0a8bd97f88
The I2C driver shares a reset line between buses, so allow it to test the state of the reset line before resetting it. Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Ryan Chen <ryan_chen@aspeedtech.com>
111 lines
2.6 KiB
C
111 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright 2017 Google, Inc
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* Copyright 2020 ASPEED Technology Inc.
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*/
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#include <common.h>
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#include <dm.h>
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#include <log.h>
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#include <misc.h>
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#include <reset.h>
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#include <reset-uclass.h>
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#include <linux/err.h>
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#include <asm/io.h>
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#include <asm/arch/scu_ast2500.h>
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struct ast2500_reset_priv {
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struct ast2500_scu *scu;
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};
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static int ast2500_reset_assert(struct reset_ctl *reset_ctl)
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{
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struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
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struct ast2500_scu *scu = priv->scu;
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debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
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if (reset_ctl->id < 32)
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setbits_le32(&scu->sysreset_ctrl1, BIT(reset_ctl->id));
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else
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setbits_le32(&scu->sysreset_ctrl2, BIT(reset_ctl->id - 32));
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return 0;
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}
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static int ast2500_reset_deassert(struct reset_ctl *reset_ctl)
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{
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struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
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struct ast2500_scu *scu = priv->scu;
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debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
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if (reset_ctl->id < 32)
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clrbits_le32(&scu->sysreset_ctrl1, BIT(reset_ctl->id));
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else
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clrbits_le32(&scu->sysreset_ctrl2, BIT(reset_ctl->id - 32));
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return 0;
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}
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static int ast2500_reset_status(struct reset_ctl *reset_ctl)
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{
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struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
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struct ast2500_scu *scu = priv->scu;
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int status;
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debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
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if (reset_ctl->id < 32)
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status = BIT(reset_ctl->id) & readl(&scu->sysreset_ctrl1);
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else
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status = BIT(reset_ctl->id - 32) & readl(&scu->sysreset_ctrl2);
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return !!status;
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}
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static int ast2500_reset_probe(struct udevice *dev)
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{
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int rc;
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struct ast2500_reset_priv *priv = dev_get_priv(dev);
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struct udevice *scu_dev;
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/* get SCU base from clock device */
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rc = uclass_get_device_by_driver(UCLASS_CLK,
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DM_DRIVER_GET(aspeed_ast2500_scu), &scu_dev);
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if (rc) {
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debug("%s: clock device not found, rc=%d\n", __func__, rc);
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return rc;
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}
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priv->scu = devfdt_get_addr_ptr(scu_dev);
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if (IS_ERR_OR_NULL(priv->scu)) {
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debug("%s: invalid SCU base pointer\n", __func__);
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return PTR_ERR(priv->scu);
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}
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return 0;
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}
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static const struct udevice_id ast2500_reset_ids[] = {
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{ .compatible = "aspeed,ast2500-reset" },
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{ }
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};
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struct reset_ops ast2500_reset_ops = {
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.rst_assert = ast2500_reset_assert,
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.rst_deassert = ast2500_reset_deassert,
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.rst_status = ast2500_reset_status,
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};
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U_BOOT_DRIVER(ast2500_reset) = {
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.name = "ast2500_reset",
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.id = UCLASS_RESET,
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.of_match = ast2500_reset_ids,
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.probe = ast2500_reset_probe,
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.ops = &ast2500_reset_ops,
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.priv_auto = sizeof(struct ast2500_reset_priv),
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};
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