drivers/reset/reset-raspberrypi.c

1 // SPDX-License-Identifier: GPL-2.0
3  * Raspberry Pi 4 firmware reset driver
12 #include <linux/reset-controller.h>
13 #include <soc/bcm2835/raspberrypi-firmware.h>
14 #include <dt-bindings/reset/raspberrypi,firmware-reset.h>
36 		 * PCIe chip that implements xHCI. After a PCI reset, VL805's  in rpi_reset_reset()
37 		 * firmware may either be loaded directly from an EEPROM or, if  in rpi_reset_reset()
38 		 * not present, by the SoC's co-processor, VideoCore. rpi's  in rpi_reset_reset()
39 		 * VideoCore OS contains both the non public firmware load  in rpi_reset_reset()
40 		 * logic and the VL805 firmware blob. This triggers the  in rpi_reset_reset()
44 		 * firmware encoded like this:  in rpi_reset_reset()
52 		ret = rpi_firmware_property(priv->fw, RPI_FIRMWARE_NOTIFY_XHCI_RESET,  in rpi_reset_reset()
62 		return -EINVAL;  in rpi_reset_reset()
69 	.reset	= rpi_reset_reset,
74 	struct device *dev = &pdev->dev;  in rpi_reset_probe()
79 	np = of_get_parent(dev->of_node);  in rpi_reset_probe()
81 		dev_err(dev, "Missing firmware node\n");  in rpi_reset_probe()
82 		return -ENOENT;  in rpi_reset_probe()
85 	fw = devm_rpi_firmware_get(&pdev->dev, np);  in rpi_reset_probe()
88 		return -EPROBE_DEFER;  in rpi_reset_probe()
92 		return -ENOMEM;  in rpi_reset_probe()
96 	priv->fw = fw;  in rpi_reset_probe()
97 	priv->rcdev.owner = THIS_MODULE;  in rpi_reset_probe()
98 	priv->rcdev.nr_resets = RASPBERRYPI_FIRMWARE_RESET_NUM_IDS;  in rpi_reset_probe()
99 	priv->rcdev.ops = &rpi_reset_ops;  in rpi_reset_probe()
100 	priv->rcdev.of_node = dev->of_node;  in rpi_reset_probe()
102 	return devm_reset_controller_register(dev, &priv->rcdev);  in rpi_reset_probe()
106 	{ .compatible = "raspberrypi,firmware-reset" },
114 		.name = "raspberrypi-reset",
121 MODULE_DESCRIPTION("Raspberry Pi 4 firmware reset driver");