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350 lines
9.4 KiB
350 lines
9.4 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved. |
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* Copyright (C) 2019-2020 Linaro Ltd. |
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*/ |
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#include <linux/types.h> |
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#include <linux/device.h> |
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#include <linux/interrupt.h> |
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#include <linux/notifier.h> |
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#include <linux/panic_notifier.h> |
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#include <linux/pm_runtime.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 "ipa_smp2p.h" |
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#include "ipa.h" |
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#include "ipa_uc.h" |
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/** |
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* DOC: IPA SMP2P communication with the modem |
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* |
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* SMP2P is a primitive communication mechanism available between the AP and |
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* the modem. The IPA driver uses this for two purposes: to enable the modem |
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* to state that the GSI hardware is ready to use; and to communicate the |
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* state of IPA power in the event of a crash. |
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* |
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* GSI needs to have early initialization completed before it can be used. |
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* This initialization is done either by Trust Zone or by the modem. In the |
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* latter case, the modem uses an SMP2P interrupt to tell the AP IPA driver |
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* when the GSI is ready to use. |
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* |
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* The modem is also able to inquire about the current state of IPA |
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* power by trigging another SMP2P interrupt to the AP. We communicate |
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* whether power is enabled using two SMP2P state bits--one to indicate |
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* the power state (on or off), and a second to indicate the power state |
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* bit is valid. The modem will poll the valid bit until it is set, and |
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* at that time records whether the AP has IPA power enabled. |
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* |
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* Finally, if the AP kernel panics, we update the SMP2P state bits even if |
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* we never receive an interrupt from the modem requesting this. |
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*/ |
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/** |
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* struct ipa_smp2p - IPA SMP2P information |
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* @ipa: IPA pointer |
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* @valid_state: SMEM state indicating enabled state is valid |
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* @enabled_state: SMEM state to indicate power is enabled |
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* @valid_bit: Valid bit in 32-bit SMEM state mask |
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* @enabled_bit: Enabled bit in 32-bit SMEM state mask |
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* @enabled_bit: Enabled bit in 32-bit SMEM state mask |
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* @clock_query_irq: IPA interrupt triggered by modem for power query |
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* @setup_ready_irq: IPA interrupt triggered by modem to signal GSI ready |
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* @power_on: Whether IPA power is on |
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* @notified: Whether modem has been notified of power state |
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* @disabled: Whether setup ready interrupt handling is disabled |
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* @mutex: Mutex protecting ready-interrupt/shutdown interlock |
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* @panic_notifier: Panic notifier structure |
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*/ |
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struct ipa_smp2p { |
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struct ipa *ipa; |
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struct qcom_smem_state *valid_state; |
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struct qcom_smem_state *enabled_state; |
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u32 valid_bit; |
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u32 enabled_bit; |
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u32 clock_query_irq; |
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u32 setup_ready_irq; |
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bool power_on; |
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bool notified; |
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bool disabled; |
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struct mutex mutex; |
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struct notifier_block panic_notifier; |
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}; |
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/** |
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* ipa_smp2p_notify() - use SMP2P to tell modem about IPA power state |
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* @smp2p: SMP2P information |
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* |
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* This is called either when the modem has requested it (by triggering |
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* the modem power query IPA interrupt) or whenever the AP is shutting down |
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* (via a panic notifier). It sets the two SMP2P state bits--one saying |
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* whether the IPA power is on, and the other indicating the first bit |
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* is valid. |
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*/ |
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static void ipa_smp2p_notify(struct ipa_smp2p *smp2p) |
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{ |
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struct device *dev; |
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u32 value; |
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u32 mask; |
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if (smp2p->notified) |
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return; |
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dev = &smp2p->ipa->pdev->dev; |
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smp2p->power_on = pm_runtime_get_if_active(dev, true) > 0; |
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/* Signal whether the IPA power is enabled */ |
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mask = BIT(smp2p->enabled_bit); |
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value = smp2p->power_on ? mask : 0; |
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qcom_smem_state_update_bits(smp2p->enabled_state, mask, value); |
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/* Now indicate that the enabled flag is valid */ |
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mask = BIT(smp2p->valid_bit); |
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value = mask; |
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qcom_smem_state_update_bits(smp2p->valid_state, mask, value); |
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smp2p->notified = true; |
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} |
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/* Threaded IRQ handler for modem "ipa-clock-query" SMP2P interrupt */ |
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static irqreturn_t ipa_smp2p_modem_clk_query_isr(int irq, void *dev_id) |
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{ |
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struct ipa_smp2p *smp2p = dev_id; |
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ipa_smp2p_notify(smp2p); |
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return IRQ_HANDLED; |
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} |
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static int ipa_smp2p_panic_notifier(struct notifier_block *nb, |
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unsigned long action, void *data) |
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{ |
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struct ipa_smp2p *smp2p; |
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smp2p = container_of(nb, struct ipa_smp2p, panic_notifier); |
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ipa_smp2p_notify(smp2p); |
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if (smp2p->power_on) |
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ipa_uc_panic_notifier(smp2p->ipa); |
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return NOTIFY_DONE; |
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} |
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static int ipa_smp2p_panic_notifier_register(struct ipa_smp2p *smp2p) |
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{ |
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/* IPA panic handler needs to run before modem shuts down */ |
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smp2p->panic_notifier.notifier_call = ipa_smp2p_panic_notifier; |
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smp2p->panic_notifier.priority = INT_MAX; /* Do it early */ |
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return atomic_notifier_chain_register(&panic_notifier_list, |
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&smp2p->panic_notifier); |
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} |
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static void ipa_smp2p_panic_notifier_unregister(struct ipa_smp2p *smp2p) |
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{ |
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atomic_notifier_chain_unregister(&panic_notifier_list, |
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&smp2p->panic_notifier); |
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} |
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/* Threaded IRQ handler for modem "ipa-setup-ready" SMP2P interrupt */ |
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static irqreturn_t ipa_smp2p_modem_setup_ready_isr(int irq, void *dev_id) |
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{ |
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struct ipa_smp2p *smp2p = dev_id; |
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struct device *dev; |
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int ret; |
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mutex_lock(&smp2p->mutex); |
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if (smp2p->disabled) |
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goto out_mutex_unlock; |
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smp2p->disabled = true; /* If any others arrive, ignore them */ |
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/* Power needs to be active for setup */ |
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dev = &smp2p->ipa->pdev->dev; |
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ret = pm_runtime_get_sync(dev); |
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if (ret < 0) { |
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dev_err(dev, "error %d getting power for setup\n", ret); |
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goto out_power_put; |
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} |
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/* An error here won't cause driver shutdown, so warn if one occurs */ |
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ret = ipa_setup(smp2p->ipa); |
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WARN(ret != 0, "error %d from ipa_setup()\n", ret); |
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out_power_put: |
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pm_runtime_mark_last_busy(dev); |
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(void)pm_runtime_put_autosuspend(dev); |
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out_mutex_unlock: |
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mutex_unlock(&smp2p->mutex); |
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return IRQ_HANDLED; |
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} |
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/* Initialize SMP2P interrupts */ |
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static int ipa_smp2p_irq_init(struct ipa_smp2p *smp2p, const char *name, |
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irq_handler_t handler) |
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{ |
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struct device *dev = &smp2p->ipa->pdev->dev; |
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unsigned int irq; |
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int ret; |
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ret = platform_get_irq_byname(smp2p->ipa->pdev, name); |
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if (ret <= 0) |
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return ret ? : -EINVAL; |
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irq = ret; |
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ret = request_threaded_irq(irq, NULL, handler, 0, name, smp2p); |
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if (ret) { |
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dev_err(dev, "error %d requesting \"%s\" IRQ\n", ret, name); |
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return ret; |
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} |
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return irq; |
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} |
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static void ipa_smp2p_irq_exit(struct ipa_smp2p *smp2p, u32 irq) |
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{ |
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free_irq(irq, smp2p); |
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} |
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/* Drop the power reference if it was taken in ipa_smp2p_notify() */ |
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static void ipa_smp2p_power_release(struct ipa *ipa) |
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{ |
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struct device *dev = &ipa->pdev->dev; |
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if (!ipa->smp2p->power_on) |
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return; |
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pm_runtime_mark_last_busy(dev); |
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(void)pm_runtime_put_autosuspend(dev); |
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ipa->smp2p->power_on = false; |
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} |
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/* Initialize the IPA SMP2P subsystem */ |
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int ipa_smp2p_init(struct ipa *ipa, bool modem_init) |
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{ |
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struct qcom_smem_state *enabled_state; |
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struct device *dev = &ipa->pdev->dev; |
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struct qcom_smem_state *valid_state; |
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struct ipa_smp2p *smp2p; |
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u32 enabled_bit; |
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u32 valid_bit; |
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int ret; |
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valid_state = qcom_smem_state_get(dev, "ipa-clock-enabled-valid", |
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&valid_bit); |
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if (IS_ERR(valid_state)) |
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return PTR_ERR(valid_state); |
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if (valid_bit >= 32) /* BITS_PER_U32 */ |
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return -EINVAL; |
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enabled_state = qcom_smem_state_get(dev, "ipa-clock-enabled", |
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&enabled_bit); |
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if (IS_ERR(enabled_state)) |
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return PTR_ERR(enabled_state); |
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if (enabled_bit >= 32) /* BITS_PER_U32 */ |
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return -EINVAL; |
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smp2p = kzalloc(sizeof(*smp2p), GFP_KERNEL); |
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if (!smp2p) |
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return -ENOMEM; |
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smp2p->ipa = ipa; |
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/* These fields are needed by the power query interrupt |
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* handler, so initialize them now. |
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*/ |
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mutex_init(&smp2p->mutex); |
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smp2p->valid_state = valid_state; |
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smp2p->valid_bit = valid_bit; |
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smp2p->enabled_state = enabled_state; |
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smp2p->enabled_bit = enabled_bit; |
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/* We have enough information saved to handle notifications */ |
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ipa->smp2p = smp2p; |
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ret = ipa_smp2p_irq_init(smp2p, "ipa-clock-query", |
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ipa_smp2p_modem_clk_query_isr); |
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if (ret < 0) |
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goto err_null_smp2p; |
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smp2p->clock_query_irq = ret; |
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ret = ipa_smp2p_panic_notifier_register(smp2p); |
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if (ret) |
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goto err_irq_exit; |
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if (modem_init) { |
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/* Result will be non-zero (negative for error) */ |
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ret = ipa_smp2p_irq_init(smp2p, "ipa-setup-ready", |
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ipa_smp2p_modem_setup_ready_isr); |
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if (ret < 0) |
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goto err_notifier_unregister; |
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smp2p->setup_ready_irq = ret; |
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} |
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return 0; |
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err_notifier_unregister: |
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ipa_smp2p_panic_notifier_unregister(smp2p); |
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err_irq_exit: |
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ipa_smp2p_irq_exit(smp2p, smp2p->clock_query_irq); |
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err_null_smp2p: |
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ipa->smp2p = NULL; |
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mutex_destroy(&smp2p->mutex); |
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kfree(smp2p); |
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return ret; |
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} |
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void ipa_smp2p_exit(struct ipa *ipa) |
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{ |
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struct ipa_smp2p *smp2p = ipa->smp2p; |
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if (smp2p->setup_ready_irq) |
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ipa_smp2p_irq_exit(smp2p, smp2p->setup_ready_irq); |
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ipa_smp2p_panic_notifier_unregister(smp2p); |
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ipa_smp2p_irq_exit(smp2p, smp2p->clock_query_irq); |
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/* We won't get notified any more; drop power reference (if any) */ |
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ipa_smp2p_power_release(ipa); |
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ipa->smp2p = NULL; |
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mutex_destroy(&smp2p->mutex); |
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kfree(smp2p); |
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} |
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void ipa_smp2p_disable(struct ipa *ipa) |
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{ |
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struct ipa_smp2p *smp2p = ipa->smp2p; |
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if (!smp2p->setup_ready_irq) |
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return; |
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mutex_lock(&smp2p->mutex); |
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smp2p->disabled = true; |
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mutex_unlock(&smp2p->mutex); |
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} |
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/* Reset state tracking whether we have notified the modem */ |
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void ipa_smp2p_notify_reset(struct ipa *ipa) |
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{ |
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struct ipa_smp2p *smp2p = ipa->smp2p; |
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u32 mask; |
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if (!smp2p->notified) |
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return; |
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ipa_smp2p_power_release(ipa); |
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/* Reset the power enabled valid flag */ |
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mask = BIT(smp2p->valid_bit); |
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qcom_smem_state_update_bits(smp2p->valid_state, mask, 0); |
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/* Mark the power disabled for good measure... */ |
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mask = BIT(smp2p->enabled_bit); |
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qcom_smem_state_update_bits(smp2p->enabled_state, mask, 0); |
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smp2p->notified = false; |
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}
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