Subject: [lm-sensors] [PATCH v2 2/5] input: sun4i-ts: Add support for temperature sensor

From: [email-masked] (Hans de Goede)
Date: Tue, 31 Dec 2013 11:57:18 +0100

Hi,

On 12/27/2013 05:34 PM, Guenter Roeck wrote:
> On Fri, Dec 27, 2013 at 03:59:56PM +0100, Hans de Goede wrote:
>> The sun4i resisitive touchscreen controller also comes with a built-in
>> temperature sensor. This commit adds support for it.
>>
>> This commit also introduces a new "ts-attached" device-tree property,
>> when this is not set, the input part of the driver won't register. This way
>> the internal temperature sensor can be used to measure the SoC temperature
>> independent of there actually being a touchscreen attached to the controller.
>>
>> Signed-off-by: Hans de Goede <[email-masked]>
>
> Hi Hans,
>
> Almost good, except for a couple of nitpicks and one moe question.
> Assuming you fix the nitpicks and the question is not a concern,
> feel free to add
>
> Reviewed-by: Guenter Roeck <[email-masked]>
>
> Guenter
>
>> ---
>>   .../bindings/input/touchscreen/sun4i.txt           |   6 +
>>   drivers/input/touchscreen/sun4i-ts.c               | 129 ++++++++++++++++-----
>>   2 files changed, 109 insertions(+), 26 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
>> index e45927e..1fffd11 100644
>> --- a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
>> +++ b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
>> @@ -6,10 +6,16 @@ Required properties:
>>    - reg: mmio address range of the chip
>>    - interrupts: interrupt to which the chip is connected
>>
>> +Optional properties:
>> + - ts-attached: boolean set this to tell the driver that an actual touchscreen
>> +		is attached and that it should register an input device,
>> +		without this it only registers the builtin temperate sensor
>> +
>>   Example:
>>
>>   	rtp: rtp at 01c25000 {
>>   		compatible = "allwinner,sun4i-ts";
>>   		reg = <0x01c25000 0x100>;
>>   		interrupts = <29>;
>> +		ts-attached;
>>   	};
>> diff --git a/drivers/input/touchscreen/sun4i-ts.c b/drivers/input/touchscreen/sun4i-ts.c
>> index 10839d2..2d437f6 100644
>> --- a/drivers/input/touchscreen/sun4i-ts.c
>> +++ b/drivers/input/touchscreen/sun4i-ts.c
>> @@ -3,6 +3,9 @@
>>    *
>>    * Copyright (C) 2013 - 2014 Hans de Goede <[email-masked]>
>>    *
>> + * The hwmon parts are based on work by Corentin LABBE which is:
>> + * Copyright (C) 2013 Corentin LABBE <[email-masked]>
>> + *
>>    * 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
>> @@ -30,6 +33,7 @@
>>    */
>>
>>   #include <linux/err.h>
>> +#include <linux/hwmon.h>
>>   #include <linux/init.h>
>>   #include <linux/input.h>
>>   #include <linux/interrupt.h>
>> @@ -106,6 +110,7 @@ struct sun4i_ts_data {
>>   	void __iomem *base;
>>   	unsigned int irq;
>>   	bool ignore_fifo_data;
>> +	int temp_data;
>>   };
>>
>>   static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
>> @@ -115,6 +120,12 @@ static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
>>
>>   	reg_val  = readl(ts->base + TP_INT_FIFOS);
>>
>> +	if (reg_val & TEMP_DATA_PENDING)
>> +		ts->temp_data = readl(ts->base + TEMP_DATA);
>
> Is this read guaranteed to return 0 in the upper bit, or in other words is it
> guaranteed to never return 0xffffffff ? Otherwise there might be a problem with
> the implicit conversion to a negative integer.

Yes what is being read is a 12 bit unsigned value, with all the upper bits set to 0.

>
>> +
>> +	if (!ts->input)
>> +		goto leave;
>> +
>>   	if (reg_val & FIFO_DATA_PENDING) {
>>   		x = readl(ts->base + TP_DATA);
>>   		y = readl(ts->base + TP_DATA);
>> @@ -140,6 +151,7 @@ static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
>>   		input_sync(ts->input);
>>   	}
>>
>> +leave:
>>   	writel(reg_val, ts->base + TP_INT_FIFOS);
>>
>>   	return IRQ_HANDLED;
>> @@ -149,9 +161,9 @@ static int sun4i_ts_open(struct input_dev *dev)
>>   {
>>   	struct sun4i_ts_data *ts = input_get_drvdata(dev);
>>
>> -	/* Flush, set trig level to 1, enable data and up irqs */
>> -	writel(DATA_IRQ_EN(1) | FIFO_TRIG(1) |FIFO_FLUSH(1) | TP_UP_IRQ_EN(1),
>> -	       ts->base + TP_INT_FIFOC);
>> +	/* Flush, set trig level to 1, enable temp, data and up irqs */
>> +	writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) |
>> +		TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
>>
>>   	return 0;
>>   }
>> @@ -160,40 +172,76 @@ static void sun4i_ts_close(struct input_dev *dev)
>>   {
>>   	struct sun4i_ts_data *ts = input_get_drvdata(dev);
>>
>> -	/* Deactivate all IRQs */
>> -	writel(0, ts->base + TP_INT_FIFOC);
>> +	/* Deactivate all input IRQs */
>> +	writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
>>   	synchronize_irq(ts->irq);
>>   }
>>
>> +static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
>> +			 char *buf)
>> +{
>> +	struct sun4i_ts_data *ts = dev_get_drvdata(dev);
>> +
>> +	/* No temp_data until the first irq */
>> +	if (ts->temp_data == -1)
>> +		return -EAGAIN;
>> +
>> +	return sprintf(buf, "%d\n", (ts->temp_data - 1447) * 100);
>> +}
>> +
>> +static ssize_t show_temp_label(struct device *dev,
>> +			      struct device_attribute *devattr, char *buf)
>> +{
>> +	return sprintf(buf, "SoC temperature\n");
>> +}
>> +
>> +static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
>> +static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL);
>> +
>> +static struct attribute *sun4i_ts_attrs[] = {
>> +	&dev_attr_temp1_input.attr,
>> +	&dev_attr_temp1_label.attr,
>> +	NULL
>> +};
>> +ATTRIBUTE_GROUPS(sun4i_ts);
>> +
>>   static int sun4i_ts_probe(struct platform_device *pdev)
>>   {
>>   	struct sun4i_ts_data *ts;
>>   	struct device *dev = &pdev->dev;
>> +	struct device_node *np =dev->of_node;
>
> Missing space after '=' (checkpatch error).
>
>> +	struct device *hwmon;
>>   	int ret;
>> +	bool ts_attached;
>> +
>> +	ts_attached = of_property_read_bool(np, "ts-attached");
>>
>>   	ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL);
>>   	if (!ts)
>>   		return -ENOMEM;
>>
>>   	ts->dev = dev;
>> -
>> -	ts->input = devm_input_allocate_device(dev);
>> -	if (!ts->input)
>> -		return -ENOMEM;
>> -
>> -	ts->input->name = pdev->name;
>> -	ts->input->phys = "sun4i_ts/input0";
>> -	ts->input->open = sun4i_ts_open;
>> -	ts->input->close = sun4i_ts_close;
>> -	ts->input->id.bustype = BUS_HOST;
>> -	ts->input->id.vendor = 0x0001;
>> -	ts->input->id.product = 0x0001;
>> -	ts->input->id.version = 0x0100;
>> -	ts->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
>> -	set_bit(BTN_TOUCH, ts->input->keybit);
>> -	input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0);
>> -	input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0);
>> -	input_set_drvdata(ts->input, ts);
>> +	ts->temp_data = -1;
>> +
>> +	if (ts_attached) {
>> +		ts->input = devm_input_allocate_device(dev);
>> +		if (!ts->input)
>> +			return -ENOMEM;
>> +
>> +		ts->input->name = pdev->name;
>> +		ts->input->phys = "sun4i_ts/input0";
>> +		ts->input->open = sun4i_ts_open;
>> +		ts->input->close = sun4i_ts_close;
>> +		ts->input->id.bustype = BUS_HOST;
>> +		ts->input->id.vendor = 0x0001;
>> +		ts->input->id.product = 0x0001;
>> +		ts->input->id.version = 0x0100;
>> +		ts->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
>> +		set_bit(BTN_TOUCH, ts->input->keybit);
>> +		input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0);
>> +		input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0);
>> +		input_set_drvdata(ts->input, ts);
>> +	}
>>
>>   	ts->base = devm_ioremap_resource(dev,
>>   			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
>> @@ -232,14 +280,42 @@ static int sun4i_ts_probe(struct platform_device *pdev)
>>   	writel(STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1) | TP_MODE_EN(1),
>>   	       ts->base + TP_CTRL1);
>>
>> -	ret = input_register_device(ts->input);
>> -	if (ret)
>> -		return ret;
>> +	hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts",
>> +						       ts, sun4i_ts_groups);
>> +	if (IS_ERR(hwmon)) {
>> +		return PTR_ERR(hwmon);
>> +	}
>
> { } are not needed here (checkpatch warning).

Oops, should have run checkpatch on v2 too, my bad. Both fixed now.

Regards,

Hans