On 2020/12/04 19:49, Philipp Zabel wrote:
> Hi Damien,
>
> On Wed, 2020-12-02 at 12:24 +0900, Damien Le Moal wrote:
>> 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. Automatically select this driver for compilation
>> 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>
>> ---
>> MAINTAINERS | 8 +++
>> arch/riscv/Kconfig.socs | 3 +
>> drivers/reset/Kconfig | 9 +++
>> drivers/reset/Makefile | 1 +
>> drivers/reset/reset-k210.c | 141 +++++++++++++++++++++++++++++++++++++
>> 5 files changed, 162 insertions(+)
>> create mode 100644 drivers/reset/reset-k210.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index a059ab02fa8a..c2b3d6e48cd5 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -3837,6 +3837,14 @@ L: linux-gpio@xxxxxxxxxxxxxxx (pinctrl driver)
>> F: Documentation/devicetree/bindings/pinctrl/canaan,k210-fpioa.yaml
>> F: drivers/pinctrl/pinctrl-k210.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 68bdd664b5c2..b3cd253ec2c2 100644
>> --- a/arch/riscv/Kconfig.socs
>> +++ b/arch/riscv/Kconfig.socs
>> @@ -33,6 +33,9 @@ config SOC_CANAAN
>> select CLK_K210
>> select PINCTRL
>> select PINCTRL_K210
>> + select ARCH_HAS_RESET_CONTROLLER
>> + select RESET_CONTROLLER
>> + select RESET_K210
>> help
>> This enables support for Canaan Kendryte K210 SoC platform hardware.
>>
>> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
>> index 07d162b179fc..529d206cfdfd 100644
>> --- a/drivers/reset/Kconfig
>> +++ b/drivers/reset/Kconfig
>> @@ -245,6 +245,15 @@ config RESET_ZYNQ
>> help
>> This enables the reset controller driver for Xilinx Zynq SoCs.
>>
>> +config RESET_K210
>> + bool "Reset controller driver for Canaan Kendryte K210 SoC"
>> + depends on RISCV && SOC_CANAAN
>> + depends on OF && MFD_SYSCON
>> + 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.
>> +
>> source "drivers/reset/sti/Kconfig"
>> source "drivers/reset/hisilicon/Kconfig"
>> source "drivers/reset/tegra/Kconfig"
>> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
>> index 16947610cc3b..1730a31e6871 100644
>> --- a/drivers/reset/Makefile
>> +++ b/drivers/reset/Makefile
>> @@ -33,4 +33,5 @@ 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_ARCH_ZYNQMP) += reset-zynqmp.o
>> +obj-$(CONFIG_RESET_K210) += reset-k210.o
>>
>> diff --git a/drivers/reset/reset-k210.c b/drivers/reset/reset-k210.c
>> new file mode 100644
>> index 000000000000..2cf9a63c763d
>> --- /dev/null
>> +++ b/drivers/reset/reset-k210.c
>> @@ -0,0 +1,141 @@
>> +// 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);
>> + u32 bit = BIT(id);
>> +
>> + if (!(bit & K210_RST_MASK))
>> + return -EINVAL;
>
> Instead of checking this mask in the k210_rst_assert/deassert/status()
> functions, you could implement a custom .of_xlate callback and disallow
> requesting invalid resets in the first place.
OK. I did not know about this. Will look into it and send a v5.
Thanks !
>
> regards
> Philipp
>
--
Damien Le Moal
Western Digital Research
