Re: [PATCH v4 4/4] bus: mhi: clients: Add userspace client interface driver
Hi Greg,
On 7/28/20 11:17 PM, Greg KH wrote:
On Tue, Jul 28, 2020 at 08:46:35PM -0700, Hemant Kumar wrote:
This MHI client driver allows userspace clients to transfer
raw data between MHI device and host using standard file operations.
Device file node is created with format
/dev/mhi__
Currently it supports LOOPBACK channel.
Signed-off-by: Hemant Kumar
---
drivers/bus/mhi/Kconfig | 6 +
drivers/bus/mhi/Makefile | 1 +
drivers/bus/mhi/clients/Kconfig | 15 +
drivers/bus/mhi/clients/Makefile | 3 +
drivers/bus/mhi/clients/uci.c| 690 +++
5 files changed, 715 insertions(+)
create mode 100644 drivers/bus/mhi/clients/Kconfig
create mode 100644 drivers/bus/mhi/clients/Makefile
create mode 100644 drivers/bus/mhi/clients/uci.c
diff --git a/drivers/bus/mhi/Kconfig b/drivers/bus/mhi/Kconfig
index 6a217ff..927c392 100644
--- a/drivers/bus/mhi/Kconfig
+++ b/drivers/bus/mhi/Kconfig
@@ -20,3 +20,9 @@ config MHI_BUS_DEBUG
Enable debugfs support for use with the MHI transport. Allows
reading and/or modifying some values within the MHI controller
for debug and test purposes.
+
+if MHI_BUS
+
+source "drivers/bus/mhi/clients/Kconfig"
+
+endif
diff --git a/drivers/bus/mhi/Makefile b/drivers/bus/mhi/Makefile
index 19e6443..48f6028 100644
--- a/drivers/bus/mhi/Makefile
+++ b/drivers/bus/mhi/Makefile
@@ -1,2 +1,3 @@
# core layer
obj-y += core/
+obj-y += clients/
diff --git a/drivers/bus/mhi/clients/Kconfig b/drivers/bus/mhi/clients/Kconfig
new file mode 100644
index 000..37aaf51
--- /dev/null
+++ b/drivers/bus/mhi/clients/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "MHI clients support"
+
+config MHI_UCI
+ tristate "MHI UCI"
+ depends on MHI_BUS
+ help
+MHI based userspace client interface driver is used for transferring
+raw data between host and device using standard file operations from
+userspace. Open, read, write, and close operations are supported
+by this driver. Please check mhi_uci_match_table for all supported
+channels that are exposed to userspace.
+
+endmenu
diff --git a/drivers/bus/mhi/clients/Makefile b/drivers/bus/mhi/clients/Makefile
new file mode 100644
index 000..cd34282
--- /dev/null
+++ b/drivers/bus/mhi/clients/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_MHI_UCI) += uci.o
diff --git a/drivers/bus/mhi/clients/uci.c b/drivers/bus/mhi/clients/uci.c
new file mode 100644
index 000..3ddf017
--- /dev/null
+++ b/drivers/bus/mhi/clients/uci.c
@@ -0,0 +1,690 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.*/
+
+#include
+#include
+#include
+#include
+#include
+
+#define DEVICE_NAME "mhi"
+#define MHI_UCI_DRIVER_NAME "mhi_uci"
+#define MAX_UCI_DEVICES (64)
+
+/**
+ * struct uci_chan - MHI channel for a uci device
+ * @wq: wait queue for reader/writer
+ * @lock: spin lock
+ * @pending: list of rx buffers userspace is waiting to read
+ * @cur_buf: current buffer userspace is reading
+ * @rx_size: size of the current rx buffer userspace is reading
+ */
+struct uci_chan {
+ wait_queue_head_t wq;
+
+ /* protects pending and cur_buf members */
+ spinlock_t lock;
+
+ struct list_head pending;
+ struct uci_buf *cur_buf;
+ size_t rx_size;
+};
+
+/**
+ * struct uci_buf - uci buffer
+ * @data: data buffer
+ * @len: length of data buffer
+ * @node: list node of the uci buffer
+ */
+struct uci_buf {
+ void *data;
+ size_t len;
+ struct list_head node;
+};
+
+/**
+ * struct mhi_uci_drv - MHI uci driver
+ * @head: list head of a uci device nodes
+ * @lock: mutex lock
+ * @class: current buffer userspace is reading
+ * @major: major number for uci driver
+ * @devt: dev_t object to hold major and minor info
+ */
+struct mhi_uci_drv {
+ struct list_head head;
+
+ /* protects mhi_uci_drv struct members */
+ struct mutex lock;
+
+ struct class *class;
+ int major;
+ dev_t devt;
+};
So this is just a single static structure for some "global" variables
for the driver? Why make it a structure at all?
And why have a local list of all devices, doesn't the driver core give
that to you already? You shouldn't need that if you are doing things
properly...Done, will get rid of this struct and use static global variable for
major number, class and idr
+
+/**
+ * struct uci_dev - MHI uci device
+ * @node: uci device node
+ * @devt: dev_t object to hold major and minor info
+ * @dev: uci device object
+ * @mhi_dev: associated mhi device object
+ * @chan: MHI channel name
+ * @lock: mutex lock
+ * @ul_chan: uplink uci channel object
+ * @dl_chan: downlink uci channel object
+ * @mtu: max tx buffer length
+ * @actual_mtu: maximum size of incoming buffer
+ * @ref_count: uci_dev reference count
+ * @enabled: uci device node
Re: [PATCH v4 4/4] bus: mhi: clients: Add userspace client interface driver
On Tue, Jul 28, 2020 at 08:46:35PM -0700, Hemant Kumar wrote:
> This MHI client driver allows userspace clients to transfer
> raw data between MHI device and host using standard file operations.
> Device file node is created with format
>
> /dev/mhi__
>
> Currently it supports LOOPBACK channel.
>
> Signed-off-by: Hemant Kumar
> ---
> drivers/bus/mhi/Kconfig | 6 +
> drivers/bus/mhi/Makefile | 1 +
> drivers/bus/mhi/clients/Kconfig | 15 +
> drivers/bus/mhi/clients/Makefile | 3 +
> drivers/bus/mhi/clients/uci.c| 690
> +++
> 5 files changed, 715 insertions(+)
> create mode 100644 drivers/bus/mhi/clients/Kconfig
> create mode 100644 drivers/bus/mhi/clients/Makefile
> create mode 100644 drivers/bus/mhi/clients/uci.c
>
> diff --git a/drivers/bus/mhi/Kconfig b/drivers/bus/mhi/Kconfig
> index 6a217ff..927c392 100644
> --- a/drivers/bus/mhi/Kconfig
> +++ b/drivers/bus/mhi/Kconfig
> @@ -20,3 +20,9 @@ config MHI_BUS_DEBUG
>Enable debugfs support for use with the MHI transport. Allows
>reading and/or modifying some values within the MHI controller
>for debug and test purposes.
> +
> +if MHI_BUS
> +
> +source "drivers/bus/mhi/clients/Kconfig"
> +
> +endif
> diff --git a/drivers/bus/mhi/Makefile b/drivers/bus/mhi/Makefile
> index 19e6443..48f6028 100644
> --- a/drivers/bus/mhi/Makefile
> +++ b/drivers/bus/mhi/Makefile
> @@ -1,2 +1,3 @@
> # core layer
> obj-y += core/
> +obj-y += clients/
> diff --git a/drivers/bus/mhi/clients/Kconfig b/drivers/bus/mhi/clients/Kconfig
> new file mode 100644
> index 000..37aaf51
> --- /dev/null
> +++ b/drivers/bus/mhi/clients/Kconfig
> @@ -0,0 +1,15 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +menu "MHI clients support"
> +
> +config MHI_UCI
> + tristate "MHI UCI"
> + depends on MHI_BUS
> + help
> + MHI based userspace client interface driver is used for transferring
> + raw data between host and device using standard file operations from
> + userspace. Open, read, write, and close operations are supported
> + by this driver. Please check mhi_uci_match_table for all supported
> + channels that are exposed to userspace.
> +
> +endmenu
> diff --git a/drivers/bus/mhi/clients/Makefile
> b/drivers/bus/mhi/clients/Makefile
> new file mode 100644
> index 000..cd34282
> --- /dev/null
> +++ b/drivers/bus/mhi/clients/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +obj-$(CONFIG_MHI_UCI) += uci.o
> diff --git a/drivers/bus/mhi/clients/uci.c b/drivers/bus/mhi/clients/uci.c
> new file mode 100644
> index 000..3ddf017
> --- /dev/null
> +++ b/drivers/bus/mhi/clients/uci.c
> @@ -0,0 +1,690 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/* Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.*/
> +
> +#include
> +#include
> +#include
> +#include
> +#include
> +
> +#define DEVICE_NAME "mhi"
> +#define MHI_UCI_DRIVER_NAME "mhi_uci"
> +#define MAX_UCI_DEVICES (64)
> +
> +/**
> + * struct uci_chan - MHI channel for a uci device
> + * @wq: wait queue for reader/writer
> + * @lock: spin lock
> + * @pending: list of rx buffers userspace is waiting to read
> + * @cur_buf: current buffer userspace is reading
> + * @rx_size: size of the current rx buffer userspace is reading
> + */
> +struct uci_chan {
> + wait_queue_head_t wq;
> +
> + /* protects pending and cur_buf members */
> + spinlock_t lock;
> +
> + struct list_head pending;
> + struct uci_buf *cur_buf;
> + size_t rx_size;
> +};
> +
> +/**
> + * struct uci_buf - uci buffer
> + * @data: data buffer
> + * @len: length of data buffer
> + * @node: list node of the uci buffer
> + */
> +struct uci_buf {
> + void *data;
> + size_t len;
> + struct list_head node;
> +};
> +
> +/**
> + * struct mhi_uci_drv - MHI uci driver
> + * @head: list head of a uci device nodes
> + * @lock: mutex lock
> + * @class: current buffer userspace is reading
> + * @major: major number for uci driver
> + * @devt: dev_t object to hold major and minor info
> + */
> +struct mhi_uci_drv {
> + struct list_head head;
> +
> + /* protects mhi_uci_drv struct members */
> + struct mutex lock;
> +
> + struct class *class;
> + int major;
> + dev_t devt;
> +};
So this is just a single static structure for some "global" variables
for the driver? Why make it a structure at all?
And why have a local list of all devices, doesn't the driver core give
that to you already? You shouldn't need that if you are doing things
properly...
> +
> +/**
> + * struct uci_dev - MHI uci device
> + * @node: uci device node
> + * @devt: dev_t object to hold major and minor info
> + * @dev: uci device object
> + * @mhi_dev: associated mhi device object
> + * @chan: MHI channel name
> + * @lock: mutex lock
> + * @ul_chan: uplink uci channel object
> + * @dl_chan: downlink uci channel object
> + * @mtu: max tx buffer length
> + * @actual_mtu:
[PATCH v4 4/4] bus: mhi: clients: Add userspace client interface driver
This MHI client driver allows userspace clients to transfer
raw data between MHI device and host using standard file operations.
Device file node is created with format
/dev/mhi__
Currently it supports LOOPBACK channel.
Signed-off-by: Hemant Kumar
---
drivers/bus/mhi/Kconfig | 6 +
drivers/bus/mhi/Makefile | 1 +
drivers/bus/mhi/clients/Kconfig | 15 +
drivers/bus/mhi/clients/Makefile | 3 +
drivers/bus/mhi/clients/uci.c| 690 +++
5 files changed, 715 insertions(+)
create mode 100644 drivers/bus/mhi/clients/Kconfig
create mode 100644 drivers/bus/mhi/clients/Makefile
create mode 100644 drivers/bus/mhi/clients/uci.c
diff --git a/drivers/bus/mhi/Kconfig b/drivers/bus/mhi/Kconfig
index 6a217ff..927c392 100644
--- a/drivers/bus/mhi/Kconfig
+++ b/drivers/bus/mhi/Kconfig
@@ -20,3 +20,9 @@ config MHI_BUS_DEBUG
Enable debugfs support for use with the MHI transport. Allows
reading and/or modifying some values within the MHI controller
for debug and test purposes.
+
+if MHI_BUS
+
+source "drivers/bus/mhi/clients/Kconfig"
+
+endif
diff --git a/drivers/bus/mhi/Makefile b/drivers/bus/mhi/Makefile
index 19e6443..48f6028 100644
--- a/drivers/bus/mhi/Makefile
+++ b/drivers/bus/mhi/Makefile
@@ -1,2 +1,3 @@
# core layer
obj-y += core/
+obj-y += clients/
diff --git a/drivers/bus/mhi/clients/Kconfig b/drivers/bus/mhi/clients/Kconfig
new file mode 100644
index 000..37aaf51
--- /dev/null
+++ b/drivers/bus/mhi/clients/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "MHI clients support"
+
+config MHI_UCI
+ tristate "MHI UCI"
+ depends on MHI_BUS
+ help
+MHI based userspace client interface driver is used for transferring
+raw data between host and device using standard file operations from
+userspace. Open, read, write, and close operations are supported
+by this driver. Please check mhi_uci_match_table for all supported
+channels that are exposed to userspace.
+
+endmenu
diff --git a/drivers/bus/mhi/clients/Makefile b/drivers/bus/mhi/clients/Makefile
new file mode 100644
index 000..cd34282
--- /dev/null
+++ b/drivers/bus/mhi/clients/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_MHI_UCI) += uci.o
diff --git a/drivers/bus/mhi/clients/uci.c b/drivers/bus/mhi/clients/uci.c
new file mode 100644
index 000..3ddf017
--- /dev/null
+++ b/drivers/bus/mhi/clients/uci.c
@@ -0,0 +1,690 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.*/
+
+#include
+#include
+#include
+#include
+#include
+
+#define DEVICE_NAME "mhi"
+#define MHI_UCI_DRIVER_NAME "mhi_uci"
+#define MAX_UCI_DEVICES (64)
+
+/**
+ * struct uci_chan - MHI channel for a uci device
+ * @wq: wait queue for reader/writer
+ * @lock: spin lock
+ * @pending: list of rx buffers userspace is waiting to read
+ * @cur_buf: current buffer userspace is reading
+ * @rx_size: size of the current rx buffer userspace is reading
+ */
+struct uci_chan {
+ wait_queue_head_t wq;
+
+ /* protects pending and cur_buf members */
+ spinlock_t lock;
+
+ struct list_head pending;
+ struct uci_buf *cur_buf;
+ size_t rx_size;
+};
+
+/**
+ * struct uci_buf - uci buffer
+ * @data: data buffer
+ * @len: length of data buffer
+ * @node: list node of the uci buffer
+ */
+struct uci_buf {
+ void *data;
+ size_t len;
+ struct list_head node;
+};
+
+/**
+ * struct mhi_uci_drv - MHI uci driver
+ * @head: list head of a uci device nodes
+ * @lock: mutex lock
+ * @class: current buffer userspace is reading
+ * @major: major number for uci driver
+ * @devt: dev_t object to hold major and minor info
+ */
+struct mhi_uci_drv {
+ struct list_head head;
+
+ /* protects mhi_uci_drv struct members */
+ struct mutex lock;
+
+ struct class *class;
+ int major;
+ dev_t devt;
+};
+
+/**
+ * struct uci_dev - MHI uci device
+ * @node: uci device node
+ * @devt: dev_t object to hold major and minor info
+ * @dev: uci device object
+ * @mhi_dev: associated mhi device object
+ * @chan: MHI channel name
+ * @lock: mutex lock
+ * @ul_chan: uplink uci channel object
+ * @dl_chan: downlink uci channel object
+ * @mtu: max tx buffer length
+ * @actual_mtu: maximum size of incoming buffer
+ * @ref_count: uci_dev reference count
+ * @enabled: uci device node accessibility
+ */
+struct uci_dev {
+ struct list_head node;
+ dev_t devt;
+ struct device *dev;
+ struct mhi_device *mhi_dev;
+ const char *chan;
+
+ /* protects uci_dev struct members */
+ struct mutex lock;
+
+ struct uci_chan ul_chan;
+ struct uci_chan dl_chan;
+ size_t mtu;
+ size_t actual_mtu;
+ int ref_count;
+ bool enabled;
+};
+
+static DECLARE_BITMAP(uci_minors, MAX_UCI_DEVICES);
+static struct mhi_uci_drv
