Re: [PATCHv9 10/43] clk: ti: add support for TI fixed factor clock

[Nishanth Menon <nm@ti.com>]

On 10/25/2013 10:57 AM, Tero Kristo wrote:
> This behaves exactly in similar manner to basic fixed-factor-clock, but
> adds a few properties on top for handling clock hardware autoidling.
> 
> Signed-off-by: Tero Kristo <t-kristo@ti.com>
> ---
>  .../bindings/clock/ti/fixed-factor-clock.txt       |   29 +++++++++
>  drivers/clk/ti/Makefile                            |    2 +-
>  drivers/clk/ti/fixed-factor.c                      |   65 ++++++++++++++++++++
>  3 files changed, 95 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt
>  create mode 100644 drivers/clk/ti/fixed-factor.c
> 
> diff --git a/Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt b/Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt
> new file mode 100644
> index 0000000..60b9e34
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt
> @@ -0,0 +1,29 @@
> +Binding for TI fixed factor rate clock sources.
> +
> +Binding status: Unstable - ABI compatibility may be broken in the future
> +
> +This binding uses the common clock binding[1].
> +
> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
> +
> +Required properties:
> +- compatible : shall be "ti,fixed-factor-clock".
> +- #clock-cells : from common clock binding; shall be set to 0.
> +- ti,clock-div: fixed divider.
> +- ti,clock-mult: fixed multiplier.
> +- clocks: parent clock.
> +
> +Optional properties:
> +- ti,autoidle-shift: bit shift of the autoidle enable bit for the clock
> +- reg: offset for the autoidle register of this clock
> +- ti,invert-autoidle-bit: autoidle is enabled by setting the bit to 0

The above three belong to autoidle stuff I think.. maybe pointing to
it's binding will help?

> +- ti,set-rate-parent: clk_set_rate is propagated to parent
> +
> +Example:
> +	clock {
> +		compatible = "ti,fixed-factor-clock";
> +		clocks = <&parentclk>;
> +		#clock-cells = <0>;
> +		ti,clock-div = <2>;
> +		ti,clock-mult = <1>;
> +	};
> diff --git a/drivers/clk/ti/Makefile b/drivers/clk/ti/Makefile
> index 640ebf9..f57fc4b 100644
> --- a/drivers/clk/ti/Makefile
> +++ b/drivers/clk/ti/Makefile
> @@ -1,4 +1,4 @@
>  ifneq ($(CONFIG_OF),)
>  obj-y					+= clk.o dpll.o autoidle.o divider.o \
> -					   composite.o
> +					   fixed-factor.o composite.o
>  endif
> diff --git a/drivers/clk/ti/fixed-factor.c b/drivers/clk/ti/fixed-factor.c
> new file mode 100644
> index 0000000..e0549c6
> --- /dev/null
> +++ b/drivers/clk/ti/fixed-factor.c
> @@ -0,0 +1,65 @@
> +/*
> + * TI Fixed Factor Clock
> + *
> + * Copyright (C) 2013 Texas Instruments, Inc.
> + *
> + * Tero Kristo <t-kristo@ti.com>
> + *
> + * 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 "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether express or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/slab.h>
> +#include <linux/err.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/clk/ti.h>
> +
> +/**
> + * of_ti_fixed_factor_clk_setup() - Setup function for TI fixed factor clock
> + */
> +static int __init of_ti_fixed_factor_clk_setup(struct device_node *node,
> +					       struct regmap *regmap)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	const char *parent_name;
> +	u32 div, mult;
> +	u32 flags = 0;
> +
> +	if (of_property_read_u32(node, "ti,clock-div", &div)) {
> +		pr_err("%s Fixed factor clock <%s> must have a clock-div property\n",
> +		       __func__, node->name);
> +		return -EINVAL;
> +	}
> +
> +	if (of_property_read_u32(node, "ti,clock-mult", &mult)) {
> +		pr_err("%s Fixed factor clock <%s> must have a clokc-mult property\n",
> +		       __func__, node->name);
> +		return -EINVAL;
> +	}
> +
> +	if (of_property_read_bool(node, "ti,set-rate-parent"))
> +		flags |= CLK_SET_RATE_PARENT;
> +
> +	parent_name = of_clk_get_parent_name(node, 0);
> +
> +	clk = clk_register_fixed_factor(NULL, clk_name, parent_name, flags,
> +					mult, div);
> +
> +	if (!IS_ERR(clk)) {
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +		return of_ti_autoidle_setup(node, regmap);

if this fails, remove provider and unregister?

> +	}
> +
> +	return PTR_ERR(clk);
> +}
> +CLK_OF_DECLARE(ti_fixed_factor_clk, "ti,fixed-factor-clock",
> +	       of_ti_fixed_factor_clk_setup);
> 


-- 
Regards,
Nishanth Menon