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Diffstat (limited to 'arch/arm/mach-zynq/slcr.c')
-rw-r--r--arch/arm/mach-zynq/slcr.c104
1 files changed, 89 insertions, 15 deletions
diff --git a/arch/arm/mach-zynq/slcr.c b/arch/arm/mach-zynq/slcr.c
index 1836d5a34606..a37d49a6e657 100644
--- a/arch/arm/mach-zynq/slcr.c
+++ b/arch/arm/mach-zynq/slcr.c
@@ -15,7 +15,9 @@
*/
#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"
@@ -29,7 +31,56 @@
#define SLCR_A9_CPU_CLKSTOP 0x10
#define SLCR_A9_CPU_RST 0x1
-void __iomem *zynq_slcr_base;
+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)
+{
+ if (!zynq_slcr_regmap) {
+ writel(val, zynq_slcr_base + offset);
+ return 0;
+ }
+
+ 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)
+{
+ if (zynq_slcr_regmap)
+ return regmap_read(zynq_slcr_regmap, offset, val);
+
+ *val = readl(zynq_slcr_base + offset);
+
+ return 0;
+}
+
+/**
+ * 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_system_reset - Reset the entire system.
@@ -43,16 +94,16 @@ void zynq_slcr_system_reset(void)
* 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);
+ 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.
*/
- 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_read(&reboot, SLCR_REBOOT_STATUS_OFFSET);
+ zynq_slcr_write(reboot & 0xF0FFFFFF, SLCR_REBOOT_STATUS_OFFSET);
+ zynq_slcr_write(1, SLCR_PS_RST_CTRL_OFFSET);
}
/**
@@ -61,11 +112,13 @@ void zynq_slcr_system_reset(void)
*/
void zynq_slcr_cpu_start(int cpu)
{
- u32 reg = readl(zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+ u32 reg;
+
+ zynq_slcr_read(&reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
reg &= ~(SLCR_A9_CPU_RST << cpu);
- writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+ zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
reg &= ~(SLCR_A9_CPU_CLKSTOP << cpu);
- writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+ zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
}
/**
@@ -74,19 +127,40 @@ void zynq_slcr_cpu_start(int cpu)
*/
void zynq_slcr_cpu_stop(int cpu)
{
- u32 reg = readl(zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+ u32 reg;
+
+ zynq_slcr_read(&reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
reg |= (SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu;
- writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+ zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
}
/**
- * zynq_slcr_init
- * Returns 0 on success, negative errno otherwise.
+ * zynq_slcr_init - Regular slcr driver init
+ *
+ * Return: 0 on success, negative errno otherwise.
*
* Called early during boot from platform code to remap SLCR area.
*/
int __init zynq_slcr_init(void)
{
+ 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;
+ }
+
+ return 0;
+}
+
+/**
+ * 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");
@@ -101,13 +175,13 @@ int __init zynq_slcr_init(void)
BUG();
}
+ np->data = (__force void *)zynq_slcr_base;
+
/* unlock the SLCR so that registers can be changed */
- writel(SLCR_UNLOCK_MAGIC, zynq_slcr_base + SLCR_UNLOCK_OFFSET);
+ zynq_slcr_unlock();
pr_info("%s mapped to %p\n", np->name, zynq_slcr_base);
- zynq_clock_init(zynq_slcr_base);
-
of_node_put(np);
return 0;