diff options
Diffstat (limited to 'drivers/reset/reset-starfive-jh7100.c')
-rw-r--r-- | drivers/reset/reset-starfive-jh7100.c | 173 |
1 files changed, 0 insertions, 173 deletions
diff --git a/drivers/reset/reset-starfive-jh7100.c b/drivers/reset/reset-starfive-jh7100.c deleted file mode 100644 index fc44b2fb3e03..000000000000 --- a/drivers/reset/reset-starfive-jh7100.c +++ /dev/null @@ -1,173 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Reset driver for the StarFive JH7100 SoC - * - * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk> - */ - -#include <linux/bitmap.h> -#include <linux/io.h> -#include <linux/io-64-nonatomic-lo-hi.h> -#include <linux/iopoll.h> -#include <linux/mod_devicetable.h> -#include <linux/platform_device.h> -#include <linux/reset-controller.h> -#include <linux/spinlock.h> - -#include <dt-bindings/reset/starfive-jh7100.h> - -/* register offsets */ -#define JH7100_RESET_ASSERT0 0x00 -#define JH7100_RESET_ASSERT1 0x04 -#define JH7100_RESET_ASSERT2 0x08 -#define JH7100_RESET_ASSERT3 0x0c -#define JH7100_RESET_STATUS0 0x10 -#define JH7100_RESET_STATUS1 0x14 -#define JH7100_RESET_STATUS2 0x18 -#define JH7100_RESET_STATUS3 0x1c - -/* - * Writing a 1 to the n'th bit of the m'th ASSERT register asserts - * line 32m + n, and writing a 0 deasserts the same line. - * Most reset lines have their status inverted so a 0 bit in the STATUS - * register means the line is asserted and a 1 means it's deasserted. A few - * lines don't though, so store the expected value of the status registers when - * all lines are asserted. - */ -static const u64 jh7100_reset_asserted[2] = { - /* STATUS0 */ - BIT_ULL_MASK(JH7100_RST_U74) | - BIT_ULL_MASK(JH7100_RST_VP6_DRESET) | - BIT_ULL_MASK(JH7100_RST_VP6_BRESET) | - /* STATUS1 */ - BIT_ULL_MASK(JH7100_RST_HIFI4_DRESET) | - BIT_ULL_MASK(JH7100_RST_HIFI4_BRESET), - /* STATUS2 */ - BIT_ULL_MASK(JH7100_RST_E24) | - /* STATUS3 */ - 0, -}; - -struct jh7100_reset { - struct reset_controller_dev rcdev; - /* protect registers against concurrent read-modify-write */ - spinlock_t lock; - void __iomem *base; -}; - -static inline struct jh7100_reset * -jh7100_reset_from(struct reset_controller_dev *rcdev) -{ - return container_of(rcdev, struct jh7100_reset, rcdev); -} - -static int jh7100_reset_update(struct reset_controller_dev *rcdev, - unsigned long id, bool assert) -{ - struct jh7100_reset *data = jh7100_reset_from(rcdev); - unsigned long offset = BIT_ULL_WORD(id); - u64 mask = BIT_ULL_MASK(id); - void __iomem *reg_assert = data->base + JH7100_RESET_ASSERT0 + offset * sizeof(u64); - void __iomem *reg_status = data->base + JH7100_RESET_STATUS0 + offset * sizeof(u64); - u64 done = jh7100_reset_asserted[offset] & mask; - u64 value; - unsigned long flags; - int ret; - - if (!assert) - done ^= mask; - - spin_lock_irqsave(&data->lock, flags); - - value = readq(reg_assert); - if (assert) - value |= mask; - else - value &= ~mask; - writeq(value, reg_assert); - - /* if the associated clock is gated, deasserting might otherwise hang forever */ - ret = readq_poll_timeout_atomic(reg_status, value, (value & mask) == done, 0, 1000); - - spin_unlock_irqrestore(&data->lock, flags); - return ret; -} - -static int jh7100_reset_assert(struct reset_controller_dev *rcdev, - unsigned long id) -{ - return jh7100_reset_update(rcdev, id, true); -} - -static int jh7100_reset_deassert(struct reset_controller_dev *rcdev, - unsigned long id) -{ - return jh7100_reset_update(rcdev, id, false); -} - -static int jh7100_reset_reset(struct reset_controller_dev *rcdev, - unsigned long id) -{ - int ret; - - ret = jh7100_reset_assert(rcdev, id); - if (ret) - return ret; - - return jh7100_reset_deassert(rcdev, id); -} - -static int jh7100_reset_status(struct reset_controller_dev *rcdev, - unsigned long id) -{ - struct jh7100_reset *data = jh7100_reset_from(rcdev); - unsigned long offset = BIT_ULL_WORD(id); - u64 mask = BIT_ULL_MASK(id); - void __iomem *reg_status = data->base + JH7100_RESET_STATUS0 + offset * sizeof(u64); - u64 value = readq(reg_status); - - return !((value ^ jh7100_reset_asserted[offset]) & mask); -} - -static const struct reset_control_ops jh7100_reset_ops = { - .assert = jh7100_reset_assert, - .deassert = jh7100_reset_deassert, - .reset = jh7100_reset_reset, - .status = jh7100_reset_status, -}; - -static int __init jh7100_reset_probe(struct platform_device *pdev) -{ - struct jh7100_reset *data; - - data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); - if (!data) - return -ENOMEM; - - data->base = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(data->base)) - return PTR_ERR(data->base); - - data->rcdev.ops = &jh7100_reset_ops; - data->rcdev.owner = THIS_MODULE; - data->rcdev.nr_resets = JH7100_RSTN_END; - data->rcdev.dev = &pdev->dev; - data->rcdev.of_node = pdev->dev.of_node; - spin_lock_init(&data->lock); - - return devm_reset_controller_register(&pdev->dev, &data->rcdev); -} - -static const struct of_device_id jh7100_reset_dt_ids[] = { - { .compatible = "starfive,jh7100-reset" }, - { /* sentinel */ } -}; - -static struct platform_driver jh7100_reset_driver = { - .driver = { - .name = "jh7100-reset", - .of_match_table = jh7100_reset_dt_ids, - .suppress_bind_attrs = true, - }, -}; -builtin_platform_driver_probe(jh7100_reset_driver, jh7100_reset_probe); |