1 // SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
2 /*
3  * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
4  */
5 
6 #include <common.h>
7 #include <clk.h>
8 #include <dm.h>
9 #include <hwspinlock.h>
10 #include <asm/io.h>
11 
12 #define STM32_MUTEX_COREID	BIT(8)
13 #define STM32_MUTEX_LOCK_BIT	BIT(31)
14 #define STM32_MUTEX_NUM_LOCKS	32
15 
16 struct stm32mp1_hws_priv {
17 	fdt_addr_t base;
18 };
19 
stm32mp1_lock(struct udevice * dev,int index)20 static int stm32mp1_lock(struct udevice *dev, int index)
21 {
22 	struct stm32mp1_hws_priv *priv = dev_get_priv(dev);
23 	u32 status;
24 
25 	if (index >= STM32_MUTEX_NUM_LOCKS)
26 		return -EINVAL;
27 
28 	status = readl(priv->base + index * sizeof(u32));
29 	if (status == (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID))
30 		return -EBUSY;
31 
32 	writel(STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID,
33 	       priv->base + index * sizeof(u32));
34 
35 	status = readl(priv->base + index * sizeof(u32));
36 	if (status != (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID))
37 		return -EINVAL;
38 
39 	return 0;
40 }
41 
stm32mp1_unlock(struct udevice * dev,int index)42 static int stm32mp1_unlock(struct udevice *dev, int index)
43 {
44 	struct stm32mp1_hws_priv *priv = dev_get_priv(dev);
45 
46 	if (index >= STM32_MUTEX_NUM_LOCKS)
47 		return -EINVAL;
48 
49 	writel(STM32_MUTEX_COREID, priv->base + index * sizeof(u32));
50 
51 	return 0;
52 }
53 
stm32mp1_hwspinlock_probe(struct udevice * dev)54 static int stm32mp1_hwspinlock_probe(struct udevice *dev)
55 {
56 	struct stm32mp1_hws_priv *priv = dev_get_priv(dev);
57 	struct clk clk;
58 	int ret;
59 
60 	priv->base = dev_read_addr(dev);
61 	if (priv->base == FDT_ADDR_T_NONE)
62 		return -EINVAL;
63 
64 	ret = clk_get_by_index(dev, 0, &clk);
65 	if (ret)
66 		return ret;
67 
68 	ret = clk_enable(&clk);
69 	if (ret)
70 		clk_free(&clk);
71 
72 	return ret;
73 }
74 
75 static const struct hwspinlock_ops stm32mp1_hwspinlock_ops = {
76 	.lock = stm32mp1_lock,
77 	.unlock = stm32mp1_unlock,
78 };
79 
80 static const struct udevice_id stm32mp1_hwspinlock_ids[] = {
81 	{ .compatible = "st,stm32-hwspinlock" },
82 	{}
83 };
84 
85 U_BOOT_DRIVER(hwspinlock_stm32mp1) = {
86 	.name = "hwspinlock_stm32mp1",
87 	.id = UCLASS_HWSPINLOCK,
88 	.of_match = stm32mp1_hwspinlock_ids,
89 	.ops = &stm32mp1_hwspinlock_ops,
90 	.probe = stm32mp1_hwspinlock_probe,
91 	.priv_auto_alloc_size = sizeof(struct stm32mp1_hws_priv),
92 };
93