Re: [PATCH v2 04/14] reset: starfive: Factor out common JH71X0 reset code
From: Emil Renner Berthing
Date: Fri Nov 18 2022 - 11:40:00 EST
On Fri, 18 Nov 2022 at 02:06, Hal Feng <hal.feng@xxxxxxxxxxxxxxxx> wrote:
>
> From: Emil Renner Berthing <kernel@xxxxxxxx>
>
> The StarFive JH7100 SoC has additional reset controllers for audio and
> video, but the registers follow the same structure. On the JH7110 the
> reset registers don't get their own memory range, but instead follow the
> clock control registers. The registers still follow the same structure
> though, so let's factor out the common code to handle all these cases.
>
> Signed-off-by: Emil Renner Berthing <kernel@xxxxxxxx>
> Co-developed-by: Hal Feng <hal.feng@xxxxxxxxxxxxxxxx>
> Signed-off-by: Hal Feng <hal.feng@xxxxxxxxxxxxxxxx>
> ---
> drivers/reset/starfive/Kconfig | 4 +
> drivers/reset/starfive/Makefile | 2 +
> .../reset/starfive/reset-starfive-jh7100.c | 121 ++----------------
> ...rfive-jh7100.c => reset-starfive-jh71x0.c} | 92 ++++---------
> .../reset/starfive/reset-starfive-jh71x0.h | 14 ++
> 5 files changed, 56 insertions(+), 177 deletions(-)
> copy drivers/reset/starfive/{reset-starfive-jh7100.c => reset-starfive-jh71x0.c} (50%)
> create mode 100644 drivers/reset/starfive/reset-starfive-jh71x0.h
>
> diff --git a/drivers/reset/starfive/Kconfig b/drivers/reset/starfive/Kconfig
> index cddebdba7177..9d15c4110e40 100644
> --- a/drivers/reset/starfive/Kconfig
> +++ b/drivers/reset/starfive/Kconfig
> @@ -1,8 +1,12 @@
> # SPDX-License-Identifier: GPL-2.0-only
>
> +config RESET_STARFIVE_JH71X0
> + bool
> +
> config RESET_STARFIVE_JH7100
> bool "StarFive JH7100 Reset Driver"
> depends on SOC_STARFIVE || COMPILE_TEST
> + select RESET_STARFIVE_JH71X0
> default SOC_STARFIVE
> help
> This enables the reset controller driver for the StarFive JH7100 SoC.
> diff --git a/drivers/reset/starfive/Makefile b/drivers/reset/starfive/Makefile
> index 670d049423f5..f6aa12466fad 100644
> --- a/drivers/reset/starfive/Makefile
> +++ b/drivers/reset/starfive/Makefile
> @@ -1,2 +1,4 @@
> # SPDX-License-Identifier: GPL-2.0
> +obj-$(CONFIG_RESET_STARFIVE_JH71X0) += reset-starfive-jh71x0.o
> +
> obj-$(CONFIG_RESET_STARFIVE_JH7100) += reset-starfive-jh7100.o
> diff --git a/drivers/reset/starfive/reset-starfive-jh7100.c b/drivers/reset/starfive/reset-starfive-jh7100.c
> index fc44b2fb3e03..43248e8135fd 100644
> --- a/drivers/reset/starfive/reset-starfive-jh7100.c
> +++ b/drivers/reset/starfive/reset-starfive-jh7100.c
> @@ -5,14 +5,10 @@
> * Copyright (C) 2021 Emil Renner Berthing <kernel@xxxxxxxx>
> */
>
> -#include <linux/bitmap.h>
> -#include <linux/io.h>
> -#include <linux/io-64-nonatomic-lo-hi.h>
> -#include <linux/iopoll.h>
> #include <linux/mod_devicetable.h>
> #include <linux/platform_device.h>
> -#include <linux/reset-controller.h>
> -#include <linux/spinlock.h>
> +
> +#include "reset-starfive-jh71x0.h"
>
> #include <dt-bindings/reset/starfive-jh7100.h>
>
> @@ -48,114 +44,19 @@ static const u64 jh7100_reset_asserted[2] = {
> 0,
> };
>
> -struct jh7100_reset {
> - struct reset_controller_dev rcdev;
> - /* protect registers against concurrent read-modify-write */
> - spinlock_t lock;
> - void __iomem *base;
> -};
> -
> -static inline struct jh7100_reset *
> -jh7100_reset_from(struct reset_controller_dev *rcdev)
> -{
> - return container_of(rcdev, struct jh7100_reset, rcdev);
> -}
> -
> -static int jh7100_reset_update(struct reset_controller_dev *rcdev,
> - unsigned long id, bool assert)
> -{
> - struct jh7100_reset *data = jh7100_reset_from(rcdev);
> - unsigned long offset = BIT_ULL_WORD(id);
> - u64 mask = BIT_ULL_MASK(id);
> - void __iomem *reg_assert = data->base + JH7100_RESET_ASSERT0 + offset * sizeof(u64);
> - void __iomem *reg_status = data->base + JH7100_RESET_STATUS0 + offset * sizeof(u64);
> - u64 done = jh7100_reset_asserted[offset] & mask;
> - u64 value;
> - unsigned long flags;
> - int ret;
> -
> - if (!assert)
> - done ^= mask;
> -
> - spin_lock_irqsave(&data->lock, flags);
> -
> - value = readq(reg_assert);
> - if (assert)
> - value |= mask;
> - else
> - value &= ~mask;
> - writeq(value, reg_assert);
> -
> - /* if the associated clock is gated, deasserting might otherwise hang forever */
> - ret = readq_poll_timeout_atomic(reg_status, value, (value & mask) == done, 0, 1000);
> -
> - spin_unlock_irqrestore(&data->lock, flags);
> - return ret;
> -}
> -
> -static int jh7100_reset_assert(struct reset_controller_dev *rcdev,
> - unsigned long id)
> -{
> - return jh7100_reset_update(rcdev, id, true);
> -}
> -
> -static int jh7100_reset_deassert(struct reset_controller_dev *rcdev,
> - unsigned long id)
> -{
> - return jh7100_reset_update(rcdev, id, false);
> -}
> -
> -static int jh7100_reset_reset(struct reset_controller_dev *rcdev,
> - unsigned long id)
> -{
> - int ret;
> -
> - ret = jh7100_reset_assert(rcdev, id);
> - if (ret)
> - return ret;
> -
> - return jh7100_reset_deassert(rcdev, id);
> -}
> -
> -static int jh7100_reset_status(struct reset_controller_dev *rcdev,
> - unsigned long id)
> -{
> - struct jh7100_reset *data = jh7100_reset_from(rcdev);
> - unsigned long offset = BIT_ULL_WORD(id);
> - u64 mask = BIT_ULL_MASK(id);
> - void __iomem *reg_status = data->base + JH7100_RESET_STATUS0 + offset * sizeof(u64);
> - u64 value = readq(reg_status);
> -
> - return !((value ^ jh7100_reset_asserted[offset]) & mask);
> -}
> -
> -static const struct reset_control_ops jh7100_reset_ops = {
> - .assert = jh7100_reset_assert,
> - .deassert = jh7100_reset_deassert,
> - .reset = jh7100_reset_reset,
> - .status = jh7100_reset_status,
> -};
> -
> static int __init jh7100_reset_probe(struct platform_device *pdev)
> {
> - struct jh7100_reset *data;
> -
> - data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> - if (!data)
> - return -ENOMEM;
> -
> - data->base = devm_platform_ioremap_resource(pdev, 0);
> - if (IS_ERR(data->base))
> - return PTR_ERR(data->base);
> + void __iomem *base = devm_platform_ioremap_resource(pdev, 0);
>
> - data->rcdev.ops = &jh7100_reset_ops;
> - data->rcdev.owner = THIS_MODULE;
> - data->rcdev.nr_resets = JH7100_RSTN_END;
> - data->rcdev.dev = &pdev->dev;
> - data->rcdev.of_node = pdev->dev.of_node;
> - spin_lock_init(&data->lock);
> + if (IS_ERR(base))
> + return PTR_ERR(base);
>
> - return devm_reset_controller_register(&pdev->dev, &data->rcdev);
> + return reset_starfive_jh7100_register(&pdev->dev, pdev->dev.of_node,
> + base + JH7100_RESET_ASSERT0,
> + base + JH7100_RESET_STATUS0,
> + jh7100_reset_asserted,
> + JH7100_RSTN_END,
> + true);
> }
>
> static const struct of_device_id jh7100_reset_dt_ids[] = {
> diff --git a/drivers/reset/starfive/reset-starfive-jh7100.c b/drivers/reset/starfive/reset-starfive-jh71x0.c
> similarity index 50%
> copy from drivers/reset/starfive/reset-starfive-jh7100.c
> copy to drivers/reset/starfive/reset-starfive-jh71x0.c
> index fc44b2fb3e03..1e230f3f9841 100644
> --- a/drivers/reset/starfive/reset-starfive-jh7100.c
> +++ b/drivers/reset/starfive/reset-starfive-jh71x0.c
> @@ -6,53 +6,20 @@
> */
>
> #include <linux/bitmap.h>
> +#include <linux/device.h>
> #include <linux/io.h>
> #include <linux/io-64-nonatomic-lo-hi.h>
> #include <linux/iopoll.h>
> -#include <linux/mod_devicetable.h>
> -#include <linux/platform_device.h>
> #include <linux/reset-controller.h>
> #include <linux/spinlock.h>
>
> -#include <dt-bindings/reset/starfive-jh7100.h>
> -
> -/* register offsets */
> -#define JH7100_RESET_ASSERT0 0x00
> -#define JH7100_RESET_ASSERT1 0x04
> -#define JH7100_RESET_ASSERT2 0x08
> -#define JH7100_RESET_ASSERT3 0x0c
> -#define JH7100_RESET_STATUS0 0x10
> -#define JH7100_RESET_STATUS1 0x14
> -#define JH7100_RESET_STATUS2 0x18
> -#define JH7100_RESET_STATUS3 0x1c
> -
> -/*
> - * Writing a 1 to the n'th bit of the m'th ASSERT register asserts
> - * line 32m + n, and writing a 0 deasserts the same line.
> - * Most reset lines have their status inverted so a 0 bit in the STATUS
> - * register means the line is asserted and a 1 means it's deasserted. A few
> - * lines don't though, so store the expected value of the status registers when
> - * all lines are asserted.
> - */
> -static const u64 jh7100_reset_asserted[2] = {
> - /* STATUS0 */
> - BIT_ULL_MASK(JH7100_RST_U74) |
> - BIT_ULL_MASK(JH7100_RST_VP6_DRESET) |
> - BIT_ULL_MASK(JH7100_RST_VP6_BRESET) |
> - /* STATUS1 */
> - BIT_ULL_MASK(JH7100_RST_HIFI4_DRESET) |
> - BIT_ULL_MASK(JH7100_RST_HIFI4_BRESET),
> - /* STATUS2 */
> - BIT_ULL_MASK(JH7100_RST_E24) |
> - /* STATUS3 */
> - 0,
> -};
> -
> struct jh7100_reset {
> struct reset_controller_dev rcdev;
> /* protect registers against concurrent read-modify-write */
> spinlock_t lock;
> - void __iomem *base;
> + void __iomem *assert;
> + void __iomem *status;
> + const u64 *asserted;
> };
>
> static inline struct jh7100_reset *
> @@ -67,9 +34,9 @@ static int jh7100_reset_update(struct reset_controller_dev *rcdev,
> struct jh7100_reset *data = jh7100_reset_from(rcdev);
> unsigned long offset = BIT_ULL_WORD(id);
> u64 mask = BIT_ULL_MASK(id);
> - void __iomem *reg_assert = data->base + JH7100_RESET_ASSERT0 + offset * sizeof(u64);
> - void __iomem *reg_status = data->base + JH7100_RESET_STATUS0 + offset * sizeof(u64);
> - u64 done = jh7100_reset_asserted[offset] & mask;
> + void __iomem *reg_assert = data->assert + offset * sizeof(u64);
> + void __iomem *reg_status = data->status + offset * sizeof(u64);
> + u64 done = data->asserted ? data->asserted[offset] & mask : 0;
> u64 value;
> unsigned long flags;
> int ret;
> @@ -123,10 +90,10 @@ static int jh7100_reset_status(struct reset_controller_dev *rcdev,
> struct jh7100_reset *data = jh7100_reset_from(rcdev);
> unsigned long offset = BIT_ULL_WORD(id);
> u64 mask = BIT_ULL_MASK(id);
> - void __iomem *reg_status = data->base + JH7100_RESET_STATUS0 + offset * sizeof(u64);
> + void __iomem *reg_status = data->status + offset * sizeof(u64);
> u64 value = readq(reg_status);
>
> - return !((value ^ jh7100_reset_asserted[offset]) & mask);
> + return !((value ^ data->asserted[offset]) & mask);
> }
>
> static const struct reset_control_ops jh7100_reset_ops = {
> @@ -136,38 +103,29 @@ static const struct reset_control_ops jh7100_reset_ops = {
> .status = jh7100_reset_status,
> };
>
> -static int __init jh7100_reset_probe(struct platform_device *pdev)
> +int reset_starfive_jh7100_register(struct device *dev, struct device_node *of_node,
> + void __iomem *assert, void __iomem *status,
> + const u64 *asserted, unsigned int nr_resets,
> + bool is_module)
> {
> struct jh7100_reset *data;
>
> - data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> if (!data)
> return -ENOMEM;
>
> - data->base = devm_platform_ioremap_resource(pdev, 0);
> - if (IS_ERR(data->base))
> - return PTR_ERR(data->base);
> -
> data->rcdev.ops = &jh7100_reset_ops;
> - data->rcdev.owner = THIS_MODULE;
> - data->rcdev.nr_resets = JH7100_RSTN_END;
> - data->rcdev.dev = &pdev->dev;
> - data->rcdev.of_node = pdev->dev.of_node;
> + if (is_module)
> + data->rcdev.owner = THIS_MODULE;
nit: consider just passing the owner directly, so this would just be
data->rcdev.owner = owner;
..and callers that used false can just pass NULL.
> + data->rcdev.nr_resets = nr_resets;
> + data->rcdev.dev = dev;
> + data->rcdev.of_node = of_node;
Is it important to register this with the auxiliary device and not
just use the parent device?
If not you can just always pass the device that has the right of_node
and have this be
data->rcdev.of_node = dev->of_node;
> +
> spin_lock_init(&data->lock);
> + data->assert = assert;
> + data->status = status;
> + data->asserted = asserted;
>
> - return devm_reset_controller_register(&pdev->dev, &data->rcdev);
> + return devm_reset_controller_register(dev, &data->rcdev);
> }
> -
> -static const struct of_device_id jh7100_reset_dt_ids[] = {
> - { .compatible = "starfive,jh7100-reset" },
> - { /* sentinel */ }
> -};
> -
> -static struct platform_driver jh7100_reset_driver = {
> - .driver = {
> - .name = "jh7100-reset",
> - .of_match_table = jh7100_reset_dt_ids,
> - .suppress_bind_attrs = true,
> - },
> -};
> -builtin_platform_driver_probe(jh7100_reset_driver, jh7100_reset_probe);
> +EXPORT_SYMBOL_GPL(reset_starfive_jh7100_register);
> diff --git a/drivers/reset/starfive/reset-starfive-jh71x0.h b/drivers/reset/starfive/reset-starfive-jh71x0.h
> new file mode 100644
> index 000000000000..10770c55ab0e
> --- /dev/null
> +++ b/drivers/reset/starfive/reset-starfive-jh71x0.h
> @@ -0,0 +1,14 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2021 Emil Renner Berthing <kernel@xxxxxxxx>
> + */
> +
> +#ifndef __RESET_STARFIVE_JH71X0_H
> +#define __RESET_STARFIVE_JH71X0_H
> +
> +int reset_starfive_jh7100_register(struct device *dev, struct device_node *of_node,
> + void __iomem *assert, void __iomem *status,
> + const u64 *asserted, unsigned int nr_resets,
> + bool is_module);
> +
> +#endif /* __RESET_STARFIVE_JH71X0_H */
> --
> 2.38.1
>