--- /dev/null
+/*
+ * LM8333 keypad driver
+ * Copyright (C) 2012 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/irq.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/input/lm8333.h>
+
+#define LM8333_FIFO_READ 0x20
+#define LM8333_DEBOUNCE 0x22
+#define LM8333_READ_INT 0xD0
+#define LM8333_ACTIVE 0xE4
+#define LM8333_READ_ERROR 0xF0
+
+#define LM8333_KEYPAD_IRQ (1 << 0)
+#define LM8333_ERROR_IRQ (1 << 3)
+
+#define LM8333_ERROR_KEYOVR 0x04
+#define LM8333_ERROR_FIFOOVR 0x40
+
+#define LM8333_FIFO_TRANSFER_SIZE 16
+
+#define LM8333_ROW_SHIFT 4
+#define LM8333_NUM_ROWS 8
+
+
+struct lm8333 {
+ struct i2c_client *client;
+ struct input_dev *input;
+ unsigned short keycodes[LM8333_NUM_ROWS << LM8333_ROW_SHIFT];
+};
+
+/* The accessors try twice because the first access may be needed for wakeup */
+#define LM8333_READ_RETRIES 2
+
+int lm8333_read8(struct lm8333 *lm8333, u8 cmd)
+{
+ int retries = 0, ret;
+
+ do {
+ ret = i2c_smbus_read_byte_data(lm8333->client, cmd);
+ } while (ret < 0 && retries++ < LM8333_READ_RETRIES);
+
+ return ret;
+}
+
+int lm8333_write8(struct lm8333 *lm8333, u8 cmd, u8 val)
+{
+ int retries = 0, ret;
+
+ do {
+ ret = i2c_smbus_write_byte_data(lm8333->client, cmd, val);
+ } while (ret < 0 && retries++ < LM8333_READ_RETRIES);
+
+ return ret;
+}
+
+int lm8333_read_block(struct lm8333 *lm8333, u8 cmd, u8 len, u8 *buf)
+{
+ int retries = 0, ret;
+
+ do {
+ ret = i2c_smbus_read_i2c_block_data(lm8333->client,
+ cmd, len, buf);
+ } while (ret < 0 && retries++ < LM8333_READ_RETRIES);
+
+ return ret;
+}
+
+static void lm8333_key_handler(struct lm8333 *lm8333)
+{
+ struct input_dev *input = lm8333->input;
+ u8 keys[LM8333_FIFO_TRANSFER_SIZE];
+ u8 code, pressed;
+ int i, ret;
+
+ ret = lm8333_read_block(lm8333, LM8333_FIFO_READ,
+ LM8333_FIFO_TRANSFER_SIZE, keys);
+ if (ret != LM8333_FIFO_TRANSFER_SIZE) {
+ dev_err(&lm8333->client->dev,
+ "Error %d while reading FIFO\n", ret);
+ return;
+ }
+
+ for (i = 0; keys[i] && i < LM8333_FIFO_TRANSFER_SIZE; i++) {
+ pressed = keys[i] & 0x80;
+ code = keys[i] & 0x7f;
+
+ input_event(input, EV_MSC, MSC_SCAN, code);
+ input_report_key(input, lm8333->keycodes[code], pressed);
+ }
+
+ input_sync(input);
+}
+
+static irqreturn_t lm8333_irq_thread(int irq, void *data)
+{
+ struct lm8333 *lm8333 = data;
+ u8 status = lm8333_read8(lm8333, LM8333_READ_INT);
+
+ if (!status)
+ return IRQ_NONE;
+
+ if (status & LM8333_ERROR_IRQ) {
+ u8 err = lm8333_read8(lm8333, LM8333_READ_ERROR);
+
+ if (err & (LM8333_ERROR_KEYOVR | LM8333_ERROR_FIFOOVR)) {
+ u8 dummy[LM8333_FIFO_TRANSFER_SIZE];
+
+ lm8333_read_block(lm8333, LM8333_FIFO_READ,
+ LM8333_FIFO_TRANSFER_SIZE, dummy);
+ }
+ dev_err(&lm8333->client->dev, "Got error %02x\n", err);
+ }
+
+ if (status & LM8333_KEYPAD_IRQ)
+ lm8333_key_handler(lm8333);
+
+ return IRQ_HANDLED;
+}
+
+static int __devinit lm8333_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ const struct lm8333_platform_data *pdata = client->dev.platform_data;
+ struct lm8333 *lm8333;
+ struct input_dev *input;
+ int err, active_time;
+
+ if (!pdata)
+ return -EINVAL;
+
+ active_time = pdata->active_time ?: 500;
+ if (active_time / 3 <= pdata->debounce_time / 3) {
+ dev_err(&client->dev, "Active time not big enough!\n");
+ return -EINVAL;
+ }
+
+ lm8333 = kzalloc(sizeof(*lm8333), GFP_KERNEL);
+ input = input_allocate_device();
+ if (!lm8333 || !input) {
+ err = -ENOMEM;
+ goto free_mem;
+ }
+
+ lm8333->client = client;
+ lm8333->input = input;
+
+ input->name = client->name;
+ input->dev.parent = &client->dev;
+ input->id.bustype = BUS_I2C;
+
+ input->keycode = lm8333->keycodes;
+ input->keycodesize = sizeof(lm8333->keycodes[0]);
+ input->keycodemax = ARRAY_SIZE(lm8333->keycodes);
+ input->evbit[0] = BIT_MASK(EV_KEY);
+ input_set_capability(input, EV_MSC, MSC_SCAN);
+
+ matrix_keypad_build_keymap(pdata->matrix_data, LM8333_ROW_SHIFT,
+ input->keycode, input->keybit);
+
+ if (pdata->debounce_time) {
+ err = lm8333_write8(lm8333, LM8333_DEBOUNCE,
+ pdata->debounce_time / 3);
+ if (err)
+ dev_warn(&client->dev, "Unable to set debounce time\n");
+ }
+
+ if (pdata->active_time) {
+ err = lm8333_write8(lm8333, LM8333_ACTIVE,
+ pdata->active_time / 3);
+ if (err)
+ dev_warn(&client->dev, "Unable to set active time\n");
+ }
+
+ err = request_threaded_irq(client->irq, NULL, lm8333_irq_thread,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ "lm8333", lm8333);
+ if (err)
+ goto free_mem;
+
+ err = input_register_device(input);
+ if (err)
+ goto free_irq;
+
+ i2c_set_clientdata(client, lm8333);
+ return 0;
+
+ free_irq:
+ free_irq(client->irq, lm8333);
+ free_mem:
+ input_free_device(input);
+ kfree(lm8333);
+ return err;
+}
+
+static int __devexit lm8333_remove(struct i2c_client *client)
+{
+ struct lm8333 *lm8333 = i2c_get_clientdata(client);
+
+ free_irq(client->irq, lm8333);
+ input_unregister_device(lm8333->input);
+ kfree(lm8333);
+
+ return 0;
+}
+
+static const struct i2c_device_id lm8333_id[] = {
+ { "lm8333", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, lm8333_id);
+
+static struct i2c_driver lm8333_driver = {
+ .driver = {
+ .name = "lm8333",
+ .owner = THIS_MODULE,
+ },
+ .probe = lm8333_probe,
+ .remove = __devexit_p(lm8333_remove),
+ .id_table = lm8333_id,
+};
+module_i2c_driver(lm8333_driver);
+
+MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
+MODULE_DESCRIPTION("LM8333 keyboard driver");
+MODULE_LICENSE("GPL v2");
OSDN Git Service
