From: "Hector.Yuan" <hector.yuan@xxxxxxxxxxxx> Add cpufreq HW support. Signed-off-by: Hector.Yuan <hector.yuan@xxxxxxxxxxxx> --- drivers/cpufreq/Kconfig.arm | 12 ++ drivers/cpufreq/Makefile | 1 + drivers/cpufreq/mediatek-cpufreq-hw.c | 370 +++++++++++++++++++++++++++++++++ 3 files changed, 383 insertions(+) create mode 100644 drivers/cpufreq/mediatek-cpufreq-hw.c diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index e65e0a4..1b950a8 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -123,6 +123,18 @@ config ARM_MEDIATEK_CPUFREQ help This adds the CPUFreq driver support for MediaTek SoCs. +config ARM_MEDIATEK_CPUFREQ_HW + tristate "MediaTek CPUFreq HW driver" + depends on ARCH_MEDIATEK || COMPILE_TEST + default m + help + Support for the CPUFreq HW driver. + Some MediaTek chipsets have a HW engine to offload the steps + necessary for changing the frequency of the CPUs. Firmware loaded + in this engine exposes a programming interface to the OS. + The driver implements the cpufreq interface for this HW engine. + Say Y if you want to support CPUFreq HW. + config ARM_OMAP2PLUS_CPUFREQ bool "TI OMAP2+" depends on ARCH_OMAP2PLUS diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index 27d3bd7..48ee585 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -56,6 +56,7 @@ obj-$(CONFIG_ARM_IMX6Q_CPUFREQ) += imx6q-cpufreq.o obj-$(CONFIG_ARM_IMX_CPUFREQ_DT) += imx-cpufreq-dt.o obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ) += kirkwood-cpufreq.o obj-$(CONFIG_ARM_MEDIATEK_CPUFREQ) += mediatek-cpufreq.o +obj-$(CONFIG_ARM_MEDIATEK_CPUFREQ_HW) += mediatek-cpufreq-hw.o obj-$(CONFIG_MACH_MVEBU_V7) += mvebu-cpufreq.o obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o obj-$(CONFIG_ARM_PXA2xx_CPUFREQ) += pxa2xx-cpufreq.o diff --git a/drivers/cpufreq/mediatek-cpufreq-hw.c b/drivers/cpufreq/mediatek-cpufreq-hw.c new file mode 100644 index 0000000..6f3a461 --- /dev/null +++ b/drivers/cpufreq/mediatek-cpufreq-hw.c @@ -0,0 +1,370 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2020 MediaTek Inc. + */ + +#include <linux/bitfield.h> +#include <linux/cpufreq.h> +#include <linux/energy_model.h> +#include <linux/init.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/pm_qos.h> +#include <linux/slab.h> + +#define LUT_MAX_ENTRIES 32U +#define LUT_FREQ GENMASK(11, 0) +#define LUT_ROW_SIZE 0x4 +#define CPUFREQ_HW_STATUS BIT(0) +#define SVS_HW_STATUS BIT(1) +#define POLL_USEC 1000 +#define TIMEOUT_USEC 300000 + +enum { + REG_FREQ_LUT_TABLE, + REG_FREQ_ENABLE, + REG_FREQ_PERF_STATE, + REG_FREQ_HW_STATE, + REG_EM_POWER_TBL, + REG_FREQ_LATENCY, + + REG_ARRAY_SIZE, +}; + +struct cpufreq_mtk { + struct cpufreq_frequency_table *table; + void __iomem *reg_bases[REG_ARRAY_SIZE]; + int nr_opp; + cpumask_t related_cpus; +}; + +static const u16 cpufreq_mtk_offsets[REG_ARRAY_SIZE] = { + [REG_FREQ_LUT_TABLE] = 0x0, + [REG_FREQ_ENABLE] = 0x84, + [REG_FREQ_PERF_STATE] = 0x88, + [REG_FREQ_HW_STATE] = 0x8c, + [REG_EM_POWER_TBL] = 0x90, + [REG_FREQ_LATENCY] = 0x110, +}; + +static struct cpufreq_mtk *mtk_freq_domain_map[NR_CPUS]; + +static int __maybe_unused +mtk_cpufreq_get_cpu_power(unsigned long *mW, + unsigned long *KHz, struct device *cpu_dev) +{ + struct cpufreq_mtk *c = mtk_freq_domain_map[cpu_dev->id]; + int i; + + for (i = 0; i < c->nr_opp; i++) { + if (c->table[i].frequency < *KHz) + break; + } + i--; + + *KHz = c->table[i].frequency; + *mW = readl_relaxed(c->reg_bases[REG_EM_POWER_TBL] + + i * LUT_ROW_SIZE) / 1000; + + return 0; +} + +static int mtk_cpufreq_hw_target_index(struct cpufreq_policy *policy, + unsigned int index) +{ + struct cpufreq_mtk *c = policy->driver_data; + + writel_relaxed(index, c->reg_bases[REG_FREQ_PERF_STATE]); + + return 0; +} + +static unsigned int mtk_cpufreq_hw_get(unsigned int cpu) +{ + struct cpufreq_mtk *c; + unsigned int index; + + c = mtk_freq_domain_map[cpu]; + + index = readl_relaxed(c->reg_bases[REG_FREQ_PERF_STATE]); + index = min(index, LUT_MAX_ENTRIES - 1); + + return c->table[index].frequency; +} + +static unsigned int mtk_cpufreq_hw_fast_switch(struct cpufreq_policy *policy, + unsigned int target_freq) +{ + struct cpufreq_mtk *c = policy->driver_data; + unsigned int index; + + index = cpufreq_table_find_index_dl(policy, target_freq); + + writel_relaxed(index, c->reg_bases[REG_FREQ_PERF_STATE]); + + return policy->freq_table[index].frequency; +} + +static int mtk_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) +{ + struct cpufreq_mtk *c; + struct device *cpu_dev; + struct em_data_callback em_cb = EM_DATA_CB(mtk_cpufreq_get_cpu_power); + struct pm_qos_request *qos_request; + int sig, pwr_hw = CPUFREQ_HW_STATUS | SVS_HW_STATUS; + unsigned int latency; + + qos_request = kzalloc(sizeof(*qos_request), GFP_KERNEL); + if (!qos_request) + return -ENOMEM; + + cpu_dev = get_cpu_device(policy->cpu); + if (!cpu_dev) { + pr_err("failed to get cpu%d device\n", policy->cpu); + return -ENODEV; + } + + c = mtk_freq_domain_map[policy->cpu]; + if (!c) { + pr_err("No scaling support for CPU%d\n", policy->cpu); + return -ENODEV; + } + + cpumask_copy(policy->cpus, &c->related_cpus); + + policy->freq_table = c->table; + policy->driver_data = c; + + latency = readl_relaxed(c->reg_bases[REG_FREQ_LATENCY]); + if (!latency) + latency = CPUFREQ_ETERNAL; + + /* us convert to ns */ + policy->cpuinfo.transition_latency = latency * 1000; + + policy->fast_switch_possible = true; + + /* Let CPUs leave idle-off state for SVS CPU initializing */ + cpu_latency_qos_add_request(qos_request, 0); + + /* HW should be in enabled state to proceed now */ + writel_relaxed(0x1, c->reg_bases[REG_FREQ_ENABLE]); + + if (readl_poll_timeout(c->reg_bases[REG_FREQ_HW_STATE], sig, + (sig & pwr_hw) == pwr_hw, POLL_USEC, + TIMEOUT_USEC)) { + if (!(sig & CPUFREQ_HW_STATUS)) { + pr_info("cpufreq hardware of CPU%d is not enabled\n", + policy->cpu); + return -ENODEV; + } + + pr_info("SVS of CPU%d is not enabled\n", policy->cpu); + } + + em_dev_register_perf_domain(cpu_dev, c->nr_opp, &em_cb, policy->cpus, true); + + cpu_latency_qos_remove_request(qos_request); + kfree(qos_request); + + return 0; +} + +static int mtk_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy) +{ + struct cpufreq_mtk *c; + + c = mtk_freq_domain_map[policy->cpu]; + if (!c) { + pr_err("No scaling support for CPU%d\n", policy->cpu); + return -ENODEV; + } + + /* HW should be in paused state now */ + writel_relaxed(0x0, c->reg_bases[REG_FREQ_ENABLE]); + + return 0; +} + +static struct cpufreq_driver cpufreq_mtk_hw_driver = { + .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK | + CPUFREQ_HAVE_GOVERNOR_PER_POLICY | + CPUFREQ_IS_COOLING_DEV, + .verify = cpufreq_generic_frequency_table_verify, + .target_index = mtk_cpufreq_hw_target_index, + .get = mtk_cpufreq_hw_get, + .init = mtk_cpufreq_hw_cpu_init, + .exit = mtk_cpufreq_hw_cpu_exit, + .fast_switch = mtk_cpufreq_hw_fast_switch, + .name = "mtk-cpufreq-hw", + .attr = cpufreq_generic_attr, +}; + +static int mtk_cpu_create_freq_table(struct platform_device *pdev, + struct cpufreq_mtk *c) +{ + struct device *dev = &pdev->dev; + void __iomem *base_table; + u32 data, i, freq, prev_freq = 0; + + c->table = devm_kcalloc(dev, LUT_MAX_ENTRIES + 1, + sizeof(*c->table), GFP_KERNEL); + if (!c->table) + return -ENOMEM; + + base_table = c->reg_bases[REG_FREQ_LUT_TABLE]; + + for (i = 0; i < LUT_MAX_ENTRIES; i++) { + data = readl_relaxed(base_table + (i * LUT_ROW_SIZE)); + freq = FIELD_GET(LUT_FREQ, data) * 1000; + + if (freq == prev_freq) + break; + + c->table[i].frequency = freq; + + dev_dbg(dev, "index=%d freq=%d\n", + i, c->table[i].frequency); + + prev_freq = freq; + } + + c->table[i].frequency = CPUFREQ_TABLE_END; + c->nr_opp = i; + + return 0; +} + +static int mtk_get_related_cpus(int index, struct cpufreq_mtk *c) +{ + struct device_node *cpu_np; + struct of_phandle_args args; + int cpu, ret; + + for_each_possible_cpu(cpu) { + cpu_np = of_cpu_device_node_get(cpu); + if (!cpu_np) + continue; + + ret = of_parse_phandle_with_args(cpu_np, "performance-domains", + "#performance-domain-cells", 0, + &args); + of_node_put(cpu_np); + if (ret < 0) + continue; + + if (index == args.args[0]) { + cpumask_set_cpu(cpu, &c->related_cpus); + mtk_freq_domain_map[cpu] = c; + } + } + + return 0; +} + +static int mtk_cpu_resources_init(struct platform_device *pdev, + unsigned int cpu, int index, + const u16 *offsets) +{ + struct cpufreq_mtk *c; + struct device *dev = &pdev->dev; + int ret, i; + void __iomem *base; + + if (mtk_freq_domain_map[cpu]) + return 0; + + c = devm_kzalloc(dev, sizeof(*c), GFP_KERNEL); + if (!c) + return -ENOMEM; + + base = devm_platform_ioremap_resource(pdev, index); + if (IS_ERR(base)) + return PTR_ERR(base); + + for (i = REG_FREQ_LUT_TABLE; i < REG_ARRAY_SIZE; i++) + c->reg_bases[i] = base + offsets[i]; + + ret = mtk_get_related_cpus(index, c); + if (ret) { + dev_err(dev, "Domain-%d failed to get related CPUs\n", index); + return ret; + } + + ret = mtk_cpu_create_freq_table(pdev, c); + if (ret) { + dev_err(dev, "Domain-%d failed to create freq table\n", index); + return ret; + } + + return 0; +} + +static int mtk_cpufreq_hw_driver_probe(struct platform_device *pdev) +{ + struct device_node *cpu_np; + struct of_phandle_args args; + const u16 *offsets; + unsigned int cpu; + int ret; + + offsets = of_device_get_match_data(&pdev->dev); + if (!offsets) + return -EINVAL; + + for_each_possible_cpu(cpu) { + cpu_np = of_cpu_device_node_get(cpu); + if (!cpu_np) { + dev_err(&pdev->dev, "Failed to get cpu %d device\n", + cpu); + return -ENODEV; + } + + ret = of_parse_phandle_with_args(cpu_np, "performance-domains", + "#performance-domain-cells", 0, + &args); + if (ret < 0) + return ret; + + /* Get the bases of cpufreq for domains */ + ret = mtk_cpu_resources_init(pdev, cpu, args.args[0], offsets); + if (ret) { + dev_err(&pdev->dev, "CPUFreq resource init failed\n"); + return ret; + } + } + + ret = cpufreq_register_driver(&cpufreq_mtk_hw_driver); + if (ret) { + dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n"); + return ret; + } + + return 0; +} + +static int mtk_cpufreq_hw_driver_remove(struct platform_device *pdev) +{ + return cpufreq_unregister_driver(&cpufreq_mtk_hw_driver); +} + +static const struct of_device_id mtk_cpufreq_hw_match[] = { + { .compatible = "mediatek,cpufreq-hw", .data = &cpufreq_mtk_offsets }, + {} +}; + +static struct platform_driver mtk_cpufreq_hw_driver = { + .probe = mtk_cpufreq_hw_driver_probe, + .remove = mtk_cpufreq_hw_driver_remove, + .driver = { + .name = "mtk-cpufreq-hw", + .of_match_table = mtk_cpufreq_hw_match, + }, +}; +module_platform_driver(mtk_cpufreq_hw_driver); + +MODULE_DESCRIPTION("Mediatek cpufreq-hw driver"); +MODULE_LICENSE("GPL v2"); -- 1.7.9.5