--- /dev/null
+/*
+ * 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");
Code Review / kvmfornfv.git / blobdiff