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Diffstat (limited to 'libopencm3/lib/stm32/common/gpio_common_f0234.c')
| -rw-r--r-- | libopencm3/lib/stm32/common/gpio_common_f0234.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/libopencm3/lib/stm32/common/gpio_common_f0234.c b/libopencm3/lib/stm32/common/gpio_common_f0234.c new file mode 100644 index 0000000..9d79074 --- /dev/null +++ b/libopencm3/lib/stm32/common/gpio_common_f0234.c @@ -0,0 +1,206 @@ +/** @addtogroup gpio_file + +@author @htmlonly © @endhtmlonly 2009 +Uwe Hermann <uwe@hermann-uwe.de> +@author @htmlonly © @endhtmlonly 2012 +Ken Sarkies <ksarkies@internode.on.net> + +Each I/O port has 16 individually configurable bits. Many I/O pins share GPIO +functionality with a number of alternate functions and must be configured to +the alternate function mode if these are to be accessed. A feature is available +to remap alternative functions to a limited set of alternative pins in the +event of a clash of requirements. + +The data registers associated with each port for input and output are 32 bit +with the upper 16 bits unused. The output buffer must be written as a 32 bit +word, but individual bits may be set or reset separately in atomic operations +to avoid race conditions during interrupts. Bits may also be individually +locked to prevent accidental configuration changes. Once locked the +configuration cannot be changed until after the next reset. + +Each port bit can be configured as analog or digital input, the latter can be +floating or pulled up or down. As outputs they can be configured as either +push-pull or open drain, digital I/O or alternate function, and with maximum +output speeds of 2MHz, 10MHz, or 50MHz. + +On reset all ports are configured as digital floating input. + +@section gpio_api_ex Basic GPIO Handling API. + +Example 1: Push-pull digital output actions with pullup on ports C2 and C9 + +@code + gpio_mode_setup(GPIOC, GPIO_MODE_OUTPUT, + GPIO_PUPD_PULLUP, GPIO2 | GPIO9); + gpio_output_options(GPIOC, GPIO_OTYPE_PP, + GPIO_OSPEED_25MHZ, GPIO2 | GPIO9); + gpio_set(GPIOC, GPIO2 | GPIO9); + gpio_clear(GPIOC, GPIO2); + gpio_toggle(GPIOC, GPIO2 | GPIO9); + gpio_port_write(GPIOC, 0x204); +@endcode + +Example 2: Digital input on port C12 with pullup + +@code + gpio_mode_setup(GPIOC, GPIO_MODE_INPUT, + GPIO_PUPD_PULLUP, GPIO12); + reg16 = gpio_port_read(GPIOC); +@endcode + +*/ +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2011 Fergus Noble <fergusnoble@gmail.com> + * + * This library is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this library. If not, see <http://www.gnu.org/licenses/>. + */ + +/**@{*/ + +#include <libopencm3/stm32/gpio.h> + +/*---------------------------------------------------------------------------*/ +/** @brief Set GPIO Pin Mode + +Sets the Pin Direction and Analog/Digital Mode, and Output Pin Pullup, +for a set of GPIO pins on a given GPIO port. + +@param[in] gpioport Unsigned int32. Port identifier @ref gpio_port_id +@param[in] mode Unsigned int8. Pin mode @ref gpio_mode +@param[in] pull_up_down Unsigned int8. Pin pullup/pulldown configuration @ref +gpio_pup +@param[in] gpios Unsigned int16. Pin identifiers @ref gpio_pin_id + If multiple pins are to be set, use bitwise OR '|' to separate + them. +*/ +void gpio_mode_setup(uint32_t gpioport, uint8_t mode, uint8_t pull_up_down, + uint16_t gpios) +{ + uint16_t i; + uint32_t moder, pupd; + + /* + * We want to set the config only for the pins mentioned in gpios, + * but keeping the others, so read out the actual config first. + */ + moder = GPIO_MODER(gpioport); + pupd = GPIO_PUPDR(gpioport); + + for (i = 0; i < 16; i++) { + if (!((1 << i) & gpios)) { + continue; + } + + moder &= ~GPIO_MODE_MASK(i); + moder |= GPIO_MODE(i, mode); + pupd &= ~GPIO_PUPD_MASK(i); + pupd |= GPIO_PUPD(i, pull_up_down); + } + + /* Set mode and pull up/down control registers. */ + GPIO_MODER(gpioport) = moder; + GPIO_PUPDR(gpioport) = pupd; +} + +/*---------------------------------------------------------------------------*/ +/** @brief Set GPIO Output Options + +When the pin is set to output mode, this sets the configuration (analog/digital +and open drain/push pull) and speed, for a set of GPIO pins on a given GPIO +port. + +@param[in] gpioport Unsigned int32. Port identifier @ref gpio_port_id +@param[in] otype Unsigned int8. Pin output type @ref gpio_output_type +@param[in] speed Unsigned int8. Pin speed @ref gpio_speed +@param[in] gpios Unsigned int16. Pin identifiers @ref gpio_pin_id + If multiple pins are to be set, use bitwise OR '|' to separate + them. +*/ +void gpio_set_output_options(uint32_t gpioport, uint8_t otype, uint8_t speed, + uint16_t gpios) +{ + uint16_t i; + uint32_t ospeedr; + + if (otype == 0x1) { + GPIO_OTYPER(gpioport) |= gpios; + } else { + GPIO_OTYPER(gpioport) &= ~gpios; + } + + ospeedr = GPIO_OSPEEDR(gpioport); + + for (i = 0; i < 16; i++) { + if (!((1 << i) & gpios)) { + continue; + } + ospeedr &= ~GPIO_OSPEED_MASK(i); + ospeedr |= GPIO_OSPEED(i, speed); + } + + GPIO_OSPEEDR(gpioport) = ospeedr; +} + +/*---------------------------------------------------------------------------*/ +/** @brief Set GPIO Alternate Function Selection + +Set the alternate function mapping number for each pin. Most pins have +alternate functions associated with them. When set to AF mode, a pin may be +used for one of its allocated alternate functions selected by the number given +here. To determine the number to be used for the desired function refer to the +individual datasheet for the particular device. A table is given under the Pin +Selection chapter. + +Note that a number of pins may be set but only with a single AF number. In +practice this would rarely be useful as each pin is likely to require a +different number. + +@param[in] gpioport Unsigned int32. Port identifier @ref gpio_port_id +@param[in] alt_func_num Unsigned int8. Pin alternate function number @ref +gpio_af_num +@param[in] gpios Unsigned int16. Pin identifiers @ref gpio_pin_id + If multiple pins are to be set, use bitwise OR '|' to separate + them. +*/ +void gpio_set_af(uint32_t gpioport, uint8_t alt_func_num, uint16_t gpios) +{ + uint16_t i; + uint32_t afrl, afrh; + + afrl = GPIO_AFRL(gpioport); + afrh = GPIO_AFRH(gpioport); + + for (i = 0; i < 8; i++) { + if (!((1 << i) & gpios)) { + continue; + } + afrl &= ~GPIO_AFR_MASK(i); + afrl |= GPIO_AFR(i, alt_func_num); + } + + for (i = 8; i < 16; i++) { + if (!((1 << i) & gpios)) { + continue; + } + afrh &= ~GPIO_AFR_MASK(i - 8); + afrh |= GPIO_AFR(i - 8, alt_func_num); + } + + GPIO_AFRL(gpioport) = afrl; + GPIO_AFRH(gpioport) = afrh; +} +/**@}*/ + |