Re: [lm-sensors] [PATCH v2 23/26] hwmon: Add JZ4740 ADC driver

[Lars-Peter Clausen]

Jean Delvare wrote:
> On Sat, 19 Jun 2010 07:08:28 +0200, Lars-Peter Clausen wrote:
>   
>> This patch adds support for reading the ADCIN pin of ADC unit on JZ4740 SoCs.
>>
>> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
>> Cc: Jonathan Cameron <kernel@xxxxxxxxxxxxxxxxxxxxx>
>> Cc: lm-sensors@xxxxxxxxxxxxxx
>>
>> ---
>> Changes since v1
>> - Move ADC core access synchronizing from the HWMON driver to a MFD driver. The
>>   ADC driver now only reads the adcin value.
>> ---
>>  drivers/hwmon/Kconfig        |   11 +++
>>  drivers/hwmon/Makefile       |    1 +
>>  drivers/hwmon/jz4740-hwmon.c |  206 ++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 218 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/hwmon/jz4740-hwmon.c
>>
>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>> index 569082c..51fc2f6 100644
>> --- a/drivers/hwmon/Kconfig
>> +++ b/drivers/hwmon/Kconfig
>> @@ -446,6 +446,17 @@ config SENSORS_IT87
>>  	  This driver can also be built as a module.  If so, the module
>>  	  will be called it87.
>>  
>> +config SENSORS_JZ4740
>> +	tristate "Ingenic JZ4740 SoC ADC driver"
>> +	depends on MACH_JZ4740
>> +    help
>> +      If you say yes here you get support for the Ingenic JZ4740 SoC ADC core.
>> +      It is required for the JZ4740 battery and touchscreen driver and is used
>> +      to synchronize access to the adc module between those two.
>> +
>> +      This driver can also be build as a module. If so, the module will be
>> +      called jz4740-adc.
>> +
>>  config SENSORS_LM63
>>  	tristate "National Semiconductor LM63 and LM64"
>>  	depends on I2C
>> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
>> index bca0d45..dffbdff 100644
>> --- a/drivers/hwmon/Makefile
>> +++ b/drivers/hwmon/Makefile
>> @@ -55,6 +55,7 @@ obj-$(CONFIG_SENSORS_I5K_AMB)	+= i5k_amb.o
>>  obj-$(CONFIG_SENSORS_IBMAEM)	+= ibmaem.o
>>  obj-$(CONFIG_SENSORS_IBMPEX)	+= ibmpex.o
>>  obj-$(CONFIG_SENSORS_IT87)	+= it87.o
>> +obj-$(CONFIG_SENSORS_JZ4740)	+= jz4740-hwmon.o
>>  obj-$(CONFIG_SENSORS_K8TEMP)	+= k8temp.o
>>  obj-$(CONFIG_SENSORS_K10TEMP)	+= k10temp.o
>>  obj-$(CONFIG_SENSORS_LIS3LV02D) += lis3lv02d.o hp_accel.o
>> diff --git a/drivers/hwmon/jz4740-hwmon.c b/drivers/hwmon/jz4740-hwmon.c
>> new file mode 100644
>> index 0000000..f53d15e
>> --- /dev/null
>> +++ b/drivers/hwmon/jz4740-hwmon.c
>> @@ -0,0 +1,206 @@
>> +/*
>> + * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@xxxxxxxxxx>
>> + * JZ4740 SoC HWMON driver
>> + *
>> + * 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.
>> + *
>> + * 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.,
>> + * 675 Mass Ave, Cambridge, MA 02139, USA.
>> + *
>> + */
>> +
>> +#include <linux/err.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/slab.h>
>> +
>> +#include <linux/mfd/core.h>
>> +
>> +#include <linux/hwmon.h>
>> +#include <linux/hwmon-sysfs.h>
>> +
>> +struct jz4740_hwmon {
>> +	struct resource *mem;
>> +	void __iomem *base;
>> +
>> +	int irq;
>> +
>> +	struct mfd_cell *cell;
>> +	struct device *hwmon;
>> +
>> +	struct completion read_completion;
>> +
>> +	struct mutex lock;
>> +};
>> +
>> +static irqreturn_t jz4740_hwmon_irq(int irq, void *data)
>> +{
>> +	struct jz4740_hwmon *hwmon = data;
>> +
>> +	complete(&hwmon->read_completion);
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static ssize_t jz4740_hwmon_read_adcin(struct device *dev,
>> +	struct device_attribute *dev_attr, char *buf)
>> +{
>> +	struct jz4740_hwmon *hwmon = dev_get_drvdata(dev);
>> +	unsigned long t;
>> +	uint16_t val;
>> +	int ret;
>> +
>> +	mutex_lock(&hwmon->lock);
>> +
>> +	INIT_COMPLETION(hwmon->read_completion);
>> +
>> +	enable_irq(hwmon->irq);
>> +	hwmon->cell->enable(to_platform_device(dev));
>> +
>> +	t = wait_for_completion_interruptible_timeout(&hwmon->read_completion, HZ);
>> +
>> +	if (t > 0) {
>> +		val = readw(hwmon->base);
>> +		ret = sprintf(buf, "%d\n", val);
>>     
>
> What is the unit of "val"? The value returned to userspace must be in
> mV, so in most cases a simple conversion is needed in the driver.
>
>   
Right, forgot about to change it, sorry.
>> +	} else {
>> +		ret = t ? t : -ETIMEDOUT;
>> +	}
>> +
>> +	hwmon->cell->disable(to_platform_device(dev));
>> +	disable_irq(hwmon->irq);
>> +
>> +	mutex_unlock(&hwmon->lock);
>> +
>> +	return ret;
>> +}
>> +
>> +static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL, 0);
>> +
>> +static int __devinit jz4740_hwmon_probe(struct platform_device *pdev)
>> +{
>> +	int ret;
>> +	struct jz4740_hwmon *hwmon;
>> +
>> +	hwmon = kmalloc(sizeof(*hwmon), GFP_KERNEL);
>> +
>> +	hwmon->cell = pdev->dev.platform_data;
>> +
>> +	hwmon->irq = platform_get_irq(pdev, 0);
>> +	if (hwmon->irq < 0) {
>> +		ret = hwmon->irq;
>> +		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
>> +		goto err_free;
>> +	}
>> +
>> +	hwmon->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	if (!hwmon->mem) {
>> +		ret = -ENOENT;
>> +		dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
>> +		goto err_free;
>> +	}
>> +
>> +	hwmon->mem = request_mem_region(hwmon->mem->start,
>> +					resource_size(hwmon->mem), pdev->name);
>> +	if (!hwmon->mem) {
>> +		ret = -EBUSY;
>> +		dev_err(&pdev->dev, "Failed to request mmio memory region\n");
>> +		goto err_free;
>> +	}
>> +
>> +	hwmon->base = ioremap_nocache(hwmon->mem->start, resource_size(hwmon->mem));
>> +	if (!hwmon->base) {
>> +		ret = -EBUSY;
>> +		dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
>> +		goto err_release_mem_region;
>> +	}
>> +
>> +	init_completion(&hwmon->read_completion);
>> +	mutex_init(&hwmon->lock);
>> +
>> +	platform_set_drvdata(pdev, hwmon);
>> +
>> +	ret = request_irq(hwmon->irq, jz4740_hwmon_irq, 0, pdev->name, hwmon);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
>> +		goto err_iounmap;
>> +	}
>> +	disable_irq(hwmon->irq);
>> +
>> +	ret = device_create_file(&pdev->dev, &sensor_dev_attr_in0_input.dev_attr);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "Failed to create sysfs file: %d\n", ret);
>> +		goto err_free_irq;
>> +	}
>>     
>
> You must create a name attribute as well, if you want your device to be
> supported by libsensors.
>   
Ok.
>   
>> +
>> +	hwmon->hwmon = hwmon_device_register(&pdev->dev);
>> +	if (IS_ERR(hwmon->hwmon)) {
>> +		ret = PTR_ERR(hwmon->hwmon);
>> +		goto err_remove_file;
>> +	}
>> +
>> +	return 0;
>> +
>> +err_remove_file:
>> +	device_remove_file(&pdev->dev, &sensor_dev_attr_in0_input.dev_attr);
>> +err_free_irq:
>> +	free_irq(hwmon->irq, hwmon);
>> +err_iounmap:
>> +	platform_set_drvdata(pdev, NULL);
>> +	iounmap(hwmon->base);
>> +err_release_mem_region:
>> +	release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));
>> +err_free:
>> +	kfree(hwmon);
>> +
>> +	return ret;
>> +}
>> +
>> +static int __devexit jz4740_hwmon_remove(struct platform_device *pdev)
>> +{
>> +	struct jz4740_hwmon *hwmon = platform_get_drvdata(pdev);
>> +
>> +	hwmon_device_unregister(hwmon->hwmon);
>> +	device_remove_file(&pdev->dev, &sensor_dev_attr_in0_input.dev_attr);
>> +
>> +	free_irq(hwmon->irq, hwmon);
>> +
>> +	iounmap(hwmon->base);
>> +	release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));
>> +
>> +	platform_set_drvdata(pdev, NULL);
>> +	kfree(hwmon);
>> +
>> +	return 0;
>> +}
>> +
>> +struct platform_driver jz4740_hwmon_driver = {
>> +	.probe	= jz4740_hwmon_probe,
>> +	.remove = __devexit_p(jz4740_hwmon_remove),
>> +	.driver = {
>> +		.name = "jz4740-hwmon",
>> +		.owner = THIS_MODULE,
>> +	},
>> +};
>> +
>> +static int __init jz4740_hwmon_init(void)
>> +{
>> +	return platform_driver_register(&jz4740_hwmon_driver);
>> +}
>> +module_init(jz4740_hwmon_init);
>> +
>> +static void __exit jz4740_hwmon_exit(void)
>> +{
>> +	platform_driver_unregister(&jz4740_hwmon_driver);
>> +}
>> +module_exit(jz4740_hwmon_exit);
>> +
>> +MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
>> +MODULE_AUTHOR("Lars-Peter Clausen <lars@xxxxxxxxxx>");
>> +MODULE_LICENSE("GPL");
>> +MODULE_ALIAS("platform:jz4740-hwmon");
>>     
>
>   
Thanks for reviewing
-Lars

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