diff options
| -rw-r--r-- | drivers/cpufreq/Kconfig.arm | 11 | ||||
| -rw-r--r-- | drivers/cpufreq/Makefile | 1 | ||||
| -rw-r--r-- | drivers/cpufreq/qcom-cpufreq-hw.c | 308 |
3 files changed, 320 insertions, 0 deletions
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 4e1131ef85ae..688f10227793 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -114,6 +114,17 @@ config ARM_QCOM_CPUFREQ_KRYO If in doubt, say N. +config ARM_QCOM_CPUFREQ_HW + tristate "QCOM CPUFreq HW driver" + depends on ARCH_QCOM || COMPILE_TEST + help + Support for the CPUFreq HW driver. + Some QCOM 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_S3C_CPUFREQ bool help diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index d5ee4562ed06..08c071be2491 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -61,6 +61,7 @@ obj-$(CONFIG_MACH_MVEBU_V7) += mvebu-cpufreq.o obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o obj-$(CONFIG_ARM_PXA2xx_CPUFREQ) += pxa2xx-cpufreq.o obj-$(CONFIG_PXA3xx) += pxa3xx-cpufreq.o +obj-$(CONFIG_ARM_QCOM_CPUFREQ_HW) += qcom-cpufreq-hw.o obj-$(CONFIG_ARM_QCOM_CPUFREQ_KRYO) += qcom-cpufreq-kryo.o obj-$(CONFIG_ARM_S3C2410_CPUFREQ) += s3c2410-cpufreq.o obj-$(CONFIG_ARM_S3C2412_CPUFREQ) += s3c2412-cpufreq.o diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c new file mode 100644 index 000000000000..d83939a1b3d4 --- /dev/null +++ b/drivers/cpufreq/qcom-cpufreq-hw.c @@ -0,0 +1,308 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2018, The Linux Foundation. All rights reserved. + */ + +#include <linux/bitfield.h> +#include <linux/cpufreq.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/slab.h> + +#define LUT_MAX_ENTRIES 40U +#define LUT_SRC GENMASK(31, 30) +#define LUT_L_VAL GENMASK(7, 0) +#define LUT_CORE_COUNT GENMASK(18, 16) +#define LUT_ROW_SIZE 32 +#define CLK_HW_DIV 2 + +/* Register offsets */ +#define REG_ENABLE 0x0 +#define REG_LUT_TABLE 0x110 +#define REG_PERF_STATE 0x920 + +static unsigned long cpu_hw_rate, xo_rate; +static struct platform_device *global_pdev; + +static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy, + unsigned int index) +{ + void __iomem *perf_state_reg = policy->driver_data; + + writel_relaxed(index, perf_state_reg); + + return 0; +} + +static unsigned int qcom_cpufreq_hw_get(unsigned int cpu) +{ + void __iomem *perf_state_reg; + struct cpufreq_policy *policy; + unsigned int index; + + policy = cpufreq_cpu_get_raw(cpu); + if (!policy) + return 0; + + perf_state_reg = policy->driver_data; + + index = readl_relaxed(perf_state_reg); + index = min(index, LUT_MAX_ENTRIES - 1); + + return policy->freq_table[index].frequency; +} + +static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy, + unsigned int target_freq) +{ + void __iomem *perf_state_reg = policy->driver_data; + int index; + + index = policy->cached_resolved_idx; + if (index < 0) + return 0; + + writel_relaxed(index, perf_state_reg); + + return policy->freq_table[index].frequency; +} + +static int qcom_cpufreq_hw_read_lut(struct device *dev, + struct cpufreq_policy *policy, + void __iomem *base) +{ + u32 data, src, lval, i, core_count, prev_cc = 0, prev_freq = 0, freq; + unsigned int max_cores = cpumask_weight(policy->cpus); + struct cpufreq_frequency_table *table; + + table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL); + if (!table) + return -ENOMEM; + + for (i = 0; i < LUT_MAX_ENTRIES; i++) { + data = readl_relaxed(base + REG_LUT_TABLE + i * LUT_ROW_SIZE); + src = FIELD_GET(LUT_SRC, data); + lval = FIELD_GET(LUT_L_VAL, data); + core_count = FIELD_GET(LUT_CORE_COUNT, data); + + if (src) + freq = xo_rate * lval / 1000; + else + freq = cpu_hw_rate / 1000; + + /* Ignore boosts in the middle of the table */ + if (core_count != max_cores) { + table[i].frequency = CPUFREQ_ENTRY_INVALID; + } else { + table[i].frequency = freq; + dev_dbg(dev, "index=%d freq=%d, core_count %d\n", i, + freq, core_count); + } + + /* + * Two of the same frequencies with the same core counts means + * end of table + */ + if (i > 0 && prev_freq == freq && prev_cc == core_count) { + struct cpufreq_frequency_table *prev = &table[i - 1]; + + /* + * Only treat the last frequency that might be a boost + * as the boost frequency + */ + if (prev_cc != max_cores) { + prev->frequency = prev_freq; + prev->flags = CPUFREQ_BOOST_FREQ; + } + + break; + } + + prev_cc = core_count; + prev_freq = freq; + } + + table[i].frequency = CPUFREQ_TABLE_END; + policy->freq_table = table; + + return 0; +} + +static void qcom_get_related_cpus(int index, struct cpumask *m) +{ + 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, "qcom,freq-domain", + "#freq-domain-cells", 0, + &args); + of_node_put(cpu_np); + if (ret < 0) + continue; + + if (index == args.args[0]) + cpumask_set_cpu(cpu, m); + } +} + +static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) +{ + struct device *dev = &global_pdev->dev; + struct of_phandle_args args; + struct device_node *cpu_np; + struct resource *res; + void __iomem *base; + int ret, index; + + cpu_np = of_cpu_device_node_get(policy->cpu); + if (!cpu_np) + return -EINVAL; + + ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain", + "#freq-domain-cells", 0, &args); + of_node_put(cpu_np); + if (ret) + return ret; + + index = args.args[0]; + + res = platform_get_resource(global_pdev, IORESOURCE_MEM, index); + if (!res) + return -ENODEV; + + base = devm_ioremap(dev, res->start, resource_size(res)); + if (!base) + return -ENOMEM; + + /* HW should be in enabled state to proceed */ + if (!(readl_relaxed(base + REG_ENABLE) & 0x1)) { + dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index); + ret = -ENODEV; + goto error; + } + + qcom_get_related_cpus(index, policy->cpus); + if (!cpumask_weight(policy->cpus)) { + dev_err(dev, "Domain-%d failed to get related CPUs\n", index); + ret = -ENOENT; + goto error; + } + + policy->driver_data = base + REG_PERF_STATE; + + ret = qcom_cpufreq_hw_read_lut(dev, policy, base); + if (ret) { + dev_err(dev, "Domain-%d failed to read LUT\n", index); + goto error; + } + + policy->fast_switch_possible = true; + + return 0; +error: + devm_iounmap(dev, base); + return ret; +} + +static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy) +{ + void __iomem *base = policy->driver_data - REG_PERF_STATE; + + kfree(policy->freq_table); + devm_iounmap(&global_pdev->dev, base); + + return 0; +} + +static struct freq_attr *qcom_cpufreq_hw_attr[] = { + &cpufreq_freq_attr_scaling_available_freqs, + &cpufreq_freq_attr_scaling_boost_freqs, + NULL +}; + +static struct cpufreq_driver cpufreq_qcom_hw_driver = { + .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK | + CPUFREQ_HAVE_GOVERNOR_PER_POLICY, + .verify = cpufreq_generic_frequency_table_verify, + .target_index = qcom_cpufreq_hw_target_index, + .get = qcom_cpufreq_hw_get, + .init = qcom_cpufreq_hw_cpu_init, + .exit = qcom_cpufreq_hw_cpu_exit, + .fast_switch = qcom_cpufreq_hw_fast_switch, + .name = "qcom-cpufreq-hw", + .attr = qcom_cpufreq_hw_attr, +}; + +static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev) +{ + struct clk *clk; + int ret; + + clk = clk_get(&pdev->dev, "xo"); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + xo_rate = clk_get_rate(clk); + clk_put(clk); + + clk = clk_get(&pdev->dev, "alternate"); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV; + clk_put(clk); + + global_pdev = pdev; + + ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver); + if (ret) + dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n"); + else + dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n"); + + return ret; +} + +static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev) +{ + return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver); +} + +static const struct of_device_id qcom_cpufreq_hw_match[] = { + { .compatible = "qcom,cpufreq-hw" }, + {} +}; +MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match); + +static struct platform_driver qcom_cpufreq_hw_driver = { + .probe = qcom_cpufreq_hw_driver_probe, + .remove = qcom_cpufreq_hw_driver_remove, + .driver = { + .name = "qcom-cpufreq-hw", + .of_match_table = qcom_cpufreq_hw_match, + }, +}; + +static int __init qcom_cpufreq_hw_init(void) +{ + return platform_driver_register(&qcom_cpufreq_hw_driver); +} +subsys_initcall(qcom_cpufreq_hw_init); + +static void __exit qcom_cpufreq_hw_exit(void) +{ + platform_driver_unregister(&qcom_cpufreq_hw_driver); +} +module_exit(qcom_cpufreq_hw_exit); + +MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver"); +MODULE_LICENSE("GPL v2"); |