2021-07-23 05:47:47

by Jie Deng

[permalink] [raw]
Subject: [PATCH v15] i2c: virtio: add a virtio i2c frontend driver

Add an I2C bus driver for virtio para-virtualization.

The controller can be emulated by the backend driver in
any device model software by following the virtio protocol.

The device specification can be found on
https://lists.oasis-open.org/archives/virtio-comment/202101/msg00008.html.

By following the specification, people may implement different
backend drivers to emulate different controllers according to
their needs.

Co-developed-by: Conghui Chen <[email protected]>
Signed-off-by: Conghui Chen <[email protected]>
Signed-off-by: Jie Deng <[email protected]>
Reviewed-by: Viresh Kumar <[email protected]>
Tested-by: Viresh Kumar <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
---
Changes v14 -> v15
- Minor fixes in Makefile and Kconfig.
- Add an i2c_adapter_quirks to filter out 0 length messages.
- Update the MAINTAINERS.

Changes v13 -> v14
- Put the headers in virtio_i2c.h in alphabetical order.
- Dropped I2C_FUNC_SMBUS_QUICK support.
- Dropped few unnecessary variables and checks.
- Use "num" everywhere instead of num or nr, to be consistent.
- Added few comments which make the design more clear.

Changes v12 -> v13
- Use _BITUL() instead of BIT().
- Rename "virtio_i2c_send_reqs" to "virtio_i2c_prepare_reqs".
- Optimize the return value of "virtio_i2c_complete_reqs".

Changes v11 -> v12
- Do not sent msg_buf for zero-length request.
- Send requests to host only if all the number of transfers requested prepared successfully.
- Remove the line #include <linux/bits.h> in virtio_i2c.h.

Changes v10 -> v11
- Remove vi->adap.class = I2C_CLASS_DEPRECATED.
- Use #ifdef CONFIG_PM_SLEEP to replace the "__maybe_unused".
- Remove "struct mutex lock" in "struct virtio_i2c".
- Support zero-length request.
- Remove unnecessary logs.
- Remove vi->adap.timeout = HZ / 10, just use the default value.
- Use BIT(0) to define VIRTIO_I2C_FLAGS_FAIL_NEXT.
- Add the virtio_device index to adapter's naming mechanism.

MAINTAINERS | 9 ++
drivers/i2c/busses/Kconfig | 11 ++
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-virtio.c | 290 ++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/virtio_i2c.h | 41 ++++++
include/uapi/linux/virtio_ids.h | 1 +
6 files changed, 353 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-virtio.c
create mode 100644 include/uapi/linux/virtio_i2c.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 6c8be73..0183c50 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19707,6 +19707,15 @@ S: Maintained
F: include/uapi/linux/virtio_snd.h
F: sound/virtio/*

+VIRTIO I2C DRIVER
+M: Jie Deng <[email protected]>
+M: Viresh Kumar <[email protected]>
+L: [email protected]
+L: [email protected]
+S: Maintained
+F: drivers/i2c/busses/i2c-virtio.c
+F: include/uapi/linux/virtio_i2c.h
+
VIRTUAL BOX GUEST DEVICE DRIVER
M: Hans de Goede <[email protected]>
M: Arnd Bergmann <[email protected]>
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 10acece..cbaf199 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1402,4 +1402,15 @@ config I2C_FSI
This driver can also be built as a module. If so, the module will be
called as i2c-fsi.

+config I2C_VIRTIO
+ tristate "Virtio I2C Adapter"
+ select VIRTIO
+ help
+ If you say yes to this option, support will be included for the virtio
+ I2C adapter driver. The hardware can be emulated by any device model
+ software according to the virtio protocol.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-virtio.
+
endmenu
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 69e9963..1e8c0ba 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -146,5 +146,6 @@ obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o
obj-$(CONFIG_I2C_XGENE_SLIMPRO) += i2c-xgene-slimpro.o
obj-$(CONFIG_SCx200_ACB) += scx200_acb.o
obj-$(CONFIG_I2C_FSI) += i2c-fsi.o
+obj-$(CONFIG_I2C_VIRTIO) += i2c-virtio.o

ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
diff --git a/drivers/i2c/busses/i2c-virtio.c b/drivers/i2c/busses/i2c-virtio.c
new file mode 100644
index 0000000..d3e60d9
--- /dev/null
+++ b/drivers/i2c/busses/i2c-virtio.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Virtio I2C Bus Driver
+ *
+ * The Virtio I2C Specification:
+ * https://raw.githubusercontent.com/oasis-tcs/virtio-spec/master/virtio-i2c.tex
+ *
+ * Copyright (c) 2021 Intel Corporation. All rights reserved.
+ */
+
+#include <linux/acpi.h>
+#include <linux/completion.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/virtio.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_i2c.h>
+
+/**
+ * struct virtio_i2c - virtio I2C data
+ * @vdev: virtio device for this controller
+ * @completion: completion of virtio I2C message
+ * @adap: I2C adapter for this controller
+ * @vq: the virtio virtqueue for communication
+ */
+struct virtio_i2c {
+ struct virtio_device *vdev;
+ struct completion completion;
+ struct i2c_adapter adap;
+ struct virtqueue *vq;
+};
+
+/**
+ * struct virtio_i2c_req - the virtio I2C request structure
+ * @out_hdr: the OUT header of the virtio I2C message
+ * @buf: the buffer into which data is read, or from which it's written
+ * @in_hdr: the IN header of the virtio I2C message
+ */
+struct virtio_i2c_req {
+ struct virtio_i2c_out_hdr out_hdr ____cacheline_aligned;
+ uint8_t *buf ____cacheline_aligned;
+ struct virtio_i2c_in_hdr in_hdr ____cacheline_aligned;
+};
+
+static void virtio_i2c_msg_done(struct virtqueue *vq)
+{
+ struct virtio_i2c *vi = vq->vdev->priv;
+
+ complete(&vi->completion);
+}
+
+static int virtio_i2c_prepare_reqs(struct virtqueue *vq,
+ struct virtio_i2c_req *reqs,
+ struct i2c_msg *msgs, int num)
+{
+ struct scatterlist *sgs[3], out_hdr, msg_buf, in_hdr;
+ int i;
+
+ for (i = 0; i < num; i++) {
+ int outcnt = 0, incnt = 0;
+
+ /*
+ * We don't support 0 length messages and so filter out
+ * 0 length transfers by using i2c_adapter_quirks.
+ */
+ if (!msgs[i].len)
+ break;
+
+ /*
+ * Only 7-bit mode supported for this moment. For the address
+ * format, Please check the Virtio I2C Specification.
+ */
+ reqs[i].out_hdr.addr = cpu_to_le16(msgs[i].addr << 1);
+
+ if (i != num - 1)
+ reqs[i].out_hdr.flags = cpu_to_le32(VIRTIO_I2C_FLAGS_FAIL_NEXT);
+
+ sg_init_one(&out_hdr, &reqs[i].out_hdr, sizeof(reqs[i].out_hdr));
+ sgs[outcnt++] = &out_hdr;
+
+ reqs[i].buf = i2c_get_dma_safe_msg_buf(&msgs[i], 1);
+ if (!reqs[i].buf)
+ break;
+
+ sg_init_one(&msg_buf, reqs[i].buf, msgs[i].len);
+
+ if (msgs[i].flags & I2C_M_RD)
+ sgs[outcnt + incnt++] = &msg_buf;
+ else
+ sgs[outcnt++] = &msg_buf;
+
+ sg_init_one(&in_hdr, &reqs[i].in_hdr, sizeof(reqs[i].in_hdr));
+ sgs[outcnt + incnt++] = &in_hdr;
+
+ if (virtqueue_add_sgs(vq, sgs, outcnt, incnt, &reqs[i], GFP_KERNEL)) {
+ i2c_put_dma_safe_msg_buf(reqs[i].buf, &msgs[i], false);
+ break;
+ }
+ }
+
+ return i;
+}
+
+static int virtio_i2c_complete_reqs(struct virtqueue *vq,
+ struct virtio_i2c_req *reqs,
+ struct i2c_msg *msgs, int num,
+ bool timedout)
+{
+ struct virtio_i2c_req *req;
+ bool failed = timedout;
+ unsigned int len;
+ int i, j = 0;
+
+ for (i = 0; i < num; i++) {
+ /* Detach the ith request from the vq */
+ req = virtqueue_get_buf(vq, &len);
+
+ /*
+ * Condition req == &reqs[i] should always meet since we have
+ * total num requests in the vq. reqs[i] can never be NULL here.
+ */
+ if (!failed && (WARN_ON(req != &reqs[i]) ||
+ req->in_hdr.status != VIRTIO_I2C_MSG_OK))
+ failed = true;
+
+ i2c_put_dma_safe_msg_buf(reqs[i].buf, &msgs[i], !failed);
+
+ if (!failed)
+ j++;
+ }
+
+ return timedout ? -ETIMEDOUT : j;
+}
+
+static int virtio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ struct virtio_i2c *vi = i2c_get_adapdata(adap);
+ struct virtqueue *vq = vi->vq;
+ struct virtio_i2c_req *reqs;
+ unsigned long time_left;
+ int count;
+
+ reqs = kcalloc(num, sizeof(*reqs), GFP_KERNEL);
+ if (!reqs)
+ return -ENOMEM;
+
+ count = virtio_i2c_prepare_reqs(vq, reqs, msgs, num);
+ if (!count)
+ goto err_free;
+
+ /*
+ * For the case where count < num, i.e. we weren't able to queue all the
+ * msgs, ideally we should abort right away and return early, but some
+ * of the messages are already sent to the remote I2C controller and the
+ * virtqueue will be left in undefined state in that case. We kick the
+ * remote here to clear the virtqueue, so we can try another set of
+ * messages later on.
+ */
+
+ reinit_completion(&vi->completion);
+ virtqueue_kick(vq);
+
+ time_left = wait_for_completion_timeout(&vi->completion, adap->timeout);
+ if (!time_left)
+ dev_err(&adap->dev, "virtio i2c backend timeout.\n");
+
+ count = virtio_i2c_complete_reqs(vq, reqs, msgs, count, !time_left);
+
+err_free:
+ kfree(reqs);
+ return count;
+}
+
+static void virtio_i2c_del_vqs(struct virtio_device *vdev)
+{
+ vdev->config->reset(vdev);
+ vdev->config->del_vqs(vdev);
+}
+
+static int virtio_i2c_setup_vqs(struct virtio_i2c *vi)
+{
+ struct virtio_device *vdev = vi->vdev;
+
+ vi->vq = virtio_find_single_vq(vdev, virtio_i2c_msg_done, "msg");
+ return PTR_ERR_OR_ZERO(vi->vq);
+}
+
+static u32 virtio_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+static struct i2c_algorithm virtio_algorithm = {
+ .master_xfer = virtio_i2c_xfer,
+ .functionality = virtio_i2c_func,
+};
+
+static const struct i2c_adapter_quirks virtio_i2c_quirks = {
+ .flags = I2C_AQ_NO_ZERO_LEN,
+};
+
+static int virtio_i2c_probe(struct virtio_device *vdev)
+{
+ struct device *pdev = vdev->dev.parent;
+ struct virtio_i2c *vi;
+ int ret;
+
+ vi = devm_kzalloc(&vdev->dev, sizeof(*vi), GFP_KERNEL);
+ if (!vi)
+ return -ENOMEM;
+
+ vdev->priv = vi;
+ vi->vdev = vdev;
+
+ init_completion(&vi->completion);
+
+ ret = virtio_i2c_setup_vqs(vi);
+ if (ret)
+ return ret;
+
+ vi->adap.owner = THIS_MODULE;
+ snprintf(vi->adap.name, sizeof(vi->adap.name),
+ "i2c_virtio at virtio bus %d", vdev->index);
+ vi->adap.algo = &virtio_algorithm;
+ vi->adap.quirks = &virtio_i2c_quirks;
+ vi->adap.dev.parent = &vdev->dev;
+ i2c_set_adapdata(&vi->adap, vi);
+
+ /*
+ * Setup ACPI node for controlled devices which will be probed through
+ * ACPI.
+ */
+ ACPI_COMPANION_SET(&vi->adap.dev, ACPI_COMPANION(pdev));
+
+ ret = i2c_add_adapter(&vi->adap);
+ if (ret)
+ virtio_i2c_del_vqs(vdev);
+
+ return ret;
+}
+
+static void virtio_i2c_remove(struct virtio_device *vdev)
+{
+ struct virtio_i2c *vi = vdev->priv;
+
+ i2c_del_adapter(&vi->adap);
+ virtio_i2c_del_vqs(vdev);
+}
+
+static struct virtio_device_id id_table[] = {
+ { VIRTIO_ID_I2C_ADAPTER, VIRTIO_DEV_ANY_ID },
+ {}
+};
+MODULE_DEVICE_TABLE(virtio, id_table);
+
+#ifdef CONFIG_PM_SLEEP
+static int virtio_i2c_freeze(struct virtio_device *vdev)
+{
+ virtio_i2c_del_vqs(vdev);
+ return 0;
+}
+
+static int virtio_i2c_restore(struct virtio_device *vdev)
+{
+ return virtio_i2c_setup_vqs(vdev->priv);
+}
+#endif
+
+static struct virtio_driver virtio_i2c_driver = {
+ .id_table = id_table,
+ .probe = virtio_i2c_probe,
+ .remove = virtio_i2c_remove,
+ .driver = {
+ .name = "i2c_virtio",
+ },
+#ifdef CONFIG_PM_SLEEP
+ .freeze = virtio_i2c_freeze,
+ .restore = virtio_i2c_restore,
+#endif
+};
+module_virtio_driver(virtio_i2c_driver);
+
+MODULE_AUTHOR("Jie Deng <[email protected]>");
+MODULE_AUTHOR("Conghui Chen <[email protected]>");
+MODULE_DESCRIPTION("Virtio i2c bus driver");
+MODULE_LICENSE("GPL");
diff --git a/include/uapi/linux/virtio_i2c.h b/include/uapi/linux/virtio_i2c.h
new file mode 100644
index 0000000..7c6a6fc
--- /dev/null
+++ b/include/uapi/linux/virtio_i2c.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later WITH Linux-syscall-note */
+/*
+ * Definitions for virtio I2C Adpter
+ *
+ * Copyright (c) 2021 Intel Corporation. All rights reserved.
+ */
+
+#ifndef _UAPI_LINUX_VIRTIO_I2C_H
+#define _UAPI_LINUX_VIRTIO_I2C_H
+
+#include <linux/const.h>
+#include <linux/types.h>
+
+/* The bit 0 of the @virtio_i2c_out_hdr.@flags, used to group the requests */
+#define VIRTIO_I2C_FLAGS_FAIL_NEXT _BITUL(0)
+
+/**
+ * struct virtio_i2c_out_hdr - the virtio I2C message OUT header
+ * @addr: the controlled device address
+ * @padding: used to pad to full dword
+ * @flags: used for feature extensibility
+ */
+struct virtio_i2c_out_hdr {
+ __le16 addr;
+ __le16 padding;
+ __le32 flags;
+};
+
+/**
+ * struct virtio_i2c_in_hdr - the virtio I2C message IN header
+ * @status: the processing result from the backend
+ */
+struct virtio_i2c_in_hdr {
+ __u8 status;
+};
+
+/* The final status written by the device */
+#define VIRTIO_I2C_MSG_OK 0
+#define VIRTIO_I2C_MSG_ERR 1
+
+#endif /* _UAPI_LINUX_VIRTIO_I2C_H */
diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h
index 70a8057a..99aa27b 100644
--- a/include/uapi/linux/virtio_ids.h
+++ b/include/uapi/linux/virtio_ids.h
@@ -55,6 +55,7 @@
#define VIRTIO_ID_FS 26 /* virtio filesystem */
#define VIRTIO_ID_PMEM 27 /* virtio pmem */
#define VIRTIO_ID_MAC80211_HWSIM 29 /* virtio mac80211-hwsim */
+#define VIRTIO_ID_I2C_ADAPTER 34 /* virtio i2c adapter */
#define VIRTIO_ID_BT 40 /* virtio bluetooth */

/*
--
2.7.4


2021-07-23 09:05:51

by Arnd Bergmann

[permalink] [raw]
Subject: Re: [PATCH v15] i2c: virtio: add a virtio i2c frontend driver

On Fri, Jul 23, 2021 at 7:44 AM Jie Deng <[email protected]> wrote:

> +
> + ret = virtio_i2c_setup_vqs(vi);
> + if (ret)
> + return ret;
> +
> + vi->adap.owner = THIS_MODULE;
> + snprintf(vi->adap.name, sizeof(vi->adap.name),
> + "i2c_virtio at virtio bus %d", vdev->index);
> + vi->adap.algo = &virtio_algorithm;
> + vi->adap.quirks = &virtio_i2c_quirks;
> + vi->adap.dev.parent = &vdev->dev;
> + i2c_set_adapdata(&vi->adap, vi);
> +
> + /*
> + * Setup ACPI node for controlled devices which will be probed through
> + * ACPI.
> + */
> + ACPI_COMPANION_SET(&vi->adap.dev, ACPI_COMPANION(pdev));

Since there is now a generic way for virtio drivers to link up with OF
device nodes, maybe this should be handled the same way in the
virtio core rather than the driver?

> index 70a8057a..99aa27b 100644
> --- a/include/uapi/linux/virtio_ids.h
> +++ b/include/uapi/linux/virtio_ids.h
> @@ -55,6 +55,7 @@
> #define VIRTIO_ID_FS 26 /* virtio filesystem */
> #define VIRTIO_ID_PMEM 27 /* virtio pmem */
> #define VIRTIO_ID_MAC80211_HWSIM 29 /* virtio mac80211-hwsim */
> +#define VIRTIO_ID_I2C_ADAPTER 34 /* virtio i2c adapter */
> #define VIRTIO_ID_BT 40 /* virtio bluetooth */

This will now conflict with Viresh's patch that adds all the other IDs.
Not sure if there is anything to be done about that.

Arnd

2021-07-26 04:00:36

by Viresh Kumar

[permalink] [raw]
Subject: Re: [PATCH v15] i2c: virtio: add a virtio i2c frontend driver

On 23-07-21, 11:03, Arnd Bergmann wrote:
> > index 70a8057a..99aa27b 100644
> > --- a/include/uapi/linux/virtio_ids.h
> > +++ b/include/uapi/linux/virtio_ids.h
> > @@ -55,6 +55,7 @@
> > #define VIRTIO_ID_FS 26 /* virtio filesystem */
> > #define VIRTIO_ID_PMEM 27 /* virtio pmem */
> > #define VIRTIO_ID_MAC80211_HWSIM 29 /* virtio mac80211-hwsim */
> > +#define VIRTIO_ID_I2C_ADAPTER 34 /* virtio i2c adapter */
> > #define VIRTIO_ID_BT 40 /* virtio bluetooth */
>
> This will now conflict with Viresh's patch that adds all the other IDs.
> Not sure if there is anything to be done about that.

An easier way of avoiding all such conflicts can be:

- Michael applies my first patch (which sync's the device id's from specs) for
5.14-rc4. Rest of the patches can go for 5.15.

- And then Wolfram applies this series over rc4 instead of rc1.

Or we can leave the conflict there for Linus to handle.

--
viresh

2021-07-27 02:17:38

by Jie Deng

[permalink] [raw]
Subject: Re: [PATCH v15] i2c: virtio: add a virtio i2c frontend driver


On 2021/7/23 17:03, Arnd Bergmann wrote:
> On Fri, Jul 23, 2021 at 7:44 AM Jie Deng <[email protected]> wrote:
>
>> +
>> + ret = virtio_i2c_setup_vqs(vi);
>> + if (ret)
>> + return ret;
>> +
>> + vi->adap.owner = THIS_MODULE;
>> + snprintf(vi->adap.name, sizeof(vi->adap.name),
>> + "i2c_virtio at virtio bus %d", vdev->index);
>> + vi->adap.algo = &virtio_algorithm;
>> + vi->adap.quirks = &virtio_i2c_quirks;
>> + vi->adap.dev.parent = &vdev->dev;
>> + i2c_set_adapdata(&vi->adap, vi);
>> +
>> + /*
>> + * Setup ACPI node for controlled devices which will be probed through
>> + * ACPI.
>> + */
>> + ACPI_COMPANION_SET(&vi->adap.dev, ACPI_COMPANION(pdev));
> Since there is now a generic way for virtio drivers to link up with OF
> device nodes, maybe this should be handled the same way in the
> virtio core rather than the driver?


I'm currently based on the I2C tree. Has that patch been already merged ?

Anyway, I think we can send an additional patch to remove this line once
that

"generic way" patch is merged.

Regards,

Jie



2021-07-27 04:25:37

by Viresh Kumar

[permalink] [raw]
Subject: Re: [PATCH v15] i2c: virtio: add a virtio i2c frontend driver

On 27-07-21, 10:15, Jie Deng wrote:
>
> On 2021/7/23 17:03, Arnd Bergmann wrote:
> > On Fri, Jul 23, 2021 at 7:44 AM Jie Deng <[email protected]> wrote:
> >
> > > +
> > > + ret = virtio_i2c_setup_vqs(vi);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + vi->adap.owner = THIS_MODULE;
> > > + snprintf(vi->adap.name, sizeof(vi->adap.name),
> > > + "i2c_virtio at virtio bus %d", vdev->index);
> > > + vi->adap.algo = &virtio_algorithm;
> > > + vi->adap.quirks = &virtio_i2c_quirks;
> > > + vi->adap.dev.parent = &vdev->dev;
> > > + i2c_set_adapdata(&vi->adap, vi);
> > > +
> > > + /*
> > > + * Setup ACPI node for controlled devices which will be probed through
> > > + * ACPI.
> > > + */
> > > + ACPI_COMPANION_SET(&vi->adap.dev, ACPI_COMPANION(pdev));
> > Since there is now a generic way for virtio drivers to link up with OF
> > device nodes, maybe this should be handled the same way in the
> > virtio core rather than the driver?
>
>
> I'm currently based on the I2C tree. Has that patch been already merged ?
>
> Anyway, I think we can send an additional patch to remove this line once
> that
>
> "generic way" patch is merged.

I agree, we need to get this merged and do stuff on top of it. We are
already on v15 :)

--
viresh

2021-07-28 09:37:27

by Wolfram Sang

[permalink] [raw]
Subject: Re: [PATCH v15] i2c: virtio: add a virtio i2c frontend driver


> > This will now conflict with Viresh's patch that adds all the other IDs.
> > Not sure if there is anything to be done about that.
>
> An easier way of avoiding all such conflicts can be:
>
> - Michael applies my first patch (which sync's the device id's from specs) for
> 5.14-rc4. Rest of the patches can go for 5.15.
>
> - And then Wolfram applies this series over rc4 instead of rc1.
>
> Or we can leave the conflict there for Linus to handle.

Or Michael creates an immutable branch for me to pull in. I am fine with
either approach. A bit in favor of the immutable branch.

Other than that, I am happy with the virtio driver itself and ready to
apply it once we decide how to handle the dependency.

Thank you everyone for the hard work and the patience!


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2021-08-17 20:24:20

by Wolfram Sang

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Subject: Re: [PATCH v15] i2c: virtio: add a virtio i2c frontend driver

On Fri, Jul 23, 2021 at 01:44:35PM +0800, Jie Deng wrote:
> Add an I2C bus driver for virtio para-virtualization.
>
> The controller can be emulated by the backend driver in
> any device model software by following the virtio protocol.
>
> The device specification can be found on
> https://lists.oasis-open.org/archives/virtio-comment/202101/msg00008.html.
>
> By following the specification, people may implement different
> backend drivers to emulate different controllers according to
> their needs.
>
> Co-developed-by: Conghui Chen <[email protected]>
> Signed-off-by: Conghui Chen <[email protected]>
> Signed-off-by: Jie Deng <[email protected]>
> Reviewed-by: Viresh Kumar <[email protected]>
> Tested-by: Viresh Kumar <[email protected]>
> Acked-by: Michael S. Tsirkin <[email protected]>

Okay, with rc6 being released, I won't wait for an immutable branch
anymore. I applied this now and we will see if there will be a merge
conflict. If so, it will be trivial to handle, I'd think. So:

Applied to for-next, thanks!


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2021-08-18 01:31:49

by Jie Deng

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Subject: Re: [PATCH v15] i2c: virtio: add a virtio i2c frontend driver


On 2021/8/18 4:22, Wolfram Sang wrote:
>
> Michael S. Tsirkin <[email protected]>
> Okay, with rc6 being released, I won't wait for an immutable branch
> anymore. I applied this now and we will see if there will be a merge
> conflict. If so, it will be trivial to handle, I'd think. So:
>
> Applied to for-next, thanks!


Thanks Wolfram!