* [PATCH 1/2] hwspinlock: u8500: delete driver
2026-02-10 11:00 [PATCH 0/2] hwspinlock: remove platform_data from subsystem Wolfram Sang
@ 2026-02-10 11:00 ` Wolfram Sang
2026-02-10 11:00 ` [PATCH 2/2] hwspinlock: remove now unused pdata from header file Wolfram Sang
` (2 subsequent siblings)
3 siblings, 0 replies; 7+ messages in thread
From: Wolfram Sang @ 2026-02-10 11:00 UTC (permalink / raw)
To: linux-renesas-soc
Cc: Linus Walleij, Andy Shevchenko, linux-arm-kernel, Wolfram Sang,
Bjorn Andersson, Baolin Wang, linux-remoteproc
The U8500 platform was converted to DT around 2013 and is DT only
meanwhile. This driver has never been converted to a DT driver, so it
clearly hasn't been used since then. To ease upcoming refactoring in the
hwspinlock subsystem, remove this obsolete driver.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
MAINTAINERS | 1 -
drivers/hwspinlock/Kconfig | 10 ---
drivers/hwspinlock/Makefile | 1 -
drivers/hwspinlock/u8500_hsem.c | 155 --------------------------------
4 files changed, 167 deletions(-)
delete mode 100644 drivers/hwspinlock/u8500_hsem.c
diff --git a/MAINTAINERS b/MAINTAINERS
index db2c5a663867..dcdbb7c10dce 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3160,7 +3160,6 @@ F: drivers/clocksource/clksrc-dbx500-prcmu.c
F: drivers/dma/ste_dma40*
F: drivers/pmdomain/st/ste-ux500-pm-domain.c
F: drivers/gpio/gpio-nomadik.c
-F: drivers/hwspinlock/u8500_hsem.c
F: drivers/i2c/busses/i2c-nomadik.c
F: drivers/iio/adc/ab8500-gpadc.c
F: drivers/mfd/ab8500*
diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
index 3874d15b0e9b..d84e00084ee2 100644
--- a/drivers/hwspinlock/Kconfig
+++ b/drivers/hwspinlock/Kconfig
@@ -53,14 +53,4 @@ config HWSPINLOCK_SUN6I
If unsure, say N.
-config HSEM_U8500
- tristate "STE Hardware Semaphore functionality"
- depends on ARCH_U8500 || COMPILE_TEST
- help
- Say y here to support the STE Hardware Semaphore functionality, which
- provides a synchronisation mechanism for the various processor on the
- SoC.
-
- If unsure, say N.
-
endif # HWSPINLOCK
diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
index a0f16c9aaa82..3a740805949d 100644
--- a/drivers/hwspinlock/Makefile
+++ b/drivers/hwspinlock/Makefile
@@ -9,4 +9,3 @@ obj-$(CONFIG_HWSPINLOCK_QCOM) += qcom_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_SPRD) += sprd_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_STM32) += stm32_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_SUN6I) += sun6i_hwspinlock.o
-obj-$(CONFIG_HSEM_U8500) += u8500_hsem.o
diff --git a/drivers/hwspinlock/u8500_hsem.c b/drivers/hwspinlock/u8500_hsem.c
deleted file mode 100644
index 5a2d8c3e0d80..000000000000
--- a/drivers/hwspinlock/u8500_hsem.c
+++ /dev/null
@@ -1,155 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * u8500 HWSEM driver
- *
- * Copyright (C) 2010-2011 ST-Ericsson
- *
- * Implements u8500 semaphore handling for protocol 1, no interrupts.
- *
- * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
- * Heavily borrowed from the work of :
- * Simon Que <sque@ti.com>
- * Hari Kanigeri <h-kanigeri2@ti.com>
- * Ohad Ben-Cohen <ohad@wizery.com>
- */
-
-#include <linux/module.h>
-#include <linux/delay.h>
-#include <linux/io.h>
-#include <linux/slab.h>
-#include <linux/spinlock.h>
-#include <linux/hwspinlock.h>
-#include <linux/platform_device.h>
-
-#include "hwspinlock_internal.h"
-
-/*
- * Implementation of STE's HSem protocol 1 without interrutps.
- * The only masterID we allow is '0x01' to force people to use
- * HSems for synchronisation between processors rather than processes
- * on the ARM core.
- */
-
-#define U8500_MAX_SEMAPHORE 32 /* a total of 32 semaphore */
-#define RESET_SEMAPHORE (0) /* free */
-
-/*
- * CPU ID for master running u8500 kernel.
- * Hswpinlocks should only be used to synchonise operations
- * between the Cortex A9 core and the other CPUs. Hence
- * forcing the masterID to a preset value.
- */
-#define HSEM_MASTER_ID 0x01
-
-#define HSEM_REGISTER_OFFSET 0x08
-
-#define HSEM_CTRL_REG 0x00
-#define HSEM_ICRALL 0x90
-#define HSEM_PROTOCOL_1 0x01
-
-static int u8500_hsem_trylock(struct hwspinlock *lock)
-{
- void __iomem *lock_addr = lock->priv;
-
- writel(HSEM_MASTER_ID, lock_addr);
-
- /* get only first 4 bit and compare to masterID.
- * if equal, we have the semaphore, otherwise
- * someone else has it.
- */
- return (HSEM_MASTER_ID == (0x0F & readl(lock_addr)));
-}
-
-static void u8500_hsem_unlock(struct hwspinlock *lock)
-{
- void __iomem *lock_addr = lock->priv;
-
- /* release the lock by writing 0 to it */
- writel(RESET_SEMAPHORE, lock_addr);
-}
-
-/*
- * u8500: what value is recommended here ?
- */
-static void u8500_hsem_relax(struct hwspinlock *lock)
-{
- ndelay(50);
-}
-
-static const struct hwspinlock_ops u8500_hwspinlock_ops = {
- .trylock = u8500_hsem_trylock,
- .unlock = u8500_hsem_unlock,
- .relax = u8500_hsem_relax,
-};
-
-static int u8500_hsem_probe(struct platform_device *pdev)
-{
- struct hwspinlock_pdata *pdata = pdev->dev.platform_data;
- struct hwspinlock_device *bank;
- struct hwspinlock *hwlock;
- void __iomem *io_base;
- int i, num_locks = U8500_MAX_SEMAPHORE;
- ulong val;
-
- if (!pdata)
- return -ENODEV;
-
- io_base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(io_base))
- return PTR_ERR(io_base);
-
- /* make sure protocol 1 is selected */
- val = readl(io_base + HSEM_CTRL_REG);
- writel((val & ~HSEM_PROTOCOL_1), io_base + HSEM_CTRL_REG);
-
- /* clear all interrupts */
- writel(0xFFFF, io_base + HSEM_ICRALL);
-
- bank = devm_kzalloc(&pdev->dev, struct_size(bank, lock, num_locks),
- GFP_KERNEL);
- if (!bank)
- return -ENOMEM;
-
- platform_set_drvdata(pdev, bank);
-
- for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++)
- hwlock->priv = io_base + HSEM_REGISTER_OFFSET + sizeof(u32) * i;
-
- return devm_hwspin_lock_register(&pdev->dev, bank,
- &u8500_hwspinlock_ops,
- pdata->base_id, num_locks);
-}
-
-static void u8500_hsem_remove(struct platform_device *pdev)
-{
- struct hwspinlock_device *bank = platform_get_drvdata(pdev);
- void __iomem *io_base = bank->lock[0].priv - HSEM_REGISTER_OFFSET;
-
- /* clear all interrupts */
- writel(0xFFFF, io_base + HSEM_ICRALL);
-}
-
-static struct platform_driver u8500_hsem_driver = {
- .probe = u8500_hsem_probe,
- .remove = u8500_hsem_remove,
- .driver = {
- .name = "u8500_hsem",
- },
-};
-
-static int __init u8500_hsem_init(void)
-{
- return platform_driver_register(&u8500_hsem_driver);
-}
-/* board init code might need to reserve hwspinlocks for predefined purposes */
-postcore_initcall(u8500_hsem_init);
-
-static void __exit u8500_hsem_exit(void)
-{
- platform_driver_unregister(&u8500_hsem_driver);
-}
-module_exit(u8500_hsem_exit);
-
-MODULE_LICENSE("GPL v2");
-MODULE_DESCRIPTION("Hardware Spinlock driver for u8500");
-MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
--
2.51.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 2/2] hwspinlock: remove now unused pdata from header file
2026-02-10 11:00 [PATCH 0/2] hwspinlock: remove platform_data from subsystem Wolfram Sang
2026-02-10 11:00 ` [PATCH 1/2] hwspinlock: u8500: delete driver Wolfram Sang
@ 2026-02-10 11:00 ` Wolfram Sang
2026-02-10 14:19 ` [PATCH 0/2] hwspinlock: remove platform_data from subsystem Linus Walleij
2026-02-10 14:56 ` Andy Shevchenko
3 siblings, 0 replies; 7+ messages in thread
From: Wolfram Sang @ 2026-02-10 11:00 UTC (permalink / raw)
To: linux-renesas-soc
Cc: Linus Walleij, Andy Shevchenko, linux-arm-kernel, Wolfram Sang,
Bjorn Andersson, Baolin Wang, linux-remoteproc
The last user turned out to be obsolete and was removed. Remove the
unused struct now, too.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
include/linux/hwspinlock.h | 28 ----------------------------
1 file changed, 28 deletions(-)
diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h
index f35b42e8c5de..74b91244fe0e 100644
--- a/include/linux/hwspinlock.h
+++ b/include/linux/hwspinlock.h
@@ -25,34 +25,6 @@ struct hwspinlock;
struct hwspinlock_device;
struct hwspinlock_ops;
-/**
- * struct hwspinlock_pdata - platform data for hwspinlock drivers
- * @base_id: base id for this hwspinlock device
- *
- * hwspinlock devices provide system-wide hardware locks that are used
- * by remote processors that have no other way to achieve synchronization.
- *
- * To achieve that, each physical lock must have a system-wide id number
- * that is agreed upon, otherwise remote processors can't possibly assume
- * they're using the same hardware lock.
- *
- * Usually boards have a single hwspinlock device, which provides several
- * hwspinlocks, and in this case, they can be trivially numbered 0 to
- * (num-of-locks - 1).
- *
- * In case boards have several hwspinlocks devices, a different base id
- * should be used for each hwspinlock device (they can't all use 0 as
- * a starting id!).
- *
- * This platform data structure should be used to provide the base id
- * for each device (which is trivially 0 when only a single hwspinlock
- * device exists). It can be shared between different platforms, hence
- * its location.
- */
-struct hwspinlock_pdata {
- int base_id;
-};
-
#ifdef CONFIG_HWSPINLOCK
int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,
--
2.51.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH 0/2] hwspinlock: remove platform_data from subsystem
2026-02-10 11:00 [PATCH 0/2] hwspinlock: remove platform_data from subsystem Wolfram Sang
2026-02-10 11:00 ` [PATCH 1/2] hwspinlock: u8500: delete driver Wolfram Sang
2026-02-10 11:00 ` [PATCH 2/2] hwspinlock: remove now unused pdata from header file Wolfram Sang
@ 2026-02-10 14:19 ` Linus Walleij
2026-02-10 14:56 ` Andy Shevchenko
3 siblings, 0 replies; 7+ messages in thread
From: Linus Walleij @ 2026-02-10 14:19 UTC (permalink / raw)
To: Wolfram Sang, Mathieu Poirier
Cc: linux-renesas-soc, Andy Shevchenko, linux-arm-kernel, Baolin Wang,
Bjorn Andersson, linux-remoteproc
On Tue, Feb 10, 2026 at 12:01 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
[Page Mathieu who I think wrote this driver]
> As stated in patch 1, the U8500 driver is clearly unused for more than a
> decade. Removing it allows us to remove generic platform_data support.
> Both removals make the upcoming refactoring (headers and lock
> allocation) in the hwspinlock subsystem easier.
Fair enough, these hwsemaphores were only used when communicating
with two DSPs that we never managed to support upstream.
Reviewed-by: Linus Walleij <linusw@kernel.org>
Yours,
Linus Walleij
^ permalink raw reply [flat|nested] 7+ messages in thread