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linux-next/arch/arm/mach-zynq/slcr.c
Soren Brinkmann b5f177ff30 arm: zynq: slcr: Clean up #defines
Use a common naming scheme for register offset #defines:
Some of those used a '_OFFSET' suffix to distinguish them from others.
This scheme is used for all register offsets now.

Separate the register offset #defines from others and sort them in
increasing order.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2013-07-26 14:14:39 +02:00

115 lines
2.9 KiB
C

/*
* Xilinx SLCR driver
*
* Copyright (c) 2011-2013 Xilinx Inc.
*
* 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.
*
* 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., 675 Mass Ave, Cambridge, MA
* 02139, USA.
*/
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/clk/zynq.h>
#include "common.h"
/* register offsets */
#define SLCR_UNLOCK_OFFSET 0x8 /* SCLR unlock register */
#define SLCR_PS_RST_CTRL_OFFSET 0x200 /* PS Software Reset Control */
#define SLCR_A9_CPU_RST_CTRL_OFFSET 0x244 /* CPU Software Reset Control */
#define SLCR_REBOOT_STATUS_OFFSET 0x258 /* PS Reboot Status */
#define SLCR_UNLOCK_MAGIC 0xDF0D
#define SLCR_A9_CPU_CLKSTOP 0x10
#define SLCR_A9_CPU_RST 0x1
void __iomem *zynq_slcr_base;
/**
* zynq_slcr_system_reset - Reset the entire system.
*/
void zynq_slcr_system_reset(void)
{
u32 reboot;
/*
* Unlock the SLCR then reset the system.
* Note that this seems to require raw i/o
* functions or there's a lockup?
*/
writel(SLCR_UNLOCK_MAGIC, zynq_slcr_base + SLCR_UNLOCK_OFFSET);
/*
* Clear 0x0F000000 bits of reboot status register to workaround
* the FSBL not loading the bitstream after soft-reboot
* This is a temporary solution until we know more.
*/
reboot = readl(zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
writel(reboot & 0xF0FFFFFF, zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
writel(1, zynq_slcr_base + SLCR_PS_RST_CTRL_OFFSET);
}
/**
* zynq_slcr_cpu_start - Start cpu
* @cpu: cpu number
*/
void zynq_slcr_cpu_start(int cpu)
{
/* enable CPUn */
writel(SLCR_A9_CPU_CLKSTOP << cpu,
zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
/* enable CLK for CPUn */
writel(0x0 << cpu, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
}
/**
* zynq_slcr_cpu_stop - Stop cpu
* @cpu: cpu number
*/
void zynq_slcr_cpu_stop(int cpu)
{
/* stop CLK and reset CPUn */
writel((SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu,
zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
}
/**
* zynq_slcr_init
* Returns 0 on success, negative errno otherwise.
*
* Called early during boot from platform code to remap SLCR area.
*/
int __init zynq_slcr_init(void)
{
struct device_node *np;
np = of_find_compatible_node(NULL, NULL, "xlnx,zynq-slcr");
if (!np) {
pr_err("%s: no slcr node found\n", __func__);
BUG();
}
zynq_slcr_base = of_iomap(np, 0);
if (!zynq_slcr_base) {
pr_err("%s: Unable to map I/O memory\n", __func__);
BUG();
}
/* unlock the SLCR so that registers can be changed */
writel(SLCR_UNLOCK_MAGIC, zynq_slcr_base + SLCR_UNLOCK_OFFSET);
pr_info("%s mapped to %p\n", np->name, zynq_slcr_base);
zynq_clock_init(zynq_slcr_base);
of_node_put(np);
return 0;
}