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Diffstat (limited to 'libopencm3/lib/stm32/f1/gpio.c')
| -rw-r--r-- | libopencm3/lib/stm32/f1/gpio.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/libopencm3/lib/stm32/f1/gpio.c b/libopencm3/lib/stm32/f1/gpio.c new file mode 100644 index 0000000..76cbd5b --- /dev/null +++ b/libopencm3/lib/stm32/f1/gpio.c @@ -0,0 +1,194 @@ +/** @defgroup gpio_file GPIO + +@ingroup STM32F1xx + +@brief <b>libopencm3 STM32F1xx General Purpose I/O</b> + +@version 1.0.0 + +@author @htmlonly © @endhtmlonly 2009 +Uwe Hermann <uwe@hermann-uwe.de> +@author @htmlonly © @endhtmlonly 2012 +Ken Sarkies <ksarkies@internode.on.net> + +@date 18 August 2012 + +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 on ports C2 and C9 + +@code + gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_2_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO2 | GPIO9); + gpio_set(GPIOC, GPIO2 | GPIO9); + gpio_clear(GPIOC, GPIO2); + gpio_toggle(GPIOC, GPIO2 | GPIO9); + gpio_port_write(GPIOC, 0x204); +@endcode + +Example 1: Digital input on port C12 + +@code + gpio_set_mode(GPIOC, GPIO_MODE_INPUT, GPIO_CNF_INPUT, GPIO12); + reg16 = gpio_port_read(GPIOC); +@endcode + +LGPL License Terms @ref lgpl_license +*/ +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de> + * + * 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 mode (input/output) and configuration (analog/digitial and +open drain/push pull), 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] cnf Unsigned int8. Pin configuration @ref gpio_cnf +@param[in] gpios Unsigned int16. Pin identifiers @ref gpio_pin_id + If multiple pins are to be set, use logical OR '|' to separate + them. +*/ + +void gpio_set_mode(uint32_t gpioport, uint8_t mode, uint8_t cnf, uint16_t gpios) +{ + uint16_t i, offset = 0; + uint32_t crl = 0, crh = 0, tmp32 = 0; + + /* + * We want to set the config only for the pins mentioned in gpios, + * but keeping the others, so read out the actual config first. + */ + crl = GPIO_CRL(gpioport); + crh = GPIO_CRH(gpioport); + + /* Iterate over all bits, use i as the bitnumber. */ + for (i = 0; i < 16; i++) { + /* Only set the config if the bit is set in gpios. */ + if (!((1 << i) & gpios)) { + continue; + } + + /* Calculate bit offset. */ + offset = (i < 8) ? (i * 4) : ((i - 8) * 4); + + /* Use tmp32 to either modify crl or crh. */ + tmp32 = (i < 8) ? crl : crh; + + /* Modify bits are needed. */ + tmp32 &= ~(0xf << offset); /* Clear the bits first. */ + tmp32 |= (mode << offset) | (cnf << (offset + 2)); + + /* Write tmp32 into crl or crh, leave the other unchanged. */ + crl = (i < 8) ? tmp32 : crl; + crh = (i >= 8) ? tmp32 : crh; + } + + GPIO_CRL(gpioport) = crl; + GPIO_CRH(gpioport) = crh; +} + +/*---------------------------------------------------------------------------*/ +/** @brief Map the EVENTOUT signal + +Enable the EVENTOUT signal and select the port and pin to be used. + +@param[in] evoutport Unsigned int8. Port for EVENTOUT signal @ref afio_evcr_port +@param[in] evoutpin Unsigned int8. Pin for EVENTOUT signal @ref afio_evcr_pin +*/ +void gpio_set_eventout(uint8_t evoutport, uint8_t evoutpin) +{ + AFIO_EVCR = AFIO_EVCR_EVOE | evoutport | evoutpin; +} + +/*---------------------------------------------------------------------------*/ +/** @brief Map Alternate Function Port Bits (Main Set) + +A number of alternate function ports can be remapped to defined alternative +port bits to avoid clashes in cases where multiple alternate functions are +present. Refer to the datasheets for the particular mapping desired. This +provides the main set of remap functionality. See @ref gpio_secondary_remap for +a number of lesser used remaps. + +The AFIO remapping feature is used only with the STM32F10x series. + +@note The Serial Wire JTAG disable controls allow certain GPIO ports to become +available in place of some of the SWJ signals. Full SWJ capability is obtained +by setting this to zero. The value of this must be specified for every call to +this function as its current value cannot be ascertained from the hardware. + +@param[in] swjdisable Unsigned int8. Disable parts of the SWJ capability @ref +afio_swj_disable. +@param[in] maps Unsigned int32. Logical OR of map enable controls from @ref +afio_remap, @ref afio_remap_can1, @ref afio_remap_tim3, @ref afio_remap_tim2, +@ref afio_remap_tim1, @ref afio_remap_usart3. For connectivity line devices +only @ref afio_remap_cld are also available. +*/ +void gpio_primary_remap(uint32_t swjdisable, uint32_t maps) +{ + AFIO_MAPR |= (swjdisable & AFIO_MAPR_SWJ_MASK) | (maps & 0x1FFFFF); +} + +/*---------------------------------------------------------------------------*/ +/** @brief Map Alternate Function Port Bits (Secondary Set) + +A number of alternate function ports can be remapped to defined alternative +port bits to avoid clashes in cases where multiple alternate functions are +present. Refer to the datasheets for the particular mapping desired. This +provides the second smaller and less used set of remap functionality. See @ref +gpio_primary_remap for the main set of remaps. + +The AFIO remapping feature is used only with the STM32F10x series. + +@param[in] maps Unsigned int32. Logical OR of map enable controls from @ref +afio_remap2 +*/ +void gpio_secondary_remap(uint32_t maps) +{ + AFIO_MAPR2 |= maps; +} + +/**@}*/ + |