linux/drivers/input/misc/pcf8574_keypad.c
Uwe Kleine-König ed5c2f5fd1 i2c: Make remove callback return void
The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-08-16 12:46:26 +02:00

222 lines
4.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for a keypad w/16 buttons connected to a PCF8574 I2C I/O expander
*
* Copyright 2005-2008 Analog Devices Inc.
*/
#include <linux/module.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#define DRV_NAME "pcf8574_keypad"
static const unsigned char pcf8574_kp_btncode[] = {
[0] = KEY_RESERVED,
[1] = KEY_ENTER,
[2] = KEY_BACKSLASH,
[3] = KEY_0,
[4] = KEY_RIGHTBRACE,
[5] = KEY_C,
[6] = KEY_9,
[7] = KEY_8,
[8] = KEY_7,
[9] = KEY_B,
[10] = KEY_6,
[11] = KEY_5,
[12] = KEY_4,
[13] = KEY_A,
[14] = KEY_3,
[15] = KEY_2,
[16] = KEY_1
};
struct kp_data {
unsigned short btncode[ARRAY_SIZE(pcf8574_kp_btncode)];
struct input_dev *idev;
struct i2c_client *client;
char name[64];
char phys[32];
unsigned char laststate;
};
static short read_state(struct kp_data *lp)
{
unsigned char x, y, a, b;
i2c_smbus_write_byte(lp->client, 240);
x = 0xF & (~(i2c_smbus_read_byte(lp->client) >> 4));
i2c_smbus_write_byte(lp->client, 15);
y = 0xF & (~i2c_smbus_read_byte(lp->client));
for (a = 0; x > 0; a++)
x = x >> 1;
for (b = 0; y > 0; b++)
y = y >> 1;
return ((a - 1) * 4) + b;
}
static irqreturn_t pcf8574_kp_irq_handler(int irq, void *dev_id)
{
struct kp_data *lp = dev_id;
unsigned char nextstate = read_state(lp);
if (lp->laststate != nextstate) {
int key_down = nextstate < ARRAY_SIZE(lp->btncode);
unsigned short keycode = key_down ?
lp->btncode[nextstate] : lp->btncode[lp->laststate];
input_report_key(lp->idev, keycode, key_down);
input_sync(lp->idev);
lp->laststate = nextstate;
}
return IRQ_HANDLED;
}
static int pcf8574_kp_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
int i, ret;
struct input_dev *idev;
struct kp_data *lp;
if (i2c_smbus_write_byte(client, 240) < 0) {
dev_err(&client->dev, "probe: write fail\n");
return -ENODEV;
}
lp = kzalloc(sizeof(*lp), GFP_KERNEL);
if (!lp)
return -ENOMEM;
idev = input_allocate_device();
if (!idev) {
dev_err(&client->dev, "Can't allocate input device\n");
ret = -ENOMEM;
goto fail_allocate;
}
lp->idev = idev;
lp->client = client;
idev->evbit[0] = BIT_MASK(EV_KEY);
idev->keycode = lp->btncode;
idev->keycodesize = sizeof(lp->btncode[0]);
idev->keycodemax = ARRAY_SIZE(lp->btncode);
for (i = 0; i < ARRAY_SIZE(pcf8574_kp_btncode); i++) {
if (lp->btncode[i] <= KEY_MAX) {
lp->btncode[i] = pcf8574_kp_btncode[i];
__set_bit(lp->btncode[i], idev->keybit);
}
}
__clear_bit(KEY_RESERVED, idev->keybit);
sprintf(lp->name, DRV_NAME);
sprintf(lp->phys, "kp_data/input0");
idev->name = lp->name;
idev->phys = lp->phys;
idev->id.bustype = BUS_I2C;
idev->id.vendor = 0x0001;
idev->id.product = 0x0001;
idev->id.version = 0x0100;
lp->laststate = read_state(lp);
ret = request_threaded_irq(client->irq, NULL, pcf8574_kp_irq_handler,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
DRV_NAME, lp);
if (ret) {
dev_err(&client->dev, "IRQ %d is not free\n", client->irq);
goto fail_free_device;
}
ret = input_register_device(idev);
if (ret) {
dev_err(&client->dev, "input_register_device() failed\n");
goto fail_free_irq;
}
i2c_set_clientdata(client, lp);
return 0;
fail_free_irq:
free_irq(client->irq, lp);
fail_free_device:
input_free_device(idev);
fail_allocate:
kfree(lp);
return ret;
}
static void pcf8574_kp_remove(struct i2c_client *client)
{
struct kp_data *lp = i2c_get_clientdata(client);
free_irq(client->irq, lp);
input_unregister_device(lp->idev);
kfree(lp);
}
#ifdef CONFIG_PM
static int pcf8574_kp_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
enable_irq(client->irq);
return 0;
}
static int pcf8574_kp_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
disable_irq(client->irq);
return 0;
}
static const struct dev_pm_ops pcf8574_kp_pm_ops = {
.suspend = pcf8574_kp_suspend,
.resume = pcf8574_kp_resume,
};
#else
# define pcf8574_kp_resume NULL
# define pcf8574_kp_suspend NULL
#endif
static const struct i2c_device_id pcf8574_kp_id[] = {
{ DRV_NAME, 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pcf8574_kp_id);
static struct i2c_driver pcf8574_kp_driver = {
.driver = {
.name = DRV_NAME,
#ifdef CONFIG_PM
.pm = &pcf8574_kp_pm_ops,
#endif
},
.probe = pcf8574_kp_probe,
.remove = pcf8574_kp_remove,
.id_table = pcf8574_kp_id,
};
module_i2c_driver(pcf8574_kp_driver);
MODULE_AUTHOR("Michael Hennerich");
MODULE_DESCRIPTION("Keypad input driver for 16 keys connected to PCF8574");
MODULE_LICENSE("GPL");