clk: ti: add support for TI fixed factor clock

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], and also uses the autoidle

support from TI autoidle clock [2].

[1] Documentation/devicetree/bindings/clock/clock-bindings.txt

[2] Documentation/devicetree/bindings/clock/ti/autoidle.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,

  see [2]

- reg: offset for the autoidle register of this clock, see [2]

- ti,invert-autoidle-bit: autoidle is enabled by setting the bit to 0, see [2]

- 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>;

	};

	dpll_usb_clkdcoldo_ck: dpll_usb_clkdcoldo_ck {

		#clock-cells = <0>;

		compatible = "ti,fixed-factor-clock";

		clocks = <&dpll_usb_ck>;

		ti,clock-div = <1>;

		ti,autoidle-shift = <8>;

		reg = <0x01b4>;

		ti,clock-mult = <1>;

		ti,invert-autoidle-bit;

	};

ifneq ($(CONFIG_OF),)

obj-y					+= clk.o autoidle.o

clk-common				= dpll.o composite.o divider.o

clk-common				= dpll.o composite.o divider.o \

					  fixed-factor.o

endif

/*

 * 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>

#undef pr_fmt

#define pr_fmt(fmt) "%s: " fmt, __func__

/**

 * of_ti_fixed_factor_clk_setup - Setup function for TI fixed factor clock

 * @node: device node for this clock

 *

 * Sets up a simple fixed factor clock based on device tree info.

 */

static void __init of_ti_fixed_factor_clk_setup(struct device_node *node)

{

	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 must have a clock-div property\n", node->name);

		return;

	}

	if (of_property_read_u32(node, "ti,clock-mult", &mult)) {

		pr_err("%s must have a clock-mult property\n", node->name);

		return;

	}

	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);

		of_ti_clk_autoidle_setup(node);

	}

}

CLK_OF_DECLARE(ti_fixed_factor_clk, "ti,fixed-factor-clock",

	       of_ti_fixed_factor_clk_setup);