seesaw/bsp/pinmux.cpp
2018-04-19 16:45:16 -04:00

173 lines
6.2 KiB
C++

/**
* \file
*
* \brief SAM Pin Multiplexer Driver
*
* Copyright (C) 2012-2015 Atmel Corporation. All rights reserved.
*
* \asf_license_start
*
* \page License
*
* 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. The name of Atmel may not be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 4. This software may only be redistributed and used in connection with an
* Atmel microcontroller product.
*
* THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
* EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL 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.
*
* \asf_license_stop
*
*/
/*
* Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
*/
// THIS IS A PARED-DOWN VERSION OF PINMUX.H FROM ATMEL ASFCORE 3.
// Please keep original copyright and license intact!
#include "pinmux.h"
/**
* \internal
* Writes out a given configuration of a Port pin configuration to the
* hardware module.
*
* \note If the pin direction is set as an output, the pull-up/pull-down input
* configuration setting is ignored.
*
* \param[in] port Base of the PORT module to configure
* \param[in] pin_mask Mask of the port pin to configure
* \param[in] config Configuration settings for the pin
*/
static void _system_pinmux_config(
PortGroup *const port,
const uint32_t pin_mask,
const struct system_pinmux_config *const config)
{
// Assert(port);
// Assert(config);
/* Track the configuration bits into a temporary variable before writing */
uint32_t pin_cfg = 0;
/* Enabled powersave mode, don't create configuration */
if (!config->powersave) {
/* Enable the pin peripheral MUX flag if non-GPIO selected (pinmux will
* be written later) and store the new MUX mask */
if (config->mux_position != SYSTEM_PINMUX_GPIO) {
pin_cfg |= PORT_WRCONFIG_PMUXEN;
pin_cfg |= (config->mux_position << PORT_WRCONFIG_PMUX_Pos);
}
/* Check if the user has requested that the input buffer be enabled */
if ((config->direction == SYSTEM_PINMUX_PIN_DIR_INPUT) ||
(config->direction == SYSTEM_PINMUX_PIN_DIR_OUTPUT_WITH_READBACK)) {
/* Enable input buffer flag */
pin_cfg |= PORT_WRCONFIG_INEN;
/* Enable pull-up/pull-down control flag if requested */
if (config->input_pull != SYSTEM_PINMUX_PIN_PULL_NONE) {
pin_cfg |= PORT_WRCONFIG_PULLEN;
}
/* Clear the port DIR bits to disable the output buffer */
port->DIRCLR.reg = pin_mask;
}
/* Check if the user has requested that the output buffer be enabled */
if ((config->direction == SYSTEM_PINMUX_PIN_DIR_OUTPUT) ||
(config->direction == SYSTEM_PINMUX_PIN_DIR_OUTPUT_WITH_READBACK)) {
/* Cannot use a pull-up if the output driver is enabled,
* if requested the input buffer can only sample the current
* output state */
pin_cfg &= ~PORT_WRCONFIG_PULLEN;
}
} else {
port->DIRCLR.reg = pin_mask;
}
/* The Write Configuration register (WRCONFIG) requires the
* pins to to grouped into two 16-bit half-words - split them out here */
uint32_t lower_pin_mask = (pin_mask & 0xFFFF);
uint32_t upper_pin_mask = (pin_mask >> 16);
/* Configure the lower 16-bits of the port to the desired configuration,
* including the pin peripheral multiplexer just in case it is enabled */
port->WRCONFIG.reg
= (lower_pin_mask << PORT_WRCONFIG_PINMASK_Pos) |
pin_cfg | PORT_WRCONFIG_WRPMUX | PORT_WRCONFIG_WRPINCFG;
/* Configure the upper 16-bits of the port to the desired configuration,
* including the pin peripheral multiplexer just in case it is enabled */
port->WRCONFIG.reg
= (upper_pin_mask << PORT_WRCONFIG_PINMASK_Pos) |
pin_cfg | PORT_WRCONFIG_WRPMUX | PORT_WRCONFIG_WRPINCFG |
PORT_WRCONFIG_HWSEL;
if(!config->powersave) {
/* Set the pull-up state once the port pins are configured if one was
* requested and it does not violate the valid set of port
* configurations */
if (pin_cfg & PORT_WRCONFIG_PULLEN) {
/* Set the OUT register bits to enable the pull-up if requested,
* clear to enable pull-down */
if (config->input_pull == SYSTEM_PINMUX_PIN_PULL_UP) {
port->OUTSET.reg = pin_mask;
} else {
port->OUTCLR.reg = pin_mask;
}
}
/* Check if the user has requested that the output buffer be enabled */
if ((config->direction == SYSTEM_PINMUX_PIN_DIR_OUTPUT) ||
(config->direction == SYSTEM_PINMUX_PIN_DIR_OUTPUT_WITH_READBACK)) {
/* Set the port DIR bits to enable the output buffer */
port->DIRSET.reg = pin_mask;
}
}
}
/**
* \brief Writes a Port pin configuration to the hardware module.
*
* Writes out a given configuration of a Port pin configuration to the hardware
* module.
*
* \note If the pin direction is set as an output, the pull-up/pull-down input
* configuration setting is ignored.
*
* \param[in] gpio_pin Index of the GPIO pin to configure
* \param[in] config Configuration settings for the pin
*/
void system_pinmux_pin_set_config(
const uint8_t gpio_pin,
const struct system_pinmux_config *const config)
{
PortGroup *const port = system_pinmux_get_group_from_gpio_pin(gpio_pin);
uint32_t pin_mask = (1UL << (gpio_pin % 32));
_system_pinmux_config(port, pin_mask, config);
}