[v1] Add driver support for ESWIN eic7700 SoC reset controller

[PATCH 2/2] reset: eswin: Add eic7700 reset driver

Posted by dongxuyang@eswincomputing.com 9 months ago

From: Xuyang Dong <dongxuyang@eswincomputing.com>

Add support for reset controller in eic7700 series chips.
Provide functionality for asserting and deasserting resets
on the chip.

Signed-off-by: Yifeng Huang <huangyifeng@eswincomputing.com>
Signed-off-by: Xuyang Dong <dongxuyang@eswincomputing.com>
---
 drivers/reset/Kconfig         |   9 ++
 drivers/reset/Makefile        |   1 +
 drivers/reset/reset-eic7700.c | 249 ++++++++++++++++++++++++++++++++++
 3 files changed, 259 insertions(+)
 create mode 100644 drivers/reset/reset-eic7700.c

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 99f6f9784e68..d6eef5358e13 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -350,6 +350,15 @@ config RESET_ZYNQMP
 	help
 	  This enables the reset controller driver for Xilinx ZynqMP SoCs.
 
+config RESET_EIC7700
+	bool "Reset controller driver for Eswin SoCs"
+	default ARCH_ESWIN
+	help
+	  This enables the reset controller driver for Eswin SoCs. This driver is
+	  specific to Eswin SoCs and should only be enabled if using such hardware.
+	  The driver supports eic7700 series chips and provides functionality for
+	  asserting and deasserting resets on the chip.
+
 source "drivers/reset/amlogic/Kconfig"
 source "drivers/reset/starfive/Kconfig"
 source "drivers/reset/sti/Kconfig"
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 31f9904d13f9..2210c4e55834 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -44,3 +44,4 @@ obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
 obj-$(CONFIG_RESET_UNIPHIER_GLUE) += reset-uniphier-glue.o
 obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o
 obj-$(CONFIG_RESET_ZYNQMP) += reset-zynqmp.o
+obj-$(CONFIG_RESET_EIC7700) += reset-eic7700.o
diff --git a/drivers/reset/reset-eic7700.c b/drivers/reset/reset-eic7700.c
new file mode 100644
index 000000000000..079647280cbc
--- /dev/null
+++ b/drivers/reset/reset-eic7700.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2024, Beijing ESWIN Computing Technology Co., Ltd.. All rights reserved.
+ *
+ * ESWIN Reset Driver
+ *
+ * Authors:
+ *	Yifeng Huang <huangyifeng@eswincomputing.com>
+ *	Xuyang Dong <dongxuyang@eswincomputing.com>
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#define SYSCRG_CLEAR_BOOT_INFO_OFFSET (0x30C)
+#define CLEAR_BOOT_FLAG_BIT BIT_ULL(0)
+
+#define SYSCRG_RESET_OFFSET (0x400)
+
+/**
+ * struct eswin_reset_data - reset controller information structure
+ * @rcdev: reset controller entity
+ * @dev: reset controller device pointer
+ * @idr: idr structure for mapping ids to reset control structures
+ */
+struct eswin_reset_data {
+	struct reset_controller_dev rcdev;
+	struct device *dev;
+	struct idr idr;
+	struct regmap *regmap;
+};
+
+/**
+ * struct eswin_reset_control - reset control structure
+ * @dev_id: SoC-specific device identifier
+ * @reset_bit: reset mask to use for toggling reset
+ */
+struct eswin_reset_control {
+	u32 dev_id;
+	u32 reset_bit;
+};
+
+#define to_eswin_reset_data(p) container_of((p), struct eswin_reset_data, rcdev)
+
+/**
+ * eswin_reset_set() - program a device's reset
+ * @rcdev: reset controller entity
+ * @id: ID of the reset to toggle
+ * @assert: boolean flag to indicate assert or deassert
+ *
+ * This is a common internal function used to assert or deassert a device's
+ * reset by clear and set the reset bit. The device's reset is asserted if the
+ * @assert argument is true, or deasserted if @assert argument is false.
+ *
+ * Return: 0 for successful request, else a corresponding error value
+ */
+static int eswin_reset_set(struct reset_controller_dev *rcdev, unsigned long id,
+			   bool assert)
+{
+	struct eswin_reset_data *data = to_eswin_reset_data(rcdev);
+	struct eswin_reset_control *control;
+	int ret;
+
+	control = idr_find(&data->idr, id);
+
+	dev_dbg(rcdev->dev, "dev_id 0x%x reset_bit 0x%x assert 0x%x\r\n",
+		control->dev_id, control->reset_bit, assert);
+
+	if (!control)
+		return -EINVAL;
+
+	if (assert) {
+		ret = regmap_clear_bits(data->regmap,
+					SYSCRG_RESET_OFFSET +
+						control->dev_id * sizeof(u32),
+					control->reset_bit);
+	} else {
+		ret = regmap_set_bits(data->regmap,
+				      SYSCRG_RESET_OFFSET +
+					      control->dev_id * sizeof(u32),
+				      control->reset_bit);
+	}
+
+	return ret;
+}
+
+static int eswin_reset_reset(struct reset_controller_dev *rcdev,
+			     unsigned long id)
+{
+	int ret;
+
+	ret = eswin_reset_set(rcdev, id, true);
+	if (ret != 0)
+		return ret;
+
+	usleep_range(10, 15);
+	ret = eswin_reset_set(rcdev, id, false);
+	if (ret != 0)
+		return ret;
+
+	return 0;
+}
+
+static int eswin_reset_assert(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	return eswin_reset_set(rcdev, id, true);
+}
+
+static int eswin_reset_deassert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	return eswin_reset_set(rcdev, id, false);
+}
+
+static const struct reset_control_ops eswin_reset_ops = {
+	.reset = eswin_reset_reset,
+	.assert = eswin_reset_assert,
+	.deassert = eswin_reset_deassert,
+};
+
+static int eswin_reset_of_xlate_lookup_id(int id, void *p, void *data)
+{
+	struct of_phandle_args *reset_spec = (struct of_phandle_args *)data;
+	struct eswin_reset_control *slot_control =
+		(struct eswin_reset_control *)p;
+
+	if (reset_spec->args[0] == slot_control->dev_id &&
+	    reset_spec->args[1] == slot_control->reset_bit)
+		return id;
+	else
+		return 0;
+}
+
+/**
+ * eswin_reset_of_xlate() - translate a set of OF arguments to a reset ID
+ * @rcdev: reset controller entity
+ * @reset_spec: OF reset argument specifier
+ *
+ * This function performs the translation of the reset argument specifier
+ * values defined in a reset consumer device node. The function allocates a
+ * reset control structure for that device reset, and will be used by the
+ * driver for performing any reset functions on that reset. An idr structure
+ * is allocated and used to map to the reset control structure. This idr
+ * is used by the driver to do reset lookups.
+ *
+ * Return: 0 for successful request, else a corresponding error value
+ */
+static int eswin_reset_of_xlate(struct reset_controller_dev *rcdev,
+				const struct of_phandle_args *reset_spec)
+{
+	struct eswin_reset_data *data = to_eswin_reset_data(rcdev);
+	struct eswin_reset_control *control;
+	int ret;
+
+	if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
+		return -EINVAL;
+
+	ret = idr_for_each(&data->idr, eswin_reset_of_xlate_lookup_id,
+			   (void *)reset_spec);
+	if (ret != 0)
+		return ret;
+
+	control = devm_kzalloc(data->dev, sizeof(*control), GFP_KERNEL);
+	if (!control)
+		return -ENOMEM;
+
+	control->dev_id = reset_spec->args[0];
+	control->reset_bit = reset_spec->args[1];
+
+	return idr_alloc(&data->idr, control, 0, 0, GFP_KERNEL);
+}
+
+static const struct of_device_id eswin_reset_dt_ids[] = {
+	{
+		.compatible = "eswin,eic7700-reset",
+	},
+	{ /* sentinel */ },
+};
+
+static int eswin_reset_probe(struct platform_device *pdev)
+{
+	struct eswin_reset_data *data;
+	struct device *parent;
+
+	parent = pdev->dev.parent;
+	if (!parent) {
+		dev_err(&pdev->dev, "no parent\n");
+		return -ENODEV;
+	}
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->regmap = syscon_node_to_regmap(parent->of_node);
+	if (IS_ERR(data->regmap)) {
+		dev_err(&pdev->dev, "failed to get parent regmap\n");
+		return PTR_ERR(data->regmap);
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.ops = &eswin_reset_ops;
+	data->rcdev.of_node = pdev->dev.of_node;
+	data->rcdev.of_reset_n_cells = 2;
+	data->rcdev.of_xlate = eswin_reset_of_xlate;
+	data->rcdev.dev = &pdev->dev;
+	data->dev = &pdev->dev;
+	idr_init(&data->idr);
+
+	/*clear boot flag so u84 and scpu could be reseted by software*/
+	regmap_set_bits(data->regmap, SYSCRG_CLEAR_BOOT_INFO_OFFSET,
+			CLEAR_BOOT_FLAG_BIT);
+	msleep(50);
+	platform_set_drvdata(pdev, data);
+
+	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
+}
+
+static void eswin_reset_remove(struct platform_device *pdev)
+{
+	struct eswin_reset_data *data = platform_get_drvdata(pdev);
+
+	idr_destroy(&data->idr);
+}
+
+static struct platform_driver eswin_reset_driver = {
+	.probe	= eswin_reset_probe,
+	.remove = eswin_reset_remove,
+	.driver = {
+		.name		= "eswin-reset",
+		.of_match_table	= eswin_reset_dt_ids,
+	},
+};
+
+static int __init eswin_reset_init(void)
+{
+	return platform_driver_register(&eswin_reset_driver);
+}
+arch_initcall(eswin_reset_init);
-- 
2.17.1

Re: [PATCH 2/2] reset: eswin: Add eic7700 reset driver

Posted by Christophe JAILLET 8 months, 3 weeks ago

Le 14/05/2025 à 02:32, 
dongxuyang-sYo9T6QOUuK8M3too/+dENBPR1lH4CV8@public.gmane.org a écrit :
> From: Xuyang Dong <dongxuyang-sYo9T6QOUuK8M3too/+dENBPR1lH4CV8@public.gmane.org>
> 
> Add support for reset controller in eic7700 series chips.
> Provide functionality for asserting and deasserting resets
> on the chip.

...

> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset-controller.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>

Would be better if fully alphabetically ordered.

> +
> +#define SYSCRG_CLEAR_BOOT_INFO_OFFSET (0x30C)

Unneeded ()

> +#define CLEAR_BOOT_FLAG_BIT BIT_ULL(0)

It is only used as a unsigned int parameter with regmap_set_bits(), so 
why ULL?

> +
> +#define SYSCRG_RESET_OFFSET (0x400)

Unneeded ()

...

> +/**
> + * eswin_reset_set() - program a device's reset
> + * @rcdev: reset controller entity
> + * @id: ID of the reset to toggle
> + * @assert: boolean flag to indicate assert or deassert
> + *
> + * This is a common internal function used to assert or deassert a device's
> + * reset by clear and set the reset bit. The device's reset is asserted if the
> + * @assert argument is true, or deasserted if @assert argument is false.
> + *
> + * Return: 0 for successful request, else a corresponding error value
> + */
> +static int eswin_reset_set(struct reset_controller_dev *rcdev, unsigned long id,
> +			   bool assert)
> +{
> +	struct eswin_reset_data *data = to_eswin_reset_data(rcdev);
> +	struct eswin_reset_control *control;
> +	int ret;
> +
> +	control = idr_find(&data->idr, id);
> +
> +	dev_dbg(rcdev->dev, "dev_id 0x%x reset_bit 0x%x assert 0x%x\r\n",
> +		control->dev_id, control->reset_bit, assert);

We test of control is NULL the line after. So if it can happen, it would 
crash here.

> +
> +	if (!control)
> +		return -EINVAL;
> +
> +	if (assert) {
> +		ret = regmap_clear_bits(data->regmap,
> +					SYSCRG_RESET_OFFSET +
> +						control->dev_id * sizeof(u32),
> +					control->reset_bit);
> +	} else {
> +		ret = regmap_set_bits(data->regmap,
> +				      SYSCRG_RESET_OFFSET +
> +					      control->dev_id * sizeof(u32),
> +				      control->reset_bit);
> +	}

No need fo { } around each of these branches.

> +
> +	return ret;
> +}
> +
> +static int eswin_reset_reset(struct reset_controller_dev *rcdev,
> +			     unsigned long id)
> +{
> +	int ret;
> +
> +	ret = eswin_reset_set(rcdev, id, true);

Would it make sense to use eswin_reset_assert()?

> +	if (ret != 0)
> +		return ret;
> +
> +	usleep_range(10, 15);
> +	ret = eswin_reset_set(rcdev, id, false);

Would it make sense to use eswin_reset_deassert()?

> +	if (ret != 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int eswin_reset_assert(struct reset_controller_dev *rcdev,
> +			      unsigned long id)
> +{
> +	return eswin_reset_set(rcdev, id, true);
> +}
> +
> +static int eswin_reset_deassert(struct reset_controller_dev *rcdev,
> +				unsigned long id)
> +{
> +	return eswin_reset_set(rcdev, id, false);
> +}

...

> +static int eswin_reset_of_xlate_lookup_id(int id, void *p, void *data)
> +{
> +	struct of_phandle_args *reset_spec = (struct of_phandle_args *)data;
> +	struct eswin_reset_control *slot_control =
> +		(struct eswin_reset_control *)p;
> +
> +	if (reset_spec->args[0] == slot_control->dev_id &&
> +	    reset_spec->args[1] == slot_control->reset_bit)
> +		return id;
> +	else

Unneeded else.

> +		return 0;
> +}
> +
> +/**
> + * eswin_reset_of_xlate() - translate a set of OF arguments to a reset ID
> + * @rcdev: reset controller entity
> + * @reset_spec: OF reset argument specifier
> + *
> + * This function performs the translation of the reset argument specifier
> + * values defined in a reset consumer device node. The function allocates a
> + * reset control structure for that device reset, and will be used by the
> + * driver for performing any reset functions on that reset. An idr structure
> + * is allocated and used to map to the reset control structure. This idr
> + * is used by the driver to do reset lookups.
> + *
> + * Return: 0 for successful request, else a corresponding error value
> + */
> +static int eswin_reset_of_xlate(struct reset_controller_dev *rcdev,
> +				const struct of_phandle_args *reset_spec)
> +{
> +	struct eswin_reset_data *data = to_eswin_reset_data(rcdev);
> +	struct eswin_reset_control *control;
> +	int ret;
> +
> +	if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
> +		return -EINVAL;
> +
> +	ret = idr_for_each(&data->idr, eswin_reset_of_xlate_lookup_id,
> +			   (void *)reset_spec);
> +	if (ret != 0)

if (ret)

> +		return ret;
> +
> +	control = devm_kzalloc(data->dev, sizeof(*control), GFP_KERNEL);
> +	if (!control)
> +		return -ENOMEM;
> +
> +	control->dev_id = reset_spec->args[0];
> +	control->reset_bit = reset_spec->args[1];
> +
> +	return idr_alloc(&data->idr, control, 0, 0, GFP_KERNEL);
> +}
> +
> +static const struct of_device_id eswin_reset_dt_ids[] = {
> +	{
> +		.compatible = "eswin,eic7700-reset",
> +	},
> +	{ /* sentinel */ },

No need for a trailing , after a terminator.

> +};
> +
> +static int eswin_reset_probe(struct platform_device *pdev)
> +{
> +	struct eswin_reset_data *data;
> +	struct device *parent;
> +
> +	parent = pdev->dev.parent;
> +	if (!parent) {
> +		dev_err(&pdev->dev, "no parent\n");
> +		return -ENODEV;
> +	}
> +
> +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->regmap = syscon_node_to_regmap(parent->of_node);
> +	if (IS_ERR(data->regmap)) {
> +		dev_err(&pdev->dev, "failed to get parent regmap\n");
> +		return PTR_ERR(data->regmap);
> +	}
> +
> +	platform_set_drvdata(pdev, data);
> +
> +	data->rcdev.owner = THIS_MODULE;
> +	data->rcdev.ops = &eswin_reset_ops;
> +	data->rcdev.of_node = pdev->dev.of_node;
> +	data->rcdev.of_reset_n_cells = 2;
> +	data->rcdev.of_xlate = eswin_reset_of_xlate;
> +	data->rcdev.dev = &pdev->dev;
> +	data->dev = &pdev->dev;
> +	idr_init(&data->idr);
> +
> +	/*clear boot flag so u84 and scpu could be reseted by software*/

Missing spaces at the start and the end of the comment.

> +	regmap_set_bits(data->regmap, SYSCRG_CLEAR_BOOT_INFO_OFFSET,
> +			CLEAR_BOOT_FLAG_BIT);
> +	msleep(50);
> +	platform_set_drvdata(pdev, data);
> +
> +	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
> +}

...

CJ

Re: [PATCH 2/2] reset: eswin: Add eic7700 reset driver

Posted by Krzysztof Kozlowski 8 months, 3 weeks ago

On 14/05/2025 02:32, dongxuyang@eswincomputing.com wrote:
> From: Xuyang Dong <dongxuyang@eswincomputing.com>
> 
> Add support for reset controller in eic7700 series chips.
> Provide functionality for asserting and deasserting resets
> on the chip.
> 
> Signed-off-by: Yifeng Huang <huangyifeng@eswincomputing.com>
> Signed-off-by: Xuyang Dong <dongxuyang@eswincomputing.com>
> ---
>  drivers/reset/Kconfig         |   9 ++
>  drivers/reset/Makefile        |   1 +
>  drivers/reset/reset-eic7700.c | 249 ++++++++++++++++++++++++++++++++++
>  3 files changed, 259 insertions(+)
>  create mode 100644 drivers/reset/reset-eic7700.c
> 
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index 99f6f9784e68..d6eef5358e13 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -350,6 +350,15 @@ config RESET_ZYNQMP
>  	help
>  	  This enables the reset controller driver for Xilinx ZynqMP SoCs.
>  
> +config RESET_EIC7700

E is not after Z. Don't add your entries to the end. This applies to all
your patches.

> +	bool "Reset controller driver for Eswin SoCs"
> +	default ARCH_ESWIN
> +	help
> +	  This enables the reset controller driver for Eswin SoCs. This driver is
> +	  specific to Eswin SoCs and should only be enabled if using such hardware.
> +	  The driver supports eic7700 series chips and provides functionality for
> +	  asserting and deasserting resets on the chip.
> +
>  source "drivers/reset/amlogic/Kconfig"
>  source "drivers/reset/starfive/Kconfig"
>  source "drivers/reset/sti/Kconfig"
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index 31f9904d13f9..2210c4e55834 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -44,3 +44,4 @@ obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
>  obj-$(CONFIG_RESET_UNIPHIER_GLUE) += reset-uniphier-glue.o
>  obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o
>  obj-$(CONFIG_RESET_ZYNQMP) += reset-zynqmp.o
> +obj-$(CONFIG_RESET_EIC7700) += reset-eic7700.o

E is not after Z.


> +static int eswin_reset_probe(struct platform_device *pdev)
> +{
> +	struct eswin_reset_data *data;
> +	struct device *parent;
> +
> +	parent = pdev->dev.parent;
> +	if (!parent) {
> +		dev_err(&pdev->dev, "no parent\n");

Not possible. Fix your DTS otherwise.

> +		return -ENODEV;
> +	}
> +
> +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->regmap = syscon_node_to_regmap(parent->of_node);
> +	if (IS_ERR(data->regmap)) {
> +		dev_err(&pdev->dev, "failed to get parent regmap\n");
> +		return PTR_ERR(data->regmap);

Syntax is always: return dev_err_probe. You already got such comment.
All your patches repeat the same issues.

> +	}
> +
> +	platform_set_drvdata(pdev, data);
> +
> +	data->rcdev.owner = THIS_MODULE;
> +	data->rcdev.ops = &eswin_reset_ops;
> +	data->rcdev.of_node = pdev->dev.of_node;
> +	data->rcdev.of_reset_n_cells = 2;
> +	data->rcdev.of_xlate = eswin_reset_of_xlate;
> +	data->rcdev.dev = &pdev->dev;
> +	data->dev = &pdev->dev;
> +	idr_init(&data->idr);
> +
> +	/*clear boot flag so u84 and scpu could be reseted by software*/
> +	regmap_set_bits(data->regmap, SYSCRG_CLEAR_BOOT_INFO_OFFSET,
> +			CLEAR_BOOT_FLAG_BIT);
> +	msleep(50);
> +	platform_set_drvdata(pdev, data);

Drop, no need to do it twice.


> +
> +	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
> +}
> +
> +static void eswin_reset_remove(struct platform_device *pdev)
> +{
> +	struct eswin_reset_data *data = platform_get_drvdata(pdev);
> +
> +	idr_destroy(&data->idr);
> +}
> +
> +static struct platform_driver eswin_reset_driver = {
> +	.probe	= eswin_reset_probe,
> +	.remove = eswin_reset_remove,
> +	.driver = {
> +		.name		= "eswin-reset",
> +		.of_match_table	= eswin_reset_dt_ids,
> +	},
> +};
> +
> +static int __init eswin_reset_init(void)
> +{
> +	return platform_driver_register(&eswin_reset_driver);
> +}
> +arch_initcall(eswin_reset_init);


Best regards,
Krzysztof

[PATCH 1/2] dt-bindings: reset: eswin: Documentation for eic7700 SoC
[PATCH 2/2] reset: eswin: Add eic7700 reset driver