+++ /dev/null
-/*
- * CPU Frequency Scaling for Loongson 1 SoC
- *
- * Copyright (C) 2014-2016 Zhang, Keguang <keguang.zhang@gmail.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/clk-provider.h>
-#include <linux/cpu.h>
-#include <linux/cpufreq.h>
-#include <linux/delay.h>
-#include <linux/io.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-
-#include <cpufreq.h>
-#include <loongson1.h>
-
-struct ls1x_cpufreq {
- struct device *dev;
- struct clk *clk; /* CPU clk */
- struct clk *mux_clk; /* MUX of CPU clk */
- struct clk *pll_clk; /* PLL clk */
- struct clk *osc_clk; /* OSC clk */
- unsigned int max_freq;
- unsigned int min_freq;
-};
-
-static struct ls1x_cpufreq *cpufreq;
-
-static int ls1x_cpufreq_notifier(struct notifier_block *nb,
- unsigned long val, void *data)
-{
- if (val == CPUFREQ_POSTCHANGE)
- current_cpu_data.udelay_val = loops_per_jiffy;
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block ls1x_cpufreq_notifier_block = {
- .notifier_call = ls1x_cpufreq_notifier
-};
-
-static int ls1x_cpufreq_target(struct cpufreq_policy *policy,
- unsigned int index)
-{
- struct device *cpu_dev = get_cpu_device(policy->cpu);
- unsigned int old_freq, new_freq;
-
- old_freq = policy->cur;
- new_freq = policy->freq_table[index].frequency;
-
- /*
- * The procedure of reconfiguring CPU clk is as below.
- *
- * - Reparent CPU clk to OSC clk
- * - Reset CPU clock (very important)
- * - Reconfigure CPU DIV
- * - Reparent CPU clk back to CPU DIV clk
- */
-
- clk_set_parent(policy->clk, cpufreq->osc_clk);
- __raw_writel(__raw_readl(LS1X_CLK_PLL_DIV) | RST_CPU_EN | RST_CPU,
- LS1X_CLK_PLL_DIV);
- __raw_writel(__raw_readl(LS1X_CLK_PLL_DIV) & ~(RST_CPU_EN | RST_CPU),
- LS1X_CLK_PLL_DIV);
- clk_set_rate(cpufreq->mux_clk, new_freq * 1000);
- clk_set_parent(policy->clk, cpufreq->mux_clk);
- dev_dbg(cpu_dev, "%u KHz --> %u KHz\n", old_freq, new_freq);
-
- return 0;
-}
-
-static int ls1x_cpufreq_init(struct cpufreq_policy *policy)
-{
- struct device *cpu_dev = get_cpu_device(policy->cpu);
- struct cpufreq_frequency_table *freq_tbl;
- unsigned int pll_freq, freq;
- int steps, i;
-
- pll_freq = clk_get_rate(cpufreq->pll_clk) / 1000;
-
- steps = 1 << DIV_CPU_WIDTH;
- freq_tbl = kcalloc(steps, sizeof(*freq_tbl), GFP_KERNEL);
- if (!freq_tbl)
- return -ENOMEM;
-
- for (i = 0; i < (steps - 1); i++) {
- freq = pll_freq / (i + 1);
- if ((freq < cpufreq->min_freq) || (freq > cpufreq->max_freq))
- freq_tbl[i].frequency = CPUFREQ_ENTRY_INVALID;
- else
- freq_tbl[i].frequency = freq;
- dev_dbg(cpu_dev,
- "cpufreq table: index %d: frequency %d\n", i,
- freq_tbl[i].frequency);
- }
- freq_tbl[i].frequency = CPUFREQ_TABLE_END;
-
- policy->clk = cpufreq->clk;
- cpufreq_generic_init(policy, freq_tbl, 0);
-
- return 0;
-}
-
-static int ls1x_cpufreq_exit(struct cpufreq_policy *policy)
-{
- kfree(policy->freq_table);
- return 0;
-}
-
-static struct cpufreq_driver ls1x_cpufreq_driver = {
- .name = "cpufreq-ls1x",
- .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
- .verify = cpufreq_generic_frequency_table_verify,
- .target_index = ls1x_cpufreq_target,
- .get = cpufreq_generic_get,
- .init = ls1x_cpufreq_init,
- .exit = ls1x_cpufreq_exit,
- .attr = cpufreq_generic_attr,
-};
-
-static int ls1x_cpufreq_remove(struct platform_device *pdev)
-{
- cpufreq_unregister_notifier(&ls1x_cpufreq_notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
- cpufreq_unregister_driver(&ls1x_cpufreq_driver);
-
- return 0;
-}
-
-static int ls1x_cpufreq_probe(struct platform_device *pdev)
-{
- struct plat_ls1x_cpufreq *pdata = dev_get_platdata(&pdev->dev);
- struct clk *clk;
- int ret;
-
- if (!pdata || !pdata->clk_name || !pdata->osc_clk_name) {
- dev_err(&pdev->dev, "platform data missing\n");
- return -EINVAL;
- }
-
- cpufreq =
- devm_kzalloc(&pdev->dev, sizeof(struct ls1x_cpufreq), GFP_KERNEL);
- if (!cpufreq)
- return -ENOMEM;
-
- cpufreq->dev = &pdev->dev;
-
- clk = devm_clk_get(&pdev->dev, pdata->clk_name);
- if (IS_ERR(clk)) {
- dev_err(&pdev->dev, "unable to get %s clock\n",
- pdata->clk_name);
- return PTR_ERR(clk);
- }
- cpufreq->clk = clk;
-
- clk = clk_get_parent(clk);
- if (IS_ERR(clk)) {
- dev_err(&pdev->dev, "unable to get parent of %s clock\n",
- __clk_get_name(cpufreq->clk));
- return PTR_ERR(clk);
- }
- cpufreq->mux_clk = clk;
-
- clk = clk_get_parent(clk);
- if (IS_ERR(clk)) {
- dev_err(&pdev->dev, "unable to get parent of %s clock\n",
- __clk_get_name(cpufreq->mux_clk));
- return PTR_ERR(clk);
- }
- cpufreq->pll_clk = clk;
-
- clk = devm_clk_get(&pdev->dev, pdata->osc_clk_name);
- if (IS_ERR(clk)) {
- dev_err(&pdev->dev, "unable to get %s clock\n",
- pdata->osc_clk_name);
- return PTR_ERR(clk);
- }
- cpufreq->osc_clk = clk;
-
- cpufreq->max_freq = pdata->max_freq;
- cpufreq->min_freq = pdata->min_freq;
-
- ret = cpufreq_register_driver(&ls1x_cpufreq_driver);
- if (ret) {
- dev_err(&pdev->dev,
- "failed to register CPUFreq driver: %d\n", ret);
- return ret;
- }
-
- ret = cpufreq_register_notifier(&ls1x_cpufreq_notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
-
- if (ret) {
- dev_err(&pdev->dev,
- "failed to register CPUFreq notifier: %d\n",ret);
- cpufreq_unregister_driver(&ls1x_cpufreq_driver);
- }
-
- return ret;
-}
-
-static struct platform_driver ls1x_cpufreq_platdrv = {
- .probe = ls1x_cpufreq_probe,
- .remove = ls1x_cpufreq_remove,
- .driver = {
- .name = "ls1x-cpufreq",
- },
-};
-
-module_platform_driver(ls1x_cpufreq_platdrv);
-
-MODULE_ALIAS("platform:ls1x-cpufreq");
-MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>");
-MODULE_DESCRIPTION("Loongson1 CPUFreq driver");
-MODULE_LICENSE("GPL");
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