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soc: renesas: rcar-sysc: Add DT support for SYSC PM domains

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Populate the SYSC PM domains from DT, based on the presence of a device
node for the System Controller. The actual power area hiearchy, and
features of specific areas are obtained from tables in the C code.

The SYSCIER and SYSCIMR register values are derived from the power areas
present, which will help to get rid of the hardcoded values in R-Car H1
and R-Car Gen2 platform code later.

Initialization is done from an early_initcall(), to make sure the PM
Domains are initialized before secondary CPU bringup.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
This commit is contained in:
Geert Uytterhoeven 2016-04-20 14:02:38 +02:00 committed by Simon Horman
parent 68667cebfc
commit dcc09fd143
2 changed files with 254 additions and 1 deletions
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202
drivers/soc/renesas/rcar-sysc.c
View file

@ -2,6 +2,7 @@
* R-Car SYSC Power management support
*
* Copyright (C) 2014 Magnus Damm
* Copyright (C) 2015-2016 Glider bvba
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
@ -11,10 +12,15 @@
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/mm.h>
#include <linux/of_address.h>
#include <linux/pm_domain.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/soc/renesas/rcar-sysc.h>
#include "rcar-sysc.h"
/* SYSC Common */
#define SYSCSR 0x00 /* SYSC Status Register */
#define SYSCISR 0x04 /* Interrupt Status Register */
@ -29,7 +35,8 @@
/*
* Power Control Register Offsets inside the register block for each domain
* Note: The "CR" registers for ARM cores exist on H1 only
* Use WFI to power off, CPG/APMU to resume ARM cores on R-Car Gen2
* Use WFI to power off, CPG/APMU to resume ARM cores on R-Car Gen2
* Use PSCI on R-Car Gen3
*/
#define PWRSR_OFFS 0x00 /* Power Status Register */
#define PWROFFCR_OFFS 0x04 /* Power Shutoff Control Register */
@ -48,6 +55,8 @@
#define SYSCISR_RETRIES 1000
#define SYSCISR_DELAY_US 1
#define RCAR_PD_ALWAYS_ON 32 /* Always-on power area */
static void __iomem *rcar_sysc_base;
static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
@ -162,3 +171,194 @@ void __iomem *rcar_sysc_init(phys_addr_t base)
return rcar_sysc_base;
}
struct rcar_sysc_pd {
struct generic_pm_domain genpd;
struct rcar_sysc_ch ch;
unsigned int flags;
char name[0];
};
static inline struct rcar_sysc_pd *to_rcar_pd(struct generic_pm_domain *d)
{
return container_of(d, struct rcar_sysc_pd, genpd);
}
static int rcar_sysc_pd_power_off(struct generic_pm_domain *genpd)
{
struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
pr_debug("%s: %s\n", __func__, genpd->name);
if (pd->flags & PD_NO_CR) {
pr_debug("%s: Cannot control %s\n", __func__, genpd->name);
return -EBUSY;
}
if (pd->flags & PD_BUSY) {
pr_debug("%s: %s busy\n", __func__, genpd->name);
return -EBUSY;
}
return rcar_sysc_power_down(&pd->ch);
}
static int rcar_sysc_pd_power_on(struct generic_pm_domain *genpd)
{
struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
pr_debug("%s: %s\n", __func__, genpd->name);
if (pd->flags & PD_NO_CR) {
pr_debug("%s: Cannot control %s\n", __func__, genpd->name);
return 0;
}
return rcar_sysc_power_up(&pd->ch);
}
static void __init rcar_sysc_pd_setup(struct rcar_sysc_pd *pd)
{
struct generic_pm_domain *genpd = &pd->genpd;
const char *name = pd->genpd.name;
struct dev_power_governor *gov = &simple_qos_governor;
if (pd->flags & PD_CPU) {
/*
* This domain contains a CPU core and therefore it should
* only be turned off if the CPU is not in use.
*/
pr_debug("PM domain %s contains %s\n", name, "CPU");
pd->flags |= PD_BUSY;
gov = &pm_domain_always_on_gov;
} else if (pd->flags & PD_SCU) {
/*
* This domain contains an SCU and cache-controller, and
* therefore it should only be turned off if the CPU cores are
* not in use.
*/
pr_debug("PM domain %s contains %s\n", name, "SCU");
pd->flags |= PD_BUSY;
gov = &pm_domain_always_on_gov;
} else if (pd->flags & PD_NO_CR) {
/*
* This domain cannot be turned off.
*/
pd->flags |= PD_BUSY;
gov = &pm_domain_always_on_gov;
}
genpd->power_off = rcar_sysc_pd_power_off;
genpd->power_on = rcar_sysc_pd_power_on;
if (pd->flags & (PD_CPU | PD_NO_CR)) {
/* Skip CPUs (handled by SMP code) and areas without control */
pr_debug("%s: Not touching %s\n", __func__, genpd->name);
goto finalize;
}
if (!rcar_sysc_power_is_off(&pd->ch)) {
pr_debug("%s: %s is already powered\n", __func__, genpd->name);
goto finalize;
}
rcar_sysc_power_up(&pd->ch);
finalize:
pm_genpd_init(genpd, gov, false);
}
static const struct of_device_id rcar_sysc_matches[] = {
{ /* sentinel */ }
};
struct rcar_pm_domains {
struct genpd_onecell_data onecell_data;
struct generic_pm_domain *domains[RCAR_PD_ALWAYS_ON + 1];
};
static int __init rcar_sysc_pd_init(void)
{
const struct rcar_sysc_info *info;
const struct of_device_id *match;
struct rcar_pm_domains *domains;
struct device_node *np;
u32 syscier, syscimr;
void __iomem *base;
unsigned int i;
int error;
np = of_find_matching_node_and_match(NULL, rcar_sysc_matches, &match);
if (!np)
return -ENODEV;
info = match->data;
base = of_iomap(np, 0);
if (!base) {
pr_warn("%s: Cannot map regs\n", np->full_name);
error = -ENOMEM;
goto out_put;
}
rcar_sysc_base = base;
domains = kzalloc(sizeof(*domains), GFP_KERNEL);
if (!domains) {
error = -ENOMEM;
goto out_put;
}
domains->onecell_data.domains = domains->domains;
domains->onecell_data.num_domains = ARRAY_SIZE(domains->domains);
for (i = 0, syscier = 0; i < info->num_areas; i++)
syscier |= BIT(info->areas[i].isr_bit);
/*
* Mask all interrupt sources to prevent the CPU from receiving them.
* Make sure not to clear reserved bits that were set before.
*/
syscimr = ioread32(base + SYSCIMR);
syscimr |= syscier;
pr_debug("%s: syscimr = 0x%08x\n", np->full_name, syscimr);
iowrite32(syscimr, base + SYSCIMR);
/*
* SYSC needs all interrupt sources enabled to control power.
*/
pr_debug("%s: syscier = 0x%08x\n", np->full_name, syscier);
iowrite32(syscier, base + SYSCIER);
for (i = 0; i < info->num_areas; i++) {
const struct rcar_sysc_area *area = &info->areas[i];
struct rcar_sysc_pd *pd;
pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
if (!pd) {
error = -ENOMEM;
goto out_put;
}
strcpy(pd->name, area->name);
pd->genpd.name = pd->name;
pd->ch.chan_offs = area->chan_offs;
pd->ch.chan_bit = area->chan_bit;
pd->ch.isr_bit = area->isr_bit;
pd->flags = area->flags;
rcar_sysc_pd_setup(pd);
if (area->parent >= 0)
pm_genpd_add_subdomain(domains->domains[area->parent],
&pd->genpd);
domains->domains[area->isr_bit] = &pd->genpd;
}
of_genpd_add_provider_onecell(np, &domains->onecell_data);
out_put:
of_node_put(np);
return error;
}
early_initcall(rcar_sysc_pd_init);

53
drivers/soc/renesas/rcar-sysc.h Normal file
View file

@ -0,0 +1,53 @@
/*
* Renesas R-Car System Controller
*
* Copyright (C) 2016 Glider bvba
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*/
#ifndef __SOC_RENESAS_RCAR_SYSC_H__
#define __SOC_RENESAS_RCAR_SYSC_H__
#include <linux/types.h>
/*
* Power Domain flags
*/
#define PD_CPU BIT(0) /* Area contains main CPU core */
#define PD_SCU BIT(1) /* Area contains SCU and L2 cache */
#define PD_NO_CR BIT(2) /* Area lacks PWR{ON,OFF}CR registers */
#define PD_BUSY BIT(3) /* Busy, for internal use only */
#define PD_CPU_CR PD_CPU /* CPU area has CR (R-Car H1) */
#define PD_CPU_NOCR PD_CPU | PD_NO_CR /* CPU area lacks CR (R-Car Gen2/3) */
#define PD_ALWAYS_ON PD_NO_CR /* Always-on area */
/*
* Description of a Power Area
*/
struct rcar_sysc_area {
const char *name;
u16 chan_offs; /* Offset of PWRSR register for this area */
u8 chan_bit; /* Bit in PWR* (except for PWRUP in PWRSR) */
u8 isr_bit; /* Bit in SYSCI*R */
int parent; /* -1 if none */
unsigned int flags; /* See PD_* */
};
/*
* SoC-specific Power Area Description
*/
struct rcar_sysc_info {
const struct rcar_sysc_area *areas;
unsigned int num_areas;
};
#endif /* __SOC_RENESAS_RCAR_SYSC_H__ */