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SubjectRE: [PATCH 1/1] Input/Touchscreen Driver: add support AD7877touchscreen driver (try #5)
Date
From
>From: Dmitry Torokhov [mailto:dmitry.torokhov@gmail.com]
>Subject: Re: [PATCH 1/1] Input/Touchscreen Driver: add support
>AD7877touchscreen driver (try #5)
>
>Hi Bryan, Michael,
>
>On Fri, Oct 17, 2008 at 01:56:08AM +0800, Bryan Wu wrote:
>> From: Michael Hennerich <michael.hennerich@analog.com>
>>
>> [try #5]
>> - Fix indention
>> - Lock spi_async()
>> - Remove useless header comments
>> - Use strict_strtoul
>> - Use EDGE triggered interrupts ?\226?\128?\147 this simplifies some
of
>the IRQ handling.
>> - Fix error cleanup path
>> - Remove duplicated code
>> - SPI access functions parameter use struct spi_device
>>
>
>I looked at the latest version of the driver in Andrew's queue and I
>think it needs the following changes:
>
>- you can't have parts of bitfield updated from IRQ context and part
from
> process context unless every field is protected by the same spinlock.
>
>- You need more full mutual exclusion between enable and disable so you
> don't inadvertingly kill the timer if you disable and enable from
> different processes.
>
>- I think you need serialization in various store() methods so that
> consistent values are written into chip's registers.
>
>- There were coule of inverted logic errors in disabling chip code.
>
>- Kay is trying to get rid of bus_id in devices, you need to use
> dev_name() instead.

Andrew folded a patch addressing this issue, submitted by
[randy.dunlap@oracle.com: touchscreen/ad787x: don't use bus_id] into his

[patch 03/22] input: AD7879 Touchscreen driver patch.

You must have missed this one.

>
>Could you please try the patch below and let me know if the driver
still
>works so I can commit it. I also did some formatting changes, I hope
you
>don't mind. Thanks!

Thanks a lot for your great efforts!

But your patch doesn't apply on Andrews folded patch send to you last
Wednesday. I also tried it without the "don't use bus_id" patch.

Can you please send me your modified files?

Best regards,
Michael


>
>--
>Dmitry
>
>Input: ad7877 fixups
>
>Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
>---
>
> drivers/input/touchscreen/ad7877.c | 226
++++++++++++++++----------------
>----
> 1 files changed, 99 insertions(+), 127 deletions(-)
>
>
>diff --git a/drivers/input/touchscreen/ad7877.c
>b/drivers/input/touchscreen/ad7877.c
>index 6615bcd..6702364 100644
>--- a/drivers/input/touchscreen/ad7877.c
>+++ b/drivers/input/touchscreen/ad7877.c
>@@ -1,7 +1,7 @@
> /*
> * File: drivers/input/touchscreen/ad7877.c
> *
>- * Based on: ads7846.c
>+ * Based on: ads7846.c
> *
> * Copyright (C) 2006-2008 Michael Hennerich, Analog
Devices Inc.
> *
>@@ -185,21 +185,24 @@ struct ad7877 {
> u8 averaging;
> u8 pen_down_acc_interval;
>
>- u16 conversion_data[AD7877_NR_SENSE];
>+ u16 conversion_data[AD7877_NR_SENSE];
>
> struct spi_transfer xfer[AD7877_NR_SENSE + 2];
> struct spi_message msg;
>
>+ struct mutex mutex;
>+ unsigned disabled:1; /* P: mutex */
>+ unsigned gpio3:1; /* P: mutex */
>+ unsigned gpio4:1; /* P: mutex */
>+
> spinlock_t lock;
> struct timer_list timer; /* P: lock */
>- unsigned pendown:1; /* P: lock */
> unsigned pending:1; /* P: lock */
>- unsigned disabled:1;
>- unsigned gpio3:1;
>- unsigned gpio4:1;
> };
>
> static int gpio3;
>+module_param(gpio3, int, 0);
>+MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
>
> /*
> * ad7877_read/write are only used for initial setup and for sysfs
>controls.
>@@ -208,9 +211,10 @@ static int gpio3;
>
> static int ad7877_read(struct spi_device *spi, u16 reg)
> {
>- struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL);
>- int status, ret;
>+ struct ser_req *req;
>+ int status, ret;
>
>+ req = kzalloc(sizeof *req, GFP_KERNEL);
> if (!req)
> return -ENOMEM;
>
>@@ -228,11 +232,8 @@ static int ad7877_read(struct spi_device *spi, u16
>reg)
> spi_message_add_tail(&req->xfer[1], &req->msg);
>
> status = spi_sync(spi, &req->msg);
>+ ret = status ? : req->sample;
>
>- if (status == 0)
>- status = req->msg.status;
>-
>- ret = status ? status : req->sample;
> kfree(req);
>
> return ret;
>@@ -240,9 +241,10 @@ static int ad7877_read(struct spi_device *spi, u16
>reg)
>
> static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
> {
>- struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL);
>- int status;
>+ struct ser_req *req;
>+ int status;
>
>+ req = kzalloc(sizeof *req, GFP_KERNEL);
> if (!req)
> return -ENOMEM;
>
>@@ -256,9 +258,6 @@ static int ad7877_write(struct spi_device *spi, u16
>reg, u16 val)
>
> status = spi_sync(spi, &req->msg);
>
>- if (status == 0)
>- status = req->msg.status;
>-
> kfree(req);
>
> return status;
>@@ -266,12 +265,13 @@ static int ad7877_write(struct spi_device *spi,
u16
>reg, u16 val)
>
> static int ad7877_read_adc(struct spi_device *spi, unsigned command)
> {
>- struct ad7877 *ts = dev_get_drvdata(&spi->dev);
>- struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL);
>- int status;
>- int sample;
>- int i;
>+ struct ad7877 *ts = dev_get_drvdata(&spi->dev);
>+ struct ser_req *req;
>+ int status;
>+ int sample;
>+ int i;
>
>+ req = kzalloc(sizeof *req, GFP_KERNEL);
> if (!req)
> return -ENOMEM;
>
>@@ -314,21 +314,18 @@ static int ad7877_read_adc(struct spi_device
*spi,
>unsigned command)
> spi_message_add_tail(&req->xfer[i], &req->msg);
>
> status = spi_sync(spi, &req->msg);
>-
>- if (status == 0)
>- status = req->msg.status;
>-
> sample = req->sample;
>
> kfree(req);
>- return status ? status : sample;
>+
>+ return status ? : sample;
> }
>
> static void ad7877_rx(struct ad7877 *ts)
> {
>- struct input_dev *input_dev = ts->input;
>- unsigned Rt;
>- u16 x, y, z1, z2;
>+ struct input_dev *input_dev = ts->input;
>+ unsigned Rt;
>+ u16 x, y, z1, z2;
>
> x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
> y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
>@@ -350,10 +347,7 @@ static void ad7877_rx(struct ad7877 *ts)
> Rt = (z2 - z1) * x * ts->x_plate_ohms;
> Rt /= z1;
> Rt = (Rt + 2047) >> 12;
>- } else
>- Rt = 0;
>
>- if (Rt) {
> input_report_abs(input_dev, ABS_X, x);
> input_report_abs(input_dev, ABS_Y, y);
> input_report_abs(input_dev, ABS_PRESSURE, Rt);
>@@ -371,7 +365,7 @@ static inline void ad7877_ts_event_release(struct
>ad7877 *ts)
>
> static void ad7877_timer(unsigned long handle)
> {
>- struct ad7877 *ts = (void *)handle;
>+ struct ad7877 *ts = (void *)handle;
>
> ad7877_ts_event_release(ts);
> }
>@@ -382,78 +376,72 @@ static irqreturn_t ad7877_irq(int irq, void
*handle)
> unsigned long flags;
> int status;
>
>- /* The repeated conversion sequencer controlled by TMR kicked
off too
>fast.
>- * We ignore the last and process the sample sequence currently
in
>the queue
>- * It can't be older than 9.4ms, and we need to avoid that
ts->msg
>- * doesn't get issued twice while in work.
>+ /*
>+ * The repeated conversion sequencer controlled by TMR kicked
off
>+ * too fast. We ignore the last and process the sample sequence
>+ * currently in the queue. It can't be older than 9.4ms, and we
>+ * need to avoid that ts->msg doesn't get issued twice while in
work.
> */
>
> spin_lock_irqsave(&ts->lock, flags);
>- if (ts->pending) {
>- spin_unlock_irqrestore(&ts->lock, flags);
>- return IRQ_HANDLED;
>+ if (!ts->pending) {
>+ ts->pending = 1;
>+
>+ status = spi_async(ts->spi, &ts->msg);
>+ if (status)
>+ dev_err(&ts->spi->dev, "spi_sync --> %d\n",
status);
> }
>- ts->pending = 1;
> spin_unlock_irqrestore(&ts->lock, flags);
>
>- status = spi_async(ts->spi, &ts->msg);
>-
>- if (status)
>- dev_err(&ts->spi->dev, "spi_sync --> %d\n", status);
>-
> return IRQ_HANDLED;
> }
>
> static void ad7877_callback(void *_ts)
> {
> struct ad7877 *ts = _ts;
>- unsigned long flags;
>
>- ad7877_rx(ts);
>+ spin_lock_irq(&ts->lock);
>
>- spin_lock_irqsave(&ts->lock, flags);
>+ ad7877_rx(ts);
> ts->pending = 0;
> mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
>- spin_unlock_irqrestore(&ts->lock, flags);
>+
>+ spin_unlock_irq(&ts->lock);
> }
>
> static void ad7877_disable(struct ad7877 *ts)
> {
>- unsigned long flags;
>-
>- spin_lock_irqsave(&ts->lock, flags);
>- if (ts->disabled) {
>- spin_unlock_irqrestore(&ts->lock, flags);
>- return;
>- }
>+ mutex_lock(&ts->mutex);
>
>- ts->disabled = 1;
>- disable_irq(ts->spi->irq);
>- spin_unlock_irqrestore(&ts->lock, flags);
>+ if (!ts->disabled) {
>+ ts->disabled = 1;
>+ disable_irq(ts->spi->irq);
>
>- while (ts->pending) /* Wait for spi_async callback */
>- msleep(1);
>+ /* Wait for spi_async callback */
>+ while (ts->pending)
>+ msleep(1);
>
>- if (del_timer_sync(&ts->timer))
>- ad7877_ts_event_release(ts);
>+ if (del_timer_sync(&ts->timer))
>+ ad7877_ts_event_release(ts);
>+ }
>
> /* we know the chip's in lowpower mode since we always
> * leave it that way after every request
> */
>+
>+ mutex_unlock(&ts->mutex);
> }
>
> static void ad7877_enable(struct ad7877 *ts)
> {
>- unsigned long flags;
>+ mutex_lock(&ts->mutex);
>
>- spin_lock_irqsave(&ts->lock, flags);
> if (ts->disabled) {
>- spin_unlock_irqrestore(&ts->lock, flags);
>- return;
>+ ts->disabled = 0;
>+ enable_irq(ts->spi->irq);
> }
>- ts->disabled = 0;
>- enable_irq(ts->spi->irq);
>- spin_unlock_irqrestore(&ts->lock, flags);
>+
>+ mutex_unlock(&ts->mutex);
> }
>
> #define SHOW(name) static ssize_t \
>@@ -490,12 +478,11 @@ static ssize_t ad7877_disable_store(struct device
>*dev,
> {
> struct ad7877 *ts = dev_get_drvdata(dev);
> unsigned long val;
>- int ret;
>+ int error;
>
>- ret = strict_strtoul(buf, 10, &val);
>-
>- if (ret)
>- return ret;
>+ error = strict_strtoul(buf, 10, &val);
>+ if (error)
>+ return error;
>
> if (val)
> ad7877_disable(ts);
>@@ -521,16 +508,16 @@ static ssize_t ad7877_dac_store(struct device
*dev,
> {
> struct ad7877 *ts = dev_get_drvdata(dev);
> unsigned long val;
>- int ret;
>-
>- ret = strict_strtoul(buf, 10, &val);
>+ int error;
>
>- if (ret)
>- return ret;
>+ error = strict_strtoul(buf, 10, &val);
>+ if (error)
>+ return error;
>
>+ mutex_lock(&ts->mutex);
> ts->dac = val & 0xFF;
>-
> ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) |
>AD7877_DAC_CONF);
>+ mutex_unlock(&ts->mutex);
>
> return count;
> }
>@@ -551,16 +538,17 @@ static ssize_t ad7877_gpio3_store(struct device
*dev,
> {
> struct ad7877 *ts = dev_get_drvdata(dev);
> unsigned long val;
>- int ret;
>+ int error;
>
>- ret = strict_strtoul(buf, 10, &val);
>- if (ret)
>- return ret;
>+ error = strict_strtoul(buf, 10, &val);
>+ if (error)
>+ return error;
>
>+ mutex_lock(&ts->mutex);
> ts->gpio3 = !!val;
>-
> ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA
|
> (ts->gpio4 << 4) | (ts->gpio3 << 5));
>+ mutex_unlock(&ts->mutex);
>
> return count;
> }
>@@ -581,16 +569,17 @@ static ssize_t ad7877_gpio4_store(struct device
*dev,
> {
> struct ad7877 *ts = dev_get_drvdata(dev);
> unsigned long val;
>- int ret;
>+ int error;
>
>- ret = strict_strtoul(buf, 10, &val);
>- if (ret)
>- return ret;
>+ error = strict_strtoul(buf, 10, &val);
>+ if (error)
>+ return error;
>
>+ mutex_lock(&ts->mutex);
> ts->gpio4 = !!val;
>-
> ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA
|
>- (ts->gpio4 << 4) | (ts->gpio3 << 5));
>+ (ts->gpio4 << 4) | (ts->gpio3 << 5));
>+ mutex_unlock(&ts->mutex);
>
> return count;
> }
>@@ -685,14 +674,10 @@ static int __devinit ad7877_probe(struct
spi_device
>*spi)
> }
>
> ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
>- if (!ts)
>- return -ENOMEM;
>-
>-
> input_dev = input_allocate_device();
>- if (!input_dev) {
>- kfree(ts);
>- return -ENOMEM;
>+ if (!ts || !input_dev) {
>+ err = -ENOMEM;
>+ goto err_free_mem;
> }
>
> dev_set_drvdata(&spi->dev, ts);
>@@ -700,6 +685,7 @@ static int __devinit ad7877_probe(struct spi_device
>*spi)
> ts->input = input_dev;
>
> setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
>+ mutex_init(&ts->mutex);
> spin_lock_init(&ts->lock);
>
> ts->model = pdata->model ? : 7877;
>@@ -713,7 +699,7 @@ static int __devinit ad7877_probe(struct spi_device
>*spi)
> ts->averaging = pdata->averaging;
> ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
>
>- snprintf(ts->phys, sizeof(ts->phys), "%s/inputX",
spi->dev.bus_id);
>+ snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi-
>>dev));
>
> input_dev->name = "AD7877 Touchscreen";
> input_dev->phys = ts->phys;
>@@ -761,30 +747,25 @@ static int __devinit ad7877_probe(struct
spi_device
>*spi)
> }
>
> err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
>-
>- if (gpio3)
>- err |= device_create_file(&spi->dev, &dev_attr_gpio3);
>- else
>- err |= device_create_file(&spi->dev, &dev_attr_aux3);
>-
> if (err)
> goto err_free_irq;
>
>+ err = device_create_file(&spi->dev,
>+ gpio3 ? &dev_attr_gpio3 :
&dev_attr_aux3);
>+ if (err)
>+ goto err_remove_attr_group;
>+
> err = input_register_device(input_dev);
> if (err)
> goto err_remove_attr;
>
>- dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
>-
> return 0;
>
> err_remove_attr:
>+ device_remove_file(&spi->dev,
>+ gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
>+err_remove_attr_group:
> sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
>-
>- if (gpio3)
>- device_remove_file(&spi->dev, &dev_attr_gpio3);
>- else
>- device_remove_file(&spi->dev, &dev_attr_aux3);
> err_free_irq:
> free_irq(spi->irq, ts);
> err_free_mem:
>@@ -798,19 +779,14 @@ static int __devexit ad7877_remove(struct
spi_device
>*spi)
> {
> struct ad7877 *ts = dev_get_drvdata(&spi->dev);
>
>- ad7877_disable(ts);
>-
> sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
>+ device_remove_file(&spi->dev,
>+ gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
>
>- if (gpio3)
>- device_remove_file(&spi->dev, &dev_attr_gpio3);
>- else
>- device_remove_file(&spi->dev, &dev_attr_aux3);
>-
>+ ad7877_disable(ts);
> free_irq(ts->spi->irq, ts);
>
> input_unregister_device(ts->input);
>-
> kfree(ts);
>
> dev_dbg(&spi->dev, "unregistered touchscreen\n");
>@@ -866,10 +842,6 @@ static void __exit ad7877_exit(void)
> }
> module_exit(ad7877_exit);
>
>-module_param(gpio3, int, 0);
>-MODULE_PARM_DESC(gpio3,
>- "If gpio3 is set to 1 AUX3 acts as GPIO3");
>-
> MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
> MODULE_DESCRIPTION("AD7877 touchscreen Driver");
> MODULE_LICENSE("GPL");


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