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Diffstat (limited to 'arch/arm/mach-zynq/slcr.c')
-rw-r--r--arch/arm/mach-zynq/slcr.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/arch/arm/mach-zynq/slcr.c b/arch/arm/mach-zynq/slcr.c
new file mode 100644
index 000000000000..c70969b9c258
--- /dev/null
+++ b/arch/arm/mach-zynq/slcr.c
@@ -0,0 +1,125 @@
+/*
+ * 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/export.h>
+#include <linux/io.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/uaccess.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/clk/zynq.h>
+#include "common.h"
+
+#define SLCR_UNLOCK_MAGIC 0xDF0D
+#define SLCR_UNLOCK 0x8 /* SCLR unlock register */
+
+#define SLCR_PS_RST_CTRL_OFFSET 0x200 /* PS Software Reset Control */
+
+#define SLCR_A9_CPU_CLKSTOP 0x10
+#define SLCR_A9_CPU_RST 0x1
+
+#define SLCR_A9_CPU_RST_CTRL 0x244 /* CPU Software Reset Control */
+#define SLCR_REBOOT_STATUS 0x258 /* PS Reboot Status */
+
+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);
+
+ /*
+ * 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);
+ writel(reboot & 0xF0FFFFFF, zynq_slcr_base + SLCR_REBOOT_STATUS);
+ 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);
+ /* enable CLK for CPUn */
+ writel(0x0 << cpu, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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);
+
+ pr_info("%s mapped to %p\n", np->name, zynq_slcr_base);
+
+ xilinx_zynq_clocks_init(zynq_slcr_base);
+
+ of_node_put(np);
+
+ return 0;
+}