diff options
Diffstat (limited to 'drivers/soc/qcom/smsm.c')
| -rw-r--r-- | drivers/soc/qcom/smsm.c | 625 |
1 files changed, 625 insertions, 0 deletions
diff --git a/drivers/soc/qcom/smsm.c b/drivers/soc/qcom/smsm.c new file mode 100644 index 000000000000..6b777af1bc19 --- /dev/null +++ b/drivers/soc/qcom/smsm.c @@ -0,0 +1,625 @@ +/* + * Copyright (c) 2015, Sony Mobile Communications Inc. + * 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/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/regmap.h> +#include <linux/soc/qcom/smem.h> +#include <linux/soc/qcom/smem_state.h> + +/* + * This driver implements the Qualcomm Shared Memory State Machine, a mechanism + * for communicating single bit state information to remote processors. + * + * The implementation is based on two sections of shared memory; the first + * holding the state bits and the second holding a matrix of subscription bits. + * + * The state bits are structured in entries of 32 bits, each belonging to one + * system in the SoC. The entry belonging to the local system is considered + * read-write, while the rest should be considered read-only. + * + * The subscription matrix consists of N bitmaps per entry, denoting interest + * in updates of the entry for each of the N hosts. Upon updating a state bit + * each host's subscription bitmap should be queried and the remote system + * should be interrupted if they request so. + * + * The subscription matrix is laid out in entry-major order: + * entry0: [host0 ... hostN] + * . + * . + * entryM: [host0 ... hostN] + * + * A third, optional, shared memory region might contain information regarding + * the number of entries in the state bitmap as well as number of columns in + * the subscription matrix. + */ + +/* + * Shared memory identifiers, used to acquire handles to respective memory + * region. + */ +#define SMEM_SMSM_SHARED_STATE 85 +#define SMEM_SMSM_CPU_INTR_MASK 333 +#define SMEM_SMSM_SIZE_INFO 419 + +/* + * Default sizes, in case SMEM_SMSM_SIZE_INFO is not found. + */ +#define SMSM_DEFAULT_NUM_ENTRIES 8 +#define SMSM_DEFAULT_NUM_HOSTS 3 + +struct smsm_entry; +struct smsm_host; + +/** + * struct qcom_smsm - smsm driver context + * @dev: smsm device pointer + * @local_host: column in the subscription matrix representing this system + * @num_hosts: number of columns in the subscription matrix + * @num_entries: number of entries in the state map and rows in the subscription + * matrix + * @local_state: pointer to the local processor's state bits + * @subscription: pointer to local processor's row in subscription matrix + * @state: smem state handle + * @lock: spinlock for read-modify-write of the outgoing state + * @entries: context for each of the entries + * @hosts: context for each of the hosts + */ +struct qcom_smsm { + struct device *dev; + + u32 local_host; + + u32 num_hosts; + u32 num_entries; + + u32 *local_state; + u32 *subscription; + struct qcom_smem_state *state; + + spinlock_t lock; + + struct smsm_entry *entries; + struct smsm_host *hosts; +}; + +/** + * struct smsm_entry - per remote processor entry context + * @smsm: back-reference to driver context + * @domain: IRQ domain for this entry, if representing a remote system + * @irq_enabled: bitmap of which state bits IRQs are enabled + * @irq_rising: bitmap tracking if rising bits should be propagated + * @irq_falling: bitmap tracking if falling bits should be propagated + * @last_value: snapshot of state bits last time the interrupts where propagated + * @remote_state: pointer to this entry's state bits + * @subscription: pointer to a row in the subscription matrix representing this + * entry + */ +struct smsm_entry { + struct qcom_smsm *smsm; + + struct irq_domain *domain; + DECLARE_BITMAP(irq_enabled, 32); + DECLARE_BITMAP(irq_rising, 32); + DECLARE_BITMAP(irq_falling, 32); + u32 last_value; + + u32 *remote_state; + u32 *subscription; +}; + +/** + * struct smsm_host - representation of a remote host + * @ipc_regmap: regmap for outgoing interrupt + * @ipc_offset: offset in @ipc_regmap for outgoing interrupt + * @ipc_bit: bit in @ipc_regmap + @ipc_offset for outgoing interrupt + */ +struct smsm_host { + struct regmap *ipc_regmap; + int ipc_offset; + int ipc_bit; +}; + +/** + * smsm_update_bits() - change bit in outgoing entry and inform subscribers + * @data: smsm context pointer + * @offset: bit in the entry + * @value: new value + * + * Used to set and clear the bits in the outgoing/local entry and inform + * subscribers about the change. + */ +static int smsm_update_bits(void *data, u32 mask, u32 value) +{ + struct qcom_smsm *smsm = data; + struct smsm_host *hostp; + unsigned long flags; + u32 changes; + u32 host; + u32 orig; + u32 val; + + spin_lock_irqsave(&smsm->lock, flags); + + /* Update the entry */ + val = orig = readl(smsm->local_state); + val &= ~mask; + val |= value; + + /* Don't signal if we didn't change the value */ + changes = val ^ orig; + if (!changes) { + spin_unlock_irqrestore(&smsm->lock, flags); + goto done; + } + + /* Write out the new value */ + writel(val, smsm->local_state); + spin_unlock_irqrestore(&smsm->lock, flags); + + /* Make sure the value update is ordered before any kicks */ + wmb(); + + /* Iterate over all hosts to check whom wants a kick */ + for (host = 0; host < smsm->num_hosts; host++) { + hostp = &smsm->hosts[host]; + + val = readl(smsm->subscription + host); + if (val & changes && hostp->ipc_regmap) { + regmap_write(hostp->ipc_regmap, + hostp->ipc_offset, + BIT(hostp->ipc_bit)); + } + } + +done: + return 0; +} + +static const struct qcom_smem_state_ops smsm_state_ops = { + .update_bits = smsm_update_bits, +}; + +/** + * smsm_intr() - cascading IRQ handler for SMSM + * @irq: unused + * @data: entry related to this IRQ + * + * This function cascades an incoming interrupt from a remote system, based on + * the state bits and configuration. + */ +static irqreturn_t smsm_intr(int irq, void *data) +{ + struct smsm_entry *entry = data; + unsigned i; + int irq_pin; + u32 changed; + u32 val; + + val = readl(entry->remote_state); + changed = val ^ entry->last_value; + entry->last_value = val; + + for_each_set_bit(i, entry->irq_enabled, 32) { + if (!(changed & 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; +} + +/** + * smsm_mask_irq() - un-subscribe from cascades of IRQs of a certain staus bit + * @irqd: IRQ handle to be masked + * + * This un-subscribes the local CPU from interrupts upon changes to the defines + * status bit. The bit is also cleared from cascading. + */ +static void smsm_mask_irq(struct irq_data *irqd) +{ + struct smsm_entry *entry = irq_data_get_irq_chip_data(irqd); + irq_hw_number_t irq = irqd_to_hwirq(irqd); + struct qcom_smsm *smsm = entry->smsm; + u32 val; + + if (entry->subscription) { + val = readl(entry->subscription + smsm->local_host); + val &= ~BIT(irq); + writel(val, entry->subscription + smsm->local_host); + } + + clear_bit(irq, entry->irq_enabled); +} + +/** + * smsm_unmask_irq() - subscribe to cascades of IRQs of a certain status bit + * @irqd: IRQ handle to be unmasked + * + + * This subscribes the local CPU to interrupts upon changes to the defined + * status bit. The bit is also marked for cascading. + + */ +static void smsm_unmask_irq(struct irq_data *irqd) +{ + struct smsm_entry *entry = irq_data_get_irq_chip_data(irqd); + irq_hw_number_t irq = irqd_to_hwirq(irqd); + struct qcom_smsm *smsm = entry->smsm; + u32 val; + + set_bit(irq, entry->irq_enabled); + + if (entry->subscription) { + val = readl(entry->subscription + smsm->local_host); + val |= BIT(irq); + writel(val, entry->subscription + smsm->local_host); + } +} + +/** + * smsm_set_irq_type() - updates the requested IRQ type for the cascading + * @irqd: consumer interrupt handle + * @type: requested flags + */ +static int smsm_set_irq_type(struct irq_data *irqd, unsigned int type) +{ + struct smsm_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 smsm_irq_chip = { + .name = "smsm", + .irq_mask = smsm_mask_irq, + .irq_unmask = smsm_unmask_irq, + .irq_set_type = smsm_set_irq_type, +}; + +/** + * smsm_irq_map() - sets up a mapping for a cascaded IRQ + * @d: IRQ domain representing an entry + * @irq: IRQ to set up + * @hw: unused + */ +static int smsm_irq_map(struct irq_domain *d, + unsigned int irq, + irq_hw_number_t hw) +{ + struct smsm_entry *entry = d->host_data; + + irq_set_chip_and_handler(irq, &smsm_irq_chip, handle_level_irq); + irq_set_chip_data(irq, entry); + irq_set_nested_thread(irq, 1); + + return 0; +} + +static const struct irq_domain_ops smsm_irq_ops = { + .map = smsm_irq_map, + .xlate = irq_domain_xlate_twocell, +}; + +/** + * smsm_parse_ipc() - parses a qcom,ipc-%d device tree property + * @smsm: smsm driver context + * @host_id: index of the remote host to be resolved + * + * Parses device tree to acquire the information needed for sending the + * outgoing interrupts to a remote host - identified by @host_id. + */ +static int smsm_parse_ipc(struct qcom_smsm *smsm, unsigned host_id) +{ + struct device_node *syscon; + struct device_node *node = smsm->dev->of_node; + struct smsm_host *host = &smsm->hosts[host_id]; + char key[16]; + int ret; + + snprintf(key, sizeof(key), "qcom,ipc-%d", host_id); + syscon = of_parse_phandle(node, key, 0); + if (!syscon) + return 0; + + host->ipc_regmap = syscon_node_to_regmap(syscon); + if (IS_ERR(host->ipc_regmap)) + return PTR_ERR(host->ipc_regmap); + + ret = of_property_read_u32_index(node, key, 1, &host->ipc_offset); + if (ret < 0) { + dev_err(smsm->dev, "no offset in %s\n", key); + return -EINVAL; + } + + ret = of_property_read_u32_index(node, key, 2, &host->ipc_bit); + if (ret < 0) { + dev_err(smsm->dev, "no bit in %s\n", key); + return -EINVAL; + } + + return 0; +} + +/** + * smsm_inbound_entry() - parse DT and set up an entry representing a remote system + * @smsm: smsm driver context + * @entry: entry context to be set up + * @node: dt node containing the entry's properties + */ +static int smsm_inbound_entry(struct qcom_smsm *smsm, + struct smsm_entry *entry, + struct device_node *node) +{ + int ret; + int irq; + + irq = irq_of_parse_and_map(node, 0); + if (!irq) { + dev_err(smsm->dev, "failed to parse smsm interrupt\n"); + return -EINVAL; + } + + ret = devm_request_threaded_irq(smsm->dev, irq, + NULL, smsm_intr, + IRQF_ONESHOT, + "smsm", (void *)entry); + if (ret) { + dev_err(smsm->dev, "failed to request interrupt\n"); + return ret; + } + + entry->domain = irq_domain_add_linear(node, 32, &smsm_irq_ops, entry); + if (!entry->domain) { + dev_err(smsm->dev, "failed to add irq_domain\n"); + return -ENOMEM; + } + + return 0; +} + +/** + * smsm_get_size_info() - parse the optional memory segment for sizes + * @smsm: smsm driver context + * + * Attempt to acquire the number of hosts and entries from the optional shared + * memory location. Not being able to find this segment should indicate that + * we're on a older system where these values was hard coded to + * SMSM_DEFAULT_NUM_ENTRIES and SMSM_DEFAULT_NUM_HOSTS. + * + * Returns 0 on success, negative errno on failure. + */ +static int smsm_get_size_info(struct qcom_smsm *smsm) +{ + size_t size; + struct { + u32 num_hosts; + u32 num_entries; + u32 reserved0; + u32 reserved1; + } *info; + + info = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_SMSM_SIZE_INFO, &size); + if (PTR_ERR(info) == -ENOENT || size != sizeof(*info)) { + dev_warn(smsm->dev, "no smsm size info, using defaults\n"); + smsm->num_entries = SMSM_DEFAULT_NUM_ENTRIES; + smsm->num_hosts = SMSM_DEFAULT_NUM_HOSTS; + return 0; + } else if (IS_ERR(info)) { + dev_err(smsm->dev, "unable to retrieve smsm size info\n"); + return PTR_ERR(info); + } + + smsm->num_entries = info->num_entries; + smsm->num_hosts = info->num_hosts; + + dev_dbg(smsm->dev, + "found custom size of smsm: %d entries %d hosts\n", + smsm->num_entries, smsm->num_hosts); + + return 0; +} + +static int qcom_smsm_probe(struct platform_device *pdev) +{ + struct device_node *local_node; + struct device_node *node; + struct smsm_entry *entry; + struct qcom_smsm *smsm; + u32 *intr_mask; + size_t size; + u32 *states; + u32 id; + int ret; + + smsm = devm_kzalloc(&pdev->dev, sizeof(*smsm), GFP_KERNEL); + if (!smsm) + return -ENOMEM; + smsm->dev = &pdev->dev; + spin_lock_init(&smsm->lock); + + ret = smsm_get_size_info(smsm); + if (ret) + return ret; + + smsm->entries = devm_kcalloc(&pdev->dev, + smsm->num_entries, + sizeof(struct smsm_entry), + GFP_KERNEL); + if (!smsm->entries) + return -ENOMEM; + + smsm->hosts = devm_kcalloc(&pdev->dev, + smsm->num_hosts, + sizeof(struct smsm_host), + GFP_KERNEL); + if (!smsm->hosts) + return -ENOMEM; + + local_node = of_find_node_with_property(pdev->dev.of_node, "#qcom,state-cells"); + if (!local_node) { + dev_err(&pdev->dev, "no state entry\n"); + return -EINVAL; + } + + of_property_read_u32(pdev->dev.of_node, + "qcom,local-host", + &smsm->local_host); + + /* Parse the host properties */ + for (id = 0; id < smsm->num_hosts; id++) { + ret = smsm_parse_ipc(smsm, id); + if (ret < 0) + return ret; + } + + /* Acquire the main SMSM state vector */ + ret = qcom_smem_alloc(QCOM_SMEM_HOST_ANY, SMEM_SMSM_SHARED_STATE, + smsm->num_entries * sizeof(u32)); + if (ret < 0 && ret != -EEXIST) { + dev_err(&pdev->dev, "unable to allocate shared state entry\n"); + return ret; + } + + states = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_SMSM_SHARED_STATE, NULL); + if (IS_ERR(states)) { + dev_err(&pdev->dev, "Unable to acquire shared state entry\n"); + return PTR_ERR(states); + } + + /* Acquire the list of interrupt mask vectors */ + size = smsm->num_entries * smsm->num_hosts * sizeof(u32); + ret = qcom_smem_alloc(QCOM_SMEM_HOST_ANY, SMEM_SMSM_CPU_INTR_MASK, size); + if (ret < 0 && ret != -EEXIST) { + dev_err(&pdev->dev, "unable to allocate smsm interrupt mask\n"); + return ret; + } + + intr_mask = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_SMSM_CPU_INTR_MASK, NULL); + if (IS_ERR(intr_mask)) { + dev_err(&pdev->dev, "unable to acquire shared memory interrupt mask\n"); + return PTR_ERR(intr_mask); + } + + /* Setup the reference to the local state bits */ + smsm->local_state = states + smsm->local_host; + smsm->subscription = intr_mask + smsm->local_host * smsm->num_hosts; + + /* Register the outgoing state */ + smsm->state = qcom_smem_state_register(local_node, &smsm_state_ops, smsm); + if (IS_ERR(smsm->state)) { + dev_err(smsm->dev, "failed to register qcom_smem_state\n"); + return PTR_ERR(smsm->state); + } + + /* Register handlers for remote processor entries of interest. */ + for_each_available_child_of_node(pdev->dev.of_node, node) { + if (!of_property_read_bool(node, "interrupt-controller")) + continue; + + ret = of_property_read_u32(node, "reg", &id); + if (ret || id >= smsm->num_entries) { + dev_err(&pdev->dev, "invalid reg of entry\n"); + if (!ret) + ret = -EINVAL; + goto unwind_interfaces; + } + entry = &smsm->entries[id]; + + entry->smsm = smsm; + entry->remote_state = states + id; + + /* Setup subscription pointers and unsubscribe to any kicks */ + entry->subscription = intr_mask + id * smsm->num_hosts; + writel(0, entry->subscription + smsm->local_host); + + ret = smsm_inbound_entry(smsm, entry, node); + if (ret < 0) + goto unwind_interfaces; + } + + platform_set_drvdata(pdev, smsm); + + return 0; + +unwind_interfaces: + for (id = 0; id < smsm->num_entries; id++) + if (smsm->entries[id].domain) + irq_domain_remove(smsm->entries[id].domain); + + qcom_smem_state_unregister(smsm->state); + + return ret; +} + +static int qcom_smsm_remove(struct platform_device *pdev) +{ + struct qcom_smsm *smsm = platform_get_drvdata(pdev); + unsigned id; + + for (id = 0; id < smsm->num_entries; id++) + if (smsm->entries[id].domain) + irq_domain_remove(smsm->entries[id].domain); + + qcom_smem_state_unregister(smsm->state); + + return 0; +} + +static const struct of_device_id qcom_smsm_of_match[] = { + { .compatible = "qcom,smsm" }, + {} +}; +MODULE_DEVICE_TABLE(of, qcom_smsm_of_match); + +static struct platform_driver qcom_smsm_driver = { + .probe = qcom_smsm_probe, + .remove = qcom_smsm_remove, + .driver = { + .name = "qcom-smsm", + .of_match_table = qcom_smsm_of_match, + }, +}; +module_platform_driver(qcom_smsm_driver); + +MODULE_DESCRIPTION("Qualcomm Shared Memory State Machine driver"); +MODULE_LICENSE("GPL v2"); |