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

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@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,

+};