![Bjorn Andersson](/assets/img/avatar_default.png)
Introduce the Qualcomm Shard Memory Point to Point driver. Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> Signed-off-by: Andy Gross <agross@codeaurora.org>
579 lines
14 KiB
C
579 lines
14 KiB
C
/*
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* Copyright (c) 2015, Sony Mobile Communications AB.
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* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/interrupt.h>
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#include <linux/list.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/irq.h>
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#include <linux/irqdomain.h>
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#include <linux/mfd/syscon.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/soc/qcom/smem.h>
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#include <linux/soc/qcom/smem_state.h>
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#include <linux/spinlock.h>
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/*
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* The Shared Memory Point to Point (SMP2P) protocol facilitates communication
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* of a single 32-bit value between two processors. Each value has a single
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* writer (the local side) and a single reader (the remote side). Values are
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* uniquely identified in the system by the directed edge (local processor ID
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* to remote processor ID) and a string identifier.
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*
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* Each processor is responsible for creating the outgoing SMEM items and each
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* item is writable by the local processor and readable by the remote
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* processor. By using two separate SMEM items that are single-reader and
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* single-writer, SMP2P does not require any remote locking mechanisms.
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*
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* The driver uses the Linux GPIO and interrupt framework to expose a virtual
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* GPIO for each outbound entry and a virtual interrupt controller for each
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* inbound entry.
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*/
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#define SMP2P_MAX_ENTRY 16
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#define SMP2P_MAX_ENTRY_NAME 16
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#define SMP2P_FEATURE_SSR_ACK 0x1
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#define SMP2P_MAGIC 0x504d5324
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/**
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* struct smp2p_smem_item - in memory communication structure
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* @magic: magic number
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* @version: version - must be 1
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* @features: features flag - currently unused
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* @local_pid: processor id of sending end
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* @remote_pid: processor id of receiving end
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* @total_entries: number of entries - always SMP2P_MAX_ENTRY
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* @valid_entries: number of allocated entries
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* @flags:
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* @entries: individual communication entries
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* @name: name of the entry
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* @value: content of the entry
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*/
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struct smp2p_smem_item {
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u32 magic;
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u8 version;
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unsigned features:24;
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u16 local_pid;
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u16 remote_pid;
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u16 total_entries;
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u16 valid_entries;
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u32 flags;
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struct {
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u8 name[SMP2P_MAX_ENTRY_NAME];
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u32 value;
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} entries[SMP2P_MAX_ENTRY];
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} __packed;
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/**
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* struct smp2p_entry - driver context matching one entry
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* @node: list entry to keep track of allocated entries
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* @smp2p: reference to the device driver context
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* @name: name of the entry, to match against smp2p_smem_item
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* @value: pointer to smp2p_smem_item entry value
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* @last_value: last handled value
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* @domain: irq_domain for inbound entries
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* @irq_enabled:bitmap to track enabled irq bits
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* @irq_rising: bitmap to mark irq bits for rising detection
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* @irq_falling:bitmap to mark irq bits for falling detection
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* @state: smem state handle
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* @lock: spinlock to protect read-modify-write of the value
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*/
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struct smp2p_entry {
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struct list_head node;
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struct qcom_smp2p *smp2p;
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const char *name;
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u32 *value;
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u32 last_value;
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struct irq_domain *domain;
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DECLARE_BITMAP(irq_enabled, 32);
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DECLARE_BITMAP(irq_rising, 32);
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DECLARE_BITMAP(irq_falling, 32);
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struct qcom_smem_state *state;
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spinlock_t lock;
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};
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#define SMP2P_INBOUND 0
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#define SMP2P_OUTBOUND 1
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/**
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* struct qcom_smp2p - device driver context
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* @dev: device driver handle
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* @in: pointer to the inbound smem item
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* @smem_items: ids of the two smem items
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* @valid_entries: already scanned inbound entries
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* @local_pid: processor id of the inbound edge
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* @remote_pid: processor id of the outbound edge
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* @ipc_regmap: regmap for the outbound ipc
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* @ipc_offset: offset within the regmap
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* @ipc_bit: bit in regmap@offset to kick to signal remote processor
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* @inbound: list of inbound entries
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* @outbound: list of outbound entries
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*/
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struct qcom_smp2p {
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struct device *dev;
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struct smp2p_smem_item *in;
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struct smp2p_smem_item *out;
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unsigned smem_items[SMP2P_OUTBOUND + 1];
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unsigned valid_entries;
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unsigned local_pid;
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unsigned remote_pid;
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struct regmap *ipc_regmap;
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int ipc_offset;
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int ipc_bit;
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struct list_head inbound;
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struct list_head outbound;
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};
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static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
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{
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/* Make sure any updated data is written before the kick */
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wmb();
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regmap_write(smp2p->ipc_regmap, smp2p->ipc_offset, BIT(smp2p->ipc_bit));
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}
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/**
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* qcom_smp2p_intr() - interrupt handler for incoming notifications
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* @irq: unused
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* @data: smp2p driver context
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*
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* Handle notifications from the remote side to handle newly allocated entries
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* or any changes to the state bits of existing entries.
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*/
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static irqreturn_t qcom_smp2p_intr(int irq, void *data)
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{
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struct smp2p_smem_item *in;
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struct smp2p_entry *entry;
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struct qcom_smp2p *smp2p = data;
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unsigned smem_id = smp2p->smem_items[SMP2P_INBOUND];
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unsigned pid = smp2p->remote_pid;
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size_t size;
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int irq_pin;
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u32 status;
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char buf[SMP2P_MAX_ENTRY_NAME];
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u32 val;
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int i;
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in = smp2p->in;
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/* Acquire smem item, if not already found */
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if (!in) {
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in = qcom_smem_get(pid, smem_id, &size);
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if (IS_ERR(in)) {
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dev_err(smp2p->dev,
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"Unable to acquire remote smp2p item\n");
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return IRQ_HANDLED;
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}
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smp2p->in = in;
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}
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/* Match newly created entries */
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for (i = smp2p->valid_entries; i < in->valid_entries; i++) {
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list_for_each_entry(entry, &smp2p->inbound, node) {
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memcpy_fromio(buf, in->entries[i].name, sizeof(buf));
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if (!strcmp(buf, entry->name)) {
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entry->value = &in->entries[i].value;
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break;
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}
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}
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}
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smp2p->valid_entries = i;
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/* Fire interrupts based on any value changes */
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list_for_each_entry(entry, &smp2p->inbound, node) {
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/* Ignore entries not yet allocated by the remote side */
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if (!entry->value)
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continue;
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val = readl(entry->value);
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status = val ^ entry->last_value;
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entry->last_value = val;
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/* No changes of this entry? */
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if (!status)
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continue;
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for_each_set_bit(i, entry->irq_enabled, 32) {
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if (!(status & BIT(i)))
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continue;
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if ((val & BIT(i) && test_bit(i, entry->irq_rising)) ||
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(!(val & BIT(i)) && test_bit(i, entry->irq_falling))) {
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irq_pin = irq_find_mapping(entry->domain, i);
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handle_nested_irq(irq_pin);
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}
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}
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}
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return IRQ_HANDLED;
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}
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static void smp2p_mask_irq(struct irq_data *irqd)
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{
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struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
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irq_hw_number_t irq = irqd_to_hwirq(irqd);
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clear_bit(irq, entry->irq_enabled);
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}
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static void smp2p_unmask_irq(struct irq_data *irqd)
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{
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struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
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irq_hw_number_t irq = irqd_to_hwirq(irqd);
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set_bit(irq, entry->irq_enabled);
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}
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static int smp2p_set_irq_type(struct irq_data *irqd, unsigned int type)
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{
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struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
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irq_hw_number_t irq = irqd_to_hwirq(irqd);
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if (!(type & IRQ_TYPE_EDGE_BOTH))
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return -EINVAL;
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if (type & IRQ_TYPE_EDGE_RISING)
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set_bit(irq, entry->irq_rising);
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else
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clear_bit(irq, entry->irq_rising);
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if (type & IRQ_TYPE_EDGE_FALLING)
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set_bit(irq, entry->irq_falling);
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else
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clear_bit(irq, entry->irq_falling);
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return 0;
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}
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static struct irq_chip smp2p_irq_chip = {
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.name = "smp2p",
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.irq_mask = smp2p_mask_irq,
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.irq_unmask = smp2p_unmask_irq,
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.irq_set_type = smp2p_set_irq_type,
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};
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static int smp2p_irq_map(struct irq_domain *d,
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unsigned int irq,
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irq_hw_number_t hw)
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{
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struct smp2p_entry *entry = d->host_data;
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irq_set_chip_and_handler(irq, &smp2p_irq_chip, handle_level_irq);
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irq_set_chip_data(irq, entry);
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irq_set_nested_thread(irq, 1);
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irq_set_noprobe(irq);
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return 0;
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}
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static const struct irq_domain_ops smp2p_irq_ops = {
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.map = smp2p_irq_map,
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.xlate = irq_domain_xlate_twocell,
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};
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static int qcom_smp2p_inbound_entry(struct qcom_smp2p *smp2p,
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struct smp2p_entry *entry,
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struct device_node *node)
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{
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entry->domain = irq_domain_add_linear(node, 32, &smp2p_irq_ops, entry);
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if (!entry->domain) {
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dev_err(smp2p->dev, "failed to add irq_domain\n");
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return -ENOMEM;
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}
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return 0;
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}
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static int smp2p_update_bits(void *data, u32 mask, u32 value)
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{
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struct smp2p_entry *entry = data;
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u32 orig;
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u32 val;
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spin_lock(&entry->lock);
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val = orig = readl(entry->value);
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val &= ~mask;
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val |= value;
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writel(val, entry->value);
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spin_unlock(&entry->lock);
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if (val != orig)
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qcom_smp2p_kick(entry->smp2p);
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return 0;
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}
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static const struct qcom_smem_state_ops smp2p_state_ops = {
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.update_bits = smp2p_update_bits,
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};
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static int qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p,
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struct smp2p_entry *entry,
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struct device_node *node)
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{
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struct smp2p_smem_item *out = smp2p->out;
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char buf[SMP2P_MAX_ENTRY_NAME] = {};
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/* Allocate an entry from the smem item */
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strlcpy(buf, entry->name, SMP2P_MAX_ENTRY_NAME);
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memcpy_toio(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME);
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out->valid_entries++;
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/* Make the logical entry reference the physical value */
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entry->value = &out->entries[out->valid_entries].value;
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entry->state = qcom_smem_state_register(node, &smp2p_state_ops, entry);
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if (IS_ERR(entry->state)) {
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dev_err(smp2p->dev, "failed to register qcom_smem_state\n");
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return PTR_ERR(entry->state);
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}
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return 0;
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}
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static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
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{
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struct smp2p_smem_item *out;
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unsigned smem_id = smp2p->smem_items[SMP2P_OUTBOUND];
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unsigned pid = smp2p->remote_pid;
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int ret;
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ret = qcom_smem_alloc(pid, smem_id, sizeof(*out));
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if (ret < 0 && ret != -EEXIST) {
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if (ret != -EPROBE_DEFER)
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dev_err(smp2p->dev,
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"unable to allocate local smp2p item\n");
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return ret;
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}
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out = qcom_smem_get(pid, smem_id, NULL);
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if (IS_ERR(out)) {
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dev_err(smp2p->dev, "Unable to acquire local smp2p item\n");
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return PTR_ERR(out);
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}
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memset(out, 0, sizeof(*out));
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out->magic = SMP2P_MAGIC;
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out->local_pid = smp2p->local_pid;
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out->remote_pid = smp2p->remote_pid;
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out->total_entries = SMP2P_MAX_ENTRY;
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out->valid_entries = 0;
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/*
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* Make sure the rest of the header is written before we validate the
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* item by writing a valid version number.
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*/
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wmb();
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out->version = 1;
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qcom_smp2p_kick(smp2p);
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smp2p->out = out;
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return 0;
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}
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static int smp2p_parse_ipc(struct qcom_smp2p *smp2p)
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{
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struct device_node *syscon;
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struct device *dev = smp2p->dev;
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const char *key;
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int ret;
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syscon = of_parse_phandle(dev->of_node, "qcom,ipc", 0);
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if (!syscon) {
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dev_err(dev, "no qcom,ipc node\n");
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return -ENODEV;
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}
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smp2p->ipc_regmap = syscon_node_to_regmap(syscon);
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if (IS_ERR(smp2p->ipc_regmap))
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return PTR_ERR(smp2p->ipc_regmap);
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key = "qcom,ipc";
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ret = of_property_read_u32_index(dev->of_node, key, 1, &smp2p->ipc_offset);
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if (ret < 0) {
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dev_err(dev, "no offset in %s\n", key);
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return -EINVAL;
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}
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ret = of_property_read_u32_index(dev->of_node, key, 2, &smp2p->ipc_bit);
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if (ret < 0) {
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dev_err(dev, "no bit in %s\n", key);
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return -EINVAL;
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}
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return 0;
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}
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static int qcom_smp2p_probe(struct platform_device *pdev)
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{
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struct smp2p_entry *entry;
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struct device_node *node;
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struct qcom_smp2p *smp2p;
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const char *key;
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int irq;
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int ret;
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smp2p = devm_kzalloc(&pdev->dev, sizeof(*smp2p), GFP_KERNEL);
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if (!smp2p)
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return -ENOMEM;
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smp2p->dev = &pdev->dev;
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INIT_LIST_HEAD(&smp2p->inbound);
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INIT_LIST_HEAD(&smp2p->outbound);
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platform_set_drvdata(pdev, smp2p);
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ret = smp2p_parse_ipc(smp2p);
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if (ret)
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return ret;
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key = "qcom,smem";
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ret = of_property_read_u32_array(pdev->dev.of_node, key,
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smp2p->smem_items, 2);
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if (ret)
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return ret;
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key = "qcom,local-pid";
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ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->local_pid);
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if (ret < 0) {
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dev_err(&pdev->dev, "failed to read %s\n", key);
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return -EINVAL;
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}
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key = "qcom,remote-pid";
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ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->remote_pid);
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if (ret < 0) {
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dev_err(&pdev->dev, "failed to read %s\n", key);
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return -EINVAL;
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}
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irq = platform_get_irq(pdev, 0);
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if (irq < 0) {
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dev_err(&pdev->dev, "unable to acquire smp2p interrupt\n");
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return irq;
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}
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ret = qcom_smp2p_alloc_outbound_item(smp2p);
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if (ret < 0)
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return ret;
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for_each_available_child_of_node(pdev->dev.of_node, node) {
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entry = devm_kzalloc(&pdev->dev, sizeof(*entry), GFP_KERNEL);
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if (!entry) {
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ret = -ENOMEM;
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goto unwind_interfaces;
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}
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entry->smp2p = smp2p;
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spin_lock_init(&entry->lock);
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|
|
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");
|