Re: [PATCH 1/3] ARM: mediatek: Add Reset Controller for MediaTek SoC

[Matthias Brugger]

2014-10-30 4:12 GMT+01:00  <flora.fu@xxxxxxxxxxxx>:
> From: Flora Fu <flora.fu@xxxxxxxxxxxx>
>
> Add a driver in reset controller.
>
> Signed-off-by: Flora Fu <flora.fu@xxxxxxxxxxxx>
> ---
>  drivers/reset/Makefile    |   1 +
>  drivers/reset/reset-mtk.c | 149 ++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 150 insertions(+)
>  create mode 100644 drivers/reset/reset-mtk.c
>
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index 60fed3d..adcebdf 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -2,3 +2,4 @@ obj-$(CONFIG_RESET_CONTROLLER) += core.o
>  obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
>  obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
>  obj-$(CONFIG_ARCH_STI) += sti/
> +obj-$(CONFIG_ARCH_MEDIATEK) += reset-mtk.o
> diff --git a/drivers/reset/reset-mtk.c b/drivers/reset/reset-mtk.c
> new file mode 100644
> index 0000000..e2211f7
> --- /dev/null
> +++ b/drivers/reset/reset-mtk.c
> @@ -0,0 +1,149 @@
> +/*
> + * Copyright (c) 2014 MediaTek Inc.
> + * Author: Flora.Fu <flora.fu@xxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/reset-controller.h>
> +#include <linux/slab.h>
> +
> +struct mt_reset_data {

Please rename mt_ prefixes to the prefix mtk_ to keep consistent
naming in the kernel.

> +       struct regmap *regmap;
> +       unsigned int resetbase;
> +       unsigned int size;
> +       struct reset_controller_dev rcdev;
> +};
> +
> +static int mt_reset_assert(struct reset_controller_dev *rcdev,
> +                             unsigned long id)
> +{
> +       struct regmap *regmap;
> +       unsigned addr;
> +       unsigned mask;
> +       struct mt_reset_data *data = container_of(rcdev,
> +                                                    struct mt_reset_data,
> +                                                    rcdev);
> +       regmap = data->regmap;
> +       addr = data->resetbase + ((id / 32) << 2);
> +       mask = BIT(id % 32);
> +
> +       return regmap_update_bits(regmap, addr, mask, mask);
> +}
> +
> +static int mt_reset_deassert(struct reset_controller_dev *rcdev,
> +                               unsigned long id)
> +{
> +       struct regmap *regmap;
> +       unsigned addr;
> +       unsigned mask;
> +       struct mt_reset_data *data = container_of(rcdev,
> +                                                    struct mt_reset_data,
> +                                                    rcdev);
> +
> +       regmap = data->regmap;
> +       addr = data->resetbase + ((id / 32) << 2);
> +       mask = BIT(id % 32);
> +
> +       return regmap_update_bits(regmap, addr, mask, ~mask);
> +}
> +
> +static struct reset_control_ops mt_reset_ops = {
> +       .assert = mt_reset_assert,
> +       .deassert = mt_reset_deassert,
> +};
> +
> +static int mt_reset_probe(struct platform_device *pdev)
> +{
> +       struct mt_reset_data *data;
> +       struct device_node *np = pdev->dev.of_node;
> +       unsigned int resetbase;
> +       unsigned int width;
> +       int ret;
> +
> +       data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +       if (!data)
> +               return -ENOMEM;
> +
> +       data->regmap = syscon_regmap_lookup_by_phandle(np,
> +               "mediatek,syscon-reset");
> +       if (IS_ERR(data->regmap)) {
> +               dev_err(&pdev->dev, "couldn't get syscon-reset regmap\n");
> +               return PTR_ERR(data->regmap);
> +       }
> +
> +       ret = of_property_read_u32_index(np, "mediatek,syscon-reset", 1,
> +               &resetbase);
> +       if (ret) {
> +               dev_err(&pdev->dev, "couldn't read reset base from syscon!\n");
> +               return -EINVAL;
> +       }
> +
> +       ret = of_property_read_u32_index(np, "mediatek,syscon-reset", 2,
> +               &width);
> +       if (ret) {
> +               dev_err(&pdev->dev, "couldn't read reset bytes from syscon!\n");
> +               return -EINVAL;
> +       }
> +
> +       data->resetbase = resetbase;
> +       data->size = width >> 2;
> +       data->rcdev.owner = THIS_MODULE;
> +       data->rcdev.nr_resets = data->size * 32;
> +       data->rcdev.ops = &mt_reset_ops;
> +       data->rcdev.of_node = pdev->dev.of_node;
> +
> +       return reset_controller_register(&data->rcdev);
> +}
> +
> +static int mt_reset_remove(struct platform_device *pdev)
> +{
> +       struct mt_reset_data *data = platform_get_drvdata(pdev);
> +
> +       reset_controller_unregister(&data->rcdev);
> +       return 0;
> +}
> +
> +static const struct of_device_id mt_reset_dt_ids[] = {
> +       { .compatible = "mediatek,reset", },
> +       {},
> +};
> +MODULE_DEVICE_TABLE(of, mt_reset_dt_ids);
> +
> +static struct platform_driver mt_reset_driver = {
> +       .probe = mt_reset_probe,
> +       .remove = mt_reset_remove,
> +       .driver = {
> +               .name = "mtk-reset",
> +               .owner = THIS_MODULE,
> +               .of_match_table = mt_reset_dt_ids,
> +       },
> +};
> +
> +static int __init mt_reset_init(void)
> +{
> +       return platform_driver_register(&mt_reset_driver);
> +}
> +module_init(mt_reset_init);
> +
> +static void __exit mt_reset_exit(void)
> +{
> +       platform_driver_unregister(&mt_reset_driver);
> +}
> +module_exit(mt_reset_exit);
> +
> +MODULE_AUTHOR("Flora Fu <flora.fu@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("MediaTek SoC Generic Reset Controller");
> +MODULE_LICENSE("GPL");
> --
> 1.8.1.1.dirty
>



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