Input: add Atmel Captouch Button driver
Add I2C driver for Atmel Capacitive Touch Button device. Signed-off-by: Hung-yu Wu <hywu@google.com> Signed-off-by: Grant Grundler <grundler@chromium.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>hifive-unleashed-5.1
Daniel Hung-yu Wu
Dmitry Torokhov
parent
db36ae8516
commit
b06d43f7a3
|
|
@ -0,0 +1,36 @@
|
|||
Device tree bindings for Atmel capacitive touch device, typically
|
||||
an Atmel touch sensor connected to AtmegaXX MCU running firmware
|
||||
based on Qtouch library.
|
||||
|
||||
The node for this device must be a child of a I2C controller node, as the
|
||||
device communicates via I2C.
|
||||
|
||||
Required properties:
|
||||
|
||||
compatible: Must be "atmel,captouch".
|
||||
reg: The I2C slave address of the device.
|
||||
interrupts: Property describing the interrupt line the device
|
||||
is connected to. The device only has one interrupt
|
||||
source.
|
||||
linux,keycodes: Specifies an array of numeric keycode values to
|
||||
be used for reporting button presses. The array can
|
||||
contain up to 8 entries.
|
||||
|
||||
Optional properties:
|
||||
|
||||
autorepeat: Enables the Linux input system's autorepeat
|
||||
feature on the input device.
|
||||
|
||||
Example:
|
||||
|
||||
atmel-captouch@51 {
|
||||
compatible = "atmel,captouch";
|
||||
reg = <0x51>;
|
||||
interrupt-parent = <&tlmm>;
|
||||
interrupts = <67 IRQ_TYPE_EDGE_FALLING>;
|
||||
linux,keycodes = <BTN_0>, <BTN_1>,
|
||||
<BTN_2>, <BTN_3>,
|
||||
<BTN_4>, <BTN_5>,
|
||||
<BTN_6>, <BTN_7>;
|
||||
autorepeat;
|
||||
};
|
||||
|
|
@ -82,6 +82,19 @@ config INPUT_ARIZONA_HAPTICS
|
|||
To compile this driver as a module, choose M here: the
|
||||
module will be called arizona-haptics.
|
||||
|
||||
config INPUT_ATMEL_CAPTOUCH
|
||||
tristate "Atmel Capacitive Touch Button Driver"
|
||||
depends on OF || COMPILE_TEST
|
||||
help
|
||||
Say Y here if an Atmel Capacitive Touch Button device which
|
||||
implements "captouch" protocol is connected to I2C bus. Typically
|
||||
this device consists of Atmel Touch sensor controlled by AtMegaXX
|
||||
MCU running firmware based on Qtouch library.
|
||||
One should find "atmel,captouch" node in the board specific DTS.
|
||||
|
||||
To compile this driver as a module, choose M here: the
|
||||
module will be called atmel_captouch.
|
||||
|
||||
config INPUT_BMA150
|
||||
tristate "BMA150/SMB380 acceleration sensor support"
|
||||
depends on I2C
|
||||
|
|
|
|||
|
|
@ -17,6 +17,7 @@ obj-$(CONFIG_INPUT_APANEL) += apanel.o
|
|||
obj-$(CONFIG_INPUT_ARIZONA_HAPTICS) += arizona-haptics.o
|
||||
obj-$(CONFIG_INPUT_ATI_REMOTE2) += ati_remote2.o
|
||||
obj-$(CONFIG_INPUT_ATLAS_BTNS) += atlas_btns.o
|
||||
obj-$(CONFIG_INPUT_ATMEL_CAPTOUCH) += atmel_captouch.o
|
||||
obj-$(CONFIG_INPUT_BFIN_ROTARY) += bfin_rotary.o
|
||||
obj-$(CONFIG_INPUT_BMA150) += bma150.o
|
||||
obj-$(CONFIG_INPUT_CM109) += cm109.o
|
||||
|
|
|
|||
|
|
@ -0,0 +1,290 @@
|
|||
/*
|
||||
* Atmel Atmegaxx Capacitive Touch Button Driver
|
||||
*
|
||||
* Copyright (C) 2016 Google, inc.
|
||||
*
|
||||
* This software is licensed under the terms of the GNU General Public
|
||||
* License version 2, as published by the Free Software Foundation, and
|
||||
* may be copied, distributed, and modified under those terms.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*/
|
||||
|
||||
/*
|
||||
* It's irrelevant that the HW used to develop captouch driver is based
|
||||
* on Atmega88PA part and uses QtouchADC parts for sensing touch.
|
||||
* Calling this driver "captouch" is an arbitrary way to distinguish
|
||||
* the protocol this driver supported by other atmel/qtouch drivers.
|
||||
*
|
||||
* Captouch driver supports a newer/different version of the I2C
|
||||
* registers/commands than the qt1070.c driver.
|
||||
* Don't let the similarity of the general driver structure fool you.
|
||||
*
|
||||
* For raw i2c access from userspace, use i2cset/i2cget
|
||||
* to poke at /dev/i2c-N devices.
|
||||
*/
|
||||
|
||||
#include <linux/device.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/i2c.h>
|
||||
#include <linux/input.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/slab.h>
|
||||
|
||||
/* Maximum number of buttons supported */
|
||||
#define MAX_NUM_OF_BUTTONS 8
|
||||
|
||||
/* Registers */
|
||||
#define REG_KEY1_THRESHOLD 0x02
|
||||
#define REG_KEY2_THRESHOLD 0x03
|
||||
#define REG_KEY3_THRESHOLD 0x04
|
||||
#define REG_KEY4_THRESHOLD 0x05
|
||||
|
||||
#define REG_KEY1_REF_H 0x20
|
||||
#define REG_KEY1_REF_L 0x21
|
||||
#define REG_KEY2_REF_H 0x22
|
||||
#define REG_KEY2_REF_L 0x23
|
||||
#define REG_KEY3_REF_H 0x24
|
||||
#define REG_KEY3_REF_L 0x25
|
||||
#define REG_KEY4_REF_H 0x26
|
||||
#define REG_KEY4_REF_L 0x27
|
||||
|
||||
#define REG_KEY1_DLT_H 0x30
|
||||
#define REG_KEY1_DLT_L 0x31
|
||||
#define REG_KEY2_DLT_H 0x32
|
||||
#define REG_KEY2_DLT_L 0x33
|
||||
#define REG_KEY3_DLT_H 0x34
|
||||
#define REG_KEY3_DLT_L 0x35
|
||||
#define REG_KEY4_DLT_H 0x36
|
||||
#define REG_KEY4_DLT_L 0x37
|
||||
|
||||
#define REG_KEY_STATE 0x3C
|
||||
|
||||
/*
|
||||
* @i2c_client: I2C slave device client pointer
|
||||
* @input: Input device pointer
|
||||
* @num_btn: Number of buttons
|
||||
* @keycodes: map of button# to KeyCode
|
||||
* @prev_btn: Previous key state to detect button "press" or "release"
|
||||
* @xfer_buf: I2C transfer buffer
|
||||
*/
|
||||
struct atmel_captouch_device {
|
||||
struct i2c_client *client;
|
||||
struct input_dev *input;
|
||||
u32 num_btn;
|
||||
u32 keycodes[MAX_NUM_OF_BUTTONS];
|
||||
u8 prev_btn;
|
||||
u8 xfer_buf[8] ____cacheline_aligned;
|
||||
};
|
||||
|
||||
/*
|
||||
* Read from I2C slave device
|
||||
* The protocol is that the client has to provide both the register address
|
||||
* and the length, and while reading back the device would prepend the data
|
||||
* with address and length for verification.
|
||||
*/
|
||||
static int atmel_read(struct atmel_captouch_device *capdev,
|
||||
u8 reg, u8 *data, size_t len)
|
||||
{
|
||||
struct i2c_client *client = capdev->client;
|
||||
struct device *dev = &client->dev;
|
||||
struct i2c_msg msg[2];
|
||||
int err;
|
||||
|
||||
if (len > sizeof(capdev->xfer_buf) - 2)
|
||||
return -EINVAL;
|
||||
|
||||
capdev->xfer_buf[0] = reg;
|
||||
capdev->xfer_buf[1] = len;
|
||||
|
||||
msg[0].addr = client->addr;
|
||||
msg[0].flags = 0;
|
||||
msg[0].buf = capdev->xfer_buf;
|
||||
msg[0].len = 2;
|
||||
|
||||
msg[1].addr = client->addr;
|
||||
msg[1].flags = I2C_M_RD;
|
||||
msg[1].buf = capdev->xfer_buf;
|
||||
msg[1].len = len + 2;
|
||||
|
||||
err = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
|
||||
if (err != ARRAY_SIZE(msg))
|
||||
return err < 0 ? err : -EIO;
|
||||
|
||||
if (capdev->xfer_buf[0] != reg) {
|
||||
dev_err(dev,
|
||||
"I2C read error: register address does not match (%#02x vs %02x)\n",
|
||||
capdev->xfer_buf[0], reg);
|
||||
return -ECOMM;
|
||||
}
|
||||
|
||||
memcpy(data, &capdev->xfer_buf[2], len);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Handle interrupt and report the key changes to the input system.
|
||||
* Multi-touch can be supported; however, it really depends on whether
|
||||
* the device can multi-touch.
|
||||
*/
|
||||
static irqreturn_t atmel_captouch_isr(int irq, void *data)
|
||||
{
|
||||
struct atmel_captouch_device *capdev = data;
|
||||
struct device *dev = &capdev->client->dev;
|
||||
int error;
|
||||
int i;
|
||||
u8 new_btn;
|
||||
u8 changed_btn;
|
||||
|
||||
error = atmel_read(capdev, REG_KEY_STATE, &new_btn, 1);
|
||||
if (error) {
|
||||
dev_err(dev, "failed to read button state: %d\n", error);
|
||||
goto out;
|
||||
}
|
||||
|
||||
dev_dbg(dev, "%s: button state %#02x\n", __func__, new_btn);
|
||||
|
||||
changed_btn = new_btn ^ capdev->prev_btn;
|
||||
capdev->prev_btn = new_btn;
|
||||
|
||||
for (i = 0; i < capdev->num_btn; i++) {
|
||||
if (changed_btn & BIT(i))
|
||||
input_report_key(capdev->input,
|
||||
capdev->keycodes[i],
|
||||
new_btn & BIT(i));
|
||||
}
|
||||
|
||||
input_sync(capdev->input);
|
||||
|
||||
out:
|
||||
return IRQ_HANDLED;
|
||||
}
|
||||
|
||||
/*
|
||||
* Probe function to setup the device, input system and interrupt
|
||||
*/
|
||||
static int atmel_captouch_probe(struct i2c_client *client,
|
||||
const struct i2c_device_id *id)
|
||||
{
|
||||
struct atmel_captouch_device *capdev;
|
||||
struct device *dev = &client->dev;
|
||||
struct device_node *node;
|
||||
int i;
|
||||
int err;
|
||||
|
||||
if (!i2c_check_functionality(client->adapter,
|
||||
I2C_FUNC_SMBUS_BYTE_DATA |
|
||||
I2C_FUNC_SMBUS_WORD_DATA |
|
||||
I2C_FUNC_SMBUS_I2C_BLOCK)) {
|
||||
dev_err(dev, "needed i2c functionality is not supported\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
capdev = devm_kzalloc(dev, sizeof(*capdev), GFP_KERNEL);
|
||||
if (!capdev)
|
||||
return -ENOMEM;
|
||||
|
||||
capdev->client = client;
|
||||
i2c_set_clientdata(client, capdev);
|
||||
|
||||
err = atmel_read(capdev, REG_KEY_STATE,
|
||||
&capdev->prev_btn, sizeof(capdev->prev_btn));
|
||||
if (err) {
|
||||
dev_err(dev, "failed to read initial button state: %d\n", err);
|
||||
return err;
|
||||
}
|
||||
|
||||
capdev->input = devm_input_allocate_device(dev);
|
||||
if (!capdev->input) {
|
||||
dev_err(dev, "failed to allocate input device\n");
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
capdev->input->id.bustype = BUS_I2C;
|
||||
capdev->input->id.product = 0x880A;
|
||||
capdev->input->id.version = 0;
|
||||
capdev->input->name = "ATMegaXX Capacitive Button Controller";
|
||||
__set_bit(EV_KEY, capdev->input->evbit);
|
||||
|
||||
node = dev->of_node;
|
||||
if (!node) {
|
||||
dev_err(dev, "failed to find matching node in device tree\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (of_property_read_bool(node, "autorepeat"))
|
||||
__set_bit(EV_REP, capdev->input->evbit);
|
||||
|
||||
capdev->num_btn = of_property_count_u32_elems(node, "linux,keymap");
|
||||
if (capdev->num_btn > MAX_NUM_OF_BUTTONS)
|
||||
capdev->num_btn = MAX_NUM_OF_BUTTONS;
|
||||
|
||||
err = of_property_read_u32_array(node, "linux,keycodes",
|
||||
capdev->keycodes,
|
||||
capdev->num_btn);
|
||||
if (err) {
|
||||
dev_err(dev,
|
||||
"failed to read linux,keycode property: %d\n", err);
|
||||
return err;
|
||||
}
|
||||
|
||||
for (i = 0; i < capdev->num_btn; i++)
|
||||
__set_bit(capdev->keycodes[i], capdev->input->keybit);
|
||||
|
||||
capdev->input->keycode = capdev->keycodes;
|
||||
capdev->input->keycodesize = sizeof(capdev->keycodes[0]);
|
||||
capdev->input->keycodemax = capdev->num_btn;
|
||||
|
||||
err = input_register_device(capdev->input);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
err = devm_request_threaded_irq(dev, client->irq,
|
||||
NULL, atmel_captouch_isr,
|
||||
IRQF_ONESHOT,
|
||||
"atmel_captouch", capdev);
|
||||
if (err) {
|
||||
dev_err(dev, "failed to request irq %d: %d\n",
|
||||
client->irq, err);
|
||||
return err;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_OF
|
||||
static const struct of_device_id atmel_captouch_of_id[] = {
|
||||
{
|
||||
.compatible = "atmel,captouch",
|
||||
},
|
||||
{ /* sentinel */ }
|
||||
};
|
||||
MODULE_DEVICE_TABLE(of, atmel_captouch_of_id);
|
||||
#endif
|
||||
|
||||
static const struct i2c_device_id atmel_captouch_id[] = {
|
||||
{ "atmel_captouch", 0 },
|
||||
{ }
|
||||
};
|
||||
MODULE_DEVICE_TABLE(i2c, atmel_captouch_id);
|
||||
|
||||
static struct i2c_driver atmel_captouch_driver = {
|
||||
.probe = atmel_captouch_probe,
|
||||
.id_table = atmel_captouch_id,
|
||||
.driver = {
|
||||
.name = "atmel_captouch",
|
||||
.of_match_table = of_match_ptr(atmel_captouch_of_id),
|
||||
},
|
||||
};
|
||||
module_i2c_driver(atmel_captouch_driver);
|
||||
|
||||
/* Module information */
|
||||
MODULE_AUTHOR("Hung-yu Wu <hywu@google.com>");
|
||||
MODULE_DESCRIPTION("Atmel ATmegaXX Capacitance Touch Sensor I2C Driver");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
Loading…
Reference in New Issue