Initial import

1 files changed, 227 insertions, 0 deletions

diff --git a/arch/arm/mach-zynq/slcr.c b/arch/arm/mach-zynq/slcr.c
new file mode 100644
index 000000000..c3c24fd8b
--- /dev/null
+++ b/arch/arm/mach-zynq/slcr.c
@@ -0,0 +1,227 @@
+/*
+ * 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/mfd/syscon.h>
+#include <linux/of_address.h>
+#include <linux/regmap.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_PSS_IDCODE			0x530 /* PS IDCODE */
+
+#define SLCR_UNLOCK_MAGIC		0xDF0D
+#define SLCR_A9_CPU_CLKSTOP		0x10
+#define SLCR_A9_CPU_RST			0x1
+#define SLCR_PSS_IDCODE_DEVICE_SHIFT	12
+#define SLCR_PSS_IDCODE_DEVICE_MASK	0x1F
+
+static void __iomem *zynq_slcr_base;
+static struct regmap *zynq_slcr_regmap;
+
+/**
+ * zynq_slcr_write - Write to a register in SLCR block
+ *
+ * @val:	Value to write to the register
+ * @offset:	Register offset in SLCR block
+ *
+ * Return:	a negative value on error, 0 on success
+ */
+static int zynq_slcr_write(u32 val, u32 offset)
+{
+	return regmap_write(zynq_slcr_regmap, offset, val);
+}
+
+/**
+ * zynq_slcr_read - Read a register in SLCR block
+ *
+ * @val:	Pointer to value to be read from SLCR
+ * @offset:	Register offset in SLCR block
+ *
+ * Return:	a negative value on error, 0 on success
+ */
+static int zynq_slcr_read(u32 *val, u32 offset)
+{
+	return regmap_read(zynq_slcr_regmap, offset, val);
+}
+
+/**
+ * zynq_slcr_unlock - Unlock SLCR registers
+ *
+ * Return:	a negative value on error, 0 on success
+ */
+static inline int zynq_slcr_unlock(void)
+{
+	zynq_slcr_write(SLCR_UNLOCK_MAGIC, SLCR_UNLOCK_OFFSET);
+
+	return 0;
+}
+
+/**
+ * zynq_slcr_get_device_id - Read device code id
+ *
+ * Return:	Device code id
+ */
+u32 zynq_slcr_get_device_id(void)
+{
+	u32 val;
+
+	zynq_slcr_read(&val, SLCR_PSS_IDCODE);
+	val >>= SLCR_PSS_IDCODE_DEVICE_SHIFT;
+	val &= SLCR_PSS_IDCODE_DEVICE_MASK;
+
+	return val;
+}
+
+/**
+ * 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?
+	 */
+	zynq_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.
+	 */
+	zynq_slcr_read(&reboot, SLCR_REBOOT_STATUS_OFFSET);
+	zynq_slcr_write(reboot & 0xF0FFFFFF, SLCR_REBOOT_STATUS_OFFSET);
+	zynq_slcr_write(1, SLCR_PS_RST_CTRL_OFFSET);
+}
+
+/**
+ * zynq_slcr_cpu_start - Start cpu
+ * @cpu:	cpu number
+ */
+void zynq_slcr_cpu_start(int cpu)
+{
+	u32 reg;
+
+	zynq_slcr_read(&reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
+	reg &= ~(SLCR_A9_CPU_RST << cpu);
+	zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
+	reg &= ~(SLCR_A9_CPU_CLKSTOP << cpu);
+	zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
+
+	zynq_slcr_cpu_state_write(cpu, false);
+}
+
+/**
+ * zynq_slcr_cpu_stop - Stop cpu
+ * @cpu:	cpu number
+ */
+void zynq_slcr_cpu_stop(int cpu)
+{
+	u32 reg;
+
+	zynq_slcr_read(&reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
+	reg |= (SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu;
+	zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
+}
+
+/**
+ * zynq_slcr_cpu_state - Read/write cpu state
+ * @cpu:	cpu number
+ *
+ * SLCR_REBOOT_STATUS save upper 2 bits (31/30 cpu states for cpu0 and cpu1)
+ * 0 means cpu is running, 1 cpu is going to die.
+ *
+ * Return: true if cpu is running, false if cpu is going to die
+ */
+bool zynq_slcr_cpu_state_read(int cpu)
+{
+	u32 state;
+
+	state = readl(zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
+	state &= 1 << (31 - cpu);
+
+	return !state;
+}
+
+/**
+ * zynq_slcr_cpu_state - Read/write cpu state
+ * @cpu:	cpu number
+ * @die:	cpu state - true if cpu is going to die
+ *
+ * SLCR_REBOOT_STATUS save upper 2 bits (31/30 cpu states for cpu0 and cpu1)
+ * 0 means cpu is running, 1 cpu is going to die.
+ */
+void zynq_slcr_cpu_state_write(int cpu, bool die)
+{
+	u32 state, mask;
+
+	state = readl(zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
+	mask = 1 << (31 - cpu);
+	if (die)
+		state |= mask;
+	else
+		state &= ~mask;
+	writel(state, zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
+}
+
+/**
+ * zynq_early_slcr_init - Early slcr init function
+ *
+ * Return:	0 on success, negative errno otherwise.
+ *
+ * Called very early during boot from platform code to unlock SLCR.
+ */
+int __init zynq_early_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();
+	}
+
+	np->data = (__force void *)zynq_slcr_base;
+
+	zynq_slcr_regmap = syscon_regmap_lookup_by_compatible("xlnx,zynq-slcr");
+	if (IS_ERR(zynq_slcr_regmap)) {
+		pr_err("%s: failed to find zynq-slcr\n", __func__);
+		return -ENODEV;
+	}
+
+	/* unlock the SLCR so that registers can be changed */
+	zynq_slcr_unlock();
+
+	pr_info("%s mapped to %p\n", np->name, zynq_slcr_base);
+
+	of_node_put(np);
+
+	return 0;
+}