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: Damien Le Moal <damien.lemoal@xxxxxxx> Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> --- MAINTAINERS | 8 +++ arch/riscv/Kconfig.socs | 1 + drivers/reset/Kconfig | 10 +++ drivers/reset/Makefile | 1 + drivers/reset/reset-k210.c | 131 +++++++++++++++++++++++++++++++++++++ 5 files changed, 151 insertions(+) create mode 100644 drivers/reset/reset-k210.c diff --git a/MAINTAINERS b/MAINTAINERS index 85a6a0beebd1..6059a1e4caa6 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3831,6 +3831,14 @@ 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@xxxxxxx> +L: linux-kernel@xxxxxxxxxxxxxxx +L: linux-riscv@xxxxxxxxxxxxxxxxxxx +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@xxxxxxx> L: linux-riscv@xxxxxxxxxxxxxxxxxxx diff --git a/arch/riscv/Kconfig.socs b/arch/riscv/Kconfig.socs index 88ac0d1a5da4..fdefd7eff1ae 100644 --- a/arch/riscv/Kconfig.socs +++ b/arch/riscv/Kconfig.socs @@ -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. diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 07d162b179fc..8bd4f1c34631 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -82,6 +82,16 @@ 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 diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 16947610cc3b..ef2e807721fa 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -12,6 +12,7 @@ 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 diff --git a/drivers/reset/reset-k210.c b/drivers/reset/reset-k210.c new file mode 100644 index 000000000000..1b6e03522b40 --- /dev/null +++ b/drivers/reset/reset-k210.c @@ -0,0 +1,131 @@ +// 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, ®); + 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); -- 2.29.2
