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authorSascha Hauer <s.hauer@pengutronix.de>2014-01-27 14:32:54 +0100
committerSascha Hauer <s.hauer@pengutronix.de>2014-01-29 10:29:47 +0100
commitae39ba29c6eee410c25eef57ab758365ada972cc (patch)
tree7cb64a67091e6b53a85875b56552e4f925ca3c80 /drivers/misc
parent27da1665d3fea543ed4829f754e60972c10458ca (diff)
downloadbarebox-ae39ba29c6eee410c25eef57ab758365ada972cc.tar.gz
misc: Add devicetree SRAM driver
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/Kconfig6
-rw-r--r--drivers/misc/Makefile1
-rw-r--r--drivers/misc/sram.c75
3 files changed, 82 insertions, 0 deletions
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index e59c4f1..c34a4af 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -9,4 +9,10 @@ config JTAG
depends on GENERIC_GPIO
help
Controls JTAG chains connected to I/O pins
+
+config SRAM
+ bool "Generic SRAM driver"
+ help
+ This driver adds support for memory mapped SRAM.
+
endmenu
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index b085577..908c8cb 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -3,3 +3,4 @@
#
obj-$(CONFIG_JTAG) += jtag.o
+obj-$(CONFIG_SRAM) += sram.o
diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
new file mode 100644
index 0000000..7ea23b7
--- /dev/null
+++ b/drivers/misc/sram.c
@@ -0,0 +1,75 @@
+/*
+ * drivers/misc/sram.c - generic memory mapped SRAM driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <driver.h>
+#include <malloc.h>
+#include <init.h>
+
+struct sram {
+ struct resource *res;
+ char *name;
+ struct cdev cdev;
+};
+
+static struct file_operations memops = {
+ .read = mem_read,
+ .write = mem_write,
+ .memmap = generic_memmap_rw,
+ .lseek = dev_lseek_default,
+};
+
+static int sram_probe(struct device_d *dev)
+{
+ struct sram *sram;
+ struct resource *res;
+ void __iomem *base;
+ int ret;
+
+ base = dev_request_mem_region(dev, 0);
+ if (!base)
+ return -EBUSY;
+
+ sram = xzalloc(sizeof(*sram));
+
+ sram->cdev.name = asprintf("sram%d",
+ cdev_find_free_index("sram"));
+
+ res = dev_get_resource(dev, 0);
+
+ sram->cdev.size = (unsigned long)resource_size(res);
+ sram->cdev.ops = &memops;
+ sram->cdev.dev = dev;
+
+ ret = devfs_create(&sram->cdev);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static __maybe_unused struct of_device_id sram_dt_ids[] = {
+ {
+ .compatible = "mmio-sram",
+ }, {
+ },
+};
+
+static struct driver_d sram_driver = {
+ .name = "mmio-sram",
+ .probe = sram_probe,
+ .of_compatible = sram_dt_ids,
+};
+device_platform_driver(sram_driver);