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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * Socfpga Reset Controller Driver
- *
- * Copyright 2014 Steffen Trumtrar <s.trumtrar@pengutronix.de>
- *
- * based on
- * Allwinner SoCs Reset Controller driver
- *
- * Copyright 2013 Maxime Ripard
- *
- * Maxime Ripard <maxime.ripard@free-electrons.com>
- */
- #include <common.h>
- #include <dm.h>
- #include <log.h>
- #include <malloc.h>
- #include <dm/lists.h>
- #include <dm/of_access.h>
- #include <env.h>
- #include <reset-uclass.h>
- #include <wait_bit.h>
- #include <linux/bitops.h>
- #include <linux/io.h>
- #include <linux/sizes.h>
- #define BANK_INCREMENT 4
- #define NR_BANKS 8
- struct socfpga_reset_data {
- void __iomem *modrst_base;
- };
- /*
- * For compatibility with Kernels that don't support peripheral reset, this
- * driver can keep the old behaviour of not asserting peripheral reset before
- * starting the OS and deasserting all peripheral resets (enabling all
- * peripherals).
- *
- * For that, the reset driver checks the environment variable
- * "socfpga_legacy_reset_compat". If this variable is '1', perihperals are not
- * reset again once taken out of reset and all peripherals in 'permodrst' are
- * taken out of reset before booting into the OS.
- * Note that this should be required for gen5 systems only that are running
- * Linux kernels without proper peripheral reset support for all drivers used.
- */
- static bool socfpga_reset_keep_enabled(void)
- {
- #if !defined(CONFIG_SPL_BUILD) || CONFIG_IS_ENABLED(ENV_SUPPORT)
- const char *env_str;
- long val;
- env_str = env_get("socfpga_legacy_reset_compat");
- if (env_str) {
- val = simple_strtol(env_str, NULL, 0);
- if (val == 1)
- return true;
- }
- #endif
- return false;
- }
- static int socfpga_reset_assert(struct reset_ctl *reset_ctl)
- {
- struct socfpga_reset_data *data = dev_get_priv(reset_ctl->dev);
- int id = reset_ctl->id;
- int reg_width = sizeof(u32);
- int bank = id / (reg_width * BITS_PER_BYTE);
- int offset = id % (reg_width * BITS_PER_BYTE);
- setbits_le32(data->modrst_base + (bank * BANK_INCREMENT), BIT(offset));
- return 0;
- }
- static int socfpga_reset_deassert(struct reset_ctl *reset_ctl)
- {
- struct socfpga_reset_data *data = dev_get_priv(reset_ctl->dev);
- int id = reset_ctl->id;
- int reg_width = sizeof(u32);
- int bank = id / (reg_width * BITS_PER_BYTE);
- int offset = id % (reg_width * BITS_PER_BYTE);
- clrbits_le32(data->modrst_base + (bank * BANK_INCREMENT), BIT(offset));
- return wait_for_bit_le32(data->modrst_base + (bank * BANK_INCREMENT),
- BIT(offset),
- false, 500, false);
- }
- static int socfpga_reset_request(struct reset_ctl *reset_ctl)
- {
- debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__,
- reset_ctl, reset_ctl->dev, reset_ctl->id);
- return 0;
- }
- static int socfpga_reset_free(struct reset_ctl *reset_ctl)
- {
- debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
- reset_ctl->dev, reset_ctl->id);
- return 0;
- }
- static const struct reset_ops socfpga_reset_ops = {
- .request = socfpga_reset_request,
- .rfree = socfpga_reset_free,
- .rst_assert = socfpga_reset_assert,
- .rst_deassert = socfpga_reset_deassert,
- };
- static int socfpga_reset_probe(struct udevice *dev)
- {
- struct socfpga_reset_data *data = dev_get_priv(dev);
- u32 modrst_offset;
- void __iomem *membase;
- membase = dev_read_addr_ptr(dev);
- modrst_offset = dev_read_u32_default(dev, "altr,modrst-offset", 0x10);
- data->modrst_base = membase + modrst_offset;
- return 0;
- }
- static int socfpga_reset_remove(struct udevice *dev)
- {
- struct socfpga_reset_data *data = dev_get_priv(dev);
- if (socfpga_reset_keep_enabled()) {
- puts("Deasserting all peripheral resets\n");
- writel(0, data->modrst_base + 4);
- }
- return 0;
- }
- static int socfpga_reset_bind(struct udevice *dev)
- {
- int ret;
- struct udevice *sys_child;
- /*
- * The sysreset driver does not have a device node, so bind it here.
- * Bind it to the node, too, so that it can get its base address.
- */
- ret = device_bind_driver_to_node(dev, "socfpga_sysreset", "sysreset",
- dev_ofnode(dev), &sys_child);
- if (ret)
- debug("Warning: No sysreset driver: ret=%d\n", ret);
- return 0;
- }
- static const struct udevice_id socfpga_reset_match[] = {
- { .compatible = "altr,rst-mgr" },
- { /* sentinel */ },
- };
- U_BOOT_DRIVER(socfpga_reset) = {
- .name = "socfpga-reset",
- .id = UCLASS_RESET,
- .of_match = socfpga_reset_match,
- .bind = socfpga_reset_bind,
- .probe = socfpga_reset_probe,
- .priv_auto = sizeof(struct socfpga_reset_data),
- .ops = &socfpga_reset_ops,
- .remove = socfpga_reset_remove,
- .flags = DM_FLAG_OS_PREPARE,
- };
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