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	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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| 
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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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| 
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| struct ast2500_reset_priv {
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| 	struct ast2500_scu *scu;
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| };
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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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| 
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| 	debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
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| 
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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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| 
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| 	return 0;
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| }
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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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| 
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| 	debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
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| 
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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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| 
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| 	return 0;
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| }
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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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| 
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| 	debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
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| 
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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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| 
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| 	return !!status;
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| }
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| 
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| 
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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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| 
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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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| 
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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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| 
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| 	return 0;
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| }
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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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| 
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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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| 
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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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