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Commit 96e4ea8c authored by Codrin Ciubotariu's avatar Codrin Ciubotariu Committed by Stephen Boyd
Browse files

clk: at91: add I2S clock mux driver 



This driver is a simple muxing driver that controls the
I2S's clock input by using syscon/regmap to change the parent.
The available inputs can be peripheral clock and generated clock.

Signed-off-by: default avatarCodrin Ciubotariu <codrin.ciubotariu@microchip.com>
[sboyd@kernel.org: Fix SPDX tag comment style]
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent 5f273c0d

arch/arm/mach-at91/Kconfig

+4 −0
Original line number Original line Diff line number Diff line
@@ -27,6 +27,7 @@ config SOC_SAMA5D2 
	select HAVE_AT91_H32MX

	select HAVE_AT91_H32MX

	select HAVE_AT91_GENERATED_CLK

	select HAVE_AT91_GENERATED_CLK

	select HAVE_AT91_AUDIO_PLL

	select HAVE_AT91_AUDIO_PLL

	select HAVE_AT91_I2S_MUX_CLK

	select PINCTRL_AT91PIO4

	select PINCTRL_AT91PIO4

	help

	help

	  Select this if ou are using one of Microchip's SAMA5D2 family SoC.

	  Select this if ou are using one of Microchip's SAMA5D2 family SoC.
@@ -129,6 +130,9 @@ config HAVE_AT91_GENERATED_CLK 
config HAVE_AT91_AUDIO_PLL

config HAVE_AT91_AUDIO_PLL

	bool

	bool





config HAVE_AT91_I2S_MUX_CLK

	bool



config SOC_SAM_V4_V5

config SOC_SAM_V4_V5

	bool

	bool

drivers/clk/at91/Makefile

+1 −0
Original line number Original line Diff line number Diff line
@@ -13,3 +13,4 @@ obj-$(CONFIG_HAVE_AT91_USB_CLK) += clk-usb.o 
obj-$(CONFIG_HAVE_AT91_SMD)		+= clk-smd.o

obj-$(CONFIG_HAVE_AT91_SMD)		+= clk-smd.o

obj-$(CONFIG_HAVE_AT91_H32MX)		+= clk-h32mx.o

obj-$(CONFIG_HAVE_AT91_H32MX)		+= clk-h32mx.o

obj-$(CONFIG_HAVE_AT91_GENERATED_CLK)	+= clk-generated.o

obj-$(CONFIG_HAVE_AT91_GENERATED_CLK)	+= clk-generated.o

obj-$(CONFIG_HAVE_AT91_I2S_MUX_CLK)	+= clk-i2s-mux.o

drivers/clk/at91/clk-i2s-mux.c

0 → 100644
+116 −0
Original line number Original line Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 *  Copyright (C) 2018 Microchip Technology Inc,

 *                     Codrin Ciubotariu <codrin.ciubotariu@microchip.com>

 *

 *

 */



#include <linux/clk-provider.h>

#include <linux/of.h>

#include <linux/mfd/syscon.h>

#include <linux/regmap.h>

#include <linux/slab.h>



#include <soc/at91/atmel-sfr.h>



#define	I2S_BUS_NR	2



struct clk_i2s_mux {

	struct clk_hw hw;

	struct regmap *regmap;

	u8 bus_id;

};



#define to_clk_i2s_mux(hw) container_of(hw, struct clk_i2s_mux, hw)



static u8 clk_i2s_mux_get_parent(struct clk_hw *hw)

{

	struct clk_i2s_mux *mux = to_clk_i2s_mux(hw);

	u32 val;



	regmap_read(mux->regmap, AT91_SFR_I2SCLKSEL, &val);



	return (val & BIT(mux->bus_id)) >> mux->bus_id;

}



static int clk_i2s_mux_set_parent(struct clk_hw *hw, u8 index)

{

	struct clk_i2s_mux *mux = to_clk_i2s_mux(hw);



	return regmap_update_bits(mux->regmap, AT91_SFR_I2SCLKSEL,

				  BIT(mux->bus_id), index << mux->bus_id);

}



static const struct clk_ops clk_i2s_mux_ops = {

	.get_parent = clk_i2s_mux_get_parent,

	.set_parent = clk_i2s_mux_set_parent,

	.determine_rate = __clk_mux_determine_rate,

};



static struct clk_hw * __init

at91_clk_i2s_mux_register(struct regmap *regmap, const char *name,

			  const char * const *parent_names,

			  unsigned int num_parents, u8 bus_id)

{

	struct clk_init_data init = {};

	struct clk_i2s_mux *i2s_ck;

	int ret;



	i2s_ck = kzalloc(sizeof(*i2s_ck), GFP_KERNEL);

	if (!i2s_ck)

		return ERR_PTR(-ENOMEM);



	init.name = name;

	init.ops = &clk_i2s_mux_ops;

	init.parent_names = parent_names;

	init.num_parents = num_parents;



	i2s_ck->hw.init = &init;

	i2s_ck->bus_id = bus_id;

	i2s_ck->regmap = regmap;



	ret = clk_hw_register(NULL, &i2s_ck->hw);

	if (ret) {

		kfree(i2s_ck);

		return ERR_PTR(ret);

	}



	return &i2s_ck->hw;

}



static void __init of_sama5d2_clk_i2s_mux_setup(struct device_node *np)

{

	struct regmap *regmap_sfr;

	u8 bus_id;

	const char *parent_names[2];

	struct device_node *i2s_mux_np;

	struct clk_hw *hw;

	int ret;



	regmap_sfr = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr");

	if (IS_ERR(regmap_sfr))

		return;



	for_each_child_of_node(np, i2s_mux_np) {

		if (of_property_read_u8(i2s_mux_np, "reg", &bus_id))

			continue;



		if (bus_id > I2S_BUS_NR)

			continue;



		ret = of_clk_parent_fill(i2s_mux_np, parent_names, 2);

		if (ret != 2)

			continue;



		hw = at91_clk_i2s_mux_register(regmap_sfr, i2s_mux_np->name,

					       parent_names, 2, bus_id);

		if (IS_ERR(hw))

			continue;



		of_clk_add_hw_provider(i2s_mux_np, of_clk_hw_simple_get, hw);

	}

}



CLK_OF_DECLARE(sama5d2_clk_i2s_mux, "atmel,sama5d2-clk-i2s-mux",

	       of_sama5d2_clk_i2s_mux_setup);