-/*
- * 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/module.h>
-#include <linux/platform_device.h>
-#include <linux/of_platform.h>
-#include <linux/io.h>
-#include <linux/interrupt.h>
-#include <linux/memblock.h>
-#include <linux/slab.h>
-#include <linux/of_address.h>
-#include <linux/of_irq.h>
-#include <linux/regmap.h>
-#include <linux/list.h>
-#include <linux/gpio.h>
-#include <linux/mfd/syscon.h>
-
-#include <linux/delay.h>
-
-#include <linux/soc/qcom/smem.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
- * @chip: gpio_chip for outbound entries
- */
-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 gpio_chip chip;
-};
-
-#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));
-}
-
-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;
- u32 val;
- int i;
- u8 tmp_name[SMP2P_MAX_ENTRY_NAME];
-
- 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(tmp_name, in->entries[i].name,
- SMP2P_MAX_ENTRY_NAME);
- if (!strcmp(tmp_name, 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 = *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)) {
- if (test_bit(i, entry->irq_rising)) {
- irq_pin = irq_find_mapping(entry->domain, i);
- handle_nested_irq(irq_pin);
- }
- } else {
- if (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 smp2p_gpio_direction_output(struct gpio_chip *chip,
- unsigned offset,
- int value)
-{
- struct smp2p_entry *entry = container_of(chip, struct smp2p_entry, chip);
-
- if (value)
- *entry->value |= BIT(offset);
- else
- *entry->value &= ~BIT(offset);
-
- qcom_smp2p_kick(entry->smp2p);
-
- return 0;
-}
-
-static void smp2p_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
-{
- smp2p_gpio_direction_output(chip, offset, value);
-}
-
-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 qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p,
- struct smp2p_entry *entry,
- struct device_node *node)
-{
- struct smp2p_smem_item *out = smp2p->out;
- struct gpio_chip *chip;
- int ret;
-
- /* Allocate an entry from the smem item */
- memcpy_toio(out->entries[out->valid_entries].name, entry->name, SMP2P_MAX_ENTRY_NAME);
- out->valid_entries++;
-
- /* Make the logical entry reference the physical value */
- entry->value = &out->entries[out->valid_entries].value;
-
- chip = &entry->chip;
- chip->base = -1;
- chip->ngpio = 32;
- chip->label = entry->name;
- chip->dev = smp2p->dev;
- chip->owner = THIS_MODULE;
- chip->of_node = node;
-
- chip->set = smp2p_gpio_set;
- chip->direction_output = smp2p_gpio_direction_output;
-
- ret = gpiochip_add(chip);
- if (ret)
- dev_err(smp2p->dev, "failed register gpiochip\n");
-
- 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_io(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;
-
- ret = of_property_read_string(node, "qcom,entry-name", &entry->name);
- if (ret < 0)
- goto unwind_interfaces;
-
- if (of_property_read_bool(node, "qcom,inbound")) {
- ret = qcom_smp2p_inbound_entry(smp2p, entry, node);
- if (ret < 0)
- goto unwind_interfaces;
-
- list_add(&entry->node, &smp2p->inbound);
- } else if (of_property_read_bool(node, "qcom,outbound")) {
- ret = qcom_smp2p_outbound_entry(smp2p, entry, node);
- if (ret < 0)
- goto unwind_interfaces;
-
- list_add(&entry->node, &smp2p->outbound);
- } else {
- dev_err(&pdev->dev, "neither inbound nor outbound\n");
- ret = -EINVAL;
- goto unwind_interfaces;
- }
- }
-
- /* 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)
- gpiochip_remove(&entry->chip);
-
- 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)
- gpiochip_remove(&entry->chip);
-
- 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