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Date: Thu, 10 Nov 2011 10:38:07 -0800
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: oskar.andero@...yericsson.com
Cc: linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
jic23@....ac.uk, aghayal@...eaurora.org,
Courtney Cavin <courtney.cavin@...yericsson.com>
Subject: Re: [PATCH] input: add driver support for Sharp gp2ap002a00f
proximity sensor
Hi Oskar, Courtney,
On Thu, Nov 10, 2011 at 05:07:53PM +0100, oskar.andero@...yericsson.com wrote:
> From: Courtney Cavin <courtney.cavin@...yericsson.com>
>
> Signed-off-by: Courtney Cavin <courtney.cavin@...yericsson.com>
> Signed-off-by: Oskar Andero <oskar.andero@...yericsson.com>
The driver looks mostly good, just a few comments below.
> +#include <linux/gp2ap002a00f.h>
Probably should reside in include/linux/input/ or include/linux/i2c/
> +
> +struct gp2a_data {
> + struct input_dev *device;
> + struct gp2a_platform_data *pdata;
const.
> + 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
> +};
> +
> +#define NUM_TRIES 5
> +static int gp2a_write_byte(struct gp2a_data *dt, u8 reg, u8 val)
> +{
> + int error;
> + int n;
> + struct device *dev = &dt->i2c_client->dev;
> +
> + for (n = 0; n < NUM_TRIES; n++) {
> + error = i2c_smbus_write_byte_data(dt->i2c_client, reg, val);
> + if (error < 0)
> + dev_err(dev, "i2c_smbus write failed, %d\n", error);
Do you actually see errors?
> + else
> + return 0;
> + msleep(10);
> + }
> + return error;
> +}
> +
> +static int gp2a_initialize(struct gp2a_data *dt)
__devinit
> +{
> + int error;
> +
> + error = gp2a_write_byte(dt, GP2A_ADDR_GAIN, 0x08);
> + if (error < 0)
> + return error;
> +
> + error = gp2a_write_byte(dt, GP2A_ADDR_HYS, 0xc2);
> + if (error < 0)
> + return error;
> +
> + error = gp2a_write_byte(dt, GP2A_ADDR_CYCLE, 0x04);
> + if (error < 0)
> + return error;
> +
> + error = gp2a_write_byte(dt, GP2A_ADDR_OPMOD, 0x00);
> +
> + return error;
> +}
> +
> +static int gp2a_report(struct gp2a_data *dt)
> +{
> + int vo = gpio_get_value(dt->pdata->gpio);
> +
> + input_report_abs(dt->device, ABS_DISTANCE, vo ? 255 : 0);
This doe snot look like real distance, SW_FRONT_PROXIMITY instead?
> + input_sync(dt->device);
> +
> + return 0;
> +}
> +
> +static irqreturn_t gp2a_irq(int irq, void *dev_id)
> +{
> + struct device *dev = dev_id;
> + struct gp2a_data *dt = dev_get_drvdata(dev);
Prefer to have correct accessor functions, in this case
i2c_get_clientdata().
> +
> + 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_write_byte(dt, GP2A_ADDR_OPMOD, GP2A_CTRL_SSD);
> + if (error < 0) {
> + dev_err(&dev->dev, "Unable to activate, err %d\n", error);
> + return error;
> + }
> +
> + enable_irq(gpio_to_irq(dt->i2c_client->irq));
Are you positive that gpio_to_irq is needed here? Normally i2c client
has proper IRQ number already.
> +
> + if (dt->pdata->wake)
if (device_may_wakeup(&client->dev))
and you need to do
device_init_wakeup(&client->dev, pdata->wake);
in probe().
> + enable_irq_wake(gpio_to_irq(dt->i2c_client->irq));
Usually you enable wakeups in suspend routine instead of only when
device is opened by userspace.
> +
> + gp2a_report(dt);
> +
> + return 0;
> +}
> +
> +static void gp2a_device_close(struct input_dev *dev)
> +{
> + struct gp2a_data *dt = input_get_drvdata(dev);
> + int error;
> +
> + if (dt->pdata->wake)
> + disable_irq_wake(gpio_to_irq(dt->i2c_client->irq));
> +
> + disable_irq(gpio_to_irq(dt->i2c_client->irq));
> + error = gp2a_write_byte(dt, GP2A_ADDR_OPMOD, 0);
> + if (error < 0)
> + dev_err(&dev->dev, "Unable to deactivate, err %d\n", error);
> +}
> +
> +static int gp2a_probe(struct i2c_client *client,
> + const struct i2c_device_id *id);
> +static int gp2a_remove(struct i2c_client *client);
Instead of having forward declarations just move gp2a_i2c_driver
definition further down.
> +
> +static const struct i2c_device_id gp2a_i2c_id[] = {
> + {GP2A_I2C_NAME, 0},
> + {}
> +};
> +
> +static struct i2c_driver gp2a_i2c_driver = {
> + .driver = {
> + .name = GP2A_I2C_NAME,
> + .owner = THIS_MODULE
> + },
> + .probe = gp2a_probe,
> + .remove = __devexit_p(gp2a_remove),
> + .id_table = gp2a_i2c_id
> +};
> +
> +static int gp2a_probe(struct i2c_client *client, const struct i2c_device_id *id)
__devinit
> +{
> + struct gp2a_platform_data *pdata;
const.
> + struct gp2a_data *dt;
> + int error;
> +
> + pdata = client->dev.platform_data;
> + if (!pdata)
> + return -EINVAL;
> +
> + if (pdata->gpio_setup) {
> + error = pdata->gpio_setup();
> + if (error < 0)
> + return error;
> + }
> +
> + error = gpio_direction_input(pdata->gpio);
> + if (error < 0)
> + goto err_gpio_shutdown;
> +
> + dt = kzalloc(sizeof(struct gp2a_data), GFP_KERNEL);
> + if (!dt) {
> + error = -ENOMEM;
> + goto err_gpio_shutdown;
> + }
> +
> + client->driver = &gp2a_i2c_driver;
Shoudl no be needed, i2c core will take care of setting driver for you.
> + 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);
> +
> + dt->device->open = gp2a_device_open;
> + dt->device->close = gp2a_device_close;
> + dt->device->name = GP2A_I2C_NAME;
> + dt->device->id.bustype = BUS_I2C;
> + set_bit(EV_ABS, dt->device->evbit);
__set_bit()
> + set_bit(ABS_DISTANCE, dt->device->absbit);
Not really needed, the call below will take care of this.
> +
> + input_set_abs_params(dt->device, ABS_DISTANCE, 0, 255, 0, 0);
> +
> + error = input_register_device(dt->device);
> + if (error) {
> + dev_err(&dt->device->dev, "device registration failed\n");
> + input_free_device(dt->device);
> + goto err_free_dt;
To avoid dooing partial unwind in error path switch device registration
and request_threaded_irq() around.
> + }
> +
> + error = request_threaded_irq(gpio_to_irq(dt->i2c_client->irq), NULL,
> + gp2a_irq, IRQF_TRIGGER_RISING |
> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> + GP2A_I2C_NAME, &dt->i2c_client->dev);
Why are you passing bare device to the interrupt handler instead of 'dt'
whuch is much more useful.
> + if (error) {
> + dev_err(&dt->device->dev, "irq request failed\n");
> + goto err_unreg_input;
> + }
> + disable_irq(gpio_to_irq(dt->i2c_client->irq));
> +
> + return 0;
> +
> +err_unreg_input:
> + input_unregister_device(dt->device);
> +err_free_dt:
> + kfree(dt);
> +err_gpio_shutdown:
> + if (pdata->gpio_shutdown)
> + pdata->gpio_shutdown();
> + return error;
> +}
> +
> +static int gp2a_remove(struct i2c_client *client)
__devexit
> +{
> + struct gp2a_data *dt = i2c_get_clientdata(client);
> +
> + device_init_wakeup(&client->dev, 0);
> + if (dt->pdata->gpio_shutdown)
> + dt->pdata->gpio_shutdown();
Should it be done last, after unregistering the device? You want to let
close() chance to talk to the device.
> + free_irq(gpio_to_irq(dt->i2c_client->irq), &dt->i2c_client->dev);
> + input_unregister_device(dt->device);
> + kfree(dt);
> +
> + return 0;
> +}
> +
> +static int __init gp2a_init(void)
> +{
> + return i2c_add_driver(&gp2a_i2c_driver);
> +}
> +
> +static void __exit gp2a_exit(void)
> +{
> + i2c_del_driver(&gp2a_i2c_driver);
> +}
> +
> +module_init(gp2a_init);
> +module_exit(gp2a_exit);
> +
> +MODULE_AUTHOR("Courtney Cavin <courtney.cavin@...yericsson.com>");
> +MODULE_DESCRIPTION("Sharp GP2AP002A00F I2C Proximity/Opto sensor driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/gp2ap002a00f.h b/include/linux/gp2ap002a00f.h
> new file mode 100644
> index 0000000..74e2610
> --- /dev/null
> +++ b/include/linux/gp2ap002a00f.h
> @@ -0,0 +1,13 @@
> +#ifndef _GP2AP002A00F_H_
> +#define _GP2AP002A00F_H_
> +
> +#define GP2A_I2C_NAME "gp2ap002a00f"
> +
> +struct gp2a_platform_data {
> + int gpio;
> + int wake;
Bool.
> + int (*gpio_setup)(void);
Woudl be nice to pass client or something to identify the device you are
workig with; otherwise there is no chance of having more than one such
device in a box.
> + int (*gpio_shutdown)(void);
> +};
> +
> +#endif
> --
> 1.7.7
>
--
Dmitry
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