[U-Boot] [PATCH 07/11] clk: Add fixed-factor clock driver

Alexander Graf
2019-01-17T18:20:33Z

On 01/17/2019 11:39 AM, Anup Patel wrote:
> This patch adds fixed-factor clock driver which derives clock
> rate by dividing (div) and multiplying (mult) fixed factors
> to a parent clock.
>
> Signed-off-by: Anup Patel <anup.patel@wdc.com>
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> ---
> drivers/clk/Makefile | 4 +-
> drivers/clk/clk_fixed_factor.c | 74 ++++++++++++++++++++++++++++++++++
> 2 files changed, 77 insertions(+), 1 deletion(-)
> create mode 100644 drivers/clk/clk_fixed_factor.c
>
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index 2f4446568c..fa59259ea3 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -4,7 +4,9 @@
> # Wolfgang Denk, DENX Software Engineering, wd at denx.de.
> #
>
> -obj-$(CONFIG_$(SPL_TPL_)CLK) += clk-uclass.o clk_fixed_rate.o
> +obj-$(CONFIG_$(SPL_TPL_)CLK) += clk-uclass.o
> +obj-$(CONFIG_$(SPL_TPL_)CLK) += clk_fixed_rate.o
> +obj-$(CONFIG_$(SPL_TPL_)CLK) += clk_fixed_factor.o
>
> obj-y += imx/
> obj-y += tegra/
> diff --git a/drivers/clk/clk_fixed_factor.c b/drivers/clk/clk_fixed_factor.c
> new file mode 100644
> index 0000000000..eab1724c26
> --- /dev/null
> +++ b/drivers/clk/clk_fixed_factor.c
> @@ -0,0 +1,74 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019 Western Digital Corporation or its affiliates.
> + *
> + * Author: Anup Patel <anup.patel@wdc.com>
> + */
> +
> +#include <common.h>
> +#include <clk-uclass.h>
> +#include <div64.h>
> +#include <dm.h>
> +
> +struct clk_fixed_factor {
> + struct clk parent;
> + unsigned int div;
> + unsigned int mult;
> +};
> +
> +#define to_clk_fixed_factor(dev) \
> + ((struct clk_fixed_factor *)dev_get_platdata(dev))
> +
> +static ulong clk_fixed_factor_get_rate(struct clk *clk)
> +{
> + int ret;
> + struct clk_fixed_factor *ff = to_clk_fixed_factor(clk->dev);
> +
> + if (clk->id != 0)
> + return -EINVAL;
> +
> + ret = clk_get_rate(&ff->parent);
> + if (IS_ERR_VALUE(ret))
> + return ret;
> +
> + do_div(ret, ff->div);
> +
> + return ret * ff->mult;
> +}
> +
> +const struct clk_ops clk_fixed_factor_ops = {
> + .get_rate = clk_fixed_factor_get_rate,
> +};
> +
> +static int clk_fixed_factor_ofdata_to_platdata(struct udevice *dev)
> +{
> +#if !CONFIG_IS_ENABLED(OF_PLATDATA)

Why do you need this?

Alex

> + int err;
> + struct clk_fixed_factor *ff = to_clk_fixed_factor(dev);
> +
> + err = clk_get_by_index(dev, 0, &ff->parent);
> + if (err)
> + return err;
> +
> + ff->div = dev_read_u32_default(dev, "clock-div", 1);
> + ff->mult = dev_read_u32_default(dev, "clock-mult", 1);
> +#endif
> +
> + return 0;
> +}
> +
> +static const struct udevice_id clk_fixed_factor_match[] = {
> + {
> + .compatible = "fixed-factor-clock",
> + },
> + { /* sentinel */ }
> +};
> +
> +U_BOOT_DRIVER(clk_fixed_factor) = {
> + .name = "fixed_factor_clock",
> + .id = UCLASS_CLK,
> + .of_match = clk_fixed_factor_match,
> + .ofdata_to_platdata = clk_fixed_factor_ofdata_to_platdata,
> + .platdata_auto_alloc_size = sizeof(struct clk_fixed_factor),
> + .ops = &clk_fixed_factor_ops,
> +};