xref: /openbmc/linux/arch/arm/mach-imx/src.c (revision 5e012745)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2011 Freescale Semiconductor, Inc.
4  * Copyright 2011 Linaro Ltd.
5  */
6 
7 #include <linux/init.h>
8 #include <linux/io.h>
9 #include <linux/of.h>
10 #include <linux/of_address.h>
11 #include <linux/reset-controller.h>
12 #include <linux/smp.h>
13 #include <asm/smp_plat.h>
14 #include "common.h"
15 
16 #define SRC_SCR				0x000
17 #define SRC_GPR1			0x020
18 #define BP_SRC_SCR_WARM_RESET_ENABLE	0
19 #define BP_SRC_SCR_SW_GPU_RST		1
20 #define BP_SRC_SCR_SW_VPU_RST		2
21 #define BP_SRC_SCR_SW_IPU1_RST		3
22 #define BP_SRC_SCR_SW_OPEN_VG_RST	4
23 #define BP_SRC_SCR_SW_IPU2_RST		12
24 #define BP_SRC_SCR_CORE1_RST		14
25 #define BP_SRC_SCR_CORE1_ENABLE		22
26 
27 static void __iomem *src_base;
28 static DEFINE_SPINLOCK(scr_lock);
29 
30 static const int sw_reset_bits[5] = {
31 	BP_SRC_SCR_SW_GPU_RST,
32 	BP_SRC_SCR_SW_VPU_RST,
33 	BP_SRC_SCR_SW_IPU1_RST,
34 	BP_SRC_SCR_SW_OPEN_VG_RST,
35 	BP_SRC_SCR_SW_IPU2_RST
36 };
37 
38 static int imx_src_reset_module(struct reset_controller_dev *rcdev,
39 		unsigned long sw_reset_idx)
40 {
41 	unsigned long timeout;
42 	unsigned long flags;
43 	int bit;
44 	u32 val;
45 
46 	if (!src_base)
47 		return -ENODEV;
48 
49 	if (sw_reset_idx >= ARRAY_SIZE(sw_reset_bits))
50 		return -EINVAL;
51 
52 	bit = 1 << sw_reset_bits[sw_reset_idx];
53 
54 	spin_lock_irqsave(&scr_lock, flags);
55 	val = readl_relaxed(src_base + SRC_SCR);
56 	val |= bit;
57 	writel_relaxed(val, src_base + SRC_SCR);
58 	spin_unlock_irqrestore(&scr_lock, flags);
59 
60 	timeout = jiffies + msecs_to_jiffies(1000);
61 	while (readl(src_base + SRC_SCR) & bit) {
62 		if (time_after(jiffies, timeout))
63 			return -ETIME;
64 		cpu_relax();
65 	}
66 
67 	return 0;
68 }
69 
70 static const struct reset_control_ops imx_src_ops = {
71 	.reset = imx_src_reset_module,
72 };
73 
74 static struct reset_controller_dev imx_reset_controller = {
75 	.ops = &imx_src_ops,
76 	.nr_resets = ARRAY_SIZE(sw_reset_bits),
77 };
78 
79 void imx_enable_cpu(int cpu, bool enable)
80 {
81 	u32 mask, val;
82 
83 	cpu = cpu_logical_map(cpu);
84 	mask = 1 << (BP_SRC_SCR_CORE1_ENABLE + cpu - 1);
85 	spin_lock(&scr_lock);
86 	val = readl_relaxed(src_base + SRC_SCR);
87 	val = enable ? val | mask : val & ~mask;
88 	val |= 1 << (BP_SRC_SCR_CORE1_RST + cpu - 1);
89 	writel_relaxed(val, src_base + SRC_SCR);
90 	spin_unlock(&scr_lock);
91 }
92 
93 void imx_set_cpu_jump(int cpu, void *jump_addr)
94 {
95 	cpu = cpu_logical_map(cpu);
96 	writel_relaxed(__pa_symbol(jump_addr),
97 		       src_base + SRC_GPR1 + cpu * 8);
98 }
99 
100 u32 imx_get_cpu_arg(int cpu)
101 {
102 	cpu = cpu_logical_map(cpu);
103 	return readl_relaxed(src_base + SRC_GPR1 + cpu * 8 + 4);
104 }
105 
106 void imx_set_cpu_arg(int cpu, u32 arg)
107 {
108 	cpu = cpu_logical_map(cpu);
109 	writel_relaxed(arg, src_base + SRC_GPR1 + cpu * 8 + 4);
110 }
111 
112 void __init imx_src_init(void)
113 {
114 	struct device_node *np;
115 	u32 val;
116 
117 	np = of_find_compatible_node(NULL, NULL, "fsl,imx51-src");
118 	if (!np)
119 		return;
120 	src_base = of_iomap(np, 0);
121 	WARN_ON(!src_base);
122 
123 	imx_reset_controller.of_node = np;
124 	if (IS_ENABLED(CONFIG_RESET_CONTROLLER))
125 		reset_controller_register(&imx_reset_controller);
126 
127 	/*
128 	 * force warm reset sources to generate cold reset
129 	 * for a more reliable restart
130 	 */
131 	spin_lock(&scr_lock);
132 	val = readl_relaxed(src_base + SRC_SCR);
133 	val &= ~(1 << BP_SRC_SCR_WARM_RESET_ENABLE);
134 	writel_relaxed(val, src_base + SRC_SCR);
135 	spin_unlock(&scr_lock);
136 }
137