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105 lines
2.5 KiB
105 lines
2.5 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* SIRF hardware spinlock driver |
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* |
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* Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company. |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/device.h> |
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#include <linux/io.h> |
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#include <linux/slab.h> |
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#include <linux/spinlock.h> |
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#include <linux/hwspinlock.h> |
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#include <linux/platform_device.h> |
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#include <linux/of.h> |
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#include <linux/of_address.h> |
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#include "hwspinlock_internal.h" |
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struct sirf_hwspinlock { |
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void __iomem *io_base; |
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struct hwspinlock_device bank; |
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}; |
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/* Number of Hardware Spinlocks*/ |
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#define HW_SPINLOCK_NUMBER 30 |
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/* Hardware spinlock register offsets */ |
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#define HW_SPINLOCK_BASE 0x404 |
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#define HW_SPINLOCK_OFFSET(x) (HW_SPINLOCK_BASE + 0x4 * (x)) |
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static int sirf_hwspinlock_trylock(struct hwspinlock *lock) |
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{ |
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void __iomem *lock_addr = lock->priv; |
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/* attempt to acquire the lock by reading value == 1 from it */ |
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return !!readl(lock_addr); |
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} |
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static void sirf_hwspinlock_unlock(struct hwspinlock *lock) |
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{ |
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void __iomem *lock_addr = lock->priv; |
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/* release the lock by writing 0 to it */ |
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writel(0, lock_addr); |
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} |
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static const struct hwspinlock_ops sirf_hwspinlock_ops = { |
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.trylock = sirf_hwspinlock_trylock, |
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.unlock = sirf_hwspinlock_unlock, |
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}; |
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static int sirf_hwspinlock_probe(struct platform_device *pdev) |
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{ |
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struct sirf_hwspinlock *hwspin; |
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struct hwspinlock *hwlock; |
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int idx; |
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if (!pdev->dev.of_node) |
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return -ENODEV; |
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hwspin = devm_kzalloc(&pdev->dev, |
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struct_size(hwspin, bank.lock, |
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HW_SPINLOCK_NUMBER), |
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GFP_KERNEL); |
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if (!hwspin) |
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return -ENOMEM; |
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/* retrieve io base */ |
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hwspin->io_base = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(hwspin->io_base)) |
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return PTR_ERR(hwspin->io_base); |
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for (idx = 0; idx < HW_SPINLOCK_NUMBER; idx++) { |
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hwlock = &hwspin->bank.lock[idx]; |
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hwlock->priv = hwspin->io_base + HW_SPINLOCK_OFFSET(idx); |
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} |
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platform_set_drvdata(pdev, hwspin); |
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return devm_hwspin_lock_register(&pdev->dev, &hwspin->bank, |
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&sirf_hwspinlock_ops, 0, |
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HW_SPINLOCK_NUMBER); |
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} |
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static const struct of_device_id sirf_hwpinlock_ids[] = { |
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{ .compatible = "sirf,hwspinlock", }, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(of, sirf_hwpinlock_ids); |
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static struct platform_driver sirf_hwspinlock_driver = { |
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.probe = sirf_hwspinlock_probe, |
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.driver = { |
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.name = "atlas7_hwspinlock", |
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.of_match_table = of_match_ptr(sirf_hwpinlock_ids), |
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}, |
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}; |
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module_platform_driver(sirf_hwspinlock_driver); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_DESCRIPTION("SIRF Hardware spinlock driver"); |
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MODULE_AUTHOR("Wei Chen <[email protected]>");
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