forked from Mirrors/opensbi
bef8f9b806
FDT gpio drivers have an extra .xlate operation, so they need to embed the `struct fdt_driver` inside the subsystem-specific type. The gpio subsystem always initializes the driver for a specific DT node. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org>
92 lines
2.0 KiB
C
92 lines
2.0 KiB
C
/*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*
|
|
* Copyright (c) 2021 Western Digital Corporation or its affiliates.
|
|
*
|
|
* Authors:
|
|
* Anup Patel <anup.patel@wdc.com>
|
|
*/
|
|
|
|
#include <libfdt.h>
|
|
#include <sbi/sbi_error.h>
|
|
#include <sbi_utils/fdt/fdt_helper.h>
|
|
#include <sbi_utils/gpio/fdt_gpio.h>
|
|
|
|
/* List of FDT gpio drivers generated at compile time */
|
|
extern const struct fdt_driver *const fdt_gpio_drivers[];
|
|
|
|
static int fdt_gpio_init(const void *fdt, int nodeoff)
|
|
{
|
|
/* Check "gpio-controller" property */
|
|
if (!fdt_getprop(fdt, nodeoff, "gpio-controller", NULL))
|
|
return SBI_EINVAL;
|
|
|
|
return fdt_driver_init_by_offset(fdt, nodeoff, fdt_gpio_drivers);
|
|
}
|
|
|
|
static int fdt_gpio_chip_find(const void *fdt, int nodeoff,
|
|
struct gpio_chip **out_chip)
|
|
{
|
|
int rc;
|
|
struct gpio_chip *chip = gpio_chip_find(nodeoff);
|
|
|
|
if (!chip) {
|
|
/* GPIO chip not found so initialize matching driver */
|
|
rc = fdt_gpio_init(fdt, nodeoff);
|
|
if (rc)
|
|
return rc;
|
|
|
|
/* Try to find GPIO chip again */
|
|
chip = gpio_chip_find(nodeoff);
|
|
if (!chip)
|
|
return SBI_ENOSYS;
|
|
}
|
|
|
|
if (out_chip)
|
|
*out_chip = chip;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int fdt_gpio_pin_get(const void *fdt, int nodeoff, int index,
|
|
struct gpio_pin *out_pin)
|
|
{
|
|
int rc;
|
|
const struct fdt_gpio *drv;
|
|
struct gpio_chip *chip = NULL;
|
|
struct fdt_phandle_args pargs;
|
|
|
|
if (!fdt || (nodeoff < 0) || (index < 0) || !out_pin)
|
|
return SBI_EINVAL;
|
|
|
|
pargs.node_offset = pargs.args_count = 0;
|
|
rc = fdt_parse_phandle_with_args(fdt, nodeoff,
|
|
"gpios", "#gpio-cells",
|
|
index, &pargs);
|
|
if (rc)
|
|
return rc;
|
|
|
|
rc = fdt_gpio_chip_find(fdt, pargs.node_offset, &chip);
|
|
if (rc)
|
|
return rc;
|
|
|
|
drv = chip->driver;
|
|
if (!drv || !drv->xlate)
|
|
return SBI_ENOSYS;
|
|
|
|
return drv->xlate(chip, &pargs, out_pin);
|
|
}
|
|
|
|
int fdt_gpio_simple_xlate(struct gpio_chip *chip,
|
|
const struct fdt_phandle_args *pargs,
|
|
struct gpio_pin *out_pin)
|
|
{
|
|
if ((pargs->args_count < 2) || (chip->ngpio <= pargs->args[0]))
|
|
return SBI_EINVAL;
|
|
|
|
out_pin->chip = chip;
|
|
out_pin->offset = pargs->args[0];
|
|
out_pin->flags = pargs->args[1];
|
|
return 0;
|
|
}
|