Hi,
On 27/04/2018 14:53, Mario Six wrote:
> Some reset lines are implemented by toggling the line via a GPIO.
>
> Add a driver to properly drive such reset lines.
You are defining a "gpio-reset" binding which has always been rejected
under Linux, so I'm not sure it's a good idea to add it in U-Boot only...
Neil
>
> Signed-off-by: Mario Six <mario....@gdsys.cc>
> ---
>
> v1 -> v2:
> No changes
>
> ---
> drivers/reset/Kconfig | 7 ++++
> drivers/reset/Makefile | 1 +
> drivers/reset/gpio-reset.c | 100
> +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 108 insertions(+)
> create mode 100644 drivers/reset/gpio-reset.c
>
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index 33c39b7fb6..b6e1da009c 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -98,4 +98,11 @@ config RESET_SOCFPGA
> help
> Support for reset controller on SoCFPGA platform.
>
> +config GPIO_RESET
> + bool "Reset driver for GPIO-based reset lines"
> + depends on DM_RESET
> + help
> + Support a generic reset controller that encapsulates a number of
> + GPIOs of which each controls a single reset line.
> +
> endmenu
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index ad08be4c8c..4a9d4006a3 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -15,3 +15,4 @@ obj-$(CONFIG_AST2500_RESET) += ast2500-reset.o
> obj-$(CONFIG_RESET_ROCKCHIP) += reset-rockchip.o
> obj-$(CONFIG_RESET_MESON) += reset-meson.o
> obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
> +obj-$(CONFIG_GPIO_RESET) += gpio-reset.o
> diff --git a/drivers/reset/gpio-reset.c b/drivers/reset/gpio-reset.c
> new file mode 100644
> index 0000000000..52dd47df60
> --- /dev/null
> +++ b/drivers/reset/gpio-reset.c
> @@ -0,0 +1,100 @@
> +/*
> + * (C) Copyright 2017
> + * Mario Six, Guntermann & Drunck GmbH, mario....@gdsys.cc
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <reset-uclass.h>
> +#include <asm/gpio.h>
> +
> +struct gpio_reset_priv {
> + struct gpio_desc gpios[16];
> + uint gpio_num;
> +};
> +
> +static int gpio_reset_request(struct reset_ctl *reset_ctl)
> +{
> + struct gpio_reset_priv *priv = dev_get_priv(reset_ctl->dev);
> +
> + debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
> + reset_ctl->dev, reset_ctl->id);
> +
> + /* Reset ID = number of GPIO in list */
> + if (reset_ctl->id >= priv->gpio_num)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static int gpio_reset_free(struct reset_ctl *reset_ctl)
> +{
> + debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
> + reset_ctl->dev, reset_ctl->id);
> +
> + return 0;
> +}
> +
> +static int gpio_reset_assert(struct reset_ctl *reset_ctl)
> +{
> + struct gpio_reset_priv *priv = dev_get_priv(reset_ctl->dev);
> +
> + debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
> + reset_ctl->dev, reset_ctl->id);
> +
> + dm_gpio_set_value(&priv->gpios[reset_ctl->id], 1);
> +
> + return 0;
> +}
> +
> +static int gpio_reset_deassert(struct reset_ctl *reset_ctl)
> +{
> + struct gpio_reset_priv *priv = dev_get_priv(reset_ctl->dev);
> +
> + debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
> + reset_ctl->dev, reset_ctl->id);
> +
> + dm_gpio_set_value(&priv->gpios[reset_ctl->id], 0);
> +
> + return 0;
> +}
> +
> +struct reset_ops gpio_reset_ops = {
> + .request = gpio_reset_request,
> + .free = gpio_reset_free,
> + .rst_assert = gpio_reset_assert,
> + .rst_deassert = gpio_reset_deassert,
> +};
> +
> +static int gpio_reset_probe(struct udevice *dev)
> +{
> + struct gpio_reset_priv *priv = dev_get_priv(dev);
> + int ret;
> +
> + debug("%s(dev=%p)\n", __func__, dev);
> +
> + ret = gpio_request_list_by_name(dev, "gpios", priv->gpios,
> + ARRAY_SIZE(priv->gpios), GPIOD_IS_OUT);
> + if (ret <= 0)
> + return ret;
> +
> + priv->gpio_num = ret;
> +
> + return 0;
> +}
> +
> +static const struct udevice_id gpio_reset[] = {
> + { .compatible = "gpio-reset", },
> + { /* sentinel */ }
> +};
> +
> +U_BOOT_DRIVER(gpio_reset) = {
> + .name = "gpio_reset",
> + .id = UCLASS_RESET,
> + .of_match = gpio_reset,
> + .probe = gpio_reset_probe,
> + .ops = &gpio_reset_ops,
> + .priv_auto_alloc_size = sizeof(struct gpio_reset_priv),
> +};
> --
> 2.16.1
>
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