MIPS: TXx9: Add SRAMC support

Add a sysdev to access SRAM in TXx9 SoCs via sysfs.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 96 insertions, 0 deletions

diff --git a/arch/mips/txx9/generic/setup.c b/arch/mips/txx9/generic/setup.c
index 7f9101257615..3b7d77d61ce0 100644
--- a/arch/mips/txx9/generic/setup.c
+++ b/arch/mips/txx9/generic/setup.c
@@ -24,6 +24,7 @@
 #include <linux/serial_core.h>
 #include <linux/mtd/physmap.h>
 #include <linux/leds.h>
+#include <linux/sysdev.h>
 #include <asm/bootinfo.h>
 #include <asm/time.h>
 #include <asm/reboot.h>
@@ -912,3 +913,86 @@ void __init txx9_aclc_init(unsigned long baseaddr, int irq,
                 platform_device_put(pdev);
 #endif
 }
+
+static struct sysdev_class txx9_sramc_sysdev_class;
+
+struct txx9_sramc_sysdev {
+        struct sys_device dev;
+        struct bin_attribute bindata_attr;
+        void __iomem *base;
+};
+
+static ssize_t txx9_sram_read(struct kobject *kobj,
+                              struct bin_attribute *bin_attr,
+                              char *buf, loff_t pos, size_t size)
+{
+        struct txx9_sramc_sysdev *dev = bin_attr->private;
+        size_t ramsize = bin_attr->size;
+
+        if (pos >= ramsize)
+                return 0;
+        if (pos + size > ramsize)
+                size = ramsize - pos;
+        memcpy_fromio(buf, dev->base + pos, size);
+        return size;
+}
+
+static ssize_t txx9_sram_write(struct kobject *kobj,
+                               struct bin_attribute *bin_attr,
+                               char *buf, loff_t pos, size_t size)
+{
+        struct txx9_sramc_sysdev *dev = bin_attr->private;
+        size_t ramsize = bin_attr->size;
+
+        if (pos >= ramsize)
+                return 0;
+        if (pos + size > ramsize)
+                size = ramsize - pos;
+        memcpy_toio(dev->base + pos, buf, size);
+        return size;
+}
+
+void __init txx9_sramc_init(struct resource *r)
+{
+        struct txx9_sramc_sysdev *dev;
+        size_t size;
+        int err;
+
+        if (!txx9_sramc_sysdev_class.name) {
+                txx9_sramc_sysdev_class.name = "txx9_sram";
+                err = sysdev_class_register(&txx9_sramc_sysdev_class);
+                if (err) {
+                        txx9_sramc_sysdev_class.name = NULL;
+                        return;
+                }
+        }
+        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+        if (!dev)
+                return;
+        size = resource_size(r);
+        dev->base = ioremap(r->start, size);
+        if (!dev->base)
+                goto exit;
+        dev->dev.cls = &txx9_sramc_sysdev_class;
+        dev->bindata_attr.attr.name = "bindata";
+        dev->bindata_attr.attr.mode = S_IRUSR | S_IWUSR;
+        dev->bindata_attr.read = txx9_sram_read;
+        dev->bindata_attr.write = txx9_sram_write;
+        dev->bindata_attr.size = size;
+        dev->bindata_attr.private = dev;
+        err = sysdev_register(&dev->dev);
+        if (err)
+                goto exit;
+        err = sysfs_create_bin_file(&dev->dev.kobj, &dev->bindata_attr);
+        if (err) {
+                sysdev_unregister(&dev->dev);
+                goto exit;
+        }
+        return;
+exit:
+        if (dev) {
+                if (dev->base)
+                        iounmap(dev->base);
+                kfree(dev);
+        }
+}
diff --git a/arch/mips/txx9/generic/setup_tx4938.c b/arch/mips/txx9/generic/setup_tx4938.c
index 4dfdb52e8665..eb2080110239 100644
--- a/arch/mips/txx9/generic/setup_tx4938.c
+++ b/arch/mips/txx9/generic/setup_tx4938.c
@@ -425,6 +425,12 @@ void __init tx4938_aclc_init(void)
                                1, 0, 1);
 }
 
+void __init tx4938_sramc_init(void)
+{
+        if (tx4938_sram_resource.start)
+                txx9_sramc_init(&tx4938_sram_resource);
+}
+
 static void __init tx4938_stop_unused_modules(void)
 {
         __u64 pcfg, rst = 0, ckd = 0;
diff --git a/arch/mips/txx9/generic/setup_tx4939.c b/arch/mips/txx9/generic/setup_tx4939.c
index 71396863f54e..df13a891fb4b 100644
--- a/arch/mips/txx9/generic/setup_tx4939.c
+++ b/arch/mips/txx9/generic/setup_tx4939.c
@@ -494,6 +494,12 @@ void __init tx4939_aclc_init(void)
                                TXX9_IRQ_BASE + TX4939_IR_ACLC, 1, 0, 1);
 }
 
+void __init tx4939_sramc_init(void)
+{
+        if (tx4939_sram_resource.start)
+                txx9_sramc_init(&tx4939_sram_resource);
+}
+
 static void __init tx4939_stop_unused_modules(void)
 {
         __u64 pcfg, rst = 0, ckd = 0;