// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2015 Linaro Ltd.
* Author: Pi-Cheng Chen <[email protected]>
*/
#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/regulator/consumer.h>
struct mtk_cpufreq_platform_data {
int min_volt_shift;
int max_volt_shift;
int proc_max_volt;
int sram_min_volt;
int sram_max_volt;
bool ccifreq_supported;
};
/*
* The struct mtk_cpu_dvfs_info holds necessary information for doing CPU DVFS
* on each CPU power/clock domain of Mediatek SoCs. Each CPU cluster in
* Mediatek SoCs has two voltage inputs, Vproc and Vsram. In some cases the two
* voltage inputs need to be controlled under a hardware limitation:
* 100mV < Vsram - Vproc < 200mV
*
* When scaling the clock frequency of a CPU clock domain, the clock source
* needs to be switched to another stable PLL clock temporarily until
* the original PLL becomes stable at target frequency.
*/
struct mtk_cpu_dvfs_info {
struct cpumask cpus;
struct device *cpu_dev;
struct device *cci_dev;
struct regulator *proc_reg;
struct regulator *sram_reg;
struct clk *cpu_clk;
struct clk *inter_clk;
struct list_head list_head;
int intermediate_voltage;
bool need_voltage_tracking;
int vproc_on_boot;
int pre_vproc;
/* Avoid race condition for regulators between notify and policy */
struct mutex reg_lock;
struct notifier_block opp_nb;
unsigned int opp_cpu;
unsigned long current_freq;
const struct mtk_cpufreq_platform_data *soc_data;
int vtrack_max;
bool ccifreq_bound;
};
static struct platform_device *cpufreq_pdev;
static LIST_HEAD(dvfs_info_list);
static struct mtk_cpu_dvfs_info *mtk_cpu_dvfs_info_lookup(int cpu)
{
struct mtk_cpu_dvfs_info *info;
list_for_each_entry(info, &dvfs_info_list, list_head) {
if (cpumask_test_cpu(cpu, &info->cpus))
return info;
}
return NULL;
}
static int mtk_cpufreq_voltage_tracking(struct mtk_cpu_dvfs_info *info,
int new_vproc)
{
const struct mtk_cpufreq_platform_data *soc_data = info->soc_data;
struct regulator *proc_reg = info->proc_reg;
struct regulator *sram_reg = info->sram_reg;
int pre_vproc, pre_vsram, new_vsram, vsram, vproc, ret;
int retry = info->vtrack_max;
pre_vproc = regulator_get_voltage(proc_reg);
if (pre_vproc < 0) {
dev_err(info->cpu_dev,
"invalid Vproc value: %d\n", pre_vproc);
return pre_vproc;
}
pre_vsram = regulator_get_voltage(sram_reg);
if (pre_vsram < 0) {
dev_err(info->cpu_dev, "invalid Vsram value: %d\n", pre_vsram);
return pre_vsram;
}
new_vsram = clamp(new_vproc + soc_data->min_volt_shift,
soc_data->sram_min_volt, soc_data->sram_max_volt);
do {
if (pre_vproc <= new_vproc) {
vsram = clamp(pre_vproc + soc_data->max_volt_shift,
soc_data->sram_min_volt, new_vsram);
ret = regulator_set_voltage(sram_reg, vsram,
soc_data->sram_max_volt);
if (ret)
return ret;
if (vsram == soc_data->sram_max_volt ||
new_vsram == soc_data->sram_min_volt)
vproc = new_vproc;
else
vproc = vsram - soc_data->min_volt_shift;
ret = regulator_set_voltage(proc_reg, vproc,
soc_data->proc_max_volt);
if (ret) {
regulator_set_voltage(sram_reg, pre_vsram,
soc_data->sram_max_volt);
return ret;
}
} else if (pre_vproc > new_vproc) {
vproc = max(new_vproc,
pre_vsram - soc_data->max_volt_shift);
ret = regulator_set_voltage(proc_reg, vproc,
soc_data->proc_max_volt);
if (ret)
return ret;
if (vproc == new_vproc)
vsram = new_vsram;
else
vsram = max(new_vsram,
vproc + soc_data->min_volt_shift);
ret = regulator_set_voltage(sram_reg, vsram,
soc_data->sram_max_volt);
if (ret) {
regulator_set_voltage(proc_reg, pre_vproc,
soc_data->proc_max_volt);
return ret;
}
}
pre_vproc = vproc;
pre_vsram = vsram;
if (--retry < 0) {
dev_err(info->cpu_dev,
"over loop count, failed to set voltage\n");
return -EINVAL;
}
} while (vproc != new_vproc || vsram != new_vsram);
return 0;
}
static int mtk_cpufreq_set_voltage(struct mtk_cpu_dvfs_info *info, int vproc)
{
const struct mtk_cpufreq_platform_data *soc_data = info->soc_data;
int ret;
if (info->need_voltage_tracking)
ret = mtk_cpufreq_voltage_tracking(info, vproc);
else
ret = regulator_set_voltage(info->proc_reg, vproc,
soc_data->proc_max_volt);
if (!ret)
info->pre_vproc = vproc;
return ret;
}
static bool is_ccifreq_ready(struct mtk_cpu_dvfs_info *info)
{
struct device_link *sup_link;
if (info->ccifreq_bound)
return true;
sup_link = device_link_add(info->cpu_dev, info->cci_dev,
DL_FLAG_AUTOREMOVE_CONSUMER);
if (!sup_link) {
dev_err(info->cpu_dev, "cpu%d: sup_link is NULL\n", info->opp_cpu);
return false;
}
if (sup_link->supplier->links.status != DL_DEV_DRIVER_BOUND)
return false;
info->ccifreq_bound = true;
return true;
}
static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
unsigned int index)
{
struct cpufreq_frequency_table *freq_table = policy->freq_table;
struct clk *cpu_clk = policy->clk;
struct clk *armpll = clk_get_parent(cpu_clk);
struct mtk_cpu_dvfs_info *info = policy->driver_data;
struct device *cpu_dev = info->cpu_dev;
struct dev_pm_opp *opp;
long freq_hz, pre_freq_hz;
int vproc, pre_vproc, inter_vproc, target_vproc, ret;
inter_vproc = info->intermediate_voltage;
pre_freq_hz = clk_get_rate(cpu_clk);
mutex_lock(&info->reg_lock);
if (unlikely(info->pre_vproc <= 0))
pre_vproc = regulator_get_voltage(info->proc_reg);
else
pre_vproc = info->pre_vproc;
if (pre_vproc < 0) {
dev_err(cpu_dev, "invalid Vproc value: %d\n", pre_vproc);
ret = pre_vproc;
goto out;
}
freq_hz = freq_table[index].frequency * 1000;
opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
if (IS_ERR(opp)) {
dev_err(cpu_dev, "cpu%d: failed to find OPP for %ld\n",
policy->cpu, freq_hz);
ret = PTR_ERR(opp);
goto out;
}
vproc = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);
/*
* If MediaTek cci is supported but is not ready, we will use the value
* of max(target cpu voltage, booting voltage) to prevent high freqeuncy
* low voltage crash.
*/
if (info->soc_data->ccifreq_supported && !is_ccifreq_ready(info))
vproc = max(vproc, info->vproc_on_boot);
/*
* If the new voltage or the intermediate voltage is higher than the
* current voltage, scale up voltage first.
*/
target_vproc = max(inter_vproc, vproc);
if (pre_vproc <= target_vproc) {
ret = mtk_cpufreq_set_voltage(info, target_vproc);
if (ret) {
dev_err(cpu_dev,
"cpu%d: failed to scale up voltage!\n", policy->cpu);
mtk_cpufreq_set_voltage(info, pre_vproc);
goto out;
}
}
/* Reparent the CPU clock to intermediate clock. */
ret = clk_set_parent(cpu_clk, info->inter_clk);
if (ret) {
dev_err(cpu_dev,
"cpu%d: failed to re-parent cpu clock!\n", policy->cpu);
mtk_cpufreq_set_voltage(info, pre_vproc);
goto out;
}
/* Set the original PLL to target rate. */
ret = clk_set_rate(armpll, freq_hz);
if (ret) {
dev_err(cpu_dev,
"cpu%d: failed to scale cpu clock rate!\n", policy->cpu);
clk_set_parent(cpu_clk, armpll);
mtk_cpufreq_set_voltage(info, pre_vproc);
goto out;
}
/* Set parent of CPU clock back to the original PLL. */
ret = clk_set_parent(cpu_clk, armpll);
if (ret) {
dev_err(cpu_dev,
"cpu%d: failed to re-parent cpu clock!\n", policy->cpu);
mtk_cpufreq_set_voltage(info, inter_vproc);
goto out;
}
/*
* If the new voltage is lower than the intermediate voltage or the
* original voltage, scale down to the new voltage.
*/
if (vproc < inter_vproc || vproc < pre_vproc) {
ret = mtk_cpufreq_set_voltage(info, vproc);
if (ret) {
dev_err(cpu_dev,
"cpu%d: failed to scale down voltage!\n", policy->cpu);
clk_set_parent(cpu_clk, info->inter_clk);
clk_set_rate(armpll, pre_freq_hz);
clk_set_parent(cpu_clk, armpll);
goto out;
}
}
info->current_freq = freq_hz;
out:
mutex_unlock(&info->reg_lock);
return ret;
}
static int mtk_cpufreq_opp_notifier(struct notifier_block *nb,
unsigned long event, void *data)
{
struct dev_pm_opp *opp = data;
struct dev_pm_opp *new_opp;
struct mtk_cpu_dvfs_info *info;
unsigned long freq, volt;
struct cpufreq_policy *policy;
int ret = 0;
info = container_of(nb, struct mtk_cpu_dvfs_info, opp_nb);
if (event == OPP_EVENT_ADJUST_VOLTAGE) {
freq = dev_pm_opp_get_freq(opp);
mutex_lock(&info->reg_lock);
if (info->current_freq == freq) {
volt = dev_pm_opp_get_voltage(opp);
ret = mtk_cpufreq_set_voltage(info, volt);
if (ret)
dev_err(info->cpu_dev,
"failed to scale voltage: %d\n", ret);
}
mutex_unlock(&info->reg_lock);
} else if (event == OPP_EVENT_DISABLE) {
freq = dev_pm_opp_get_freq(opp);
/* case of current opp item is disabled */
if (info->current_freq == freq) {
freq = 1;
new_opp = dev_pm_opp_find_freq_ceil(info->cpu_dev,
&freq);
if (IS_ERR(new_opp)) {
dev_err(info->cpu_dev,
"all opp items are disabled\n");
ret = PTR_ERR(new_opp);
return notifier_from_errno(ret);
}
dev_pm_opp_put(new_opp);
policy = cpufreq_cpu_get(info->opp_cpu);
if (policy) {
cpufreq_driver_target(policy, freq / 1000,
CPUFREQ_RELATION_L);
cpufreq_cpu_put(policy);
}
}
}
return notifier_from_errno(ret);
}
static struct device *of_get_cci(struct device *cpu_dev)
{
struct device_node *np;
struct platform_device *pdev;
np = of_parse_phandle(cpu_dev->of_node, "mediatek,cci", 0);
if (!np)
return ERR_PTR(-ENODEV);
pdev = of_find_device_by_node(np);
of_node_put(np);
if (!pdev)
return ERR_PTR(-ENODEV);
return &pdev->dev;
}
static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
{
struct device *cpu_dev;
struct dev_pm_opp *opp;
unsigned long rate;
int ret;
cpu_dev = get_cpu_device(cpu);
if (!cpu_dev)
return dev_err_probe(cpu_dev, -ENODEV, "failed to get cpu%d device\n", cpu);
info->cpu_dev = cpu_dev;
info->ccifreq_bound = false;
if (info->soc_data->ccifreq_supported) {
info->cci_dev = of_get_cci(info->cpu_dev);
if (IS_ERR(info->cci_dev))
return dev_err_probe(cpu_dev, PTR_ERR(info->cci_dev),
"cpu%d: failed to get cci device\n",
cpu);
}
info->cpu_clk = clk_get(cpu_dev, "cpu");
if (IS_ERR(info->cpu_clk))
return dev_err_probe(cpu_dev, PTR_ERR(info->cpu_clk),
"cpu%d: failed to get cpu clk\n", cpu);
info->inter_clk = clk_get(cpu_dev, "intermediate");
if (IS_ERR(info->inter_clk)) {
ret = PTR_ERR(info->inter_clk);
dev_err_probe(cpu_dev, ret,
"cpu%d: failed to get intermediate clk\n", cpu);
goto out_free_mux_clock;
}
info->proc_reg = regulator_get_optional(cpu_dev, "proc");
if (IS_ERR(info->proc_reg)) {
ret = PTR_ERR(info->proc_reg);
dev_err_probe(cpu_dev, ret,
"cpu%d: failed to get proc regulator\n", cpu);
goto out_free_inter_clock;
}
ret = regulator_enable(info->proc_reg);
if (ret) {
dev_err_probe(cpu_dev, ret, "cpu%d: failed to enable vproc\n", cpu);
goto out_free_proc_reg;
}
/* Both presence and absence of sram regulator are valid cases. */
info->sram_reg = regulator_get_optional(cpu_dev, "sram");
if (IS_ERR(info->sram_reg)) {
ret = PTR_ERR(info->sram_reg);
if (ret == -EPROBE_DEFER) {
dev_err_probe(cpu_dev, ret,
"cpu%d: Failed to get sram regulator\n", cpu);
goto out_disable_proc_reg;
}
info->sram_reg = NULL;
} else {
ret = regulator_enable(info->sram_reg);
if (ret) {
dev_err_probe(cpu_dev, ret, "cpu%d: failed to enable vsram\n", cpu);
goto out_free_sram_reg;
}
}
/* Get OPP-sharing information from "operating-points-v2" bindings */
ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, &info->cpus);
if (ret) {
dev_err_probe(cpu_dev, ret,
"cpu%d: failed to get OPP-sharing information\n", cpu);
goto out_disable_sram_reg;
}
ret = dev_pm_opp_of_cpumask_add_table(&info->cpus);
if (ret) {
dev_err_probe(cpu_dev, ret, "cpu%d: no OPP table\n", cpu);
goto out_disable_sram_reg;
}
ret = clk_prepare_enable(info->cpu_clk);
if (ret) {
dev_err_probe(cpu_dev, ret, "cpu%d: failed to enable cpu clk\n", cpu);
goto out_free_opp_table;
}
ret = clk_prepare_enable(info->inter_clk);
if (ret) {
dev_err_probe(cpu_dev, ret, "cpu%d: failed to enable inter clk\n", cpu);
goto out_disable_mux_clock;
}
if (info->soc_data->ccifreq_supported) {
info->vproc_on_boot = regulator_get_voltage(info->proc_reg);
if (info->vproc_on_boot < 0) {
ret = dev_err_probe(info->cpu_dev, info->vproc_on_boot,
"invalid Vproc value\n");
goto out_disable_inter_clock;
}
}
/* Search a safe voltage for intermediate frequency. */
rate = clk_get_rate(info->inter_clk);
opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
if (IS_ERR(opp)) {
ret = dev_err_probe(cpu_dev, PTR_ERR(opp),
"cpu%d: failed to get intermediate opp\n", cpu);
goto out_disable_inter_clock;
}
info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);
mutex_init(&info->reg_lock);
info->current_freq = clk_get_rate(info->cpu_clk);
info->opp_cpu = cpu;
info->opp_nb.notifier_call = mtk_cpufreq_opp_notifier;
ret = dev_pm_opp_register_notifier(cpu_dev, &info->opp_nb);
if (ret) {
dev_err_probe(cpu_dev, ret, "cpu%d: failed to register opp notifier\n", cpu);
goto out_disable_inter_clock;
}
/*
* If SRAM regulator is present, software "voltage tracking" is needed
* for this CPU power domain.
*/
info->need_voltage_tracking = (info->sram_reg != NULL);
/*
* We assume min voltage is 0 and tracking target voltage using
* min_volt_shift for each iteration.
* The vtrack_max is 3 times of expeted iteration count.
*/
info->vtrack_max = 3 * DIV_ROUND_UP(max(info->soc_data->sram_max_volt,
info->soc_data->proc_max_volt),
info->soc_data->min_volt_shift);
return 0;
out_disable_inter_clock:
clk_disable_unprepare(info->inter_clk);
out_disable_mux_clock:
clk_disable_unprepare(info->cpu_clk);
out_free_opp_table:
dev_pm_opp_of_cpumask_remove_table(&info->cpus);
out_disable_sram_reg:
if (info->sram_reg)
regulator_disable(info->sram_reg);
out_free_sram_reg:
if (info->sram_reg)
regulator_put(info->sram_reg);
out_disable_proc_reg:
regulator_disable(info->proc_reg);
out_free_proc_reg:
regulator_put(info->proc_reg);
out_free_inter_clock:
clk_put(info->inter_clk);
out_free_mux_clock:
clk_put(info->cpu_clk);
return ret;
}
static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info)
{
regulator_disable(info->proc_reg);
regulator_put(info->proc_reg);
if (info->sram_reg) {
regulator_disable(info->sram_reg);
regulator_put(info->sram_reg);
}
clk_disable_unprepare(info->cpu_clk);
clk_put(info->cpu_clk);
clk_disable_unprepare(info->inter_clk);
clk_put(info->inter_clk);
dev_pm_opp_of_cpumask_remove_table(&info->cpus);
dev_pm_opp_unregister_notifier(info->cpu_dev, &info->opp_nb);
}
static int mtk_cpufreq_init(struct cpufreq_policy *policy)
{
struct mtk_cpu_dvfs_info *info;
struct cpufreq_frequency_table *freq_table;
int ret;
info = mtk_cpu_dvfs_info_lookup(policy->cpu);
if (!info) {
pr_err("dvfs info for cpu%d is not initialized.\n",
policy->cpu);
return -EINVAL;
}
ret = dev_pm_opp_init_cpufreq_table(info->cpu_dev, &freq_table);
if (ret) {
dev_err(info->cpu_dev,
"failed to init cpufreq table for cpu%d: %d\n",
policy->cpu, ret);
return ret;
}
cpumask_copy(policy->cpus, &info->cpus);
policy->freq_table = freq_table;
policy->driver_data = info;
policy->clk = info->cpu_clk;
return 0;
}
static void mtk_cpufreq_exit(struct cpufreq_policy *policy)
{
struct mtk_cpu_dvfs_info *info = policy->driver_data;
dev_pm_opp_free_cpufreq_table(info->cpu_dev, &policy->freq_table);
}
static struct cpufreq_driver mtk_cpufreq_driver = {
.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
CPUFREQ_IS_COOLING_DEV,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = mtk_cpufreq_set_target,
.get = cpufreq_generic_get,
.init = mtk_cpufreq_init,
.exit = mtk_cpufreq_exit,
.register_em = cpufreq_register_em_with_opp,
.name = "mtk-cpufreq",
.attr = cpufreq_generic_attr,
};
static int mtk_cpufreq_probe(struct platform_device *pdev)
{
const struct mtk_cpufreq_platform_data *data;
struct mtk_cpu_dvfs_info *info, *tmp;
int cpu, ret;
data = dev_get_platdata(&pdev->dev);
if (!data)
return dev_err_probe(&pdev->dev, -ENODEV,
"failed to get mtk cpufreq platform data\n");
for_each_possible_cpu(cpu) {
info = mtk_cpu_dvfs_info_lookup(cpu);
if (info)
continue;
info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
if (!info) {
ret = dev_err_probe(&pdev->dev, -ENOMEM,
"Failed to allocate dvfs_info\n");
goto release_dvfs_info_list;
}
info->soc_data = data;
ret = mtk_cpu_dvfs_info_init(info, cpu);
if (ret)
goto release_dvfs_info_list;
list_add(&info->list_head, &dvfs_info_list);
}
ret = cpufreq_register_driver(&mtk_cpufreq_driver);
if (ret) {
dev_err_probe(&pdev->dev, ret, "failed to register mtk cpufreq driver\n");
goto release_dvfs_info_list;
}
return 0;
release_dvfs_info_list:
list_for_each_entry_safe(info, tmp, &dvfs_info_list, list_head) {
mtk_cpu_dvfs_info_release(info);
list_del(&info->list_head);
}
return ret;
}
static struct platform_driver mtk_cpufreq_platdrv = {
.driver = {
.name = "mtk-cpufreq",
},
.probe = mtk_cpufreq_probe,
};
static const struct mtk_cpufreq_platform_data mt2701_platform_data = {
.min_volt_shift = 100000,
.max_volt_shift = 200000,
.proc_max_volt = 1150000,
.sram_min_volt = 0,
.sram_max_volt = 1150000,
.ccifreq_supported = false,
};
static const struct mtk_cpufreq_platform_data mt7622_platform_data = {
.min_volt_shift = 100000,
.max_volt_shift = 200000,
.proc_max_volt = 1350000,
.sram_min_volt = 0,
.sram_max_volt = 1350000,
.ccifreq_supported = false,
};
static const struct mtk_cpufreq_platform_data mt7623_platform_data = {
.min_volt_shift = 100000,
.max_volt_shift = 200000,
.proc_max_volt = 1300000,
.ccifreq_supported = false,
};
static const struct mtk_cpufreq_platform_data mt7988_platform_data = {
.min_volt_shift = 100000,
.max_volt_shift = 200000,
.proc_max_volt = 900000,
.sram_min_volt = 0,
.sram_max_volt = 1150000,
.ccifreq_supported = true,
};
static const struct mtk_cpufreq_platform_data mt8183_platform_data = {
.min_volt_shift = 100000,
.max_volt_shift = 200000,
.proc_max_volt = 1150000,
.sram_min_volt = 0,
.sram_max_volt = 1150000,
.ccifreq_supported = true,
};
static const struct mtk_cpufreq_platform_data mt8186_platform_data = {
.min_volt_shift = 100000,
.max_volt_shift = 250000,
.proc_max_volt = 1118750,
.sram_min_volt = 850000,
.sram_max_volt = 1118750,
.ccifreq_supported = true,
};
static const struct mtk_cpufreq_platform_data mt8516_platform_data = {
.min_volt_shift = 100000,
.max_volt_shift = 200000,
.proc_max_volt = 1310000,
.sram_min_volt = 0,
.sram_max_volt = 1310000,
.ccifreq_supported = false,
};
/* List of machines supported by this driver */
static const struct of_device_id mtk_cpufreq_machines[] __initconst __maybe_unused = {
{ .compatible = "mediatek,mt2701", .data = &mt2701_platform_data },
{ .compatible = "mediatek,mt2712", .data = &mt2701_platform_data },
{ .compatible = "mediatek,mt7622", .data = &mt7622_platform_data },
{ .compatible = "mediatek,mt7623", .data = &mt7623_platform_data },
{ .compatible = "mediatek,mt7988a", .data = &mt7988_platform_data },
{ .compatible = "mediatek,mt8167", .data = &mt8516_platform_data },
{ .compatible = "mediatek,mt817x", .data = &mt2701_platform_data },
{ .compatible = "mediatek,mt8173", .data = &mt2701_platform_data },
{ .compatible = "mediatek,mt8176", .data = &mt2701_platform_data },
{ .compatible = "mediatek,mt8183", .data = &mt8183_platform_data },
{ .compatible = "mediatek,mt8186", .data = &mt8186_platform_data },
{ .compatible = "mediatek,mt8365", .data = &mt2701_platform_data },
{ .compatible = "mediatek,mt8516", .data = &mt8516_platform_data },
{ }
};
MODULE_DEVICE_TABLE(of, mtk_cpufreq_machines);
static int __init mtk_cpufreq_driver_init(void)
{
struct device_node *np;
const struct of_device_id *match;
const struct mtk_cpufreq_platform_data *data;
int err;
np = of_find_node_by_path("/");
if (!np)
return -ENODEV;
match = of_match_node(mtk_cpufreq_machines, np);
of_node_put(np);
if (!match) {
pr_debug("Machine is not compatible with mtk-cpufreq\n");
return -ENODEV;
}
data = match->data;
err = platform_driver_register(&mtk_cpufreq_platdrv);
if (err)
return err;
/*
* Since there's no place to hold device registration code and no
* device tree based way to match cpufreq driver yet, both the driver
* and the device registration codes are put here to handle defer
* probing.
*/
cpufreq_pdev = platform_device_register_data(NULL, "mtk-cpufreq", -1,
data, sizeof(*data));
if (IS_ERR(cpufreq_pdev)) {
pr_err("failed to register mtk-cpufreq platform device\n");
platform_driver_unregister(&mtk_cpufreq_platdrv);
return PTR_ERR(cpufreq_pdev);
}
return 0;
}
module_init(mtk_cpufreq_driver_init)
static void __exit mtk_cpufreq_driver_exit(void)
{
platform_device_unregister(cpufreq_pdev);
platform_driver_unregister(&mtk_cpufreq_platdrv);
}
module_exit(mtk_cpufreq_driver_exit)
MODULE_DESCRIPTION("MediaTek CPUFreq driver");
MODULE_AUTHOR("Pi-Cheng Chen <[email protected]>");
MODULE_LICENSE("GPL v2");
Codebase Browser
linux