[PATCH v6 03/11] soc: renesas: rcar-sysc: Add DT support for SYSC PM domains

Ulf Hansson ulf.hansson at linaro.org
Fri Apr 22 00:21:46 PDT 2016


On 20 April 2016 at 14:02, Geert Uytterhoeven <geert+renesas at glider.be> wrote:
> 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 at glider.be>

Reviewed-by: Ulf Hansson <ulf.hansson at linaro.org>

Kind regards
Uffe

> ---
> v6:
>   - Drop unneeded genpd->dev_ops.active_wakeup callback,
>   - Move call to pm_genpd_init() after all local initialization,
>
> v5:
>   - Mask SYSC interrupts sources before enabling them (doesn't matter
>     much as they're disabled at the GIC level anyway),
>   - Re-add explicit "always-on" power area instead of aliasing the SoC's
>     Clock Domain,
>   - Merge the two initialization phases again,
>
> v4:
>   - Make sure not to clear reserved SYSCIMR bits that were set before,
>   - Make the always-on power area implicit and always present, and an
>     alias of the existing SoC's Clock Domain. This makes the number of
>     power areas a compile-time constant, and allows to drop PD_ALWAYS_ON
>     and some checks.
>   - Split initialization in two phases,
>   - Document that ARM cores are controlled by PSCI on R-Car Gen3
>     (although the underlying CPG/APMU hardware is the same as on Gen2),
>   - Minor improvements (double evaluation, unused parameter, debug
>     message consolidation),
>
> v3:
>   - Drop check for CONFIG_PM_GENERIC_DOMAINS, which is now always
>     enabled on R-Car SoCs,
>   - Create PM Domains from hierarchy in C data instead of DT,
>   - Initialize SYSCIER early, as SYSC needs the interrupt sources to be
>     enabled to control power,
>   - Mask all SYSC interrupt sources for the CPU,
>   - Add support for an "always-on" domain,
>   - Use early_initcall() instead of core_initcall(),
>   - Do not power up CPU power areas during initialization, as this is
>     handled later (directly or indirectly) by the SMP code,
>
> v2:
>   - Add missing definitions for SYSC_PWR_CA15_CPU and SYSC_PWR_CA7_CPU,
>   - Add R-Car H3 (r8a7795) support,
>   - Drop tests for CONFIG_ARCH_SHMOBILE_LEGACY,
>   - Add missing break statements in rcar_sysc_pwr_on_off(),
>   - Add missing calls to of_node_put() in error paths,
>   - Fix build if CONFIG_PM=n,
>   - Update compatible values,
>   - Update copyright.
> ---
>  drivers/soc/renesas/rcar-sysc.c | 202 +++++++++++++++++++++++++++++++++++++++-
>  drivers/soc/renesas/rcar-sysc.h |  53 +++++++++++
>  2 files changed, 254 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/soc/renesas/rcar-sysc.h
>
> diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c
> index 9ba5fd15c53bf9b9..95f2b59cbd76f777 100644
> --- a/drivers/soc/renesas/rcar-sysc.c
> +++ b/drivers/soc/renesas/rcar-sysc.c
> @@ -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);
> diff --git a/drivers/soc/renesas/rcar-sysc.h b/drivers/soc/renesas/rcar-sysc.h
> new file mode 100644
> index 0000000000000000..7bb48b4f7334f960
> --- /dev/null
> +++ b/drivers/soc/renesas/rcar-sysc.h
> @@ -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__ */
> --
> 1.9.1
>



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