[PATCH] drm/bridge: ite-it6263: Add basic resume support

[PATCH] drm/bridge: ite-it6263: Add basic resume support

[Biju]

From: Biju Das <biju.das.jz@bp.renesas.com>

RZ/G3L SMARC EVK has a single-link LVDS connected to an ITE IT6263 chip.
On the RZ/G3L SMARC EVK using PSCI, s2ram powers down the ITE IT6263 chip.
Add a minimal system resume callback to restore the bridge after s2ram.
The it6263_resume() callback re-establishes the LVDS I2C address and
reconfigures the LVDS output. Wire it into a dev_pm_ops struct using
SET_SYSTEM_SLEEP_PM_OPS with no suspend handler, and attach it to the
driver via pm_sleep_ptr().

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
 drivers/gpu/drm/bridge/ite-it6263.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ite-it6263.c b/drivers/gpu/drm/bridge/ite-it6263.c
index 4f3ebb7af4d4..9727ebef48e8 100644
--- a/drivers/gpu/drm/bridge/ite-it6263.c
+++ b/drivers/gpu/drm/bridge/ite-it6263.c
@@ -906,6 +906,24 @@ static int it6263_probe(struct i2c_client *client)
 	return devm_drm_bridge_add(dev, &it->bridge);
 }
 
+static int it6263_resume(struct device *dev)
+{
+	struct it6263 *it = dev_get_drvdata(dev);
+	int ret;
+
+	ret = it6263_lvds_set_i2c_addr(it);
+	if (ret)
+		return ret;
+
+	it6263_lvds_config(it);
+
+	return 0;
+}
+
+static const struct dev_pm_ops it6263_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(NULL, it6263_resume)
+};
+
 static const struct of_device_id it6263_of_match[] = {
 	{ .compatible = "ite,it6263", },
 	{ }
@@ -922,6 +940,7 @@ static struct i2c_driver it6263_driver = {
 	.probe = it6263_probe,
 	.driver = {
 		.name = "it6263",
+		.pm = pm_sleep_ptr(&it6263_pm_ops),
 		.of_match_table = it6263_of_match,
 	},
 	.id_table = it6263_i2c_ids,
-- 
2.43.0

Re: [PATCH] drm/bridge: ite-it6263: Add basic resume support

[Liu Ying]

Hi Biju,

On Wed, Apr 15, 2026 at 12:39:52PM +0100, Biju wrote:
> [You don't often get email from biju.das.au@gmail.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
> 
> From: Biju Das <biju.das.jz@bp.renesas.com>
> 
> RZ/G3L SMARC EVK has a single-link LVDS connected to an ITE IT6263 chip.
> On the RZ/G3L SMARC EVK using PSCI, s2ram powers down the ITE IT6263 chip.
> Add a minimal system resume callback to restore the bridge after s2ram.
> The it6263_resume() callback re-establishes the LVDS I2C address and
> reconfigures the LVDS output. Wire it into a dev_pm_ops struct using
> SET_SYSTEM_SLEEP_PM_OPS with no suspend handler, and attach it to the
> driver via pm_sleep_ptr().

drm_mode_config_helper_{suspend,resume} called by a display controller
driver's system PM callbacks should be able to kind of provide system
PM for this bridge through this bridge driver's atomic_{disable,enable}
callbacks.  To do this, regulator enablement, GPIO reset control and
bridge initialization need to be moved from probe to atomic_enable,
plus regulator disablement needs to be added to atomic_disable.
The bridge initialization includes it6263_lvds_set_i2c_addr(),
it6263_lvds_config() and it6263_hdmi_config().  Make sense?

> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> ---
>  drivers/gpu/drm/bridge/ite-it6263.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/ite-it6263.c b/drivers/gpu/drm/bridge/ite-it6263.c
> index 4f3ebb7af4d4..9727ebef48e8 100644
> --- a/drivers/gpu/drm/bridge/ite-it6263.c
> +++ b/drivers/gpu/drm/bridge/ite-it6263.c
> @@ -906,6 +906,24 @@ static int it6263_probe(struct i2c_client *client)
>         return devm_drm_bridge_add(dev, &it->bridge);
>  }
> 
> +static int it6263_resume(struct device *dev)
> +{
> +       struct it6263 *it = dev_get_drvdata(dev);
> +       int ret;
> +
> +       ret = it6263_lvds_set_i2c_addr(it);
> +       if (ret)
> +               return ret;
> +
> +       it6263_lvds_config(it);
> +
> +       return 0;
> +}
> +
> +static const struct dev_pm_ops it6263_pm_ops = {
> +       SET_SYSTEM_SLEEP_PM_OPS(NULL, it6263_resume)
> +};
> +
>  static const struct of_device_id it6263_of_match[] = {
>         { .compatible = "ite,it6263", },
>         { }
> @@ -922,6 +940,7 @@ static struct i2c_driver it6263_driver = {
>         .probe = it6263_probe,
>         .driver = {
>                 .name = "it6263",
> +               .pm = pm_sleep_ptr(&it6263_pm_ops),
>                 .of_match_table = it6263_of_match,
>         },
>         .id_table = it6263_i2c_ids,
> --
> 2.43.0
> 

-- 
Regards,
Liu Ying

RE: [PATCH] drm/bridge: ite-it6263: Add basic resume support

[Biju Das]

Hi Liu Ying,

Thanks for the feedback.

> -----Original Message-----
> From: Liu Ying <victor.liu@nxp.com>
> Sent: 16 April 2026 06:53
> Subject: Re: [PATCH] drm/bridge: ite-it6263: Add basic resume support
> 
> Hi Biju,
> 
> On Wed, Apr 15, 2026 at 12:39:52PM +0100, Biju wrote:
> > [You don't often get email from biju.das.au@gmail.com. Learn why this
> > is important at https://aka.ms/LearnAboutSenderIdentification ]
> >
> > From: Biju Das <biju.das.jz@bp.renesas.com>
> >
> > RZ/G3L SMARC EVK has a single-link LVDS connected to an ITE IT6263 chip.
> > On the RZ/G3L SMARC EVK using PSCI, s2ram powers down the ITE IT6263 chip.
> > Add a minimal system resume callback to restore the bridge after s2ram.
> > The it6263_resume() callback re-establishes the LVDS I2C address and
> > reconfigures the LVDS output. Wire it into a dev_pm_ops struct using
> > SET_SYSTEM_SLEEP_PM_OPS with no suspend handler, and attach it to the
> > driver via pm_sleep_ptr().
> 
> drm_mode_config_helper_{suspend,resume} called by a display controller driver's system PM callbacks
> should be able to kind of provide system PM for this bridge through this bridge driver's
> atomic_{disable,enable} callbacks.  To do this, regulator enablement, GPIO reset control and bridge
> initialization need to be moved from probe to atomic_enable, plus regulator disablement needs to be
> added to atomic_disable.
> The bridge initialization includes it6263_lvds_set_i2c_addr(),
> it6263_lvds_config() and it6263_hdmi_config().  Make sense?

OK, will send v2 with these changes.


Cheers,
Biju

> 
> >
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > ---
> >  drivers/gpu/drm/bridge/ite-it6263.c | 19 +++++++++++++++++++
> >  1 file changed, 19 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/bridge/ite-it6263.c
> > b/drivers/gpu/drm/bridge/ite-it6263.c
> > index 4f3ebb7af4d4..9727ebef48e8 100644
> > --- a/drivers/gpu/drm/bridge/ite-it6263.c
> > +++ b/drivers/gpu/drm/bridge/ite-it6263.c
> > @@ -906,6 +906,24 @@ static int it6263_probe(struct i2c_client *client)
> >         return devm_drm_bridge_add(dev, &it->bridge);  }
> >
> > +static int it6263_resume(struct device *dev) {
> > +       struct it6263 *it = dev_get_drvdata(dev);
> > +       int ret;
> > +
> > +       ret = it6263_lvds_set_i2c_addr(it);
> > +       if (ret)
> > +               return ret;
> > +
> > +       it6263_lvds_config(it);
> > +
> > +       return 0;
> > +}
> > +
> > +static const struct dev_pm_ops it6263_pm_ops = {
> > +       SET_SYSTEM_SLEEP_PM_OPS(NULL, it6263_resume) };
> > +
> >  static const struct of_device_id it6263_of_match[] = {
> >         { .compatible = "ite,it6263", },
> >         { }
> > @@ -922,6 +940,7 @@ static struct i2c_driver it6263_driver = {
> >         .probe = it6263_probe,
> >         .driver = {
> >                 .name = "it6263",
> > +               .pm = pm_sleep_ptr(&it6263_pm_ops),
> >                 .of_match_table = it6263_of_match,
> >         },
> >         .id_table = it6263_i2c_ids,
> > --
> > 2.43.0
> >
> 
> --
> Regards,
> Liu Ying

Re: [PATCH] drm/bridge: ite-it6263: Add basic resume support

[kernel test robot]

Hi Biju,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on linus/master v7.0 next-20260421]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Biju/drm-bridge-ite-it6263-Add-basic-resume-support/20260421-073706
base:   https://gitlab.freedesktop.org/drm/misc/kernel.git drm-misc-next
patch link:    https://lore.kernel.org/r/20260415113954.179006-1-biju.das.jz%40bp.renesas.com
patch subject: [PATCH] drm/bridge: ite-it6263: Add basic resume support
config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20260422/202604221736.zHLIEw3V-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 15.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260422/202604221736.zHLIEw3V-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202604221736.zHLIEw3V-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/bridge/ite-it6263.c:909:12: warning: 'it6263_resume' defined but not used [-Wunused-function]
     909 | static int it6263_resume(struct device *dev)
         |            ^~~~~~~~~~~~~


vim +/it6263_resume +909 drivers/gpu/drm/bridge/ite-it6263.c

   908	
 > 909	static int it6263_resume(struct device *dev)
   910	{
   911		struct it6263 *it = dev_get_drvdata(dev);
   912		int ret;
   913	
   914		ret = it6263_lvds_set_i2c_addr(it);
   915		if (ret)
   916			return ret;
   917	
   918		it6263_lvds_config(it);
   919	
   920		return 0;
   921	}
   922	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

RE: [PATCH] drm/bridge: ite-it6263: Add basic resume support

[Biju Das]

Hi kernel test robot,

> -----Original Message-----
> From: kernel test robot <lkp@intel.com>
> Sent: 22 April 2026 10:37
> Subject: Re: [PATCH] drm/bridge: ite-it6263: Add basic resume support
> 
> Hi Biju,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on drm-misc/drm-misc-next] [also build test WARNING on linus/master v7.0 next-
> 20260421] [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-
> format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Biju/drm-bridge-ite-it6263-Add-basic-resume-
> support/20260421-073706
> base:   https://gitlab.freedesktop.org/drm/misc/kernel.git drm-misc-next
> patch link:    https://lore.kernel.org/r/20260415113954.179006-1-biju.das.jz%40bp.renesas.com
> patch subject: [PATCH] drm/bridge: ite-it6263: Add basic resume support
> config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20260422/202604221736.zHLIEw3V-
> lkp@intel.com/config)
> compiler: m68k-linux-gcc (GCC) 15.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-
> ci/archive/20260422/202604221736.zHLIEw3V-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit),
> kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes:
> | https://lore.kernel.org/oe-kbuild-all/202604221736.zHLIEw3V-lkp@intel.
> | com/
> 
> All warnings (new ones prefixed by >>):
> 
> >> drivers/gpu/drm/bridge/ite-it6263.c:909:12: warning: 'it6263_resume'
> >> defined but not used [-Wunused-function]
>      909 | static int it6263_resume(struct device *dev)
>          |            ^~~~~~~~~~~~~


This patch is now superseded [1]

[1] https://lore.kernel.org/all/20260421105334.43411-1-biju.das.jz@bp.renesas.com/

Cheers,
Biju