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// 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");
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