| /* |
| * drivers/cpufreq/ambarella-cpufreq.c |
| * |
| * CPU Frequency Scaling for Ambarella platform |
| * |
| * Copyright (C) 2015 ST Ambarella Shanghai Co., Ltd. |
| * XianqingZheng <xqzheng@ambarella.com> |
| * |
| * This file is licensed under the terms of the GNU General Public |
| * License version 2. This program is licensed "as is" without any |
| * warranty of any kind, whether express or implied. |
| */ |
| |
| #include <linux/clk.h> |
| #include <linux/cpufreq.h> |
| #include <linux/err.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/slab.h> |
| #include <linux/types.h> |
| #include <plat/event.h> |
| #include <linux/io.h> |
| #include <plat/rct.h> |
| |
| //#define amba_cpufreq_debug //used at debug mode |
| |
| #ifdef amba_cpufreq_debug |
| #define amba_cpufreq_prt printk |
| #else |
| #define amba_cpufreq_prt(format, arg...) do {} while (0) |
| #endif |
| |
| /* Ambarella CPUFreq driver data structure */ |
| static struct { |
| struct clk *core_clk; |
| struct clk *cortex_clk; |
| unsigned int transition_latency; |
| struct cpufreq_frequency_table *cortex_clktbl; |
| struct cpufreq_frequency_table *core_clktbl; |
| } amba_cpufreq; |
| |
| static int amba_cpufreq_verify(struct cpufreq_policy *policy) |
| { |
| return cpufreq_frequency_table_verify(policy, amba_cpufreq.cortex_clktbl); |
| } |
| |
| static unsigned int amba_cpufreq_get(unsigned int cpu) |
| { |
| return clk_get_rate(amba_cpufreq.cortex_clk) / 1000; |
| } |
| |
| static int amba_cpufreq_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, unsigned int relation) |
| { |
| struct cpufreq_freqs freqs; |
| unsigned long cortex_newfreq, core_newfreq; |
| int index, ret; |
| unsigned int cur_freq; |
| |
| if(target_freq < 96000) { |
| printk("Target frequency is too low, cortex is not stable, it should be more than 96000\n"); |
| return -EINVAL; |
| } |
| |
| if (cpufreq_frequency_table_target(policy, amba_cpufreq.cortex_clktbl, |
| target_freq, relation, &index)) |
| return -EINVAL; |
| |
| freqs.old = amba_cpufreq_get(0); |
| cortex_newfreq = amba_cpufreq.cortex_clktbl[index].frequency * 1000; |
| core_newfreq = amba_cpufreq.core_clktbl[index].frequency * 1000; |
| freqs.new = cortex_newfreq / 1000; |
| |
| amba_cpufreq_prt(KERN_INFO "prepare to switch the frequency from %d KHz to %d KHz\n" |
| ,freqs.old, freqs.new); |
| |
| cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); |
| ambarella_set_event(AMBA_EVENT_PRE_CPUFREQ, NULL); |
| |
| ret = clk_set_rate(amba_cpufreq.cortex_clk, cortex_newfreq); |
| /* Get current rate after clk_set_rate, in case of failure */ |
| if (ret) { |
| pr_err("CPU Freq: cpu clk_set_rate failed: %d\n", ret); |
| freqs.new = clk_get_rate(amba_cpufreq.cortex_clk) / 1000; |
| } |
| |
| ret = clk_set_rate(amba_cpufreq.core_clk, core_newfreq); |
| /* Get current rate after clk_set_rate, in case of failure */ |
| if (ret) { |
| pr_err("CPU Freq: cpu clk_set_rate failed: %d\n", ret); |
| } |
| |
| #if (CHIP_REV == S2L) || (CHIP_REV == S3L) |
| if(amba_cpufreq.core_clktbl[index].frequency <= 96000) { |
| /*Disable IDSP/VDSP to Save Power*/ |
| amba_writel(CKEN_CLUSTER_REG, 0x540); |
| } else { |
| /*Enable IDSP/VDSP to Save Power*/ |
| amba_writel(CKEN_CLUSTER_REG, 0x3fff); |
| } |
| #endif |
| cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); |
| ambarella_set_event(AMBA_EVENT_POST_CPUFREQ, NULL); |
| |
| cur_freq = clk_get_rate(amba_cpufreq.cortex_clk) / 1000; |
| amba_cpufreq_prt(KERN_INFO "current frequency of cortex clock is:%d KHz\n", |
| cur_freq); |
| |
| |
| return ret; |
| } |
| |
| static int amba_cpufreq_init(struct cpufreq_policy *policy) |
| { |
| int ret; |
| |
| ret = cpufreq_frequency_table_cpuinfo(policy, amba_cpufreq.cortex_clktbl); |
| if (ret) { |
| pr_err("cpufreq_frequency_table_cpuinfo() failed"); |
| return ret; |
| } |
| |
| cpufreq_frequency_table_get_attr(amba_cpufreq.cortex_clktbl, policy->cpu); |
| policy->cpuinfo.transition_latency = amba_cpufreq.transition_latency; |
| policy->cur = amba_cpufreq_get(0); |
| |
| cpumask_setall(policy->cpus); |
| |
| return 0; |
| } |
| |
| static int amba_cpufreq_exit(struct cpufreq_policy *policy) |
| { |
| cpufreq_frequency_table_put_attr(policy->cpu); |
| return 0; |
| } |
| |
| static struct freq_attr *amba_cpufreq_attr[] = { |
| &cpufreq_freq_attr_scaling_available_freqs, |
| NULL, |
| }; |
| |
| static struct cpufreq_driver amba_cpufreq_driver = { |
| .name = "amba-cpufreq", |
| .flags = CPUFREQ_STICKY, |
| .verify = amba_cpufreq_verify, |
| .target = amba_cpufreq_target, |
| .get = amba_cpufreq_get, |
| .init = amba_cpufreq_init, |
| .exit = amba_cpufreq_exit, |
| .attr = amba_cpufreq_attr, |
| }; |
| |
| static int amba_cpufreq_driver_init(void) |
| { |
| struct device_node *np; |
| const struct property *prop; |
| struct cpufreq_frequency_table *cortex_freqtbl; |
| struct cpufreq_frequency_table *core_freqtbl; |
| const __be32 *val; |
| int cnt, i, ret, clk_div; |
| |
| printk("ambarella cpufreq driver init\n"); |
| np = of_find_node_by_path("/cpus"); |
| if (!np) { |
| pr_err("No cpu node found"); |
| return -ENODEV; |
| } |
| |
| ret = of_property_read_u32(np, "amb,core-div", &clk_div); |
| if (ret != 0 || !((clk_div == 1 || clk_div == 2))) { |
| /*Default is that the pll_out_core is twice gclk_core */ |
| clk_div = 2; |
| } |
| |
| if (of_property_read_u32(np, "clock-latency", |
| &amba_cpufreq.transition_latency)) |
| amba_cpufreq.transition_latency = CPUFREQ_ETERNAL; |
| |
| prop = of_find_property(np, "cpufreq_tbl", NULL); |
| if (!prop || !prop->value) { |
| pr_err("Invalid cpufreq_tbl"); |
| ret = -ENODEV; |
| goto out_put_node; |
| } |
| |
| cnt = prop->length / sizeof(u32) / 2; |
| val = prop->value; |
| |
| cortex_freqtbl = kmalloc(sizeof(*cortex_freqtbl) * (cnt + 2), GFP_KERNEL); |
| if (!cortex_freqtbl) { |
| ret = -ENOMEM; |
| goto out_put_node; |
| } |
| |
| core_freqtbl = kmalloc(sizeof(*core_freqtbl) * (cnt + 2), GFP_KERNEL); |
| if (!core_freqtbl) { |
| ret = -ENOMEM; |
| goto out_put_node; |
| } |
| |
| for (i = 0; i < cnt; i++) { |
| core_freqtbl[i].index = i; |
| /*pll_out_core = clk_div * gclk_core;*/ |
| core_freqtbl[i].frequency = be32_to_cpup(val) * clk_div; |
| |
| cortex_freqtbl[i].index = i; |
| cortex_freqtbl[i].frequency = be32_to_cpup((val + 1)); |
| val = val + 2; |
| |
| } |
| |
| cortex_freqtbl[i].index = i; |
| cortex_freqtbl[i].frequency = clk_get_rate(clk_get(NULL, "gclk_cortex")) / 1000; |
| |
| core_freqtbl[i].index = i; |
| core_freqtbl[i].frequency = clk_get_rate(clk_get(NULL, "gclk_core")) / 1000 * clk_div; |
| |
| i++; |
| cortex_freqtbl[i].index = i; |
| cortex_freqtbl[i].frequency = CPUFREQ_TABLE_END; |
| |
| core_freqtbl[i].index = i; |
| core_freqtbl[i].frequency = CPUFREQ_TABLE_END; |
| |
| amba_cpufreq.cortex_clktbl = cortex_freqtbl; |
| amba_cpufreq.core_clktbl = core_freqtbl; |
| |
| of_node_put(np); |
| |
| amba_cpufreq.core_clk = clk_get(NULL, "pll_out_core"); |
| if (IS_ERR(amba_cpufreq.core_clk)) { |
| pr_err("Unable to get core clock\n"); |
| ret = PTR_ERR(amba_cpufreq.core_clk); |
| goto out_put_mem; |
| } |
| |
| amba_cpufreq.cortex_clk = clk_get(NULL, "gclk_cortex"); |
| if (IS_ERR(amba_cpufreq.cortex_clk)) { |
| pr_err("Unable to get cotex clock\n"); |
| ret = PTR_ERR(amba_cpufreq.cortex_clk); |
| goto out_put_mem; |
| } |
| |
| ret = cpufreq_register_driver(&amba_cpufreq_driver); |
| if (!ret) |
| return 0; |
| |
| pr_err("failed register driver: %d\n", ret); |
| clk_put(amba_cpufreq.core_clk); |
| clk_put(amba_cpufreq.cortex_clk); |
| |
| out_put_mem: |
| kfree(cortex_freqtbl); |
| kfree(core_freqtbl); |
| return ret; |
| |
| out_put_node: |
| of_node_put(np); |
| return ret; |
| } |
| |
| module_init(amba_cpufreq_driver_init); |
| |
| static void __exit amba_cpufreq_driver_exit(void) |
| { |
| cpufreq_unregister_driver(&amba_cpufreq_driver); |
| if(amba_cpufreq.cortex_clktbl != NULL) { |
| kfree(amba_cpufreq.cortex_clktbl); |
| amba_cpufreq.cortex_clktbl = NULL; |
| } |
| |
| if(amba_cpufreq.core_clktbl != NULL) { |
| kfree(amba_cpufreq.core_clktbl); |
| amba_cpufreq.core_clktbl = NULL; |
| } |
| |
| } |
| module_exit(amba_cpufreq_driver_exit); |
| |
| |
| MODULE_AUTHOR("XianqingZheng <xqzheng@ambarella.com>"); |
| MODULE_DESCRIPTION("Ambarella CPUFreq driver"); |
| MODULE_LICENSE("GPL"); |