diff options
Diffstat (limited to 'drivers/pci/hotplug/acpiphp_ampere_altra.c')
| -rw-r--r-- | drivers/pci/hotplug/acpiphp_ampere_altra.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/acpiphp_ampere_altra.c b/drivers/pci/hotplug/acpiphp_ampere_altra.c new file mode 100644 index 000000000000..3fddd04851b6 --- /dev/null +++ b/drivers/pci/hotplug/acpiphp_ampere_altra.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ACPI PCI Hot Plug Extension for Ampere Altra. Allows control of + * attention LEDs via requests to system firmware. + * + * Copyright (C) 2023 Ampere Computing LLC + */ + +#define pr_fmt(fmt) "acpiphp_ampere_altra: " fmt + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/pci_hotplug.h> +#include <linux/platform_device.h> + +#include "acpiphp.h" + +#define HANDLE_OPEN 0xb0200000 +#define HANDLE_CLOSE 0xb0300000 +#define REQUEST 0xf0700000 +#define LED_CMD 0x00000004 +#define LED_ATTENTION 0x00000002 +#define LED_SET_ON 0x00000001 +#define LED_SET_OFF 0x00000002 +#define LED_SET_BLINK 0x00000003 + +static u32 led_service_id[4]; + +static int led_status(u8 status) +{ + switch (status) { + case 1: return LED_SET_ON; + case 2: return LED_SET_BLINK; + default: return LED_SET_OFF; + } +} + +static int set_attention_status(struct hotplug_slot *slot, u8 status) +{ + struct arm_smccc_res res; + struct pci_bus *bus; + struct pci_dev *root_port; + unsigned long flags; + u32 handle; + int ret = 0; + + bus = slot->pci_slot->bus; + root_port = pcie_find_root_port(bus->self); + if (!root_port) + return -ENODEV; + + local_irq_save(flags); + arm_smccc_smc(HANDLE_OPEN, led_service_id[0], led_service_id[1], + led_service_id[2], led_service_id[3], 0, 0, 0, &res); + if (res.a0) { + ret = -ENODEV; + goto out; + } + handle = res.a1 & 0xffff0000; + + arm_smccc_smc(REQUEST, LED_CMD, led_status(status), LED_ATTENTION, + (PCI_SLOT(root_port->devfn) << 4) | (pci_domain_nr(bus) & 0xf), + 0, 0, handle, &res); + if (res.a0) + ret = -ENODEV; + + arm_smccc_smc(HANDLE_CLOSE, handle, 0, 0, 0, 0, 0, 0, &res); + + out: + local_irq_restore(flags); + return ret; +} + +static int get_attention_status(struct hotplug_slot *slot, u8 *status) +{ + return -EINVAL; +} + +static struct acpiphp_attention_info ampere_altra_attn = { + .set_attn = set_attention_status, + .get_attn = get_attention_status, + .owner = THIS_MODULE, +}; + +static int altra_led_probe(struct platform_device *pdev) +{ + struct fwnode_handle *fwnode = dev_fwnode(&pdev->dev); + int ret; + + ret = fwnode_property_read_u32_array(fwnode, "uuid", led_service_id, 4); + if (ret) { + dev_err(&pdev->dev, "can't find uuid\n"); + return ret; + } + + ret = acpiphp_register_attention(&ere_altra_attn); + if (ret) { + dev_err(&pdev->dev, "can't register driver\n"); + return ret; + } + return 0; +} + +static void altra_led_remove(struct platform_device *pdev) +{ + acpiphp_unregister_attention(&ere_altra_attn); +} + +static const struct acpi_device_id altra_led_ids[] = { + { "AMPC0008", 0 }, + { } +}; +MODULE_DEVICE_TABLE(acpi, altra_led_ids); + +static struct platform_driver altra_led_driver = { + .driver = { + .name = "ampere-altra-leds", + .acpi_match_table = altra_led_ids, + }, + .probe = altra_led_probe, + .remove_new = altra_led_remove, +}; +module_platform_driver(altra_led_driver); + +MODULE_AUTHOR("D Scott Phillips <scott@os.amperecomputing.com>"); +MODULE_LICENSE("GPL"); |