Commit 75fabc3f authored by Simon Arlott's avatar Simon Arlott Committed by Stephen Warren
Browse files

ARM: bcm2835: add stub clock driver 

This patch adds a minimal stub clock driver for the BCM2835. Its sole
purpose is to allow the PL011 AMBA clk_get() API calls to provide
something that looks enough like a clock that the driver probes and
operates correctly.

This patch was extracted from git://github.com/lp0/linux.git

 branch
rpi-split as of 2012/09/08, and modified as follows:

* Reworked to call clk_register_fixed_rate(), and clk_register_clkdev()
  rather than using static data to represent the clocks.
* Moved implementation to drivers/clk/.
* Modified .dev_id for UART clocks to match UART DT node names.
* s/bcm2708/bcm2835/.
* Modified device tree vendor prefix.

Signed-off-by: default avatarChris Boot <bootc@bootc.net>
Signed-off-by: default avatarSimon Arlott <simon@fire.lp0.eu>
Signed-off-by: default avatarDom Cobley <popcornmix@gmail.com>
Signed-off-by: default avatarDom Cobley <dc4@broadcom.com>
Signed-off-by: default avatarStephen Warren <swarren@wwwdotorg.org>
Acked-by: default avatarMike Turquette <mturquette@linaro.org>
parent ee4af569

arch/arm/mach-bcm2835/bcm2835.c

+3 −0
Original line number Original line Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/irqchip/bcm2835.h>

#include <linux/irqchip/bcm2835.h>

#include <linux/of_platform.h>

#include <linux/of_platform.h>

#include <linux/bcm2835_timer.h>

#include <linux/bcm2835_timer.h>

#include <linux/clk/bcm2835.h>





#include <asm/mach/arch.h>

#include <asm/mach/arch.h>

#include <asm/mach/map.h>

#include <asm/mach/map.h>
@@ -38,6 +39,8 @@ void __init bcm2835_init(void) 
{

{

	int ret;

	int ret;





	bcm2835_init_clocks();



	ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,

	ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,

				   NULL);

				   NULL);

	if (ret) {

	if (ret) {

drivers/clk/Makefile

+1 −0
Original line number Original line Diff line number Diff line
@@ -3,6 +3,7 @@ obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o 
obj-$(CONFIG_COMMON_CLK)	+= clk.o clk-fixed-rate.o clk-gate.o \

obj-$(CONFIG_COMMON_CLK)	+= clk.o clk-fixed-rate.o clk-gate.o \

				   clk-mux.o clk-divider.o clk-fixed-factor.o

				   clk-mux.o clk-divider.o clk-fixed-factor.o

# SoCs specific

# SoCs specific

obj-$(CONFIG_ARCH_BCM2835)	+= clk-bcm2835.o

obj-$(CONFIG_ARCH_NOMADIK)	+= clk-nomadik.o

obj-$(CONFIG_ARCH_NOMADIK)	+= clk-nomadik.o

obj-$(CONFIG_ARCH_HIGHBANK)	+= clk-highbank.o

obj-$(CONFIG_ARCH_HIGHBANK)	+= clk-highbank.o

obj-$(CONFIG_ARCH_MXS)		+= mxs/

obj-$(CONFIG_ARCH_MXS)		+= mxs/

drivers/clk/clk-bcm2835.c

0 → 100644
+59 −0
Original line number Original line Diff line number Diff line 
/*

 * Copyright (C) 2010 Broadcom

 * Copyright (C) 2012 Stephen Warren

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */



#include <linux/clk-provider.h>

#include <linux/clkdev.h>

#include <linux/clk/bcm2835.h>



/*

 * These are fixed clocks. They're probably not all root clocks and it may

 * be possible to turn them on and off but until this is mapped out better

 * it's the only way they can be used.

 */

void __init bcm2835_init_clocks(void)

{

	struct clk *clk;

	int ret;



	clk = clk_register_fixed_rate(NULL, "sys_pclk", NULL, CLK_IS_ROOT,

					250000000);

	if (!clk)

		pr_err("sys_pclk not registered\n");



	clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, CLK_IS_ROOT,

					126000000);

	if (!clk)

		pr_err("apb_pclk not registered\n");



	clk = clk_register_fixed_rate(NULL, "uart0_pclk", NULL, CLK_IS_ROOT,

					3000000);

	if (!clk)

		pr_err("uart0_pclk not registered\n");

	ret = clk_register_clkdev(clk, NULL, "20201000.uart");

	if (ret)

		pr_err("uart0_pclk alias not registered\n");



	clk = clk_register_fixed_rate(NULL, "uart1_pclk", NULL, CLK_IS_ROOT,

					125000000);

	if (!clk)

		pr_err("uart1_pclk not registered\n");

	ret = clk_register_clkdev(clk, NULL, "20215000.uart");

	if (ret)

		pr_err("uart0_pclk alias not registered\n");

}

include/linux/clk/bcm2835.h

0 → 100644
+24 −0
Original line number Original line Diff line number Diff line 
/*

 * Copyright (C) 2010 Broadcom

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */



#ifndef __LINUX_CLK_BCM2835_H_

#define __LINUX_CLK_BCM2835_H_



void __init bcm2835_init_clocks(void);



#endif

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