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-rw-r--r--kernel/arch/arm/mach-zynq/slcr.c227
1 files changed, 227 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-zynq/slcr.c b/kernel/arch/arm/mach-zynq/slcr.c
new file mode 100644
index 000000000..c3c24fd8b
--- /dev/null
+++ b/kernel/arch/arm/mach-zynq/slcr.c
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+/*
+ * 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;
+}