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Subject[RFC 2/5] hwspinlock: Add Realtek RTD1195 SB2
Date
Implement a driver for hardware semaphores found in RTD1195 SoC.
It allows for both per-register instances (SB2_HD_SEM) as well as
contiguous register ranges (SB2_HD_SEM_NEW[0-7]).

While these registers are part of the SB2 syscon, this implementation
does not use syscon, to allow assigning one as SB2 syscon's hwlock.

Cc: Cheng-Yu Lee <cylee12@realtek.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
---
drivers/hwspinlock/Kconfig | 11 ++++
drivers/hwspinlock/Makefile | 1 +
drivers/hwspinlock/rtd1195_sb2_sem.c | 101 +++++++++++++++++++++++++++++++++++
3 files changed, 113 insertions(+)
create mode 100644 drivers/hwspinlock/rtd1195_sb2_sem.c

diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
index 37740e992cfa..9c26c436d399 100644
--- a/drivers/hwspinlock/Kconfig
+++ b/drivers/hwspinlock/Kconfig
@@ -28,6 +28,17 @@ config HWSPINLOCK_QCOM

If unsure, say N.

+config HWSPINLOCK_RTD1195_SB2
+ tristate "Realtek RTD1195 SB2 Hardware Spinlock device"
+ depends on HWSPINLOCK
+ depends on ARCH_REALTEK || COMPILE_TEST
+ default ARCH_REALTEK
+ help
+ Say y here to support the Realtek Hardware Semaphore functionality,
+ found on the RTD1195 and later SoC families.
+
+ If unsure, say N.
+
config HWSPINLOCK_SIRF
tristate "SIRF Hardware Spinlock device"
depends on HWSPINLOCK
diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
index ed053e3f02be..d5bd59412468 100644
--- a/drivers/hwspinlock/Makefile
+++ b/drivers/hwspinlock/Makefile
@@ -6,6 +6,7 @@
obj-$(CONFIG_HWSPINLOCK) += hwspinlock_core.o
obj-$(CONFIG_HWSPINLOCK_OMAP) += omap_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_QCOM) += qcom_hwspinlock.o
+obj-$(CONFIG_HWSPINLOCK_RTD1195_SB2) += rtd1195_sb2_sem.o
obj-$(CONFIG_HWSPINLOCK_SIRF) += sirf_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_SPRD) += sprd_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_STM32) += stm32_hwspinlock.o
diff --git a/drivers/hwspinlock/rtd1195_sb2_sem.c b/drivers/hwspinlock/rtd1195_sb2_sem.c
new file mode 100644
index 000000000000..ae925d057874
--- /dev/null
+++ b/drivers/hwspinlock/rtd1195_sb2_sem.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RTD1195 SB2 hardware semaphore
+ *
+ * Copyright (c) 2019 Andreas Färber
+ */
+
+#include <linux/bitops.h>
+#include <linux/hwspinlock.h>
+#include <linux/idr.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+
+#include "hwspinlock_internal.h"
+
+struct rtd1195_sb2_sem {
+ struct platform_device *pdev;
+ void __iomem *base;
+ int base_id;
+ struct hwspinlock_device lockdev;
+};
+
+static DEFINE_IDR(rtd1195_sb2_sem_idr);
+
+static int rtd1195_sb2_sem_trylock(struct hwspinlock *lock)
+{
+ void __iomem *reg = (void __iomem *)lock->priv;
+
+ return readl_relaxed(reg) & BIT(0);
+}
+
+static void rtd1195_sb2_sem_unlock(struct hwspinlock *lock)
+{
+ void __iomem *reg = (void __iomem *)lock->priv;
+
+ writel_relaxed(0, reg);
+}
+
+static const struct hwspinlock_ops rtd1195_sb2_sem_hwspinlock_ops = {
+ .trylock = rtd1195_sb2_sem_trylock,
+ .unlock = rtd1195_sb2_sem_unlock,
+};
+
+static int rtd1195_sb2_sem_probe(struct platform_device *pdev)
+{
+ struct rtd1195_sb2_sem *sem;
+ struct hwspinlock *lock;
+ struct resource *res;
+ int i, num;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENOMEM;
+
+ num = resource_size(res) / 4;
+
+ sem = devm_kzalloc(&pdev->dev, sizeof(*sem) + num * sizeof(*lock),
+ GFP_KERNEL);
+ if (!sem)
+ return -ENOMEM;
+
+ sem->pdev = pdev;
+
+ sem->base = of_iomap(pdev->dev.of_node, 0);
+ if (!sem->base)
+ return -ENOMEM;
+
+ for (i = 0; i < num; i++) {
+ lock = &sem->lockdev.lock[i];
+ lock->priv = sem->base + i * 4;
+ }
+
+ platform_set_drvdata(pdev, sem);
+
+ sem->base_id = idr_alloc(&rtd1195_sb2_sem_idr, sem, 0, 0, GFP_KERNEL);
+
+ return devm_hwspin_lock_register(&pdev->dev, &sem->lockdev,
+ &rtd1195_sb2_sem_hwspinlock_ops, sem->base_id, num);
+}
+
+static const struct of_device_id rtd1195_sb2_sem_dt_ids[] = {
+ { .compatible = "realtek,rtd1195-sb2-sem" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, rtd1195_sb2_sem_dt_ids);
+
+static struct platform_driver rtd1195_sb2_sem_platform_driver = {
+ .driver = {
+ .name = "rtd1195-sb2-sem",
+ .of_match_table = rtd1195_sb2_sem_dt_ids,
+ },
+ .probe = rtd1195_sb2_sem_probe,
+};
+module_platform_driver(rtd1195_sb2_sem_platform_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Hardware spinlock driver for Realtek RTD1195 SB2");
+MODULE_AUTHOR("Andreas Färber <afaerber@suse.de>");
--
2.16.4
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