diff options
author | Sean Anderson <seanga2@gmail.com> | 2020-06-24 13:41:14 +0300 |
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committer | Andes <uboot@andestech.com> | 2020-07-01 10:01:21 +0300 |
commit | 038b13ee8134ba755a323732f3b2b838b9dc17a4 (patch) | |
tree | feb3172998423931aa0bc4726a6d882d6721863b /drivers/reset/reset-syscon.c | |
parent | 082faeb86526b41bb9c5ca8373168e12f2de3a10 (diff) | |
download | u-boot-038b13ee8134ba755a323732f3b2b838b9dc17a4.tar.xz |
reset: Add generic reset driver
This patch adds a generic reset driver. It is designed to be useful when
one has a register in a regmap which contains bits that reset other
devices. I thought this seemed like a very generic use, so here is a
generic driver. The overall structure has been modeled on the syscon-reboot
driver.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'drivers/reset/reset-syscon.c')
-rw-r--r-- | drivers/reset/reset-syscon.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/reset/reset-syscon.c b/drivers/reset/reset-syscon.c new file mode 100644 index 0000000000..8520227d55 --- /dev/null +++ b/drivers/reset/reset-syscon.c @@ -0,0 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Sean Anderson + */ + +#include <common.h> +#include <dm.h> +#include <regmap.h> +#include <reset.h> +#include <reset-uclass.h> +#include <syscon.h> +#include <linux/bitops.h> +#include <linux/err.h> + +struct syscon_reset_priv { + struct regmap *regmap; + uint offset; + uint mask; + bool assert_high; +}; + +static int syscon_reset_request(struct reset_ctl *rst) +{ + struct syscon_reset_priv *priv = dev_get_priv(rst->dev); + + if (BIT(rst->id) & priv->mask) + return 0; + else + return -EINVAL; +} + +static int syscon_reset_assert(struct reset_ctl *rst) +{ + struct syscon_reset_priv *priv = dev_get_priv(rst->dev); + + return regmap_update_bits(priv->regmap, priv->offset, BIT(rst->id), + priv->assert_high ? BIT(rst->id) : 0); +} + +static int syscon_reset_deassert(struct reset_ctl *rst) +{ + struct syscon_reset_priv *priv = dev_get_priv(rst->dev); + + return regmap_update_bits(priv->regmap, priv->offset, BIT(rst->id), + priv->assert_high ? 0 : BIT(rst->id)); +} + +static const struct reset_ops syscon_reset_ops = { + .request = syscon_reset_request, + .rst_assert = syscon_reset_assert, + .rst_deassert = syscon_reset_deassert, +}; + +int syscon_reset_probe(struct udevice *dev) +{ + struct syscon_reset_priv *priv = dev_get_priv(dev); + + priv->regmap = syscon_regmap_lookup_by_phandle(dev, "regmap"); + if (IS_ERR(priv->regmap)) + return -ENODEV; + + priv->offset = dev_read_u32_default(dev, "offset", 0); + priv->mask = dev_read_u32_default(dev, "mask", 0); + priv->assert_high = dev_read_u32_default(dev, "assert-high", true); + + return 0; +} + +static const struct udevice_id syscon_reset_ids[] = { + { .compatible = "syscon-reset" }, + { }, +}; + +U_BOOT_DRIVER(syscon_reset) = { + .name = "syscon_reset", + .id = UCLASS_RESET, + .of_match = syscon_reset_ids, + .probe = syscon_reset_probe, + .priv_auto_alloc_size = sizeof(struct syscon_reset_priv), + .ops = &syscon_reset_ops, +}; |