diff options
Diffstat (limited to 'drivers/reset/reset-sunplus.c')
| -rw-r--r-- | drivers/reset/reset-sunplus.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/drivers/reset/reset-sunplus.c b/drivers/reset/reset-sunplus.c new file mode 100644 index 000000000..2f23ecaa7 --- /dev/null +++ b/drivers/reset/reset-sunplus.c @@ -0,0 +1,212 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* + * SP7021 reset driver + * + * Copyright (C) Sunplus Technology Co., Ltd. + * All rights reserved. + */ + +#include <linux/io.h> +#include <linux/init.h> +#include <linux/mod_devicetable.h> +#include <linux/platform_device.h> +#include <linux/reset-controller.h> +#include <linux/reboot.h> + +/* HIWORD_MASK_REG BITS */ +#define BITS_PER_HWM_REG 16 + +/* resets HW info: reg_index_shift */ +static const u32 sp_resets[] = { +/* SP7021: mo_reset0 ~ mo_reset9 */ + 0x00, + 0x02, + 0x03, + 0x04, + 0x05, + 0x06, + 0x07, + 0x08, + 0x09, + 0x0a, + 0x0b, + 0x0d, + 0x0e, + 0x0f, + 0x10, + 0x12, + 0x14, + 0x15, + 0x16, + 0x17, + 0x18, + 0x19, + 0x1a, + 0x1b, + 0x1c, + 0x1d, + 0x1e, + 0x1f, + 0x20, + 0x21, + 0x22, + 0x23, + 0x24, + 0x25, + 0x26, + 0x2a, + 0x2b, + 0x2d, + 0x2e, + 0x30, + 0x31, + 0x32, + 0x33, + 0x3d, + 0x3e, + 0x3f, + 0x42, + 0x44, + 0x4b, + 0x4c, + 0x4d, + 0x4e, + 0x4f, + 0x50, + 0x55, + 0x60, + 0x61, + 0x6a, + 0x6f, + 0x70, + 0x73, + 0x74, + 0x86, + 0x8a, + 0x8b, + 0x8d, + 0x8e, + 0x8f, + 0x90, + 0x92, + 0x93, + 0x94, + 0x95, + 0x96, + 0x97, + 0x98, + 0x99, +}; + +struct sp_reset { + struct reset_controller_dev rcdev; + struct notifier_block notifier; + void __iomem *base; +}; + +static inline struct sp_reset *to_sp_reset(struct reset_controller_dev *rcdev) +{ + return container_of(rcdev, struct sp_reset, rcdev); +} + +static int sp_reset_update(struct reset_controller_dev *rcdev, + unsigned long id, bool assert) +{ + struct sp_reset *reset = to_sp_reset(rcdev); + int index = sp_resets[id] / BITS_PER_HWM_REG; + int shift = sp_resets[id] % BITS_PER_HWM_REG; + u32 val; + + val = (1 << (16 + shift)) | (assert << shift); + writel(val, reset->base + (index * 4)); + + return 0; +} + +static int sp_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return sp_reset_update(rcdev, id, true); +} + +static int sp_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return sp_reset_update(rcdev, id, false); +} + +static int sp_reset_status(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct sp_reset *reset = to_sp_reset(rcdev); + int index = sp_resets[id] / BITS_PER_HWM_REG; + int shift = sp_resets[id] % BITS_PER_HWM_REG; + u32 reg; + + reg = readl(reset->base + (index * 4)); + + return !!(reg & BIT(shift)); +} + +static const struct reset_control_ops sp_reset_ops = { + .assert = sp_reset_assert, + .deassert = sp_reset_deassert, + .status = sp_reset_status, +}; + +static int sp_restart(struct notifier_block *nb, unsigned long mode, + void *cmd) +{ + struct sp_reset *reset = container_of(nb, struct sp_reset, notifier); + + sp_reset_assert(&reset->rcdev, 0); + sp_reset_deassert(&reset->rcdev, 0); + + return NOTIFY_DONE; +} + +static int sp_reset_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct sp_reset *reset; + struct resource *res; + int ret; + + reset = devm_kzalloc(dev, sizeof(*reset), GFP_KERNEL); + if (!reset) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + reset->base = devm_ioremap_resource(dev, res); + if (IS_ERR(reset->base)) + return PTR_ERR(reset->base); + + reset->rcdev.ops = &sp_reset_ops; + reset->rcdev.owner = THIS_MODULE; + reset->rcdev.of_node = dev->of_node; + reset->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_HWM_REG; + + ret = devm_reset_controller_register(dev, &reset->rcdev); + if (ret) + return ret; + + reset->notifier.notifier_call = sp_restart; + reset->notifier.priority = 192; + + return register_restart_handler(&reset->notifier); +} + +static const struct of_device_id sp_reset_dt_ids[] = { + {.compatible = "sunplus,sp7021-reset",}, + { /* sentinel */ }, +}; + +static struct platform_driver sp_reset_driver = { + .probe = sp_reset_probe, + .driver = { + .name = "sunplus-reset", + .of_match_table = sp_reset_dt_ids, + .suppress_bind_attrs = true, + }, +}; +builtin_platform_driver(sp_reset_driver); |