Re: [PATCH v5] pmdomain: renesas: Add R-Car X5H MDLC driver

On Tue, Aug 11, 2026 at 9:04 PM Geert Uytterhoeven
<[email protected]> wrote:
>
> Add a minimal Module Controller driver for the R-Car X5H (R8A78000) SoC.
> For now this just supports the always-on power domains, and dummy module
> clocks and resets for the serial console (which is enabled by the boot
> loader).
>
> Signed-off-by: Geert Uytterhoeven <[email protected]>

Applied for next, thanks!

Kind regards
Uffe


> ---
> v5:
>   - Drop redundant pd_spec.args_count check in
>     r8a78000_mdlc_attach_dev(),
>
> v4:
>   - Extract from series "[PATCH v3 0/6] R-Car X5H CPG/MDLC support"[1],
>   - Rebase on top of pmdomain/next,
>
> v3:
>   - Replace <linux/mod_devicetable.h> by more specific
>     <linux/device-id/of.h> in v7.2-rc2,
>   - Add a comment to document only always-on domains are supported,
>   - Consistently use /* sentinel */ for zero sentinels,
>   - Drop trailing commas from sentinels,
>
> v2:
>   - Spin off from "pmdomain: renesas: Add R-Car X5H MDLC SCMI remapping
>     driver",
>   - Add default support not using SCMI,
>   - Drop all SCMI remapping support,
>   - Document use of -1 as a sentinel,
>   - Rename struct r8a78000_mdlc_info to mdlc_info,
>   - Print HW IDs in hexadecimal,
>   - Reduce log level for unsupported MDLC instances from warn to dbg,
>
> [1] https://lore.kernel.org/all/[email protected]
> ---
>  drivers/pmdomain/renesas/Kconfig         |   4 +
>  drivers/pmdomain/renesas/Makefile        |   1 +
>  drivers/pmdomain/renesas/r8a78000-mdlc.c | 325 +++++++++++++++++++++++
>  drivers/soc/renesas/Kconfig              |   1 +
>  4 files changed, 331 insertions(+)
>  create mode 100644 drivers/pmdomain/renesas/r8a78000-mdlc.c
>
> diff --git a/drivers/pmdomain/renesas/Kconfig b/drivers/pmdomain/renesas/Kconfig
> index b507c3e0d723efc6..f2f52d3c29a083f1 100644
> --- a/drivers/pmdomain/renesas/Kconfig
> +++ b/drivers/pmdomain/renesas/Kconfig
> @@ -13,6 +13,10 @@ config SYSC_RMOBILE
>         bool "System Controller support for R-Mobile" if COMPILE_TEST
>
>  # SoC
> +config MDLC_R8A78000
> +       bool "Module Controller support for R8A78000 (R-Car X5H)" if COMPILE_TEST
> +       select RESET_CONTROLLER
> +
>  config SYSC_R8A7742
>         bool "System Controller support for R8A7742 (RZ/G1H)" if COMPILE_TEST
>         select SYSC_RCAR
> diff --git a/drivers/pmdomain/renesas/Makefile b/drivers/pmdomain/renesas/Makefile
> index 0391e6e67440a786..17849aad37a5ac4f 100644
> --- a/drivers/pmdomain/renesas/Makefile
> +++ b/drivers/pmdomain/renesas/Makefile
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  # SoC
> +obj-$(CONFIG_MDLC_R8A78000)    += r8a78000-mdlc.o
>  obj-$(CONFIG_SYSC_R8A7742)     += r8a7742-sysc.o
>  obj-$(CONFIG_SYSC_R8A7743)     += r8a7743-sysc.o
>  obj-$(CONFIG_SYSC_R8A7745)     += r8a7745-sysc.o
> diff --git a/drivers/pmdomain/renesas/r8a78000-mdlc.c b/drivers/pmdomain/renesas/r8a78000-mdlc.c
> new file mode 100644
> index 0000000000000000..2668fc2ac9cbd388
> --- /dev/null
> +++ b/drivers/pmdomain/renesas/r8a78000-mdlc.c
> @@ -0,0 +1,325 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * R-Car X5H Module Controller
> + *
> + * Copyright (C) 2026 Glider bv
> + */
> +
> +#include <linux/dev_printk.h>
> +#include <linux/device-id/of.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
> +#include <linux/reset-controller.h>
> +#include <linux/slab.h>
> +
> +#include <dt-bindings/power/renesas,r8a78000-mdlc.h>
> +
> +struct mod_map {
> +       int hw_id;              /* Hardware module ID or -1 sentinel */
> +};
> +
> +struct mdlc_info {
> +       u32 base;
> +       const struct mod_map *mod_map;
> +};
> +
> +/**
> + * struct r8a78000_mdlc_priv - Module Controller Private Data
> + *
> + * @link: Link into list of MDLC instances
> + * @genpd_data: PM domain provider data
> + * @rcdev: Reset controller entity
> + * @dev: MDLC device
> + * @np: Device node in DT representing the MDLC
> + * @mod_map: Mapping from hardware module IDs
> + */
> +struct r8a78000_mdlc_priv {
> +       struct hlist_node link;
> +       struct genpd_onecell_data genpd_data;
> +       struct reset_controller_dev rcdev;
> +       struct device *dev;
> +       struct device_node *np;
> +       const struct mod_map *mod_map;
> +};
> +
> +static struct generic_pm_domain *r8a78000_genpd_always_on;
> +static HLIST_HEAD(r8a78000_mdlc_list);
> +static DEFINE_MUTEX(r8a78000_mdlc_lock);       /* protects the two above */
> +
> +static struct generic_pm_domain *r8a78000_genpd_xlate(
> +                       const struct of_phandle_args *spec, void *data)
> +{
> +       struct r8a78000_mdlc_priv *priv = container_of(data,
> +                                       struct r8a78000_mdlc_priv, genpd_data);
> +       struct device *dev = priv->dev;
> +       u32 id;
> +
> +       if (spec->args_count != 2)
> +               return ERR_PTR(-EINVAL);
> +
> +       id = spec->args[0];
> +
> +       if (id >= R8A78000_MDLC_PD_AON) {
> +               dev_dbg(dev,
> +                       "Mapping HW power domain 0x%x to always-on domain\n",
> +                       id);
> +               return r8a78000_genpd_always_on;
> +       }
> +
> +       /* For now only always-on domains are supported */
> +       dev_err(dev, "Unknown power domain 0x%x\n", id);
> +       return ERR_PTR(-ENOENT);
> +}
> +
> +#define rcdev_to_priv(_rcdev)  \
> +       container_of(_rcdev, struct r8a78000_mdlc_priv, rcdev)
> +
> +static const struct mod_map *mod_map_find(const struct mod_map *map, u32 id)
> +{
> +       if (!map)
> +               return NULL;
> +
> +       for (; map->hw_id >= 0; map++) {
> +               if (map->hw_id == id)
> +                       return map;
> +       }
> +
> +       return NULL;
> +}
> +
> +static int r8a78000_mdlc_reset_xlate(struct reset_controller_dev *rcdev,
> +                                    const struct of_phandle_args *spec)
> +{
> +       struct r8a78000_mdlc_priv *priv = rcdev_to_priv(rcdev);
> +       struct device *dev = priv->dev;
> +       const struct mod_map *map;
> +       u32 id;
> +
> +       if (spec->args_count != 1)
> +               return -EINVAL;
> +
> +       id = spec->args[0];
> +
> +       map = mod_map_find(priv->mod_map, id);
> +       if (!map) {
> +               dev_err(dev, "Unknown reset 0x%x\n", id);
> +               return -ENOENT;
> +       }
> +
> +       dev_dbg(dev, "Ignoring HW reset 0x%x\n", id);
> +       return id;
> +}
> +
> +#define DEFINE_MDLC_RESET_WRAPPER(op)                                      \
> +       static int r8a78000_mdlc_ ## op(struct reset_controller_dev *rcdev, \
> +                                       unsigned long id)                   \
> +       {                                                                   \
> +               struct r8a78000_mdlc_priv *priv = rcdev_to_priv(rcdev);     \
> +                                                                           \
> +               dev_dbg(priv->dev, "%s: Ignoring\n", __func__);             \
> +               return 0;                                                   \
> +       }
> +
> +DEFINE_MDLC_RESET_WRAPPER(reset)
> +DEFINE_MDLC_RESET_WRAPPER(assert)
> +DEFINE_MDLC_RESET_WRAPPER(deassert)
> +DEFINE_MDLC_RESET_WRAPPER(status)
> +
> +static const struct reset_control_ops r8a78000_mdlc_reset_ops = {
> +       .reset = r8a78000_mdlc_reset,
> +       .assert = r8a78000_mdlc_assert,
> +       .deassert = r8a78000_mdlc_deassert,
> +       .status = r8a78000_mdlc_status,
> +};
> +
> +static int r8a78000_mdlc_attach_dev(struct generic_pm_domain *domain,
> +                                   struct device *dev)
> +{
> +       struct device_node *np = dev->of_node;
> +       struct r8a78000_mdlc_priv *priv;
> +       struct of_phandle_args pd_spec;
> +       const struct mod_map *map;
> +       unsigned int id;
> +       int ret;
> +
> +       ret = of_parse_phandle_with_args(np, "power-domains",
> +                                        "#power-domain-cells", 0, &pd_spec);
> +       if (ret < 0)
> +               return ret;
> +
> +       scoped_guard(mutex, &r8a78000_mdlc_lock) {
> +               hlist_for_each_entry(priv, &r8a78000_mdlc_list, link) {
> +                       if (priv->np == pd_spec.np)
> +                               break;
> +               }
> +       }
> +
> +       if (!priv) {
> +               dev_err(dev, "%s: MDLC %pOF not found\n", __func__, pd_spec.np);
> +               of_node_put(pd_spec.np);
> +               return -ENODEV;
> +       }
> +
> +       id = pd_spec.args[1];
> +       of_node_put(pd_spec.np);
> +
> +       map = mod_map_find(priv->mod_map, id);
> +       if (!map) {
> +               dev_err(dev, "Unknown module 0x%x\n", id);
> +               return -ENOENT;
> +       }
> +
> +       dev_dbg(dev, "Ignoring HW module 0x%x\n", id);
> +       return 0;
> +}
> +
> +static void r8a78000_mdlc_unlink(void *data)
> +{
> +       struct r8a78000_mdlc_priv *priv = data;
> +
> +       scoped_guard(mutex, &r8a78000_mdlc_lock) {
> +               hlist_del(&priv->link);
> +       }
> +}
> +
> +static void r8a78000_genpd_del_provider(void *data)
> +{
> +       of_genpd_del_provider(data);
> +}
> +
> +static int r8a78000_genpd_always_on_singleton(struct device *dev)
> +{
> +       struct generic_pm_domain *genpd;
> +       int ret;
> +
> +       guard(mutex)(&r8a78000_mdlc_lock);
> +
> +       if (r8a78000_genpd_always_on)
> +               return 0;
> +
> +       genpd = kzalloc_obj(*genpd);
> +       if (!genpd)
> +               return -ENOMEM;
> +
> +       genpd->name = "always-on";
> +       genpd->attach_dev = r8a78000_mdlc_attach_dev;
> +
> +       ret = pm_genpd_init(genpd, &pm_domain_always_on_gov, false);
> +       if (ret) {
> +               kfree(genpd);
> +               return dev_err_probe(dev, ret,
> +                                    "Failed to create always-on domain\n");
> +       }
> +
> +       r8a78000_genpd_always_on = genpd;
> +       return 0;
> +}
> +
> +static int r8a78000_mdlc_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct device_node *np = dev->of_node;
> +       struct r8a78000_mdlc_priv *priv;
> +       const struct mdlc_info *info;
> +       struct resource *res;
> +       int ret;
> +
> +       ret = r8a78000_genpd_always_on_singleton(dev);
> +       if (ret)
> +               return ret;
> +
> +       info = of_device_get_match_data(dev);
> +       if (!info)
> +               return -ENODEV;
> +
> +       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +       if (!priv)
> +               return -ENOMEM;
> +
> +       priv->dev = dev;
> +       priv->np = np;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       if (!res)
> +               return -ENODEV;
> +
> +       for (; info->base; info++) {
> +               if (info->base == res->start)
> +                       break;
> +       }
> +
> +       if (!info->base) {
> +               dev_dbg(dev, "Unsupported MDLC instance 0x%pa\n", &res->start);
> +               return -ENODEV;
> +       }
> +
> +       priv->mod_map = info->mod_map;
> +
> +       scoped_guard(mutex, &r8a78000_mdlc_lock) {
> +               hlist_add_head(&priv->link, &r8a78000_mdlc_list);
> +       }
> +
> +       ret = devm_add_action_or_reset(dev, r8a78000_mdlc_unlink, priv);
> +       if (ret)
> +               return dev_err_probe(dev, ret, "failed to add action\n");
> +
> +       /* Note that no actual domains are registered, just need translation */
> +       priv->genpd_data.xlate = r8a78000_genpd_xlate;
> +       ret = of_genpd_add_provider_onecell(np, &priv->genpd_data);
> +       if (ret)
> +               return dev_err_probe(dev, ret,
> +                                    "Failed to register genpd provider\n");
> +
> +       ret = devm_add_action_or_reset(dev, r8a78000_genpd_del_provider, np);
> +       if (ret)
> +               return dev_err_probe(dev, ret,
> +                                    "failed to add unregister action\n");
> +
> +       priv->rcdev.ops = &r8a78000_mdlc_reset_ops;
> +       priv->rcdev.of_node = np;
> +       priv->rcdev.of_reset_n_cells = 1;
> +       priv->rcdev.of_xlate = r8a78000_mdlc_reset_xlate;
> +
> +       ret = devm_reset_controller_register(dev, &priv->rcdev);
> +       if (ret)
> +               return dev_err_probe(dev, ret,
> +                                    "Failed to register reset controller\n");
> +
> +       return 0;
> +}
> +
> +static const struct mod_map r8a78000_mdlc_perw_mod_default[] = {
> +       { 0x54 },       /* HSCIF0 */
> +       { -1 }
> +};
> +
> +static const struct mdlc_info r8a78000_mdlc_default[] = {
> +       {
> +               .base = 0xc05d0000 /* mdlc_perw */,
> +               .mod_map = r8a78000_mdlc_perw_mod_default,
> +       },
> +       { /* sentinel */ }
> +};
> +
> +static const struct of_device_id r8a78000_mdlc_match[] = {
> +       {
> +               .compatible = "renesas,r8a78000-mdlc",
> +               .data = &r8a78000_mdlc_default,
> +       },
> +       { /* sentinel */ }
> +};
> +
> +static struct platform_driver r8a78000_mdlc_driver = {
> +       .probe = r8a78000_mdlc_probe,
> +       .driver = {
> +               .name = "r8a78000-mdlc",
> +               .of_match_table = r8a78000_mdlc_match,
> +               .suppress_bind_attrs = true,
> +       },
> +};
> +
> +builtin_platform_driver(r8a78000_mdlc_driver)
> +
> +MODULE_DESCRIPTION("R-Car X5H MDLC Driver");
> diff --git a/drivers/soc/renesas/Kconfig b/drivers/soc/renesas/Kconfig
> index 2ab150d04bb1f1ef..d4055250de72f1fe 100644
> --- a/drivers/soc/renesas/Kconfig
> +++ b/drivers/soc/renesas/Kconfig
> @@ -358,6 +358,7 @@ config ARCH_R8A78000
>         default y if ARCH_RENESAS
>         default ARCH_RENESAS
>         select ARCH_RCAR_GEN5
> +       select MDLC_R8A78000
>         help
>           This enables support for the Renesas R-Car X5H SoC.
>
> --
> 2.43.0
>