| Message ID | 20181010142504.233467-9-lkundrak@v3.sk (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | OLPC 1.75 Keyboard/Touchpad fixes | expand |
On Wed, Oct 10, 2018 at 04:25:04PM +0200, Lubomir Rintel wrote: > Take the GPIO lines are used by the SP. The driver doesn't touch the > lines -- this is done to disallow anything else from fiddling with > them because that would confuse the SP firmware. > > Also, the lines are now nicely visible in /sys/kernel/debug/gpio. Linus, is this something that should be handled by GPIO "hogs"? > > Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> > --- > drivers/input/serio/olpc_apsp.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/drivers/input/serio/olpc_apsp.c b/drivers/input/serio/olpc_apsp.c > index fe9e19014e70..287759c5f36d 100644 > --- a/drivers/input/serio/olpc_apsp.c > +++ b/drivers/input/serio/olpc_apsp.c > @@ -24,6 +24,7 @@ > #include <linux/slab.h> > #include <linux/delay.h> > #include <linux/clk.h> > +#include <linux/gpio/consumer.h> > > /* > * The OLPC XO-1.75 and XO-4 laptops do not have a hardware PS/2 controller. > @@ -76,6 +77,8 @@ struct olpc_apsp { > struct serio *padio; > void __iomem *base; > struct clk *clk; > + struct gpio_desc *clk_gpio; > + struct gpio_desc *data_gpio; > int open_count; > int irq; > }; > @@ -211,6 +214,16 @@ static int olpc_apsp_probe(struct platform_device *pdev) > if (IS_ERR(priv->clk)) > return PTR_ERR(priv->clk); > > + priv->clk_gpio = devm_gpiod_get_optional(&pdev->dev, "clk", > + GPIOD_ASIS); > + if (IS_ERR(priv->clk_gpio)) > + return PTR_ERR(priv->clk_gpio); > + > + priv->data_gpio = devm_gpiod_get_optional(&pdev->dev, "data", > + GPIOD_ASIS); > + if (IS_ERR(priv->data_gpio)) > + return PTR_ERR(priv->data_gpio); > + > /* KEYBOARD */ > kb_serio = kzalloc(sizeof(struct serio), GFP_KERNEL); > if (!kb_serio) > -- > 2.19.0 >
On Wed, Oct 10, 2018 at 10:10:13AM -0700, Dmitry Torokhov wrote: > On Wed, Oct 10, 2018 at 04:25:04PM +0200, Lubomir Rintel wrote: > > Take the GPIO lines are used by the SP. The driver doesn't touch the > > lines -- this is done to disallow anything else from fiddling with > > them because that would confuse the SP firmware. > > > > Also, the lines are now nicely visible in /sys/kernel/debug/gpio. > > Linus, is this something that should be handled by GPIO "hogs"? Argh, meant to add Linus Walleij here. > > > > > Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> > > --- > > drivers/input/serio/olpc_apsp.c | 13 +++++++++++++ > > 1 file changed, 13 insertions(+) > > > > diff --git a/drivers/input/serio/olpc_apsp.c b/drivers/input/serio/olpc_apsp.c > > index fe9e19014e70..287759c5f36d 100644 > > --- a/drivers/input/serio/olpc_apsp.c > > +++ b/drivers/input/serio/olpc_apsp.c > > @@ -24,6 +24,7 @@ > > #include <linux/slab.h> > > #include <linux/delay.h> > > #include <linux/clk.h> > > +#include <linux/gpio/consumer.h> > > > > /* > > * The OLPC XO-1.75 and XO-4 laptops do not have a hardware PS/2 controller. > > @@ -76,6 +77,8 @@ struct olpc_apsp { > > struct serio *padio; > > void __iomem *base; > > struct clk *clk; > > + struct gpio_desc *clk_gpio; > > + struct gpio_desc *data_gpio; > > int open_count; > > int irq; > > }; > > @@ -211,6 +214,16 @@ static int olpc_apsp_probe(struct platform_device *pdev) > > if (IS_ERR(priv->clk)) > > return PTR_ERR(priv->clk); > > > > + priv->clk_gpio = devm_gpiod_get_optional(&pdev->dev, "clk", > > + GPIOD_ASIS); > > + if (IS_ERR(priv->clk_gpio)) > > + return PTR_ERR(priv->clk_gpio); > > + > > + priv->data_gpio = devm_gpiod_get_optional(&pdev->dev, "data", > > + GPIOD_ASIS); > > + if (IS_ERR(priv->data_gpio)) > > + return PTR_ERR(priv->data_gpio); > > + > > /* KEYBOARD */ > > kb_serio = kzalloc(sizeof(struct serio), GFP_KERNEL); > > if (!kb_serio) > > -- > > 2.19.0 > > > > -- > Dmitry
Hi Lubomir, thanks for your patch! On Wed, Oct 10, 2018 at 4:26 PM Lubomir Rintel <lkundrak@v3.sk> wrote: > Take the GPIO lines are used by the SP. The driver doesn't touch the > lines -- this is done to disallow anything else from fiddling with > them because that would confuse the SP firmware. > > Also, the lines are now nicely visible in /sys/kernel/debug/gpio. > > Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Sadly I do not think this is the right way to do this these days. In the past I would have agreed. A few months back, Qualcomm engineers working on ACPI support ran into similar issues: there were GPIO lines that could not be touched by the kernel because they were used by firmware (BIOS). The solution we devised can be seen in commit 726cb3ba49692bdae6caff457755e7cdb432efa4 "gpiolib: Support 'gpio-reserved-ranges' property" which adds a "valid mask" to struct gpio_chip. It is further refined in the lates working kernel code to make it easy for users to set up a custom valid_mask. https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git/commit/?h=devel&id=f8ec92a9f63b3b11e399409141b7868bb405e6b5 So what you should do is modify the platform set-up for the OLPC to mask off these GPIO lines as invalid since they are used by the firmware and Linux should not touch them. Sadly I don't know which GPIO driver the XO1 is using, but if you tell us I bet me or Andy will be able to help you out in finding the right spot to patch. Yours, Linus Walleij
On Wed 2018-10-10 16:25:04, Lubomir Rintel wrote: > Take the GPIO lines are used by the SP. The driver doesn't touch the > lines -- this is done to disallow anything else from fiddling with > them because that would confuse the SP firmware. > > Also, the lines are now nicely visible in /sys/kernel/debug/gpio. > > Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Acked-by: Pavel Machek <pavel@ucw.cz>
diff --git a/drivers/input/serio/olpc_apsp.c b/drivers/input/serio/olpc_apsp.c index fe9e19014e70..287759c5f36d 100644 --- a/drivers/input/serio/olpc_apsp.c +++ b/drivers/input/serio/olpc_apsp.c @@ -24,6 +24,7 @@ #include <linux/slab.h> #include <linux/delay.h> #include <linux/clk.h> +#include <linux/gpio/consumer.h> /* * The OLPC XO-1.75 and XO-4 laptops do not have a hardware PS/2 controller. @@ -76,6 +77,8 @@ struct olpc_apsp { struct serio *padio; void __iomem *base; struct clk *clk; + struct gpio_desc *clk_gpio; + struct gpio_desc *data_gpio; int open_count; int irq; }; @@ -211,6 +214,16 @@ static int olpc_apsp_probe(struct platform_device *pdev) if (IS_ERR(priv->clk)) return PTR_ERR(priv->clk); + priv->clk_gpio = devm_gpiod_get_optional(&pdev->dev, "clk", + GPIOD_ASIS); + if (IS_ERR(priv->clk_gpio)) + return PTR_ERR(priv->clk_gpio); + + priv->data_gpio = devm_gpiod_get_optional(&pdev->dev, "data", + GPIOD_ASIS); + if (IS_ERR(priv->data_gpio)) + return PTR_ERR(priv->data_gpio); + /* KEYBOARD */ kb_serio = kzalloc(sizeof(struct serio), GFP_KERNEL); if (!kb_serio)
Take the GPIO lines are used by the SP. The driver doesn't touch the lines -- this is done to disallow anything else from fiddling with them because that would confuse the SP firmware. Also, the lines are now nicely visible in /sys/kernel/debug/gpio. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> --- drivers/input/serio/olpc_apsp.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)