237 lines
9.4 KiB
C
237 lines
9.4 KiB
C
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/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2012 Amaury Pouly
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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/** Driver for the Freescale MPR121 Capacitive Proximity Sensor */
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#include "system.h"
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#include "kernel.h"
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#include "usb.h"
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#include "mpr121.h"
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#include "mpr121-zenxfi3.h"
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#include "i2c-imx233.h"
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#include "pinctrl-imx233.h"
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#define MPR121_I2C_ADDR 0xb4
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/* NOTE on the architecture of the driver
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*
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* All non-time-critical operations (setup, gpio/pwm changes) are done with
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* blocking i2c transfers to make the code simpler. Since reading the touch
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* status is time critical, it is done asynchronously: when the IRQ pin is
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* asserted, it will disable IRQ pin sensing and trigger an asynchronous i2c
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* transfer to read touch status. When the transfer finishes, the driver will
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* renable IRQ pin sensing. */
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static unsigned touch_status = 0; /* touch bitmask as reported by mpr121 */
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static struct imx233_i2c_xfer_t read_status_xfer; /* async transfer to read touch status */
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static uint8_t read_status_sel_reg; /* buffer for async transfer operation */
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static uint8_t read_status_buf[2]; /* buffer for async transfer operation */
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static void mpr121_irq_cb(int bank, int pin, intptr_t user);
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static void touch_status_i2c_cb(struct imx233_i2c_xfer_t *xfer, enum imx233_i2c_error_t status)
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{
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(void) xfer;
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(void) status;
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/* put status in the global variable */
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touch_status = read_status_buf[0] | read_status_buf[1] << 8;
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/* start sensing IRQ pin again */
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imx233_pinctrl_setup_irq(0, 18, true, true, false, &mpr121_irq_cb, 0);
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}
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void mpr121_irq_cb(int bank, int pin, intptr_t user)
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{
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(void) bank;
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(void) pin;
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(void) user;
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/* NOTE the callback will not be fired until interrupt is enabled back.
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*
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* now setup an asynchronous i2c transfer to read touch status register,
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* this is a readmem operation with a first stage to select register
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* and a second stage to read status (2 bytes) */
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read_status_sel_reg = REG_TOUCH_STATUS;
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read_status_xfer.next = NULL;
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read_status_xfer.fast_mode = true;
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read_status_xfer.dev_addr = MPR121_I2C_ADDR;
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read_status_xfer.mode = I2C_READ;
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read_status_xfer.count[0] = 1; /* set touch status register address */
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read_status_xfer.data[0] = &read_status_sel_reg;
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read_status_xfer.count[1] = 2;
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read_status_xfer.data[1] = &read_status_buf;
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read_status_xfer.tmo_ms = 1000;
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read_status_xfer.callback = &touch_status_i2c_cb;
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imx233_i2c_transfer(&read_status_xfer);
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}
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static inline int mpr121_write_reg(uint8_t reg, uint8_t data)
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{
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return i2c_writemem(MPR121_I2C_ADDR, reg, &data, 1);
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}
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static inline int mpr121_read_reg(uint8_t reg, uint8_t *data)
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{
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return i2c_readmem(MPR121_I2C_ADDR, reg, data, 1);
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}
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void mpr121_init(void)
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{
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/* soft reset */
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mpr121_write_reg(REG_SOFTRESET, REG_SOFTRESET__MAGIC);
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/* enable interrupt */
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imx233_pinctrl_acquire(0, 18, "mpr121_int");
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imx233_pinctrl_set_function(0, 18, PINCTRL_FUNCTION_GPIO);
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imx233_pinctrl_enable_gpio(0, 18, false);
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imx233_pinctrl_setup_irq(0, 18, true, true, false, &mpr121_irq_cb, 0);
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}
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void mpr121_set_config(struct mpr121_config_t *conf)
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{
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/* stop mode */
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mpr121_write_reg(REG_ELECTRODE, 0);
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/* write baseline values */
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for(int i = 0; i < ELECTRODE_COUNT; i++)
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mpr121_write_reg(REG_ExBV(i), conf->ele[i].bv);
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/* write eleprox bv */
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mpr121_write_reg(REG_EPROXBV, conf->eleprox.bv);
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/* write global fields */
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mpr121_write_reg(REG_MHDR, conf->filters.ele.rising.mhd);
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mpr121_write_reg(REG_NHDR, conf->filters.ele.rising.nhd);
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mpr121_write_reg(REG_NCLR, conf->filters.ele.rising.ncl);
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mpr121_write_reg(REG_FDLR, conf->filters.ele.rising.fdl);
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mpr121_write_reg(REG_MHDF, conf->filters.ele.falling.mhd);
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mpr121_write_reg(REG_NHDF, conf->filters.ele.falling.nhd);
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mpr121_write_reg(REG_NCLF, conf->filters.ele.falling.ncl);
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mpr121_write_reg(REG_FDLF, conf->filters.ele.falling.fdl);
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mpr121_write_reg(REG_NHDT, conf->filters.ele.touched.nhd);
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mpr121_write_reg(REG_NCLT, conf->filters.ele.touched.ncl);
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mpr121_write_reg(REG_FDLT, conf->filters.ele.touched.fdl);
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mpr121_write_reg(REG_MHDPROXR, conf->filters.eleprox.rising.mhd);
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mpr121_write_reg(REG_NHDPROXR, conf->filters.eleprox.rising.nhd);
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mpr121_write_reg(REG_NCLPROXR, conf->filters.eleprox.rising.ncl);
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mpr121_write_reg(REG_FDLPROXR, conf->filters.eleprox.rising.fdl);
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mpr121_write_reg(REG_MHDPROXF, conf->filters.eleprox.falling.mhd);
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mpr121_write_reg(REG_NHDPROXF, conf->filters.eleprox.falling.nhd);
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mpr121_write_reg(REG_NCLPROXF, conf->filters.eleprox.falling.ncl);
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mpr121_write_reg(REG_FDLPROXF, conf->filters.eleprox.falling.fdl);
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mpr121_write_reg(REG_NHDPROXT, conf->filters.eleprox.touched.nhd);
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mpr121_write_reg(REG_NCLPROXT, conf->filters.eleprox.touched.ncl);
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mpr121_write_reg(REG_FDLPROXT, conf->filters.eleprox.touched.fdl);
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/* touch & release thresholds */
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for(int i = 0; i < ELECTRODE_COUNT; i++)
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{
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mpr121_write_reg(REG_ExTTH(i), conf->ele[i].tth);
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mpr121_write_reg(REG_ExRTH(i), conf->ele[i].rth);
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}
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mpr121_write_reg(REG_EPROXTTH, conf->eleprox.tth);
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mpr121_write_reg(REG_EPROXRTH, conf->eleprox.rth);
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/* debounce */
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mpr121_write_reg(REG_DEBOUNCE, REG_DEBOUNCE__DR(conf->debounce.dr) |
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REG_DEBOUNCE__DT(conf->debounce.dt));
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/* analog-front end and filters */
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mpr121_write_reg(REG_AFE, REG_AFE__CDC(conf->global.cdc) |
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REG_AFE__FFI(conf->global.ffi));
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mpr121_write_reg(REG_FILTER, REG_FILTER__CDT(conf->global.cdt) |
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REG_FILTER__ESI(conf->global.esi) | REG_FILTER__SFI(conf->global.sfi));
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/* electrode charge */
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for(int i = 0; i < ELECTRODE_COUNT; i++)
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mpr121_write_reg(REG_CDCx(i), conf->ele[i].cdc);
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mpr121_write_reg(REG_CDCPROX, conf->eleprox.cdc);
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for(int i = 0; i < ELECTRODE_COUNT; i += 2)
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{
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mpr121_write_reg(REG_CDTx(i), REG_CDTx__CDT0(conf->ele[i].cdt) |
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REG_CDTx__CDT1(conf->ele[i+1].cdt));
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}
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mpr121_write_reg(REG_CDTPROX, conf->eleprox.cdt);
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/* Auto-Configuration */
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mpr121_write_reg(REG_AUTO_CONF, REG_AUTO_CONF__ACE(conf->autoconf.en) |
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REG_AUTO_CONF__ARE(conf->autoconf.ren) |
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REG_AUTO_CONF__BVA(conf->cal_lock) |
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REG_AUTO_CONF__RETRY(conf->autoconf.retry) |
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REG_AUTO_CONF__FFI(conf->global.ffi));
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mpr121_write_reg(REG_AUTO_CONF2, REG_AUTO_CONF2__ACFIE(conf->autoconf.acfie) |
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REG_AUTO_CONF2__ARFIE(conf->autoconf.arfie) |
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REG_AUTO_CONF2__OORIE(conf->autoconf.oorie) |
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REG_AUTO_CONF2__SCTS(conf->autoconf.scts));
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mpr121_write_reg(REG_USL, conf->autoconf.usl);
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mpr121_write_reg(REG_LSL, conf->autoconf.lsl);
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mpr121_write_reg(REG_TL, conf->autoconf.tl);
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/* electrode configuration */
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mpr121_write_reg(REG_ELECTRODE, REG_ELECTRODE__ELE_EN(conf->ele_en) |
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REG_ELECTRODE__ELEPROX_EN(conf->eleprox_en) |
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REG_ELECTRODE__CL(conf->cal_lock));
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/* gpio config */
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uint8_t ctl = 0;
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for(int i = ELE_GPIO_FIRST; i <= ELE_GPIO_LAST; i++)
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if(ELE_GPIO_CTL0(conf->ele[i].gpio))
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ctl |= REG_GPIO_CTL0__CTL0x(i);
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mpr121_write_reg(REG_GPIO_CTL0, ctl);
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ctl = 0;
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for(int i = ELE_GPIO_FIRST; i <= ELE_GPIO_LAST; i++)
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if(ELE_GPIO_CTL1(conf->ele[i].gpio))
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ctl |= REG_GPIO_CTL1__CTL1x(i);
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mpr121_write_reg(REG_GPIO_CTL1, ctl);
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ctl = 0;
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for(int i = ELE_GPIO_FIRST; i <= ELE_GPIO_LAST; i++)
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if(ELE_GPIO_DIR(conf->ele[i].gpio))
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ctl |= REG_GPIO_DIR__DIRx(i);
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mpr121_write_reg(REG_GPIO_DIR, ctl);
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ctl = 0;
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for(int i = ELE_GPIO_FIRST; i <= ELE_GPIO_LAST; i++)
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if(ELE_GPIO_EN(conf->ele[i].gpio))
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ctl |= REG_GPIO_EN__ENx(i);
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mpr121_write_reg(REG_GPIO_EN, ctl);
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}
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void mpr121_set_gpio_output(int ele, int gpio_val)
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{
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switch(gpio_val)
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{
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case ELE_GPIO_SET:
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mpr121_write_reg(REG_GPIO_SET, REG_GPIO_SET__SETx(ele));
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break;
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case ELE_GPIO_CLR:
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mpr121_write_reg(REG_GPIO_CLR, REG_GPIO_CLR__CLRx(ele));
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break;
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case ELE_GPIO_TOG:
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mpr121_write_reg(REG_GPIO_TOG, REG_GPIO_TOG__TOGx(ele));
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break;
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default:
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break;
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}
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}
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void mpr121_set_gpio_pwm(int ele, int pwm)
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{
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uint8_t reg_val;
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mpr121_read_reg(REG_PWMx(ele), ®_val);
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if(REG_PWMx_IS_PWM0(ele))
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reg_val = (reg_val & ~REG_PWMx__PWM0_BM) | REG_PWMx__PWM0(pwm);
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else
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reg_val = (reg_val & ~REG_PWMx__PWM1_BM) | REG_PWMx__PWM1(pwm);
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mpr121_write_reg(REG_PWMx(ele), reg_val);
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}
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unsigned mpr121_get_touch_status(void)
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{
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return touch_status;
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}
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