linux-stable/drivers/cpufreq/apple-soc-cpufreq.c
Dan Carpenter f43523620f cpufreq: apple-soc: Fix an IS_ERR() vs NULL check
The of_iomap() function returns NULL if it fails.  It never returns
error pointers.  Fix the check accordingly.

Fixes: 6286bbb405 ("cpufreq: apple-soc: Add new driver to control Apple SoC CPU P-states")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Eric Curtin <ecurtin@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-03-01 19:34:54 +01:00

353 lines
9.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Apple SoC CPU cluster performance state driver
*
* Copyright The Asahi Linux Contributors
*
* Based on scpi-cpufreq.c
*/
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/pm_opp.h>
#include <linux/slab.h>
#define APPLE_DVFS_CMD 0x20
#define APPLE_DVFS_CMD_BUSY BIT(31)
#define APPLE_DVFS_CMD_SET BIT(25)
#define APPLE_DVFS_CMD_PS2 GENMASK(16, 12)
#define APPLE_DVFS_CMD_PS1 GENMASK(4, 0)
/* Same timebase as CPU counter (24MHz) */
#define APPLE_DVFS_LAST_CHG_TIME 0x38
/*
* Apple ran out of bits and had to shift this in T8112...
*/
#define APPLE_DVFS_STATUS 0x50
#define APPLE_DVFS_STATUS_CUR_PS_T8103 GENMASK(7, 4)
#define APPLE_DVFS_STATUS_CUR_PS_SHIFT_T8103 4
#define APPLE_DVFS_STATUS_TGT_PS_T8103 GENMASK(3, 0)
#define APPLE_DVFS_STATUS_CUR_PS_T8112 GENMASK(9, 5)
#define APPLE_DVFS_STATUS_CUR_PS_SHIFT_T8112 5
#define APPLE_DVFS_STATUS_TGT_PS_T8112 GENMASK(4, 0)
/*
* Div is +1, base clock is 12MHz on existing SoCs.
* For documentation purposes. We use the OPP table to
* get the frequency.
*/
#define APPLE_DVFS_PLL_STATUS 0xc0
#define APPLE_DVFS_PLL_FACTOR 0xc8
#define APPLE_DVFS_PLL_FACTOR_MULT GENMASK(31, 16)
#define APPLE_DVFS_PLL_FACTOR_DIV GENMASK(15, 0)
#define APPLE_DVFS_TRANSITION_TIMEOUT 100
struct apple_soc_cpufreq_info {
u64 max_pstate;
u64 cur_pstate_mask;
u64 cur_pstate_shift;
};
struct apple_cpu_priv {
struct device *cpu_dev;
void __iomem *reg_base;
const struct apple_soc_cpufreq_info *info;
};
static struct cpufreq_driver apple_soc_cpufreq_driver;
static const struct apple_soc_cpufreq_info soc_t8103_info = {
.max_pstate = 15,
.cur_pstate_mask = APPLE_DVFS_STATUS_CUR_PS_T8103,
.cur_pstate_shift = APPLE_DVFS_STATUS_CUR_PS_SHIFT_T8103,
};
static const struct apple_soc_cpufreq_info soc_t8112_info = {
.max_pstate = 31,
.cur_pstate_mask = APPLE_DVFS_STATUS_CUR_PS_T8112,
.cur_pstate_shift = APPLE_DVFS_STATUS_CUR_PS_SHIFT_T8112,
};
static const struct apple_soc_cpufreq_info soc_default_info = {
.max_pstate = 15,
.cur_pstate_mask = 0, /* fallback */
};
static const struct of_device_id apple_soc_cpufreq_of_match[] = {
{
.compatible = "apple,t8103-cluster-cpufreq",
.data = &soc_t8103_info,
},
{
.compatible = "apple,t8112-cluster-cpufreq",
.data = &soc_t8112_info,
},
{
.compatible = "apple,cluster-cpufreq",
.data = &soc_default_info,
},
{}
};
static unsigned int apple_soc_cpufreq_get_rate(unsigned int cpu)
{
struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
struct apple_cpu_priv *priv = policy->driver_data;
struct cpufreq_frequency_table *p;
unsigned int pstate;
if (priv->info->cur_pstate_mask) {
u64 reg = readq_relaxed(priv->reg_base + APPLE_DVFS_STATUS);
pstate = (reg & priv->info->cur_pstate_mask) >> priv->info->cur_pstate_shift;
} else {
/*
* For the fallback case we might not know the layout of DVFS_STATUS,
* so just use the command register value (which ignores boost limitations).
*/
u64 reg = readq_relaxed(priv->reg_base + APPLE_DVFS_CMD);
pstate = FIELD_GET(APPLE_DVFS_CMD_PS1, reg);
}
cpufreq_for_each_valid_entry(p, policy->freq_table)
if (p->driver_data == pstate)
return p->frequency;
dev_err(priv->cpu_dev, "could not find frequency for pstate %d\n",
pstate);
return 0;
}
static int apple_soc_cpufreq_set_target(struct cpufreq_policy *policy,
unsigned int index)
{
struct apple_cpu_priv *priv = policy->driver_data;
unsigned int pstate = policy->freq_table[index].driver_data;
u64 reg;
/* Fallback for newer SoCs */
if (index > priv->info->max_pstate)
index = priv->info->max_pstate;
if (readq_poll_timeout_atomic(priv->reg_base + APPLE_DVFS_CMD, reg,
!(reg & APPLE_DVFS_CMD_BUSY), 2,
APPLE_DVFS_TRANSITION_TIMEOUT)) {
return -EIO;
}
reg &= ~(APPLE_DVFS_CMD_PS1 | APPLE_DVFS_CMD_PS2);
reg |= FIELD_PREP(APPLE_DVFS_CMD_PS1, pstate);
reg |= FIELD_PREP(APPLE_DVFS_CMD_PS2, pstate);
reg |= APPLE_DVFS_CMD_SET;
writeq_relaxed(reg, priv->reg_base + APPLE_DVFS_CMD);
return 0;
}
static unsigned int apple_soc_cpufreq_fast_switch(struct cpufreq_policy *policy,
unsigned int target_freq)
{
if (apple_soc_cpufreq_set_target(policy, policy->cached_resolved_idx) < 0)
return 0;
return policy->freq_table[policy->cached_resolved_idx].frequency;
}
static int apple_soc_cpufreq_find_cluster(struct cpufreq_policy *policy,
void __iomem **reg_base,
const struct apple_soc_cpufreq_info **info)
{
struct of_phandle_args args;
const struct of_device_id *match;
int ret = 0;
ret = of_perf_domain_get_sharing_cpumask(policy->cpu, "performance-domains",
"#performance-domain-cells",
policy->cpus, &args);
if (ret < 0)
return ret;
match = of_match_node(apple_soc_cpufreq_of_match, args.np);
of_node_put(args.np);
if (!match)
return -ENODEV;
*info = match->data;
*reg_base = of_iomap(args.np, 0);
if (!*reg_base)
return -ENOMEM;
return 0;
}
static struct freq_attr *apple_soc_cpufreq_hw_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL, /* Filled in below if boost is enabled */
NULL,
};
static int apple_soc_cpufreq_init(struct cpufreq_policy *policy)
{
int ret, i;
unsigned int transition_latency;
void __iomem *reg_base;
struct device *cpu_dev;
struct apple_cpu_priv *priv;
const struct apple_soc_cpufreq_info *info;
struct cpufreq_frequency_table *freq_table;
cpu_dev = get_cpu_device(policy->cpu);
if (!cpu_dev) {
pr_err("failed to get cpu%d device\n", policy->cpu);
return -ENODEV;
}
ret = dev_pm_opp_of_add_table(cpu_dev);
if (ret < 0) {
dev_err(cpu_dev, "%s: failed to add OPP table: %d\n", __func__, ret);
return ret;
}
ret = apple_soc_cpufreq_find_cluster(policy, &reg_base, &info);
if (ret) {
dev_err(cpu_dev, "%s: failed to get cluster info: %d\n", __func__, ret);
return ret;
}
ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
if (ret) {
dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", __func__, ret);
goto out_iounmap;
}
ret = dev_pm_opp_get_opp_count(cpu_dev);
if (ret <= 0) {
dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n");
ret = -EPROBE_DEFER;
goto out_free_opp;
}
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv) {
ret = -ENOMEM;
goto out_free_opp;
}
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
if (ret) {
dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
goto out_free_priv;
}
/* Get OPP levels (p-state indexes) and stash them in driver_data */
for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
unsigned long rate = freq_table[i].frequency * 1000 + 999;
struct dev_pm_opp *opp = dev_pm_opp_find_freq_floor(cpu_dev, &rate);
if (IS_ERR(opp)) {
ret = PTR_ERR(opp);
goto out_free_cpufreq_table;
}
freq_table[i].driver_data = dev_pm_opp_get_level(opp);
dev_pm_opp_put(opp);
}
priv->cpu_dev = cpu_dev;
priv->reg_base = reg_base;
priv->info = info;
policy->driver_data = priv;
policy->freq_table = freq_table;
transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
if (!transition_latency)
transition_latency = CPUFREQ_ETERNAL;
policy->cpuinfo.transition_latency = transition_latency;
policy->dvfs_possible_from_any_cpu = true;
policy->fast_switch_possible = true;
policy->suspend_freq = freq_table[0].frequency;
if (policy_has_boost_freq(policy)) {
ret = cpufreq_enable_boost_support();
if (ret) {
dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);
} else {
apple_soc_cpufreq_hw_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
apple_soc_cpufreq_driver.boost_enabled = true;
}
}
return 0;
out_free_cpufreq_table:
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
out_free_priv:
kfree(priv);
out_free_opp:
dev_pm_opp_remove_all_dynamic(cpu_dev);
out_iounmap:
iounmap(reg_base);
return ret;
}
static int apple_soc_cpufreq_exit(struct cpufreq_policy *policy)
{
struct apple_cpu_priv *priv = policy->driver_data;
dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
dev_pm_opp_remove_all_dynamic(priv->cpu_dev);
iounmap(priv->reg_base);
kfree(priv);
return 0;
}
static struct cpufreq_driver apple_soc_cpufreq_driver = {
.name = "apple-cpufreq",
.flags = CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
CPUFREQ_NEED_INITIAL_FREQ_CHECK | CPUFREQ_IS_COOLING_DEV,
.verify = cpufreq_generic_frequency_table_verify,
.get = apple_soc_cpufreq_get_rate,
.init = apple_soc_cpufreq_init,
.exit = apple_soc_cpufreq_exit,
.target_index = apple_soc_cpufreq_set_target,
.fast_switch = apple_soc_cpufreq_fast_switch,
.register_em = cpufreq_register_em_with_opp,
.attr = apple_soc_cpufreq_hw_attr,
.suspend = cpufreq_generic_suspend,
};
static int __init apple_soc_cpufreq_module_init(void)
{
if (!of_machine_is_compatible("apple,arm-platform"))
return -ENODEV;
return cpufreq_register_driver(&apple_soc_cpufreq_driver);
}
module_init(apple_soc_cpufreq_module_init);
static void __exit apple_soc_cpufreq_module_exit(void)
{
cpufreq_unregister_driver(&apple_soc_cpufreq_driver);
}
module_exit(apple_soc_cpufreq_module_exit);
MODULE_DEVICE_TABLE(of, apple_soc_cpufreq_of_match);
MODULE_AUTHOR("Hector Martin <marcan@marcan.st>");
MODULE_DESCRIPTION("Apple SoC CPU cluster DVFS driver");
MODULE_LICENSE("GPL");