u-boot/drivers/hwspinlock/stm32_hwspinlock.c
Benjamin Gaignard 9119f547d3 hwspinlock: add stm32 hardware spinlock support
Implement hardware spinlock support for STM32MP1.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
2018-12-06 23:26:33 -05:00

93 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
/*
* Copyright (C) 2018, STMicroelectronics - All Rights Reserved
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <hwspinlock.h>
#include <asm/io.h>
#define STM32_MUTEX_COREID BIT(8)
#define STM32_MUTEX_LOCK_BIT BIT(31)
#define STM32_MUTEX_NUM_LOCKS 32
struct stm32mp1_hws_priv {
fdt_addr_t base;
};
static int stm32mp1_lock(struct udevice *dev, int index)
{
struct stm32mp1_hws_priv *priv = dev_get_priv(dev);
u32 status;
if (index >= STM32_MUTEX_NUM_LOCKS)
return -EINVAL;
status = readl(priv->base + index * sizeof(u32));
if (status == (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID))
return -EBUSY;
writel(STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID,
priv->base + index * sizeof(u32));
status = readl(priv->base + index * sizeof(u32));
if (status != (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID))
return -EINVAL;
return 0;
}
static int stm32mp1_unlock(struct udevice *dev, int index)
{
struct stm32mp1_hws_priv *priv = dev_get_priv(dev);
if (index >= STM32_MUTEX_NUM_LOCKS)
return -EINVAL;
writel(STM32_MUTEX_COREID, priv->base + index * sizeof(u32));
return 0;
}
static int stm32mp1_hwspinlock_probe(struct udevice *dev)
{
struct stm32mp1_hws_priv *priv = dev_get_priv(dev);
struct clk clk;
int ret;
priv->base = dev_read_addr(dev);
if (priv->base == FDT_ADDR_T_NONE)
return -EINVAL;
ret = clk_get_by_index(dev, 0, &clk);
if (ret)
return ret;
ret = clk_enable(&clk);
if (ret)
clk_free(&clk);
return ret;
}
static const struct hwspinlock_ops stm32mp1_hwspinlock_ops = {
.lock = stm32mp1_lock,
.unlock = stm32mp1_unlock,
};
static const struct udevice_id stm32mp1_hwspinlock_ids[] = {
{ .compatible = "st,stm32-hwspinlock" },
{}
};
U_BOOT_DRIVER(hwspinlock_stm32mp1) = {
.name = "hwspinlock_stm32mp1",
.id = UCLASS_HWSPINLOCK,
.of_match = stm32mp1_hwspinlock_ids,
.ops = &stm32mp1_hwspinlock_ops,
.probe = stm32mp1_hwspinlock_probe,
.priv_auto_alloc_size = sizeof(struct stm32mp1_hws_priv),
};