1 files changed, 99 insertions, 34 deletions

diff --git a/drivers/soc/qcom/smsm.c b/drivers/soc/qcom/smsm.c
index 50214b620865..021e9d1f61dc 100644
--- a/drivers/soc/qcom/smsm.c
+++ b/drivers/soc/qcom/smsm.c
@@ -1,18 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * 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/mailbox_client.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of_irq.h>
@@ -79,6 +72,7 @@ struct smsm_host;
  * @lock:	spinlock for read-modify-write of the outgoing state
  * @entries:	context for each of the entries
  * @hosts:	context for each of the hosts
+ * @mbox_client: mailbox client handle
  */
 struct qcom_smsm {
 	struct device *dev;
@@ -96,6 +90,8 @@ struct qcom_smsm {
 
 	struct smsm_entry *entries;
 	struct smsm_host *hosts;
+
+	struct mbox_client mbox_client;
 };
 
 /**
@@ -117,7 +113,7 @@ struct smsm_entry {
 	DECLARE_BITMAP(irq_enabled, 32);
 	DECLARE_BITMAP(irq_rising, 32);
 	DECLARE_BITMAP(irq_falling, 32);
-	u32 last_value;
+	unsigned long last_value;
 
 	u32 *remote_state;
 	u32 *subscription;
@@ -128,17 +124,20 @@ struct smsm_entry {
  * @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
+ * @mbox_chan:	apcs ipc mailbox channel handle
  */
 struct smsm_host {
 	struct regmap *ipc_regmap;
 	int ipc_offset;
 	int ipc_bit;
+
+	struct mbox_chan *mbox_chan;
 };
 
 /**
  * smsm_update_bits() - change bit in outgoing entry and inform subscribers
  * @data:	smsm context pointer
- * @offset:	bit in the entry
+ * @mask:	value mask
  * @value:	new value
  *
  * Used to set and clear the bits in the outgoing/local entry and inform
@@ -180,7 +179,13 @@ static int smsm_update_bits(void *data, u32 mask, u32 value)
 		hostp = &smsm->hosts[host];
 
 		val = readl(smsm->subscription + host);
-		if (val & changes && hostp->ipc_regmap) {
+		if (!(val & changes))
+			continue;
+
+		if (hostp->mbox_chan) {
+			mbox_send_message(hostp->mbox_chan, NULL);
+			mbox_client_txdone(hostp->mbox_chan, 0);
+		} else if (hostp->ipc_regmap) {
 			regmap_write(hostp->ipc_regmap,
 				     hostp->ipc_offset,
 				     BIT(hostp->ipc_bit));
@@ -212,8 +217,7 @@ static irqreturn_t smsm_intr(int irq, void *data)
 	u32 val;
 
 	val = readl(entry->remote_state);
-	changed = val ^ entry->last_value;
-	entry->last_value = val;
+	changed = val ^ xchg(&entry->last_value, val);
 
 	for_each_set_bit(i, entry->irq_enabled, 32) {
 		if (!(changed & BIT(i)))
@@ -262,10 +266,8 @@ static void smsm_mask_irq(struct irq_data *irqd)
  * 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)
 {
@@ -274,6 +276,12 @@ static void smsm_unmask_irq(struct irq_data *irqd)
 	struct qcom_smsm *smsm = entry->smsm;
 	u32 val;
 
+	/* Make sure our last cached state is up-to-date */
+	if (readl(entry->remote_state) & BIT(irq))
+		set_bit(irq, &entry->last_value);
+	else
+		clear_bit(irq, &entry->last_value);
+
 	set_bit(irq, entry->irq_enabled);
 
 	if (entry->subscription) {
@@ -309,11 +317,28 @@ static int smsm_set_irq_type(struct irq_data *irqd, unsigned int type)
 	return 0;
 }
 
+static int smsm_get_irqchip_state(struct irq_data *irqd,
+				  enum irqchip_irq_state which, bool *state)
+{
+	struct smsm_entry *entry = irq_data_get_irq_chip_data(irqd);
+	irq_hw_number_t irq = irqd_to_hwirq(irqd);
+	u32 val;
+
+	if (which != IRQCHIP_STATE_LINE_LEVEL)
+		return -EINVAL;
+
+	val = readl(entry->remote_state);
+	*state = !!(val & BIT(irq));
+
+	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,
+	.irq_get_irqchip_state = smsm_get_irqchip_state,
 };
 
 /**
@@ -341,6 +366,28 @@ static const struct irq_domain_ops smsm_irq_ops = {
 };
 
 /**
+ * smsm_parse_mbox() - requests an mbox channel
+ * @smsm:	smsm driver context
+ * @host_id:	index of the remote host to be resolved
+ *
+ * Requests the desired channel using the mbox interface which is needed for
+ * sending the outgoing interrupts to a remove hosts - identified by @host_id.
+ */
+static int smsm_parse_mbox(struct qcom_smsm *smsm, unsigned int host_id)
+{
+	struct smsm_host *host = &smsm->hosts[host_id];
+	int ret = 0;
+
+	host->mbox_chan = mbox_request_channel(&smsm->mbox_client, host_id);
+	if (IS_ERR(host->mbox_chan)) {
+		ret = PTR_ERR(host->mbox_chan);
+		host->mbox_chan = NULL;
+	}
+
+	return ret;
+}
+
+/**
  * 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
@@ -362,6 +409,7 @@ static int smsm_parse_ipc(struct qcom_smsm *smsm, unsigned host_id)
 		return 0;
 
 	host->ipc_regmap = syscon_node_to_regmap(syscon);
+	of_node_put(syscon);
 	if (IS_ERR(host->ipc_regmap))
 		return PTR_ERR(host->ipc_regmap);
 
@@ -408,7 +456,7 @@ static int smsm_inbound_entry(struct qcom_smsm *smsm,
 		return ret;
 	}
 
-	entry->domain = irq_domain_add_linear(node, 32, &smsm_irq_ops, entry);
+	entry->domain = irq_domain_create_linear(of_fwnode_handle(node), 32, &smsm_irq_ops, entry);
 	if (!entry->domain) {
 		dev_err(smsm->dev, "failed to add irq_domain\n");
 		return -ENOMEM;
@@ -439,11 +487,10 @@ static int smsm_get_size_info(struct qcom_smsm *smsm)
 	} *info;
 
 	info = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_SMSM_SIZE_INFO, &size);
-	if (IS_ERR(info) && PTR_ERR(info) != -ENOENT) {
-		if (PTR_ERR(info) != -EPROBE_DEFER)
-			dev_err(smsm->dev, "unable to retrieve smsm size info\n");
-		return PTR_ERR(info);
-	} else if (IS_ERR(info) || size != sizeof(*info)) {
+	if (IS_ERR(info) && PTR_ERR(info) != -ENOENT)
+		return dev_err_probe(smsm->dev, PTR_ERR(info),
+				     "unable to retrieve smsm size info\n");
+	else if (IS_ERR(info) || 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;
@@ -497,7 +544,7 @@ static int qcom_smsm_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	for_each_child_of_node(pdev->dev.of_node, local_node) {
-		if (of_find_property(local_node, "#qcom,smem-state-cells", NULL))
+		if (of_property_present(local_node, "#qcom,smem-state-cells"))
 			break;
 	}
 	if (!local_node) {
@@ -509,11 +556,19 @@ static int qcom_smsm_probe(struct platform_device *pdev)
 			     "qcom,local-host",
 			     &smsm->local_host);
 
+	smsm->mbox_client.dev = &pdev->dev;
+	smsm->mbox_client.knows_txdone = true;
+
 	/* Parse the host properties */
 	for (id = 0; id < smsm->num_hosts; id++) {
+		/* Try using mbox interface first, otherwise fall back to syscon */
+		ret = smsm_parse_mbox(smsm, id);
+		if (!ret)
+			continue;
+
 		ret = smsm_parse_ipc(smsm, id);
 		if (ret < 0)
-			return ret;
+			goto out_put;
 	}
 
 	/* Acquire the main SMSM state vector */
@@ -521,13 +576,14 @@ static int qcom_smsm_probe(struct platform_device *pdev)
 			      smsm->num_entries * sizeof(u32));
 	if (ret < 0 && ret != -EEXIST) {
 		dev_err(&pdev->dev, "unable to allocate shared state entry\n");
-		return ret;
+		goto out_put;
 	}
 
 	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);
+		ret = PTR_ERR(states);
+		goto out_put;
 	}
 
 	/* Acquire the list of interrupt mask vectors */
@@ -535,13 +591,14 @@ static int qcom_smsm_probe(struct platform_device *pdev)
 	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;
+		goto out_put;
 	}
 
 	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);
+		ret = PTR_ERR(intr_mask);
+		goto out_put;
 	}
 
 	/* Setup the reference to the local state bits */
@@ -552,7 +609,8 @@ static int qcom_smsm_probe(struct platform_device *pdev)
 	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);
+		ret = PTR_ERR(smsm->state);
+		goto out_put;
 	}
 
 	/* Register handlers for remote processor entries of interest. */
@@ -582,20 +640,26 @@ static int qcom_smsm_probe(struct platform_device *pdev)
 	}
 
 	platform_set_drvdata(pdev, smsm);
+	of_node_put(local_node);
 
 	return 0;
 
 unwind_interfaces:
+	of_node_put(node);
 	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);
+out_put:
+	for (id = 0; id < smsm->num_hosts; id++)
+		mbox_free_channel(smsm->hosts[id].mbox_chan);
 
+	of_node_put(local_node);
 	return ret;
 }
 
-static int qcom_smsm_remove(struct platform_device *pdev)
+static void qcom_smsm_remove(struct platform_device *pdev)
 {
 	struct qcom_smsm *smsm = platform_get_drvdata(pdev);
 	unsigned id;
@@ -604,9 +668,10 @@ static int qcom_smsm_remove(struct platform_device *pdev)
 		if (smsm->entries[id].domain)
 			irq_domain_remove(smsm->entries[id].domain);
 
-	qcom_smem_state_unregister(smsm->state);
+	for (id = 0; id < smsm->num_hosts; id++)
+		mbox_free_channel(smsm->hosts[id].mbox_chan);
 
-	return 0;
+	qcom_smem_state_unregister(smsm->state);
 }
 
 static const struct of_device_id qcom_smsm_of_match[] = {
@@ -618,8 +683,8 @@ 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",
+	.driver = {
+		.name = "qcom-smsm",
 		.of_match_table = qcom_smsm_of_match,
 	},
 };