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authorLinus Walleij <linus.walleij@linaro.org>2017-12-22 00:19:08 +0100
committerArnd Bergmann <arnd@arndb.de>2018-01-04 17:01:53 +0100
commit68198dca45691be91c171a119f78e4933472053b (patch)
treeff3d044e95c89cdb1a47cfcb6f39cf5f71a4b2f6 /drivers/soc
parent11c9dff045484f5945af9ca786f9d2539320c0d4 (diff)
soc: Add SoC driver for Gemini
This adds an SoC driver for the Gemini. Currently there is only one thing not fitting into any other framework, and that is the bus arbitration setting. All Gemini vendor trees seem to be setting this register to exactly the same arbitration so we just add a small code snippet to do this at subsys_init() time before any other drivers kick in. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'drivers/soc')
-rw-r--r--drivers/soc/Makefile1
-rw-r--r--drivers/soc/gemini/Makefile2
-rw-r--r--drivers/soc/gemini/soc-gemini.c71
3 files changed, 74 insertions, 0 deletions
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index deecb16e7256..342768df3530 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -9,6 +9,7 @@ obj-y += bcm/
obj-$(CONFIG_ARCH_DOVE) += dove/
obj-$(CONFIG_MACH_DOVE) += dove/
obj-y += fsl/
+obj-$(CONFIG_ARCH_GEMINI) += gemini/
obj-$(CONFIG_ARCH_MXC) += imx/
obj-$(CONFIG_SOC_XWAY) += lantiq/
obj-y += mediatek/
diff --git a/drivers/soc/gemini/Makefile b/drivers/soc/gemini/Makefile
new file mode 100644
index 000000000000..8cbd1e45db78
--- /dev/null
+++ b/drivers/soc/gemini/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y += soc-gemini.o
diff --git a/drivers/soc/gemini/soc-gemini.c b/drivers/soc/gemini/soc-gemini.c
new file mode 100644
index 000000000000..642b96c91ad6
--- /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);

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