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SubjectRe: [PATCH v2] input: add driver support for Sharp gp2ap002a00f proximity sensor
Hi again Dmitry,

Just a quick question before I post v3.

On 18:03 Mon 14 Nov , Dmitry Torokhov wrote:
> Hi Courtney,
>
> On Mon, Nov 14, 2011 at 04:39:18PM +0100, oskar.andero@sonyericsson.com wrote:
> > From: Courtney Cavin <courtney.cavin@sonyericsson.com>
> >
>
> The driver looks much better, a few more comments still.
>
> > +
> > +#include <linux/i2c.h>
> > +#include <linux/irq.h>
> > +#include <linux/slab.h>
> > +#include <linux/input.h>
> > +#include <linux/module.h>
> > +#include <linux/workqueue.h>
>
> As Shubhrajyoti mentioned workqueue.h is probably not needed.
>
> > +#include <linux/interrupt.h>
> > +#include <linux/gpio.h>
> > +#include <linux/delay.h>
> > +#include <linux/input/gp2ap002a00f.h>
> > +
> > +struct gp2a_data {
> > + struct input_dev *device;
> > + const struct gp2a_platform_data *pdata;
> > + struct i2c_client *i2c_client;
> > +};
> > +
> > +enum gp2a_addr {
> > + GP2A_ADDR_PROX = 0x0,
> > + GP2A_ADDR_GAIN = 0x1,
> > + GP2A_ADDR_HYS = 0x2,
> > + GP2A_ADDR_CYCLE = 0x3,
> > + GP2A_ADDR_OPMOD = 0x4,
> > + GP2A_ADDR_CON = 0x6
> > +};
> > +
> > +enum gp2a_controls {
> > + GP2A_CTRL_SSD = 0x01
> > +};
> > +
> > +static int gp2a_enable(struct gp2a_data *dt)
> > +{
> > + return i2c_smbus_write_byte_data(dt->i2c_client, GP2A_ADDR_OPMOD,
> > + GP2A_CTRL_SSD);
> > +}
> > +
> > +static int gp2a_disable(struct gp2a_data *dt)
> > +{
> > + return i2c_smbus_write_byte_data(dt->i2c_client, GP2A_ADDR_OPMOD,
> > + 0x00);
> > +}
> > +
> > +static int __devinit gp2a_initialize(struct gp2a_data *dt)
> > +{
> > + int error;
> > +
> > + error = i2c_smbus_write_byte_data(dt->i2c_client, GP2A_ADDR_GAIN,
> > + 0x08);
> > + if (error < 0)
> > + return error;
> > +
> > + error = i2c_smbus_write_byte_data(dt->i2c_client, GP2A_ADDR_HYS,
> > + 0xc2);
> > + if (error < 0)
> > + return error;
> > +
> > + error = i2c_smbus_write_byte_data(dt->i2c_client, GP2A_ADDR_CYCLE,
> > + 0x04);
> > + if (error < 0)
> > + return error;
> > +
> > + error = gp2a_disable(dt);
> > +
> > + return error;
> > +}
> > +
> > +static int gp2a_report(struct gp2a_data *dt)
> > +{
> > + int vo = gpio_get_value(dt->pdata->vout_gpio);
> > +
> > + input_report_key(dt->device, SW_FRONT_PROXIMITY, !vo);
>
> Switch is not a key, so please use input_report_switch().
>
> > + input_sync(dt->device);
> > +
> > + return 0;
> > +}
> > +
> > +static irqreturn_t gp2a_irq(int irq, void *handle)
> > +{
> > + struct gp2a_data *dt = handle;
> > +
> > + gp2a_report(dt);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static int gp2a_device_open(struct input_dev *dev)
> > +{
> > + struct gp2a_data *dt = input_get_drvdata(dev);
> > + int error;
> > +
> > + error = gp2a_enable(dt);
> > + if (error < 0) {
> > + dev_err(&dev->dev, "unable to activate, err %d\n", error);
> > + return error;
> > + }
> > +
> > + gp2a_report(dt);
> > +
> > + return 0;
> > +}
> > +
> > +static void gp2a_device_close(struct input_dev *dev)
> > +{
> > + struct gp2a_data *dt = input_get_drvdata(dev);
> > + int error;
> > +
> > + error = gp2a_disable(dt);
> > + if (error < 0)
> > + dev_err(&dev->dev, "unable to deactivate, err %d\n", error);
> > +}
> > +
> > +static int __devinit gp2a_probe(struct i2c_client *client,
> > + const struct i2c_device_id *id)
> > +{
> > + const struct gp2a_platform_data *pdata;
> > + struct gp2a_data *dt;
> > + int error;
> > +
> > + pdata = client->dev.platform_data;
> > + if (!pdata)
> > + return -EINVAL;
> > +
> > + if (pdata->hw_setup) {
> > + error = pdata->hw_setup(client);
> > + if (error < 0)
> > + return error;
> > + }
> > +
> > + error = gpio_direction_input(pdata->vout_gpio);
> > + if (error < 0)
> > + goto err_hw_shutdown;
> > +
> > + dt = kzalloc(sizeof(struct gp2a_data), GFP_KERNEL);
> > + if (!dt) {
> > + error = -ENOMEM;
> > + goto err_hw_shutdown;
> > + }
> > +
> > + dt->pdata = pdata;
> > + dt->i2c_client = client;
> > + i2c_set_clientdata(client, dt);
> > +
> > + error = gp2a_initialize(dt);
> > + if (error < 0)
> > + goto err_free_dt;
> > +
> > + dt->device = input_allocate_device();
> > + if (!dt->device) {
> > + error = -ENOMEM;
> > + goto err_free_dt;
> > + }
> > + input_set_drvdata(dt->device, dt);
> > +
> > + error = request_threaded_irq(client->irq, NULL,
> > + gp2a_irq, IRQF_TRIGGER_RISING |
> > + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> > + GP2A_I2C_NAME, dt);
> > + if (error) {
> > + dev_err(&dt->device->dev, "irq request failed\n");
>
> You are leaking dt->device here. Please add a separate label for
> input_free_device(dt->device).
>
> > + goto err_free_dt;
> > + }
> > +
> > + dt->device->open = gp2a_device_open;
> > + dt->device->close = gp2a_device_close;
> > + dt->device->name = GP2A_I2C_NAME;
> > + dt->device->id.bustype = BUS_I2C;
> > +
> > + input_set_capability(dt->device, EV_KEY, SW_FRONT_PROXIMITY);
>
> Should be EV_SW instead of EV_KEY.
>
> > +
> > + error = input_register_device(dt->device);
> > + if (error) {
> > + dev_err(&dt->device->dev, "device registration failed\n");
> > + input_free_device(dt->device);
>
> If you swap request_threaded_irq() and input_register_device() so that
> registration is the last action error handling will be much simpler.
>

I am getting a bit confused here, since you asked me to swap the order
of request_threaded_irq() and input_register_device() in my previous
version as well. Swapping again will take us back to square one or maybe
I am misinterpreting your comment?

Anyways, this is what I am planning to do for v3:

error = input_register_device(dt->device);
if (error) {
...
goto err_free_dt;
}
...
error = request_threaded_irq(client->irq, NULL, ...
if (error) {
...
goto err_free_unregister;
}
...
err_free_unregister:
input_unregister_device(dt->device);
err_free_dt:
kfree(dt);
err_hw_shutdown:
if (pdata->hw_shutdown)
pdata->hw_shutdown(client);
return error;
The above takes care of the leaking input_device and keeps the error handling
pretty compact.
Does this sound reasonable?

-Oskar


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