Add the MPR121 (touchbutton chip) driver

Change-Id: I9db97a698ef1c7f0b4f47e406faa1f6c0ec524db

1 files changed, 170 insertions, 0 deletions

diff --git a/firmware/export/mpr121.h b/firmware/export/mpr121.h
new file mode 100644
index 0000000..96b83ec
--- /dev/null
+++ b/firmware/export/mpr121.h
@@ -0,0 +1,170 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2012 Amaury Pouly
+ *
+ * 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, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+/** Driver for the Freescale MPR121 Capacitive Proximity Sensor */
+#include "system.h"
+
+#define ELECTRODE_COUNT 12
+#define ELE_GPIO_FIRST  4
+#define ELE_GPIO_LAST   11
+
+/* gpio config (encoding: [0]=en,[1]=dir,[2]=ctl[1],[3]=ctl[0]) */
+#define ELE_GPIO_DISABLE        0
+#define ELE_GPIO_INPUT          1
+#define ELE_GPIO_INPUT_PULLDOWN 9 /* input with pull-down */
+#define ELE_GPIO_INPUT_PULLUP   13 /* input with pull-up */
+#define ELE_GPIO_OUTPUT         3
+#define ELE_GPIO_OUTPUT_OPEN     11 /* open drain low-side */
+#define ELE_GPIO_OUTPUT_OPEN_LED 15 /* open drain high-side (led driver) */
+
+/* internal use */
+#define ELE_GPIO_EN(val)    ((val) & 1)
+#define ELE_GPIO_DIR(val)   (((val) >> 1) & 1)
+#define ELE_GPIO_CTL0(val)  (((val) >> 3) & 1)
+#define ELE_GPIO_CTL1(val)  (((val) >> 1) & 1)
+
+struct mpr121_electrode_config_t
+{
+    uint8_t bv; /* baseline value */
+    uint8_t tth; /* touch threshold */
+    uint8_t rth; /* release threshold */
+    uint8_t cdc; /* charge current (optional if auto-conf) */
+    uint8_t cdt; /* charge time (optional if auto-conf) */
+    int gpio; /* gpio config */
+};
+
+struct mpr121_baseline_filter_config_t
+{
+    uint8_t mhd; /* max half delta (except for touched) */
+    uint8_t nhd; /* noise half delta */
+    uint8_t ncl; /* noise count limit */
+    uint8_t fdl; /* filter delay count limit */
+};
+
+struct mpr121_baseline_filters_config_t
+{
+    struct mpr121_baseline_filter_config_t rising;
+    struct mpr121_baseline_filter_config_t falling;
+    struct mpr121_baseline_filter_config_t touched;
+};
+
+struct mpr121_debounce_config_t
+{
+    uint8_t dt; /* debounce count for touch */
+    uint8_t dr; /* debounce count for release */
+};
+
+/* first filter iterations */
+#define FFI_6_SAMPLES   0
+#define FFI_10_SAMPLES  1
+#define FFI_18_SAMPLES  2
+#define FFI_34_SAMPLES  3
+/* charge discharge current */
+#define CDC_DISABLE     0
+#define CDC_uA(ua)      (ua)
+/* charge discharge time */
+#define CDT_DISABLE     0
+#define CDT_log_us(lus) (lus) /* actual value = 2^{us-2} µs */
+/* second filter iterations */
+#define SFI_4_SAMPLES   0
+#define SFI_6_SAMPLES   1
+#define SFI_10_SAMPLES  2
+#define SFI_18_SAMPLES  3
+/* Eletrode sample interval */
+#define ESI_log_ms(lms) (lms) /* actual value = 2^{lms} ms */
+
+struct mpr121_global_config_t
+{
+    uint8_t ffi; /* first filter iterations */
+    uint8_t cdc; /* global charge discharge current */
+    uint8_t cdt; /* global charge discharge time */
+    uint8_t sfi; /* second first iterations */
+    uint8_t esi; /* electrode sample interval */
+};
+
+#define RETRY_NEVER     0
+#define RETRY_2_TIMES   1
+#define RETRY_4_TIMES   2
+#define RETRY_8_TIMES   3
+
+struct mpr121_auto_config_t
+{
+    bool en; /* auto-conf enable */
+    bool ren; /* auto-reconf enable */
+    uint8_t retry; /* retry count */
+    bool scts; /* skip charge time search */
+    uint8_t usl; /* upper-side limit */
+    uint8_t lsl; /* lower-side limit */
+    uint8_t tl; /* target level */
+    bool acfie; /* auto-conf fail interrupt en */
+    bool arfie; /* auto-reconf fail interrupt en */
+    bool oorie; /* out of range interrupt en */
+};
+
+/* electrode mode */
+#define ELE_DISABLE     0
+#define ELE_EN0_x(x)    ((x) + 1)
+/* eleprox mode */
+#define ELEPROX_DISABLE 0
+#define ELEPROX_EN0_1   1
+#define ELEPROX_EN0_3   2
+#define ELEPROX_EN0_11  3
+/* calibration lock */
+#define CL_SLOW_TRACK   0
+#define CL_DISABLE      1
+#define CL_TRACK        2
+#define CL_FAST_TRACK   3
+
+struct mpr121_config_t
+{
+    struct mpr121_electrode_config_t ele[ELECTRODE_COUNT];
+    struct mpr121_electrode_config_t eleprox;
+    struct
+    {
+        struct mpr121_baseline_filters_config_t ele;
+        struct mpr121_baseline_filters_config_t eleprox;
+    }filters;
+    struct mpr121_debounce_config_t debounce;
+    struct mpr121_global_config_t global;
+    struct mpr121_auto_config_t autoconf;
+    uint8_t ele_en; /* eletroce mode */
+    uint8_t eleprox_en; /* proximity mode */
+    uint8_t cal_lock; /* calibration lock */
+};
+
+/* gpio value */
+#define ELE_GPIO_CLR    0
+#define ELE_GPIO_SET    1
+#define ELE_GPIO_TOG    2
+/* pwm value */
+#define ELE_PWM_DISABLE 0
+#define ELE_PWM_DUTY(x) (x)
+#define ELE_PWM_MIN_DUTY    1
+#define ELE_PWM_MAX_DUTY    15
+
+int mpr121_init(int dev_i2c_addr);
+int mpr121_soft_reset(void);
+int mpr121_set_config(struct mpr121_config_t *conf);
+/* gpios are only implemented for electrode>=4 */
+int mpr121_set_gpio_output(int ele, int gpio_val);
+int mpr121_set_gpio_pwm(int ele, int pwm);
+/* get electrode status (bitmap) */
+int mpr121_get_touch_status(unsigned *status);