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path: root/drivers/soc/brcmstb/biuctrl.c
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Diffstat (limited to 'drivers/soc/brcmstb/biuctrl.c')
-rw-r--r--drivers/soc/brcmstb/biuctrl.c116
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 000000000..9049c076f
--- /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
+}