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309 lines
6.9 KiB
309 lines
6.9 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright 2013 Freescale Semiconductor, Inc. |
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* |
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* CPU Frequency Scaling driver for Freescale QorIQ SoCs. |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/clk.h> |
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#include <linux/clk-provider.h> |
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#include <linux/cpufreq.h> |
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#include <linux/errno.h> |
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/mutex.h> |
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#include <linux/of.h> |
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#include <linux/slab.h> |
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#include <linux/smp.h> |
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#include <linux/platform_device.h> |
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/** |
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* struct cpu_data |
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* @pclk: the parent clock of cpu |
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* @table: frequency table |
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*/ |
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struct cpu_data { |
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struct clk **pclk; |
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struct cpufreq_frequency_table *table; |
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}; |
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/** |
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* struct soc_data - SoC specific data |
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* @flags: SOC_xxx |
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*/ |
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struct soc_data { |
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u32 flags; |
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}; |
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static u32 get_bus_freq(void) |
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{ |
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struct device_node *soc; |
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u32 sysfreq; |
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struct clk *pltclk; |
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int ret; |
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/* get platform freq by searching bus-frequency property */ |
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soc = of_find_node_by_type(NULL, "soc"); |
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if (soc) { |
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ret = of_property_read_u32(soc, "bus-frequency", &sysfreq); |
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of_node_put(soc); |
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if (!ret) |
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return sysfreq; |
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} |
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/* get platform freq by its clock name */ |
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pltclk = clk_get(NULL, "cg-pll0-div1"); |
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if (IS_ERR(pltclk)) { |
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pr_err("%s: can't get bus frequency %ld\n", |
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__func__, PTR_ERR(pltclk)); |
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return PTR_ERR(pltclk); |
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} |
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return clk_get_rate(pltclk); |
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} |
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static struct clk *cpu_to_clk(int cpu) |
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{ |
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struct device_node *np; |
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struct clk *clk; |
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if (!cpu_present(cpu)) |
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return NULL; |
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np = of_get_cpu_node(cpu, NULL); |
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if (!np) |
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return NULL; |
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clk = of_clk_get(np, 0); |
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of_node_put(np); |
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return clk; |
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} |
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/* traverse cpu nodes to get cpu mask of sharing clock wire */ |
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static void set_affected_cpus(struct cpufreq_policy *policy) |
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{ |
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struct cpumask *dstp = policy->cpus; |
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struct clk *clk; |
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int i; |
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for_each_present_cpu(i) { |
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clk = cpu_to_clk(i); |
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if (IS_ERR(clk)) { |
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pr_err("%s: no clock for cpu %d\n", __func__, i); |
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continue; |
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} |
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if (clk_is_match(policy->clk, clk)) |
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cpumask_set_cpu(i, dstp); |
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} |
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} |
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/* reduce the duplicated frequencies in frequency table */ |
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static void freq_table_redup(struct cpufreq_frequency_table *freq_table, |
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int count) |
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{ |
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int i, j; |
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for (i = 1; i < count; i++) { |
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for (j = 0; j < i; j++) { |
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if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID || |
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freq_table[j].frequency != |
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freq_table[i].frequency) |
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continue; |
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freq_table[i].frequency = CPUFREQ_ENTRY_INVALID; |
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break; |
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} |
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} |
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} |
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/* sort the frequencies in frequency table in descenting order */ |
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static void freq_table_sort(struct cpufreq_frequency_table *freq_table, |
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int count) |
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{ |
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int i, j, ind; |
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unsigned int freq, max_freq; |
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struct cpufreq_frequency_table table; |
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for (i = 0; i < count - 1; i++) { |
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max_freq = freq_table[i].frequency; |
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ind = i; |
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for (j = i + 1; j < count; j++) { |
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freq = freq_table[j].frequency; |
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if (freq == CPUFREQ_ENTRY_INVALID || |
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freq <= max_freq) |
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continue; |
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ind = j; |
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max_freq = freq; |
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} |
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if (ind != i) { |
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/* exchange the frequencies */ |
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table.driver_data = freq_table[i].driver_data; |
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table.frequency = freq_table[i].frequency; |
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freq_table[i].driver_data = freq_table[ind].driver_data; |
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freq_table[i].frequency = freq_table[ind].frequency; |
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freq_table[ind].driver_data = table.driver_data; |
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freq_table[ind].frequency = table.frequency; |
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} |
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} |
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} |
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static int qoriq_cpufreq_cpu_init(struct cpufreq_policy *policy) |
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{ |
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struct device_node *np; |
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int i, count; |
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u32 freq; |
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struct clk *clk; |
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const struct clk_hw *hwclk; |
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struct cpufreq_frequency_table *table; |
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struct cpu_data *data; |
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unsigned int cpu = policy->cpu; |
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u64 u64temp; |
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np = of_get_cpu_node(cpu, NULL); |
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if (!np) |
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return -ENODEV; |
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data = kzalloc(sizeof(*data), GFP_KERNEL); |
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if (!data) |
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goto err_np; |
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policy->clk = of_clk_get(np, 0); |
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if (IS_ERR(policy->clk)) { |
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pr_err("%s: no clock information\n", __func__); |
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goto err_nomem2; |
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} |
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hwclk = __clk_get_hw(policy->clk); |
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count = clk_hw_get_num_parents(hwclk); |
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data->pclk = kcalloc(count, sizeof(struct clk *), GFP_KERNEL); |
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if (!data->pclk) |
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goto err_nomem2; |
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table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL); |
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if (!table) |
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goto err_pclk; |
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for (i = 0; i < count; i++) { |
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clk = clk_hw_get_parent_by_index(hwclk, i)->clk; |
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data->pclk[i] = clk; |
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freq = clk_get_rate(clk); |
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table[i].frequency = freq / 1000; |
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table[i].driver_data = i; |
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} |
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freq_table_redup(table, count); |
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freq_table_sort(table, count); |
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table[i].frequency = CPUFREQ_TABLE_END; |
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policy->freq_table = table; |
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data->table = table; |
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/* update ->cpus if we have cluster, no harm if not */ |
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set_affected_cpus(policy); |
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policy->driver_data = data; |
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/* Minimum transition latency is 12 platform clocks */ |
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u64temp = 12ULL * NSEC_PER_SEC; |
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do_div(u64temp, get_bus_freq()); |
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policy->cpuinfo.transition_latency = u64temp + 1; |
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of_node_put(np); |
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return 0; |
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err_pclk: |
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kfree(data->pclk); |
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err_nomem2: |
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kfree(data); |
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err_np: |
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of_node_put(np); |
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return -ENODEV; |
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} |
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static int qoriq_cpufreq_cpu_exit(struct cpufreq_policy *policy) |
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{ |
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struct cpu_data *data = policy->driver_data; |
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kfree(data->pclk); |
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kfree(data->table); |
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kfree(data); |
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policy->driver_data = NULL; |
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return 0; |
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} |
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static int qoriq_cpufreq_target(struct cpufreq_policy *policy, |
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unsigned int index) |
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{ |
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struct clk *parent; |
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struct cpu_data *data = policy->driver_data; |
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parent = data->pclk[data->table[index].driver_data]; |
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return clk_set_parent(policy->clk, parent); |
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} |
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static struct cpufreq_driver qoriq_cpufreq_driver = { |
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.name = "qoriq_cpufreq", |
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.flags = CPUFREQ_CONST_LOOPS | |
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CPUFREQ_IS_COOLING_DEV, |
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.init = qoriq_cpufreq_cpu_init, |
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.exit = qoriq_cpufreq_cpu_exit, |
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.verify = cpufreq_generic_frequency_table_verify, |
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.target_index = qoriq_cpufreq_target, |
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.get = cpufreq_generic_get, |
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.attr = cpufreq_generic_attr, |
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}; |
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static const struct of_device_id qoriq_cpufreq_blacklist[] = { |
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/* e6500 cannot use cpufreq due to erratum A-008083 */ |
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{ .compatible = "fsl,b4420-clockgen", }, |
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{ .compatible = "fsl,b4860-clockgen", }, |
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{ .compatible = "fsl,t2080-clockgen", }, |
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{ .compatible = "fsl,t4240-clockgen", }, |
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{} |
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}; |
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static int qoriq_cpufreq_probe(struct platform_device *pdev) |
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{ |
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int ret; |
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struct device_node *np; |
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np = of_find_matching_node(NULL, qoriq_cpufreq_blacklist); |
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if (np) { |
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dev_info(&pdev->dev, "Disabling due to erratum A-008083"); |
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return -ENODEV; |
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} |
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ret = cpufreq_register_driver(&qoriq_cpufreq_driver); |
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if (ret) |
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return ret; |
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dev_info(&pdev->dev, "Freescale QorIQ CPU frequency scaling driver\n"); |
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return 0; |
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} |
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static int qoriq_cpufreq_remove(struct platform_device *pdev) |
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{ |
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cpufreq_unregister_driver(&qoriq_cpufreq_driver); |
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return 0; |
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} |
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static struct platform_driver qoriq_cpufreq_platform_driver = { |
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.driver = { |
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.name = "qoriq-cpufreq", |
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}, |
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.probe = qoriq_cpufreq_probe, |
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.remove = qoriq_cpufreq_remove, |
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}; |
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module_platform_driver(qoriq_cpufreq_platform_driver); |
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MODULE_ALIAS("platform:qoriq-cpufreq"); |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("Tang Yuantian <[email protected]>"); |
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MODULE_DESCRIPTION("cpufreq driver for Freescale QorIQ series SoCs");
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