diff options
Diffstat (limited to 'remoteproc/ethosu_bridge_reset.c')
| -rw-r--r-- | remoteproc/ethosu_bridge_reset.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/remoteproc/ethosu_bridge_reset.c b/remoteproc/ethosu_bridge_reset.c new file mode 100644 index 0000000..7f73ee7 --- /dev/null +++ b/remoteproc/ethosu_bridge_reset.c @@ -0,0 +1,157 @@ +/* + * Copyright (c) 2021 Arm Limited. All rights reserved. + * + * This program is free software and is provided to you under the terms of the + * GNU General Public License version 2 as published by the Free Software + * Foundation, and any use by you of this program is subject to the terms + * of such GNU licence. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, you can access it online at + * http://www.gnu.org/licenses/gpl-2.0.html. + * + * SPDX-License-Identifier: GPL-2.0-only + */ + +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/reset-controller.h> + +#define ETHOSU_BRIDGE_RESET_DRIVER_VERSION "0.0.1" + +struct ethosu_reset { + struct reset_controller_dev rst; + struct device *dev; + void __iomem *base; +}; + +#define ETHOSU_BRIDGE_ID(base) (base) +#define ETHOSU_BRIDGE_CTRL(base) ((base) + 0x100) + +#define ETHOSU_BRIDGE_WAIT_ENABLE (0x2) +#define ETHOSU_BRIDGE_RESET (0x1) + +static void __iomem *bridge_verify_and_remap(struct device *dev, + struct resource *res) +{ + void __iomem *base = devm_ioremap_resource(dev, res); + u32 id; + u16 magic; + u8 minor; + u8 major; + + if (IS_ERR(base)) + return base; + + id = readl(ETHOSU_BRIDGE_ID(base)); + magic = id & 0x0000ffff; + minor = (id & 0x00ff0000) >> 16; + major = (id & 0xff000000) >> 24; + + dev_dbg(dev, "verifying bridge %d.%d", major, minor); + + if (magic != 0xBD9E) + return IOMEM_ERR_PTR(-EINVAL); + + return base; +} + +int ethosu_bridge_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct ethosu_reset *ethosu = container_of(rcdev, struct ethosu_reset, + rst); + + /* pull reset */ + dev_dbg(ethosu->dev, "Asserting reset"); + + /* set wait and reset */ + writel(ETHOSU_BRIDGE_WAIT_ENABLE | ETHOSU_BRIDGE_RESET, + ETHOSU_BRIDGE_CTRL(ethosu->base)); + + return 0; +} + +int ethosu_bridge_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct ethosu_reset *ethosu = container_of(rcdev, struct ethosu_reset, + rst); + + /* release reset */ + dev_dbg(ethosu->dev, "Deasserting reset"); + writel(~ETHOSU_BRIDGE_WAIT_ENABLE & ETHOSU_BRIDGE_RESET, + ETHOSU_BRIDGE_CTRL(ethosu->base)); + + return 0; +} + +static struct reset_control_ops ethosu_reset_bridge_ops = { + .assert = ethosu_bridge_assert, + .deassert = ethosu_bridge_deassert, +}; + +static const struct of_device_id ethosu_reset_match[] = { + { .compatible = "arm,ethosu-bridge-reset", .data = 0 }, + { /* sentinel */ }, +}; + +static int ethosu_bridge_reset_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct ethosu_reset *ethosu; + struct resource *res; + + ethosu = devm_kzalloc(&pdev->dev, sizeof(*ethosu), GFP_KERNEL); + if (!ethosu) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + ethosu->base = bridge_verify_and_remap(dev, res); + ethosu->dev = dev; + + if (IS_ERR(ethosu->base)) + return PTR_ERR(ethosu->base); + + platform_set_drvdata(pdev, ethosu); + + ethosu->rst.owner = THIS_MODULE; + ethosu->rst.nr_resets = 1; + ethosu->rst.ops = ðosu_reset_bridge_ops; + ethosu->rst.of_node = pdev->dev.of_node; + + dev_dbg(dev, "registering to reset controller core"); + + return devm_reset_controller_register(dev, ðosu->rst); +} + +static int ethosu_bridge_reset_remove(struct platform_device *pdev) +{ + return 0; +} + +static struct platform_driver ethosu_reset_driver = { + .probe = ethosu_bridge_reset_probe, + .remove = ethosu_bridge_reset_remove, + .driver = { + .name = "ethosu-bridge-reset", + .of_match_table = of_match_ptr(ethosu_reset_match), + }, +}; + +module_platform_driver(ethosu_reset_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Arm Ltd"); +MODULE_DESCRIPTION("Arm Ethos-U NPU Bridge Reset Driver"); +MODULE_VERSION(ETHOSU_BRIDGE_RESET_DRIVER_VERSION); |