--- /dev/null
+/*
+ * Copyright (c) 2015, Sony Mobile Communications AB.
+ * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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/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
+ * @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 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();
+ 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_fromio(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;
+ u32 orig;
+ u32 val;
+
+ spin_lock(&entry->lock);
+ val = orig = readl(entry->value);
+ val &= ~mask;
+ val |= value;
+ writel(val, entry->value);
+ spin_unlock(&entry->lock);
+
+ 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_toio(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME);
+ out->valid_entries++;
+
+ /* Make the logical entry reference the physical value */
+ entry->value = &out->entries[out->valid_entries].value;
+
+ 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);
+
+ ret = smp2p_parse_ipc(smp2p);
+ if (ret)
+ return ret;
+
+ 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 < 0) {
+ dev_err(&pdev->dev, "failed to read %s\n", key);
+ return -EINVAL;
+ }
+
+ key = "qcom,remote-pid";
+ ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->remote_pid);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to read %s\n", key);
+ return -EINVAL;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "unable to acquire smp2p interrupt\n");
+ return irq;
+ }
+
+ ret = qcom_smp2p_alloc_outbound_item(smp2p);
+ if (ret < 0)
+ return ret;
+
+ 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;
+
+ return ret;
+}
+
+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);
+
+ 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");
projects / karo-tx-linux.git / commitdiff