diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/cpufreq/tegra194-cpufreq.c | 607 |
1 files changed, 607 insertions, 0 deletions
diff --git a/drivers/cpufreq/tegra194-cpufreq.c b/drivers/cpufreq/tegra194-cpufreq.c new file mode 100644 index 000000000..4596c3e32 --- /dev/null +++ b/drivers/cpufreq/tegra194-cpufreq.c @@ -0,0 +1,607 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2020 - 2022, NVIDIA CORPORATION. All rights reserved + */ + +#include <linux/cpu.h> +#include <linux/cpufreq.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include <asm/smp_plat.h> + +#include <soc/tegra/bpmp.h> +#include <soc/tegra/bpmp-abi.h> + +#define KHZ 1000 +#define REF_CLK_MHZ 408 /* 408 MHz */ +#define US_DELAY 500 +#define CPUFREQ_TBL_STEP_HZ (50 * KHZ * KHZ) +#define MAX_CNT ~0U + +#define NDIV_MASK 0x1FF + +#define CORE_OFFSET(cpu) (cpu * 8) +#define CMU_CLKS_BASE 0x2000 +#define SCRATCH_FREQ_CORE_REG(data, cpu) (data->regs + CMU_CLKS_BASE + CORE_OFFSET(cpu)) + +#define MMCRAB_CLUSTER_BASE(cl) (0x30000 + (cl * 0x10000)) +#define CLUSTER_ACTMON_BASE(data, cl) \ + (data->regs + (MMCRAB_CLUSTER_BASE(cl) + data->soc->actmon_cntr_base)) +#define CORE_ACTMON_CNTR_REG(data, cl, cpu) (CLUSTER_ACTMON_BASE(data, cl) + CORE_OFFSET(cpu)) + +/* cpufreq transisition latency */ +#define TEGRA_CPUFREQ_TRANSITION_LATENCY (300 * 1000) /* unit in nanoseconds */ + +struct tegra_cpu_ctr { + u32 cpu; + u32 coreclk_cnt, last_coreclk_cnt; + u32 refclk_cnt, last_refclk_cnt; +}; + +struct read_counters_work { + struct work_struct work; + struct tegra_cpu_ctr c; +}; + +struct tegra_cpufreq_ops { + void (*read_counters)(struct tegra_cpu_ctr *c); + void (*set_cpu_ndiv)(struct cpufreq_policy *policy, u64 ndiv); + void (*get_cpu_cluster_id)(u32 cpu, u32 *cpuid, u32 *clusterid); + int (*get_cpu_ndiv)(u32 cpu, u32 cpuid, u32 clusterid, u64 *ndiv); +}; + +struct tegra_cpufreq_soc { + struct tegra_cpufreq_ops *ops; + int maxcpus_per_cluster; + unsigned int num_clusters; + phys_addr_t actmon_cntr_base; +}; + +struct tegra194_cpufreq_data { + void __iomem *regs; + struct cpufreq_frequency_table **tables; + const struct tegra_cpufreq_soc *soc; +}; + +static struct workqueue_struct *read_counters_wq; + +static void tegra_get_cpu_mpidr(void *mpidr) +{ + *((u64 *)mpidr) = read_cpuid_mpidr() & MPIDR_HWID_BITMASK; +} + +static void tegra234_get_cpu_cluster_id(u32 cpu, u32 *cpuid, u32 *clusterid) +{ + u64 mpidr; + + smp_call_function_single(cpu, tegra_get_cpu_mpidr, &mpidr, true); + + if (cpuid) + *cpuid = MPIDR_AFFINITY_LEVEL(mpidr, 1); + if (clusterid) + *clusterid = MPIDR_AFFINITY_LEVEL(mpidr, 2); +} + +static int tegra234_get_cpu_ndiv(u32 cpu, u32 cpuid, u32 clusterid, u64 *ndiv) +{ + struct tegra194_cpufreq_data *data = cpufreq_get_driver_data(); + void __iomem *freq_core_reg; + u64 mpidr_id; + + /* use physical id to get address of per core frequency register */ + mpidr_id = (clusterid * data->soc->maxcpus_per_cluster) + cpuid; + freq_core_reg = SCRATCH_FREQ_CORE_REG(data, mpidr_id); + + *ndiv = readl(freq_core_reg) & NDIV_MASK; + + return 0; +} + +static void tegra234_set_cpu_ndiv(struct cpufreq_policy *policy, u64 ndiv) +{ + struct tegra194_cpufreq_data *data = cpufreq_get_driver_data(); + void __iomem *freq_core_reg; + u32 cpu, cpuid, clusterid; + u64 mpidr_id; + + for_each_cpu_and(cpu, policy->cpus, cpu_online_mask) { + data->soc->ops->get_cpu_cluster_id(cpu, &cpuid, &clusterid); + + /* use physical id to get address of per core frequency register */ + mpidr_id = (clusterid * data->soc->maxcpus_per_cluster) + cpuid; + freq_core_reg = SCRATCH_FREQ_CORE_REG(data, mpidr_id); + + writel(ndiv, freq_core_reg); + } +} + +/* + * This register provides access to two counter values with a single + * 64-bit read. The counter values are used to determine the average + * actual frequency a core has run at over a period of time. + * [63:32] PLLP counter: Counts at fixed frequency (408 MHz) + * [31:0] Core clock counter: Counts on every core clock cycle + */ +static void tegra234_read_counters(struct tegra_cpu_ctr *c) +{ + struct tegra194_cpufreq_data *data = cpufreq_get_driver_data(); + void __iomem *actmon_reg; + u32 cpuid, clusterid; + u64 val; + + data->soc->ops->get_cpu_cluster_id(c->cpu, &cpuid, &clusterid); + actmon_reg = CORE_ACTMON_CNTR_REG(data, clusterid, cpuid); + + val = readq(actmon_reg); + c->last_refclk_cnt = upper_32_bits(val); + c->last_coreclk_cnt = lower_32_bits(val); + udelay(US_DELAY); + val = readq(actmon_reg); + c->refclk_cnt = upper_32_bits(val); + c->coreclk_cnt = lower_32_bits(val); +} + +static struct tegra_cpufreq_ops tegra234_cpufreq_ops = { + .read_counters = tegra234_read_counters, + .get_cpu_cluster_id = tegra234_get_cpu_cluster_id, + .get_cpu_ndiv = tegra234_get_cpu_ndiv, + .set_cpu_ndiv = tegra234_set_cpu_ndiv, +}; + +static const struct tegra_cpufreq_soc tegra234_cpufreq_soc = { + .ops = &tegra234_cpufreq_ops, + .actmon_cntr_base = 0x9000, + .maxcpus_per_cluster = 4, + .num_clusters = 3, +}; + +static const struct tegra_cpufreq_soc tegra239_cpufreq_soc = { + .ops = &tegra234_cpufreq_ops, + .actmon_cntr_base = 0x4000, + .maxcpus_per_cluster = 8, + .num_clusters = 1, +}; + +static void tegra194_get_cpu_cluster_id(u32 cpu, u32 *cpuid, u32 *clusterid) +{ + u64 mpidr; + + smp_call_function_single(cpu, tegra_get_cpu_mpidr, &mpidr, true); + + if (cpuid) + *cpuid = MPIDR_AFFINITY_LEVEL(mpidr, 0); + if (clusterid) + *clusterid = MPIDR_AFFINITY_LEVEL(mpidr, 1); +} + +/* + * Read per-core Read-only system register NVFREQ_FEEDBACK_EL1. + * The register provides frequency feedback information to + * determine the average actual frequency a core has run at over + * a period of time. + * [31:0] PLLP counter: Counts at fixed frequency (408 MHz) + * [63:32] Core clock counter: counts on every core clock cycle + * where the core is architecturally clocking + */ +static u64 read_freq_feedback(void) +{ + u64 val = 0; + + asm volatile("mrs %0, s3_0_c15_c0_5" : "=r" (val) : ); + + return val; +} + +static inline u32 map_ndiv_to_freq(struct mrq_cpu_ndiv_limits_response + *nltbl, u16 ndiv) +{ + return nltbl->ref_clk_hz / KHZ * ndiv / (nltbl->pdiv * nltbl->mdiv); +} + +static void tegra194_read_counters(struct tegra_cpu_ctr *c) +{ + u64 val; + + val = read_freq_feedback(); + c->last_refclk_cnt = lower_32_bits(val); + c->last_coreclk_cnt = upper_32_bits(val); + udelay(US_DELAY); + val = read_freq_feedback(); + c->refclk_cnt = lower_32_bits(val); + c->coreclk_cnt = upper_32_bits(val); +} + +static void tegra_read_counters(struct work_struct *work) +{ + struct tegra194_cpufreq_data *data = cpufreq_get_driver_data(); + struct read_counters_work *read_counters_work; + struct tegra_cpu_ctr *c; + + /* + * ref_clk_counter(32 bit counter) runs on constant clk, + * pll_p(408MHz). + * It will take = 2 ^ 32 / 408 MHz to overflow ref clk counter + * = 10526880 usec = 10.527 sec to overflow + * + * Like wise core_clk_counter(32 bit counter) runs on core clock. + * It's synchronized to crab_clk (cpu_crab_clk) which runs at + * freq of cluster. Assuming max cluster clock ~2000MHz, + * It will take = 2 ^ 32 / 2000 MHz to overflow core clk counter + * = ~2.147 sec to overflow + */ + read_counters_work = container_of(work, struct read_counters_work, + work); + c = &read_counters_work->c; + + data->soc->ops->read_counters(c); +} + +/* + * Return instantaneous cpu speed + * Instantaneous freq is calculated as - + * -Takes sample on every query of getting the freq. + * - Read core and ref clock counters; + * - Delay for X us + * - Read above cycle counters again + * - Calculates freq by subtracting current and previous counters + * divided by the delay time or eqv. of ref_clk_counter in delta time + * - Return Kcycles/second, freq in KHz + * + * delta time period = x sec + * = delta ref_clk_counter / (408 * 10^6) sec + * freq in Hz = cycles/sec + * = (delta cycles / x sec + * = (delta cycles * 408 * 10^6) / delta ref_clk_counter + * in KHz = (delta cycles * 408 * 10^3) / delta ref_clk_counter + * + * @cpu - logical cpu whose freq to be updated + * Returns freq in KHz on success, 0 if cpu is offline + */ +static unsigned int tegra194_calculate_speed(u32 cpu) +{ + struct read_counters_work read_counters_work; + struct tegra_cpu_ctr c; + u32 delta_refcnt; + u32 delta_ccnt; + u32 rate_mhz; + + /* + * udelay() is required to reconstruct cpu frequency over an + * observation window. Using workqueue to call udelay() with + * interrupts enabled. + */ + read_counters_work.c.cpu = cpu; + INIT_WORK_ONSTACK(&read_counters_work.work, tegra_read_counters); + queue_work_on(cpu, read_counters_wq, &read_counters_work.work); + flush_work(&read_counters_work.work); + c = read_counters_work.c; + + if (c.coreclk_cnt < c.last_coreclk_cnt) + delta_ccnt = c.coreclk_cnt + (MAX_CNT - c.last_coreclk_cnt); + else + delta_ccnt = c.coreclk_cnt - c.last_coreclk_cnt; + if (!delta_ccnt) + return 0; + + /* ref clock is 32 bits */ + if (c.refclk_cnt < c.last_refclk_cnt) + delta_refcnt = c.refclk_cnt + (MAX_CNT - c.last_refclk_cnt); + else + delta_refcnt = c.refclk_cnt - c.last_refclk_cnt; + if (!delta_refcnt) { + pr_debug("cpufreq: %d is idle, delta_refcnt: 0\n", cpu); + return 0; + } + rate_mhz = ((unsigned long)(delta_ccnt * REF_CLK_MHZ)) / delta_refcnt; + + return (rate_mhz * KHZ); /* in KHz */ +} + +static void tegra194_get_cpu_ndiv_sysreg(void *ndiv) +{ + u64 ndiv_val; + + asm volatile("mrs %0, s3_0_c15_c0_4" : "=r" (ndiv_val) : ); + + *(u64 *)ndiv = ndiv_val; +} + +static int tegra194_get_cpu_ndiv(u32 cpu, u32 cpuid, u32 clusterid, u64 *ndiv) +{ + return smp_call_function_single(cpu, tegra194_get_cpu_ndiv_sysreg, &ndiv, true); +} + +static void tegra194_set_cpu_ndiv_sysreg(void *data) +{ + u64 ndiv_val = *(u64 *)data; + + asm volatile("msr s3_0_c15_c0_4, %0" : : "r" (ndiv_val)); +} + +static void tegra194_set_cpu_ndiv(struct cpufreq_policy *policy, u64 ndiv) +{ + on_each_cpu_mask(policy->cpus, tegra194_set_cpu_ndiv_sysreg, &ndiv, true); +} + +static unsigned int tegra194_get_speed(u32 cpu) +{ + struct tegra194_cpufreq_data *data = cpufreq_get_driver_data(); + struct cpufreq_frequency_table *pos; + u32 cpuid, clusterid; + unsigned int rate; + u64 ndiv; + int ret; + + data->soc->ops->get_cpu_cluster_id(cpu, &cpuid, &clusterid); + + /* reconstruct actual cpu freq using counters */ + rate = tegra194_calculate_speed(cpu); + + /* get last written ndiv value */ + ret = data->soc->ops->get_cpu_ndiv(cpu, cpuid, clusterid, &ndiv); + if (WARN_ON_ONCE(ret)) + return rate; + + /* + * If the reconstructed frequency has acceptable delta from + * the last written value, then return freq corresponding + * to the last written ndiv value from freq_table. This is + * done to return consistent value. + */ + cpufreq_for_each_valid_entry(pos, data->tables[clusterid]) { + if (pos->driver_data != ndiv) + continue; + + if (abs(pos->frequency - rate) > 115200) { + pr_warn("cpufreq: cpu%d,cur:%u,set:%u,set ndiv:%llu\n", + cpu, rate, pos->frequency, ndiv); + } else { + rate = pos->frequency; + } + break; + } + return rate; +} + +static int tegra194_cpufreq_init(struct cpufreq_policy *policy) +{ + struct tegra194_cpufreq_data *data = cpufreq_get_driver_data(); + int maxcpus_per_cluster = data->soc->maxcpus_per_cluster; + u32 start_cpu, cpu; + u32 clusterid; + + data->soc->ops->get_cpu_cluster_id(policy->cpu, NULL, &clusterid); + + if (clusterid >= data->soc->num_clusters || !data->tables[clusterid]) + return -EINVAL; + + start_cpu = rounddown(policy->cpu, maxcpus_per_cluster); + /* set same policy for all cpus in a cluster */ + for (cpu = start_cpu; cpu < (start_cpu + maxcpus_per_cluster); cpu++) { + if (cpu_possible(cpu)) + cpumask_set_cpu(cpu, policy->cpus); + } + policy->freq_table = data->tables[clusterid]; + policy->cpuinfo.transition_latency = TEGRA_CPUFREQ_TRANSITION_LATENCY; + + return 0; +} + +static int tegra194_cpufreq_set_target(struct cpufreq_policy *policy, + unsigned int index) +{ + struct cpufreq_frequency_table *tbl = policy->freq_table + index; + struct tegra194_cpufreq_data *data = cpufreq_get_driver_data(); + + /* + * Each core writes frequency in per core register. Then both cores + * in a cluster run at same frequency which is the maximum frequency + * request out of the values requested by both cores in that cluster. + */ + data->soc->ops->set_cpu_ndiv(policy, (u64)tbl->driver_data); + + return 0; +} + +static struct cpufreq_driver tegra194_cpufreq_driver = { + .name = "tegra194", + .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_INITIAL_FREQ_CHECK, + .verify = cpufreq_generic_frequency_table_verify, + .target_index = tegra194_cpufreq_set_target, + .get = tegra194_get_speed, + .init = tegra194_cpufreq_init, + .attr = cpufreq_generic_attr, +}; + +static struct tegra_cpufreq_ops tegra194_cpufreq_ops = { + .read_counters = tegra194_read_counters, + .get_cpu_cluster_id = tegra194_get_cpu_cluster_id, + .get_cpu_ndiv = tegra194_get_cpu_ndiv, + .set_cpu_ndiv = tegra194_set_cpu_ndiv, +}; + +static const struct tegra_cpufreq_soc tegra194_cpufreq_soc = { + .ops = &tegra194_cpufreq_ops, + .maxcpus_per_cluster = 2, + .num_clusters = 4, +}; + +static void tegra194_cpufreq_free_resources(void) +{ + destroy_workqueue(read_counters_wq); +} + +static struct cpufreq_frequency_table * +init_freq_table(struct platform_device *pdev, struct tegra_bpmp *bpmp, + unsigned int cluster_id) +{ + struct cpufreq_frequency_table *freq_table; + struct mrq_cpu_ndiv_limits_response resp; + unsigned int num_freqs, ndiv, delta_ndiv; + struct mrq_cpu_ndiv_limits_request req; + struct tegra_bpmp_message msg; + u16 freq_table_step_size; + int err, index; + + memset(&req, 0, sizeof(req)); + req.cluster_id = cluster_id; + + memset(&msg, 0, sizeof(msg)); + msg.mrq = MRQ_CPU_NDIV_LIMITS; + msg.tx.data = &req; + msg.tx.size = sizeof(req); + msg.rx.data = &resp; + msg.rx.size = sizeof(resp); + + err = tegra_bpmp_transfer(bpmp, &msg); + if (err) + return ERR_PTR(err); + if (msg.rx.ret == -BPMP_EINVAL) { + /* Cluster not available */ + return NULL; + } + if (msg.rx.ret) + return ERR_PTR(-EINVAL); + + /* + * Make sure frequency table step is a multiple of mdiv to match + * vhint table granularity. + */ + freq_table_step_size = resp.mdiv * + DIV_ROUND_UP(CPUFREQ_TBL_STEP_HZ, resp.ref_clk_hz); + + dev_dbg(&pdev->dev, "cluster %d: frequency table step size: %d\n", + cluster_id, freq_table_step_size); + + delta_ndiv = resp.ndiv_max - resp.ndiv_min; + + if (unlikely(delta_ndiv == 0)) { + num_freqs = 1; + } else { + /* We store both ndiv_min and ndiv_max hence the +1 */ + num_freqs = delta_ndiv / freq_table_step_size + 1; + } + + num_freqs += (delta_ndiv % freq_table_step_size) ? 1 : 0; + + freq_table = devm_kcalloc(&pdev->dev, num_freqs + 1, + sizeof(*freq_table), GFP_KERNEL); + if (!freq_table) + return ERR_PTR(-ENOMEM); + + for (index = 0, ndiv = resp.ndiv_min; + ndiv < resp.ndiv_max; + index++, ndiv += freq_table_step_size) { + freq_table[index].driver_data = ndiv; + freq_table[index].frequency = map_ndiv_to_freq(&resp, ndiv); + } + + freq_table[index].driver_data = resp.ndiv_max; + freq_table[index++].frequency = map_ndiv_to_freq(&resp, resp.ndiv_max); + freq_table[index].frequency = CPUFREQ_TABLE_END; + + return freq_table; +} + +static int tegra194_cpufreq_probe(struct platform_device *pdev) +{ + const struct tegra_cpufreq_soc *soc; + struct tegra194_cpufreq_data *data; + struct tegra_bpmp *bpmp; + int err, i; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + soc = of_device_get_match_data(&pdev->dev); + + if (soc->ops && soc->maxcpus_per_cluster && soc->num_clusters) { + data->soc = soc; + } else { + dev_err(&pdev->dev, "soc data missing\n"); + return -EINVAL; + } + + data->tables = devm_kcalloc(&pdev->dev, data->soc->num_clusters, + sizeof(*data->tables), GFP_KERNEL); + if (!data->tables) + return -ENOMEM; + + if (soc->actmon_cntr_base) { + /* mmio registers are used for frequency request and re-construction */ + data->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(data->regs)) + return PTR_ERR(data->regs); + } + + platform_set_drvdata(pdev, data); + + bpmp = tegra_bpmp_get(&pdev->dev); + if (IS_ERR(bpmp)) + return PTR_ERR(bpmp); + + read_counters_wq = alloc_workqueue("read_counters_wq", __WQ_LEGACY, 1); + if (!read_counters_wq) { + dev_err(&pdev->dev, "fail to create_workqueue\n"); + err = -EINVAL; + goto put_bpmp; + } + + for (i = 0; i < data->soc->num_clusters; i++) { + data->tables[i] = init_freq_table(pdev, bpmp, i); + if (IS_ERR(data->tables[i])) { + err = PTR_ERR(data->tables[i]); + goto err_free_res; + } + } + + tegra194_cpufreq_driver.driver_data = data; + + err = cpufreq_register_driver(&tegra194_cpufreq_driver); + if (!err) + goto put_bpmp; + +err_free_res: + tegra194_cpufreq_free_resources(); +put_bpmp: + tegra_bpmp_put(bpmp); + return err; +} + +static int tegra194_cpufreq_remove(struct platform_device *pdev) +{ + cpufreq_unregister_driver(&tegra194_cpufreq_driver); + tegra194_cpufreq_free_resources(); + + return 0; +} + +static const struct of_device_id tegra194_cpufreq_of_match[] = { + { .compatible = "nvidia,tegra194-ccplex", .data = &tegra194_cpufreq_soc }, + { .compatible = "nvidia,tegra234-ccplex-cluster", .data = &tegra234_cpufreq_soc }, + { .compatible = "nvidia,tegra239-ccplex-cluster", .data = &tegra239_cpufreq_soc }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, tegra194_cpufreq_of_match); + +static struct platform_driver tegra194_ccplex_driver = { + .driver = { + .name = "tegra194-cpufreq", + .of_match_table = tegra194_cpufreq_of_match, + }, + .probe = tegra194_cpufreq_probe, + .remove = tegra194_cpufreq_remove, +}; +module_platform_driver(tegra194_ccplex_driver); + +MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>"); +MODULE_AUTHOR("Sumit Gupta <sumitg@nvidia.com>"); +MODULE_DESCRIPTION("NVIDIA Tegra194 cpufreq driver"); +MODULE_LICENSE("GPL v2"); |