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598 lines
15 KiB
598 lines
15 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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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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|
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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/mailbox_client.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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/* |
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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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* @out: pointer to the outbound 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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* @mbox_client: mailbox client handle |
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* @mbox_chan: apcs ipc mailbox channel handle |
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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 mbox_client mbox_client; |
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struct mbox_chan *mbox_chan; |
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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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if (smp2p->mbox_chan) { |
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mbox_send_message(smp2p->mbox_chan, NULL); |
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mbox_client_txdone(smp2p->mbox_chan, 0); |
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} else { |
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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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/** |
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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(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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unsigned long flags; |
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u32 orig; |
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u32 val; |
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spin_lock_irqsave(&entry->lock, flags); |
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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_irqrestore(&entry->lock, flags); |
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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(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME); |
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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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out->valid_entries++; |
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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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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) |
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goto report_read_failure; |
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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) |
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goto report_read_failure; |
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irq = platform_get_irq(pdev, 0); |
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if (irq < 0) |
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return irq; |
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smp2p->mbox_client.dev = &pdev->dev; |
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smp2p->mbox_client.knows_txdone = true; |
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smp2p->mbox_chan = mbox_request_channel(&smp2p->mbox_client, 0); |
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if (IS_ERR(smp2p->mbox_chan)) { |
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if (PTR_ERR(smp2p->mbox_chan) != -ENODEV) |
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return PTR_ERR(smp2p->mbox_chan); |
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smp2p->mbox_chan = NULL; |
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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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} |
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ret = qcom_smp2p_alloc_outbound_item(smp2p); |
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if (ret < 0) |
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goto release_mbox; |
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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); |
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if (ret < 0) |
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goto unwind_interfaces; |
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if (of_property_read_bool(node, "interrupt-controller")) { |
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ret = qcom_smp2p_inbound_entry(smp2p, entry, node); |
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if (ret < 0) |
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goto unwind_interfaces; |
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list_add(&entry->node, &smp2p->inbound); |
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} else { |
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ret = qcom_smp2p_outbound_entry(smp2p, entry, node); |
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if (ret < 0) |
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goto unwind_interfaces; |
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list_add(&entry->node, &smp2p->outbound); |
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} |
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} |
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/* Kick the outgoing edge after allocating entries */ |
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qcom_smp2p_kick(smp2p); |
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ret = devm_request_threaded_irq(&pdev->dev, irq, |
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NULL, qcom_smp2p_intr, |
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IRQF_ONESHOT, |
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"smp2p", (void *)smp2p); |
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if (ret) { |
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dev_err(&pdev->dev, "failed to request interrupt\n"); |
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goto unwind_interfaces; |
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} |
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return 0; |
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unwind_interfaces: |
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list_for_each_entry(entry, &smp2p->inbound, node) |
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irq_domain_remove(entry->domain); |
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list_for_each_entry(entry, &smp2p->outbound, node) |
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qcom_smem_state_unregister(entry->state); |
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smp2p->out->valid_entries = 0; |
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|
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release_mbox: |
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mbox_free_channel(smp2p->mbox_chan); |
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return ret; |
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report_read_failure: |
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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");
|
|
|