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rockbox/firmware/target/arm/imx233/creative-zenxfi3/mpr121-zenxfi3.c
Amaury Pouly d42a4a4eb4 zenxfi3: rewrite mpr121 driver 
The new driver uses an asynchronous architecture for touch status reading.

Change-Id: Ic75a8b91bc47ee16c3af873afde178cd70186376
2016-06-01 23:09:27 +02:00

236 lines
9.4 KiB
C
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/***************************************************************************
* __________ __ ___.
* 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"
#include "kernel.h"
#include "usb.h"
#include "mpr121.h"
#include "mpr121-zenxfi3.h"
#include "i2c-imx233.h"
#include "pinctrl-imx233.h"
#define MPR121_I2C_ADDR 0xb4
/* NOTE on the architecture of the driver
*
* All non-time-critical operations (setup, gpio/pwm changes) are done with
* blocking i2c transfers to make the code simpler. Since reading the touch
* status is time critical, it is done asynchronously: when the IRQ pin is
* asserted, it will disable IRQ pin sensing and trigger an asynchronous i2c
* transfer to read touch status. When the transfer finishes, the driver will
* renable IRQ pin sensing. */
static unsigned touch_status = 0; /* touch bitmask as reported by mpr121 */
static struct imx233_i2c_xfer_t read_status_xfer; /* async transfer to read touch status */
static uint8_t read_status_sel_reg; /* buffer for async transfer operation */
static uint8_t read_status_buf[2]; /* buffer for async transfer operation */
static void mpr121_irq_cb(int bank, int pin, intptr_t user);
static void touch_status_i2c_cb(struct imx233_i2c_xfer_t *xfer, enum imx233_i2c_error_t status)
{
(void) xfer;
(void) status;
/* put status in the global variable */
touch_status = read_status_buf[0] | read_status_buf[1] << 8;
/* start sensing IRQ pin again */
imx233_pinctrl_setup_irq(0, 18, true, true, false, &mpr121_irq_cb, 0);
}
void mpr121_irq_cb(int bank, int pin, intptr_t user)
{
(void) bank;
(void) pin;
(void) user;
/* NOTE the callback will not be fired until interrupt is enabled back.
*
* now setup an asynchronous i2c transfer to read touch status register,
* this is a readmem operation with a first stage to select register
* and a second stage to read status (2 bytes) */
read_status_sel_reg = REG_TOUCH_STATUS;
read_status_xfer.next = NULL;
read_status_xfer.fast_mode = true;
read_status_xfer.dev_addr = MPR121_I2C_ADDR;
read_status_xfer.mode = I2C_READ;
read_status_xfer.count[0] = 1; /* set touch status register address */
read_status_xfer.data[0] = &read_status_sel_reg;
read_status_xfer.count[1] = 2;
read_status_xfer.data[1] = &read_status_buf;
read_status_xfer.tmo_ms = 1000;
read_status_xfer.callback = &touch_status_i2c_cb;
imx233_i2c_transfer(&read_status_xfer);
}
static inline int mpr121_write_reg(uint8_t reg, uint8_t data)
{
return i2c_writemem(MPR121_I2C_ADDR, reg, &data, 1);
}
static inline int mpr121_read_reg(uint8_t reg, uint8_t *data)
{
return i2c_readmem(MPR121_I2C_ADDR, reg, data, 1);
}
void mpr121_init(void)
{
/* soft reset */
mpr121_write_reg(REG_SOFTRESET, REG_SOFTRESET__MAGIC);
/* enable interrupt */
imx233_pinctrl_acquire(0, 18, "mpr121_int");
imx233_pinctrl_set_function(0, 18, PINCTRL_FUNCTION_GPIO);
imx233_pinctrl_enable_gpio(0, 18, false);
imx233_pinctrl_setup_irq(0, 18, true, true, false, &mpr121_irq_cb, 0);
}
void mpr121_set_config(struct mpr121_config_t *conf)
{
/* stop mode */
mpr121_write_reg(REG_ELECTRODE, 0);
/* write baseline values */
for(int i = 0; i < ELECTRODE_COUNT; i++)
mpr121_write_reg(REG_ExBV(i), conf->ele[i].bv);
/* write eleprox bv */
mpr121_write_reg(REG_EPROXBV, conf->eleprox.bv);
/* write global fields */
mpr121_write_reg(REG_MHDR, conf->filters.ele.rising.mhd);
mpr121_write_reg(REG_NHDR, conf->filters.ele.rising.nhd);
mpr121_write_reg(REG_NCLR, conf->filters.ele.rising.ncl);
mpr121_write_reg(REG_FDLR, conf->filters.ele.rising.fdl);
mpr121_write_reg(REG_MHDF, conf->filters.ele.falling.mhd);
mpr121_write_reg(REG_NHDF, conf->filters.ele.falling.nhd);
mpr121_write_reg(REG_NCLF, conf->filters.ele.falling.ncl);
mpr121_write_reg(REG_FDLF, conf->filters.ele.falling.fdl);
mpr121_write_reg(REG_NHDT, conf->filters.ele.touched.nhd);
mpr121_write_reg(REG_NCLT, conf->filters.ele.touched.ncl);
mpr121_write_reg(REG_FDLT, conf->filters.ele.touched.fdl);
mpr121_write_reg(REG_MHDPROXR, conf->filters.eleprox.rising.mhd);
mpr121_write_reg(REG_NHDPROXR, conf->filters.eleprox.rising.nhd);
mpr121_write_reg(REG_NCLPROXR, conf->filters.eleprox.rising.ncl);
mpr121_write_reg(REG_FDLPROXR, conf->filters.eleprox.rising.fdl);
mpr121_write_reg(REG_MHDPROXF, conf->filters.eleprox.falling.mhd);
mpr121_write_reg(REG_NHDPROXF, conf->filters.eleprox.falling.nhd);
mpr121_write_reg(REG_NCLPROXF, conf->filters.eleprox.falling.ncl);
mpr121_write_reg(REG_FDLPROXF, conf->filters.eleprox.falling.fdl);
mpr121_write_reg(REG_NHDPROXT, conf->filters.eleprox.touched.nhd);
mpr121_write_reg(REG_NCLPROXT, conf->filters.eleprox.touched.ncl);
mpr121_write_reg(REG_FDLPROXT, conf->filters.eleprox.touched.fdl);
/* touch & release thresholds */
for(int i = 0; i < ELECTRODE_COUNT; i++)
{
mpr121_write_reg(REG_ExTTH(i), conf->ele[i].tth);
mpr121_write_reg(REG_ExRTH(i), conf->ele[i].rth);
}
mpr121_write_reg(REG_EPROXTTH, conf->eleprox.tth);
mpr121_write_reg(REG_EPROXRTH, conf->eleprox.rth);
/* debounce */
mpr121_write_reg(REG_DEBOUNCE, REG_DEBOUNCE__DR(conf->debounce.dr) |
REG_DEBOUNCE__DT(conf->debounce.dt));
/* analog-front end and filters */
mpr121_write_reg(REG_AFE, REG_AFE__CDC(conf->global.cdc) |
REG_AFE__FFI(conf->global.ffi));
mpr121_write_reg(REG_FILTER, REG_FILTER__CDT(conf->global.cdt) |
REG_FILTER__ESI(conf->global.esi) | REG_FILTER__SFI(conf->global.sfi));
/* electrode charge */
for(int i = 0; i < ELECTRODE_COUNT; i++)
mpr121_write_reg(REG_CDCx(i), conf->ele[i].cdc);
mpr121_write_reg(REG_CDCPROX, conf->eleprox.cdc);
for(int i = 0; i < ELECTRODE_COUNT; i += 2)
{
mpr121_write_reg(REG_CDTx(i), REG_CDTx__CDT0(conf->ele[i].cdt) |
REG_CDTx__CDT1(conf->ele[i+1].cdt));
}
mpr121_write_reg(REG_CDTPROX, conf->eleprox.cdt);
/* Auto-Configuration */
mpr121_write_reg(REG_AUTO_CONF, REG_AUTO_CONF__ACE(conf->autoconf.en) |
REG_AUTO_CONF__ARE(conf->autoconf.ren) |
REG_AUTO_CONF__BVA(conf->cal_lock) |
REG_AUTO_CONF__RETRY(conf->autoconf.retry) |
REG_AUTO_CONF__FFI(conf->global.ffi));
mpr121_write_reg(REG_AUTO_CONF2, REG_AUTO_CONF2__ACFIE(conf->autoconf.acfie) |
REG_AUTO_CONF2__ARFIE(conf->autoconf.arfie) |
REG_AUTO_CONF2__OORIE(conf->autoconf.oorie) |
REG_AUTO_CONF2__SCTS(conf->autoconf.scts));
mpr121_write_reg(REG_USL, conf->autoconf.usl);
mpr121_write_reg(REG_LSL, conf->autoconf.lsl);
mpr121_write_reg(REG_TL, conf->autoconf.tl);
/* electrode configuration */
mpr121_write_reg(REG_ELECTRODE, REG_ELECTRODE__ELE_EN(conf->ele_en) |
REG_ELECTRODE__ELEPROX_EN(conf->eleprox_en) |
REG_ELECTRODE__CL(conf->cal_lock));
/* gpio config */
uint8_t ctl = 0;
for(int i = ELE_GPIO_FIRST; i <= ELE_GPIO_LAST; i++)
if(ELE_GPIO_CTL0(conf->ele[i].gpio))
ctl |= REG_GPIO_CTL0__CTL0x(i);
mpr121_write_reg(REG_GPIO_CTL0, ctl);
ctl = 0;
for(int i = ELE_GPIO_FIRST; i <= ELE_GPIO_LAST; i++)
if(ELE_GPIO_CTL1(conf->ele[i].gpio))
ctl |= REG_GPIO_CTL1__CTL1x(i);
mpr121_write_reg(REG_GPIO_CTL1, ctl);
ctl = 0;
for(int i = ELE_GPIO_FIRST; i <= ELE_GPIO_LAST; i++)
if(ELE_GPIO_DIR(conf->ele[i].gpio))
ctl |= REG_GPIO_DIR__DIRx(i);
mpr121_write_reg(REG_GPIO_DIR, ctl);
ctl = 0;
for(int i = ELE_GPIO_FIRST; i <= ELE_GPIO_LAST; i++)
if(ELE_GPIO_EN(conf->ele[i].gpio))
ctl |= REG_GPIO_EN__ENx(i);
mpr121_write_reg(REG_GPIO_EN, ctl);
}
void mpr121_set_gpio_output(int ele, int gpio_val)
{
switch(gpio_val)
{
case ELE_GPIO_SET:
mpr121_write_reg(REG_GPIO_SET, REG_GPIO_SET__SETx(ele));
break;
case ELE_GPIO_CLR:
mpr121_write_reg(REG_GPIO_CLR, REG_GPIO_CLR__CLRx(ele));
break;
case ELE_GPIO_TOG:
mpr121_write_reg(REG_GPIO_TOG, REG_GPIO_TOG__TOGx(ele));
break;
default:
break;
}
}
void mpr121_set_gpio_pwm(int ele, int pwm)
{
uint8_t reg_val;
mpr121_read_reg(REG_PWMx(ele), &reg_val);
if(REG_PWMx_IS_PWM0(ele))
reg_val = (reg_val & ~REG_PWMx__PWM0_BM) | REG_PWMx__PWM0(pwm);
else
reg_val = (reg_val & ~REG_PWMx__PWM1_BM) | REG_PWMx__PWM1(pwm);
mpr121_write_reg(REG_PWMx(ele), reg_val);
}
unsigned mpr121_get_touch_status(void)
{
return touch_status;
}
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