On Sun, Feb 24, 2013 at 10:58:00AM +0100, Heiko Stübner wrote:
> Hi Dmitry,
> 
> Am Sonntag, 24. Februar 2013, 09:00:15 schrieb Dmitry Torokhov:
> > Hi Heiko,
> > 
> > On Sat, Feb 23, 2013 at 12:58:16PM +0100, Heiko Stübner wrote:
> > > +static struct auo_pixcir_ts_platdata *auo_pixcir_parse_dt(struct device
> > > *dev) +{
> > > + struct auo_pixcir_ts_platdata *pdata = NULL;
> > > +
> > > +#ifdef CONFIG_OF
> > > + struct device_node *np = dev->of_node;
> > > +
> > > + if (!np)
> > > +         return NULL;
> > > +
> > > + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> > > + if (!pdata) {
> > > +         dev_err(dev, "failed to allocate platform data\n");
> > > +         return NULL;
> > > + }
> > 
> > I disike #ifdefs in the middle of the code, also it would be nice if we
> > signal the proper error instead of always using -EINVAL when there are
> > issues with platform/DT data.
> > 
> > How about the version of the patch below?
> 
> I tested it and everything of course still works :-) .

OK, great, then I will queue these for the next merge window.

Could you also try this patch (it however needs attached patch enhancing
devres to support custom actions).

Thanks.

-- 
Dmitry

Input: auo-pixer-ts - switch to using managed resources

From: Dmitry Torokhov <[email protected]>

This simplifier error unwinding and device teardown.

Signed-off-by: Dmitry Torokhov <[email protected]>
---
 drivers/input/touchscreen/auo-pixcir-ts.c |  162 ++++++++++++-----------------
 1 file changed, 68 insertions(+), 94 deletions(-)

diff --git a/drivers/input/touchscreen/auo-pixcir-ts.c 
b/drivers/input/touchscreen/auo-pixcir-ts.c
index dfa6d54..f4ba6ffa 100644
--- a/drivers/input/touchscreen/auo-pixcir-ts.c
+++ b/drivers/input/touchscreen/auo-pixcir-ts.c
@@ -533,13 +533,21 @@ static struct auo_pixcir_ts_platdata 
*auo_pixcir_parse_dt(struct device *dev)
 }
 #endif
 
+static void auo_pixcir_reset(void *data)
+{
+       struct auo_pixcir_ts *ts = data;
+
+       gpio_set_value(ts->pdata->gpio_rst, 0);
+}
+
 static int auo_pixcir_probe(struct i2c_client *client,
-                                     const struct i2c_device_id *id)
+                           const struct i2c_device_id *id)
 {
        const struct auo_pixcir_ts_platdata *pdata;
        struct auo_pixcir_ts *ts;
        struct input_dev *input_dev;
-       int ret;
+       int version;
+       int error;
 
        pdata = dev_get_platdata(&client->dev);
        if (!pdata) {
@@ -548,60 +556,30 @@ static int auo_pixcir_probe(struct i2c_client *client,
                        return PTR_ERR(pdata);
        }
 
-       ts = kzalloc(sizeof(struct auo_pixcir_ts), GFP_KERNEL);
+       ts = devm_kzalloc(&client->dev,
+                         sizeof(struct auo_pixcir_ts), GFP_KERNEL);
        if (!ts)
                return -ENOMEM;
 
-       ret = gpio_request(pdata->gpio_int, "auo_pixcir_ts_int");
-       if (ret) {
-               dev_err(&client->dev, "request of gpio %d failed, %d\n",
-                       pdata->gpio_int, ret);
-               goto err_gpio_int;
-       }
-
-       ret = gpio_direction_input(pdata->gpio_int);
-       if (ret) {
-               dev_err(&client->dev, "setting direction of gpio %d failed 
%d\n",
-                       pdata->gpio_int, ret);
-               goto err_gpio_dir;
-       }
-
-       ret = gpio_request(pdata->gpio_rst, "auo_pixcir_ts_rst");
-       if (ret) {
-               dev_err(&client->dev, "request of gpio %d failed, %d\n",
-                       pdata->gpio_rst, ret);
-               goto err_gpio_dir;
-       }
-
-       ret = gpio_direction_output(pdata->gpio_rst, 1);
-       if (ret) {
-               dev_err(&client->dev, "setting direction of gpio %d failed 
%d\n",
-                       pdata->gpio_rst, ret);
-               goto err_gpio_rst;
+       input_dev = devm_input_allocate_device(&client->dev);
+       if (!input_dev) {
+               dev_err(&client->dev, "could not allocate input device\n");
+               return -ENOMEM;
        }
 
-       msleep(200);
-
        ts->pdata = pdata;
        ts->client = client;
+       ts->input = input_dev;
        ts->touch_ind_mode = 0;
+       ts->stopped = true;
        init_waitqueue_head(&ts->wait);
 
        snprintf(ts->phys, sizeof(ts->phys),
                 "%s/input0", dev_name(&client->dev));
 
-       input_dev = input_allocate_device();
-       if (!input_dev) {
-               dev_err(&client->dev, "could not allocate input device\n");
-               goto err_input_alloc;
-       }
-
-       ts->input = input_dev;
-
        input_dev->name = "AUO-Pixcir touchscreen";
        input_dev->phys = ts->phys;
        input_dev->id.bustype = BUS_I2C;
-       input_dev->dev.parent = &client->dev;
 
        input_dev->open = auo_pixcir_input_open;
        input_dev->close = auo_pixcir_input_close;
@@ -626,72 +604,69 @@ static int auo_pixcir_probe(struct i2c_client *client,
                             AUO_PIXCIR_MAX_AREA, 0, 0);
        input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
 
-       ret = i2c_smbus_read_byte_data(client, AUO_PIXCIR_REG_VERSION);
-       if (ret < 0)
-               goto err_fw_vers;
-       dev_info(&client->dev, "firmware version 0x%X\n", ret);
-
-       ret = auo_pixcir_int_config(ts, pdata->int_setting);
-       if (ret)
-               goto err_fw_vers;
-
        input_set_drvdata(ts->input, ts);
-       ts->stopped = true;
 
-       ret = request_threaded_irq(client->irq, NULL, auo_pixcir_interrupt,
-                                  IRQF_TRIGGER_RISING | IRQF_ONESHOT,
-                                  input_dev->name, ts);
-       if (ret) {
-               dev_err(&client->dev, "irq %d requested failed\n", client->irq);
-               goto err_fw_vers;
+       error = devm_gpio_request_one(&client->dev, pdata->gpio_int,
+                                     GPIOF_DIR_IN, "auo_pixcir_ts_int");
+       if (error) {
+               dev_err(&client->dev, "request of gpio %d failed, %d\n",
+                       pdata->gpio_int, error);
+               return error;
        }
 
-       /* stop device and put it into deep sleep until it is opened */
-       ret = auo_pixcir_stop(ts);
-       if (ret < 0)
-               goto err_input_register;
-
-       ret = input_register_device(input_dev);
-       if (ret) {
-               dev_err(&client->dev, "could not register input device\n");
-               goto err_input_register;
+       error = devm_gpio_request_one(&client->dev, pdata->gpio_rst,
+                                     GPIOF_DIR_OUT | GPIOF_INIT_HIGH,
+                                     "auo_pixcir_ts_int");
+       if (error) {
+               dev_err(&client->dev, "request of gpio %d failed, %d\n",
+                       pdata->gpio_rst, error);
+               return error;
        }
 
-       i2c_set_clientdata(client, ts);
-
-       return 0;
-
-err_input_register:
-       free_irq(client->irq, ts);
-err_fw_vers:
-       input_free_device(input_dev);
-err_input_alloc:
-       gpio_set_value(pdata->gpio_rst, 0);
-err_gpio_rst:
-       gpio_free(pdata->gpio_rst);
-err_gpio_dir:
-       gpio_free(pdata->gpio_int);
-err_gpio_int:
-       kfree(ts);
+       error = devm_add_action(&client->dev, auo_pixcir_reset, ts);
+       if (error) {
+               auo_pixcir_reset(ts);
+               dev_err(&client->dev, "failed to register xxx action, %d\n",
+                       error);
+               return error;
+       }
 
-       return ret;
-}
+       msleep(200);
 
-static int auo_pixcir_remove(struct i2c_client *client)
-{
-       struct auo_pixcir_ts *ts = i2c_get_clientdata(client);
-       const struct auo_pixcir_ts_platdata *pdata = ts->pdata;
+       version = i2c_smbus_read_byte_data(client, AUO_PIXCIR_REG_VERSION);
+       if (version < 0) {
+               error = version;
+               return error;
+       }
 
-       free_irq(client->irq, ts);
+       dev_info(&client->dev, "firmware version 0x%X\n", version);
 
-       input_unregister_device(ts->input);
+       error = auo_pixcir_int_config(ts, pdata->int_setting);
+       if (error)
+               return error;
 
-       gpio_set_value(pdata->gpio_rst, 0);
-       gpio_free(pdata->gpio_rst);
+       error = request_threaded_irq(client->irq, NULL, auo_pixcir_interrupt,
+                                    IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+                                    input_dev->name, ts);
+       if (error) {
+               dev_err(&client->dev, "irq %d requested failed, %d\n",
+                       client->irq, error);
+               return error;
+       }
 
-       gpio_free(pdata->gpio_int);
+       /* stop device and put it into deep sleep until it is opened */
+       error = auo_pixcir_stop(ts);
+       if (error)
+               return error;
+
+       error = input_register_device(input_dev);
+       if (error) {
+               dev_err(&client->dev, "could not register input device, %d\n",
+                       error);
+               return error;
+       }
 
-       kfree(ts);
+       i2c_set_clientdata(client, ts);
 
        return 0;
 }
@@ -718,7 +693,6 @@ static struct i2c_driver auo_pixcir_driver = {
                .of_match_table = of_match_ptr(auo_pixcir_ts_dt_idtable),
        },
        .probe          = auo_pixcir_probe,
-       .remove         = auo_pixcir_remove,
        .id_table       = auo_pixcir_idtable,
 };
 
devres: allow adding custom actions to the stack

From: Dmitry Torokhov <[email protected]>

Sometimes drivers need to execute one-off actions in their error handling
or device teardown paths. An example would be toggling a GPIO line to
reset the controlled device into predefined state.

To allow performing such actions when using managed resources let's allow
adding them to stack/group of devres resources.

Signed-off-by: Dmitry Torokhov <[email protected]>
---
 drivers/base/devres.c  |   74 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/device.h |    4 +++
 2 files changed, 78 insertions(+)

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index 6683906..507379e 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -671,6 +671,80 @@ int devres_release_group(struct device *dev, void *id)
 EXPORT_SYMBOL_GPL(devres_release_group);
 
 /*
+ * Custom devres actions allow inserting a simple function call
+ * into the teadown sequence.
+ */
+
+struct action_devres {
+       void *data;
+       void (*action)(void *);
+};
+
+static int devm_action_match(struct device *dev, void *res, void *p)
+{
+       struct action_devres *devres = res;
+       struct action_devres *target = p;
+
+       return devres->action == target->action &&
+              devres->data == target->data;
+}
+
+static void devm_action_release(struct device *dev, void *res)
+{
+       struct action_devres *devres = res;
+
+       devres->action(devres->data);
+}
+
+/**
+ * devm_add_action() - add a custom action to list of managed resources
+ * @dev: Device that owns the action
+ * @action: Function that should be called
+ * @data: Pointer to data passed to @action implementation
+ *
+ * This adds a custom action to the list of managed resources so that
+ * it gets executed as part of standard resource unwinding.
+ */
+int devm_add_action(struct device *dev, void (*action)(void *), void *data)
+{
+       struct action_devres *devres;
+
+       devres = devres_alloc(devm_action_release,
+                             sizeof(struct action_devres), GFP_KERNEL);
+       if (!devres)
+               return -ENOMEM;
+
+       devres->data = data;
+       devres->action = action;
+
+       devres_add(dev, devres);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(devm_add_action);
+
+/**
+ * devm_remove_action() - removes previously added custom action
+ * @dev: Device that owns the action
+ * @action: Function implementing the action
+ * @data: Pointer to data passed to @action implementation
+ *
+ * Removes instance of @action previously added by devm_add_action().
+ * Both action and data should match one of the existing entries.
+ */
+void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
+{
+       struct action_devres devres = {
+               .data = data,
+               .action = action,
+       };
+
+       WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
+                              &devres));
+
+}
+EXPORT_SYMBOL_GPL(devm_remove_action);
+
+/*
  * Managed kzalloc/kfree
  */
 static void devm_kzalloc_release(struct device *dev, void *res)
diff --git a/include/linux/device.h b/include/linux/device.h
index 2fbf088..ba7c802 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -578,6 +578,10 @@ extern void devm_kfree(struct device *dev, void *p);
 void __iomem *devm_request_and_ioremap(struct device *dev,
                        struct resource *res);
 
+/* allows to add/remove a custom action to devres stack */
+int devm_add_action(struct device *dev, void (*action)(void *), void *data);
+void devm_remove_action(struct device *dev, void (*action)(void *), void 
*data);
+
 struct device_dma_parameters {
        /*
         * a low level driver may set these to teach IOMMU code about
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