diff options
Diffstat (limited to 'nuttx/drivers/input/stmpe811_adc.c')
-rw-r--r-- | nuttx/drivers/input/stmpe811_adc.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/nuttx/drivers/input/stmpe811_adc.c b/nuttx/drivers/input/stmpe811_adc.c new file mode 100644 index 000000000..1ffe987e6 --- /dev/null +++ b/nuttx/drivers/input/stmpe811_adc.c @@ -0,0 +1,266 @@ +/**************************************************************************** + * drivers/input/stmpe811_adc.c + * + * Copyright (C) 2012 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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 <nuttx/config.h> + +#include <unistd.h> +#include <assert.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/arch.h> +#include <nuttx/input/stmpe811.h> + +#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 */ + |