Input: add support for LM8333 keypads
authorWolfram Sang <w.sang@pengutronix.de>
Tue, 3 Apr 2012 20:39:44 +0000 (13:39 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Wed, 4 Apr 2012 16:25:39 +0000 (09:25 -0700)
This driver adds support for the keypad part of the LM8333 and is
prepared for possible GPIO/PWM drivers. Note that this is not a MFD
because you cannot disable the keypad functionality which, thus,
has to be handled by the core anyhow.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
drivers/input/keyboard/Kconfig
drivers/input/keyboard/Makefile
drivers/input/keyboard/lm8333.c [new file with mode: 0644]
include/linux/input/lm8333.h [new file with mode: 0644]

index f354813a13e8608868040355e3a1f4f19cf2b139..7eaf93fe51280a48b9a6e45b0a5644f794ff3db6 100644 (file)
@@ -309,6 +309,16 @@ config KEYBOARD_LM8323
          To compile this driver as a module, choose M here: the
          module will be called lm8323.
 
+config KEYBOARD_LM8333
+       tristate "LM8333 keypad chip"
+       depends on I2C
+       help
+         If you say yes here you get support for the National Semiconductor
+         LM8333 keypad controller.
+
+         To compile this driver as a module, choose M here: the
+         module will be called lm8333.
+
 config KEYBOARD_LOCOMO
        tristate "LoCoMo Keyboard Support"
        depends on SHARP_LOCOMO
index df7061f129184f4c5dfb6265229529fe1387dcf7..b03b02456a828d03570bb0b8d950f0ebbb2b7589 100644 (file)
@@ -24,6 +24,7 @@ obj-$(CONFIG_KEYBOARD_HP6XX)          += jornada680_kbd.o
 obj-$(CONFIG_KEYBOARD_HP7XX)           += jornada720_kbd.o
 obj-$(CONFIG_KEYBOARD_LKKBD)           += lkkbd.o
 obj-$(CONFIG_KEYBOARD_LM8323)          += lm8323.o
+obj-$(CONFIG_KEYBOARD_LM8333)          += lm8333.o
 obj-$(CONFIG_KEYBOARD_LOCOMO)          += locomokbd.o
 obj-$(CONFIG_KEYBOARD_MAPLE)           += maple_keyb.o
 obj-$(CONFIG_KEYBOARD_MATRIX)          += matrix_keypad.o
diff --git a/drivers/input/keyboard/lm8333.c b/drivers/input/keyboard/lm8333.c
new file mode 100644 (file)
index 0000000..9a8c4a6
--- /dev/null
@@ -0,0 +1,236 @@
+/*
+ * 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");
diff --git a/include/linux/input/lm8333.h b/include/linux/input/lm8333.h
new file mode 100644 (file)
index 0000000..79f918c
--- /dev/null
@@ -0,0 +1,24 @@
+/*
+ * public include for LM8333 keypad driver - same license as driver
+ * Copyright (C) 2012 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
+ */
+
+#ifndef _LM8333_H
+#define _LM8333_H
+
+struct lm8333;
+
+struct lm8333_platform_data {
+       /* Keymap data */
+       const struct matrix_keymap_data *matrix_data;
+       /* Active timeout before enter HALT mode in microseconds */
+       unsigned active_time;
+       /* Debounce interval in microseconds */
+       unsigned debounce_time;
+};
+
+extern int lm8333_read8(struct lm8333 *lm8333, u8 cmd);
+extern int lm8333_write8(struct lm8333 *lm8333, u8 cmd, u8 val);
+extern int lm8333_read_block(struct lm8333 *lm8333, u8 cmd, u8 len, u8 *buf);
+
+#endif /* _LM8333_H */