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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208// SPDX-License-Identifier: GPL-2.0-or-later/* * Simple Reset Controller Driver * * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de> * * Based on Allwinner SoCs Reset Controller driver * * Copyright 2013 Maxime Ripard * * Maxime Ripard <maxime.ripard@free-electrons.com> */
#include <linux/delay.h>#include <linux/device.h>#include <linux/err.h>#include <linux/io.h>#include <linux/of.h>#include <linux/platform_device.h>#include <linux/reset-controller.h>#include <linux/reset/reset-simple.h>#include <linux/spinlock.h>
static inline struct reset_simple_data *to_reset_simple_data(struct reset_controller_dev *rcdev){ return container_of(rcdev, struct reset_simple_data, rcdev);}
static int reset_simple_update(struct reset_controller_dev *rcdev, unsigned long id, bool assert){ struct reset_simple_data *data = to_reset_simple_data(rcdev); int reg_width = sizeof(u32); int bank = id / (reg_width * BITS_PER_BYTE); int offset = id % (reg_width * BITS_PER_BYTE); unsigned long flags; u32 reg;
spin_lock_irqsave(&data->lock, flags);
reg = readl(data->membase + (bank * reg_width)); if (assert ^ data->active_low) reg |= BIT(offset); else reg &= ~BIT(offset); writel(reg, data->membase + (bank * reg_width));
spin_unlock_irqrestore(&data->lock, flags);
return 0;}
static int reset_simple_assert(struct reset_controller_dev *rcdev, unsigned long id){ return reset_simple_update(rcdev, id, true);}
static int reset_simple_deassert(struct reset_controller_dev *rcdev, unsigned long id){ return reset_simple_update(rcdev, id, false);}
static int reset_simple_reset(struct reset_controller_dev *rcdev, unsigned long id){ struct reset_simple_data *data = to_reset_simple_data(rcdev); int ret;
if (!data->reset_us) return -ENOTSUPP;
ret = reset_simple_assert(rcdev, id); if (ret) return ret;
usleep_range(data->reset_us, data->reset_us * 2);
return reset_simple_deassert(rcdev, id);}
static int reset_simple_status(struct reset_controller_dev *rcdev, unsigned long id){ struct reset_simple_data *data = to_reset_simple_data(rcdev); int reg_width = sizeof(u32); int bank = id / (reg_width * BITS_PER_BYTE); int offset = id % (reg_width * BITS_PER_BYTE); u32 reg;
reg = readl(data->membase + (bank * reg_width));
return !(reg & BIT(offset)) ^ !data->status_active_low;}
const struct reset_control_ops reset_simple_ops = { .assert = reset_simple_assert, .deassert = reset_simple_deassert, .reset = reset_simple_reset, .status = reset_simple_status,};EXPORT_SYMBOL_GPL(reset_simple_ops);
/** * struct reset_simple_devdata - simple reset controller properties * @reg_offset: offset between base address and first reset register. * @nr_resets: number of resets. If not set, default to resource size in bits. * @active_low: if true, bits are cleared to assert the reset. Otherwise, bits * are set to assert the reset. * @status_active_low: if true, bits read back as cleared while the reset is * asserted. Otherwise, bits read back as set while the * reset is asserted. */struct reset_simple_devdata { u32 reg_offset; u32 nr_resets; bool active_low; bool status_active_low;};
#define SOCFPGA_NR_BANKS 8
static const struct reset_simple_devdata reset_simple_socfpga = { .reg_offset = 0x20, .nr_resets = SOCFPGA_NR_BANKS * 32, .status_active_low = true,};
static const struct reset_simple_devdata reset_simple_active_low = { .active_low = true, .status_active_low = true,};
static const struct of_device_id reset_simple_dt_ids[] = { { .compatible = "altr,stratix10-rst-mgr", .data = &reset_simple_socfpga }, { .compatible = "st,stm32-rcc", }, { .compatible = "allwinner,sun6i-a31-clock-reset", .data = &reset_simple_active_low }, { .compatible = "zte,zx296718-reset", .data = &reset_simple_active_low }, { .compatible = "aspeed,ast2400-lpc-reset" }, { .compatible = "aspeed,ast2500-lpc-reset" }, { .compatible = "aspeed,ast2600-lpc-reset" }, { .compatible = "bitmain,bm1880-reset", .data = &reset_simple_active_low }, { .compatible = "brcm,bcm4908-misc-pcie-reset", .data = &reset_simple_active_low }, { .compatible = "snps,dw-high-reset" }, { .compatible = "snps,dw-low-reset", .data = &reset_simple_active_low }, { .compatible = "sophgo,cv1800b-reset", .data = &reset_simple_active_low }, { .compatible = "sophgo,sg2042-reset", .data = &reset_simple_active_low }, { /* sentinel */ },};
static int reset_simple_probe(struct platform_device *pdev){ struct device *dev = &pdev->dev; const struct reset_simple_devdata *devdata; struct reset_simple_data *data; void __iomem *membase; struct resource *res; u32 reg_offset = 0;
devdata = of_device_get_match_data(dev);
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM;
membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res); if (IS_ERR(membase)) return PTR_ERR(membase);
spin_lock_init(&data->lock); data->membase = membase; data->rcdev.owner = THIS_MODULE; data->rcdev.nr_resets = resource_size(res) * BITS_PER_BYTE; data->rcdev.ops = &reset_simple_ops; data->rcdev.of_node = dev->of_node;
if (devdata) { reg_offset = devdata->reg_offset; if (devdata->nr_resets) data->rcdev.nr_resets = devdata->nr_resets; data->active_low = devdata->active_low; data->status_active_low = devdata->status_active_low; }
data->membase += reg_offset;
return devm_reset_controller_register(dev, &data->rcdev);}
static struct platform_driver reset_simple_driver = { .probe = reset_simple_probe, .driver = { .name = "simple-reset", .of_match_table = reset_simple_dt_ids, },};builtin_platform_driver(reset_simple_driver);