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From: Michael Hennerich <michael.hennerich@analog.com>
To: Stefan Agner <stefan@agner.ch>,
	dmitry.torokhov@gmail.com, robh+dt@kernel.org
Cc: mark.rutland@arm.com, ijc+devicetree@hellion.org.uk,
	galak@codeaurora.org, realmz6@gmail.com, broonie@kernel.org,
	jic23@kernel.org, linux-input@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/3] input: touchscreen: ad7879: add device tree support
Date: Wed, 3 Feb 2016 08:41:22 +0100	[thread overview]
Message-ID: <56B1AF22.9070404@analog.com> (raw)
In-Reply-To: <1454455218-13004-3-git-send-email-stefan@agner.ch>

On 02/03/2016 12:20 AM, Stefan Agner wrote:
> Add device tree support for the I2C and SPI variant of AD7879(-1).
> This allows to specify the touchscreen controller as a I2C client
> node or SPI slave device. Most of the options available in platform
> data are also available as device tree properties, the only exception
> being GPIO capabilities, which can not be activated through device
> tree currently.
>
> Acked-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Stefan Agner <stefan@agner.ch>

Acked-by: Michael Hennerich <michael.hennerich@analog.com>

> ---
> Changes since v2:
> - do not free driver data and irq on remove (since we are using devm now)
> Changes since v1:
> - Move device tree parsing to main driver file ad7879.c
> - Use common touchscreen_parse_properties for common properties
> - Use device_property_* API
> - Use struct ad7879 directly to store parsed values
> - Support SPI variant through device tree too (untested)
> - Add vendor prefix to vendor specific dt properties
>
>   .../bindings/input/touchscreen/ad7879.txt          |  53 ++++++++
>   drivers/input/touchscreen/ad7879-i2c.c             |  10 ++
>   drivers/input/touchscreen/ad7879-spi.c             |  10 ++
>   drivers/input/touchscreen/ad7879.c                 | 145 +++++++++++++--------
>   4 files changed, 161 insertions(+), 57 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/input/touchscreen/ad7879.txt
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/ad7879.txt b/Documentation/devicetree/bindings/input/touchscreen/ad7879.txt
> new file mode 100644
> index 0000000..e3f22d2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/ad7879.txt
> @@ -0,0 +1,53 @@
> +* Analog Devices AD7879(-1)/AD7889(-1) touchscreen interface (SPI/I2C)
> +
> +Required properties:
> +- compatible			: for SPI slave, use "adi,ad7879"
> +				  for I2C slave, use "adi,ad7879-1"
> +- reg				: SPI chipselect/I2C slave address
> +				  See spi-bus.txt for more SPI slave properties
> +- interrupt-parent		: the phandle for the interrupt controller
> +- interrupts			: touch controller interrupt
> +- touchscreen-max-pressure	: maximum reported pressure
> +- adi,resistance-plate-x	: total resistance of X-plate (for pressure
> +				  calculation)
> +Optional properties:
> +- touchscreen-swapped-x-y	: X and Y axis are swapped (boolean)
> +- adi,first-conversion-delay	: 0-12: In 128us steps (starting with 128us)
> +				  13  : 2.560ms
> +				  14  : 3.584ms
> +				  15  : 4.096ms
> +				  This property has to be a '/bits/ 8' value
> +- adi,acquisition-time		: 0: 2us
> +				  1: 4us
> +				  2: 8us
> +				  3: 16us
> +				  This property has to be a '/bits/ 8' value
> +- adi,median-filter-size	: 0: disabled
> +				  1: 4 measurements
> +				  2: 8 measurements
> +				  3: 16 measurements
> +				  This property has to be a '/bits/ 8' value
> +- adi,averaging			: 0: 2 middle values (1 if median disabled)
> +				  1: 4 middle values
> +				  2: 8 middle values
> +				  3: 16 values
> +				  This property has to be a '/bits/ 8' value
> +- adi,conversion-interval:	: 0    : convert one time only
> +				  1-255: 515us + val * 35us (up to 9.440ms)
> +				  This property has to be a '/bits/ 8' value
> +
> +Example:
> +
> +	ad7879@2c {
> +		compatible = "adi,ad7879-1";
> +		reg = <0x2c>;
> +		interrupt-parent = <&gpio1>;
> +		interrupts = <13 IRQ_TYPE_EDGE_FALLING>;
> +		touchscreen-max-pressure = <4096>;
> +		adi,resistance-plate-x = <120>;
> +		adi,first-conversion-delay = /bits/ 8 <3>;
> +		adi,acquisition-time = /bits/ 8 <1>;
> +		adi,median-filter-size = /bits/ 8 <2>;
> +		adi,averaging = /bits/ 8 <1>;
> +		adi,conversion-interval = /bits/ 8 <255>;
> +	};
> diff --git a/drivers/input/touchscreen/ad7879-i2c.c b/drivers/input/touchscreen/ad7879-i2c.c
> index d66962c..58f72e0 100644
> --- a/drivers/input/touchscreen/ad7879-i2c.c
> +++ b/drivers/input/touchscreen/ad7879-i2c.c
> @@ -10,6 +10,7 @@
>   #include <linux/i2c.h>
>   #include <linux/module.h>
>   #include <linux/types.h>
> +#include <linux/of.h>
>   #include <linux/pm.h>
>
>   #include "ad7879.h"
> @@ -91,10 +92,19 @@ static const struct i2c_device_id ad7879_id[] = {
>   };
>   MODULE_DEVICE_TABLE(i2c, ad7879_id);
>
> +#ifdef CONFIG_OF
> +static const struct of_device_id ad7879_i2c_dt_ids[] = {
> +	{ .compatible = "adi,ad7879-1", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, ad7879_i2c_dt_ids);
> +#endif
> +
>   static struct i2c_driver ad7879_i2c_driver = {
>   	.driver = {
>   		.name	= "ad7879",
>   		.pm	= &ad7879_pm_ops,
> +		.of_match_table = of_match_ptr(ad7879_i2c_dt_ids),
>   	},
>   	.probe		= ad7879_i2c_probe,
>   	.remove		= ad7879_i2c_remove,
> diff --git a/drivers/input/touchscreen/ad7879-spi.c b/drivers/input/touchscreen/ad7879-spi.c
> index 48033c2..d42b6b9 100644
> --- a/drivers/input/touchscreen/ad7879-spi.c
> +++ b/drivers/input/touchscreen/ad7879-spi.c
> @@ -10,6 +10,7 @@
>   #include <linux/pm.h>
>   #include <linux/spi/spi.h>
>   #include <linux/module.h>
> +#include <linux/of.h>
>
>   #include "ad7879.h"
>
> @@ -146,10 +147,19 @@ static int ad7879_spi_remove(struct spi_device *spi)
>   	return 0;
>   }
>
> +#ifdef CONFIG_OF
> +static const struct of_device_id ad7879_spi_dt_ids[] = {
> +	{ .compatible = "adi,ad7879", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, ad7879_spi_dt_ids);
> +#endif
> +
>   static struct spi_driver ad7879_spi_driver = {
>   	.driver = {
>   		.name	= "ad7879",
>   		.pm	= &ad7879_pm_ops,
> +		.of_match_table = of_match_ptr(ad7879_spi_dt_ids),
>   	},
>   	.probe		= ad7879_spi_probe,
>   	.remove		= ad7879_spi_remove,
> diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
> index abd0220..093cb04 100644
> --- a/drivers/input/touchscreen/ad7879.c
> +++ b/drivers/input/touchscreen/ad7879.c
> @@ -31,6 +31,7 @@
>   #include <linux/i2c.h>
>   #include <linux/gpio.h>
>
> +#include <linux/input/touchscreen.h>
>   #include <linux/platform_data/ad7879.h>
>   #include <linux/module.h>
>   #include "ad7879.h"
> @@ -126,7 +127,6 @@ struct ad7879 {
>   	u8			pen_down_acc_interval;
>   	u8			median;
>   	u16			x_plate_ohms;
> -	u16			pressure_max;
>   	u16			cmd_crtl1;
>   	u16			cmd_crtl2;
>   	u16			cmd_crtl3;
> @@ -186,7 +186,7 @@ static int ad7879_report(struct ad7879 *ts)
>   		 * Sample found inconsistent, pressure is beyond
>   		 * the maximum. Don't report it to user space.
>   		 */
> -		if (Rt > ts->pressure_max)
> +		if (Rt > input_abs_get_max(input_dev, ABS_PRESSURE))
>   			return -EINVAL;
>
>   		/*
> @@ -469,7 +469,7 @@ static void ad7879_gpio_remove(struct ad7879 *ts)
>   {
>   	const struct ad7879_platform_data *pdata = dev_get_platdata(ts->dev);
>
> -	if (pdata->gpio_export)
> +	if (pdata && pdata->gpio_export)
>   		gpiochip_remove(&ts->gc);
>
>   }
> @@ -485,6 +485,29 @@ static inline void ad7879_gpio_remove(struct ad7879 *ts)
>   }
>   #endif
>
> +static int ad7879_parse_dt(struct device *dev, struct ad7879 *ts)
> +{
> +	int err;
> +	u32 tmp;
> +
> +	err = device_property_read_u32(dev, "adi,resistance-plate-x", &tmp);
> +	if (err) {
> +		dev_err(dev, "failed to get resistance-plate-x property\n");
> +		return err;
> +	}
> +	ts->x_plate_ohms = (u16)tmp;
> +
> +	device_property_read_u8(dev, "adi,first-conversion-delay", &ts->first_conversion_delay);
> +	device_property_read_u8(dev, "adi,acquisition-time", &ts->acquisition_time);
> +	device_property_read_u8(dev, "adi,median-filter-size", &ts->median);
> +	device_property_read_u8(dev, "adi,averaging", &ts->averaging);
> +	device_property_read_u8(dev, "adi,conversion-interval", &ts->pen_down_acc_interval);
> +
> +	ts->swap_xy = device_property_read_bool(dev, "touchscreen-swapped-x-y");
> +
> +	return 0;
> +}
> +
>   struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
>   			    const struct ad7879_bus_ops *bops)
>   {
> @@ -495,22 +518,37 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
>   	u16 revid;
>
>   	if (!irq) {
> -		dev_err(dev, "no IRQ?\n");
> -		err = -EINVAL;
> -		goto err_out;
> +		dev_err(dev, "No IRQ specified\n");
> +		return ERR_PTR(-EINVAL);
>   	}
>
> -	if (!pdata) {
> -		dev_err(dev, "no platform data?\n");
> -		err = -EINVAL;
> -		goto err_out;
> +	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> +	if (!ts)
> +		return ERR_PTR(-ENOMEM);
> +
> +	if (pdata) {
> +		/* Platform data use swapped axis (backward compatibility) */
> +		ts->swap_xy = !pdata->swap_xy;
> +
> +		ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
> +
> +		ts->first_conversion_delay = pdata->first_conversion_delay;
> +		ts->acquisition_time = pdata->acquisition_time;
> +		ts->averaging = pdata->averaging;
> +		ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
> +		ts->median = pdata->median;
> +
> +	} else if (dev->of_node) {
> +		ad7879_parse_dt(dev, ts);
> +	} else {
> +		dev_err(dev, "No platform data\n");
> +		return ERR_PTR(-EINVAL);
>   	}
>
> -	ts = kzalloc(sizeof(*ts), GFP_KERNEL);
> -	input_dev = input_allocate_device();
> -	if (!ts || !input_dev) {
> -		err = -ENOMEM;
> -		goto err_free_mem;
> +	input_dev = devm_input_allocate_device(dev);
> +	if (!input_dev) {
> +		dev_err(dev, "Failed to allocate input device\n");
> +		return ERR_PTR(-ENOMEM);
>   	}
>
>   	ts->bops = bops;
> @@ -518,20 +556,7 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
>   	ts->input = input_dev;
>   	ts->irq = irq;
>
> -	/* Use swapped axis by default (backward compatibility) */
> -	ts->swap_xy = !pdata->swap_xy;
> -
>   	setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
> -
> -	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
> -	ts->pressure_max = pdata->pressure_max ? : ~0;
> -
> -	ts->first_conversion_delay = pdata->first_conversion_delay;
> -	ts->acquisition_time = pdata->acquisition_time;
> -	ts->averaging = pdata->averaging;
> -	ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
> -	ts->median = pdata->median;
> -
>   	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
>
>   	input_dev->name = "AD7879 Touchscreen";
> @@ -552,21 +577,33 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
>   	__set_bit(EV_KEY, input_dev->evbit);
>   	__set_bit(BTN_TOUCH, input_dev->keybit);
>
> -	input_set_abs_params(input_dev, ABS_X,
> -			pdata->x_min ? : 0,
> -			pdata->x_max ? : MAX_12BIT,
> -			0, 0);
> -	input_set_abs_params(input_dev, ABS_Y,
> -			pdata->y_min ? : 0,
> -			pdata->y_max ? : MAX_12BIT,
> -			0, 0);
> -	input_set_abs_params(input_dev, ABS_PRESSURE,
> -			pdata->pressure_min, pdata->pressure_max, 0, 0);
> +	if (pdata) {
> +		input_set_abs_params(input_dev, ABS_X,
> +				pdata->x_min ? : 0,
> +				pdata->x_max ? : MAX_12BIT,
> +				0, 0);
> +		input_set_abs_params(input_dev, ABS_Y,
> +				pdata->y_min ? : 0,
> +				pdata->y_max ? : MAX_12BIT,
> +				0, 0);
> +		input_set_abs_params(input_dev, ABS_PRESSURE,
> +				pdata->pressure_min,
> +				pdata->pressure_max ? : ~0,
> +				0, 0);
> +	} else {
> +		input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
> +		input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
> +		touchscreen_parse_properties(input_dev, false);
> +		if (!input_abs_get_max(input_dev, ABS_PRESSURE)) {
> +			dev_err(dev, "Touchscreen pressure is not specified\n");
> +			return ERR_PTR(-EINVAL);
> +		}
> +	}
>
>   	err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
>   	if (err < 0) {
>   		dev_err(dev, "Failed to write %s\n", input_dev->name);
> -		goto err_free_mem;
> +		return ERR_PTR(err);
>   	}
>
>   	revid = ad7879_read(ts, AD7879_REG_REVID);
> @@ -575,8 +612,7 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
>   	if (input_dev->id.product != devid) {
>   		dev_err(dev, "Failed to probe %s (%x vs %x)\n",
>   			input_dev->name, devid, revid);
> -		err = -ENODEV;
> -		goto err_free_mem;
> +		return ERR_PTR(-ENODEV);
>   	}
>
>   	ts->cmd_crtl3 = AD7879_YPLUS_BIT |
> @@ -596,23 +632,25 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
>   			AD7879_ACQ(ts->acquisition_time) |
>   			AD7879_TMR(ts->pen_down_acc_interval);
>
> -	err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
> -				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> -				   dev_name(dev), ts);
> +	err = devm_request_threaded_irq(dev, ts->irq, NULL, ad7879_irq,
> +					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> +					dev_name(dev), ts);
>   	if (err) {
> -		dev_err(dev, "irq %d busy?\n", ts->irq);
> -		goto err_free_mem;
> +		dev_err(dev, "Failed to request IRQ: %d\n", err);
> +		return ERR_PTR(err);
>   	}
>
>   	__ad7879_disable(ts);
>
>   	err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
>   	if (err)
> -		goto err_free_irq;
> +		goto err_out;
>
> -	err = ad7879_gpio_add(ts, pdata);
> -	if (err)
> -		goto err_remove_attr;
> +	if (pdata) {
> +		err = ad7879_gpio_add(ts, pdata);
> +		if (err)
> +			goto err_remove_attr;
> +	}
>
>   	err = input_register_device(input_dev);
>   	if (err)
> @@ -624,11 +662,6 @@ err_remove_gpio:
>   	ad7879_gpio_remove(ts);
>   err_remove_attr:
>   	sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
> -err_free_irq:
> -	free_irq(ts->irq, ts);
> -err_free_mem:
> -	input_free_device(input_dev);
> -	kfree(ts);
>   err_out:
>   	return ERR_PTR(err);
>   }
> @@ -638,9 +671,7 @@ void ad7879_remove(struct ad7879 *ts)
>   {
>   	ad7879_gpio_remove(ts);
>   	sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
> -	free_irq(ts->irq, ts);
>   	input_unregister_device(ts->input);
> -	kfree(ts);
>   }
>   EXPORT_SYMBOL(ad7879_remove);
>
>


-- 
Greetings,
Michael

  reply	other threads:[~2016-02-03  7:41 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-02 23:20 [PATCH v3 1/3] input: touchscreen: ad7879: move header to platform_data directory Stefan Agner
2016-02-02 23:20 ` [PATCH v3 2/3] input: touchscreen: ad7879: fix default x/y axis assignment Stefan Agner
2016-02-03  7:41   ` Michael Hennerich
2016-02-02 23:20 ` [PATCH v3 3/3] input: touchscreen: ad7879: add device tree support Stefan Agner
2016-02-03  7:41   ` Michael Hennerich [this message]
2016-03-08 18:50   ` Dmitry Torokhov
2016-03-08 17:48 ` [PATCH v3 1/3] input: touchscreen: ad7879: move header to platform_data directory Stefan Agner
2016-03-08 18:48   ` Dmitry Torokhov

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