diff options
Diffstat (limited to 'drivers/soc/qcom/smp2p.c')
| -rw-r--r-- | drivers/soc/qcom/smp2p.c | 578 |
1 files changed, 578 insertions, 0 deletions
diff --git a/drivers/soc/qcom/smp2p.c b/drivers/soc/qcom/smp2p.c new file mode 100644 index 000000000000..f1eed7f9dd67 --- /dev/null +++ b/drivers/soc/qcom/smp2p.c @@ -0,0 +1,578 @@ +/* + * 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"); |