On Tue, May 17, 2016 at 12:29:32PM -0700, Grant Grundler wrote: > From: Daniel Hung-yu Wu <h...@google.com> > > Add I2C driver for Atmel Capacitive Touch Button device. > > Signed-off-by: Hung-yu Wu <h...@google.com> > Signed-off-by: Grant Grundler <grund...@chromium.org>
Applied, thank you. > --- > drivers/input/misc/Kconfig | 13 ++ > drivers/input/misc/Makefile | 1 + > drivers/input/misc/atmel_captouch.c | 287 > ++++++++++++++++++++++++++++++++++++ > 3 files changed, 299 insertions(+) > create mode 100644 drivers/input/misc/atmel_captouch.c > > V4: wordsmithing comments at top of file. > Added missing semicolon to CONFIG_OF data struct. > > V3: use dash, not underscore in nodename. Wordsmith Kconfig help text. > > V2: split Documentation/devicetree/bindings from driver patch. > rename "atmel,atmegaxx_captouch" to "atmel,captouch" since it's irrelevant > which controller implements the register set/controller. > > V1: posted https://lkml.org/lkml/2016/5/3/613 > > diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig > index 838824b..d8b6620 100644 > --- a/drivers/input/misc/Kconfig > +++ b/drivers/input/misc/Kconfig > @@ -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 > diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile > index f77268e..b5ec626 100644 > --- a/drivers/input/misc/Makefile > +++ b/drivers/input/misc/Makefile > @@ -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 > diff --git a/drivers/input/misc/atmel_captouch.c > b/drivers/input/misc/atmel_captouch.c > new file mode 100644 > index 0000000..91bfc73 > --- /dev/null > +++ b/drivers/input/misc/atmel_captouch.c > @@ -0,0 +1,287 @@ > +/* > + * Atmel 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 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 supports from 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\n"); > + 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 <h...@google.com>"); > +MODULE_DESCRIPTION("Atmel ATmegaXX Capacitance Touch Sensor I2C Driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.1.2 > -- Dmitry
