historical/m0-applesillicon.git/xnu-qemu-arm64-5.1.0/roms/u-boot/arch/arm/mach-davinci/pinmux.c
2024-01-16 11:20:27 -06:00

89 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* DaVinci pinmux functions.
*
* Copyright (C) 2009 Nick Thompson, GE Fanuc Ltd, <nick.thompson@gefanuc.com>
* Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
* Copyright (C) 2008 Lyrtech <www.lyrtech.com>
* Copyright (C) 2004 Texas Instruments.
*/
#include <common.h>
#include <asm/arch/hardware.h>
#include <asm/io.h>
#include <asm/arch/davinci_misc.h>
/*
* Change the setting of a pin multiplexer field.
*
* Takes an array of pinmux settings similar to:
*
* struct pinmux_config uart_pins[] = {
* { &davinci_syscfg_regs->pinmux[8], 2, 7 },
* { &davinci_syscfg_regs->pinmux[9], 2, 0 }
* };
*
* Stepping through the array, each pinmux[n] register has the given value
* set in the pin mux field specified.
*
* The number of pins in the array must be passed (ARRAY_SIZE can provide
* this value conveniently).
*
* Returns 0 if all field numbers and values are in the correct range,
* else returns -1.
*/
int davinci_configure_pin_mux(const struct pinmux_config *pins,
const int n_pins)
{
int i;
/* check for invalid pinmux values */
for (i = 0; i < n_pins; i++) {
if (pins[i].field >= PIN_MUX_NUM_FIELDS ||
(pins[i].value & ~PIN_MUX_FIELD_MASK) != 0)
return -1;
}
/* configure the pinmuxes */
for (i = 0; i < n_pins; i++) {
const int offset = pins[i].field * PIN_MUX_FIELD_SIZE;
const unsigned int value = pins[i].value << offset;
const unsigned int mask = PIN_MUX_FIELD_MASK << offset;
const dv_reg *mux = pins[i].mux;
writel(value | (readl(mux) & (~mask)), mux);
}
return 0;
}
/*
* Configure multiple pinmux resources.
*
* Takes an pinmux_resource array of pinmux_config and pin counts:
*
* const struct pinmux_resource pinmuxes[] = {
* PINMUX_ITEM(uart_pins),
* PINMUX_ITEM(i2c_pins),
* };
*
* The number of items in the array must be passed (ARRAY_SIZE can provide
* this value conveniently).
*
* Each item entry is configured in the defined order. If configuration
* of any item fails, -1 is returned and none of the following items are
* configured. On success, 0 is returned.
*/
int davinci_configure_pin_mux_items(const struct pinmux_resource *item,
const int n_items)
{
int i;
for (i = 0; i < n_items; i++) {
if (davinci_configure_pin_mux(item[i].pins,
item[i].n_pins) != 0)
return -1;
}
return 0;
}