// SPDX-License-Identifier: GPL-2.0
/*
* rmobile power management support
*
* Copyright (C) 2012 Renesas Solutions Corp.
* Copyright (C) 2012 Kuninori Morimoto <[email protected]>
* Copyright (C) 2014 Glider bvba
*
* based on pm-sh7372.c
* Copyright (C) 2011 Magnus Damm
*/
#include <linux/clk/renesas.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/pm.h>
#include <linux/pm_clock.h>
#include <linux/pm_domain.h>
#include <linux/slab.h>
/* SYSC */
#define SPDCR 0x08 /* SYS Power Down Control Register */
#define SWUCR 0x14 /* SYS Wakeup Control Register */
#define PSTR 0x80 /* Power Status Register */
#define PSTR_RETRIES 100
#define PSTR_DELAY_US 10
struct rmobile_pm_domain {
struct generic_pm_domain genpd;
struct dev_power_governor *gov;
int (*suspend)(void);
void __iomem *base;
unsigned int bit_shift;
};
static inline
struct rmobile_pm_domain *to_rmobile_pd(struct generic_pm_domain *d)
{
return container_of(d, struct rmobile_pm_domain, genpd);
}
static int rmobile_pd_power_down(struct generic_pm_domain *genpd)
{
struct rmobile_pm_domain *rmobile_pd = to_rmobile_pd(genpd);
unsigned int mask = BIT(rmobile_pd->bit_shift);
u32 val;
if (rmobile_pd->suspend) {
int ret = rmobile_pd->suspend();
if (ret)
return ret;
}
if (readl(rmobile_pd->base + PSTR) & mask) {
writel(mask, rmobile_pd->base + SPDCR);
readl_poll_timeout_atomic(rmobile_pd->base + SPDCR, val,
!(val & mask), 0, PSTR_RETRIES);
}
pr_debug("%s: Power off, 0x%08x -> PSTR = 0x%08x\n", genpd->name, mask,
readl(rmobile_pd->base + PSTR));
return 0;
}
static int __rmobile_pd_power_up(struct rmobile_pm_domain *rmobile_pd)
{
unsigned int val, mask = BIT(rmobile_pd->bit_shift);
int ret = 0;
if (readl(rmobile_pd->base + PSTR) & mask)
return ret;
writel(mask, rmobile_pd->base + SWUCR);
ret = readl_poll_timeout_atomic(rmobile_pd->base + SWUCR, val,
(val & mask), PSTR_DELAY_US,
PSTR_RETRIES * PSTR_DELAY_US);
pr_debug("%s: Power on, 0x%08x -> PSTR = 0x%08x\n",
rmobile_pd->genpd.name, mask,
readl(rmobile_pd->base + PSTR));
return ret;
}
static int rmobile_pd_power_up(struct generic_pm_domain *genpd)
{
return __rmobile_pd_power_up(to_rmobile_pd(genpd));
}
static void rmobile_init_pm_domain(struct rmobile_pm_domain *rmobile_pd)
{
struct generic_pm_domain *genpd = &rmobile_pd->genpd;
struct dev_power_governor *gov = rmobile_pd->gov;
genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
genpd->attach_dev = cpg_mstp_attach_dev;
genpd->detach_dev = cpg_mstp_detach_dev;
if (!(genpd->flags & GENPD_FLAG_ALWAYS_ON)) {
genpd->power_off = rmobile_pd_power_down;
genpd->power_on = rmobile_pd_power_up;
__rmobile_pd_power_up(rmobile_pd);
}
pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
}
static int rmobile_pd_suspend_console(void)
{
/*
* Serial consoles make use of SCIF hardware located in this domain,
* hence keep the power domain on if "no_console_suspend" is set.
*/
return console_suspend_enabled ? 0 : -EBUSY;
}
enum pd_types {
PD_NORMAL,
PD_CPU,
PD_CONSOLE,
PD_DEBUG,
PD_MEMCTL,
};
#define MAX_NUM_SPECIAL_PDS 16
static struct special_pd {
struct device_node *pd;
enum pd_types type;
} special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
static unsigned int num_special_pds __initdata;
static const struct of_device_id special_ids[] __initconst = {
{ .compatible = "arm,coresight-etm3x", .data = (void *)PD_DEBUG },
{ .compatible = "renesas,dbsc-r8a73a4", .data = (void *)PD_MEMCTL, },
{ .compatible = "renesas,dbsc3-r8a7740", .data = (void *)PD_MEMCTL, },
{ .compatible = "renesas,sbsc-sh73a0", .data = (void *)PD_MEMCTL, },
{ /* sentinel */ },
};
static void __init add_special_pd(struct device_node *np, enum pd_types type)
{
unsigned int i;
struct device_node *pd;
pd = of_parse_phandle(np, "power-domains", 0);
if (!pd)
return;
for (i = 0; i < num_special_pds; i++)
if (pd == special_pds[i].pd && type == special_pds[i].type) {
of_node_put(pd);
return;
}
if (num_special_pds == ARRAY_SIZE(special_pds)) {
pr_warn("Too many special PM domains\n");
of_node_put(pd);
return;
}
pr_debug("Special PM domain %pOFn type %d for %pOF\n", pd, type, np);
special_pds[num_special_pds].pd = pd;
special_pds[num_special_pds].type = type;
num_special_pds++;
}
static void __init get_special_pds(void)
{
struct device_node *np;
const struct of_device_id *id;
/* PM domains containing CPUs */
for_each_of_cpu_node(np)
add_special_pd(np, PD_CPU);
/* PM domain containing console */
if (of_stdout)
add_special_pd(of_stdout, PD_CONSOLE);
/* PM domains containing other special devices */
for_each_matching_node_and_match(np, special_ids, &id)
add_special_pd(np, (uintptr_t)id->data);
}
static void __init put_special_pds(void)
{
unsigned int i;
for (i = 0; i < num_special_pds; i++)
of_node_put(special_pds[i].pd);
}
static enum pd_types __init pd_type(const struct device_node *pd)
{
unsigned int i;
for (i = 0; i < num_special_pds; i++)
if (pd == special_pds[i].pd)
return special_pds[i].type;
return PD_NORMAL;
}
static void __init rmobile_setup_pm_domain(struct device_node *np,
struct rmobile_pm_domain *pd)
{
const char *name = pd->genpd.name;
switch (pd_type(np)) {
case PD_CPU:
/*
* This domain contains the CPU core and therefore it should
* only be turned off if the CPU is not in use.
*/
pr_debug("PM domain %s contains CPU\n", name);
pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
break;
case PD_CONSOLE:
pr_debug("PM domain %s contains serial console\n", name);
pd->gov = &pm_domain_always_on_gov;
pd->suspend = rmobile_pd_suspend_console;
break;
case PD_DEBUG:
/*
* This domain contains the Coresight-ETM hardware block and
* therefore it should only be turned off if the debug module
* is not in use.
*/
pr_debug("PM domain %s contains Coresight-ETM\n", name);
pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
break;
case PD_MEMCTL:
/*
* This domain contains a memory-controller and therefore it
* should only be turned off if memory is not in use.
*/
pr_debug("PM domain %s contains MEMCTL\n", name);
pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
break;
case PD_NORMAL:
if (pd->bit_shift == ~0) {
/* Top-level always-on domain */
pr_debug("PM domain %s is always-on domain\n", name);
pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
}
break;
}
rmobile_init_pm_domain(pd);
}
static int __init rmobile_add_pm_domains(void __iomem *base,
struct device_node *parent,
struct generic_pm_domain *genpd_parent)
{
for_each_child_of_node_scoped(parent, np) {
struct rmobile_pm_domain *pd;
u32 idx = ~0;
if (of_property_read_u32(np, "reg", &idx)) {
/* always-on domain */
}
pd = kzalloc(sizeof(*pd), GFP_KERNEL);
if (!pd)
return -ENOMEM;
pd->genpd.name = np->name;
pd->base = base;
pd->bit_shift = idx;
rmobile_setup_pm_domain(np, pd);
if (genpd_parent)
pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
of_genpd_add_provider_simple(np, &pd->genpd);
rmobile_add_pm_domains(base, np, &pd->genpd);
}
return 0;
}
static int __init rmobile_init_pm_domains(void)
{
struct device_node *np, *pmd;
bool scanned = false;
void __iomem *base;
int ret = 0;
for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
base = of_iomap(np, 0);
if (!base) {
pr_warn("%pOF cannot map reg 0\n", np);
continue;
}
pmd = of_get_child_by_name(np, "pm-domains");
if (!pmd) {
iounmap(base);
pr_warn("%pOF lacks pm-domains node\n", np);
continue;
}
if (!scanned) {
/* Find PM domains containing special blocks */
get_special_pds();
scanned = true;
}
ret = rmobile_add_pm_domains(base, pmd, NULL);
of_node_put(pmd);
if (ret) {
of_node_put(np);
break;
}
fwnode_dev_initialized(of_fwnode_handle(np), true);
}
put_special_pds();
return ret;
}
core_initcall(rmobile_init_pm_domains);
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