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
22 static 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
29 static 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
36 static void __iomem *tegra_flowctrl_base;
37
flowctrl_update(u8 offset,u32 value)38 static 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
flowctrl_read_cpu_csr(unsigned int cpuid)51 u32 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
flowctrl_write_cpu_csr(unsigned int cpuid,u32 value)62 void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value)
63 {
64 return flowctrl_update(flowctrl_offset_cpu_csr[cpuid], value);
65 }
66
flowctrl_write_cpu_halt(unsigned int cpuid,u32 value)67 void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value)
68 {
69 return flowctrl_update(flowctrl_offset_halt_cpu[cpuid], value);
70 }
71
flowctrl_cpu_suspend_enter(unsigned int cpuid)72 void 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
flowctrl_cpu_suspend_exit(unsigned int cpuid)128 void 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
tegra_flowctrl_probe(struct platform_device * pdev)156 static int tegra_flowctrl_probe(struct platform_device *pdev)
157 {
158 void __iomem *base = tegra_flowctrl_base;
159 struct resource *res;
160
161 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
162 tegra_flowctrl_base = devm_ioremap_resource(&pdev->dev, res);
163 if (IS_ERR(tegra_flowctrl_base))
164 return PTR_ERR(tegra_flowctrl_base);
165
166 iounmap(base);
167
168 return 0;
169 }
170
171 static const struct of_device_id tegra_flowctrl_match[] = {
172 { .compatible = "nvidia,tegra210-flowctrl" },
173 { .compatible = "nvidia,tegra124-flowctrl" },
174 { .compatible = "nvidia,tegra114-flowctrl" },
175 { .compatible = "nvidia,tegra30-flowctrl" },
176 { .compatible = "nvidia,tegra20-flowctrl" },
177 { }
178 };
179
180 static struct platform_driver tegra_flowctrl_driver = {
181 .driver = {
182 .name = "tegra-flowctrl",
183 .suppress_bind_attrs = true,
184 .of_match_table = tegra_flowctrl_match,
185 },
186 .probe = tegra_flowctrl_probe,
187 };
188 builtin_platform_driver(tegra_flowctrl_driver);
189
tegra_flowctrl_init(void)190 static int __init tegra_flowctrl_init(void)
191 {
192 struct resource res;
193 struct device_node *np;
194
195 if (!soc_is_tegra())
196 return 0;
197
198 np = of_find_matching_node(NULL, tegra_flowctrl_match);
199 if (np) {
200 if (of_address_to_resource(np, 0, &res) < 0) {
201 pr_err("failed to get flowctrl register\n");
202 return -ENXIO;
203 }
204 of_node_put(np);
205 } else if (IS_ENABLED(CONFIG_ARM)) {
206 /*
207 * Hardcoded fallback for 32-bit Tegra
208 * devices if device tree node is missing.
209 */
210 res.start = 0x60007000;
211 res.end = 0x60007fff;
212 res.flags = IORESOURCE_MEM;
213 } else {
214 /*
215 * At this point we're running on a Tegra,
216 * that doesn't support the flow controller
217 * (eg. Tegra186), so just return.
218 */
219 return 0;
220 }
221
222 tegra_flowctrl_base = ioremap(res.start, resource_size(&res));
223 if (!tegra_flowctrl_base)
224 return -ENXIO;
225
226 return 0;
227 }
228 early_initcall(tegra_flowctrl_init);
229