xref: /openbmc/linux/arch/arm/mach-imx/src.c (revision a1467faa)
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/iopoll.h>
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12 #include <linux/platform_device.h>
13 #include <linux/reset-controller.h>
14 #include <linux/smp.h>
15 #include <asm/smp_plat.h>
16 #include "common.h"
17 #include "hardware.h"
18 
19 #define SRC_SCR				0x000
20 #define SRC_GPR1_V1			0x020
21 #define SRC_GPR1_V2			0x074
22 #define SRC_GPR1(gpr_v2)		((gpr_v2) ? SRC_GPR1_V2 : SRC_GPR1_V1)
23 #define BP_SRC_SCR_WARM_RESET_ENABLE	0
24 #define BP_SRC_SCR_SW_GPU_RST		1
25 #define BP_SRC_SCR_SW_VPU_RST		2
26 #define BP_SRC_SCR_SW_IPU1_RST		3
27 #define BP_SRC_SCR_SW_OPEN_VG_RST	4
28 #define BP_SRC_SCR_SW_IPU2_RST		12
29 #define BP_SRC_SCR_CORE1_RST		14
30 #define BP_SRC_SCR_CORE1_ENABLE		22
31 /* below is for i.MX7D */
32 #define SRC_A7RCR1			0x008
33 #define BP_SRC_A7RCR1_A7_CORE1_ENABLE	1
34 #define GPC_CPU_PGC_SW_PUP_REQ		0xf0
35 #define GPC_CPU_PGC_SW_PDN_REQ		0xfc
36 #define GPC_PGC_C1			0x840
37 #define BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7	0x2
38 
39 static void __iomem *src_base;
40 static DEFINE_SPINLOCK(scr_lock);
41 static bool gpr_v2;
42 static void __iomem *gpc_base;
43 
44 static const int sw_reset_bits[5] = {
45 	BP_SRC_SCR_SW_GPU_RST,
46 	BP_SRC_SCR_SW_VPU_RST,
47 	BP_SRC_SCR_SW_IPU1_RST,
48 	BP_SRC_SCR_SW_OPEN_VG_RST,
49 	BP_SRC_SCR_SW_IPU2_RST
50 };
51 
imx_src_reset_module(struct reset_controller_dev * rcdev,unsigned long sw_reset_idx)52 static int imx_src_reset_module(struct reset_controller_dev *rcdev,
53 		unsigned long sw_reset_idx)
54 {
55 	unsigned long timeout;
56 	unsigned long flags;
57 	int bit;
58 	u32 val;
59 
60 	if (sw_reset_idx >= ARRAY_SIZE(sw_reset_bits))
61 		return -EINVAL;
62 
63 	bit = 1 << sw_reset_bits[sw_reset_idx];
64 
65 	spin_lock_irqsave(&scr_lock, flags);
66 	val = readl_relaxed(src_base + SRC_SCR);
67 	val |= bit;
68 	writel_relaxed(val, src_base + SRC_SCR);
69 	spin_unlock_irqrestore(&scr_lock, flags);
70 
71 	timeout = jiffies + msecs_to_jiffies(1000);
72 	while (readl(src_base + SRC_SCR) & bit) {
73 		if (time_after(jiffies, timeout))
74 			return -ETIME;
75 		cpu_relax();
76 	}
77 
78 	return 0;
79 }
80 
81 static const struct reset_control_ops imx_src_ops = {
82 	.reset = imx_src_reset_module,
83 };
84 
imx_gpcv2_set_m_core_pgc(bool enable,u32 offset)85 static void imx_gpcv2_set_m_core_pgc(bool enable, u32 offset)
86 {
87 	writel_relaxed(enable, gpc_base + offset);
88 }
89 
90 /*
91  * The motivation for bringing up the second i.MX7D core inside the kernel
92  * is that legacy vendor bootloaders usually do not implement PSCI support.
93  * This is a significant blocker for systems in the field that are running old
94  * bootloader versions to upgrade to a modern mainline kernel version, as only
95  * one CPU of the i.MX7D would be brought up.
96  * Bring up the second i.MX7D core inside the kernel to make the migration
97  * path to mainline kernel easier for the existing iMX7D users.
98  */
imx_gpcv2_set_core1_pdn_pup_by_software(bool pdn)99 void imx_gpcv2_set_core1_pdn_pup_by_software(bool pdn)
100 {
101 	u32 reg = pdn ? GPC_CPU_PGC_SW_PDN_REQ : GPC_CPU_PGC_SW_PUP_REQ;
102 	u32 val, pup;
103 	int ret;
104 
105 	imx_gpcv2_set_m_core_pgc(true, GPC_PGC_C1);
106 	val = readl_relaxed(gpc_base + reg);
107 	val |= BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7;
108 	writel_relaxed(val, gpc_base + reg);
109 
110 	ret = readl_relaxed_poll_timeout_atomic(gpc_base + reg, pup,
111 				!(pup & BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7),
112 				5, 1000000);
113 	if (ret < 0) {
114 		pr_err("i.MX7D: CORE1_A7 power up timeout\n");
115 		val &= ~BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7;
116 		writel_relaxed(val, gpc_base + reg);
117 	}
118 
119 	imx_gpcv2_set_m_core_pgc(false, GPC_PGC_C1);
120 }
121 
imx_enable_cpu(int cpu,bool enable)122 void imx_enable_cpu(int cpu, bool enable)
123 {
124 	u32 mask, val;
125 
126 	cpu = cpu_logical_map(cpu);
127 	spin_lock(&scr_lock);
128 	if (gpr_v2) {
129 		if (enable)
130 			imx_gpcv2_set_core1_pdn_pup_by_software(false);
131 
132 		mask = 1 << (BP_SRC_A7RCR1_A7_CORE1_ENABLE + cpu - 1);
133 		val = readl_relaxed(src_base + SRC_A7RCR1);
134 		val = enable ? val | mask : val & ~mask;
135 		writel_relaxed(val, src_base + SRC_A7RCR1);
136 	} else {
137 		mask = 1 << (BP_SRC_SCR_CORE1_ENABLE + cpu - 1);
138 		val = readl_relaxed(src_base + SRC_SCR);
139 		val = enable ? val | mask : val & ~mask;
140 		val |= 1 << (BP_SRC_SCR_CORE1_RST + cpu - 1);
141 		writel_relaxed(val, src_base + SRC_SCR);
142 	}
143 	spin_unlock(&scr_lock);
144 }
145 
imx_set_cpu_jump(int cpu,void * jump_addr)146 void imx_set_cpu_jump(int cpu, void *jump_addr)
147 {
148 	cpu = cpu_logical_map(cpu);
149 	writel_relaxed(__pa_symbol(jump_addr),
150 		       src_base + SRC_GPR1(gpr_v2) + cpu * 8);
151 }
152 
imx_get_cpu_arg(int cpu)153 u32 imx_get_cpu_arg(int cpu)
154 {
155 	cpu = cpu_logical_map(cpu);
156 	return readl_relaxed(src_base + SRC_GPR1(gpr_v2) + cpu * 8 + 4);
157 }
158 
imx_set_cpu_arg(int cpu,u32 arg)159 void imx_set_cpu_arg(int cpu, u32 arg)
160 {
161 	cpu = cpu_logical_map(cpu);
162 	writel_relaxed(arg, src_base + SRC_GPR1(gpr_v2) + cpu * 8 + 4);
163 }
164 
imx_src_init(void)165 void __init imx_src_init(void)
166 {
167 	struct device_node *np;
168 	u32 val;
169 
170 	np = of_find_compatible_node(NULL, NULL, "fsl,imx51-src");
171 	if (!np)
172 		return;
173 	src_base = of_iomap(np, 0);
174 	WARN_ON(!src_base);
175 
176 	/*
177 	 * force warm reset sources to generate cold reset
178 	 * for a more reliable restart
179 	 */
180 	spin_lock(&scr_lock);
181 	val = readl_relaxed(src_base + SRC_SCR);
182 	val &= ~(1 << BP_SRC_SCR_WARM_RESET_ENABLE);
183 	writel_relaxed(val, src_base + SRC_SCR);
184 	spin_unlock(&scr_lock);
185 }
186 
imx7_src_init(void)187 void __init imx7_src_init(void)
188 {
189 	struct device_node *np;
190 
191 	gpr_v2 = true;
192 
193 	np = of_find_compatible_node(NULL, NULL, "fsl,imx7d-src");
194 	if (!np)
195 		return;
196 
197 	src_base = of_iomap(np, 0);
198 	if (!src_base)
199 		return;
200 
201 	np = of_find_compatible_node(NULL, NULL, "fsl,imx7d-gpc");
202 	if (!np)
203 		return;
204 
205 	gpc_base = of_iomap(np, 0);
206 	if (!gpc_base)
207 		return;
208 }
209 
210 static const struct of_device_id imx_src_dt_ids[] = {
211 	{ .compatible = "fsl,imx51-src" },
212 	{ /* sentinel */ }
213 };
214 
imx_src_probe(struct platform_device * pdev)215 static int imx_src_probe(struct platform_device *pdev)
216 {
217 	struct reset_controller_dev *rcdev;
218 
219 	rcdev = devm_kzalloc(&pdev->dev, sizeof(*rcdev), GFP_KERNEL);
220 	if (!rcdev)
221 		return -ENOMEM;
222 
223 	rcdev->ops = &imx_src_ops;
224 	rcdev->dev = &pdev->dev;
225 	rcdev->of_node = pdev->dev.of_node;
226 	rcdev->nr_resets = ARRAY_SIZE(sw_reset_bits);
227 
228 	return devm_reset_controller_register(&pdev->dev, rcdev);
229 }
230 
231 static struct platform_driver imx_src_driver = {
232 	.driver = {
233 		.name = "imx-src",
234 		.of_match_table = imx_src_dt_ids,
235 	},
236 	.probe = imx_src_probe,
237 };
238 builtin_platform_driver(imx_src_driver);
239