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161 lines
3.8 KiB
161 lines
3.8 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) STMicroelectronics SA 2018 |
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* Author: Benjamin Gaignard <[email protected]> for STMicroelectronics. |
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*/ |
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#include <linux/clk.h> |
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#include <linux/delay.h> |
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#include <linux/hwspinlock.h> |
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#include <linux/io.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/platform_device.h> |
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#include <linux/pm_runtime.h> |
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#include "hwspinlock_internal.h" |
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#define STM32_MUTEX_COREID BIT(8) |
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#define STM32_MUTEX_LOCK_BIT BIT(31) |
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#define STM32_MUTEX_NUM_LOCKS 32 |
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struct stm32_hwspinlock { |
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struct clk *clk; |
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struct hwspinlock_device bank; |
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}; |
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static int stm32_hwspinlock_trylock(struct hwspinlock *lock) |
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{ |
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void __iomem *lock_addr = lock->priv; |
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u32 status; |
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writel(STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID, lock_addr); |
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status = readl(lock_addr); |
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return status == (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID); |
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} |
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static void stm32_hwspinlock_unlock(struct hwspinlock *lock) |
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{ |
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void __iomem *lock_addr = lock->priv; |
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writel(STM32_MUTEX_COREID, lock_addr); |
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} |
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static void stm32_hwspinlock_relax(struct hwspinlock *lock) |
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{ |
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ndelay(50); |
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} |
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static const struct hwspinlock_ops stm32_hwspinlock_ops = { |
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.trylock = stm32_hwspinlock_trylock, |
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.unlock = stm32_hwspinlock_unlock, |
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.relax = stm32_hwspinlock_relax, |
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}; |
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static int stm32_hwspinlock_probe(struct platform_device *pdev) |
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{ |
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struct stm32_hwspinlock *hw; |
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void __iomem *io_base; |
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size_t array_size; |
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int i, ret; |
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io_base = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(io_base)) |
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return PTR_ERR(io_base); |
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array_size = STM32_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock); |
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hw = devm_kzalloc(&pdev->dev, sizeof(*hw) + array_size, GFP_KERNEL); |
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if (!hw) |
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return -ENOMEM; |
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hw->clk = devm_clk_get(&pdev->dev, "hsem"); |
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if (IS_ERR(hw->clk)) |
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return PTR_ERR(hw->clk); |
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for (i = 0; i < STM32_MUTEX_NUM_LOCKS; i++) |
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hw->bank.lock[i].priv = io_base + i * sizeof(u32); |
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platform_set_drvdata(pdev, hw); |
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pm_runtime_enable(&pdev->dev); |
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ret = hwspin_lock_register(&hw->bank, &pdev->dev, &stm32_hwspinlock_ops, |
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0, STM32_MUTEX_NUM_LOCKS); |
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if (ret) |
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pm_runtime_disable(&pdev->dev); |
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return ret; |
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} |
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static int stm32_hwspinlock_remove(struct platform_device *pdev) |
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{ |
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struct stm32_hwspinlock *hw = platform_get_drvdata(pdev); |
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int ret; |
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ret = hwspin_lock_unregister(&hw->bank); |
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if (ret) |
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dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret); |
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pm_runtime_disable(&pdev->dev); |
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return 0; |
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} |
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static int __maybe_unused stm32_hwspinlock_runtime_suspend(struct device *dev) |
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{ |
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struct stm32_hwspinlock *hw = dev_get_drvdata(dev); |
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clk_disable_unprepare(hw->clk); |
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return 0; |
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} |
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static int __maybe_unused stm32_hwspinlock_runtime_resume(struct device *dev) |
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{ |
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struct stm32_hwspinlock *hw = dev_get_drvdata(dev); |
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clk_prepare_enable(hw->clk); |
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return 0; |
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} |
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static const struct dev_pm_ops stm32_hwspinlock_pm_ops = { |
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SET_RUNTIME_PM_OPS(stm32_hwspinlock_runtime_suspend, |
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stm32_hwspinlock_runtime_resume, |
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NULL) |
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}; |
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static const struct of_device_id stm32_hwpinlock_ids[] = { |
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{ .compatible = "st,stm32-hwspinlock", }, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(of, stm32_hwpinlock_ids); |
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static struct platform_driver stm32_hwspinlock_driver = { |
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.probe = stm32_hwspinlock_probe, |
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.remove = stm32_hwspinlock_remove, |
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.driver = { |
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.name = "stm32_hwspinlock", |
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.of_match_table = stm32_hwpinlock_ids, |
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.pm = &stm32_hwspinlock_pm_ops, |
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}, |
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}; |
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static int __init stm32_hwspinlock_init(void) |
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{ |
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return platform_driver_register(&stm32_hwspinlock_driver); |
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} |
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/* board init code might need to reserve hwspinlocks for predefined purposes */ |
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postcore_initcall(stm32_hwspinlock_init); |
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static void __exit stm32_hwspinlock_exit(void) |
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{ |
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platform_driver_unregister(&stm32_hwspinlock_driver); |
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} |
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module_exit(stm32_hwspinlock_exit); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_DESCRIPTION("Hardware spinlock driver for STM32 SoCs"); |
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MODULE_AUTHOR("Benjamin Gaignard <[email protected]>");
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