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- /*
- * 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/cpufreq.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>
- #if !defined(CONFIG_ARM)
- #include <asm/smp.h> /* for get_hard_smp_processor_id() in UP configs */
- #endif
- /**
- * struct cpu_data
- * @pclk: the parent clock of cpu
- * @table: frequency table
- */
- struct cpu_data {
- struct clk **pclk;
- struct cpufreq_frequency_table *table;
- };
- /**
- * struct soc_data - SoC specific data
- * @freq_mask: mask the disallowed frequencies
- * @flag: unique flags
- */
- struct soc_data {
- u32 freq_mask[4];
- u32 flag;
- };
- #define FREQ_MASK 1
- /* see hardware specification for the allowed frqeuencies */
- static const struct soc_data sdata[] = {
- { /* used by p2041 and p3041 */
- .freq_mask = {0x8, 0x8, 0x2, 0x2},
- .flag = FREQ_MASK,
- },
- { /* used by p5020 */
- .freq_mask = {0x8, 0x2},
- .flag = FREQ_MASK,
- },
- { /* used by p4080, p5040 */
- .freq_mask = {0},
- .flag = 0,
- },
- };
- /*
- * the minimum allowed core frequency, in Hz
- * for chassis v1.0, >= platform frequency
- * for chassis v2.0, >= platform frequency / 2
- */
- static u32 min_cpufreq;
- static const u32 *fmask;
- #if defined(CONFIG_ARM)
- static int get_cpu_physical_id(int cpu)
- {
- return topology_core_id(cpu);
- }
- #else
- static int get_cpu_physical_id(int cpu)
- {
- return get_hard_smp_processor_id(cpu);
- }
- #endif
- 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 device_node *cpu_to_clk_node(int cpu)
- {
- struct device_node *np, *clk_np;
- if (!cpu_present(cpu))
- return NULL;
- np = of_get_cpu_node(cpu, NULL);
- if (!np)
- return NULL;
- clk_np = of_parse_phandle(np, "clocks", 0);
- if (!clk_np)
- return NULL;
- of_node_put(np);
- return clk_np;
- }
- /* traverse cpu nodes to get cpu mask of sharing clock wire */
- static void set_affected_cpus(struct cpufreq_policy *policy)
- {
- struct device_node *np, *clk_np;
- struct cpumask *dstp = policy->cpus;
- int i;
- np = cpu_to_clk_node(policy->cpu);
- if (!np)
- return;
- for_each_present_cpu(i) {
- clk_np = cpu_to_clk_node(i);
- if (!clk_np)
- continue;
- if (clk_np == np)
- cpumask_set_cpu(i, dstp);
- of_node_put(clk_np);
- }
- of_node_put(np);
- }
- /* 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, *pnode;
- int i, count, ret;
- u32 freq, mask;
- struct clk *clk;
- 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;
- }
- pnode = of_parse_phandle(np, "clocks", 0);
- if (!pnode) {
- pr_err("%s: could not get clock information\n", __func__);
- goto err_nomem2;
- }
- count = of_property_count_strings(pnode, "clock-names");
- data->pclk = kcalloc(count, sizeof(struct clk *), GFP_KERNEL);
- if (!data->pclk) {
- pr_err("%s: no memory\n", __func__);
- goto err_node;
- }
- table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
- if (!table) {
- pr_err("%s: no memory\n", __func__);
- goto err_pclk;
- }
- if (fmask)
- mask = fmask[get_cpu_physical_id(cpu)];
- else
- mask = 0x0;
- for (i = 0; i < count; i++) {
- clk = of_clk_get(pnode, i);
- data->pclk[i] = clk;
- freq = clk_get_rate(clk);
- /*
- * the clock is valid if its frequency is not masked
- * and large than minimum allowed frequency.
- */
- if (freq < min_cpufreq || (mask & (1 << i)))
- table[i].frequency = CPUFREQ_ENTRY_INVALID;
- else
- 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);
- of_node_put(pnode);
- return 0;
- err_nomem1:
- kfree(table);
- err_pclk:
- kfree(data->pclk);
- err_node:
- of_node_put(pnode);
- err_nomem2:
- policy->driver_data = NULL;
- kfree(data);
- err_np:
- of_node_put(np);
- return -ENODEV;
- }
- static int __exit qoriq_cpufreq_cpu_exit(struct cpufreq_policy *policy)
- {
- struct cpu_data *data = policy->driver_data;
- 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 struct cpufreq_driver qoriq_cpufreq_driver = {
- .name = "qoriq_cpufreq",
- .flags = CPUFREQ_CONST_LOOPS,
- .init = qoriq_cpufreq_cpu_init,
- .exit = __exit_p(qoriq_cpufreq_cpu_exit),
- .verify = cpufreq_generic_frequency_table_verify,
- .target_index = qoriq_cpufreq_target,
- .get = cpufreq_generic_get,
- .attr = cpufreq_generic_attr,
- };
- static const struct of_device_id node_matches[] __initconst = {
- { .compatible = "fsl,p2041-clockgen", .data = &sdata[0], },
- { .compatible = "fsl,p3041-clockgen", .data = &sdata[0], },
- { .compatible = "fsl,p5020-clockgen", .data = &sdata[1], },
- { .compatible = "fsl,p4080-clockgen", .data = &sdata[2], },
- { .compatible = "fsl,p5040-clockgen", .data = &sdata[2], },
- { .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;
- if (data) {
- if (data->flag)
- fmask = data->freq_mask;
- min_cpufreq = get_bus_freq();
- } else {
- min_cpufreq = get_bus_freq() / 2;
- }
- of_node_put(np);
- 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");
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