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-rw-r--r--drivers/soc/gemini/soc-gemini.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/soc/gemini/soc-gemini.c b/drivers/soc/gemini/soc-gemini.c
new file mode 100644
index 000000000..642b96c91
--- /dev/null
+++ b/drivers/soc/gemini/soc-gemini.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 Linaro Ltd.
+ *
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * 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.
+ *
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+
+#define GLOBAL_WORD_ID 0x00
+#define GEMINI_GLOBAL_ARB1_CTRL 0x2c
+#define GEMINI_ARB1_BURST_MASK GENMASK(21, 16)
+#define GEMINI_ARB1_BURST_SHIFT 16
+/* These all define the priority on the BUS2 backplane */
+#define GEMINI_ARB1_PRIO_MASK GENMASK(9, 0)
+#define GEMINI_ARB1_DMAC_HIGH_PRIO BIT(0)
+#define GEMINI_ARB1_IDE_HIGH_PRIO BIT(1)
+#define GEMINI_ARB1_RAID_HIGH_PRIO BIT(2)
+#define GEMINI_ARB1_SECURITY_HIGH_PRIO BIT(3)
+#define GEMINI_ARB1_GMAC0_HIGH_PRIO BIT(4)
+#define GEMINI_ARB1_GMAC1_HIGH_PRIO BIT(5)
+#define GEMINI_ARB1_USB0_HIGH_PRIO BIT(6)
+#define GEMINI_ARB1_USB1_HIGH_PRIO BIT(7)
+#define GEMINI_ARB1_PCI_HIGH_PRIO BIT(8)
+#define GEMINI_ARB1_TVE_HIGH_PRIO BIT(9)
+
+#define GEMINI_DEFAULT_BURST_SIZE 0x20
+#define GEMINI_DEFAULT_PRIO (GEMINI_ARB1_GMAC0_HIGH_PRIO | \
+ GEMINI_ARB1_GMAC1_HIGH_PRIO)
+
+static int __init gemini_soc_init(void)
+{
+ struct regmap *map;
+ u32 rev;
+ u32 val;
+ int ret;
+
+ /* Multiplatform guard, only proceed on Gemini */
+ if (!of_machine_is_compatible("cortina,gemini"))
+ return 0;
+
+ map = syscon_regmap_lookup_by_compatible("cortina,gemini-syscon");
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+ ret = regmap_read(map, GLOBAL_WORD_ID, &rev);
+ if (ret)
+ return ret;
+
+ val = (GEMINI_DEFAULT_BURST_SIZE << GEMINI_ARB1_BURST_SHIFT) |
+ GEMINI_DEFAULT_PRIO;
+
+ /* Set up system arbitration */
+ regmap_update_bits(map,
+ GEMINI_GLOBAL_ARB1_CTRL,
+ GEMINI_ARB1_BURST_MASK | GEMINI_ARB1_PRIO_MASK,
+ val);
+
+ pr_info("Gemini SoC %04x revision %02x, set arbitration %08x\n",
+ rev >> 8, rev & 0xff, val);
+
+ return 0;
+}
+subsys_initcall(gemini_soc_init);