[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Fri, Sep 25, 2015 at 04:53:47PM -0700, Rafael Antognolli wrote:
> On Tue, Sep 22, 2015 at 02:17:51PM +0200, Daniel Vetter wrote:
> > On Tue, Sep 22, 2015 at 03:00:54PM +0300, Ville Syrjälä wrote:
> > > On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> > > > This module is heavily based on i2c-dev. Once loaded, it provides one
> > > > dev node per DP AUX channel, named drm_aux-N.
> > > >
> > > > It's possible to know which connector owns this aux channel by looking
> > > > at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> > > > the connector device pointer was correctly set in the aux helper struct.
> > > >
> > > > Two main operations are provided on the registers: read and write. The
> > > > address of the register to be read or written is given using lseek.
> > > > Reading or writing does not update the offset of the file.
> > > >
> > > > Signed-off-by: Rafael Antognolli
> > > > ---
> > > > drivers/gpu/drm/Kconfig | 4 +
> > > > drivers/gpu/drm/Makefile | 1 +
> > > > drivers/gpu/drm/drm_aux-dev.c | 326
> > > > ++
> > > > 3 files changed, 331 insertions(+)
> > > > create mode 100644 drivers/gpu/drm/drm_aux-dev.c
> > > >
> > > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > > > index 1a0a8df..eae847c 100644
> > > > --- a/drivers/gpu/drm/Kconfig
> > > > +++ b/drivers/gpu/drm/Kconfig
> > > > @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> > > > bool
> > > > depends on DRM
> > > >
> > > > +config DRM_AUX_CHARDEV
> > > > + tristate "DRM DP AUX Interface"
> > > > + depends on DRM
> > > > +
> > > > config DRM_KMS_HELPER
> > > > tristate
> > > > depends on DRM
> > > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > > > index 45e7719..a1a94306 100644
> > > > --- a/drivers/gpu/drm/Makefile
> > > > +++ b/drivers/gpu/drm/Makefile
> > > > @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
> > > >
> > > > obj-$(CONFIG_DRM) += drm.o
> > > > obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> > > > +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
> > > > obj-$(CONFIG_DRM_TTM) += ttm/
> > > > obj-$(CONFIG_DRM_TDFX) += tdfx/
> > > > obj-$(CONFIG_DRM_R128) += r128/
> > > > diff --git a/drivers/gpu/drm/drm_aux-dev.c
> > > > b/drivers/gpu/drm/drm_aux-dev.c
> > > > new file mode 100644
> > > > index 000..fcc334a
> > > > --- /dev/null
> > > > +++ b/drivers/gpu/drm/drm_aux-dev.c
> > > > @@ -0,0 +1,326 @@
> > > > +/*
> > > > + * Copyright © 2015 Intel Corporation
> > > > + *
> > > > + * Permission is hereby granted, free of charge, to any person
> > > > obtaining a
> > > > + * copy of this software and associated documentation files (the
> > > > "Software"),
> > > > + * to deal in the Software without restriction, including without
> > > > limitation
> > > > + * the rights to use, copy, modify, merge, publish, distribute,
> > > > sublicense,
> > > > + * and/or sell copies of the Software, and to permit persons to whom
> > > > the
> > > > + * Software is furnished to do so, subject to the following conditions:
> > > > + *
> > > > + * The above copyright notice and this permission notice (including
> > > > the next
> > > > + * paragraph) shall be included in all copies or substantial portions
> > > > of the
> > > > + * Software.
> > > > + *
> > > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> > > > EXPRESS OR
> > > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> > > > MERCHANTABILITY,
> > > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
> > > > SHALL
> > > > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
> > > > OR OTHER
> > > > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> > > > ARISING
> > > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> > > > DEALINGS
> > > > + * IN THE SOFTWARE.
> > > > + *
> > > > + * Authors:
> > > > + *Rafael Antognolli
> > > > + *
> > > > + */
> > > > +
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +
> > > > +struct drm_aux_dev {
> > > > + struct list_head list;
> > > > + unsigned index;
> > > > + struct drm_dp_aux *aux;
> > > > + struct device *dev;
> > > > +};
> > > > +
> > > > +#define DRM_AUX_MINORS 256
> > > > +static int drm_aux_dev_count = 0;
> > > > +static LIST_HEAD(drm_aux_dev_list);
> > > > +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> > > > +
> > > > +static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
> > > > +{
> > > > + struct drm_aux_dev *aux_dev;
> > > > +
> > > > + spin_lock(&drm_aux_dev_list_lock);
> > > > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> > > > + if (aux_dev->index == index)
> > > > +
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 22, 2015 at 02:17:51PM +0200, Daniel Vetter wrote:
> On Tue, Sep 22, 2015 at 03:00:54PM +0300, Ville Syrjälä wrote:
> > On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> > > This module is heavily based on i2c-dev. Once loaded, it provides one
> > > dev node per DP AUX channel, named drm_aux-N.
> > >
> > > It's possible to know which connector owns this aux channel by looking
> > > at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> > > the connector device pointer was correctly set in the aux helper struct.
> > >
> > > Two main operations are provided on the registers: read and write. The
> > > address of the register to be read or written is given using lseek.
> > > Reading or writing does not update the offset of the file.
> > >
> > > Signed-off-by: Rafael Antognolli
> > > ---
> > > drivers/gpu/drm/Kconfig | 4 +
> > > drivers/gpu/drm/Makefile | 1 +
> > > drivers/gpu/drm/drm_aux-dev.c | 326
> > > ++
> > > 3 files changed, 331 insertions(+)
> > > create mode 100644 drivers/gpu/drm/drm_aux-dev.c
> > >
> > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > > index 1a0a8df..eae847c 100644
> > > --- a/drivers/gpu/drm/Kconfig
> > > +++ b/drivers/gpu/drm/Kconfig
> > > @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> > > bool
> > > depends on DRM
> > >
> > > +config DRM_AUX_CHARDEV
> > > + tristate "DRM DP AUX Interface"
> > > + depends on DRM
> > > +
> > > config DRM_KMS_HELPER
> > > tristate
> > > depends on DRM
> > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > > index 45e7719..a1a94306 100644
> > > --- a/drivers/gpu/drm/Makefile
> > > +++ b/drivers/gpu/drm/Makefile
> > > @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
> > >
> > > obj-$(CONFIG_DRM)+= drm.o
> > > obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> > > +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
> > > obj-$(CONFIG_DRM_TTM)+= ttm/
> > > obj-$(CONFIG_DRM_TDFX) += tdfx/
> > > obj-$(CONFIG_DRM_R128) += r128/
> > > diff --git a/drivers/gpu/drm/drm_aux-dev.c b/drivers/gpu/drm/drm_aux-dev.c
> > > new file mode 100644
> > > index 000..fcc334a
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/drm_aux-dev.c
> > > @@ -0,0 +1,326 @@
> > > +/*
> > > + * Copyright © 2015 Intel Corporation
> > > + *
> > > + * Permission is hereby granted, free of charge, to any person obtaining
> > > a
> > > + * copy of this software and associated documentation files (the
> > > "Software"),
> > > + * to deal in the Software without restriction, including without
> > > limitation
> > > + * the rights to use, copy, modify, merge, publish, distribute,
> > > sublicense,
> > > + * and/or sell copies of the Software, and to permit persons to whom the
> > > + * Software is furnished to do so, subject to the following conditions:
> > > + *
> > > + * The above copyright notice and this permission notice (including the
> > > next
> > > + * paragraph) shall be included in all copies or substantial portions of
> > > the
> > > + * Software.
> > > + *
> > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> > > EXPRESS OR
> > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> > > MERCHANTABILITY,
> > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
> > > SHALL
> > > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> > > OTHER
> > > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> > > ARISING
> > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> > > DEALINGS
> > > + * IN THE SOFTWARE.
> > > + *
> > > + * Authors:
> > > + *Rafael Antognolli
> > > + *
> > > + */
> > > +
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +
> > > +struct drm_aux_dev {
> > > + struct list_head list;
> > > + unsigned index;
> > > + struct drm_dp_aux *aux;
> > > + struct device *dev;
> > > +};
> > > +
> > > +#define DRM_AUX_MINORS 256
> > > +static int drm_aux_dev_count = 0;
> > > +static LIST_HEAD(drm_aux_dev_list);
> > > +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> > > +
> > > +static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
> > > +{
> > > + struct drm_aux_dev *aux_dev;
> > > +
> > > + spin_lock(&drm_aux_dev_list_lock);
> > > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> > > + if (aux_dev->index == index)
> > > + goto found;
> > > + }
> > > +
> > > + aux_dev = NULL;
> > > +found:
> > > + spin_unlock(&drm_aux_dev_list_lock);
> > > + return aux_dev;
> > > +}
> > > +
> > > +static struct drm_aux_dev *drm_aux_dev_get_by_aux(struct drm_dp_aux *aux)
> > > +{
> > > + struct drm_aux_dev *aux_dev;
> > > +
> > > + spin_lock(&drm_aux_dev_list_lock);
> > > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> >
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 22, 2015 at 10:48:06AM -0700, Rafael Antognolli wrote:
> On Tue, Sep 22, 2015 at 10:59:51AM +0200, Daniel Vetter wrote:
> > On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> > > This module is heavily based on i2c-dev. Once loaded, it provides one
> > > dev node per DP AUX channel, named drm_aux-N.
> > >
> > > It's possible to know which connector owns this aux channel by looking
> > > at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> > > the connector device pointer was correctly set in the aux helper struct.
> > >
> > > Two main operations are provided on the registers: read and write. The
> > > address of the register to be read or written is given using lseek.
> > > Reading or writing does not update the offset of the file.
> >
> > I think not updating the read position is very surprising. Would it be
> > hard to fix that?
>
> No, not hard at all. But I assume then I should update the write
> position too, right?
>
> BTW, i2c-dev doesn't update either of them, but I'm not sure why.
I think there's just no standard definition of what an offset would mean
for an i2c device. For standard eeproms it would work as one would expect,
but generally it's device specific.
>
> > >
> > > Signed-off-by: Rafael Antognolli
> > > ---
> > > drivers/gpu/drm/Kconfig | 4 +
> > > drivers/gpu/drm/Makefile | 1 +
> > > drivers/gpu/drm/drm_aux-dev.c | 326
> > > ++
> > > 3 files changed, 331 insertions(+)
> > > create mode 100644 drivers/gpu/drm/drm_aux-dev.c
> > >
> > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > > index 1a0a8df..eae847c 100644
> > > --- a/drivers/gpu/drm/Kconfig
> > > +++ b/drivers/gpu/drm/Kconfig
> > > @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> > > bool
> > > depends on DRM
> > >
> > > +config DRM_AUX_CHARDEV
> > > + tristate "DRM DP AUX Interface"
> > > + depends on DRM
> > > +
> > > config DRM_KMS_HELPER
> > > tristate
> > > depends on DRM
> > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > > index 45e7719..a1a94306 100644
> > > --- a/drivers/gpu/drm/Makefile
> > > +++ b/drivers/gpu/drm/Makefile
> > > @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
> > >
> > > obj-$(CONFIG_DRM)+= drm.o
> > > obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> > > +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
> > > obj-$(CONFIG_DRM_TTM)+= ttm/
> > > obj-$(CONFIG_DRM_TDFX) += tdfx/
> > > obj-$(CONFIG_DRM_R128) += r128/
> > > diff --git a/drivers/gpu/drm/drm_aux-dev.c b/drivers/gpu/drm/drm_aux-dev.c
> > > new file mode 100644
> > > index 000..fcc334a
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/drm_aux-dev.c
> > > @@ -0,0 +1,326 @@
> > > +/*
> > > + * Copyright © 2015 Intel Corporation
> > > + *
> > > + * Permission is hereby granted, free of charge, to any person obtaining
> > > a
> > > + * copy of this software and associated documentation files (the
> > > "Software"),
> > > + * to deal in the Software without restriction, including without
> > > limitation
> > > + * the rights to use, copy, modify, merge, publish, distribute,
> > > sublicense,
> > > + * and/or sell copies of the Software, and to permit persons to whom the
> > > + * Software is furnished to do so, subject to the following conditions:
> > > + *
> > > + * The above copyright notice and this permission notice (including the
> > > next
> > > + * paragraph) shall be included in all copies or substantial portions of
> > > the
> > > + * Software.
> > > + *
> > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> > > EXPRESS OR
> > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> > > MERCHANTABILITY,
> > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
> > > SHALL
> > > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> > > OTHER
> > > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> > > ARISING
> > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> > > DEALINGS
> > > + * IN THE SOFTWARE.
> > > + *
> > > + * Authors:
> > > + *Rafael Antognolli
> > > + *
> > > + */
> > > +
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +
> > > +struct drm_aux_dev {
> > > + struct list_head list;
> > > + unsigned index;
> > > + struct drm_dp_aux *aux;
> > > + struct device *dev;
> > > +};
> > > +
> > > +#define DRM_AUX_MINORS 256
> > > +static int drm_aux_dev_count = 0;
> > > +static LIST_HEAD(drm_aux_dev_list);
> > > +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> > > +
> > > +static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
> > > +{
> > > + struct drm_aux_dev *aux_dev;
> > > +
> > > + spin_lock(&drm_aux_dev_list_lock);
> > > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> > > +
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 22, 2015 at 02:59:24PM +0200, Daniel Vetter wrote:
> On Tue, Sep 22, 2015 at 03:35:13PM +0300, Ville Syrjälä wrote:
> > On Tue, Sep 22, 2015 at 02:17:51PM +0200, Daniel Vetter wrote:
> > > On Tue, Sep 22, 2015 at 03:00:54PM +0300, Ville Syrjälä wrote:
> > > > On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> > > > > This module is heavily based on i2c-dev. Once loaded, it provides one
> > > > > dev node per DP AUX channel, named drm_aux-N.
> > > > >
> > > > > It's possible to know which connector owns this aux channel by looking
> > > > > at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> > > > > the connector device pointer was correctly set in the aux helper
> > > > > struct.
> > > > >
> > > > > Two main operations are provided on the registers: read and write. The
> > > > > address of the register to be read or written is given using lseek.
> > > > > Reading or writing does not update the offset of the file.
> > > > >
> > > > > Signed-off-by: Rafael Antognolli
> > > > > ---
> > > > > drivers/gpu/drm/Kconfig | 4 +
> > > > > drivers/gpu/drm/Makefile | 1 +
> > > > > drivers/gpu/drm/drm_aux-dev.c | 326
> > > > > ++
> > > > > 3 files changed, 331 insertions(+)
> > > > > create mode 100644 drivers/gpu/drm/drm_aux-dev.c
> > > > >
> > > > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > > > > index 1a0a8df..eae847c 100644
> > > > > --- a/drivers/gpu/drm/Kconfig
> > > > > +++ b/drivers/gpu/drm/Kconfig
> > > > > @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> > > > > bool
> > > > > depends on DRM
> > > > >
> > > > > +config DRM_AUX_CHARDEV
> > > > > + tristate "DRM DP AUX Interface"
> > > > > + depends on DRM
> > > > > +
> > > > > config DRM_KMS_HELPER
> > > > > tristate
> > > > > depends on DRM
> > > > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > > > > index 45e7719..a1a94306 100644
> > > > > --- a/drivers/gpu/drm/Makefile
> > > > > +++ b/drivers/gpu/drm/Makefile
> > > > > @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
> > > > >
> > > > > obj-$(CONFIG_DRM)+= drm.o
> > > > > obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> > > > > +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
> > > > > obj-$(CONFIG_DRM_TTM)+= ttm/
> > > > > obj-$(CONFIG_DRM_TDFX) += tdfx/
> > > > > obj-$(CONFIG_DRM_R128) += r128/
> > > > > diff --git a/drivers/gpu/drm/drm_aux-dev.c
> > > > > b/drivers/gpu/drm/drm_aux-dev.c
> > > > > new file mode 100644
> > > > > index 000..fcc334a
> > > > > --- /dev/null
> > > > > +++ b/drivers/gpu/drm/drm_aux-dev.c
> > > > > @@ -0,0 +1,326 @@
> > > > > +/*
> > > > > + * Copyright © 2015 Intel Corporation
> > > > > + *
> > > > > + * Permission is hereby granted, free of charge, to any person
> > > > > obtaining a
> > > > > + * copy of this software and associated documentation files (the
> > > > > "Software"),
> > > > > + * to deal in the Software without restriction, including without
> > > > > limitation
> > > > > + * the rights to use, copy, modify, merge, publish, distribute,
> > > > > sublicense,
> > > > > + * and/or sell copies of the Software, and to permit persons to whom
> > > > > the
> > > > > + * Software is furnished to do so, subject to the following
> > > > > conditions:
> > > > > + *
> > > > > + * The above copyright notice and this permission notice (including
> > > > > the next
> > > > > + * paragraph) shall be included in all copies or substantial
> > > > > portions of the
> > > > > + * Software.
> > > > > + *
> > > > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> > > > > EXPRESS OR
> > > > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> > > > > MERCHANTABILITY,
> > > > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
> > > > > EVENT SHALL
> > > > > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
> > > > > OR OTHER
> > > > > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> > > > > ARISING
> > > > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> > > > > OTHER DEALINGS
> > > > > + * IN THE SOFTWARE.
> > > > > + *
> > > > > + * Authors:
> > > > > + *Rafael Antognolli
> > > > > + *
> > > > > + */
> > > > > +
> > > > > +#include
> > > > > +#include
> > > > > +#include
> > > > > +#include
> > > > > +#include
> > > > > +#include
> > > > > +#include
> > > > > +#include
> > > > > +#include
> > > > > +
> > > > > +struct drm_aux_dev {
> > > > > + struct list_head list;
> > > > > + unsigned index;
> > > > > + struct drm_dp_aux *aux;
> > > > > + struct device *dev;
> > > > > +};
> > > > > +
> > > > > +#define DRM_AUX_MINORS 256
> > > > > +static int drm_aux_dev_count = 0;
> > > > > +static LIST_HEAD(drm_aux_dev_list);
> > > > > +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> > > > > +
> > > > > +
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 22, 2015 at 02:17:51PM +0200, Daniel Vetter wrote:
> On Tue, Sep 22, 2015 at 03:00:54PM +0300, Ville Syrjälä wrote:
> > On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> > > This module is heavily based on i2c-dev. Once loaded, it provides one
> > > dev node per DP AUX channel, named drm_aux-N.
> > >
> > > It's possible to know which connector owns this aux channel by looking
> > > at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> > > the connector device pointer was correctly set in the aux helper struct.
> > >
> > > Two main operations are provided on the registers: read and write. The
> > > address of the register to be read or written is given using lseek.
> > > Reading or writing does not update the offset of the file.
> > >
> > > Signed-off-by: Rafael Antognolli
> > > ---
> > > drivers/gpu/drm/Kconfig | 4 +
> > > drivers/gpu/drm/Makefile | 1 +
> > > drivers/gpu/drm/drm_aux-dev.c | 326
> > > ++
> > > 3 files changed, 331 insertions(+)
> > > create mode 100644 drivers/gpu/drm/drm_aux-dev.c
> > >
> > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > > index 1a0a8df..eae847c 100644
> > > --- a/drivers/gpu/drm/Kconfig
> > > +++ b/drivers/gpu/drm/Kconfig
> > > @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> > > bool
> > > depends on DRM
> > >
> > > +config DRM_AUX_CHARDEV
> > > + tristate "DRM DP AUX Interface"
> > > + depends on DRM
> > > +
> > > config DRM_KMS_HELPER
> > > tristate
> > > depends on DRM
> > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > > index 45e7719..a1a94306 100644
> > > --- a/drivers/gpu/drm/Makefile
> > > +++ b/drivers/gpu/drm/Makefile
> > > @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
> > >
> > > obj-$(CONFIG_DRM)+= drm.o
> > > obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> > > +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
> > > obj-$(CONFIG_DRM_TTM)+= ttm/
> > > obj-$(CONFIG_DRM_TDFX) += tdfx/
> > > obj-$(CONFIG_DRM_R128) += r128/
> > > diff --git a/drivers/gpu/drm/drm_aux-dev.c b/drivers/gpu/drm/drm_aux-dev.c
> > > new file mode 100644
> > > index 000..fcc334a
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/drm_aux-dev.c
> > > @@ -0,0 +1,326 @@
> > > +/*
> > > + * Copyright © 2015 Intel Corporation
> > > + *
> > > + * Permission is hereby granted, free of charge, to any person obtaining
> > > a
> > > + * copy of this software and associated documentation files (the
> > > "Software"),
> > > + * to deal in the Software without restriction, including without
> > > limitation
> > > + * the rights to use, copy, modify, merge, publish, distribute,
> > > sublicense,
> > > + * and/or sell copies of the Software, and to permit persons to whom the
> > > + * Software is furnished to do so, subject to the following conditions:
> > > + *
> > > + * The above copyright notice and this permission notice (including the
> > > next
> > > + * paragraph) shall be included in all copies or substantial portions of
> > > the
> > > + * Software.
> > > + *
> > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> > > EXPRESS OR
> > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> > > MERCHANTABILITY,
> > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
> > > SHALL
> > > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> > > OTHER
> > > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> > > ARISING
> > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> > > DEALINGS
> > > + * IN THE SOFTWARE.
> > > + *
> > > + * Authors:
> > > + *Rafael Antognolli
> > > + *
> > > + */
> > > +
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +
> > > +struct drm_aux_dev {
> > > + struct list_head list;
> > > + unsigned index;
> > > + struct drm_dp_aux *aux;
> > > + struct device *dev;
> > > +};
> > > +
> > > +#define DRM_AUX_MINORS 256
> > > +static int drm_aux_dev_count = 0;
> > > +static LIST_HEAD(drm_aux_dev_list);
> > > +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> > > +
> > > +static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
> > > +{
> > > + struct drm_aux_dev *aux_dev;
> > > +
> > > + spin_lock(&drm_aux_dev_list_lock);
> > > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> > > + if (aux_dev->index == index)
> > > + goto found;
> > > + }
> > > +
> > > + aux_dev = NULL;
> > > +found:
> > > + spin_unlock(&drm_aux_dev_list_lock);
> > > + return aux_dev;
> > > +}
> > > +
> > > +static struct drm_aux_dev *drm_aux_dev_get_by_aux(struct drm_dp_aux *aux)
> > > +{
> > > + struct drm_aux_dev *aux_dev;
> > > +
> > > + spin_lock(&drm_aux_dev_list_lock);
> > > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> >
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 22, 2015 at 04:25:17PM +0300, Ville Syrjälä wrote:
> On Tue, Sep 22, 2015 at 02:59:24PM +0200, Daniel Vetter wrote:
> > On Tue, Sep 22, 2015 at 03:35:13PM +0300, Ville Syrjälä wrote:
> > > On Tue, Sep 22, 2015 at 02:17:51PM +0200, Daniel Vetter wrote:
> > > > Iirc short reads are ok in all cases, so we could even punt the
> > > > restarting
> > > > to userspace by just doing short reads/writes (like sockets do).
> > >
> > > Yeah, short writes due to -EFAULT sound more dangerous than short reads.
> > > But I'm not sure there's any point in allowing short reads either in
> > > this case, so just returning the error upfront if access_ok() complains
> > > seems like a sane option to me.
> >
> > access_ok _only_ does static checks (on x86 it only checks that it's a
> > userspace address). Which means any kind of real faults will only happen
> > later on in the actual copy_to/from_user. I'd say we can go meh if that
> > happens - it's guaranteed to be userspace doing something silly since we
> > don't need to hold any of the mm locks ;-)
>
> Hmm, true. So I guess on -EFAULT we should:
>
> if (copy_{to,from}_user())
> return num_bytes_processed ? num_bytes_processed : -EFAULT;
>
> Sound reasonable?
Yeah that's what I'd go with.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> This module is heavily based on i2c-dev. Once loaded, it provides one
> dev node per DP AUX channel, named drm_aux-N.
>
> It's possible to know which connector owns this aux channel by looking
> at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> the connector device pointer was correctly set in the aux helper struct.
>
> Two main operations are provided on the registers: read and write. The
> address of the register to be read or written is given using lseek.
> Reading or writing does not update the offset of the file.
>
> Signed-off-by: Rafael Antognolli
> ---
> drivers/gpu/drm/Kconfig | 4 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/drm_aux-dev.c | 326
> ++
> 3 files changed, 331 insertions(+)
> create mode 100644 drivers/gpu/drm/drm_aux-dev.c
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 1a0a8df..eae847c 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> bool
> depends on DRM
>
> +config DRM_AUX_CHARDEV
> + tristate "DRM DP AUX Interface"
> + depends on DRM
> +
> config DRM_KMS_HELPER
> tristate
> depends on DRM
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 45e7719..a1a94306 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
>
> obj-$(CONFIG_DRM)+= drm.o
> obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
> obj-$(CONFIG_DRM_TTM)+= ttm/
> obj-$(CONFIG_DRM_TDFX) += tdfx/
> obj-$(CONFIG_DRM_R128) += r128/
> diff --git a/drivers/gpu/drm/drm_aux-dev.c b/drivers/gpu/drm/drm_aux-dev.c
> new file mode 100644
> index 000..fcc334a
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_aux-dev.c
> @@ -0,0 +1,326 @@
> +/*
> + * Copyright © 2015 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + *Rafael Antognolli
> + *
> + */
> +
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +
> +struct drm_aux_dev {
> + struct list_head list;
> + unsigned index;
> + struct drm_dp_aux *aux;
> + struct device *dev;
> +};
> +
> +#define DRM_AUX_MINORS 256
> +static int drm_aux_dev_count = 0;
> +static LIST_HEAD(drm_aux_dev_list);
> +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> +
> +static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
> +{
> + struct drm_aux_dev *aux_dev;
> +
> + spin_lock(&drm_aux_dev_list_lock);
> + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> + if (aux_dev->index == index)
> + goto found;
> + }
> +
> + aux_dev = NULL;
> +found:
> + spin_unlock(&drm_aux_dev_list_lock);
> + return aux_dev;
> +}
> +
> +static struct drm_aux_dev *drm_aux_dev_get_by_aux(struct drm_dp_aux *aux)
> +{
> + struct drm_aux_dev *aux_dev;
> +
> + spin_lock(&drm_aux_dev_list_lock);
> + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> + if (aux_dev->aux == aux)
> + goto found;
> + }
> +
> + aux_dev = NULL;
> +found:
> + spin_unlock(&drm_aux_dev_list_lock);
> + return aux_dev;
> +}
> +
> +static struct drm_aux_dev *get_free_drm_aux_dev(struct drm_dp_aux *aux)
> +{
> + struct drm_aux_dev *aux_dev;
> + int index;
> +
> + spin_lock(&drm_aux_dev_list_lock);
> + index = drm_aux_dev_count;
> + spin_unlock(&drm_aux_dev_list_lock);
> + if (index >= DRM_AUX_MINORS) {
> + printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
> +index);
> +
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 22, 2015 at 03:35:13PM +0300, Ville Syrjälä wrote:
> On Tue, Sep 22, 2015 at 02:17:51PM +0200, Daniel Vetter wrote:
> > On Tue, Sep 22, 2015 at 03:00:54PM +0300, Ville Syrjälä wrote:
> > > On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> > > > This module is heavily based on i2c-dev. Once loaded, it provides one
> > > > dev node per DP AUX channel, named drm_aux-N.
> > > >
> > > > It's possible to know which connector owns this aux channel by looking
> > > > at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> > > > the connector device pointer was correctly set in the aux helper struct.
> > > >
> > > > Two main operations are provided on the registers: read and write. The
> > > > address of the register to be read or written is given using lseek.
> > > > Reading or writing does not update the offset of the file.
> > > >
> > > > Signed-off-by: Rafael Antognolli
> > > > ---
> > > > drivers/gpu/drm/Kconfig | 4 +
> > > > drivers/gpu/drm/Makefile | 1 +
> > > > drivers/gpu/drm/drm_aux-dev.c | 326
> > > > ++
> > > > 3 files changed, 331 insertions(+)
> > > > create mode 100644 drivers/gpu/drm/drm_aux-dev.c
> > > >
> > > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > > > index 1a0a8df..eae847c 100644
> > > > --- a/drivers/gpu/drm/Kconfig
> > > > +++ b/drivers/gpu/drm/Kconfig
> > > > @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> > > > bool
> > > > depends on DRM
> > > >
> > > > +config DRM_AUX_CHARDEV
> > > > + tristate "DRM DP AUX Interface"
> > > > + depends on DRM
> > > > +
> > > > config DRM_KMS_HELPER
> > > > tristate
> > > > depends on DRM
> > > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > > > index 45e7719..a1a94306 100644
> > > > --- a/drivers/gpu/drm/Makefile
> > > > +++ b/drivers/gpu/drm/Makefile
> > > > @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
> > > >
> > > > obj-$(CONFIG_DRM) += drm.o
> > > > obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> > > > +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
> > > > obj-$(CONFIG_DRM_TTM) += ttm/
> > > > obj-$(CONFIG_DRM_TDFX) += tdfx/
> > > > obj-$(CONFIG_DRM_R128) += r128/
> > > > diff --git a/drivers/gpu/drm/drm_aux-dev.c
> > > > b/drivers/gpu/drm/drm_aux-dev.c
> > > > new file mode 100644
> > > > index 000..fcc334a
> > > > --- /dev/null
> > > > +++ b/drivers/gpu/drm/drm_aux-dev.c
> > > > @@ -0,0 +1,326 @@
> > > > +/*
> > > > + * Copyright © 2015 Intel Corporation
> > > > + *
> > > > + * Permission is hereby granted, free of charge, to any person
> > > > obtaining a
> > > > + * copy of this software and associated documentation files (the
> > > > "Software"),
> > > > + * to deal in the Software without restriction, including without
> > > > limitation
> > > > + * the rights to use, copy, modify, merge, publish, distribute,
> > > > sublicense,
> > > > + * and/or sell copies of the Software, and to permit persons to whom
> > > > the
> > > > + * Software is furnished to do so, subject to the following conditions:
> > > > + *
> > > > + * The above copyright notice and this permission notice (including
> > > > the next
> > > > + * paragraph) shall be included in all copies or substantial portions
> > > > of the
> > > > + * Software.
> > > > + *
> > > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> > > > EXPRESS OR
> > > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> > > > MERCHANTABILITY,
> > > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
> > > > SHALL
> > > > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
> > > > OR OTHER
> > > > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> > > > ARISING
> > > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> > > > DEALINGS
> > > > + * IN THE SOFTWARE.
> > > > + *
> > > > + * Authors:
> > > > + *Rafael Antognolli
> > > > + *
> > > > + */
> > > > +
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +#include
> > > > +
> > > > +struct drm_aux_dev {
> > > > + struct list_head list;
> > > > + unsigned index;
> > > > + struct drm_dp_aux *aux;
> > > > + struct device *dev;
> > > > +};
> > > > +
> > > > +#define DRM_AUX_MINORS 256
> > > > +static int drm_aux_dev_count = 0;
> > > > +static LIST_HEAD(drm_aux_dev_list);
> > > > +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> > > > +
> > > > +static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
> > > > +{
> > > > + struct drm_aux_dev *aux_dev;
> > > > +
> > > > + spin_lock(&drm_aux_dev_list_lock);
> > > > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> > > > + if (aux_dev->index == index)
> > > > +
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 22, 2015 at 03:00:54PM +0300, Ville Syrjälä wrote:
> On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> > This module is heavily based on i2c-dev. Once loaded, it provides one
> > dev node per DP AUX channel, named drm_aux-N.
> >
> > It's possible to know which connector owns this aux channel by looking
> > at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> > the connector device pointer was correctly set in the aux helper struct.
> >
> > Two main operations are provided on the registers: read and write. The
> > address of the register to be read or written is given using lseek.
> > Reading or writing does not update the offset of the file.
> >
> > Signed-off-by: Rafael Antognolli
> > ---
> > drivers/gpu/drm/Kconfig | 4 +
> > drivers/gpu/drm/Makefile | 1 +
> > drivers/gpu/drm/drm_aux-dev.c | 326
> > ++
> > 3 files changed, 331 insertions(+)
> > create mode 100644 drivers/gpu/drm/drm_aux-dev.c
> >
> > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > index 1a0a8df..eae847c 100644
> > --- a/drivers/gpu/drm/Kconfig
> > +++ b/drivers/gpu/drm/Kconfig
> > @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> > bool
> > depends on DRM
> >
> > +config DRM_AUX_CHARDEV
> > + tristate "DRM DP AUX Interface"
> > + depends on DRM
> > +
> > config DRM_KMS_HELPER
> > tristate
> > depends on DRM
> > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > index 45e7719..a1a94306 100644
> > --- a/drivers/gpu/drm/Makefile
> > +++ b/drivers/gpu/drm/Makefile
> > @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
> >
> > obj-$(CONFIG_DRM) += drm.o
> > obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> > +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
> > obj-$(CONFIG_DRM_TTM) += ttm/
> > obj-$(CONFIG_DRM_TDFX) += tdfx/
> > obj-$(CONFIG_DRM_R128) += r128/
> > diff --git a/drivers/gpu/drm/drm_aux-dev.c b/drivers/gpu/drm/drm_aux-dev.c
> > new file mode 100644
> > index 000..fcc334a
> > --- /dev/null
> > +++ b/drivers/gpu/drm/drm_aux-dev.c
> > @@ -0,0 +1,326 @@
> > +/*
> > + * Copyright © 2015 Intel Corporation
> > + *
> > + * Permission is hereby granted, free of charge, to any person obtaining a
> > + * copy of this software and associated documentation files (the
> > "Software"),
> > + * to deal in the Software without restriction, including without
> > limitation
> > + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> > + * and/or sell copies of the Software, and to permit persons to whom the
> > + * Software is furnished to do so, subject to the following conditions:
> > + *
> > + * The above copyright notice and this permission notice (including the
> > next
> > + * paragraph) shall be included in all copies or substantial portions of
> > the
> > + * Software.
> > + *
> > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
> > OR
> > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> > OTHER
> > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> > DEALINGS
> > + * IN THE SOFTWARE.
> > + *
> > + * Authors:
> > + *Rafael Antognolli
> > + *
> > + */
> > +
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +
> > +struct drm_aux_dev {
> > + struct list_head list;
> > + unsigned index;
> > + struct drm_dp_aux *aux;
> > + struct device *dev;
> > +};
> > +
> > +#define DRM_AUX_MINORS 256
> > +static int drm_aux_dev_count = 0;
> > +static LIST_HEAD(drm_aux_dev_list);
> > +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> > +
> > +static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
> > +{
> > + struct drm_aux_dev *aux_dev;
> > +
> > + spin_lock(&drm_aux_dev_list_lock);
> > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> > + if (aux_dev->index == index)
> > + goto found;
> > + }
> > +
> > + aux_dev = NULL;
> > +found:
> > + spin_unlock(&drm_aux_dev_list_lock);
> > + return aux_dev;
> > +}
> > +
> > +static struct drm_aux_dev *drm_aux_dev_get_by_aux(struct drm_dp_aux *aux)
> > +{
> > + struct drm_aux_dev *aux_dev;
> > +
> > + spin_lock(&drm_aux_dev_list_lock);
> > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> > + if (aux_dev->aux == aux)
> > + goto found;
> > + }
> > +
> > + aux_dev = NULL;
> > +found:
> > + spin_unlock(&drm_aux_dev_list_lock);
> > + return aux_dev;
> > +}
> > +
> > +static struct drm_aux_dev *get_free_drm_aux_dev(struct drm_dp_aux *aux)
> > +{
> > + struct drm_aux_dev
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> This module is heavily based on i2c-dev. Once loaded, it provides one
> dev node per DP AUX channel, named drm_aux-N.
>
> It's possible to know which connector owns this aux channel by looking
> at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> the connector device pointer was correctly set in the aux helper struct.
>
> Two main operations are provided on the registers: read and write. The
> address of the register to be read or written is given using lseek.
> Reading or writing does not update the offset of the file.
>
> Signed-off-by: Rafael Antognolli
> ---
> drivers/gpu/drm/Kconfig | 4 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/drm_aux-dev.c | 326
> ++
> 3 files changed, 331 insertions(+)
> create mode 100644 drivers/gpu/drm/drm_aux-dev.c
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 1a0a8df..eae847c 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> bool
> depends on DRM
>
> +config DRM_AUX_CHARDEV
> + tristate "DRM DP AUX Interface"
Imo just make this a boolean, will simplify things a lot. Also if you
implement the drm_dp_aux_register_devnode you need to add static inline
stubs for register/unregister functions so that it all works out if this
option is disabled. See for example how the recent changes to the drm fb
helpers are done.
> + depends on DRM
> +
> config DRM_KMS_HELPER
> tristate
> depends on DRM
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 45e7719..a1a94306 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
>
> obj-$(CONFIG_DRM)+= drm.o
> obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
I'd call the file drm_dp_aux_dev.o, drm_dp_aux for consistency in prefixes
and mixing - and _ in filenames looks strange to me ;-)
-Daniel
> obj-$(CONFIG_DRM_TTM)+= ttm/
> obj-$(CONFIG_DRM_TDFX) += tdfx/
> obj-$(CONFIG_DRM_R128) += r128/
> diff --git a/drivers/gpu/drm/drm_aux-dev.c b/drivers/gpu/drm/drm_aux-dev.c
> new file mode 100644
> index 000..fcc334a
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_aux-dev.c
> @@ -0,0 +1,326 @@
> +/*
> + * Copyright © 2015 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + *Rafael Antognolli
> + *
> + */
> +
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +
> +struct drm_aux_dev {
> + struct list_head list;
> + unsigned index;
> + struct drm_dp_aux *aux;
> + struct device *dev;
> +};
> +
> +#define DRM_AUX_MINORS 256
> +static int drm_aux_dev_count = 0;
> +static LIST_HEAD(drm_aux_dev_list);
> +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> +
> +static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
> +{
> + struct drm_aux_dev *aux_dev;
> +
> + spin_lock(&drm_aux_dev_list_lock);
> + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> + if (aux_dev->index == index)
> + goto found;
> + }
> +
> + aux_dev = NULL;
> +found:
> + spin_unlock(&drm_aux_dev_list_lock);
> + return aux_dev;
> +}
> +
> +static struct drm_aux_dev *drm_aux_dev_get_by_aux(struct drm_dp_aux *aux)
> +{
> + struct drm_aux_dev *aux_dev;
> +
> + spin_lock(&drm_aux_dev_list_lock);
> + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> + if (aux_dev->aux == aux)
> + goto found;
> + }
> +
> + aux_dev = NULL;
> +found:
> + spin_unlock(&drm_aux_dev_list_loc
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> This module is heavily based on i2c-dev. Once loaded, it provides one
> dev node per DP AUX channel, named drm_aux-N.
>
> It's possible to know which connector owns this aux channel by looking
> at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> the connector device pointer was correctly set in the aux helper struct.
>
> Two main operations are provided on the registers: read and write. The
> address of the register to be read or written is given using lseek.
> Reading or writing does not update the offset of the file.
I think not updating the read position is very surprising. Would it be
hard to fix that?
-Daniel
>
> Signed-off-by: Rafael Antognolli
> ---
> drivers/gpu/drm/Kconfig | 4 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/drm_aux-dev.c | 326
> ++
> 3 files changed, 331 insertions(+)
> create mode 100644 drivers/gpu/drm/drm_aux-dev.c
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 1a0a8df..eae847c 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> bool
> depends on DRM
>
> +config DRM_AUX_CHARDEV
> + tristate "DRM DP AUX Interface"
> + depends on DRM
> +
> config DRM_KMS_HELPER
> tristate
> depends on DRM
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 45e7719..a1a94306 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
>
> obj-$(CONFIG_DRM)+= drm.o
> obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
> obj-$(CONFIG_DRM_TTM)+= ttm/
> obj-$(CONFIG_DRM_TDFX) += tdfx/
> obj-$(CONFIG_DRM_R128) += r128/
> diff --git a/drivers/gpu/drm/drm_aux-dev.c b/drivers/gpu/drm/drm_aux-dev.c
> new file mode 100644
> index 000..fcc334a
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_aux-dev.c
> @@ -0,0 +1,326 @@
> +/*
> + * Copyright © 2015 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + *Rafael Antognolli
> + *
> + */
> +
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +
> +struct drm_aux_dev {
> + struct list_head list;
> + unsigned index;
> + struct drm_dp_aux *aux;
> + struct device *dev;
> +};
> +
> +#define DRM_AUX_MINORS 256
> +static int drm_aux_dev_count = 0;
> +static LIST_HEAD(drm_aux_dev_list);
> +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> +
> +static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
> +{
> + struct drm_aux_dev *aux_dev;
> +
> + spin_lock(&drm_aux_dev_list_lock);
> + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> + if (aux_dev->index == index)
> + goto found;
> + }
> +
> + aux_dev = NULL;
> +found:
> + spin_unlock(&drm_aux_dev_list_lock);
> + return aux_dev;
> +}
> +
> +static struct drm_aux_dev *drm_aux_dev_get_by_aux(struct drm_dp_aux *aux)
> +{
> + struct drm_aux_dev *aux_dev;
> +
> + spin_lock(&drm_aux_dev_list_lock);
> + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> + if (aux_dev->aux == aux)
> + goto found;
> + }
> +
> + aux_dev = NULL;
> +found:
> + spin_unlock(&drm_aux_dev_list_lock);
> + return aux_dev;
> +}
> +
> +static struct drm_aux_dev *get_free_drm_aux_dev(struct drm_dp_aux *aux)
> +{
> + struct drm_aux_dev *aux_dev;
> + int index;
> +
> + spin_lock(&drm_aux_dev_list_lock);
> + index = drm_aux_dev_count;
> + spin_unlock(&drm_aux_dev_list_lock);
> + if (index >= DRM_AUX_MINORS) {
> +
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
On Tue, Sep 22, 2015 at 10:59:51AM +0200, Daniel Vetter wrote:
> On Tue, Sep 15, 2015 at 04:55:04PM -0700, Rafael Antognolli wrote:
> > This module is heavily based on i2c-dev. Once loaded, it provides one
> > dev node per DP AUX channel, named drm_aux-N.
> >
> > It's possible to know which connector owns this aux channel by looking
> > at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
> > the connector device pointer was correctly set in the aux helper struct.
> >
> > Two main operations are provided on the registers: read and write. The
> > address of the register to be read or written is given using lseek.
> > Reading or writing does not update the offset of the file.
>
> I think not updating the read position is very surprising. Would it be
> hard to fix that?
No, not hard at all. But I assume then I should update the write
position too, right?
BTW, i2c-dev doesn't update either of them, but I'm not sure why.
> >
> > Signed-off-by: Rafael Antognolli
> > ---
> > drivers/gpu/drm/Kconfig | 4 +
> > drivers/gpu/drm/Makefile | 1 +
> > drivers/gpu/drm/drm_aux-dev.c | 326
> > ++
> > 3 files changed, 331 insertions(+)
> > create mode 100644 drivers/gpu/drm/drm_aux-dev.c
> >
> > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > index 1a0a8df..eae847c 100644
> > --- a/drivers/gpu/drm/Kconfig
> > +++ b/drivers/gpu/drm/Kconfig
> > @@ -25,6 +25,10 @@ config DRM_MIPI_DSI
> > bool
> > depends on DRM
> >
> > +config DRM_AUX_CHARDEV
> > + tristate "DRM DP AUX Interface"
> > + depends on DRM
> > +
> > config DRM_KMS_HELPER
> > tristate
> > depends on DRM
> > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > index 45e7719..a1a94306 100644
> > --- a/drivers/gpu/drm/Makefile
> > +++ b/drivers/gpu/drm/Makefile
> > @@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
> >
> > obj-$(CONFIG_DRM) += drm.o
> > obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
> > +obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
> > obj-$(CONFIG_DRM_TTM) += ttm/
> > obj-$(CONFIG_DRM_TDFX) += tdfx/
> > obj-$(CONFIG_DRM_R128) += r128/
> > diff --git a/drivers/gpu/drm/drm_aux-dev.c b/drivers/gpu/drm/drm_aux-dev.c
> > new file mode 100644
> > index 000..fcc334a
> > --- /dev/null
> > +++ b/drivers/gpu/drm/drm_aux-dev.c
> > @@ -0,0 +1,326 @@
> > +/*
> > + * Copyright © 2015 Intel Corporation
> > + *
> > + * Permission is hereby granted, free of charge, to any person obtaining a
> > + * copy of this software and associated documentation files (the
> > "Software"),
> > + * to deal in the Software without restriction, including without
> > limitation
> > + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> > + * and/or sell copies of the Software, and to permit persons to whom the
> > + * Software is furnished to do so, subject to the following conditions:
> > + *
> > + * The above copyright notice and this permission notice (including the
> > next
> > + * paragraph) shall be included in all copies or substantial portions of
> > the
> > + * Software.
> > + *
> > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
> > OR
> > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> > OTHER
> > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> > DEALINGS
> > + * IN THE SOFTWARE.
> > + *
> > + * Authors:
> > + *Rafael Antognolli
> > + *
> > + */
> > +
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +
> > +struct drm_aux_dev {
> > + struct list_head list;
> > + unsigned index;
> > + struct drm_dp_aux *aux;
> > + struct device *dev;
> > +};
> > +
> > +#define DRM_AUX_MINORS 256
> > +static int drm_aux_dev_count = 0;
> > +static LIST_HEAD(drm_aux_dev_list);
> > +static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
> > +
> > +static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
> > +{
> > + struct drm_aux_dev *aux_dev;
> > +
> > + spin_lock(&drm_aux_dev_list_lock);
> > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> > + if (aux_dev->index == index)
> > + goto found;
> > + }
> > +
> > + aux_dev = NULL;
> > +found:
> > + spin_unlock(&drm_aux_dev_list_lock);
> > + return aux_dev;
> > +}
> > +
> > +static struct drm_aux_dev *drm_aux_dev_get_by_aux(struct drm_dp_aux *aux)
> > +{
> > + struct drm_aux_dev *aux_dev;
> > +
> > + spin_lock(&drm_aux_dev_list_lock);
> > + list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
> > + if (aux_dev->aux == aux)
> > + goto fou
[PATCH RFC v2 3/3] drm/dp: Add a drm_aux-dev module for reading/writing dpcd registers.
This module is heavily based on i2c-dev. Once loaded, it provides one
dev node per DP AUX channel, named drm_aux-N.
It's possible to know which connector owns this aux channel by looking
at the respective sysfs /sys/class/drm_aux-dev/drm_aux-N/connector, if
the connector device pointer was correctly set in the aux helper struct.
Two main operations are provided on the registers: read and write. The
address of the register to be read or written is given using lseek.
Reading or writing does not update the offset of the file.
Signed-off-by: Rafael Antognolli
---
drivers/gpu/drm/Kconfig | 4 +
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/drm_aux-dev.c | 326 ++
3 files changed, 331 insertions(+)
create mode 100644 drivers/gpu/drm/drm_aux-dev.c
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 1a0a8df..eae847c 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -25,6 +25,10 @@ config DRM_MIPI_DSI
bool
depends on DRM
+config DRM_AUX_CHARDEV
+ tristate "DRM DP AUX Interface"
+ depends on DRM
+
config DRM_KMS_HELPER
tristate
depends on DRM
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 45e7719..a1a94306 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -32,6 +32,7 @@ CFLAGS_drm_trace_points.o := -I$(src)
obj-$(CONFIG_DRM) += drm.o
obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
+obj-$(CONFIG_DRM_AUX_CHARDEV) += drm_aux-dev.o
obj-$(CONFIG_DRM_TTM) += ttm/
obj-$(CONFIG_DRM_TDFX) += tdfx/
obj-$(CONFIG_DRM_R128) += r128/
diff --git a/drivers/gpu/drm/drm_aux-dev.c b/drivers/gpu/drm/drm_aux-dev.c
new file mode 100644
index 000..fcc334a
--- /dev/null
+++ b/drivers/gpu/drm/drm_aux-dev.c
@@ -0,0 +1,326 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *Rafael Antognolli
+ *
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+struct drm_aux_dev {
+ struct list_head list;
+ unsigned index;
+ struct drm_dp_aux *aux;
+ struct device *dev;
+};
+
+#define DRM_AUX_MINORS 256
+static int drm_aux_dev_count = 0;
+static LIST_HEAD(drm_aux_dev_list);
+static DEFINE_SPINLOCK(drm_aux_dev_list_lock);
+
+static struct drm_aux_dev *drm_aux_dev_get_by_minor(unsigned index)
+{
+ struct drm_aux_dev *aux_dev;
+
+ spin_lock(&drm_aux_dev_list_lock);
+ list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
+ if (aux_dev->index == index)
+ goto found;
+ }
+
+ aux_dev = NULL;
+found:
+ spin_unlock(&drm_aux_dev_list_lock);
+ return aux_dev;
+}
+
+static struct drm_aux_dev *drm_aux_dev_get_by_aux(struct drm_dp_aux *aux)
+{
+ struct drm_aux_dev *aux_dev;
+
+ spin_lock(&drm_aux_dev_list_lock);
+ list_for_each_entry(aux_dev, &drm_aux_dev_list, list) {
+ if (aux_dev->aux == aux)
+ goto found;
+ }
+
+ aux_dev = NULL;
+found:
+ spin_unlock(&drm_aux_dev_list_lock);
+ return aux_dev;
+}
+
+static struct drm_aux_dev *get_free_drm_aux_dev(struct drm_dp_aux *aux)
+{
+ struct drm_aux_dev *aux_dev;
+ int index;
+
+ spin_lock(&drm_aux_dev_list_lock);
+ index = drm_aux_dev_count;
+ spin_unlock(&drm_aux_dev_list_lock);
+ if (index >= DRM_AUX_MINORS) {
+ printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
+ index);
+ return ERR_PTR(-ENODEV);
+ }
+
+ aux_dev = kzalloc(sizeof(*aux_dev), GFP_KERNEL);
+ if (!aux_dev)
+ return ERR_PTR(-ENOMEM);
+ aux_dev->aux = aux;
+ aux_dev->index = index;
+
+ spin_lock(&drm_aux_dev_list_lock);
+ drm_aux_dev_count++;
+ list_
