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 /* pwr gating on wfi */
95 reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
96 break;
97 }
98 reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr flag */
99 reg |= FLOW_CTRL_CSR_EVENT_FLAG; /* clear event flag */
100 reg |= FLOW_CTRL_CSR_ENABLE; /* pwr gating */
101 flowctrl_write_cpu_csr(cpuid, reg);
102
103 for (i = 0; i < num_possible_cpus(); i++) {
104 if (i == cpuid)
105 continue;
106 reg = flowctrl_read_cpu_csr(i);
107 reg |= FLOW_CTRL_CSR_EVENT_FLAG;
108 reg |= FLOW_CTRL_CSR_INTR_FLAG;
109 flowctrl_write_cpu_csr(i, reg);
110 }
111 }
112
flowctrl_cpu_suspend_exit(unsigned int cpuid)113 void flowctrl_cpu_suspend_exit(unsigned int cpuid)
114 {
115 unsigned int reg;
116
117 /* Disable powergating via flow controller for CPU0 */
118 reg = flowctrl_read_cpu_csr(cpuid);
119 switch (tegra_get_chip_id()) {
120 case TEGRA20:
121 /* clear wfe bitmap */
122 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
123 /* clear wfi bitmap */
124 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
125 break;
126 case TEGRA30:
127 case TEGRA114:
128 case TEGRA124:
129 /* clear wfe bitmap */
130 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
131 /* clear wfi bitmap */
132 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
133 break;
134 }
135 reg &= ~FLOW_CTRL_CSR_ENABLE; /* clear enable */
136 reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr */
137 reg |= FLOW_CTRL_CSR_EVENT_FLAG; /* clear event */
138 flowctrl_write_cpu_csr(cpuid, reg);
139 }
140
tegra_flowctrl_probe(struct platform_device * pdev)141 static int tegra_flowctrl_probe(struct platform_device *pdev)
142 {
143 void __iomem *base = tegra_flowctrl_base;
144 struct resource *res;
145
146 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
147 tegra_flowctrl_base = devm_ioremap_resource(&pdev->dev, res);
148 if (IS_ERR(tegra_flowctrl_base))
149 return PTR_ERR(tegra_flowctrl_base);
150
151 iounmap(base);
152
153 return 0;
154 }
155
156 static const struct of_device_id tegra_flowctrl_match[] = {
157 { .compatible = "nvidia,tegra210-flowctrl" },
158 { .compatible = "nvidia,tegra124-flowctrl" },
159 { .compatible = "nvidia,tegra114-flowctrl" },
160 { .compatible = "nvidia,tegra30-flowctrl" },
161 { .compatible = "nvidia,tegra20-flowctrl" },
162 { }
163 };
164
165 static struct platform_driver tegra_flowctrl_driver = {
166 .driver = {
167 .name = "tegra-flowctrl",
168 .suppress_bind_attrs = true,
169 .of_match_table = tegra_flowctrl_match,
170 },
171 .probe = tegra_flowctrl_probe,
172 };
173 builtin_platform_driver(tegra_flowctrl_driver);
174
tegra_flowctrl_init(void)175 static int __init tegra_flowctrl_init(void)
176 {
177 struct resource res;
178 struct device_node *np;
179
180 if (!soc_is_tegra())
181 return 0;
182
183 np = of_find_matching_node(NULL, tegra_flowctrl_match);
184 if (np) {
185 if (of_address_to_resource(np, 0, &res) < 0) {
186 pr_err("failed to get flowctrl register\n");
187 return -ENXIO;
188 }
189 of_node_put(np);
190 } else if (IS_ENABLED(CONFIG_ARM)) {
191 /*
192 * Hardcoded fallback for 32-bit Tegra
193 * devices if device tree node is missing.
194 */
195 res.start = 0x60007000;
196 res.end = 0x60007fff;
197 res.flags = IORESOURCE_MEM;
198 } else {
199 /*
200 * At this point we're running on a Tegra,
201 * that doesn't support the flow controller
202 * (eg. Tegra186), so just return.
203 */
204 return 0;
205 }
206
207 tegra_flowctrl_base = ioremap_nocache(res.start, resource_size(&res));
208 if (!tegra_flowctrl_base)
209 return -ENXIO;
210
211 return 0;
212 }
213 early_initcall(tegra_flowctrl_init);
214
