Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015, Sony Mobile Communications AB.
 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
 */
 
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/mailbox_client.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/soc/qcom/smem.h>
#include <linux/soc/qcom/smem_state.h>
#include <linux/spinlock.h>
 
/*
 * The Shared Memory Point to Point (SMP2P) protocol facilitates communication
 * of a single 32-bit value between two processors.  Each value has a single
 * writer (the local side) and a single reader (the remote side). Values are
 * uniquely identified in the system by the directed edge (local processor ID
 * to remote processor ID) and a string identifier.
 *
 * Each processor is responsible for creating the outgoing SMEM items and each
 * item is writable by the local processor and readable by the remote
 * processor.  By using two separate SMEM items that are single-reader and
 * single-writer, SMP2P does not require any remote locking mechanisms.
 *
 * The driver uses the Linux GPIO and interrupt framework to expose a virtual
 * GPIO for each outbound entry and a virtual interrupt controller for each
 * inbound entry.
 */
 
#define SMP2P_MAX_ENTRY 16
#define SMP2P_MAX_ENTRY_NAME 16
 
#define SMP2P_FEATURE_SSR_ACK 0x1
 
#define SMP2P_MAGIC 0x504d5324
 
/**
 * struct smp2p_smem_item - in memory communication structure
 * @magic:		magic number
 * @version:		version - must be 1
 * @features:		features flag - currently unused
 * @local_pid:		processor id of sending end
 * @remote_pid:		processor id of receiving end
 * @total_entries:	number of entries - always SMP2P_MAX_ENTRY
 * @valid_entries:	number of allocated entries
 * @flags:
 * @entries:		individual communication entries
 *     @name:		name of the entry
 *     @value:		content of the entry
 */
struct smp2p_smem_item {
<------>u32 magic;
<------>u8 version;
<------>unsigned features:24;
<------>u16 local_pid;
<------>u16 remote_pid;
<------>u16 total_entries;
<------>u16 valid_entries;
<------>u32 flags;
 
<------>struct {
<------><------>u8 name[SMP2P_MAX_ENTRY_NAME];
<------><------>u32 value;
<------>} entries[SMP2P_MAX_ENTRY];
} __packed;
 
/**
 * struct smp2p_entry - driver context matching one entry
 * @node:	list entry to keep track of allocated entries
 * @smp2p:	reference to the device driver context
 * @name:	name of the entry, to match against smp2p_smem_item
 * @value:	pointer to smp2p_smem_item entry value
 * @last_value:	last handled value
 * @domain:	irq_domain for inbound entries
 * @irq_enabled:bitmap to track enabled irq bits
 * @irq_rising:	bitmap to mark irq bits for rising detection
 * @irq_falling:bitmap to mark irq bits for falling detection
 * @state:	smem state handle
 * @lock:	spinlock to protect read-modify-write of the value
 */
struct smp2p_entry {
<------>struct list_head node;
<------>struct qcom_smp2p *smp2p;
 
<------>const char *name;
<------>u32 *value;
<------>u32 last_value;
 
<------>struct irq_domain *domain;
<------>DECLARE_BITMAP(irq_enabled, 32);
<------>DECLARE_BITMAP(irq_rising, 32);
<------>DECLARE_BITMAP(irq_falling, 32);
 
<------>struct qcom_smem_state *state;
 
<------>spinlock_t lock;
};
 
#define SMP2P_INBOUND	0
#define SMP2P_OUTBOUND	1
 
/**
 * struct qcom_smp2p - device driver context
 * @dev:	device driver handle
 * @in:		pointer to the inbound smem item
 * @smem_items:	ids of the two smem items
 * @valid_entries: already scanned inbound entries
 * @local_pid:	processor id of the inbound edge
 * @remote_pid:	processor id of the outbound edge
 * @ipc_regmap:	regmap for the outbound ipc
 * @ipc_offset:	offset within the regmap
 * @ipc_bit:	bit in regmap@offset to kick to signal remote processor
 * @mbox_client: mailbox client handle
 * @mbox_chan:	apcs ipc mailbox channel handle
 * @inbound:	list of inbound entries
 * @outbound:	list of outbound entries
 */
struct qcom_smp2p {
<------>struct device *dev;
 
<------>struct smp2p_smem_item *in;
<------>struct smp2p_smem_item *out;
 
<------>unsigned smem_items[SMP2P_OUTBOUND + 1];
 
<------>unsigned valid_entries;
 
<------>unsigned local_pid;
<------>unsigned remote_pid;
 
<------>struct regmap *ipc_regmap;
<------>int ipc_offset;
<------>int ipc_bit;
 
<------>struct mbox_client mbox_client;
<------>struct mbox_chan *mbox_chan;
 
<------>struct list_head inbound;
<------>struct list_head outbound;
};
 
static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
{
<------>/* Make sure any updated data is written before the kick */
<------>wmb();
 
<------>if (smp2p->mbox_chan) {
<------><------>mbox_send_message(smp2p->mbox_chan, NULL);
<------><------>mbox_client_txdone(smp2p->mbox_chan, 0);
<------>} else {
<------><------>regmap_write(smp2p->ipc_regmap, smp2p->ipc_offset, BIT(smp2p->ipc_bit));
<------>}
}
 
/**
 * qcom_smp2p_intr() - interrupt handler for incoming notifications
 * @irq:	unused
 * @data:	smp2p driver context
 *
 * Handle notifications from the remote side to handle newly allocated entries
 * or any changes to the state bits of existing entries.
 */
static irqreturn_t qcom_smp2p_intr(int irq, void *data)
{
<------>struct smp2p_smem_item *in;
<------>struct smp2p_entry *entry;
<------>struct qcom_smp2p *smp2p = data;
<------>unsigned smem_id = smp2p->smem_items[SMP2P_INBOUND];
<------>unsigned pid = smp2p->remote_pid;
<------>size_t size;
<------>int irq_pin;
<------>u32 status;
<------>char buf[SMP2P_MAX_ENTRY_NAME];
<------>u32 val;
<------>int i;
 
<------>in = smp2p->in;
 
<------>/* Acquire smem item, if not already found */
<------>if (!in) {
<------><------>in = qcom_smem_get(pid, smem_id, &size);
<------><------>if (IS_ERR(in)) {
<------><------><------>dev_err(smp2p->dev,
<------><------><------><------>"Unable to acquire remote smp2p item\n");
<------><------><------>return IRQ_HANDLED;
<------><------>}
 
<------><------>smp2p->in = in;
<------>}
 
<------>/* Match newly created entries */
<------>for (i = smp2p->valid_entries; i < in->valid_entries; i++) {
<------><------>list_for_each_entry(entry, &smp2p->inbound, node) {
<------><------><------>memcpy(buf, in->entries[i].name, sizeof(buf));
<------><------><------>if (!strcmp(buf, entry->name)) {
<------><------><------><------>entry->value = &in->entries[i].value;
<------><------><------><------>break;
<------><------><------>}
<------><------>}
<------>}
<------>smp2p->valid_entries = i;
 
<------>/* Fire interrupts based on any value changes */
<------>list_for_each_entry(entry, &smp2p->inbound, node) {
<------><------>/* Ignore entries not yet allocated by the remote side */
<------><------>if (!entry->value)
<------><------><------>continue;
 
<------><------>val = readl(entry->value);
 
<------><------>status = val ^ entry->last_value;
<------><------>entry->last_value = val;
 
<------><------>/* No changes of this entry? */
<------><------>if (!status)
<------><------><------>continue;
 
<------><------>for_each_set_bit(i, entry->irq_enabled, 32) {
<------><------><------>if (!(status & BIT(i)))
<------><------><------><------>continue;
 
<------><------><------>if ((val & BIT(i) && test_bit(i, entry->irq_rising)) ||
<------><------><------>    (!(val & BIT(i)) && test_bit(i, entry->irq_falling))) {
<------><------><------><------>irq_pin = irq_find_mapping(entry->domain, i);
<------><------><------><------>handle_nested_irq(irq_pin);
<------><------><------>}
<------><------>}
<------>}
 
<------>return IRQ_HANDLED;
}
 
static void smp2p_mask_irq(struct irq_data *irqd)
{
<------>struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
<------>irq_hw_number_t irq = irqd_to_hwirq(irqd);
 
<------>clear_bit(irq, entry->irq_enabled);
}
 
static void smp2p_unmask_irq(struct irq_data *irqd)
{
<------>struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
<------>irq_hw_number_t irq = irqd_to_hwirq(irqd);
 
<------>set_bit(irq, entry->irq_enabled);
}
 
static int smp2p_set_irq_type(struct irq_data *irqd, unsigned int type)
{
<------>struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
<------>irq_hw_number_t irq = irqd_to_hwirq(irqd);
 
<------>if (!(type & IRQ_TYPE_EDGE_BOTH))
<------><------>return -EINVAL;
 
<------>if (type & IRQ_TYPE_EDGE_RISING)
<------><------>set_bit(irq, entry->irq_rising);
<------>else
<------><------>clear_bit(irq, entry->irq_rising);
 
<------>if (type & IRQ_TYPE_EDGE_FALLING)
<------><------>set_bit(irq, entry->irq_falling);
<------>else
<------><------>clear_bit(irq, entry->irq_falling);
 
<------>return 0;
}
 
static struct irq_chip smp2p_irq_chip = {
<------>.name           = "smp2p",
<------>.irq_mask       = smp2p_mask_irq,
<------>.irq_unmask     = smp2p_unmask_irq,
<------>.irq_set_type	= smp2p_set_irq_type,
};
 
static int smp2p_irq_map(struct irq_domain *d,
<------><------><------> unsigned int irq,
<------><------><------> irq_hw_number_t hw)
{
<------>struct smp2p_entry *entry = d->host_data;
 
<------>irq_set_chip_and_handler(irq, &smp2p_irq_chip, handle_level_irq);
<------>irq_set_chip_data(irq, entry);
<------>irq_set_nested_thread(irq, 1);
<------>irq_set_noprobe(irq);
 
<------>return 0;
}
 
static const struct irq_domain_ops smp2p_irq_ops = {
<------>.map = smp2p_irq_map,
<------>.xlate = irq_domain_xlate_twocell,
};
 
static int qcom_smp2p_inbound_entry(struct qcom_smp2p *smp2p,
<------><------><------><------>    struct smp2p_entry *entry,
<------><------><------><------>    struct device_node *node)
{
<------>entry->domain = irq_domain_add_linear(node, 32, &smp2p_irq_ops, entry);
<------>if (!entry->domain) {
<------><------>dev_err(smp2p->dev, "failed to add irq_domain\n");
<------><------>return -ENOMEM;
<------>}
 
<------>return 0;
}
 
static int smp2p_update_bits(void *data, u32 mask, u32 value)
{
<------>struct smp2p_entry *entry = data;
<------>unsigned long flags;
<------>u32 orig;
<------>u32 val;
 
<------>spin_lock_irqsave(&entry->lock, flags);
<------>val = orig = readl(entry->value);
<------>val &= ~mask;
<------>val |= value;
<------>writel(val, entry->value);
<------>spin_unlock_irqrestore(&entry->lock, flags);
 
<------>if (val != orig)
<------><------>qcom_smp2p_kick(entry->smp2p);
 
<------>return 0;
}
 
static const struct qcom_smem_state_ops smp2p_state_ops = {
<------>.update_bits = smp2p_update_bits,
};
 
static int qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p,
<------><------><------><------>     struct smp2p_entry *entry,
<------><------><------><------>     struct device_node *node)
{
<------>struct smp2p_smem_item *out = smp2p->out;
<------>char buf[SMP2P_MAX_ENTRY_NAME] = {};
 
<------>/* Allocate an entry from the smem item */
<------>strlcpy(buf, entry->name, SMP2P_MAX_ENTRY_NAME);
<------>memcpy(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME);
 
<------>/* Make the logical entry reference the physical value */
<------>entry->value = &out->entries[out->valid_entries].value;
 
<------>out->valid_entries++;
 
<------>entry->state = qcom_smem_state_register(node, &smp2p_state_ops, entry);
<------>if (IS_ERR(entry->state)) {
<------><------>dev_err(smp2p->dev, "failed to register qcom_smem_state\n");
<------><------>return PTR_ERR(entry->state);
<------>}
 
<------>return 0;
}
 
static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
{
<------>struct smp2p_smem_item *out;
<------>unsigned smem_id = smp2p->smem_items[SMP2P_OUTBOUND];
<------>unsigned pid = smp2p->remote_pid;
<------>int ret;
 
<------>ret = qcom_smem_alloc(pid, smem_id, sizeof(*out));
<------>if (ret < 0 && ret != -EEXIST) {
<------><------>if (ret != -EPROBE_DEFER)
<------><------><------>dev_err(smp2p->dev,
<------><------><------><------>"unable to allocate local smp2p item\n");
<------><------>return ret;
<------>}
 
<------>out = qcom_smem_get(pid, smem_id, NULL);
<------>if (IS_ERR(out)) {
<------><------>dev_err(smp2p->dev, "Unable to acquire local smp2p item\n");
<------><------>return PTR_ERR(out);
<------>}
 
<------>memset(out, 0, sizeof(*out));
<------>out->magic = SMP2P_MAGIC;
<------>out->local_pid = smp2p->local_pid;
<------>out->remote_pid = smp2p->remote_pid;
<------>out->total_entries = SMP2P_MAX_ENTRY;
<------>out->valid_entries = 0;
 
<------>/*
<------> * Make sure the rest of the header is written before we validate the
<------> * item by writing a valid version number.
<------> */
<------>wmb();
<------>out->version = 1;
 
<------>qcom_smp2p_kick(smp2p);
 
<------>smp2p->out = out;
 
<------>return 0;
}
 
static int smp2p_parse_ipc(struct qcom_smp2p *smp2p)
{
<------>struct device_node *syscon;
<------>struct device *dev = smp2p->dev;
<------>const char *key;
<------>int ret;
 
<------>syscon = of_parse_phandle(dev->of_node, "qcom,ipc", 0);
<------>if (!syscon) {
<------><------>dev_err(dev, "no qcom,ipc node\n");
<------><------>return -ENODEV;
<------>}
 
<------>smp2p->ipc_regmap = syscon_node_to_regmap(syscon);
<------>if (IS_ERR(smp2p->ipc_regmap))
<------><------>return PTR_ERR(smp2p->ipc_regmap);
 
<------>key = "qcom,ipc";
<------>ret = of_property_read_u32_index(dev->of_node, key, 1, &smp2p->ipc_offset);
<------>if (ret < 0) {
<------><------>dev_err(dev, "no offset in %s\n", key);
<------><------>return -EINVAL;
<------>}
 
<------>ret = of_property_read_u32_index(dev->of_node, key, 2, &smp2p->ipc_bit);
<------>if (ret < 0) {
<------><------>dev_err(dev, "no bit in %s\n", key);
<------><------>return -EINVAL;
<------>}
 
<------>return 0;
}
 
static int qcom_smp2p_probe(struct platform_device *pdev)
{
<------>struct smp2p_entry *entry;
<------>struct device_node *node;
<------>struct qcom_smp2p *smp2p;
<------>const char *key;
<------>int irq;
<------>int ret;
 
<------>smp2p = devm_kzalloc(&pdev->dev, sizeof(*smp2p), GFP_KERNEL);
<------>if (!smp2p)
<------><------>return -ENOMEM;
 
<------>smp2p->dev = &pdev->dev;
<------>INIT_LIST_HEAD(&smp2p->inbound);
<------>INIT_LIST_HEAD(&smp2p->outbound);
 
<------>platform_set_drvdata(pdev, smp2p);
 
<------>key = "qcom,smem";
<------>ret = of_property_read_u32_array(pdev->dev.of_node, key,
<------><------><------><------><------> smp2p->smem_items, 2);
<------>if (ret)
<------><------>return ret;
 
<------>key = "qcom,local-pid";
<------>ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->local_pid);
<------>if (ret)
<------><------>goto report_read_failure;
 
<------>key = "qcom,remote-pid";
<------>ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->remote_pid);
<------>if (ret)
<------><------>goto report_read_failure;
 
<------>irq = platform_get_irq(pdev, 0);
<------>if (irq < 0)
<------><------>return irq;
 
<------>smp2p->mbox_client.dev = &pdev->dev;
<------>smp2p->mbox_client.knows_txdone = true;
<------>smp2p->mbox_chan = mbox_request_channel(&smp2p->mbox_client, 0);
<------>if (IS_ERR(smp2p->mbox_chan)) {
<------><------>if (PTR_ERR(smp2p->mbox_chan) != -ENODEV)
<------><------><------>return PTR_ERR(smp2p->mbox_chan);
 
<------><------>smp2p->mbox_chan = NULL;
 
<------><------>ret = smp2p_parse_ipc(smp2p);
<------><------>if (ret)
<------><------><------>return ret;
<------>}
 
<------>ret = qcom_smp2p_alloc_outbound_item(smp2p);
<------>if (ret < 0)
<------><------>goto release_mbox;
 
<------>for_each_available_child_of_node(pdev->dev.of_node, node) {
<------><------>entry = devm_kzalloc(&pdev->dev, sizeof(*entry), GFP_KERNEL);
<------><------>if (!entry) {
<------><------><------>ret = -ENOMEM;
<------><------><------>goto unwind_interfaces;
<------><------>}
 
<------><------>entry->smp2p = smp2p;
<------><------>spin_lock_init(&entry->lock);
 
<------><------>ret = of_property_read_string(node, "qcom,entry-name", &entry->name);
<------><------>if (ret < 0)
<------><------><------>goto unwind_interfaces;
 
<------><------>if (of_property_read_bool(node, "interrupt-controller")) {
<------><------><------>ret = qcom_smp2p_inbound_entry(smp2p, entry, node);
<------><------><------>if (ret < 0)
<------><------><------><------>goto unwind_interfaces;
 
<------><------><------>list_add(&entry->node, &smp2p->inbound);
<------><------>} else  {
<------><------><------>ret = qcom_smp2p_outbound_entry(smp2p, entry, node);
<------><------><------>if (ret < 0)
<------><------><------><------>goto unwind_interfaces;
 
<------><------><------>list_add(&entry->node, &smp2p->outbound);
<------><------>}
<------>}
 
<------>/* Kick the outgoing edge after allocating entries */
<------>qcom_smp2p_kick(smp2p);
 
<------>ret = devm_request_threaded_irq(&pdev->dev, irq,
<------><------><------><------><------>NULL, qcom_smp2p_intr,
<------><------><------><------><------>IRQF_ONESHOT,
<------><------><------><------><------>"smp2p", (void *)smp2p);
<------>if (ret) {
<------><------>dev_err(&pdev->dev, "failed to request interrupt\n");
<------><------>goto unwind_interfaces;
<------>}
 
 
<------>return 0;
 
unwind_interfaces:
<------>list_for_each_entry(entry, &smp2p->inbound, node)
<------><------>irq_domain_remove(entry->domain);
 
<------>list_for_each_entry(entry, &smp2p->outbound, node)
<------><------>qcom_smem_state_unregister(entry->state);
 
<------>smp2p->out->valid_entries = 0;
 
release_mbox:
<------>mbox_free_channel(smp2p->mbox_chan);
 
<------>return ret;
 
report_read_failure:
<------>dev_err(&pdev->dev, "failed to read %s\n", key);
<------>return -EINVAL;
}
 
static int qcom_smp2p_remove(struct platform_device *pdev)
{
<------>struct qcom_smp2p *smp2p = platform_get_drvdata(pdev);
<------>struct smp2p_entry *entry;
 
<------>list_for_each_entry(entry, &smp2p->inbound, node)
<------><------>irq_domain_remove(entry->domain);
 
<------>list_for_each_entry(entry, &smp2p->outbound, node)
<------><------>qcom_smem_state_unregister(entry->state);
 
<------>mbox_free_channel(smp2p->mbox_chan);
 
<------>smp2p->out->valid_entries = 0;
 
<------>return 0;
}
 
static const struct of_device_id qcom_smp2p_of_match[] = {
<------>{ .compatible = "qcom,smp2p" },
<------>{}
};
MODULE_DEVICE_TABLE(of, qcom_smp2p_of_match);
 
static struct platform_driver qcom_smp2p_driver = {
<------>.probe = qcom_smp2p_probe,
<------>.remove = qcom_smp2p_remove,
<------>.driver  = {
<------><------>.name  = "qcom_smp2p",
<------><------>.of_match_table = qcom_smp2p_of_match,
<------>},
};
module_platform_driver(qcom_smp2p_driver);
 
MODULE_DESCRIPTION("Qualcomm Shared Memory Point to Point driver");
MODULE_LICENSE("GPL v2");