[1/7] dm: button: add an uclass for button

Add a new uclass for button that implements two functions:
- button_get_by_label
- button_get_status

Signed-off-by: Philippe Reynes <philippe.reynes at softathome.com>
---
 drivers/Kconfig                |  2 ++
 drivers/Makefile               |  1 +
 drivers/button/Kconfig         | 12 ++++++++++
 drivers/button/Makefile        |  5 ++++
 drivers/button/button-uclass.c | 47 +++++++++++++++++++++++++++++++++++++
 include/button.h               | 53 ++++++++++++++++++++++++++++++++++++++++++
 include/dm/uclass-id.h         |  1 +
 7 files changed, 121 insertions(+)
 create mode 100644 drivers/button/Kconfig
 create mode 100644 drivers/button/Makefile
 create mode 100644 drivers/button/button-uclass.c
 create mode 100644 include/button.h

Hi Philippe,

On Mon, 13 Jul 2020 at 06:56, Philippe Reynes
<philippe.reynes at softathome.com> wrote:
>
> Add a new uclass for button that implements two functions:
> - button_get_by_label
> - button_get_status
>
> Signed-off-by: Philippe Reynes <philippe.reynes at softathome.com>
> ---
>  drivers/Kconfig                |  2 ++
>  drivers/Makefile               |  1 +
>  drivers/button/Kconfig         | 12 ++++++++++
>  drivers/button/Makefile        |  5 ++++
>  drivers/button/button-uclass.c | 47 +++++++++++++++++++++++++++++++++++++
>  include/button.h               | 53 ++++++++++++++++++++++++++++++++++++++++++
>  include/dm/uclass-id.h         |  1 +
>  7 files changed, 121 insertions(+)
>  create mode 100644 drivers/button/Kconfig
>  create mode 100644 drivers/button/Makefile
>  create mode 100644 drivers/button/button-uclass.c
>  create mode 100644 include/button.h

Reviewed-by: Simon Glass <sjg at chromium.org>

Please see below

>
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index e34a227..3cb05aa 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -14,6 +14,8 @@ source "drivers/block/Kconfig"
>
>  source "drivers/bootcount/Kconfig"
>
> +source "drivers/button/Kconfig"
> +
>  source "drivers/cache/Kconfig"
>
>  source "drivers/clk/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile
> index 94e8c5d..727a713 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0+
>
> +obj-$(CONFIG_$(SPL_TPL_)BUTTON) += button/
>  obj-$(CONFIG_$(SPL_TPL_)CACHE) += cache/
>  obj-$(CONFIG_$(SPL_TPL_)CLK) += clk/
>  obj-$(CONFIG_$(SPL_TPL_)DM) += core/
> diff --git a/drivers/button/Kconfig b/drivers/button/Kconfig
> new file mode 100644
> index 0000000..8301858
> --- /dev/null
> +++ b/drivers/button/Kconfig
> @@ -0,0 +1,12 @@
> +menu "Button Support"
> +
> +config BUTTON
> +       bool "Enable button support"
> +       depends on DM
> +       help
> +         Many boards have buttons which can be used to change behaviour (reset, ...).
> +         U-Boot provides a uclass API to implement this feature. Button drivers
> +         can provide access to board-specific buttons. Use of the device tree
> +         for configuration is encouraged.
> +
> +endmenu
> diff --git a/drivers/button/Makefile b/drivers/button/Makefile
> new file mode 100644
> index 0000000..0b4c128
> --- /dev/null
> +++ b/drivers/button/Makefile
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (C) 2020 Philippe Reynes <philippe.reynes at softathome.com>
> +
> +obj-$(CONFIG_BUTTON) += button-uclass.o
> diff --git a/drivers/button/button-uclass.c b/drivers/button/button-uclass.c
> new file mode 100644
> index 0000000..d6cda78
> --- /dev/null
> +++ b/drivers/button/button-uclass.c
> @@ -0,0 +1,47 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2020 Philippe Reynes <philippe.reynes at softathome.com>
> + *
> + * Based on led-uclass.c
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <dm/uclass-internal.h>
> +#include <button.h>

this one should go below common.h

> +
> +int button_get_by_label(const char *label, struct udevice **devp)
> +{
> +       struct udevice *dev;
> +       struct uclass *uc;
> +       int ret;
> +
> +       ret = uclass_get(UCLASS_BUTTON, &uc);
> +       if (ret)
> +               return ret;
> +       uclass_foreach_dev(dev, uc) {

uclass_id_foreach_dev

> +               struct button_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
> +
> +               /* Ignore the top-level button node */
> +               if (uc_plat->label && !strcmp(label, uc_plat->label))
> +                       return uclass_get_device_tail(dev, 0, devp);
> +       }
> +
> +       return -ENODEV;
> +}
> +
> +enum button_state_t button_get_state(struct udevice *dev)
> +{
> +       struct button_ops *ops = button_get_ops(dev);
> +
> +       if (!ops->get_state)
> +               return -ENOSYS;
> +
> +       return ops->get_state(dev);
> +}
> +
> +UCLASS_DRIVER(button) = {
> +       .id             = UCLASS_BUTTON,
> +       .name           = "button",
> +       .per_device_platdata_auto_alloc_size = sizeof(struct button_uc_plat),
> +};
> diff --git a/include/button.h b/include/button.h
> new file mode 100644
> index 0000000..333fc23
> --- /dev/null
> +++ b/include/button.h
> @@ -0,0 +1,53 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright (C) 2020 Philippe Reynes <philippe.reynes at softathome.com>
> + */
> +
> +#ifndef __BUTTON_H
> +#define __BUTTON_H
> +
> +/**
> + * struct button_uc_plat - Platform data the uclass stores about each device
> + *
> + * @label:     Button label
> + */
> +struct button_uc_plat {
> +       const char *label;
> +};
> +

comment for this enum:

> +enum button_state_t {
> +       BUTTON_OFF = 0,
> +       BUTTON_ON = 1,
> +       BUTTON_COUNT,
> +};
> +
> +struct button_ops {
> +       /**
> +        * get_state() - get the state of a button
> +        *
> +        * @dev:        button device to change
> +        * @return button state button_state_t, or -ve on error
> +        */
> +       enum button_state_t (*get_state)(struct udevice *dev);
> +};
> +
> +#define button_get_ops(dev)    ((struct button_ops *)(dev)->driver->ops)
> +
> +/**
> + * button_get_by_label() - Find a button device by label
> + *
> + * @label:     button label to look up
> + * @devp:      Returns the associated device, if found
> + * @return 0 if found, -ENODEV if not found, other -ve on error
> + */
> +int button_get_by_label(const char *label, struct udevice **devp);
> +
> +/**
> + * button_get_state() - get the state of a button
> + *
> + * @dev:       button device to change
> + * @return button state button_state_t, or -ve on error
> + */
> +enum button_state_t button_get_state(struct udevice *dev);
> +
> +#endif
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index 7837d45..85c7149 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -38,6 +38,7 @@ enum uclass_id {
>         UCLASS_BLK,             /* Block device */
>         UCLASS_BOARD,           /* Device information from hardware */
>         UCLASS_BOOTCOUNT,       /* Bootcount backing store */
> +       UCLASS_BUTTON,          /* Button */
>         UCLASS_CACHE,           /* Cache controller */
>         UCLASS_CLK,             /* Clock source, e.g. used by peripherals */
>         UCLASS_CPU,             /* CPU, typically part of an SoC */
> --
> 2.7.4
>

Regards,
Simon