tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
reset: add the Berlin reset controller driver
Add a reset controller for Marvell Berlin SoCs which is used by the
USB PHYs drivers (for now).
Signed-off-by: Antoine Ténart <antoine.tenart@free-electrons.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
authored by
Antoine Ténart
and committed by
Sebastian Hesselbarth
bd13251f
f114040e
+132
+1
drivers/reset/Makefile
+1
drivers/reset/Makefile
+131
drivers/reset/reset-berlin.c
+131
drivers/reset/reset-berlin.c
···
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/*
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* Copyright (C) 2014 Marvell Technology Group Ltd.
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*
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* Antoine Tenart <antoine.tenart@free-electrons.com>
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* Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/delay.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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#include <linux/reset-controller.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#define BERLIN_MAX_RESETS 32
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#define to_berlin_reset_priv(p) \
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container_of((p), struct berlin_reset_priv, rcdev)
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struct berlin_reset_priv {
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void __iomem *base;
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unsigned int size;
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struct reset_controller_dev rcdev;
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};
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static int berlin_reset_reset(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
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int offset = id >> 8;
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int mask = BIT(id & 0x1f);
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writel(mask, priv->base + offset);
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/* let the reset be effective */
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udelay(10);
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return 0;
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}
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static struct reset_control_ops berlin_reset_ops = {
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.reset = berlin_reset_reset,
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};
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static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
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const struct of_phandle_args *reset_spec)
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{
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struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
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unsigned offset, bit;
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if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
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return -EINVAL;
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offset = reset_spec->args[0];
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bit = reset_spec->args[1];
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if (offset >= priv->size)
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return -EINVAL;
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if (bit >= BERLIN_MAX_RESETS)
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return -EINVAL;
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return (offset << 8) | bit;
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}
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static int __berlin_reset_init(struct device_node *np)
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{
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struct berlin_reset_priv *priv;
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struct resource res;
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resource_size_t size;
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int ret;
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priv = kzalloc(sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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ret = of_address_to_resource(np, 0, &res);
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if (ret)
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goto err;
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size = resource_size(&res);
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priv->base = ioremap(res.start, size);
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if (!priv->base) {
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ret = -ENOMEM;
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goto err;
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}
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priv->size = size;
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priv->rcdev.owner = THIS_MODULE;
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priv->rcdev.ops = &berlin_reset_ops;
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priv->rcdev.of_node = np;
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priv->rcdev.of_reset_n_cells = 2;
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priv->rcdev.of_xlate = berlin_reset_xlate;
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reset_controller_register(&priv->rcdev);
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return 0;
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err:
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kfree(priv);
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return ret;
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}
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static const struct of_device_id berlin_reset_of_match[] __initconst = {
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{ .compatible = "marvell,berlin2-chip-ctrl" },
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{ .compatible = "marvell,berlin2cd-chip-ctrl" },
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{ .compatible = "marvell,berlin2q-chip-ctrl" },
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{ },
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};
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static int __init berlin_reset_init(void)
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{
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struct device_node *np;
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int ret;
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for_each_matching_node(np, berlin_reset_of_match) {
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ret = __berlin_reset_init(np);
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if (ret)
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return ret;
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}
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return 0;
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}
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arch_initcall(berlin_reset_init);