1637cee5fSGabriel Fernandez // SPDX-License-Identifier: GPL-2.0 2637cee5fSGabriel Fernandez /* 3637cee5fSGabriel Fernandez * Copyright (C) STMicroelectronics 2022 - All Rights Reserved 4637cee5fSGabriel Fernandez * Author: Gabriel Fernandez <gabriel.fernandez@foss.st.com> for STMicroelectronics. 5637cee5fSGabriel Fernandez */ 6637cee5fSGabriel Fernandez 7637cee5fSGabriel Fernandez #include <linux/of.h> 8637cee5fSGabriel Fernandez #include <linux/platform_device.h> 9637cee5fSGabriel Fernandez #include <linux/regmap.h> 10637cee5fSGabriel Fernandez #include <linux/reset-controller.h> 11637cee5fSGabriel Fernandez #include <linux/slab.h> 12637cee5fSGabriel Fernandez #include <linux/spinlock.h> 13637cee5fSGabriel Fernandez 14*30500c2aSGabriel Fernandez #include "reset-stm32.h" 15637cee5fSGabriel Fernandez 16637cee5fSGabriel Fernandez struct stm32_reset_data { 17637cee5fSGabriel Fernandez /* reset lock */ 18637cee5fSGabriel Fernandez spinlock_t lock; 19637cee5fSGabriel Fernandez struct reset_controller_dev rcdev; 20637cee5fSGabriel Fernandez void __iomem *membase; 21637cee5fSGabriel Fernandez u32 clear_offset; 22637cee5fSGabriel Fernandez }; 23637cee5fSGabriel Fernandez 24637cee5fSGabriel Fernandez static inline struct stm32_reset_data * 25637cee5fSGabriel Fernandez to_stm32_reset_data(struct reset_controller_dev *rcdev) 26637cee5fSGabriel Fernandez { 27637cee5fSGabriel Fernandez return container_of(rcdev, struct stm32_reset_data, rcdev); 28637cee5fSGabriel Fernandez } 29637cee5fSGabriel Fernandez 30637cee5fSGabriel Fernandez static int stm32_reset_update(struct reset_controller_dev *rcdev, 31637cee5fSGabriel Fernandez unsigned long id, bool assert) 32637cee5fSGabriel Fernandez { 33637cee5fSGabriel Fernandez struct stm32_reset_data *data = to_stm32_reset_data(rcdev); 34637cee5fSGabriel Fernandez int reg_width = sizeof(u32); 35637cee5fSGabriel Fernandez int bank = id / (reg_width * BITS_PER_BYTE); 36637cee5fSGabriel Fernandez int offset = id % (reg_width * BITS_PER_BYTE); 37637cee5fSGabriel Fernandez 38637cee5fSGabriel Fernandez if (data->clear_offset) { 39637cee5fSGabriel Fernandez void __iomem *addr; 40637cee5fSGabriel Fernandez 41637cee5fSGabriel Fernandez addr = data->membase + (bank * reg_width); 42637cee5fSGabriel Fernandez if (!assert) 43637cee5fSGabriel Fernandez addr += data->clear_offset; 44637cee5fSGabriel Fernandez 45637cee5fSGabriel Fernandez writel(BIT(offset), addr); 46637cee5fSGabriel Fernandez 47637cee5fSGabriel Fernandez } else { 48637cee5fSGabriel Fernandez unsigned long flags; 49637cee5fSGabriel Fernandez u32 reg; 50637cee5fSGabriel Fernandez 51637cee5fSGabriel Fernandez spin_lock_irqsave(&data->lock, flags); 52637cee5fSGabriel Fernandez 53637cee5fSGabriel Fernandez reg = readl(data->membase + (bank * reg_width)); 54637cee5fSGabriel Fernandez 55637cee5fSGabriel Fernandez if (assert) 56637cee5fSGabriel Fernandez reg |= BIT(offset); 57637cee5fSGabriel Fernandez else 58637cee5fSGabriel Fernandez reg &= ~BIT(offset); 59637cee5fSGabriel Fernandez 60637cee5fSGabriel Fernandez writel(reg, data->membase + (bank * reg_width)); 61637cee5fSGabriel Fernandez 62637cee5fSGabriel Fernandez spin_unlock_irqrestore(&data->lock, flags); 63637cee5fSGabriel Fernandez } 64637cee5fSGabriel Fernandez 65637cee5fSGabriel Fernandez return 0; 66637cee5fSGabriel Fernandez } 67637cee5fSGabriel Fernandez 68637cee5fSGabriel Fernandez static int stm32_reset_assert(struct reset_controller_dev *rcdev, 69637cee5fSGabriel Fernandez unsigned long id) 70637cee5fSGabriel Fernandez { 71637cee5fSGabriel Fernandez return stm32_reset_update(rcdev, id, true); 72637cee5fSGabriel Fernandez } 73637cee5fSGabriel Fernandez 74637cee5fSGabriel Fernandez static int stm32_reset_deassert(struct reset_controller_dev *rcdev, 75637cee5fSGabriel Fernandez unsigned long id) 76637cee5fSGabriel Fernandez { 77637cee5fSGabriel Fernandez return stm32_reset_update(rcdev, id, false); 78637cee5fSGabriel Fernandez } 79637cee5fSGabriel Fernandez 80637cee5fSGabriel Fernandez static int stm32_reset_status(struct reset_controller_dev *rcdev, 81637cee5fSGabriel Fernandez unsigned long id) 82637cee5fSGabriel Fernandez { 83637cee5fSGabriel Fernandez struct stm32_reset_data *data = to_stm32_reset_data(rcdev); 84637cee5fSGabriel Fernandez int reg_width = sizeof(u32); 85637cee5fSGabriel Fernandez int bank = id / (reg_width * BITS_PER_BYTE); 86637cee5fSGabriel Fernandez int offset = id % (reg_width * BITS_PER_BYTE); 87637cee5fSGabriel Fernandez u32 reg; 88637cee5fSGabriel Fernandez 89637cee5fSGabriel Fernandez reg = readl(data->membase + (bank * reg_width)); 90637cee5fSGabriel Fernandez 91637cee5fSGabriel Fernandez return !!(reg & BIT(offset)); 92637cee5fSGabriel Fernandez } 93637cee5fSGabriel Fernandez 94637cee5fSGabriel Fernandez static const struct reset_control_ops stm32_reset_ops = { 95637cee5fSGabriel Fernandez .assert = stm32_reset_assert, 96637cee5fSGabriel Fernandez .deassert = stm32_reset_deassert, 97637cee5fSGabriel Fernandez .status = stm32_reset_status, 98637cee5fSGabriel Fernandez }; 99637cee5fSGabriel Fernandez 100*30500c2aSGabriel Fernandez int stm32_rcc_reset_init(struct device *dev, struct clk_stm32_reset_data *data, 101637cee5fSGabriel Fernandez void __iomem *base) 102637cee5fSGabriel Fernandez { 103*30500c2aSGabriel Fernandez struct stm32_reset_data *reset_data; 104637cee5fSGabriel Fernandez 105637cee5fSGabriel Fernandez reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL); 106637cee5fSGabriel Fernandez if (!reset_data) 107637cee5fSGabriel Fernandez return -ENOMEM; 108637cee5fSGabriel Fernandez 109a1ea0857SWei Yongjun spin_lock_init(&reset_data->lock); 110*30500c2aSGabriel Fernandez 111637cee5fSGabriel Fernandez reset_data->membase = base; 112637cee5fSGabriel Fernandez reset_data->rcdev.owner = THIS_MODULE; 113637cee5fSGabriel Fernandez reset_data->rcdev.ops = &stm32_reset_ops; 114637cee5fSGabriel Fernandez reset_data->rcdev.of_node = dev_of_node(dev); 115*30500c2aSGabriel Fernandez reset_data->rcdev.nr_resets = data->nr_lines; 116637cee5fSGabriel Fernandez reset_data->clear_offset = data->clear_offset; 117637cee5fSGabriel Fernandez 118637cee5fSGabriel Fernandez return reset_controller_register(&reset_data->rcdev); 119637cee5fSGabriel Fernandez } 120