diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index caf1dc9..048f208 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -21,4 +21,9 @@ help This enables the reset controller driver for i.MX7 SoCs. +config RESET_STM32 + bool "STM32 Reset Driver" + help + This enables the reset controller driver for STM32MP and STM32 MCUs. + endif diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 0b55caa..8460c4b 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -1,3 +1,4 @@ obj-$(CONFIG_RESET_CONTROLLER) += core.o obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o obj-$(CONFIG_RESET_IMX7) += reset-imx7.o +obj-$(CONFIG_RESET_STM32) += reset-stm32.o diff --git a/drivers/reset/reset-stm32.c b/drivers/reset/reset-stm32.c new file mode 100644 index 0000000..5689dfd --- /dev/null +++ b/drivers/reset/reset-stm32.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved + * Copyright (C) 2019, Ahmad Fatoum, Pengutronix + * Author(s): Patrice Chotard, for STMicroelectronics. + */ + +#include +#include +#include +#include +#include + +#define RCC_CL 0x4 + +struct stm32_reset { + void __iomem *base; + struct reset_controller_dev rcdev; + void (*reset)(void __iomem *reg, unsigned offset, bool assert); +}; + +static struct stm32_reset *to_stm32_reset(struct reset_controller_dev *rcdev) +{ + return container_of(rcdev, struct stm32_reset, rcdev); +} + +static void stm32mp_reset(void __iomem *reg, unsigned offset, bool assert) +{ + if (!assert) + reg += RCC_CL; + + writel(BIT(offset), reg); +} + +static void stm32mcu_reset(void __iomem *reg, unsigned offset, bool assert) +{ + if (assert) + setbits_le32(reg, BIT(offset)); + else + clrbits_le32(reg, BIT(offset)); +} + +static void stm32_reset(struct stm32_reset *priv, unsigned long id, bool assert) +{ + int bank = (id / BITS_PER_LONG) * 4; + int offset = id % BITS_PER_LONG; + + priv->reset(priv->base + bank, offset, assert); +} + +static int stm32_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + stm32_reset(to_stm32_reset(rcdev), id, true); + return 0; +} + +static int stm32_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + stm32_reset(to_stm32_reset(rcdev), id, false); + return 0; +} + +static const struct reset_control_ops stm32_reset_ops = { + .assert = stm32_reset_assert, + .deassert = stm32_reset_deassert, +}; + +static int stm32_reset_probe(struct device_d *dev) +{ + struct stm32_reset *priv; + struct resource *iores; + int ret; + + priv = xzalloc(sizeof(*priv)); + ret = dev_get_drvdata(dev, (const void **)&priv->reset); + if (ret) + return ret; + + iores = dev_request_mem_resource(dev, 0); + if (IS_ERR(iores)) + return PTR_ERR(iores); + + priv->base = IOMEM(iores->start); + priv->rcdev.nr_resets = (iores->end - iores->start) * BITS_PER_BYTE; + priv->rcdev.ops = &stm32_reset_ops; + priv->rcdev.of_node = dev->device_node; + + return reset_controller_register(&priv->rcdev); +} + +static const struct of_device_id stm32_rcc_reset_dt_ids[] = { + { .compatible = "st,stm32mp1-rcc", .data = stm32mp_reset }, + { .compatible = "st,stm32-rcc", .data = stm32mcu_reset }, + { /* sentinel */ }, +}; + +static struct driver_d stm32_rcc_reset_driver = { + .name = "stm32_rcc_reset", + .probe = stm32_reset_probe, + .of_compatible = DRV_OF_COMPAT(stm32_rcc_reset_dt_ids), +}; + +static int stm32_rcc_reset_init(void) +{ + return platform_driver_register(&stm32_rcc_reset_driver); +} +postcore_initcall(stm32_rcc_reset_init);