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-rw-r--r--firmware/drivers/mpr121.c350
1 files changed, 350 insertions, 0 deletions
diff --git a/firmware/drivers/mpr121.c b/firmware/drivers/mpr121.c
new file mode 100644
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+++ b/firmware/drivers/mpr121.c
@@ -0,0 +1,350 @@
+/***************************************************************************
+ * __________ __ ___.
+ * 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 "mpr121.h"
+#include "i2c.h"
+
+/* Touch status: EL{0,7} */
+#define REG_TOUCH_STATUS 0x00
+#define REG_TOUCH_STATUS__ELE(x) (1 << (x))
+/* Touch status: EL{8-11,prox}, overcurrent */
+#define REG_TOUCH_STATUS2 0x01
+#define REG_TOUCH_STATUS2__ELE(x) (1 << ((x) - 8))
+#define REG_TOUCH_STATUS2__ELEPROX (1 << 4)
+#define REG_TOUCH_STATUS2__OVCF (1 << 7)
+/* Out of range: EL{0,7} */
+#define REG_OOR_STATUS 0x02
+#define REG_OOR_STATUS__ELE(x) (1 << (x))
+/* Out of range: EL{8-11,prox}, autoconf err */
+#define REG_OOR_STATUS2 0x03
+#define REG_OOR_STATUS2__ELE(x) (1 << (x))
+#define REG_OOR_STATUS2__ELEPROX (1 << 4)
+#define REG_OOR_STATUS2__ACFF (1 << 6)
+#define REG_OOR_STATUS2__ARFF (1 << 7)
+/* Electrode X filtered data LSB */
+#define REG_EFDxLB(x) (0x04 + 0x02 * (x))
+/* Electrode X filtered data MSB */
+#define REG_EFDxHB(x) (0x05 + 0x02 * (x))
+/* Proximity electrode X filtered data LSB */
+#define REG_EFDPROXLB 0x1c
+/* Proximity electrode X filtered data MSB */
+#define REG_EFDPROXHB 0x1d
+/* Electrode baseline value */
+#define REG_ExBV(x) (0x1e + (x))
+/* Proximity electrode baseline value */
+#define REG_EPROXBV 0x2a
+/* Max Half Delta Rising */
+#define REG_MHDR 0x2b
+/* Noise Half Delta Rising */
+#define REG_NHDR 0x2c
+/* Noise Count Limit Rising */
+#define REG_NCLR 0x2d
+/* Filter Delay Limit Rising */
+#define REG_FDLR 0x2e
+/* Max Half Delta Falling */
+#define REG_MHDF 0x2f
+/* Noise Half Delta Falling */
+#define REG_NHDF 0x30
+/* Noise Count Limit Falling */
+#define REG_NCLF 0x31
+/* Filter Delay Limit Falling */
+#define REG_FDLF 0x32
+/* Noise Half Delta Touched */
+#define REG_NHDT 0x33
+/* Noise Count Limit Touched */
+#define REG_NCLT 0x34
+/* Filter Delay Limit Touched */
+#define REG_FDLT 0x35
+/* Proximity Max Half Delta Rising */
+#define REG_MHDPROXR 0x36
+/* Proximity Noise Half Delta Rising */
+#define REG_NHDPROXR 0x37
+/* Proximity Noise Count Limit Rising */
+#define REG_NCLPROXR 0x38
+/* Proximity Filter Delay Limit Rising */
+#define REG_FDLPROXR 0x39
+/* Proximity Max Half Delta Falling */
+#define REG_MHDPROXF 0x3a
+/* Proximity Noise Half Delta Falling */
+#define REG_NHDPROXF 0x3b
+/* Proximity Noise Count Limit Falling */
+#define REG_NCLPROXF 0x3c
+/* Proximity Filter Delay Limit Falling */
+#define REG_FDLPROXF 0x3d
+/* Proximity Noise Half Delta Touched */
+#define REG_NHDPROXT 0x3e
+/* Proximity Noise Count Limit Touched */
+#define REG_NCLPROXT 0x3f
+/* Proximity Filter Delay Limit Touched */
+#define REG_FDLPROXT 0x40
+/* Eletrode Touch Threshold */
+#define REG_ExTTH(x) (0x41 + 2 * (x))
+/* Eletrode Release Threshold */
+#define REG_ExRTH(x) (0x42 + 2 * (x))
+/* Proximity Eletrode Touch Threshold */
+#define REG_EPROXTTH 0x59
+/* Proximity Eletrode Release Threshold */
+#define REG_EPROXRTH 0x5a
+/* Debounce Control */
+#define REG_DEBOUNCE 0x5b
+#define REG_DEBOUNCE__DR(dr) ((dr) << 4)
+#define REG_DEBOUNCE__DT(dt) (dt)
+/* Analog Front End Configuration */
+#define REG_AFE 0x5c
+#define REG_AFE__CDC(cdc) (cdc)
+#define REG_AFE__FFI(ffi) ((ffi) << 6)
+/* Filter Configuration */
+#define REG_FILTER 0x5d
+#define REG_FILTER__ESI(esi) (esi)
+#define REG_FILTER__SFI(sfi) ((sfi) << 3)
+#define REG_FILTER__CDT(cdt) ((cdt) << 5)
+/* Electrode Configuration */
+#define REG_ELECTRODE 0x5e
+#define REG_ELECTRODE__ELE_EN(en) (en)
+#define REG_ELECTRODE__ELEPROX_EN(en) ((en) << 4)
+#define REG_ELECTRODE__CL(cl) ((cl) << 6)
+/* Electrode X Current */
+#define REG_CDCx(x) (0x5f + (x))
+/* Proximity Eletrode X Current */
+#define REG_CDCPROX 0x6b
+/* Electrode X Charge Time */
+#define REG_CDTx(x) (0x6c + (x) / 2)
+#define REG_CDTx__CDT0(x) (x)
+#define REG_CDTx__CDT1(x) ((x) << 4)
+/* Proximity Eletrode X Charge Time */
+#define REG_CDTPROX 0x72
+/* GPIO Control Register: CTL0{4-11} */
+#define REG_GPIO_CTL0 0x73
+#define REG_GPIO_CTL0__CTL0x(x) (1 << ((x) - 4))
+/* GPIO Control Register: CTL1{4-11} */
+#define REG_GPIO_CTL1 0x74
+#define REG_GPIO_CTL1__CTL1x(x) (1 << ((x) - 4))
+/* GPIO Data Register */
+#define REG_GPIO_DATA 0x75
+#define REG_GPIO_DATA__DATx(x) (1 << ((x) - 4))
+/* GPIO Direction Register */
+#define REG_GPIO_DIR 0x76
+#define REG_GPIO_DIR__DIRx(x) (1 << ((x) - 4))
+/* GPIO Enable Register */
+#define REG_GPIO_EN 0x77
+#define REG_GPIO_EN__ENx(x) (1 << ((x) - 4))
+/* GPIO Data Set Register */
+#define REG_GPIO_SET 0x78
+#define REG_GPIO_SET__SETx(x) (1 << ((x) - 4))
+/* GPIO Data Clear Register */
+#define REG_GPIO_CLR 0x79
+#define REG_GPIO_CLR__CLRx(x) (1 << ((x) - 4))
+/* GPIO Data Toggle Register */
+#define REG_GPIO_TOG 0x7a
+#define REG_GPIO_TOG__TOGx(x) (1 << ((x) - 4))
+/* Auto-Configuration Control 0 */
+#define REG_AUTO_CONF 0x7b
+#define REG_AUTO_CONF__ACE(ace) (ace)
+#define REG_AUTO_CONF__ARE(are) ((are) << 1)
+#define REG_AUTO_CONF__BVA(bva) ((bva) << 2)
+#define REG_AUTO_CONF__RETRY(retry) ((retry) << 4)
+#define REG_AUTO_CONF__FFI(ffi) ((ffi) << 6)
+/* Auto-Configuration Control 1 */
+#define REG_AUTO_CONF2 0x7c
+#define REG_AUTO_CONF2__ACFIE(acfie) (acfie)
+#define REG_AUTO_CONF2__ARFIE(arfie) ((arfie) << 1)
+#define REG_AUTO_CONF2__OORIE(oorie) ((oorie) << 2)
+#define REG_AUTO_CONF2__SCTS(scts) ((scts) << 7)
+/* Auto-Configuration Upper-Limit */
+#define REG_USL 0x7d
+/* Auto-Configuration Lower-Limit */
+#define REG_LSL 0x7e
+/* Auto-Configuration Target Level */
+#define REG_TL 0x7f
+/* Soft-Reset */
+#define REG_SOFTRESET 0x80
+#define REG_SOFTRESET__MAGIC 0x63
+/* PWM Control */
+#define REG_PWMx(x) (0x81 + ((x) - 4) / 2)
+#define REG_PWMx_IS_PWM0(x) (((x) % 2) == 0)
+#define REG_PWMx__PWM0(x) (x)
+#define REG_PWMx__PWM0_BM 0xf
+#define REG_PWMx__PWM1(x) ((x) << 4)
+#define REG_PWMx__PWM1_BM 0xf0
+
+static int i2c_addr;
+
+static inline int mpr121_write_reg(uint8_t reg, uint8_t data)
+{
+ return i2c_writemem(i2c_addr, reg, &data, 1);
+}
+
+static inline int mpr121_read_reg(uint8_t reg, uint8_t *data)
+{
+ return i2c_readmem(i2c_addr, reg, data, 1);
+}
+
+int mpr121_init(int dev_i2c_addr)
+{
+ i2c_addr = dev_i2c_addr;
+ return 0;
+}
+
+int mpr121_soft_reset(void)
+{
+ return mpr121_write_reg(REG_SOFTRESET, REG_SOFTRESET__MAGIC);
+}
+int mpr121_set_config(struct mpr121_config_t *conf)
+{
+ int ret;
+#define safe_write(reg, val) \
+ do { ret = mpr121_write_reg(reg, val); \
+ if(ret) return ret; } while(0)
+ /* stop mode */
+ safe_write(REG_ELECTRODE, 0);
+ /* write baseline values */
+ for(int i = 0; i < ELECTRODE_COUNT; i++)
+ safe_write(REG_ExBV(i), conf->ele[i].bv);
+ /* write eleprox bv */
+ safe_write(REG_EPROXBV, conf->eleprox.bv);
+ /* write global fields */
+ safe_write(REG_MHDR, conf->filters.ele.rising.mhd);
+ safe_write(REG_NHDR, conf->filters.ele.rising.nhd);
+ safe_write(REG_NCLR, conf->filters.ele.rising.ncl);
+ safe_write(REG_FDLR, conf->filters.ele.rising.fdl);
+ safe_write(REG_MHDF, conf->filters.ele.falling.mhd);
+ safe_write(REG_NHDF, conf->filters.ele.falling.nhd);
+ safe_write(REG_NCLF, conf->filters.ele.falling.ncl);
+ safe_write(REG_FDLF, conf->filters.ele.falling.fdl);
+ safe_write(REG_NHDT, conf->filters.ele.touched.nhd);
+ safe_write(REG_NCLT, conf->filters.ele.touched.ncl);
+ safe_write(REG_FDLT, conf->filters.ele.touched.fdl);
+ safe_write(REG_MHDPROXR, conf->filters.eleprox.rising.mhd);
+ safe_write(REG_NHDPROXR, conf->filters.eleprox.rising.nhd);
+ safe_write(REG_NCLPROXR, conf->filters.eleprox.rising.ncl);
+ safe_write(REG_FDLPROXR, conf->filters.eleprox.rising.fdl);
+ safe_write(REG_MHDPROXF, conf->filters.eleprox.falling.mhd);
+ safe_write(REG_NHDPROXF, conf->filters.eleprox.falling.nhd);
+ safe_write(REG_NCLPROXF, conf->filters.eleprox.falling.ncl);
+ safe_write(REG_FDLPROXF, conf->filters.eleprox.falling.fdl);
+ safe_write(REG_NHDPROXT, conf->filters.eleprox.touched.nhd);
+ safe_write(REG_NCLPROXT, conf->filters.eleprox.touched.ncl);
+ safe_write(REG_FDLPROXT, conf->filters.eleprox.touched.fdl);
+ /* touch & release thresholds */
+ for(int i = 0; i < ELECTRODE_COUNT; i++)
+ {
+ safe_write(REG_ExTTH(i), conf->ele[i].tth);
+ safe_write(REG_ExRTH(i), conf->ele[i].rth);
+ }
+ safe_write(REG_EPROXTTH, conf->eleprox.tth);
+ safe_write(REG_EPROXRTH, conf->eleprox.rth);
+ /* debounce */
+ safe_write(REG_DEBOUNCE, REG_DEBOUNCE__DR(conf->debounce.dr) |
+ REG_DEBOUNCE__DT(conf->debounce.dt));
+ /* analog-front end and filters */
+ safe_write(REG_AFE, REG_AFE__CDC(conf->global.cdc) |
+ REG_AFE__FFI(conf->global.ffi));
+ safe_write(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++)
+ safe_write(REG_CDCx(i), conf->ele[i].cdc);
+ safe_write(REG_CDCPROX, conf->eleprox.cdc);
+ for(int i = 0; i < ELECTRODE_COUNT; i += 2)
+ {
+ safe_write(REG_CDTx(i), REG_CDTx__CDT0(conf->ele[i].cdt) |
+ REG_CDTx__CDT1(conf->ele[i+1].cdt));
+ }
+ safe_write(REG_CDTPROX, conf->eleprox.cdt);
+ /* Auto-Configuration */
+ safe_write(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));
+ safe_write(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));
+ safe_write(REG_USL, conf->autoconf.usl);
+ safe_write(REG_LSL, conf->autoconf.lsl);
+ safe_write(REG_TL, conf->autoconf.tl);
+ /* electrode configuration */
+ safe_write(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);
+ safe_write(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);
+ safe_write(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);
+ safe_write(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);
+ safe_write(REG_GPIO_EN, ctl);
+
+ return 0;
+}
+
+int mpr121_set_gpio_output(int ele, int gpio_val)
+{
+ switch(gpio_val)
+ {
+ case ELE_GPIO_SET:
+ return mpr121_write_reg(REG_GPIO_SET, REG_GPIO_SET__SETx(ele));
+ case ELE_GPIO_CLR:
+ return mpr121_write_reg(REG_GPIO_CLR, REG_GPIO_CLR__CLRx(ele));
+ case ELE_GPIO_TOG:
+ return mpr121_write_reg(REG_GPIO_TOG, REG_GPIO_TOG__TOGx(ele));
+ default:
+ return -1;
+ }
+}
+
+int mpr121_set_gpio_pwm(int ele, int pwm)
+{
+ uint8_t reg_val;
+ int ret = mpr121_read_reg(REG_PWMx(ele), &reg_val);
+ if(ret) return ret;
+ 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);
+ return mpr121_write_reg(REG_PWMx(ele), reg_val);
+}
+
+int mpr121_get_touch_status(unsigned *status)
+{
+ uint8_t buf[2];
+ int ret = i2c_readmem(i2c_addr, REG_TOUCH_STATUS, buf, 2);
+ if(!ret && status)
+ *status = buf[0] | buf[1];
+ return ret;
+}