136 lines
2.8 KiB
C
136 lines
2.8 KiB
C
/*
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* SPDX-License-Identifier: BSD-2-Clause
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*
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* Copyright (c) 2021 Western Digital Corporation or its affiliates.
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*
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* Authors:
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* Anup Patel <anup.patel@wdc.com>
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*/
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#include <libfdt.h>
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#include <sbi/sbi_error.h>
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#include <sbi_utils/fdt/fdt_helper.h>
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#include <sbi_utils/gpio/fdt_gpio.h>
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extern struct fdt_gpio fdt_gpio_sifive;
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static struct fdt_gpio *gpio_drivers[] = {
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&fdt_gpio_sifive
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};
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static struct fdt_gpio *fdt_gpio_driver(struct gpio_chip *chip)
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{
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int pos;
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if (!chip)
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return NULL;
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for (pos = 0; pos < array_size(gpio_drivers); pos++) {
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if (chip->driver == gpio_drivers[pos])
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return gpio_drivers[pos];
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}
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return NULL;
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}
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static int fdt_gpio_init(void *fdt, u32 phandle)
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{
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int pos, nodeoff, rc;
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struct fdt_gpio *drv;
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const struct fdt_match *match;
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/* Find node offset */
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nodeoff = fdt_node_offset_by_phandle(fdt, phandle);
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if (nodeoff < 0)
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return nodeoff;
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/* Check "gpio-controller" property */
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if (!fdt_getprop(fdt, nodeoff, "gpio-controller", &rc))
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return SBI_EINVAL;
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/* Try all GPIO drivers one-by-one */
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for (pos = 0; pos < array_size(gpio_drivers); pos++) {
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drv = gpio_drivers[pos];
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match = fdt_match_node(fdt, nodeoff, drv->match_table);
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if (match && drv->init) {
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rc = drv->init(fdt, nodeoff, phandle, match);
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if (rc == SBI_ENODEV)
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continue;
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if (rc)
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return rc;
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return 0;
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}
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}
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return SBI_ENOSYS;
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}
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static int fdt_gpio_chip_find(void *fdt, u32 phandle,
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struct gpio_chip **out_chip)
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{
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int rc;
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struct gpio_chip *chip = gpio_chip_find(phandle);
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if (!chip) {
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/* GPIO chip not found so initialize matching driver */
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rc = fdt_gpio_init(fdt, phandle);
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if (rc)
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return rc;
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/* Try to find GPIO chip again */
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chip = gpio_chip_find(phandle);
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if (!chip)
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return SBI_ENOSYS;
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}
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if (out_chip)
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*out_chip = chip;
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return 0;
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}
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int fdt_gpio_pin_get(void *fdt, int nodeoff, int index,
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struct gpio_pin *out_pin)
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{
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int rc;
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u32 phandle;
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struct fdt_gpio *drv;
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struct gpio_chip *chip = NULL;
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struct fdt_phandle_args pargs;
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if (!fdt || (nodeoff < 0) || (index < 0) || !out_pin)
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return SBI_EINVAL;
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pargs.node_offset = pargs.args_count = 0;
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rc = fdt_parse_phandle_with_args(fdt, nodeoff,
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"gpios", "#gpio-cells",
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index, &pargs);
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if (rc)
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return rc;
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phandle = fdt_get_phandle(fdt, pargs.node_offset);
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rc = fdt_gpio_chip_find(fdt, phandle, &chip);
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if (rc)
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return rc;
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drv = fdt_gpio_driver(chip);
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if (!drv || !drv->xlate)
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return SBI_ENOSYS;
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return drv->xlate(chip, &pargs, out_pin);
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}
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int fdt_gpio_simple_xlate(struct gpio_chip *chip,
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const struct fdt_phandle_args *pargs,
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struct gpio_pin *out_pin)
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{
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if ((pargs->args_count < 2) || (chip->ngpio <= pargs->args[0]))
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return SBI_EINVAL;
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out_pin->chip = chip;
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out_pin->offset = pargs->args[0];
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out_pin->flags = pargs->args[1];
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return 0;
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}
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