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