/**************************************************************************** * drivers/input/stmpe811_adc.c * * Copyright (C) 2012 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * References: * "STMPE811 S-Touch® advanced resistive touchscreen controller with 8-bit * GPIO expander," Doc ID 14489 Rev 6, CD00186725, STMicroelectronics" * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include "stmpe811.h" #if defined(CONFIG_INPUT) && defined(CONFIG_INPUT_STMPE811) && !defined(CONFIG_STMPE811_ADC_DISABLE) /**************************************************************************** * Private Types ****************************************************************************/ /**************************************************************************** * Private Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: stmpe811_adcinitialize * * Description: * Configure for ADC mode operation. Set overall ADC ADC timing that * applies to all pins. * * Input Parameters: * handle - The handle previously returned by stmpe811_instantiate * * Returned Value: * Zero is returned on success. Otherwise, a negated errno value is * returned to indicate the nature of the failure. * ****************************************************************************/ int stmpe811_adcinitialize(STMPE811_HANDLE handle) { FAR struct stmpe811_dev_s *priv = (FAR struct stmpe811_dev_s *)handle; uint8_t regval; int ret; DEBUGASSERT(handle); /* Get exclusive access to the device structure */ ret = sem_wait(&priv->exclsem); if (ret < 0) { int errval = errno; idbg("sem_wait failed: %d\n", errval); return -errval; } /* Enable Clocking for ADC */ regval = stmpe811_getreg8(priv, STMPE811_SYS_CTRL2); regval &= ~SYS_CTRL2_ADC_OFF; stmpe811_putreg8(priv, STMPE811_SYS_CTRL2, regval); /* Select Sample Time, bit number and ADC Reference */ stmpe811_putreg8(priv, STMPE811_ADC_CTRL1, priv->config->ctrl1); /* Wait for 20 ms */ up_mdelay(20); /* Select the ADC clock speed */ stmpe811_putreg8(priv, STMPE811_ADC_CTRL2, priv->config->ctrl2); /* Mark ADC initialized */ priv->flags |= STMPE811_FLAGS_ADC_INITIALIZED; sem_post(&priv->exclsem); return OK; } /**************************************************************************** * Name: stmpe811_adcconfig * * Description: * Configure a pin for ADC input. * * Input Parameters: * handle - The handle previously returned by stmpe811_instantiate * pin - The ADC pin number * * Returned Value: * Zero is returned on success. Otherwise, a negated errno value is * returned to indicate the nature of the failure. * ****************************************************************************/ int stmpe811_adcconfig(STMPE811_HANDLE handle, int pin) { FAR struct stmpe811_dev_s *priv = (FAR struct stmpe811_dev_s *)handle; uint8_t pinmask = GPIO_PIN(pin); uint8_t regval; int ret; DEBUGASSERT(handle && (unsigned)pin < STMPE811_ADC_NPINS); /* Get exclusive access to the device structure */ ret = sem_wait(&priv->exclsem); if (ret < 0) { int errval = errno; idbg("sem_wait failed: %d\n", errval); return -errval; } /* Make sure that the pin is not already in use */ if ((priv->inuse & pinmask) != 0) { idbg("PIN%d is already in-use\n", pin); sem_post(&priv->exclsem); return -EBUSY; } /* Clear the alternate function bit for the pin, making it an ADC input * (or perhaps an an external reference, depending on the state of the * ADC_CTRL1_REF_SEL bit). */ regval = stmpe811_getreg8(priv, STMPE811_GPIO_AF); regval &= ~pinmask; stmpe811_putreg8(priv, STMPE811_GPIO_AF, regval); /* Mark the pin as 'in use' */ priv->inuse |= pinmask; sem_post(&priv->exclsem); return OK; } /**************************************************************************** * Name: stmpe811_adcread * * Description: * Read the converted analog input value from the select pin. * * Input Parameters: * handle - The handle previously returned by stmpe811_instantiate * pin - The ADC pin number * * Returned Value: * The converted value (there is no error reporting mechanism). * ****************************************************************************/ uint16_t stmpe811_adcread(STMPE811_HANDLE handle, int pin) { FAR struct stmpe811_dev_s *priv = (FAR struct stmpe811_dev_s *)handle; uint8_t pinmask = GPIO_PIN(pin); uint8_t regval; int i; int ret; DEBUGASSERT(handle && (unsigned)pin < 8); /* Get exclusive access to the device structure */ ret = sem_wait(&priv->exclsem); if (ret < 0) { int errval = errno; idbg("sem_wait failed: %d\n", errval); return -errval; } /* Request AD conversion by setting the bit corresponding the pin in the * ADC CAPT register. */ stmpe811_putreg8(priv, STMPE811_ADC_CAPT, pinmask); /* Wait for the conversion to complete. The ADC CAPT register reads '1' * if conversion is completed. Reads '0' if conversion is in progress. * Try three times before giving up. */ for (i = 0; i < 3; i++) { /* The worst case ADC conversion time is (nominally) 56.4 uS. The * following usleep() looks nice but in reality, the usleep() * does not have that kind of precision (it will probably end up * waiting 10 MS). */ usleep(57); /* Check if the conversion is complete */ regval = stmpe811_getreg8(priv, STMPE811_ADC_CAPT); if ((regval & pinmask) != 0) { break; } } /* At the completion of the conversion, return whatever we read from * from the channel register associated with the pin. */ return stmpe811_getreg16(priv, STMPE811_ADC_DATACH(pin)); } #endif /* CONFIG_INPUT && CONFIG_INPUT_STMPE811 && !CONFIG_STMPE811_ADC_DISABLE */