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-rw-r--r--arch/arm/mach-zynq/slcr.c233
1 files changed, 233 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..9765b3f4c
--- /dev/null
+++ b/arch/arm/mach-zynq/slcr.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Xilinx SLCR driver
+ *
+ * Copyright (c) 2011-2013 Xilinx Inc.
+ */
+
+#include <linux/io.h>
+#include <linux/reboot.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_L2C_RAM 0xA1C /* L2C_RAM in AR#54190 */
+
+#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_restart - Restart the entire system.
+ *
+ * @nb: Pointer to restart notifier block (unused)
+ * @action: Reboot mode (unused)
+ * @data: Restart handler private data (unused)
+ *
+ * Return: 0 always
+ */
+static
+int zynq_slcr_system_restart(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ u32 reboot;
+
+ /*
+ * 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);
+ return 0;
+}
+
+static struct notifier_block zynq_slcr_restart_nb = {
+ .notifier_call = zynq_slcr_system_restart,
+ .priority = 192,
+};
+
+/**
+ * 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__);
+ of_node_put(np);
+ return -ENODEV;
+ }
+
+ /* unlock the SLCR so that registers can be changed */
+ zynq_slcr_unlock();
+
+ /* See AR#54190 design advisory */
+ regmap_update_bits(zynq_slcr_regmap, SLCR_L2C_RAM, 0x70707, 0x20202);
+
+ register_restart_handler(&zynq_slcr_restart_nb);
+
+ pr_info("%pOFn mapped to %p\n", np, zynq_slcr_base);
+
+ of_node_put(np);
+
+ return 0;
+}