[PATCH v2] gpio: samsung: add devicetree init for s3c24xx arches
Heiko Stübner
heiko at sntech.de
Wed Aug 29 17:41:31 EST 2012
Am Mittwoch, 29. August 2012, 01:09:37 schrieb Kukjin Kim:
> On 08/28/12 14:55, Heiko Stübner wrote:
> > Until now the Exynos-SoC was the only Samsung-SoC supporting the GPIOs
> > via the device tree. This patch implements dt-support for the
> > s3c24xx arches.
> >
> > The controllers contain only 3 cells, as the underlying gpio controller
> > does not support controlling the drive strength on a gpio level.
> >
> > Tested with the gpio-keys driver on a s3c2416 based machine.
> >
> > Signed-off-by: Heiko Stuebner<heiko at sntech.de>
> > Reviewed-by: Thomas Abraham<thomas.abraham at linaro.org>
>
> Yeah, looks good to me...
>
> Acked-by: Kukjin Kim <kgene.kim at samsung.com>
>
> BTW, I'm not sure when we can support device tree for S3C24XX :-)
As you might've guessed, I'm working on it :-) .
Thanks to some engineers of yours at least the s3c2416/s3c2450 SoCs share a
lot of components with all the newer ones and their drivers already contain
the dt bindings - mostly thanks to Thomas I think.
So the only real hard part I need to figure out for now is, how to implement
the interrupt bindings. Then I'll already have sdhci, rtc, watchdog, serial
and i2c available.
And if I also manage to get the dma into dt, I'll also have the s3c64xx-spi
available.
So, all in all, this does sound solvable :-)
Heiko
> Thanks.
>
> Best regards,
> Kgene.
> --
> Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
> SW Solution Development Team, Samsung Electronics Co., Ltd.
>
> > ---
> > changes since v1:
> > update bindings documentation to address SoC specific issues
> >
> > .../devicetree/bindings/gpio/gpio-samsung.txt | 43 +++++++++++++
> > drivers/gpio/gpio-samsung.c | 63
> > ++++++++++++++++++++ 2 files changed, 106 insertions(+), 0
> > deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
> > b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt index
> > 5375625..f1e5dfe 100644
> > --- a/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
> > +++ b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
> >
> > @@ -39,3 +39,46 @@ Example:
> > #gpio-cells =<4>;
> > gpio-controller;
> >
> > };
> >
> > +
> > +
> > +Samsung S3C24XX GPIO Controller
> > +
> > +Required properties:
> > +- compatible: Compatible property value should be
> > "samsung,s3c24xx-gpio". +
> > +- reg: Physical base address of the controller and length of memory
> > mapped + region.
> > +
> > +- #gpio-cells: Should be 3. The syntax of the gpio specifier used by
> > client nodes + should be the following with values derived from the SoC
> > user manual. +<[phandle of the gpio controller node]
> > + [pin number within the gpio controller]
> > + [mux function]
> > + [flags and pull up/down]
> > +
> > + Values for gpio specifier:
> > + - Pin number: depending on the controller a number from 0 up to 15.
> > + - Mux function: Depending on the SoC and the gpio bank the gpio can be
> > set + as input, output or a special function
> > + - Flags and Pull Up/Down: the values to use differ for the individual
> > SoCs + example S3C2416/S3C2450:
> > + 0 - Pull Up/Down Disabled.
> > + 1 - Pull Down Enabled.
> > + 2 - Pull Up Enabled.
> > + Bit 16 (0x00010000) - Input is active low.
> > + Consult the user manual for the correct values of Mux and Pull
> > Up/Down. +
> > +- gpio-controller: Specifies that the node is a gpio controller.
> > +- #address-cells: should be 1.
> > +- #size-cells: should be 1.
> > +
> > +Example:
> > +
> > + gpa: gpio-controller at 56000000 {
> > + #address-cells =<1>;
> > + #size-cells =<1>;
> > + compatible = "samsung,s3c24xx-gpio";
> > + reg =<0x56000000 0x10>;
> > + #gpio-cells =<3>;
> > + gpio-controller;
> > + };
> > diff --git a/drivers/gpio/gpio-samsung.c b/drivers/gpio/gpio-samsung.c
> > index ba126cc..54f6663 100644
> > --- a/drivers/gpio/gpio-samsung.c
> > +++ b/drivers/gpio/gpio-samsung.c
> > @@ -938,6 +938,67 @@ static void __init samsung_gpiolib_add(struct
> > samsung_gpio_chip *chip)
> >
> > s3c_gpiolib_track(chip);
> >
> > }
> >
> > +#if defined(CONFIG_PLAT_S3C24XX)&& defined(CONFIG_OF)
> > +static int s3c24xx_gpio_xlate(struct gpio_chip *gc,
> > + const struct of_phandle_args *gpiospec, u32 *flags)
> > +{
> > + unsigned int pin;
> > +
> > + if (WARN_ON(gc->of_gpio_n_cells< 3))
> > + return -EINVAL;
> > +
> > + if (WARN_ON(gpiospec->args_count< gc->of_gpio_n_cells))
> > + return -EINVAL;
> > +
> > + if (gpiospec->args[0]> gc->ngpio)
> > + return -EINVAL;
> > +
> > + pin = gc->base + gpiospec->args[0];
> > +
> > + if (s3c_gpio_cfgpin(pin, S3C_GPIO_SFN(gpiospec->args[1])))
> > + pr_warn("gpio_xlate: failed to set pin function\n");
> > + if (s3c_gpio_setpull(pin, gpiospec->args[2]& 0xffff))
> > + pr_warn("gpio_xlate: failed to set pin pull up/down\n");
> > +
> > + if (flags)
> > + *flags = gpiospec->args[2]>> 16;
> > +
> > + return gpiospec->args[0];
> > +}
> > +
> > +static const struct of_device_id s3c24xx_gpio_dt_match[] __initdata = {
> > + { .compatible = "samsung,s3c24xx-gpio", },
> > + {}
> > +};
> > +
> > +static __init void s3c24xx_gpiolib_attach_ofnode(struct
> > samsung_gpio_chip *chip, + u64 base, u64 offset)
> > +{
> > + struct gpio_chip *gc =&chip->chip;
> > + u64 address;
> > +
> > + if (!of_have_populated_dt())
> > + return;
> > +
> > + address = chip->base ? base + ((u32)chip->base& 0xfff) : base +
> > offset; + gc->of_node = of_find_matching_node_by_address(NULL,
> > + s3c24xx_gpio_dt_match, address);
> > + if (!gc->of_node) {
> > + pr_info("gpio: device tree node not found for gpio controller"
> > + " with base address %08llx\n", address);
> > + return;
> > + }
> > + gc->of_gpio_n_cells = 3;
> > + gc->of_xlate = s3c24xx_gpio_xlate;
> > +}
> > +#elif defined(CONFIG_PLAT_S3C24XX)
> > +static __init void s3c24xx_gpiolib_attach_ofnode(struct
> > samsung_gpio_chip *chip, + u64 base, u64 offset)
> > +{
> > + return;
> > +}
> > +#endif /* defined(CONFIG_PLAT_S3C24XX)&& defined(CONFIG_OF) */
> > +
> >
> > static void __init s3c24xx_gpiolib_add_chips(struct samsung_gpio_chip
> > *chip,
> >
> > int nr_chips, void __iomem *base)
> >
> > {
> >
> > @@ -962,6 +1023,8 @@ static void __init s3c24xx_gpiolib_add_chips(struct
> > samsung_gpio_chip *chip,
> >
> > gc->direction_output = samsung_gpiolib_2bit_output;
> >
> > samsung_gpiolib_add(chip);
> >
> > +
> > + s3c24xx_gpiolib_attach_ofnode(chip, S3C24XX_PA_GPIO, i * 0x10);
> >
> > }
> >
> > }
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