On Mon, 2021-11-01 at 13:01 +0800, Qin Jian wrote:
> Add reset driver for Sunplus SP7021 SoC.
You don't mention Q645 here, it appears this driver supports both SoCs?
[...]
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index be799a5ab..50695ab47 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -249,6 +249,14 @@ config RESET_TI_SYSCON
> you wish to use the reset framework for such memory-mapped devices,
> say Y here. Otherwise, say N.
>
>
> +config RESET_SUNPLUS
Please add these entries in alphabetical order.
> + bool "Sunplus SoCs Reset Driver"
Can this be made:
depends SOC_SP7021 || SOC_Q645 || COMPILE_TEST
?
> + help
> + This enables the reset driver support for Sunplus SP7021 SoC family.
> + Say Y if you want to control reset signals by the reset controller.
> + Otherwise, say N.
> + This driver is selected automatically by platform config.
Which platform config?
[...]
> diff --git a/drivers/reset/reset-sunplus.c b/drivers/reset/reset-sunplus.c
> new file mode 100644
> index 000000000..696efd75e
> --- /dev/null
> +++ b/drivers/reset/reset-sunplus.c
> @@ -0,0 +1,159 @@
> +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +/*
> + * SP7021 reset driver
> + *
> + * Copyright (C) Sunplus Technology Co., Ltd.
> + * All rights reserved.
> + *
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether express or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
Drop this boilerplate, this is not required with the SPDX identifier
above.
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset-controller.h>
> +#include <linux/reboot.h>
> +
> +#if defined(CONFIG_SOC_SP7021)
> +#include <dt-bindings/reset/sp-sp7021.h>
> +#elif defined(CONFIG_SOC_Q645)
> +#include <dt-bindings/reset/sp-q645.h>
> +#endif
I'd prefer if you added namespace prefixes to the defines and included
both headers unconditionally.
These are just required for RST_MAX, correct?
> +
> +#define BITASSERT(id, val) ((1 << (16 + id)) | (val << id))
> +
> +
> +struct sp_reset_data {
> + struct reset_controller_dev rcdev;
> + void __iomem *membase;
> +} sp_reset;
Please allocate this with devm_kzalloc in the probe function instead.
> +
> +
> +static inline struct sp_reset_data *
> +to_sp_reset_data(struct reset_controller_dev *rcdev)
> +{
> + return container_of(rcdev, struct sp_reset_data, rcdev);
> +}
> +
> +static int sp_reset_update(struct reset_controller_dev *rcdev,
> + unsigned long id, bool assert)
> +{
> + struct sp_reset_data *data = to_sp_reset_data(rcdev);
> + int reg_width = sizeof(u32)/2;
> + int bank = id / (reg_width * BITS_PER_BYTE);
> + int offset = id % (reg_width * BITS_PER_BYTE);
> + void __iomem *addr;
> +
> + addr = data->membase + (bank * 4);
> +
> + if (assert)
> + writel(BITASSERT(offset, 1), addr);
> + else
> + writel(BITASSERT(offset, 0), addr);
Could be
writel(BITASSERT(offset, assert), addr);
> +
> + return 0;
> +}
> +
> +static int sp_reset_assert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + return sp_reset_update(rcdev, id, true);
> +}
> +
> +
> +static int sp_reset_deassert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + return sp_reset_update(rcdev, id, false);
> +}
> +
> +static int sp_reset_status(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + struct sp_reset_data *data = to_sp_reset_data(rcdev);
> + int reg_width = sizeof(u32)/2;
> + int bank = id / (reg_width * BITS_PER_BYTE);
> + int offset = id % (reg_width * BITS_PER_BYTE);
> + u32 reg;
> +
> + reg = readl(data->membase + (bank * 4));
> +
> + return !!(reg & BIT(offset));
> +}
> +
> +static int sp_restart(struct notifier_block *this, unsigned long mode,
> + void *cmd)
> +{
> + sp_reset_assert(&sp_reset.rcdev, RST_SYSTEM);
> + sp_reset_deassert(&sp_reset.rcdev, RST_SYSTEM);
> +
> + return NOTIFY_DONE;
> +}
> +
> +static struct notifier_block sp_restart_nb = {
> + .notifier_call = sp_restart,
> + .priority = 192,
> +};
> +
> +static const struct reset_control_ops sp_reset_ops = {
> + .assert = sp_reset_assert,
> + .deassert = sp_reset_deassert,
> + .status = sp_reset_status,
> +};
> +
> +static const struct of_device_id sp_reset_dt_ids[] = {
> + { .compatible = "sunplus,sp7021-reset", },
> + { .compatible = "sunplus,q645-reset", },
> + { /* sentinel */ },
> +};
> +
> +static int sp_reset_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct sp_reset_data *data = &sp_reset;
> + void __iomem *membase;
> + struct resource *res;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + membase = devm_ioremap(dev, res->start, resource_size(res));
> + if (IS_ERR(membase))
> + return PTR_ERR(membase);
> +
> + data->membase = membase;
> + data->rcdev.owner = THIS_MODULE;
> + data->rcdev.nr_resets = RST_MAX;
Use of_device_get_match_data() to determine the correct number of
resets.
regards
Philipp
