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authorYuval Adam <_@yuv.al>2017-08-30 08:25:59 +0000
committerYuval Adam <_@yuv.al>2017-08-30 08:25:59 +0000
commit8e4bff4cab0ddac6060645b0715210484d02ff40 (patch)
tree3a5c3024371a04692a3a6d9974d001cdff8ebf84 /arch/arm/mach-prima2/rstc.c
Initial file dump from open source releaseHEADmaster
Diffstat (limited to 'arch/arm/mach-prima2/rstc.c')
-rw-r--r--arch/arm/mach-prima2/rstc.c90
1 files changed, 90 insertions, 0 deletions
diff --git a/arch/arm/mach-prima2/rstc.c b/arch/arm/mach-prima2/rstc.c
new file mode 100644
index 00000000..d5e0cbc9
--- /dev/null
+++ b/arch/arm/mach-prima2/rstc.c
@@ -0,0 +1,90 @@
+/*
+ * reset controller for CSR SiRFprimaII
+ *
+ * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+void __iomem *sirfsoc_rstc_base;
+static DEFINE_MUTEX(rstc_lock);
+
+static struct of_device_id rstc_ids[] = {
+ { .compatible = "sirf,prima2-rstc" },
+ { .compatible = "sirf,marco-rstc" },
+ {},
+};
+
+static int __init sirfsoc_of_rstc_init(void)
+{
+ struct device_node *np;
+
+ np = of_find_matching_node(NULL, rstc_ids);
+ if (!np) {
+ pr_err("unable to find compatible sirf rstc node in dtb\n");
+ return -ENOENT;
+ }
+
+ sirfsoc_rstc_base = of_iomap(np, 0);
+ if (!sirfsoc_rstc_base)
+ panic("unable to map rstc cpu registers\n");
+
+ of_node_put(np);
+
+ return 0;
+}
+early_initcall(sirfsoc_of_rstc_init);
+
+int sirfsoc_reset_device(struct device *dev)
+{
+ u32 reset_bit;
+
+ if (of_property_read_u32(dev->of_node, "reset-bit", &reset_bit))
+ return -EINVAL;
+
+ mutex_lock(&rstc_lock);
+
+ if (of_device_is_compatible(dev->of_node, "sirf,prima2-rstc")) {
+ /*
+ * Writing 1 to this bit resets corresponding block. Writing 0 to this
+ * bit de-asserts reset signal of the corresponding block.
+ * datasheet doesn't require explicit delay between the set and clear
+ * of reset bit. it could be shorter if tests pass.
+ */
+ writel(readl(sirfsoc_rstc_base + (reset_bit / 32) * 4) | reset_bit,
+ sirfsoc_rstc_base + (reset_bit / 32) * 4);
+ msleep(10);
+ writel(readl(sirfsoc_rstc_base + (reset_bit / 32) * 4) & ~reset_bit,
+ sirfsoc_rstc_base + (reset_bit / 32) * 4);
+ } else {
+ /*
+ * For MARCO and POLO
+ * Writing 1 to SET register resets corresponding block. Writing 1 to CLEAR
+ * register de-asserts reset signal of the corresponding block.
+ * datasheet doesn't require explicit delay between the set and clear
+ * of reset bit. it could be shorter if tests pass.
+ */
+ writel(reset_bit, sirfsoc_rstc_base + (reset_bit / 32) * 8);
+ msleep(10);
+ writel(reset_bit, sirfsoc_rstc_base + (reset_bit / 32) * 8 + 4);
+ }
+
+ mutex_unlock(&rstc_lock);
+
+ return 0;
+}
+
+#define SIRFSOC_SYS_RST_BIT BIT(31)
+
+void sirfsoc_restart(char mode, const char *cmd)
+{
+ writel(SIRFSOC_SYS_RST_BIT, sirfsoc_rstc_base);
+}