr,
>> + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
>> + "main full", NULL);
>> + if (ret)
>> + goto err_psy_irq;
>> +
>> + ret = devm_request_irq(&dev->dev, gpio_to_irq(POODLE_GPIO_BAT_COVER),
>> + poodle_bat_gpio_isr,
>> + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
>> + "battery cover", NULL);
>> + if (ret)
>> + goto err_psy_irq;
>> +
>> + return 0;
>> +
>> +err_psy_irq:
>> + power_supply_unregister(&poodle_bat_main.psy);
>> +
>> + cancel_work_sync(&bat_work);
>> +err_psy_reg_main:
>> + gpio_free_array(poodle_batt_gpios, ARRAY_SIZE(poodle_batt_gpios));
>> +
>> + return ret;
>> +}
>
>> [...]
>
> -- Sebastian
>
Sebastian Reichel April 7, 2015, 3:40 p.m. UTC | #3
Hi,

On Tue, Apr 07, 2015 at 03:34:30PM +0300, Dmitry Eremin-Solenikov wrote:
> > On Mon, Mar 30, 2015 at 02:24:39PM +0300, Dmitry Eremin-Solenikov wrote:
> >> Add a driver supporting battery charging on Sharp SL-5600 (poodle).
> >> Voltage and temperature readings are provided through add7846 hwmon
> >> interface. Battery voltage is in1_input (mV) and temp in in0_input
> >> (values unknown, but should be less than 2441).
> >
> > You may want to convert add7846 to iio interface, which can be
> > exposed via hwmon and requested by other kernel drivers (e.g. this
> > one).
> 
> This needs a more careful thought. I have several devices in mind,
> which provide touchscreen + ADC interfaces, where ADC is used
> for battery voltage and temperature sensing. Sometimes additional
> GPIOs are in play. Thus I'd like for now to sustain from changing
> ads7846 driver. Or, at least to delay such changes, iff there will be
> no real design/ideas how to handle such devices in a generic enough
> way.

If you have more of these devices it's even more appealing to use
the IIO interface. You can basically keep the touchscreen part of
the ads7846 driver and replace hwmon with IIO. Then other kernel
drivers can request an IIO channel, but you are still able to use
hwmon interface from userspace via iio-hwmon.

> [...]

> >> +static int poodle_battery_probe(struct platform_device *dev)
> >> +{
> >> + int ret;
> >> +
> >> + ret = gpio_request_array(poodle_batt_gpios,
> >> + ARRAY_SIZE(poodle_batt_gpios));
> >> + if (ret)
> >> + return ret;
> >> +
> >> + mutex_init(&poodle_bat_main.work_lock);
> >> +
> >> + INIT_WORK(&bat_work, poodle_bat_work);
> >> +
> >> + ret = power_supply_register(&dev->dev, &poodle_bat_main.psy);
> >> + if (ret)
> >> + goto err_psy_reg_main;
> >
> > we have devm_power_supply_register() now.
> 
> Not so sure about it. I'd like to cancel work after unregistering power_supply.
> I think I'll even switch from devm_request_irq back to request_irq to be able
> to cancel IRQs before canceling work.

Why?

-- Sebastian
Dmitry Baryshkov April 11, 2015, 8:54 p.m. UTC | #4
Hello,

2015-04-07 18:40 GMT+03:00 Sebastian Reichel <sre@kernel.org>:
> Hi,
>
> On Tue, Apr 07, 2015 at 03:34:30PM +0300, Dmitry Eremin-Solenikov wrote:
>> > On Mon, Mar 30, 2015 at 02:24:39PM +0300, Dmitry Eremin-Solenikov wrote:
>> >> Add a driver supporting battery charging on Sharp SL-5600 (poodle).
>> >> Voltage and temperature readings are provided through add7846 hwmon
>> >> interface. Battery voltage is in1_input (mV) and temp in in0_input
>> >> (values unknown, but should be less than 2441).
>> >
>> > You may want to convert add7846 to iio interface, which can be
>> > exposed via hwmon and requested by other kernel drivers (e.g. this
>> > one).
>>
>> This needs a more careful thought. I have several devices in mind,
>> which provide touchscreen + ADC interfaces, where ADC is used
>> for battery voltage and temperature sensing. Sometimes additional
>> GPIOs are in play. Thus I'd like for now to sustain from changing
>> ads7846 driver. Or, at least to delay such changes, iff there will be
>> no real design/ideas how to handle such devices in a generic enough
>> way.
>
> If you have more of these devices it's even more appealing to use
> the IIO interface. You can basically keep the touchscreen part of
> the ads7846 driver and replace hwmon with IIO. Then other kernel
> drivers can request an IIO channel, but you are still able to use
> hwmon interface from userspace via iio-hwmon.

There are more chips like this, not all of them are ads7846.
I'll think about your suggestion. However I do not see this as a first
priority task.


>
>> [...]
>
>> >> +static int poodle_battery_probe(struct platform_device *dev)
>> >> +{
>> >> + int ret;
>> >> +
>> >> + ret = gpio_request_array(poodle_batt_gpios,
>> >> + ARRAY_SIZE(poodle_batt_gpios));
>> >> + if (ret)
>> >> + return ret;
>> >> +
>> >> + mutex_init(&poodle_bat_main.work_lock);
>> >> +
>> >> + INIT_WORK(&bat_work, poodle_bat_work);
>> >> +
>> >> + ret = power_supply_register(&dev->dev, &poodle_bat_main.psy);
>> >> + if (ret)
>> >> + goto err_psy_reg_main;
>> >
>> > we have devm_power_supply_register() now.
>>
>> Not so sure about it. I'd like to cancel work after unregistering power_supply.
>> I think I'll even switch from devm_request_irq back to request_irq to be able
>> to cancel IRQs before canceling work.

To be sure that there are no pending work items, after canceling the work
in driver remove callback. Basically I'd like to be sure of the following
sequence:

- shut down IRQs, so that no external events can schedule work
- unregister psy so replugging AC can not schedule work
- cancel all pending work
- free memory

Would you have any suggestions other than doing first two unregistrations
by hand?
diff mbox

Patch

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 27b751b..678f23e 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -137,6 +137,13 @@  config BATTERY_COLLIE
 	  Say Y to enable support for the battery on the Sharp Zaurus
 	  SL-5500 (collie) models.
 
+config BATTERY_POODLE
+	tristate "Sharp SL-5600 (poodle) battery"
+	depends on MACH_POODLE
+	help
+	  Say Y to enable support for the battery on the Sharp Zaurus
+	  SL-5600 (poodle) models.
+
 config BATTERY_IPAQ_MICRO
 	tristate "iPAQ Atmel Micro ASIC battery driver"
 	depends on MFD_IPAQ_MICRO
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 36f9e0d..ff3e793 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -26,6 +26,7 @@  obj-$(CONFIG_BATTERY_PMU)	+= pmu_battery.o
 obj-$(CONFIG_BATTERY_OLPC)	+= olpc_battery.o
 obj-$(CONFIG_BATTERY_TOSA)	+= tosa_battery.o
 obj-$(CONFIG_BATTERY_COLLIE)	+= collie_battery.o
+obj-$(CONFIG_BATTERY_POODLE)	+= poodle_battery.o
 obj-$(CONFIG_BATTERY_IPAQ_MICRO) += ipaq_micro_battery.o
 obj-$(CONFIG_BATTERY_WM97XX)	+= wm97xx_battery.o
 obj-$(CONFIG_BATTERY_SBS)	+= sbs-battery.o
diff --git a/drivers/power/poodle_battery.c b/drivers/power/poodle_battery.c
new file mode 100644
index 0000000..ad96e13
--- /dev/null
+++ b/drivers/power/poodle_battery.c
@@ -0,0 +1,250 @@ 
+/*
+ * Battery handler for Sharp SL-5600 Poodle device
+ *
+ * Copyright (c) 2014 Dmitry Eremin-Solenikov
+ *
+ * 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/delay.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+
+#include <mach/poodle.h>
+
+struct poodle_bat {
+	int status;
+	struct power_supply psy;
+
+	struct mutex work_lock; /* protects data */
+
+	bool (*is_present)(struct poodle_bat *bat);
+	int technology;
+};
+
+static DEFINE_MUTEX(bat_lock); /* protects gpio pins */
+static struct work_struct bat_work;
+
+static struct poodle_bat poodle_bat_main;
+
+static int poodle_bat_get_property(struct power_supply *psy,
+			    enum power_supply_property psp,
+			    union power_supply_propval *val)
+{
+	int ret = 0;
+	struct poodle_bat *bat = container_of(psy, struct poodle_bat, psy);
+
+	if (bat->is_present && !bat->is_present(bat)
+			&& psp != POWER_SUPPLY_PROP_PRESENT) {
+		return -ENODEV;
+	}
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = bat->status;
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		val->intval = bat->technology;
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = bat->is_present ? bat->is_present(bat) : 1;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	return ret;
+}
+
+static bool poodle_bat_is_present(struct poodle_bat *bat)
+{
+	return gpio_get_value(POODLE_GPIO_BAT_COVER);
+}
+
+static void poodle_bat_external_power_changed(struct power_supply *psy)
+{
+	schedule_work(&bat_work);
+}
+
+static irqreturn_t poodle_bat_gpio_isr(int irq, void *data)
+{
+	pr_info("poodle_bat_gpio irq\n");
+	schedule_work(&bat_work);
+	return IRQ_HANDLED;
+}
+
+static void poodle_bat_update(struct poodle_bat *bat)
+{
+	int old;
+	struct power_supply *psy = &bat->psy;
+
+	mutex_lock(&bat->work_lock);
+
+	old = bat->status;
+
+	if (bat->is_present && !bat->is_present(bat)) {
+		pr_info("%s not present\n", psy->name);
+		bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
+		gpio_set_value(POODLE_GPIO_JK_B, 0);
+		gpio_set_value(POODLE_GPIO_CHRG_ON, 0);
+	} else if (power_supply_am_i_supplied(psy)) {
+		gpio_set_value(POODLE_GPIO_JK_B, 1);
+		if (bat->status == POWER_SUPPLY_STATUS_DISCHARGING) {
+			gpio_set_value(POODLE_GPIO_CHRG_ON, 1);
+			msleep(20);
+		}
+
+		if (gpio_get_value(POODLE_GPIO_CHRG_FULL)) {
+			gpio_set_value(POODLE_GPIO_CHRG_ON, 0);
+			bat->status = POWER_SUPPLY_STATUS_FULL;
+		} else {
+			gpio_set_value(POODLE_GPIO_CHRG_ON, 1);
+			bat->status = POWER_SUPPLY_STATUS_CHARGING;
+		}
+	} else {
+		gpio_set_value(POODLE_GPIO_JK_B, 0);
+		gpio_set_value(POODLE_GPIO_CHRG_ON, 0);
+		bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
+	}
+
+	if (old != bat->status)
+		power_supply_changed(psy);
+
+	mutex_unlock(&bat->work_lock);
+}
+
+static void poodle_bat_work(struct work_struct *work)
+{
+	poodle_bat_update(&poodle_bat_main);
+}
+
+static enum power_supply_property poodle_bat_main_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_PRESENT,
+};
+
+static struct poodle_bat poodle_bat_main = {
+	.status = POWER_SUPPLY_STATUS_DISCHARGING,
+	.psy = {
+		.name		= "main-battery",
+		.type		= POWER_SUPPLY_TYPE_BATTERY,
+		.properties	= poodle_bat_main_props,
+		.num_properties	= ARRAY_SIZE(poodle_bat_main_props),
+		.get_property	= poodle_bat_get_property,
+		.external_power_changed = poodle_bat_external_power_changed,
+		.use_for_apm	= 1,
+	},
+
+	.is_present = poodle_bat_is_present,
+
+	.technology = POWER_SUPPLY_TECHNOLOGY_LIPO,
+};
+
+static struct gpio poodle_batt_gpios[] = {
+	{ POODLE_GPIO_BAT_COVER,    GPIOF_IN,		"main battery cover" },
+	{ POODLE_GPIO_CHRG_FULL,    GPIOF_IN,		"main battery full" },
+	{ POODLE_GPIO_JK_B,	    GPIOF_OUT_INIT_LOW,	"main charge on" },
+	{ POODLE_GPIO_CHRG_ON,	    GPIOF_OUT_INIT_LOW,	"main charge on" },
+	{ POODLE_GPIO_BYPASS_ON,    GPIOF_OUT_INIT_LOW,	"main charge bypass" },
+	/* on for now */
+	{ POODLE_GPIO_ADC_TEMP_ON,  GPIOF_OUT_INIT_HIGH, "main battery temp" },
+};
+
+#ifdef CONFIG_PM
+static int poodle_battery_suspend(struct device *dev)
+{
+	/* flush all pending status updates */
+	flush_work(&bat_work);
+	return 0;
+}
+
+static int poodle_battery_resume(struct device *dev)
+{
+	/* things may have changed while we were away */
+	schedule_work(&bat_work);
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(poodle_battery_pm,
+		poodle_battery_suspend,
+		poodle_battery_resume);
+
+#define POODLE_BATTERY_PM (&poodle_battery_pm)
+
+#else
+#define POODLE_BATTERY_PM NULL
+#endif
+
+static int poodle_battery_probe(struct platform_device *dev)
+{
+	int ret;
+
+	ret = gpio_request_array(poodle_batt_gpios,
+				 ARRAY_SIZE(poodle_batt_gpios));
+	if (ret)
+		return ret;
+
+	mutex_init(&poodle_bat_main.work_lock);
+
+	INIT_WORK(&bat_work, poodle_bat_work);
+
+	ret = power_supply_register(&dev->dev, &poodle_bat_main.psy);
+	if (ret)
+		goto err_psy_reg_main;
+
+	ret = devm_request_irq(&dev->dev, gpio_to_irq(POODLE_GPIO_CHRG_FULL),
+				poodle_bat_gpio_isr,
+				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+				"main full", NULL);
+	if (ret)
+		goto err_psy_irq;
+
+	ret = devm_request_irq(&dev->dev, gpio_to_irq(POODLE_GPIO_BAT_COVER),
+				poodle_bat_gpio_isr,
+				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+				"battery cover", NULL);
+	if (ret)
+		goto err_psy_irq;
+
+	return 0;
+
+err_psy_irq:
+	power_supply_unregister(&poodle_bat_main.psy);
+
+	cancel_work_sync(&bat_work);
+err_psy_reg_main:
+	gpio_free_array(poodle_batt_gpios, ARRAY_SIZE(poodle_batt_gpios));
+
+	return ret;
+}
+
+static int poodle_battery_remove(struct platform_device *dev)
+{
+	power_supply_unregister(&poodle_bat_main.psy);
+
+	cancel_work_sync(&bat_work);
+
+	gpio_free_array(poodle_batt_gpios, ARRAY_SIZE(poodle_batt_gpios));
+
+	return 0;
+}
+
+static struct platform_driver poodle_battery_driver = {
+	.driver.name	= "poodle-battery",
+	.probe		= poodle_battery_probe,
+	.remove		= poodle_battery_remove,
+	.driver.pm	= POODLE_BATTERY_PM,
+};
+
+module_platform_driver(poodle_battery_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Dmitry Eremin-Solenikov");
+MODULE_DESCRIPTION("Poodle battery driver");
+MODULE_ALIAS("platform:poodle-battery");