[RFC PATCH 22/31] xen/arm: Add Xen changes to SCPI protocol

[Oleksandr Tyshchenko <olekstysh@gmail.com>]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>

Modify the direct ported SCPI Message Protocol driver to be
functional inside Xen.

As SCPI Message protocol driver expects mailbox to be registed,
find and initialize mailbox before probing it.

Include "wrappers.h" which contains all required things the direct
ported code relies on.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Julien Grall <julien.grall@linaro.org>
---
 xen/arch/arm/cpufreq/arm_scpi.c      | 90 ++++++++++++++++++++++++++++++++++++
 xen/arch/arm/cpufreq/scpi_protocol.h | 32 +++++++++++++
 2 files changed, 122 insertions(+)

diff --git a/xen/arch/arm/cpufreq/arm_scpi.c b/xen/arch/arm/cpufreq/arm_scpi.c
index 7da9f1b..553a516 100644
--- a/xen/arch/arm/cpufreq/arm_scpi.c
+++ b/xen/arch/arm/cpufreq/arm_scpi.c
@@ -23,8 +23,16 @@
  *
  * You should have received a copy of the GNU General Public License along
  * with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Based on Linux drivers/firmware/arm_scpi.c
+ * => commit 0d30176819c8738b012ec623c7b3db19df818e70
+ *
+ * Xen modification:
+ * Oleksandr Tyshchenko <Oleksandr_Tyshchenko@epam.com>
+ * Copyright (C) 2017 EPAM Systems Inc.
  */
 
+#if 0
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/bitmap.h>
@@ -44,6 +52,22 @@
 #include <linux/slab.h>
 #include <linux/sort.h>
 #include <linux/spinlock.h>
+#endif
+
+#include <xen/device_tree.h>
+#include <xen/err.h>
+#include <xen/vmap.h>
+#include <xen/sort.h>
+
+#include "scpi_protocol.h"
+#include "mailbox_client.h"
+#include "mailbox_controller.h"
+#include "wrappers.h"
+
+/*
+ * TODO:
+ * 1. Add releasing resources since devm.
+ */
 
 #define CMD_ID_SHIFT		0
 #define CMD_ID_MASK		0x7f
@@ -859,6 +883,7 @@ static int scpi_init_versions(struct scpi_drvinfo *info)
 	return ret;
 }
 
+#if 0
 static ssize_t protocol_version_show(struct device *dev,
 				     struct device_attribute *attr, char *buf)
 {
@@ -888,6 +913,7 @@ static struct attribute *versions_attrs[] = {
 	NULL,
 };
 ATTRIBUTE_GROUPS(versions);
+#endif
 
 static void
 scpi_free_channels(struct device *dev, struct scpi_chan *pchan, int count)
@@ -909,8 +935,10 @@ static int scpi_remove(struct platform_device *pdev)
 
 	scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
 
+#if 0
 	of_platform_depopulate(dev);
 	sysfs_remove_groups(&dev->kobj, versions_groups);
+#endif
 	scpi_free_channels(dev, info->channels, info->num_chans);
 	platform_set_drvdata(pdev, NULL);
 
@@ -1055,11 +1083,15 @@ err:
 		  FW_REV_PATCH(scpi_info->firmware_version));
 	scpi_info->scpi_ops = &scpi_ops;
 
+#if 0
 	ret = sysfs_create_groups(&dev->kobj, versions_groups);
 	if (ret)
 		dev_err(dev, "unable to create sysfs version group\n");
 
 	return of_platform_populate(dev->of_node, NULL, NULL, dev);
+#else
+	return 0;
+#endif
 }
 
 static const struct of_device_id scpi_of_match[] = {
@@ -1070,6 +1102,7 @@ static const struct of_device_id scpi_of_match[] = {
 
 MODULE_DEVICE_TABLE(of, scpi_of_match);
 
+#if 0
 static struct platform_driver scpi_driver = {
 	.driver = {
 		.name = "scpi_protocol",
@@ -1083,3 +1116,60 @@ module_platform_driver(scpi_driver);
 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
 MODULE_LICENSE("GPL v2");
+#endif
+
+static struct device *scpi_dev;
+
+struct device *get_scpi_dev(void)
+{
+	return scpi_dev;
+}
+
+int __init scpi_init(void)
+{
+	struct dt_device_node *scpi, *mbox;
+	bool has_mbox = false;
+	int ret = -ENODEV;
+
+	scpi = dt_find_matching_node(NULL, scpi_of_match);
+	if (!scpi) {
+		printk("failed to find SCPI node in the device tree\n");
+		return -ENXIO;
+	}
+
+	/* At first find and initialize mailbox to communicate with SCP */
+	dt_for_each_device_node(dt_host, mbox) {
+		ret = device_init(mbox, DEVICE_MAILBOX, NULL);
+		if (!ret) {
+			has_mbox = true;
+			break;
+		}
+	}
+
+	if (!has_mbox) {
+		dev_err(&scpi->dev, "failed to init Mailbox interface (%d)\n", ret);
+		return ret;
+	}
+
+	ret = scpi_probe(scpi);
+	if (ret) {
+		/* TODO Do we need to deinit mailbox? */
+		dev_err(&scpi->dev, "failed to init SCPI Message Protocol (%d)\n", ret);
+		return ret;
+	}
+
+	scpi_dev = &scpi->dev;
+
+	/* TODO Do we need to mark device as used by Xen? */
+
+	return 0;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 8
+ * indent-tabs-mode: t
+ * End:
+ */
diff --git a/xen/arch/arm/cpufreq/scpi_protocol.h b/xen/arch/arm/cpufreq/scpi_protocol.h
index 327d656..0f6dab3 100644
--- a/xen/arch/arm/cpufreq/scpi_protocol.h
+++ b/xen/arch/arm/cpufreq/scpi_protocol.h
@@ -14,8 +14,25 @@
  *
  * You should have received a copy of the GNU General Public License along with
  * this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Based on Linux include/linux/scpi_protocol.h
+ * => commit 45ca7df7c345465dbd2426a33012c9c33d27de62
+ *
+ * Xen modification:
+ * Oleksandr Tyshchenko <Oleksandr_Tyshchenko@epam.com>
+ * Copyright (C) 2017 EPAM Systems Inc.
  */
+
+#ifndef __ARCH_ARM_CPUFREQ_SCPI_PROTOCOL_H__
+#define __ARCH_ARM_CPUFREQ_SCPI_PROTOCOL_H__
+
+#if 0
 #include <linux/types.h>
+#endif
+
+#include <asm/device.h>
+
+#define IS_REACHABLE(CONFIG_ARM_SCPI_PROTOCOL) 1
 
 struct scpi_opp {
 	u32 freq;
@@ -78,7 +95,22 @@ struct scpi_ops {
 };
 
 #if IS_REACHABLE(CONFIG_ARM_SCPI_PROTOCOL)
+int scpi_init(void);
+struct device *get_scpi_dev(void);
 struct scpi_ops *get_scpi_ops(void);
 #else
+static inline int scpi_init(void) { return -1; }
+static inline struct device *get_scpi_dev(void) { return NULL; }
 static inline struct scpi_ops *get_scpi_ops(void) { return NULL; }
 #endif
+
+#endif /* __ARCH_ARM_CPUFREQ_SCPI_PROTOCOL_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 8
+ * indent-tabs-mode: t
+ * End:
+ */
-- 
2.7.4


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