diff options
Diffstat (limited to 'drivers/soc/tegra/flowctrl.c')
| -rw-r--r-- | drivers/soc/tegra/flowctrl.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/drivers/soc/tegra/flowctrl.c b/drivers/soc/tegra/flowctrl.c new file mode 100644 index 000000000..5db919d96 --- /dev/null +++ b/drivers/soc/tegra/flowctrl.c @@ -0,0 +1,228 @@ +// 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; + struct resource *res; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + tegra_flowctrl_base = devm_ioremap_resource(&pdev->dev, res); + 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); |