mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 18:30:06 +00:00
![Kelvin Cheung](/assets/img/avatar_default.png)
This patch replaces goto out with return in ls1x_cpufreq_probe(). Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: linux-pm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13056/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
222 lines
5.5 KiB
C
222 lines
5.5 KiB
C
/*
|
|
* 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/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, ret;
|
|
|
|
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;
|
|
ret = cpufreq_generic_init(policy, freq_tbl, 0);
|
|
if (ret)
|
|
kfree(freq_tbl);
|
|
|
|
return ret;
|
|
}
|
|
|
|
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_STICKY | 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_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>");
|
|
MODULE_DESCRIPTION("Loongson1 CPUFreq driver");
|
|
MODULE_LICENSE("GPL");
|