[PATCH 13/21] platform: goldfish: pipe: Split the driver to v2 specific and the rest

From: rkir
Date: Fri Sep 14 2018 - 13:52:48 EST

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From: Roman Kiryanov <rkir@xxxxxxxxxx>

Move probe/remove and other driver stuff to a separate file
to plug v1 there later.

Signed-off-by: Roman Kiryanov <rkir@xxxxxxxxxx>
---
drivers/platform/goldfish/Makefile | 2 +-
drivers/platform/goldfish/goldfish_pipe.c | 145 +++++++++++++++++++
drivers/platform/goldfish/goldfish_pipe.h | 24 +++
drivers/platform/goldfish/goldfish_pipe_v2.c | 102 ++-----------
drivers/platform/goldfish/goldfish_pipe_v2.h | 24 +++
5 files changed, 209 insertions(+), 88 deletions(-)
create mode 100644 drivers/platform/goldfish/goldfish_pipe.c
create mode 100644 drivers/platform/goldfish/goldfish_pipe.h
create mode 100644 drivers/platform/goldfish/goldfish_pipe_v2.h

diff --git a/drivers/platform/goldfish/Makefile b/drivers/platform/goldfish/Makefile
index 81f899a987a2..6a9f6e6de46d 100644
--- a/drivers/platform/goldfish/Makefile
+++ b/drivers/platform/goldfish/Makefile
@@ -1,4 +1,4 @@
#
# Makefile for Goldfish platform specific drivers
#
-obj-$(CONFIG_GOLDFISH_PIPE) += goldfish_pipe_v2.o
+obj-$(CONFIG_GOLDFISH_PIPE) += goldfish_pipe.o goldfish_pipe_v2.o
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
new file mode 100644
index 000000000000..802bbf0d6d23
--- /dev/null
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012 Intel, Inc.
+ * Copyright (C) 2013 Intel, Inc.
+ * Copyright (C) 2014 Linaro Limited
+ * Copyright (C) 2011-2016 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+/* This source file contains the implementation of a special device driver
+ * that intends to provide a *very* fast communication channel between the
+ * guest system and the QEMU emulator.
+ *
+ * Usage from the guest is simply the following (error handling simplified):
+ *
+ * int fd = open("/dev/qemu_pipe",O_RDWR);
+ * .... write() or read() through the pipe.
+ *
+ * This driver doesn't deal with the exact protocol used during the session.
+ * It is intended to be as simple as something like:
+ *
+ * // do this _just_ after opening the fd to connect to a specific
+ * // emulator service.
+ * const char* msg = "<pipename>";
+ * if (write(fd, msg, strlen(msg)+1) < 0) {
+ * ... could not connect to <pipename> service
+ * close(fd);
+ * }
+ *
+ * // after this, simply read() and write() to communicate with the
+ * // service. Exact protocol details left as an exercise to the reader.
+ *
+ * This driver is very fast because it doesn't copy any data through
+ * intermediate buffers, since the emulator is capable of translating
+ * guest user addresses into host ones.
+ *
+ * Note that we must however ensure that each user page involved in the
+ * exchange is properly mapped during a transfer.
+ */
+
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/acpi.h>
+#include "goldfish_pipe_qemu.h"
+#include "goldfish_pipe.h"
+#include "goldfish_pipe_v2.h"
+
+/*
+ * Update this when something changes in the driver's behavior so the host
+ * can benefit from knowing it
+ * Notes:
+ * version 2 was an intermediate release and isn't supported anymore.
+ * version 3 is goldfish_pipe_v2 without DMA support.
+ * version 4 (current) is goldfish_pipe_v2 with DMA support.
+ */
+enum {
+ PIPE_DRIVER_VERSION = 4,
+ PIPE_CURRENT_DEVICE_VERSION = 2
+};
+
+static int goldfish_pipe_probe(struct platform_device *pdev)
+{
+ struct resource *r;
+ char __iomem *base;
+ int irq;
+ int version;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r || resource_size(r) < PAGE_SIZE) {
+ dev_err(&pdev->dev, "can't allocate i/o page\n");
+ return -EINVAL;
+ }
+ base = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
+ if (!base) {
+ dev_err(&pdev->dev, "ioremap failed\n");
+ return -EINVAL;
+ }
+
+ r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!r)
+ return -EINVAL;
+
+ irq = r->start;
+
+ /*
+ * Exchange the versions with the host device
+ *
+ * Note: v1 driver used to not report its version, so we write it before
+ * reading device version back: this allows the host implementation to
+ * detect the old driver (if there was no version write before read).
+ */
+ writel((u32)PIPE_DRIVER_VERSION, base + PIPE_REG_VERSION);
+ version = readl(base + PIPE_REG_VERSION);
+
+ if (WARN_ON(version < PIPE_CURRENT_DEVICE_VERSION))
+ return -EINVAL;
+
+ return goldfish_pipe_device_init(pdev, base, irq);
+}
+
+static int goldfish_pipe_remove(struct platform_device *pdev)
+{
+ struct goldfish_pipe_dev_base *dev = platform_get_drvdata(pdev);
+
+ return dev->deinit(dev, pdev);
+}
+
+static const struct acpi_device_id goldfish_pipe_acpi_match[] = {
+ { "GFSH0003", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, goldfish_pipe_acpi_match);
+
+static const struct of_device_id goldfish_pipe_of_match[] = {
+ { .compatible = "google,android-pipe", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, goldfish_pipe_of_match);
+
+static struct platform_driver goldfish_pipe_driver = {
+ .probe = goldfish_pipe_probe,
+ .remove = goldfish_pipe_remove,
+ .driver = {
+ .name = "goldfish_pipe",
+ .of_match_table = goldfish_pipe_of_match,
+ .acpi_match_table = ACPI_PTR(goldfish_pipe_acpi_match),
+ }
+};
+
+module_platform_driver(goldfish_pipe_driver);
+MODULE_AUTHOR("David Turner <digit@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/platform/goldfish/goldfish_pipe.h b/drivers/platform/goldfish/goldfish_pipe.h
new file mode 100644
index 000000000000..41e831f59eff
--- /dev/null
+++ b/drivers/platform/goldfish/goldfish_pipe.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#ifndef GOLDFISH_PIPE_H
+#define GOLDFISH_PIPE_H
+
+struct goldfish_pipe_dev_base {
+ /* the destructor, the pointer is set in init */
+ int (*deinit)(void *pipe_dev, struct platform_device *pdev);
+};
+
+#endif /* GOLDFISH_PIPE_H */
diff --git a/drivers/platform/goldfish/goldfish_pipe_v2.c b/drivers/platform/goldfish/goldfish_pipe_v2.c
index 7187b2e603d4..d653e5a2ffcc 100644
--- a/drivers/platform/goldfish/goldfish_pipe_v2.c
+++ b/drivers/platform/goldfish/goldfish_pipe_v2.c
@@ -47,8 +47,6 @@
* exchange is properly mapped during a transfer.
*/

-#include <linux/module.h>
-#include <linux/mod_devicetable.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
@@ -61,10 +59,10 @@
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <linux/mm.h>
-#include <linux/acpi.h>
#include <linux/bug.h>
#include <uapi/linux/goldfish/goldfish_dma.h>
#include "goldfish_pipe_qemu.h"
+#include "goldfish_pipe.h"

/*
* Update this when something changes in the driver's behavior so the host
@@ -89,6 +87,9 @@ enum {

struct goldfish_pipe_dev;

+static int goldfish_pipe_device_deinit(void *raw_dev,
+ struct platform_device *pdev);
+
/* A per-pipe command structure, shared with the host */
struct goldfish_pipe_command {
s32 cmd; /* PipeCmdCode, guest -> host */
@@ -202,8 +203,8 @@ struct goldfish_pipe {
* waiting to be awoken.
*/
struct goldfish_pipe_dev {
- /* A magic number to check if this is an instance of this struct */
- void *magic;
+ /* Needed for 'remove' */
+ struct goldfish_pipe_dev_base super;

/*
* Global device spinlock. Protects the following members:
@@ -646,9 +647,6 @@ static void goldfish_interrupt_task(unsigned long dev_addr)
}
}

-static void goldfish_pipe_device_deinit(struct platform_device *pdev,
- struct goldfish_pipe_dev *dev);
-
/*
* The general idea of the interrupt handling:
*
@@ -669,7 +667,7 @@ static irqreturn_t goldfish_pipe_interrupt(int irq, void *dev_id)
unsigned long flags;
struct goldfish_pipe_dev *dev = dev_id;

- if (dev->magic != &goldfish_pipe_device_deinit)
+ if (dev->super.deinit != &goldfish_pipe_device_deinit)
return IRQ_NONE;

/* Request the signalled pipes from the device */
@@ -1122,9 +1120,9 @@ static void write_pa_addr(void *addr, void __iomem *portl, void __iomem *porth)
writel(lower_32_bits(paddr), portl);
}

-static int goldfish_pipe_device_init(struct platform_device *pdev,
- char __iomem *base,
- int irq)
+int goldfish_pipe_device_init(struct platform_device *pdev,
+ char __iomem *base,
+ int irq)
{
struct goldfish_pipe_dev *dev;
int err;
@@ -1133,7 +1131,7 @@ static int goldfish_pipe_device_init(struct platform_device *pdev,
if (!dev)
return -ENOMEM;

- dev->magic = &goldfish_pipe_device_deinit;
+ dev->super.deinit = &goldfish_pipe_device_deinit;
spin_lock_init(&dev->lock);

tasklet_init(&dev->irq_tasklet, &goldfish_interrupt_task,
@@ -1193,9 +1191,11 @@ static int goldfish_pipe_device_init(struct platform_device *pdev,
return 0;
}

-static int goldfish_pipe_device_deinit(struct platform_device *pdev,
- struct goldfish_pipe_dev *dev)
+static int goldfish_pipe_device_deinit(void *raw_dev,
+ struct platform_device *pdev)
{
+ struct goldfish_pipe_dev *dev = raw_dev;
+
misc_deregister(&dev->miscdev);
tasklet_kill(&dev->irq_tasklet);
kfree(dev->pipes);
@@ -1203,75 +1203,3 @@ static int goldfish_pipe_device_deinit(struct platform_device *pdev,

return 0;
}
-
-static int goldfish_pipe_probe(struct platform_device *pdev)
-{
- struct resource *r;
- char __iomem *base;
- int irq;
- int version;
-
- r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!r || resource_size(r) < PAGE_SIZE) {
- dev_err(&pdev->dev, "can't allocate i/o page\n");
- return -EINVAL;
- }
- base = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
- if (!base) {
- dev_err(&pdev->dev, "ioremap failed\n");
- return -EINVAL;
- }
-
- r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
- if (!r)
- return -EINVAL;
-
- irq = r->start;
-
- /*
- * Exchange the versions with the host device
- *
- * Note: v1 driver used to not report its version, so we write it before
- * reading device version back: this allows the host implementation to
- * detect the old driver (if there was no version write before read).
- */
- writel((u32)PIPE_DRIVER_VERSION, base + PIPE_REG_VERSION);
- version = readl(base + PIPE_REG_VERSION);
- if (WARN_ON(version < PIPE_CURRENT_DEVICE_VERSION))
- return -EINVAL;
-
- return goldfish_pipe_device_init(pdev, base, irq);
-}
-
-static int goldfish_pipe_remove(struct platform_device *pdev)
-{
- struct goldfish_pipe_dev *dev = platform_get_drvdata(pdev);
-
- return goldfish_pipe_device_deinit(pdev, dev);
-}
-
-static const struct acpi_device_id goldfish_pipe_acpi_match[] = {
- { "GFSH0003", 0 },
- { },
-};
-MODULE_DEVICE_TABLE(acpi, goldfish_pipe_acpi_match);
-
-static const struct of_device_id goldfish_pipe_of_match[] = {
- { .compatible = "google,android-pipe", },
- {},
-};
-MODULE_DEVICE_TABLE(of, goldfish_pipe_of_match);
-
-static struct platform_driver goldfish_pipe_driver = {
- .probe = goldfish_pipe_probe,
- .remove = goldfish_pipe_remove,
- .driver = {
- .name = "goldfish_pipe",
- .of_match_table = goldfish_pipe_of_match,
- .acpi_match_table = ACPI_PTR(goldfish_pipe_acpi_match),
- }
-};
-
-module_platform_driver(goldfish_pipe_driver);
-MODULE_AUTHOR("David Turner <digit@xxxxxxxxxx>");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/platform/goldfish/goldfish_pipe_v2.h b/drivers/platform/goldfish/goldfish_pipe_v2.h
new file mode 100644
index 000000000000..679d863774a8
--- /dev/null
+++ b/drivers/platform/goldfish/goldfish_pipe_v2.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#ifndef GOLDFISH_PIPE_V2_H
+#define GOLDFISH_PIPE_V2_H
+
+/* The entry point to the pipe v2 driver */
+int goldfish_pipe_device_init(struct platform_device *pdev,
+ char __iomem *base,
+ int irq);
+
+#endif /* #define GOLDFISH_PIPE_V2_H */
--
2.19.0.397.gdd90340f6a-goog

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