xref: /freebsd-11-stable/sys/dev/sdhci/sdhci_fdt_gpio.h

/*-
 * Copyright (c) 2017 Ian Lepore <ian@freebsd.org>
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 * $FreeBSD: stable/11/sys/dev/sdhci/sdhci_fdt_gpio.h 314508 2017-03-01 20:22:25Z ian $
 */

/*
 * Support routines usable by any SoC sdhci bridge driver that uses gpio pins
 * for card detect and/or write protect, and uses FDT data to describe those
 * pins.  A bridge driver need only supply a couple 2-line forwarding functions
 * to connect the get_present and get_readonly accessors to the corresponding
 * driver interface functions, and add setup/teardown calls to its attach and
 * detach functions.
 */

#ifndef	_SDHCI_FDT_GPIO_H_
#define	_SDHCI_FDT_GPIO_H_

struct sdhci_slot;
struct sdhci_fdt_gpio;

/*
 * sdhci_fdt_gpio_setup()
 * sdhci_fdt_gpio_teardown()
 *
 * Process FDT properties that use gpio pins and set up interrupt handling (if
 * supported by hardware) and accessor functions to read the pins.
 *
 * Setup cannot fail.  If the properties are not present, the accessors will
 * return the values from standard sdhci registers.  If the gpio controller
 * can't trigger interrupts on both edges, it configures the slot to use polling
 * for card presence detection.  If it can't access the gpio pin at all it sets
 * up the get_present() accessor to always return true.  Likewise the
 * get_readonly() accessor always returns false if its pin can't be accessed.
 */
struct sdhci_fdt_gpio *sdhci_fdt_gpio_setup(device_t dev, struct sdhci_slot *slot);
void sdhci_fdt_gpio_teardown(struct sdhci_fdt_gpio *gpio);

/*
 * sdhci_fdt_gpio_get_present()
 * sdhci_fdt_gpio_get_readonly()
 *
 * Gpio pin state accessor functions.
 */
bool sdhci_fdt_gpio_get_present(struct sdhci_fdt_gpio *gpio);
int  sdhci_fdt_gpio_get_readonly(struct sdhci_fdt_gpio *gpio);

#endif