1 files changed, 116 insertions, 0 deletions
diff --git a/drivers/soc/brcmstb/biuctrl.c b/drivers/soc/brcmstb/biuctrl.c
new file mode 100644
index 000000000000..9049c076f9a1
--- /dev/null
+++ b/drivers/soc/brcmstb/biuctrl.c
@@ -0,0 +1,116 @@
+/*
+ * Broadcom STB SoCs Bus Unit Interface controls
+ *
+ * Copyright (C) 2015, Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt)	"brcmstb: " KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/syscore_ops.h>
+
+#define CPU_CREDIT_REG_OFFSET			0x184
+#define  CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK	0x70000000
+
+static void __iomem *cpubiuctrl_base;
+static bool mcp_wr_pairing_en;
+
+static int __init mcp_write_pairing_set(void)
+{
+	u32 creds = 0;
+
+	if (!cpubiuctrl_base)
+		return -1;
+
+	creds = readl_relaxed(cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
+	if (mcp_wr_pairing_en) {
+		pr_info("MCP: Enabling write pairing\n");
+		writel_relaxed(creds | CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK,
+			     cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
+	} else if (creds & CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK) {
+		pr_info("MCP: Disabling write pairing\n");
+		writel_relaxed(creds & ~CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK,
+				cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
+	} else {
+		pr_info("MCP: Write pairing already disabled\n");
+	}
+
+	return 0;
+}
+
+static int __init setup_hifcpubiuctrl_regs(void)
+{
+	struct device_node *np;
+	int ret = 0;
+
+	np = of_find_compatible_node(NULL, NULL, "brcm,brcmstb-cpu-biu-ctrl");
+	if (!np) {
+		pr_err("missing BIU control node\n");
+		return -ENODEV;
+	}
+
+	cpubiuctrl_base = of_iomap(np, 0);
+	if (!cpubiuctrl_base) {
+		pr_err("failed to remap BIU control base\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	mcp_wr_pairing_en = of_property_read_bool(np, "brcm,write-pairing");
+out:
+	of_node_put(np);
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static u32 cpu_credit_reg_dump;  /* for save/restore */
+
+static int brcmstb_cpu_credit_reg_suspend(void)
+{
+	if (cpubiuctrl_base)
+		cpu_credit_reg_dump =
+			readl_relaxed(cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
+	return 0;
+}
+
+static void brcmstb_cpu_credit_reg_resume(void)
+{
+	if (cpubiuctrl_base)
+		writel_relaxed(cpu_credit_reg_dump,
+				cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
+}
+
+static struct syscore_ops brcmstb_cpu_credit_syscore_ops = {
+	.suspend = brcmstb_cpu_credit_reg_suspend,
+	.resume = brcmstb_cpu_credit_reg_resume,
+};
+#endif
+
+
+void __init brcmstb_biuctrl_init(void)
+{
+	int ret;
+
+	setup_hifcpubiuctrl_regs();
+
+	ret = mcp_write_pairing_set();
+	if (ret) {
+		pr_err("MCP: Unable to disable write pairing!\n");
+		return;
+	}
+
+#ifdef CONFIG_PM_SLEEP
+	register_syscore_ops(&brcmstb_cpu_credit_syscore_ops);
+#endif
+}