// SPDX-License-Identifier: GPL-2.0-only
/*
* drivers/soc/tegra/flowctrl.c
*
* Functions and macros to control the flowcontroller
*
* Copyright (c) 2010-2012, NVIDIA Corporation. All rights reserved.
*/
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <soc/tegra/common.h>
#include <soc/tegra/flowctrl.h>
#include <soc/tegra/fuse.h>
static u8 flowctrl_offset_halt_cpu[] = {
FLOW_CTRL_HALT_CPU0_EVENTS,
FLOW_CTRL_HALT_CPU1_EVENTS,
FLOW_CTRL_HALT_CPU1_EVENTS + 8,
FLOW_CTRL_HALT_CPU1_EVENTS + 16,
};
static u8 flowctrl_offset_cpu_csr[] = {
FLOW_CTRL_CPU0_CSR,
FLOW_CTRL_CPU1_CSR,
FLOW_CTRL_CPU1_CSR + 8,
FLOW_CTRL_CPU1_CSR + 16,
};
static void __iomem *tegra_flowctrl_base;
static void flowctrl_update(u8 offset, u32 value)
{
if (WARN_ONCE(IS_ERR_OR_NULL(tegra_flowctrl_base),
"Tegra flowctrl not initialised!\n"))
return;
writel(value, tegra_flowctrl_base + offset);
/* ensure the update has reached the flow controller */
wmb();
readl_relaxed(tegra_flowctrl_base + offset);
}
u32 flowctrl_read_cpu_csr(unsigned int cpuid)
{
u8 offset = flowctrl_offset_cpu_csr[cpuid];
if (WARN_ONCE(IS_ERR_OR_NULL(tegra_flowctrl_base),
"Tegra flowctrl not initialised!\n"))
return 0;
return readl(tegra_flowctrl_base + offset);
}
void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value)
{
return flowctrl_update(flowctrl_offset_cpu_csr[cpuid], value);
}
void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value)
{
return flowctrl_update(flowctrl_offset_halt_cpu[cpuid], value);
}
void flowctrl_cpu_suspend_enter(unsigned int cpuid)
{
unsigned int reg;
int i;
reg = flowctrl_read_cpu_csr(cpuid);
switch (tegra_get_chip_id()) {
case TEGRA20:
/* clear wfe bitmap */
reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
/* clear wfi bitmap */
reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
/* pwr gating on wfe */
reg |= TEGRA20_FLOW_CTRL_CSR_WFE_CPU0 << cpuid;
break;
case TEGRA30:
case TEGRA114:
case TEGRA124:
/* clear wfe bitmap */
reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
/* clear wfi bitmap */
reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
if (tegra_get_chip_id() == TEGRA30) {
/*
* The wfi doesn't work well on Tegra30 because
* CPU hangs under some odd circumstances after
* power-gating (like memory running off PLLP),
* hence use wfe that is working perfectly fine.
* Note that Tegra30 TRM doc clearly stands that
* wfi should be used for the "Cluster Switching",
* while wfe for the power-gating, just like it
* is done on Tegra20.
*/
reg |= TEGRA20_FLOW_CTRL_CSR_WFE_CPU0 << cpuid;
} else {
/* pwr gating on wfi */
reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
}
break;
}
reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr flag */
reg |= FLOW_CTRL_CSR_EVENT_FLAG; /* clear event flag */
reg |= FLOW_CTRL_CSR_ENABLE; /* pwr gating */
flowctrl_write_cpu_csr(cpuid, reg);
for (i = 0; i < num_possible_cpus(); i++) {
if (i == cpuid)
continue;
reg = flowctrl_read_cpu_csr(i);
reg |= FLOW_CTRL_CSR_EVENT_FLAG;
reg |= FLOW_CTRL_CSR_INTR_FLAG;
flowctrl_write_cpu_csr(i, reg);
}
}
void flowctrl_cpu_suspend_exit(unsigned int cpuid)
{
unsigned int reg;
/* Disable powergating via flow controller for CPU0 */
reg = flowctrl_read_cpu_csr(cpuid);
switch (tegra_get_chip_id()) {
case TEGRA20:
/* clear wfe bitmap */
reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
/* clear wfi bitmap */
reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
break;
case TEGRA30:
case TEGRA114:
case TEGRA124:
/* clear wfe bitmap */
reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
/* clear wfi bitmap */
reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
break;
}
reg &= ~FLOW_CTRL_CSR_ENABLE; /* clear enable */
reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr */
reg |= FLOW_CTRL_CSR_EVENT_FLAG; /* clear event */
flowctrl_write_cpu_csr(cpuid, reg);
}
static int tegra_flowctrl_probe(struct platform_device *pdev)
{
void __iomem *base = tegra_flowctrl_base;
tegra_flowctrl_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
if (IS_ERR(tegra_flowctrl_base))
return PTR_ERR(tegra_flowctrl_base);
iounmap(base);
return 0;
}
static const struct of_device_id tegra_flowctrl_match[] = {
{ .compatible = "nvidia,tegra210-flowctrl" },
{ .compatible = "nvidia,tegra124-flowctrl" },
{ .compatible = "nvidia,tegra114-flowctrl" },
{ .compatible = "nvidia,tegra30-flowctrl" },
{ .compatible = "nvidia,tegra20-flowctrl" },
{ }
};
static struct platform_driver tegra_flowctrl_driver = {
.driver = {
.name = "tegra-flowctrl",
.suppress_bind_attrs = true,
.of_match_table = tegra_flowctrl_match,
},
.probe = tegra_flowctrl_probe,
};
builtin_platform_driver(tegra_flowctrl_driver);
static int __init tegra_flowctrl_init(void)
{
struct resource res;
struct device_node *np;
if (!soc_is_tegra())
return 0;
np = of_find_matching_node(NULL, tegra_flowctrl_match);
if (np) {
if (of_address_to_resource(np, 0, &res) < 0) {
pr_err("failed to get flowctrl register\n");
return -ENXIO;
}
of_node_put(np);
} else if (IS_ENABLED(CONFIG_ARM)) {
/*
* Hardcoded fallback for 32-bit Tegra
* devices if device tree node is missing.
*/
res.start = 0x60007000;
res.end = 0x60007fff;
res.flags = IORESOURCE_MEM;
} else {
/*
* At this point we're running on a Tegra,
* that doesn't support the flow controller
* (eg. Tegra186), so just return.
*/
return 0;
}
tegra_flowctrl_base = ioremap(res.start, resource_size(&res));
if (!tegra_flowctrl_base)
return -ENXIO;
return 0;
}
early_initcall(tegra_flowctrl_init);
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