| Message ID | 1471058078-5579-3-git-send-email-sre@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Aug 13, 2016 at 05:14:33AM +0200, Sebastian Reichel wrote: > From: NeilBrown <neilb@suse.de> > > A "tty slave" is a device connected via UART. It may need a driver to, > for example, power the device on when the tty is opened, and power it > off when the tty is released. > > Signed-off-by: NeilBrown <neilb@suse.de> > Signed-off-by: Sebastian Reichel <sre@kernel.org> > --- > Documentation/devicetree/bindings/serial/8250.txt | 4 ++++ > drivers/tty/tty_io.c | 6 ++++++ > 2 files changed, 10 insertions(+) > > diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt > index f5561ac7e17e..ecb74730f71b 100644 > --- a/Documentation/devicetree/bindings/serial/8250.txt > +++ b/Documentation/devicetree/bindings/serial/8250.txt > @@ -46,6 +46,10 @@ Optional properties: > line respectively. It will use specified GPIO instead of the peripheral > function pin for the UART feature. If unsure, don't specify this property. > > +Optional child node: > +- a device connected to the uart can be specified as child node with > + compatible value. > + > Note: > * fsl,ns16550: > ------------ > diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c > index 734a635e7363..39ff5dcdfd50 100644 > --- a/drivers/tty/tty_io.c > +++ b/drivers/tty/tty_io.c > @@ -95,6 +95,7 @@ > #include <linux/seq_file.h> > #include <linux/serial.h> > #include <linux/ratelimit.h> > +#include <linux/of_platform.h> > > #include <linux/uaccess.h> > > @@ -3317,6 +3318,11 @@ struct device *tty_register_device_attr(struct tty_driver *driver, > retval = device_register(dev); > if (retval) > goto error; > + if (device && device->of_node) > + /* Children are platform devices and will be > + * runtime_pm managed by this tty. > + */ > + of_platform_populate(device->of_node, NULL, NULL, dev); Why are these platform devices? And why only OF? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, On Sat, Aug 13, 2016 at 12:03:45PM +0200, Greg Kroah-Hartman wrote: > On Sat, Aug 13, 2016 at 05:14:33AM +0200, Sebastian Reichel wrote: > > From: NeilBrown <neilb@suse.de> > > > > A "tty slave" is a device connected via UART. It may need a driver to, > > for example, power the device on when the tty is opened, and power it > > off when the tty is released. > > > > Signed-off-by: NeilBrown <neilb@suse.de> > > Signed-off-by: Sebastian Reichel <sre@kernel.org> > > --- > > Documentation/devicetree/bindings/serial/8250.txt | 4 ++++ > > drivers/tty/tty_io.c | 6 ++++++ > > 2 files changed, 10 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt > > index f5561ac7e17e..ecb74730f71b 100644 > > --- a/Documentation/devicetree/bindings/serial/8250.txt > > +++ b/Documentation/devicetree/bindings/serial/8250.txt > > @@ -46,6 +46,10 @@ Optional properties: > > line respectively. It will use specified GPIO instead of the peripheral > > function pin for the UART feature. If unsure, don't specify this property. > > > > +Optional child node: > > +- a device connected to the uart can be specified as child node with > > + compatible value. > > + > > Note: > > * fsl,ns16550: > > ------------ > > diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c > > index 734a635e7363..39ff5dcdfd50 100644 > > --- a/drivers/tty/tty_io.c > > +++ b/drivers/tty/tty_io.c > > @@ -95,6 +95,7 @@ > > #include <linux/seq_file.h> > > #include <linux/serial.h> > > #include <linux/ratelimit.h> > > +#include <linux/of_platform.h> > > > > #include <linux/uaccess.h> > > > > @@ -3317,6 +3318,11 @@ struct device *tty_register_device_attr(struct tty_driver *driver, > > retval = device_register(dev); > > if (retval) > > goto error; > > + if (device && device->of_node) > > + /* Children are platform devices and will be > > + * runtime_pm managed by this tty. > > + */ > > + of_platform_populate(device->of_node, NULL, NULL, dev); > > Why are these platform devices? > And why only OF? I just took this patch over from Neil to get bluetooth working on N900/N950. Both of them are DT only (well N900 still has boardcode, but that will be removed shortly), so it was enough for me. I guess you have something in mind, that's similar to e.g. i2c and spi with a serial_client device and support to instanciate it from DT, ACPI and boardcode? -- Sebastian
On Sat 2016-08-13 12:03:45, Greg Kroah-Hartman wrote: > On Sat, Aug 13, 2016 at 05:14:33AM +0200, Sebastian Reichel wrote: > > From: NeilBrown <neilb@suse.de> > > > > A "tty slave" is a device connected via UART. It may need a driver to, > > for example, power the device on when the tty is opened, and power it > > off when the tty is released. > > > > Signed-off-by: NeilBrown <neilb@suse.de> > > Signed-off-by: Sebastian Reichel <sre@kernel.org> Acked-by: Pavel Machek <pavel@ucw.cz> > > @@ -3317,6 +3318,11 @@ struct device *tty_register_device_attr(struct tty_driver *driver, > > retval = device_register(dev); > > if (retval) > > goto error; > > + if (device && device->of_node) > > + /* Children are platform devices and will be > > + * runtime_pm managed by this tty. > > + */ > > + of_platform_populate(device->of_node, NULL, NULL, dev); > > Why are these platform devices? And why only OF? OF based systems are the only ones that have this problem, so that's the only place where we can test this solution. Given that these devices are connected over the UART, it seems right to categorize them as platform devices... You can't connect PCI, SATA or USB device over UART port. Pavel
On Sun, Aug 14, 2016 at 10:48:22AM +0200, Pavel Machek wrote: > On Sat 2016-08-13 12:03:45, Greg Kroah-Hartman wrote: > > On Sat, Aug 13, 2016 at 05:14:33AM +0200, Sebastian Reichel wrote: > > > From: NeilBrown <neilb@suse.de> > > > > > > A "tty slave" is a device connected via UART. It may need a driver to, > > > for example, power the device on when the tty is opened, and power it > > > off when the tty is released. > > > > > > Signed-off-by: NeilBrown <neilb@suse.de> > > > Signed-off-by: Sebastian Reichel <sre@kernel.org> > > Acked-by: Pavel Machek <pavel@ucw.cz> > > > > @@ -3317,6 +3318,11 @@ struct device *tty_register_device_attr(struct tty_driver *driver, > > > retval = device_register(dev); > > > if (retval) > > > goto error; > > > + if (device && device->of_node) > > > + /* Children are platform devices and will be > > > + * runtime_pm managed by this tty. > > > + */ > > > + of_platform_populate(device->of_node, NULL, NULL, dev); > > > > Why are these platform devices? And why only OF? > > OF based systems are the only ones that have this problem, so that's > the only place where we can test this solution. > > Given that these devices are connected over the UART, it seems right > to categorize them as platform devices... You can't connect PCI, SATA > or USB device over UART port. No, that's a total abuse of the platform bus, please don't. I've said before that a "serial" bus should be created and you can hang devices off of it. For some reason that message keeps getting ignored... thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Aug 13, 2016 at 10:31:24PM +0200, Sebastian Reichel wrote: > Hi, > > On Sat, Aug 13, 2016 at 12:03:45PM +0200, Greg Kroah-Hartman wrote: > > On Sat, Aug 13, 2016 at 05:14:33AM +0200, Sebastian Reichel wrote: > > > From: NeilBrown <neilb@suse.de> > > > > > > A "tty slave" is a device connected via UART. It may need a driver to, > > > for example, power the device on when the tty is opened, and power it > > > off when the tty is released. > > > > > > Signed-off-by: NeilBrown <neilb@suse.de> > > > Signed-off-by: Sebastian Reichel <sre@kernel.org> > > > --- > > > Documentation/devicetree/bindings/serial/8250.txt | 4 ++++ > > > drivers/tty/tty_io.c | 6 ++++++ > > > 2 files changed, 10 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt > > > index f5561ac7e17e..ecb74730f71b 100644 > > > --- a/Documentation/devicetree/bindings/serial/8250.txt > > > +++ b/Documentation/devicetree/bindings/serial/8250.txt > > > @@ -46,6 +46,10 @@ Optional properties: > > > line respectively. It will use specified GPIO instead of the peripheral > > > function pin for the UART feature. If unsure, don't specify this property. > > > > > > +Optional child node: > > > +- a device connected to the uart can be specified as child node with > > > + compatible value. > > > + > > > Note: > > > * fsl,ns16550: > > > ------------ > > > diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c > > > index 734a635e7363..39ff5dcdfd50 100644 > > > --- a/drivers/tty/tty_io.c > > > +++ b/drivers/tty/tty_io.c > > > @@ -95,6 +95,7 @@ > > > #include <linux/seq_file.h> > > > #include <linux/serial.h> > > > #include <linux/ratelimit.h> > > > +#include <linux/of_platform.h> > > > > > > #include <linux/uaccess.h> > > > > > > @@ -3317,6 +3318,11 @@ struct device *tty_register_device_attr(struct tty_driver *driver, > > > retval = device_register(dev); > > > if (retval) > > > goto error; > > > + if (device && device->of_node) > > > + /* Children are platform devices and will be > > > + * runtime_pm managed by this tty. > > > + */ > > > + of_platform_populate(device->of_node, NULL, NULL, dev); > > > > Why are these platform devices? > > And why only OF? > > I just took this patch over from Neil to get bluetooth working > on N900/N950. Both of them are DT only (well N900 still has > boardcode, but that will be removed shortly), so it was enough > for me. > > I guess you have something in mind, that's similar to e.g. i2c > and spi with a serial_client device and support to instanciate > it from DT, ACPI and boardcode? I'm not going to accept a OF-only patch to the tty layer like this, especially one that abuses platform drivers. See my response to Pavel for what this "should" look like. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt index f5561ac7e17e..ecb74730f71b 100644 --- a/Documentation/devicetree/bindings/serial/8250.txt +++ b/Documentation/devicetree/bindings/serial/8250.txt @@ -46,6 +46,10 @@ Optional properties: line respectively. It will use specified GPIO instead of the peripheral function pin for the UART feature. If unsure, don't specify this property. +Optional child node: +- a device connected to the uart can be specified as child node with + compatible value. + Note: * fsl,ns16550: ------------ diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 734a635e7363..39ff5dcdfd50 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -95,6 +95,7 @@ #include <linux/seq_file.h> #include <linux/serial.h> #include <linux/ratelimit.h> +#include <linux/of_platform.h> #include <linux/uaccess.h> @@ -3317,6 +3318,11 @@ struct device *tty_register_device_attr(struct tty_driver *driver, retval = device_register(dev); if (retval) goto error; + if (device && device->of_node) + /* Children are platform devices and will be + * runtime_pm managed by this tty. + */ + of_platform_populate(device->of_node, NULL, NULL, dev); return dev;