1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * ARM APMT table support.
  4 * Design document number: ARM DEN0117.
  5 *
  6 * Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES.
  7 *
  8 */
  9
 10#define pr_fmt(fmt)	"ACPI: APMT: " fmt
 11
 12#include <linux/acpi.h>
 13#include <linux/init.h>
 14#include <linux/kernel.h>
 15#include <linux/platform_device.h>
 16#include "init.h"
 17
 18#define DEV_NAME "arm-cs-arch-pmu"
 19
 20/* There can be up to 3 resources: page 0 and 1 address, and interrupt. */
 21#define DEV_MAX_RESOURCE_COUNT 3
 22
 23/* Root pointer to the mapped APMT table */
 24static struct acpi_table_header *apmt_table;
 25
 26static int __init apmt_init_resources(struct resource *res,
 27				      struct acpi_apmt_node *node)
 28{
 29	int irq, trigger;
 30	int num_res = 0;
 31
 32	res[num_res].start = node->base_address0;
 33	res[num_res].end = node->base_address0 + SZ_4K - 1;
 34	res[num_res].flags = IORESOURCE_MEM;
 35
 36	num_res++;
 37
 38	if (node->flags & ACPI_APMT_FLAGS_DUAL_PAGE) {
 39		res[num_res].start = node->base_address1;
 40		res[num_res].end = node->base_address1 + SZ_4K - 1;
 41		res[num_res].flags = IORESOURCE_MEM;
 42
 43		num_res++;
 44	}
 45
 46	if (node->ovflw_irq != 0) {
 47		trigger = (node->ovflw_irq_flags & ACPI_APMT_OVFLW_IRQ_FLAGS_MODE);
 48		trigger = (trigger == ACPI_APMT_OVFLW_IRQ_FLAGS_MODE_LEVEL) ?
 49			ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
 50		irq = acpi_register_gsi(NULL, node->ovflw_irq, trigger,
 51						ACPI_ACTIVE_HIGH);
 52
 53		if (irq <= 0) {
 54			pr_warn("APMT could not register gsi hwirq %d\n", irq);
 55			return num_res;
 56		}
 57
 58		res[num_res].start = irq;
 59		res[num_res].end = irq;
 60		res[num_res].flags = IORESOURCE_IRQ;
 61
 62		num_res++;
 63	}
 64
 65	return num_res;
 66}
 67
 68/**
 69 * apmt_add_platform_device() - Allocate a platform device for APMT node
 70 * @node: Pointer to device ACPI APMT node
 71 * @fwnode: fwnode associated with the APMT node
 72 *
 73 * Returns: 0 on success, <0 failure
 74 */
 75static int __init apmt_add_platform_device(struct acpi_apmt_node *node,
 76					   struct fwnode_handle *fwnode)
 77{
 78	struct platform_device *pdev;
 79	int ret, count;
 80	struct resource res[DEV_MAX_RESOURCE_COUNT];
 81
 82	pdev = platform_device_alloc(DEV_NAME, PLATFORM_DEVID_AUTO);
 83	if (!pdev)
 84		return -ENOMEM;
 85
 86	memset(res, 0, sizeof(res));
 87
 88	count = apmt_init_resources(res, node);
 89
 90	ret = platform_device_add_resources(pdev, res, count);
 91	if (ret)
 92		goto dev_put;
 93
 94	/*
 95	 * Add a copy of APMT node pointer to platform_data to be used to
 96	 * retrieve APMT data information.
 97	 */
 98	ret = platform_device_add_data(pdev, &node, sizeof(node));
 99	if (ret)
100		goto dev_put;
101
102	pdev->dev.fwnode = fwnode;
103
104	ret = platform_device_add(pdev);
105
106	if (ret)
107		goto dev_put;
108
109	return 0;
110
111dev_put:
112	platform_device_put(pdev);
113
114	return ret;
115}
116
117static int __init apmt_init_platform_devices(void)
118{
119	struct acpi_apmt_node *apmt_node;
120	struct acpi_table_apmt *apmt;
121	struct fwnode_handle *fwnode;
122	u64 offset, end;
123	int ret;
124
125	/*
126	 * apmt_table and apmt both point to the start of APMT table, but
127	 * have different struct types
128	 */
129	apmt = (struct acpi_table_apmt *)apmt_table;
130	offset = sizeof(*apmt);
131	end = apmt->header.length;
132
133	while (offset < end) {
134		apmt_node = ACPI_ADD_PTR(struct acpi_apmt_node, apmt,
135				 offset);
136
137		fwnode = acpi_alloc_fwnode_static();
138		if (!fwnode)
139			return -ENOMEM;
140
141		ret = apmt_add_platform_device(apmt_node, fwnode);
142		if (ret) {
143			acpi_free_fwnode_static(fwnode);
144			return ret;
145		}
146
147		offset += apmt_node->length;
148	}
149
150	return 0;
151}
152
153void __init acpi_apmt_init(void)
154{
155	acpi_status status;
156	int ret;
157
158	/**
159	 * APMT table nodes will be used at runtime after the apmt init,
160	 * so we don't need to call acpi_put_table() to release
161	 * the APMT table mapping.
162	 */
163	status = acpi_get_table(ACPI_SIG_APMT, 0, &apmt_table);
164
165	if (ACPI_FAILURE(status)) {
166		if (status != AE_NOT_FOUND) {
167			const char *msg = acpi_format_exception(status);
168
169			pr_err("Failed to get APMT table, %s\n", msg);
170		}
171
172		return;
173	}
174
175	ret = apmt_init_platform_devices();
176	if (ret) {
177		pr_err("Failed to initialize APMT platform devices, ret: %d\n", ret);
178		acpi_put_table(apmt_table);
179	}
180}