| /* |
| * Copyright 2013 Freescale Semiconductor, Inc. |
| * |
| * CPU Frequency Scaling driver for Freescale QorIQ SoCs. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/clk.h> |
| #include <linux/clk-provider.h> |
| #include <linux/cpufreq.h> |
| #include <linux/cpu_cooling.h> |
| #include <linux/errno.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/of.h> |
| #include <linux/slab.h> |
| #include <linux/smp.h> |
| |
| /** |
| * struct cpu_data |
| * @pclk: the parent clock of cpu |
| * @table: frequency table |
| */ |
| struct cpu_data { |
| struct clk **pclk; |
| struct cpufreq_frequency_table *table; |
| struct thermal_cooling_device *cdev; |
| }; |
| |
| /* |
| * Don't use cpufreq on this SoC -- used when the SoC would have otherwise |
| * matched a more generic compatible. |
| */ |
| #define SOC_BLACKLIST 1 |
| |
| /** |
| * struct soc_data - SoC specific data |
| * @flags: SOC_xxx |
| */ |
| struct soc_data { |
| u32 flags; |
| }; |
| |
| static u32 get_bus_freq(void) |
| { |
| struct device_node *soc; |
| u32 sysfreq; |
| |
| soc = of_find_node_by_type(NULL, "soc"); |
| if (!soc) |
| return 0; |
| |
| if (of_property_read_u32(soc, "bus-frequency", &sysfreq)) |
| sysfreq = 0; |
| |
| of_node_put(soc); |
| |
| return sysfreq; |
| } |
| |
| static struct clk *cpu_to_clk(int cpu) |
| { |
| struct device_node *np; |
| struct clk *clk; |
| |
| if (!cpu_present(cpu)) |
| return NULL; |
| |
| np = of_get_cpu_node(cpu, NULL); |
| if (!np) |
| return NULL; |
| |
| clk = of_clk_get(np, 0); |
| of_node_put(np); |
| return clk; |
| } |
| |
| /* traverse cpu nodes to get cpu mask of sharing clock wire */ |
| static void set_affected_cpus(struct cpufreq_policy *policy) |
| { |
| struct cpumask *dstp = policy->cpus; |
| struct clk *clk; |
| int i; |
| |
| for_each_present_cpu(i) { |
| clk = cpu_to_clk(i); |
| if (IS_ERR(clk)) { |
| pr_err("%s: no clock for cpu %d\n", __func__, i); |
| continue; |
| } |
| |
| if (clk_is_match(policy->clk, clk)) |
| cpumask_set_cpu(i, dstp); |
| } |
| } |
| |
| /* reduce the duplicated frequencies in frequency table */ |
| static void freq_table_redup(struct cpufreq_frequency_table *freq_table, |
| int count) |
| { |
| int i, j; |
| |
| for (i = 1; i < count; i++) { |
| for (j = 0; j < i; j++) { |
| if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID || |
| freq_table[j].frequency != |
| freq_table[i].frequency) |
| continue; |
| |
| freq_table[i].frequency = CPUFREQ_ENTRY_INVALID; |
| break; |
| } |
| } |
| } |
| |
| /* sort the frequencies in frequency table in descenting order */ |
| static void freq_table_sort(struct cpufreq_frequency_table *freq_table, |
| int count) |
| { |
| int i, j, ind; |
| unsigned int freq, max_freq; |
| struct cpufreq_frequency_table table; |
| |
| for (i = 0; i < count - 1; i++) { |
| max_freq = freq_table[i].frequency; |
| ind = i; |
| for (j = i + 1; j < count; j++) { |
| freq = freq_table[j].frequency; |
| if (freq == CPUFREQ_ENTRY_INVALID || |
| freq <= max_freq) |
| continue; |
| ind = j; |
| max_freq = freq; |
| } |
| |
| if (ind != i) { |
| /* exchange the frequencies */ |
| table.driver_data = freq_table[i].driver_data; |
| table.frequency = freq_table[i].frequency; |
| freq_table[i].driver_data = freq_table[ind].driver_data; |
| freq_table[i].frequency = freq_table[ind].frequency; |
| freq_table[ind].driver_data = table.driver_data; |
| freq_table[ind].frequency = table.frequency; |
| } |
| } |
| } |
| |
| static int qoriq_cpufreq_cpu_init(struct cpufreq_policy *policy) |
| { |
| struct device_node *np; |
| int i, count, ret; |
| u32 freq; |
| struct clk *clk; |
| const struct clk_hw *hwclk; |
| struct cpufreq_frequency_table *table; |
| struct cpu_data *data; |
| unsigned int cpu = policy->cpu; |
| u64 u64temp; |
| |
| np = of_get_cpu_node(cpu, NULL); |
| if (!np) |
| return -ENODEV; |
| |
| data = kzalloc(sizeof(*data), GFP_KERNEL); |
| if (!data) |
| goto err_np; |
| |
| policy->clk = of_clk_get(np, 0); |
| if (IS_ERR(policy->clk)) { |
| pr_err("%s: no clock information\n", __func__); |
| goto err_nomem2; |
| } |
| |
| hwclk = __clk_get_hw(policy->clk); |
| count = clk_hw_get_num_parents(hwclk); |
| |
| data->pclk = kcalloc(count, sizeof(struct clk *), GFP_KERNEL); |
| if (!data->pclk) { |
| pr_err("%s: no memory\n", __func__); |
| goto err_nomem2; |
| } |
| |
| table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL); |
| if (!table) { |
| pr_err("%s: no memory\n", __func__); |
| goto err_pclk; |
| } |
| |
| for (i = 0; i < count; i++) { |
| clk = clk_hw_get_parent_by_index(hwclk, i)->clk; |
| data->pclk[i] = clk; |
| freq = clk_get_rate(clk); |
| table[i].frequency = freq / 1000; |
| table[i].driver_data = i; |
| } |
| freq_table_redup(table, count); |
| freq_table_sort(table, count); |
| table[i].frequency = CPUFREQ_TABLE_END; |
| |
| /* set the min and max frequency properly */ |
| ret = cpufreq_table_validate_and_show(policy, table); |
| if (ret) { |
| pr_err("invalid frequency table: %d\n", ret); |
| goto err_nomem1; |
| } |
| |
| data->table = table; |
| |
| /* update ->cpus if we have cluster, no harm if not */ |
| set_affected_cpus(policy); |
| policy->driver_data = data; |
| |
| /* Minimum transition latency is 12 platform clocks */ |
| u64temp = 12ULL * NSEC_PER_SEC; |
| do_div(u64temp, get_bus_freq()); |
| policy->cpuinfo.transition_latency = u64temp + 1; |
| |
| of_node_put(np); |
| |
| return 0; |
| |
| err_nomem1: |
| kfree(table); |
| err_pclk: |
| kfree(data->pclk); |
| err_nomem2: |
| kfree(data); |
| err_np: |
| of_node_put(np); |
| |
| return -ENODEV; |
| } |
| |
| static int qoriq_cpufreq_cpu_exit(struct cpufreq_policy *policy) |
| { |
| struct cpu_data *data = policy->driver_data; |
| |
| cpufreq_cooling_unregister(data->cdev); |
| kfree(data->pclk); |
| kfree(data->table); |
| kfree(data); |
| policy->driver_data = NULL; |
| |
| return 0; |
| } |
| |
| static int qoriq_cpufreq_target(struct cpufreq_policy *policy, |
| unsigned int index) |
| { |
| struct clk *parent; |
| struct cpu_data *data = policy->driver_data; |
| |
| parent = data->pclk[data->table[index].driver_data]; |
| return clk_set_parent(policy->clk, parent); |
| } |
| |
| |
| static void qoriq_cpufreq_ready(struct cpufreq_policy *policy) |
| { |
| struct cpu_data *cpud = policy->driver_data; |
| struct device_node *np = of_get_cpu_node(policy->cpu, NULL); |
| |
| if (of_find_property(np, "#cooling-cells", NULL)) { |
| cpud->cdev = of_cpufreq_cooling_register(np, |
| policy->related_cpus); |
| |
| if (IS_ERR(cpud->cdev) && PTR_ERR(cpud->cdev) != -ENOSYS) { |
| pr_err("cpu%d is not running as cooling device: %ld\n", |
| policy->cpu, PTR_ERR(cpud->cdev)); |
| |
| cpud->cdev = NULL; |
| } |
| } |
| |
| of_node_put(np); |
| } |
| |
| static struct cpufreq_driver qoriq_cpufreq_driver = { |
| .name = "qoriq_cpufreq", |
| .flags = CPUFREQ_CONST_LOOPS, |
| .init = qoriq_cpufreq_cpu_init, |
| .exit = qoriq_cpufreq_cpu_exit, |
| .verify = cpufreq_generic_frequency_table_verify, |
| .target_index = qoriq_cpufreq_target, |
| .get = cpufreq_generic_get, |
| .ready = qoriq_cpufreq_ready, |
| .attr = cpufreq_generic_attr, |
| }; |
| |
| static const struct soc_data blacklist = { |
| .flags = SOC_BLACKLIST, |
| }; |
| |
| static const struct of_device_id node_matches[] __initconst = { |
| /* e6500 cannot use cpufreq due to erratum A-008083 */ |
| { .compatible = "fsl,b4420-clockgen", &blacklist }, |
| { .compatible = "fsl,b4860-clockgen", &blacklist }, |
| { .compatible = "fsl,t2080-clockgen", &blacklist }, |
| { .compatible = "fsl,t4240-clockgen", &blacklist }, |
| |
| { .compatible = "fsl,ls1012a-clockgen", }, |
| { .compatible = "fsl,ls1021a-clockgen", }, |
| { .compatible = "fsl,ls1043a-clockgen", }, |
| { .compatible = "fsl,ls1046a-clockgen", }, |
| { .compatible = "fsl,ls1088a-clockgen", }, |
| { .compatible = "fsl,ls2080a-clockgen", }, |
| { .compatible = "fsl,p4080-clockgen", }, |
| { .compatible = "fsl,qoriq-clockgen-1.0", }, |
| { .compatible = "fsl,qoriq-clockgen-2.0", }, |
| {} |
| }; |
| |
| static int __init qoriq_cpufreq_init(void) |
| { |
| int ret; |
| struct device_node *np; |
| const struct of_device_id *match; |
| const struct soc_data *data; |
| |
| np = of_find_matching_node(NULL, node_matches); |
| if (!np) |
| return -ENODEV; |
| |
| match = of_match_node(node_matches, np); |
| data = match->data; |
| |
| of_node_put(np); |
| |
| if (data && data->flags & SOC_BLACKLIST) |
| return -ENODEV; |
| |
| ret = cpufreq_register_driver(&qoriq_cpufreq_driver); |
| if (!ret) |
| pr_info("Freescale QorIQ CPU frequency scaling driver\n"); |
| |
| return ret; |
| } |
| module_init(qoriq_cpufreq_init); |
| |
| static void __exit qoriq_cpufreq_exit(void) |
| { |
| cpufreq_unregister_driver(&qoriq_cpufreq_driver); |
| } |
| module_exit(qoriq_cpufreq_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>"); |
| MODULE_DESCRIPTION("cpufreq driver for Freescale QorIQ series SoCs"); |