HID: wiimote: Add read-mem helpers

Add helper functions similar to the write-mem helpers but for reading wiimote
memory and eeprom.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

2 files changed, 81 insertions, 0 deletions

diff --git a/drivers/hid/hid-wiimote-core.c b/drivers/hid/hid-wiimote-core.c
index c955d500c81f..f7f8b7ff7dec 100644
--- a/drivers/hid/hid-wiimote-core.c
+++ b/drivers/hid/hid-wiimote-core.c
@@ -312,6 +312,37 @@ static void wiiproto_req_wmem(struct wiimote_data *wdata, bool eeprom,
         wiimote_queue(wdata, cmd, sizeof(cmd));
 }
 
+#define wiiproto_req_rreg(wdata, os, sz) \
+                                wiiproto_req_rmem((wdata), false, (os), (sz))
+
+#define wiiproto_req_reeprom(wdata, os, sz) \
+                                wiiproto_req_rmem((wdata), true, (os), (sz))
+
+static void wiiproto_req_rmem(struct wiimote_data *wdata, bool eeprom,
+                                                __u32 offset, __u16 size)
+{
+        __u8 cmd[7];
+
+        if (size == 0) {
+                hid_warn(wdata->hdev, "Invalid length %d rmem request\n", size);
+                return;
+        }
+
+        cmd[0] = WIIPROTO_REQ_RMEM;
+        cmd[1] = 0;
+        cmd[2] = (offset >> 16) & 0xff;
+        cmd[3] = (offset >> 8) & 0xff;
+        cmd[4] = offset & 0xff;
+        cmd[5] = (size >> 8) & 0xff;
+        cmd[6] = size & 0xff;
+
+        if (!eeprom)
+                cmd[1] |= 0x04;
+
+        wiiproto_keep_rumble(wdata, &cmd[1]);
+        wiimote_queue(wdata, cmd, sizeof(cmd));
+}
+
 /* requries the cmd-mutex to be held */
 int wiimote_cmd_write(struct wiimote_data *wdata, __u32 offset,
                                                 const __u8 *wmem, __u8 size)
@@ -331,6 +362,36 @@ int wiimote_cmd_write(struct wiimote_data *wdata, __u32 offset,
         return ret;
 }
 
+/* requries the cmd-mutex to be held */
+ssize_t wiimote_cmd_read(struct wiimote_data *wdata, __u32 offset, __u8 *rmem,
+                                                                __u8 size)
+{
+        unsigned long flags;
+        ssize_t ret;
+
+        spin_lock_irqsave(&wdata->state.lock, flags);
+        wdata->state.cmd_read_size = size;
+        wdata->state.cmd_read_buf = rmem;
+        wiimote_cmd_set(wdata, WIIPROTO_REQ_RMEM, offset & 0xffff);
+        wiiproto_req_rreg(wdata, offset, size);
+        spin_unlock_irqrestore(&wdata->state.lock, flags);
+
+        ret = wiimote_cmd_wait(wdata);
+
+        spin_lock_irqsave(&wdata->state.lock, flags);
+        wdata->state.cmd_read_buf = NULL;
+        spin_unlock_irqrestore(&wdata->state.lock, flags);
+
+        if (!ret) {
+                if (wdata->state.cmd_read_size == 0)
+                        ret = -EIO;
+                else
+                        ret = wdata->state.cmd_read_size;
+        }
+
+        return ret;
+}
+
 static int wiimote_battery_get_property(struct power_supply *psy,
                                                 enum power_supply_property psp,
                                                 union power_supply_propval *val)
@@ -742,7 +803,23 @@ static void handler_status(struct wiimote_data *wdata, const __u8 *payload)
 
 static void handler_data(struct wiimote_data *wdata, const __u8 *payload)
 {
+        __u16 offset = payload[3] << 8 | payload[4];
+        __u8 size = (payload[2] >> 4) + 1;
+        __u8 err = payload[2] & 0x0f;
+
         handler_keys(wdata, payload);
+
+        if (wiimote_cmd_pending(wdata, WIIPROTO_REQ_RMEM, offset)) {
+                if (err)
+                        size = 0;
+                else if (size > wdata->state.cmd_read_size)
+                        size = wdata->state.cmd_read_size;
+
+                wdata->state.cmd_read_size = size;
+                if (wdata->state.cmd_read_buf)
+                        memcpy(wdata->state.cmd_read_buf, &payload[5], size);
+                wiimote_cmd_complete(wdata);
+        }
 }
 
 static void handler_return(struct wiimote_data *wdata, const __u8 *payload)
diff --git a/drivers/hid/hid-wiimote.h b/drivers/hid/hid-wiimote.h
index d78f79c08901..865740d3a3fe 100644
--- a/drivers/hid/hid-wiimote.h
+++ b/drivers/hid/hid-wiimote.h
@@ -62,6 +62,8 @@ struct wiimote_state {
         /* results of synchronous requests */
         __u8 cmd_battery;
         __u8 cmd_err;
+        __u8 *cmd_read_buf;
+        __u8 cmd_read_size;
 };
 
 struct wiimote_data {
@@ -113,6 +115,8 @@ enum wiiproto_reqs {
 extern void wiiproto_req_drm(struct wiimote_data *wdata, __u8 drm);
 extern int wiimote_cmd_write(struct wiimote_data *wdata, __u32 offset,
                                                 const __u8 *wmem, __u8 size);
+extern ssize_t wiimote_cmd_read(struct wiimote_data *wdata, __u32 offset,
+                                                        __u8 *rmem, __u8 size);
 
 /* requires the state.lock spinlock to be held */
 static inline bool wiimote_cmd_pending(struct wiimote_data *wdata, int cmd,