b43: Add debugfs files for MMIO register access

This adds debugfs files for reading and writing arbitrary
wireless core registers. This is useful for debugging.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 133 insertions, 0 deletions

diff --git a/drivers/net/wireless/b43/debugfs.c b/drivers/net/wireless/b43/debugfs.c
index 210e2789c1c3..9cdd9eca0822 100644
--- a/drivers/net/wireless/b43/debugfs.c
+++ b/drivers/net/wireless/b43/debugfs.c
@@ -74,6 +74,115 @@ struct b43_dfs_file * fops_to_dfs_file(struct b43_wldev *dev,
         } while (0)
 
 
+/* The biggest MMIO address that we allow access to from the debugfs files. */
+#define B43_MAX_MMIO_ACCESS     (0xF00 - 1)
+
+static ssize_t mmio16read__read_file(struct b43_wldev *dev,
+                                     char *buf, size_t bufsize)
+{
+        ssize_t count = 0;
+        unsigned int addr;
+        u16 val;
+
+        addr = dev->dfsentry->mmio16read_next;
+        if (addr > B43_MAX_MMIO_ACCESS)
+                return -EDESTADDRREQ;
+
+        val = b43_read16(dev, addr);
+        fappend("0x%04X\n", val);
+
+        return count;
+}
+
+static int mmio16read__write_file(struct b43_wldev *dev,
+                                  const char *buf, size_t count)
+{
+        unsigned int addr;
+        int res;
+
+        res = sscanf(buf, "0x%X", &addr);
+        if (res != 1)
+                return -EINVAL;
+        if (addr > B43_MAX_MMIO_ACCESS)
+                return -EADDRNOTAVAIL;
+
+        dev->dfsentry->mmio16read_next = addr;
+
+        return 0;
+}
+
+static int mmio16write__write_file(struct b43_wldev *dev,
+                                   const char *buf, size_t count)
+{
+        unsigned int addr, val;
+        int res;
+
+        res = sscanf(buf, "0x%X = 0x%X", &addr, &val);
+        if (res != 2)
+                return -EINVAL;
+        if (addr > B43_MAX_MMIO_ACCESS)
+                return -EADDRNOTAVAIL;
+        if (val > 0xFFFF)
+                return -E2BIG;
+
+        b43_write16(dev, addr, val);
+
+        return 0;
+}
+
+static ssize_t mmio32read__read_file(struct b43_wldev *dev,
+                                     char *buf, size_t bufsize)
+{
+        ssize_t count = 0;
+        unsigned int addr;
+        u32 val;
+
+        addr = dev->dfsentry->mmio32read_next;
+        if (addr > B43_MAX_MMIO_ACCESS)
+                return -EDESTADDRREQ;
+
+        val = b43_read32(dev, addr);
+        fappend("0x%08X\n", val);
+
+        return count;
+}
+
+static int mmio32read__write_file(struct b43_wldev *dev,
+                                  const char *buf, size_t count)
+{
+        unsigned int addr;
+        int res;
+
+        res = sscanf(buf, "0x%X", &addr);
+        if (res != 1)
+                return -EINVAL;
+        if (addr > B43_MAX_MMIO_ACCESS)
+                return -EADDRNOTAVAIL;
+
+        dev->dfsentry->mmio32read_next = addr;
+
+        return 0;
+}
+
+static int mmio32write__write_file(struct b43_wldev *dev,
+                                   const char *buf, size_t count)
+{
+        unsigned int addr, val;
+        int res;
+
+        res = sscanf(buf, "0x%X = 0x%X", &addr, &val);
+        if (res != 2)
+                return -EINVAL;
+        if (addr > B43_MAX_MMIO_ACCESS)
+                return -EADDRNOTAVAIL;
+        if (val > 0xFFFFFFFF)
+                return -E2BIG;
+
+        b43_write32(dev, addr, val);
+
+        return 0;
+}
+
 /* wl->irq_lock is locked */
 static ssize_t tsf_read_file(struct b43_wldev *dev,
                              char *buf, size_t bufsize)
@@ -496,6 +605,10 @@ out_unlock:
                 .take_irqlock   = _take_irqlock,                \
         }
 
+B43_DEBUGFS_FOPS(mmio16read, mmio16read__read_file, mmio16read__write_file, 1);
+B43_DEBUGFS_FOPS(mmio16write, NULL, mmio16write__write_file, 1);
+B43_DEBUGFS_FOPS(mmio32read, mmio32read__read_file, mmio32read__write_file, 1);
+B43_DEBUGFS_FOPS(mmio32write, NULL, mmio32write__write_file, 1);
 B43_DEBUGFS_FOPS(tsf, tsf_read_file, tsf_write_file, 1);
 B43_DEBUGFS_FOPS(ucode_regs, ucode_regs_read_file, NULL, 1);
 B43_DEBUGFS_FOPS(shm, shm_read_file, NULL, 1);
@@ -584,6 +697,9 @@ void b43_debugfs_add_device(struct b43_wldev *dev)
                 return;
         }
 
+        e->mmio16read_next = 0xFFFF; /* invalid address */
+        e->mmio32read_next = 0xFFFF; /* invalid address */
+
 #define ADD_FILE(name, mode)    \
         do {                                                    \
                 struct dentry *d;                               \
@@ -596,6 +712,10 @@ void b43_debugfs_add_device(struct b43_wldev *dev)
         } while (0)
 
 
+        ADD_FILE(mmio16read, 0600);
+        ADD_FILE(mmio16write, 0200);
+        ADD_FILE(mmio32read, 0600);
+        ADD_FILE(mmio32write, 0200);
         ADD_FILE(tsf, 0600);
         ADD_FILE(ucode_regs, 0400);
         ADD_FILE(shm, 0400);
@@ -620,6 +740,10 @@ void b43_debugfs_remove_device(struct b43_wldev *dev)
                 return;
         b43_remove_dynamic_debug(dev);
 
+        debugfs_remove(e->file_mmio16read.dentry);
+        debugfs_remove(e->file_mmio16write.dentry);
+        debugfs_remove(e->file_mmio32read.dentry);
+        debugfs_remove(e->file_mmio32write.dentry);
         debugfs_remove(e->file_tsf.dentry);
         debugfs_remove(e->file_ucode_regs.dentry);
         debugfs_remove(e->file_shm.dentry);
diff --git a/drivers/net/wireless/b43/debugfs.h b/drivers/net/wireless/b43/debugfs.h
index c75cff4151d9..d6848696cee0 100644
--- a/drivers/net/wireless/b43/debugfs.h
+++ b/drivers/net/wireless/b43/debugfs.h
@@ -36,6 +36,10 @@ struct b43_dfsentry {
         struct b43_wldev *dev;
         struct dentry *subdir;
 
+        struct b43_dfs_file file_mmio16read;
+        struct b43_dfs_file file_mmio16write;
+        struct b43_dfs_file file_mmio32read;
+        struct b43_dfs_file file_mmio32write;
         struct b43_dfs_file file_tsf;
         struct b43_dfs_file file_ucode_regs;
         struct b43_dfs_file file_shm;
@@ -46,6 +50,11 @@ struct b43_dfsentry {
 
         struct b43_txstatus_log txstatlog;
 
+        /* The cached address for the next mmio16read file read */
+        u16 mmio16read_next;
+        /* The cached address for the next mmio32read file read */
+        u16 mmio32read_next;
+
         /* Enabled/Disabled list for the dynamic debugging features. */
         u32 dyn_debug[__B43_NR_DYNDBG];
         /* Dentries for the dynamic debugging entries. */