diff options
Diffstat (limited to 'drivers/input/keyboard/mpr121_touchkey.c')
| -rw-r--r-- | drivers/input/keyboard/mpr121_touchkey.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/drivers/input/keyboard/mpr121_touchkey.c b/drivers/input/keyboard/mpr121_touchkey.c new file mode 100644 index 000000000..3aa2ec45b --- /dev/null +++ b/drivers/input/keyboard/mpr121_touchkey.c @@ -0,0 +1,319 @@ +/* + * Touchkey driver for Freescale MPR121 Controllor + * + * Copyright (C) 2011 Freescale Semiconductor, Inc. + * Author: Zhang Jiejing <jiejing.zhang@freescale.com> + * + * Based on mcs_touchkey.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/module.h> +#include <linux/input.h> +#include <linux/i2c.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/bitops.h> +#include <linux/interrupt.h> +#include <linux/i2c/mpr121_touchkey.h> + +/* Register definitions */ +#define ELE_TOUCH_STATUS_0_ADDR 0x0 +#define ELE_TOUCH_STATUS_1_ADDR 0X1 +#define MHD_RISING_ADDR 0x2b +#define NHD_RISING_ADDR 0x2c +#define NCL_RISING_ADDR 0x2d +#define FDL_RISING_ADDR 0x2e +#define MHD_FALLING_ADDR 0x2f +#define NHD_FALLING_ADDR 0x30 +#define NCL_FALLING_ADDR 0x31 +#define FDL_FALLING_ADDR 0x32 +#define ELE0_TOUCH_THRESHOLD_ADDR 0x41 +#define ELE0_RELEASE_THRESHOLD_ADDR 0x42 +#define AFE_CONF_ADDR 0x5c +#define FILTER_CONF_ADDR 0x5d + +/* + * ELECTRODE_CONF_ADDR: This register configures the number of + * enabled capacitance sensing inputs and its run/suspend mode. + */ +#define ELECTRODE_CONF_ADDR 0x5e +#define ELECTRODE_CONF_QUICK_CHARGE 0x80 +#define AUTO_CONFIG_CTRL_ADDR 0x7b +#define AUTO_CONFIG_USL_ADDR 0x7d +#define AUTO_CONFIG_LSL_ADDR 0x7e +#define AUTO_CONFIG_TL_ADDR 0x7f + +/* Threshold of touch/release trigger */ +#define TOUCH_THRESHOLD 0x08 +#define RELEASE_THRESHOLD 0x05 +/* Masks for touch and release triggers */ +#define TOUCH_STATUS_MASK 0xfff +/* MPR121 has 12 keys */ +#define MPR121_MAX_KEY_COUNT 12 + +struct mpr121_touchkey { + struct i2c_client *client; + struct input_dev *input_dev; + unsigned int key_val; + unsigned int statusbits; + unsigned int keycount; + u16 keycodes[MPR121_MAX_KEY_COUNT]; +}; + +struct mpr121_init_register { + int addr; + u8 val; +}; + +static const struct mpr121_init_register init_reg_table[] = { + { MHD_RISING_ADDR, 0x1 }, + { NHD_RISING_ADDR, 0x1 }, + { MHD_FALLING_ADDR, 0x1 }, + { NHD_FALLING_ADDR, 0x1 }, + { NCL_FALLING_ADDR, 0xff }, + { FDL_FALLING_ADDR, 0x02 }, + { FILTER_CONF_ADDR, 0x04 }, + { AFE_CONF_ADDR, 0x0b }, + { AUTO_CONFIG_CTRL_ADDR, 0x0b }, +}; + +static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id) +{ + struct mpr121_touchkey *mpr121 = dev_id; + struct i2c_client *client = mpr121->client; + struct input_dev *input = mpr121->input_dev; + unsigned int key_num, key_val, pressed; + int reg; + + reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR); + if (reg < 0) { + dev_err(&client->dev, "i2c read error [%d]\n", reg); + goto out; + } + + reg <<= 8; + reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR); + if (reg < 0) { + dev_err(&client->dev, "i2c read error [%d]\n", reg); + goto out; + } + + reg &= TOUCH_STATUS_MASK; + /* use old press bit to figure out which bit changed */ + key_num = ffs(reg ^ mpr121->statusbits) - 1; + pressed = reg & (1 << key_num); + mpr121->statusbits = reg; + + key_val = mpr121->keycodes[key_num]; + + input_event(input, EV_MSC, MSC_SCAN, key_num); + input_report_key(input, key_val, pressed); + input_sync(input); + + dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val, + pressed ? "pressed" : "released"); + +out: + return IRQ_HANDLED; +} + +static int mpr121_phys_init(const struct mpr121_platform_data *pdata, + struct mpr121_touchkey *mpr121, + struct i2c_client *client) +{ + const struct mpr121_init_register *reg; + unsigned char usl, lsl, tl, eleconf; + int i, t, vdd, ret; + + /* Set up touch/release threshold for ele0-ele11 */ + for (i = 0; i <= MPR121_MAX_KEY_COUNT; i++) { + t = ELE0_TOUCH_THRESHOLD_ADDR + (i * 2); + ret = i2c_smbus_write_byte_data(client, t, TOUCH_THRESHOLD); + if (ret < 0) + goto err_i2c_write; + ret = i2c_smbus_write_byte_data(client, t + 1, + RELEASE_THRESHOLD); + if (ret < 0) + goto err_i2c_write; + } + + /* Set up init register */ + for (i = 0; i < ARRAY_SIZE(init_reg_table); i++) { + reg = &init_reg_table[i]; + ret = i2c_smbus_write_byte_data(client, reg->addr, reg->val); + if (ret < 0) + goto err_i2c_write; + } + + + /* + * Capacitance on sensing input varies and needs to be compensated. + * The internal MPR121-auto-configuration can do this if it's + * registers are set properly (based on pdata->vdd_uv). + */ + vdd = pdata->vdd_uv / 1000; + usl = ((vdd - 700) * 256) / vdd; + lsl = (usl * 65) / 100; + tl = (usl * 90) / 100; + ret = i2c_smbus_write_byte_data(client, AUTO_CONFIG_USL_ADDR, usl); + ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_LSL_ADDR, lsl); + ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_TL_ADDR, tl); + + /* + * Quick charge bit will let the capacitive charge to ready + * state quickly, or the buttons may not function after system + * boot. + */ + eleconf = mpr121->keycount | ELECTRODE_CONF_QUICK_CHARGE; + ret |= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, + eleconf); + if (ret != 0) + goto err_i2c_write; + + dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount); + + return 0; + +err_i2c_write: + dev_err(&client->dev, "i2c write error: %d\n", ret); + return ret; +} + +static int mpr_touchkey_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + const struct mpr121_platform_data *pdata = + dev_get_platdata(&client->dev); + struct mpr121_touchkey *mpr121; + struct input_dev *input_dev; + int error; + int i; + + if (!pdata) { + dev_err(&client->dev, "no platform data defined\n"); + return -EINVAL; + } + + if (!pdata->keymap || !pdata->keymap_size) { + dev_err(&client->dev, "missing keymap data\n"); + return -EINVAL; + } + + if (pdata->keymap_size > MPR121_MAX_KEY_COUNT) { + dev_err(&client->dev, "too many keys defined\n"); + return -EINVAL; + } + + if (!client->irq) { + dev_err(&client->dev, "irq number should not be zero\n"); + return -EINVAL; + } + + mpr121 = devm_kzalloc(&client->dev, sizeof(*mpr121), + GFP_KERNEL); + if (!mpr121) + return -ENOMEM; + + input_dev = devm_input_allocate_device(&client->dev); + if (!input_dev) + return -ENOMEM; + + mpr121->client = client; + mpr121->input_dev = input_dev; + mpr121->keycount = pdata->keymap_size; + + input_dev->name = "Freescale MPR121 Touchkey"; + input_dev->id.bustype = BUS_I2C; + input_dev->dev.parent = &client->dev; + input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP); + + input_dev->keycode = mpr121->keycodes; + input_dev->keycodesize = sizeof(mpr121->keycodes[0]); + input_dev->keycodemax = mpr121->keycount; + + for (i = 0; i < pdata->keymap_size; i++) { + input_set_capability(input_dev, EV_KEY, pdata->keymap[i]); + mpr121->keycodes[i] = pdata->keymap[i]; + } + + error = mpr121_phys_init(pdata, mpr121, client); + if (error) { + dev_err(&client->dev, "Failed to init register\n"); + return error; + } + + error = devm_request_threaded_irq(&client->dev, client->irq, NULL, + mpr_touchkey_interrupt, + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + client->dev.driver->name, mpr121); + if (error) { + dev_err(&client->dev, "Failed to register interrupt\n"); + return error; + } + + error = input_register_device(input_dev); + if (error) + return error; + + i2c_set_clientdata(client, mpr121); + device_init_wakeup(&client->dev, pdata->wakeup); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int mpr_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + + if (device_may_wakeup(&client->dev)) + enable_irq_wake(client->irq); + + i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00); + + return 0; +} + +static int mpr_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client); + + if (device_may_wakeup(&client->dev)) + disable_irq_wake(client->irq); + + i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, + mpr121->keycount); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume); + +static const struct i2c_device_id mpr121_id[] = { + { "mpr121_touchkey", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, mpr121_id); + +static struct i2c_driver mpr_touchkey_driver = { + .driver = { + .name = "mpr121", + .owner = THIS_MODULE, + .pm = &mpr121_touchkey_pm_ops, + }, + .id_table = mpr121_id, + .probe = mpr_touchkey_probe, +}; + +module_i2c_driver(mpr_touchkey_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>"); +MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip"); |