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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/soc/tegra/flowctrl.c
4 *
5 * Functions and macros to control the flowcontroller
6 *
7 * Copyright (c) 2010-2012, NVIDIA Corporation. All rights reserved.
8 */
9
10#include <linux/cpumask.h>
11#include <linux/init.h>
12#include <linux/io.h>
13#include <linux/kernel.h>
14#include <linux/of.h>
15#include <linux/of_address.h>
16#include <linux/platform_device.h>
17
18#include <soc/tegra/common.h>
19#include <soc/tegra/flowctrl.h>
20#include <soc/tegra/fuse.h>
21
22static u8 flowctrl_offset_halt_cpu[] = {
23 FLOW_CTRL_HALT_CPU0_EVENTS,
24 FLOW_CTRL_HALT_CPU1_EVENTS,
25 FLOW_CTRL_HALT_CPU1_EVENTS + 8,
26 FLOW_CTRL_HALT_CPU1_EVENTS + 16,
27};
28
29static u8 flowctrl_offset_cpu_csr[] = {
30 FLOW_CTRL_CPU0_CSR,
31 FLOW_CTRL_CPU1_CSR,
32 FLOW_CTRL_CPU1_CSR + 8,
33 FLOW_CTRL_CPU1_CSR + 16,
34};
35
36static void __iomem *tegra_flowctrl_base;
37
38static void flowctrl_update(u8 offset, u32 value)
39{
40 if (WARN_ONCE(IS_ERR_OR_NULL(tegra_flowctrl_base),
41 "Tegra flowctrl not initialised!\n"))
42 return;
43
44 writel(value, tegra_flowctrl_base + offset);
45
46 /* ensure the update has reached the flow controller */
47 wmb();
48 readl_relaxed(tegra_flowctrl_base + offset);
49}
50
51u32 flowctrl_read_cpu_csr(unsigned int cpuid)
52{
53 u8 offset = flowctrl_offset_cpu_csr[cpuid];
54
55 if (WARN_ONCE(IS_ERR_OR_NULL(tegra_flowctrl_base),
56 "Tegra flowctrl not initialised!\n"))
57 return 0;
58
59 return readl(tegra_flowctrl_base + offset);
60}
61
62void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value)
63{
64 return flowctrl_update(flowctrl_offset_cpu_csr[cpuid], value);
65}
66
67void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value)
68{
69 return flowctrl_update(flowctrl_offset_halt_cpu[cpuid], value);
70}
71
72void flowctrl_cpu_suspend_enter(unsigned int cpuid)
73{
74 unsigned int reg;
75 int i;
76
77 reg = flowctrl_read_cpu_csr(cpuid);
78 switch (tegra_get_chip_id()) {
79 case TEGRA20:
80 /* clear wfe bitmap */
81 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
82 /* clear wfi bitmap */
83 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
84 /* pwr gating on wfe */
85 reg |= TEGRA20_FLOW_CTRL_CSR_WFE_CPU0 << cpuid;
86 break;
87 case TEGRA30:
88 case TEGRA114:
89 case TEGRA124:
90 /* clear wfe bitmap */
91 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
92 /* clear wfi bitmap */
93 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
94
95 if (tegra_get_chip_id() == TEGRA30) {
96 /*
97 * The wfi doesn't work well on Tegra30 because
98 * CPU hangs under some odd circumstances after
99 * power-gating (like memory running off PLLP),
100 * hence use wfe that is working perfectly fine.
101 * Note that Tegra30 TRM doc clearly stands that
102 * wfi should be used for the "Cluster Switching",
103 * while wfe for the power-gating, just like it
104 * is done on Tegra20.
105 */
106 reg |= TEGRA20_FLOW_CTRL_CSR_WFE_CPU0 << cpuid;
107 } else {
108 /* pwr gating on wfi */
109 reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
110 }
111 break;
112 }
113 reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr flag */
114 reg |= FLOW_CTRL_CSR_EVENT_FLAG; /* clear event flag */
115 reg |= FLOW_CTRL_CSR_ENABLE; /* pwr gating */
116 flowctrl_write_cpu_csr(cpuid, reg);
117
118 for (i = 0; i < num_possible_cpus(); i++) {
119 if (i == cpuid)
120 continue;
121 reg = flowctrl_read_cpu_csr(i);
122 reg |= FLOW_CTRL_CSR_EVENT_FLAG;
123 reg |= FLOW_CTRL_CSR_INTR_FLAG;
124 flowctrl_write_cpu_csr(i, reg);
125 }
126}
127
128void flowctrl_cpu_suspend_exit(unsigned int cpuid)
129{
130 unsigned int reg;
131
132 /* Disable powergating via flow controller for CPU0 */
133 reg = flowctrl_read_cpu_csr(cpuid);
134 switch (tegra_get_chip_id()) {
135 case TEGRA20:
136 /* clear wfe bitmap */
137 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
138 /* clear wfi bitmap */
139 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
140 break;
141 case TEGRA30:
142 case TEGRA114:
143 case TEGRA124:
144 /* clear wfe bitmap */
145 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
146 /* clear wfi bitmap */
147 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
148 break;
149 }
150 reg &= ~FLOW_CTRL_CSR_ENABLE; /* clear enable */
151 reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr */
152 reg |= FLOW_CTRL_CSR_EVENT_FLAG; /* clear event */
153 flowctrl_write_cpu_csr(cpuid, reg);
154}
155
156static int tegra_flowctrl_probe(struct platform_device *pdev)
157{
158 void __iomem *base = tegra_flowctrl_base;
159
160 tegra_flowctrl_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
161 if (IS_ERR(tegra_flowctrl_base))
162 return PTR_ERR(tegra_flowctrl_base);
163
164 iounmap(base);
165
166 return 0;
167}
168
169static const struct of_device_id tegra_flowctrl_match[] = {
170 { .compatible = "nvidia,tegra210-flowctrl" },
171 { .compatible = "nvidia,tegra124-flowctrl" },
172 { .compatible = "nvidia,tegra114-flowctrl" },
173 { .compatible = "nvidia,tegra30-flowctrl" },
174 { .compatible = "nvidia,tegra20-flowctrl" },
175 { }
176};
177
178static struct platform_driver tegra_flowctrl_driver = {
179 .driver = {
180 .name = "tegra-flowctrl",
181 .suppress_bind_attrs = true,
182 .of_match_table = tegra_flowctrl_match,
183 },
184 .probe = tegra_flowctrl_probe,
185};
186builtin_platform_driver(tegra_flowctrl_driver);
187
188static int __init tegra_flowctrl_init(void)
189{
190 struct resource res;
191 struct device_node *np;
192
193 if (!soc_is_tegra())
194 return 0;
195
196 np = of_find_matching_node(NULL, tegra_flowctrl_match);
197 if (np) {
198 if (of_address_to_resource(np, 0, &res) < 0) {
199 pr_err("failed to get flowctrl register\n");
200 return -ENXIO;
201 }
202 of_node_put(np);
203 } else if (IS_ENABLED(CONFIG_ARM)) {
204 /*
205 * Hardcoded fallback for 32-bit Tegra
206 * devices if device tree node is missing.
207 */
208 res.start = 0x60007000;
209 res.end = 0x60007fff;
210 res.flags = IORESOURCE_MEM;
211 } else {
212 /*
213 * At this point we're running on a Tegra,
214 * that doesn't support the flow controller
215 * (eg. Tegra186), so just return.
216 */
217 return 0;
218 }
219
220 tegra_flowctrl_base = ioremap(res.start, resource_size(&res));
221 if (!tegra_flowctrl_base)
222 return -ENXIO;
223
224 return 0;
225}
226early_initcall(tegra_flowctrl_init);