1 // SPDX-License-Identifier: GPL-2.0-only
3 * drivers/soc/tegra/flowctrl.c
5 * Functions and macros to control the flowcontroller
7 * Copyright (c) 2010-2012, NVIDIA Corporation. All rights reserved.
10 #include <linux/cpumask.h>
11 #include <linux/init.h>
13 #include <linux/kernel.h>
15 #include <linux/of_address.h>
16 #include <linux/platform_device.h>
18 #include <soc/tegra/common.h>
19 #include <soc/tegra/flowctrl.h>
20 #include <soc/tegra/fuse.h>
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,
29 static u8 flowctrl_offset_cpu_csr[] = {
32 FLOW_CTRL_CPU1_CSR + 8,
33 FLOW_CTRL_CPU1_CSR + 16,
36 static void __iomem *tegra_flowctrl_base;
38 static void flowctrl_update(u8 offset, u32 value)
40 if (WARN_ONCE(IS_ERR_OR_NULL(tegra_flowctrl_base),
41 "Tegra flowctrl not initialised!\n"))
44 writel(value, tegra_flowctrl_base + offset);
46 /* ensure the update has reached the flow controller */
48 readl_relaxed(tegra_flowctrl_base + offset);
51 u32 flowctrl_read_cpu_csr(unsigned int cpuid)
53 u8 offset = flowctrl_offset_cpu_csr[cpuid];
55 if (WARN_ONCE(IS_ERR_OR_NULL(tegra_flowctrl_base),
56 "Tegra flowctrl not initialised!\n"))
59 return readl(tegra_flowctrl_base + offset);
62 void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value)
64 return flowctrl_update(flowctrl_offset_cpu_csr[cpuid], value);
67 void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value)
69 return flowctrl_update(flowctrl_offset_halt_cpu[cpuid], value);
72 void flowctrl_cpu_suspend_enter(unsigned int cpuid)
77 reg = flowctrl_read_cpu_csr(cpuid);
78 switch (tegra_get_chip_id()) {
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;
90 /* clear wfe bitmap */
91 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
92 /* clear wfi bitmap */
93 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
95 if (tegra_get_chip_id() == TEGRA30) {
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.
106 reg |= TEGRA20_FLOW_CTRL_CSR_WFE_CPU0 << cpuid;
108 /* pwr gating on wfi */
109 reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
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);
118 for (i = 0; i < num_possible_cpus(); i++) {
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);
128 void flowctrl_cpu_suspend_exit(unsigned int cpuid)
132 /* Disable powergating via flow controller for CPU0 */
133 reg = flowctrl_read_cpu_csr(cpuid);
134 switch (tegra_get_chip_id()) {
136 /* clear wfe bitmap */
137 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
138 /* clear wfi bitmap */
139 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
144 /* clear wfe bitmap */
145 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
146 /* clear wfi bitmap */
147 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
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);
156 static int tegra_flowctrl_probe(struct platform_device *pdev)
158 void __iomem *base = tegra_flowctrl_base;
159 struct resource *res;
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);
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" },
180 static struct platform_driver tegra_flowctrl_driver = {
182 .name = "tegra-flowctrl",
183 .suppress_bind_attrs = true,
184 .of_match_table = tegra_flowctrl_match,
186 .probe = tegra_flowctrl_probe,
188 builtin_platform_driver(tegra_flowctrl_driver);
190 static int __init tegra_flowctrl_init(void)
193 struct device_node *np;
198 np = of_find_matching_node(NULL, tegra_flowctrl_match);
200 if (of_address_to_resource(np, 0, &res) < 0) {
201 pr_err("failed to get flowctrl register\n");
205 } else if (IS_ENABLED(CONFIG_ARM)) {
207 * Hardcoded fallback for 32-bit Tegra
208 * devices if device tree node is missing.
210 res.start = 0x60007000;
211 res.end = 0x60007fff;
212 res.flags = IORESOURCE_MEM;
215 * At this point we're running on a Tegra,
216 * that doesn't support the flow controller
217 * (eg. Tegra186), so just return.
222 tegra_flowctrl_base = ioremap(res.start, resource_size(&res));
223 if (!tegra_flowctrl_base)
228 early_initcall(tegra_flowctrl_init);