Commit 66e012f6 authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'hwlock-v4.21' of git://

Pull hwspinlock updates from Bjorn Andersson:
 "This adds support for the hardware semaphores found in STM32MP1"

* tag 'hwlock-v4.21' of git://
  hwspinlock: fix return value check in stm32_hwspinlock_probe()
  hwspinlock: add STM32 hwspinlock device
  dt-bindings: hwlock: Document STM32 hwspinlock bindings
parents b5aef86e 4d5a91fd
STM32 Hardware Spinlock Device Binding
Required properties :
- compatible : should be "st,stm32-hwspinlock".
- reg : the register address of hwspinlock.
- #hwlock-cells : hwlock users only use the hwlock id to represent a specific
hwlock, so the number of cells should be <1> here.
- clock-names : Must contain "hsem".
- clocks : Must contain a phandle entry for the clock in clock-names, see the
common clock bindings.
Please look at the generic hwlock binding for usage information for consumers,
Example of hwlock provider:
hwspinlock@4c000000 {
compatible = "st,stm32-hwspinlock";
#hwlock-cells = <1>;
reg = <0x4c000000 0x400>;
clocks = <&rcc HSEM>;
clock-names = "hsem";
......@@ -49,6 +49,15 @@ config HWSPINLOCK_SPRD
If unsure, say N.
tristate "STM32 Hardware Spinlock device"
depends on MACH_STM32MP157
depends on HWSPINLOCK
Say y here to support the STM32 Hardware Spinlock device.
If unsure, say N.
config HSEM_U8500
tristate "STE Hardware Semaphore functionality"
depends on HWSPINLOCK
......@@ -8,4 +8,5 @@ obj-$(CONFIG_HWSPINLOCK_OMAP) += omap_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_QCOM) += qcom_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_SIRF) += sirf_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_SPRD) += sprd_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_STM32) += stm32_hwspinlock.o
obj-$(CONFIG_HSEM_U8500) += u8500_hsem.o
// SPDX-License-Identifier: GPL-2.0
* Copyright (C) STMicroelectronics SA 2018
* Author: Benjamin Gaignard <> for STMicroelectronics.
#include <linux/clk.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_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 const struct hwspinlock_ops stm32_hwspinlock_ops = {
.trylock = stm32_hwspinlock_trylock,
.unlock = stm32_hwspinlock_unlock,
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);
ret = hwspin_lock_register(&hw->bank, &pdev->dev, &stm32_hwspinlock_ops,
if (ret)
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);
return 0;
static int __maybe_unused stm32_hwspinlock_runtime_suspend(struct device *dev)
struct stm32_hwspinlock *hw = dev_get_drvdata(dev);
return 0;
static int __maybe_unused stm32_hwspinlock_runtime_resume(struct device *dev)
struct stm32_hwspinlock *hw = dev_get_drvdata(dev);
return 0;
static const struct dev_pm_ops stm32_hwspinlock_pm_ops = {
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 */
static void __exit stm32_hwspinlock_exit(void)
MODULE_DESCRIPTION("Hardware spinlock driver for STM32 SoCs");
MODULE_AUTHOR("Benjamin Gaignard <>");
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