Unverified Commit 5a2308da authored by Damien Le Moal's avatar Damien Le Moal Committed by Palmer Dabbelt
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riscv: Add Canaan Kendryte K210 reset controller 



Add a reset controller driver for the Canaan Kendryte K210 SoC. This
driver relies on its syscon compatible parent node (sysctl) for its
register mapping. Default this driver compilation to y when the
SOC_CANAAN option is selected.

The MAINTAINERS file is updated, adding the entry "CANAAN/KENDRYTE K210
SOC RESET CONTROLLER DRIVER" with myself listed as maintainer for this
driver.

Signed-off-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent ed3137ed

MAINTAINERS

+8 −0
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@@ -3860,6 +3860,14 @@ W: https://github.com/Cascoda/ca8210-linux.git 
F:	Documentation/devicetree/bindings/net/ieee802154/ca8210.txt

F:	drivers/net/ieee802154/ca8210.c









CANAAN/KENDRYTE K210 SOC RESET CONTROLLER DRIVER









M:	Damien Le Moal <damien.lemoal@wdc.com>









L:	linux-kernel@vger.kernel.org









L:	linux-riscv@lists.infradead.org









S:	Maintained









F:	Documentation/devicetree/bindings/reset/canaan,k210-rst.yaml









F:	drivers/reset/reset-k210.c

















CANAAN/KENDRYTE K210 SOC SYSTEM CONTROLLER DRIVER









M:	Damien Le Moal <damien.lemoal@wdc.com>









L:	linux-riscv@lists.infradead.org
































arch/riscv/Kconfig.socs



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@@ -29,6 +29,7 @@ config SOC_CANAAN







	select SERIAL_SIFIVE if TTY









	select SERIAL_SIFIVE_CONSOLE if TTY









	select SIFIVE_PLIC









	select ARCH_HAS_RESET_CONTROLLER









	help









	  This enables support for Canaan Kendryte K210 SoC platform hardware.










































drivers/reset/Kconfig



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@@ -89,6 +89,16 @@ config RESET_INTEL_GW







	  Say Y to control the reset signals provided by reset controller.









	  Otherwise, say N.



















config RESET_K210









	bool "Reset controller driver for Canaan Kendryte K210 SoC"









	depends on (SOC_CANAAN || COMPILE_TEST) && OF









	select MFD_SYSCON









	default SOC_CANAAN









	help









	  Support for the Canaan Kendryte K210 RISC-V SoC reset controller.









	  Say Y if you want to control reset signals provided by this









	  controller.



















config RESET_LANTIQ









	bool "Lantiq XWAY Reset Driver" if COMPILE_TEST









	default SOC_TYPE_XWAY
































drivers/reset/Makefile



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@@ -13,6 +13,7 @@ obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o







obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o









obj-$(CONFIG_RESET_IMX7) += reset-imx7.o









obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o









obj-$(CONFIG_RESET_K210) += reset-k210.o









obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o









obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o









obj-$(CONFIG_RESET_MESON) += reset-meson.o
































drivers/reset/reset-k210.c
0 → 100644



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// SPDX-License-Identifier: GPL-2.0-or-later









/*









 * Copyright (c) 2020 Western Digital Corporation or its affiliates.









 */









#include <linux/of.h>









#include <linux/of_device.h>









#include <linux/platform_device.h>









#include <linux/reset-controller.h>









#include <linux/delay.h>









#include <linux/mfd/syscon.h>









#include <linux/regmap.h>









#include <soc/canaan/k210-sysctl.h>



















#include <dt-bindings/reset/k210-rst.h>



















#define K210_RST_MASK	0x27FFFFFF



















struct k210_rst {









	struct regmap *map;









	struct reset_controller_dev rcdev;









};



















static inline struct k210_rst *









to_k210_rst(struct reset_controller_dev *rcdev)









{









	return container_of(rcdev, struct k210_rst, rcdev);









}



















static inline int k210_rst_assert(struct reset_controller_dev *rcdev,









				  unsigned long id)









{









	struct k210_rst *ksr = to_k210_rst(rcdev);



















	return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 1);









}



















static inline int k210_rst_deassert(struct reset_controller_dev *rcdev,









				    unsigned long id)









{









	struct k210_rst *ksr = to_k210_rst(rcdev);



















	return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 0);









}



















static int k210_rst_reset(struct reset_controller_dev *rcdev,









			  unsigned long id)









{









	int ret;



















	ret = k210_rst_assert(rcdev, id);









	if (ret == 0) {









		udelay(10);









		ret = k210_rst_deassert(rcdev, id);









	}



















	return ret;









}



















static int k210_rst_status(struct reset_controller_dev *rcdev,









			   unsigned long id)









{









	struct k210_rst *ksr = to_k210_rst(rcdev);









	u32 reg, bit = BIT(id);









	int ret;



















	ret = regmap_read(ksr->map, K210_SYSCTL_PERI_RESET, &reg);









	if (ret)









		return ret;



















	return reg & bit;









}



















static int k210_rst_xlate(struct reset_controller_dev *rcdev,









			  const struct of_phandle_args *reset_spec)









{









	unsigned long id = reset_spec->args[0];



















	if (!(BIT(id) & K210_RST_MASK))









		return -EINVAL;



















	return id;









}



















static const struct reset_control_ops k210_rst_ops = {









	.assert		= k210_rst_assert,









	.deassert	= k210_rst_deassert,









	.reset		= k210_rst_reset,









	.status		= k210_rst_status,









};



















static int k210_rst_probe(struct platform_device *pdev)









{









	struct device *dev = &pdev->dev;









	struct device_node *parent_np = of_get_parent(dev->of_node);









	struct k210_rst *ksr;



















	dev_info(dev, "K210 reset controller\n");



















	ksr = devm_kzalloc(dev, sizeof(*ksr), GFP_KERNEL);









	if (!ksr)









		return -ENOMEM;



















	ksr->map = syscon_node_to_regmap(parent_np);









	of_node_put(parent_np);









	if (IS_ERR(ksr->map))









		return PTR_ERR(ksr->map);



















	ksr->rcdev.owner = THIS_MODULE;









	ksr->rcdev.dev = dev;









	ksr->rcdev.of_node = dev->of_node;









	ksr->rcdev.ops = &k210_rst_ops;









	ksr->rcdev.nr_resets = fls(K210_RST_MASK);









	ksr->rcdev.of_reset_n_cells = 1;









	ksr->rcdev.of_xlate = k210_rst_xlate;



















	return devm_reset_controller_register(dev, &ksr->rcdev);









}



















static const struct of_device_id k210_rst_dt_ids[] = {









	{ .compatible = "canaan,k210-rst" },









	{ /* sentinel */ },









};



















static struct platform_driver k210_rst_driver = {









	.probe	= k210_rst_probe,









	.driver = {









		.name		= "k210-rst",









		.of_match_table	= k210_rst_dt_ids,









	},









};









builtin_platform_driver(k210_rst_driver);