Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Daniel Hung-yu Wu | 1115 | 99.73% | 1 | 33.33% |
Thomas Gleixner | 2 | 0.18% | 1 | 33.33% |
Uwe Kleine-König | 1 | 0.09% | 1 | 33.33% |
Total | 1118 | 3 |
// SPDX-License-Identifier: GPL-2.0-only /* * Atmel Atmegaxx Capacitive Touch Button Driver * * Copyright (C) 2016 Google, inc. */ /* * 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) { 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; 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; } static const struct of_device_id atmel_captouch_of_id[] = { { .compatible = "atmel,captouch", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, atmel_captouch_of_id); 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 = 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");
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