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- // SPDX-License-Identifier: GPL-2.0
- /* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
- * Copyright (C) 2018-2024 Linaro Ltd.
- */
- /* DOC: IPA Interrupts
- *
- * The IPA has an interrupt line distinct from the interrupt used by the GSI
- * code. Whereas GSI interrupts are generally related to channel events (like
- * transfer completions), IPA interrupts are related to other events related
- * to the IPA. Some of the IPA interrupts come from a microcontroller
- * embedded in the IPA. Each IPA interrupt type can be both masked and
- * acknowledged independent of the others.
- *
- * Two of the IPA interrupts are initiated by the microcontroller. A third
- * can be generated to signal the need for a wakeup/resume when an IPA
- * endpoint has been suspended. There are other IPA events, but at this
- * time only these three are supported.
- */
- #include <linux/interrupt.h>
- #include <linux/platform_device.h>
- #include <linux/pm_runtime.h>
- #include <linux/pm_wakeirq.h>
- #include <linux/types.h>
- #include "ipa.h"
- #include "ipa_endpoint.h"
- #include "ipa_interrupt.h"
- #include "ipa_power.h"
- #include "ipa_reg.h"
- #include "ipa_uc.h"
- /**
- * struct ipa_interrupt - IPA interrupt information
- * @ipa: IPA pointer
- * @irq: Linux IRQ number used for IPA interrupts
- * @enabled: Mask indicating which interrupts are enabled
- * @suspend_enabled: Bitmap of endpoints with the SUSPEND interrupt enabled
- */
- struct ipa_interrupt {
- struct ipa *ipa;
- u32 irq;
- u32 enabled;
- unsigned long *suspend_enabled;
- };
- /* Clear the suspend interrupt for all endpoints that signaled it */
- static void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt)
- {
- struct ipa *ipa = interrupt->ipa;
- u32 unit_count;
- u32 unit;
- unit_count = DIV_ROUND_UP(ipa->endpoint_count, 32);
- for (unit = 0; unit < unit_count; unit++) {
- const struct reg *reg;
- u32 val;
- reg = ipa_reg(ipa, IRQ_SUSPEND_INFO);
- val = ioread32(ipa->reg_virt + reg_n_offset(reg, unit));
- /* SUSPEND interrupt status isn't cleared on IPA version 3.0 */
- if (!val || ipa->version == IPA_VERSION_3_0)
- continue;
- reg = ipa_reg(ipa, IRQ_SUSPEND_CLR);
- iowrite32(val, ipa->reg_virt + reg_n_offset(reg, unit));
- }
- }
- /* Process a particular interrupt type that has been received */
- static void ipa_interrupt_process(struct ipa_interrupt *interrupt, u32 irq_id)
- {
- struct ipa *ipa = interrupt->ipa;
- const struct reg *reg;
- u32 mask = BIT(irq_id);
- u32 offset;
- reg = ipa_reg(ipa, IPA_IRQ_CLR);
- offset = reg_offset(reg);
- switch (irq_id) {
- case IPA_IRQ_UC_0:
- case IPA_IRQ_UC_1:
- /* For microcontroller interrupts, clear the interrupt right
- * away, "to avoid clearing unhandled interrupts."
- */
- iowrite32(mask, ipa->reg_virt + offset);
- ipa_uc_interrupt_handler(ipa, irq_id);
- break;
- case IPA_IRQ_TX_SUSPEND:
- /* Clearing the SUSPEND_TX interrupt also clears the
- * register that tells us which suspended endpoint(s)
- * caused the interrupt, so defer clearing until after
- * the handler has been called.
- */
- ipa_interrupt_suspend_clear_all(interrupt);
- fallthrough;
- default: /* Silently ignore (and clear) any other condition */
- iowrite32(mask, ipa->reg_virt + offset);
- break;
- }
- }
- /* IPA IRQ handler is threaded */
- static irqreturn_t ipa_isr_thread(int irq, void *dev_id)
- {
- struct ipa_interrupt *interrupt = dev_id;
- struct ipa *ipa = interrupt->ipa;
- u32 enabled = interrupt->enabled;
- struct device *dev = ipa->dev;
- const struct reg *reg;
- u32 pending;
- u32 offset;
- u32 mask;
- int ret;
- ret = pm_runtime_get_sync(dev);
- if (WARN_ON(ret < 0))
- goto out_power_put;
- /* The status register indicates which conditions are present,
- * including conditions whose interrupt is not enabled. Handle
- * only the enabled ones.
- */
- reg = ipa_reg(ipa, IPA_IRQ_STTS);
- offset = reg_offset(reg);
- pending = ioread32(ipa->reg_virt + offset);
- while ((mask = pending & enabled)) {
- do {
- u32 irq_id = __ffs(mask);
- mask ^= BIT(irq_id);
- ipa_interrupt_process(interrupt, irq_id);
- } while (mask);
- pending = ioread32(ipa->reg_virt + offset);
- }
- /* If any disabled interrupts are pending, clear them */
- if (pending) {
- dev_dbg(dev, "clearing disabled IPA interrupts 0x%08x\n",
- pending);
- reg = ipa_reg(ipa, IPA_IRQ_CLR);
- iowrite32(pending, ipa->reg_virt + reg_offset(reg));
- }
- out_power_put:
- pm_runtime_mark_last_busy(dev);
- (void)pm_runtime_put_autosuspend(dev);
- return IRQ_HANDLED;
- }
- static void ipa_interrupt_enabled_update(struct ipa *ipa)
- {
- const struct reg *reg = ipa_reg(ipa, IPA_IRQ_EN);
- iowrite32(ipa->interrupt->enabled, ipa->reg_virt + reg_offset(reg));
- }
- /* Enable an IPA interrupt type */
- void ipa_interrupt_enable(struct ipa *ipa, enum ipa_irq_id ipa_irq)
- {
- /* Update the IPA interrupt mask to enable it */
- ipa->interrupt->enabled |= BIT(ipa_irq);
- ipa_interrupt_enabled_update(ipa);
- }
- /* Disable an IPA interrupt type */
- void ipa_interrupt_disable(struct ipa *ipa, enum ipa_irq_id ipa_irq)
- {
- /* Update the IPA interrupt mask to disable it */
- ipa->interrupt->enabled &= ~BIT(ipa_irq);
- ipa_interrupt_enabled_update(ipa);
- }
- void ipa_interrupt_irq_disable(struct ipa *ipa)
- {
- disable_irq(ipa->interrupt->irq);
- }
- void ipa_interrupt_irq_enable(struct ipa *ipa)
- {
- enable_irq(ipa->interrupt->irq);
- }
- /* Common function used to enable/disable TX_SUSPEND for an endpoint */
- static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt,
- u32 endpoint_id, bool enable)
- {
- struct ipa *ipa = interrupt->ipa;
- u32 mask = BIT(endpoint_id % 32);
- u32 unit = endpoint_id / 32;
- const struct reg *reg;
- unsigned long weight;
- u32 offset;
- u32 val;
- WARN_ON(!test_bit(endpoint_id, ipa->available));
- /* IPA version 3.0 does not support TX_SUSPEND interrupt control */
- if (ipa->version == IPA_VERSION_3_0)
- return;
- weight = bitmap_weight(interrupt->suspend_enabled, ipa->endpoint_count);
- if (weight == 1 && !enable)
- ipa_interrupt_disable(ipa, IPA_IRQ_TX_SUSPEND);
- reg = ipa_reg(ipa, IRQ_SUSPEND_EN);
- offset = reg_n_offset(reg, unit);
- val = ioread32(ipa->reg_virt + offset);
- if (enable)
- val |= mask;
- else
- val &= ~mask;
- __change_bit(endpoint_id, interrupt->suspend_enabled);
- iowrite32(val, ipa->reg_virt + offset);
- if (!weight && enable)
- ipa_interrupt_enable(ipa, IPA_IRQ_TX_SUSPEND);
- }
- /* Enable TX_SUSPEND for an endpoint */
- void
- ipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt, u32 endpoint_id)
- {
- ipa_interrupt_suspend_control(interrupt, endpoint_id, true);
- }
- /* Disable TX_SUSPEND for an endpoint */
- void
- ipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt, u32 endpoint_id)
- {
- ipa_interrupt_suspend_control(interrupt, endpoint_id, false);
- }
- /* Simulate arrival of an IPA TX_SUSPEND interrupt */
- void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt)
- {
- ipa_interrupt_process(interrupt, IPA_IRQ_TX_SUSPEND);
- }
- /* Configure the IPA interrupt framework */
- int ipa_interrupt_config(struct ipa *ipa)
- {
- struct ipa_interrupt *interrupt = ipa->interrupt;
- unsigned int irq = interrupt->irq;
- struct device *dev = ipa->dev;
- const struct reg *reg;
- int ret;
- interrupt->ipa = ipa;
- /* Initially all IPA interrupt types are disabled */
- interrupt->enabled = 0;
- interrupt->suspend_enabled = bitmap_zalloc(ipa->endpoint_count,
- GFP_KERNEL);
- if (!interrupt->suspend_enabled) {
- ret = -ENOMEM;
- goto err_kfree;
- }
- /* Disable IPA interrupt types */
- reg = ipa_reg(ipa, IPA_IRQ_EN);
- iowrite32(0, ipa->reg_virt + reg_offset(reg));
- ret = request_threaded_irq(irq, NULL, ipa_isr_thread, IRQF_ONESHOT,
- "ipa", interrupt);
- if (ret) {
- dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret);
- goto err_free_bitmap;
- }
- ret = device_init_wakeup(dev, true);
- if (ret) {
- dev_err(dev, "error %d enabling wakeup\n", ret);
- goto err_free_irq;
- }
- ret = dev_pm_set_wake_irq(dev, irq);
- if (ret) {
- dev_err(dev, "error %d registering \"ipa\" IRQ as wakeirq\n",
- ret);
- goto err_disable_wakeup;
- }
- ipa->interrupt = interrupt;
- return 0;
- err_disable_wakeup:
- (void)device_init_wakeup(dev, false);
- err_free_irq:
- free_irq(interrupt->irq, interrupt);
- err_free_bitmap:
- bitmap_free(interrupt->suspend_enabled);
- err_kfree:
- kfree(interrupt);
- return ret;
- }
- /* Inverse of ipa_interrupt_config() */
- void ipa_interrupt_deconfig(struct ipa *ipa)
- {
- struct ipa_interrupt *interrupt = ipa->interrupt;
- struct device *dev = ipa->dev;
- ipa->interrupt = NULL;
- dev_pm_clear_wake_irq(dev);
- (void)device_init_wakeup(dev, false);
- free_irq(interrupt->irq, interrupt);
- bitmap_free(interrupt->suspend_enabled);
- }
- /* Initialize the IPA interrupt structure */
- struct ipa_interrupt *ipa_interrupt_init(struct platform_device *pdev)
- {
- struct ipa_interrupt *interrupt;
- int irq;
- irq = platform_get_irq_byname(pdev, "ipa");
- if (irq <= 0)
- return ERR_PTR(irq ? : -EINVAL);
- interrupt = kzalloc(sizeof(*interrupt), GFP_KERNEL);
- if (!interrupt)
- return ERR_PTR(-ENOMEM);
- interrupt->irq = irq;
- return interrupt;
- }
- /* Inverse of ipa_interrupt_init() */
- void ipa_interrupt_exit(struct ipa_interrupt *interrupt)
- {
- kfree(interrupt);
- }
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