libertas: get SD8688 rx length with one CMD52

Usually, the 16-bit rx length is read from scratch pad registers
with two CMD52 transactions:
SD8385: 	IF_SDIO_SCRATCH_OLD (0x80fe/0x80ff)
SD8686/SD8688:	IF_SDIO_SCRATCH     (0x34/0x35)

Alternatively, SD8688 firmware offers an enhanced method for driver
to read an 8-bit rx length (in units) with a single CMD52:
IF_SDIO_RX_UNIT 0x43 is read one time after firmware is ready.
IF_SDIO_RX_LEN  0x42 is read every time when rx interrupt is received.

Signed-off-by: Bing Zhao <bzhao@marvell.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libertas/if_sdio.c
index 69d7fd3..e998c12 100644 (file)
--- a/drivers/net/wireless/libertas/if_sdio.c
+++ b/drivers/net/wireless/libertas/if_sdio.c
@@ -107,6 +107,8 @@ struct if_sdio_card {
 
        struct workqueue_struct *workqueue;
        struct work_struct      packet_worker;
+
+       u8                      rx_unit;
 };
 
 /********************************************************************/
@@ -136,6 +138,46 @@ static u16 if_sdio_read_scratch(struct if_sdio_card *card, int *err)
        return scratch;
 }
 
+static u8 if_sdio_read_rx_unit(struct if_sdio_card *card)
+{
+       int ret;
+       u8 rx_unit;
+
+       rx_unit = sdio_readb(card->func, IF_SDIO_RX_UNIT, &ret);
+
+       if (ret)
+               rx_unit = 0;
+
+       return rx_unit;
+}
+
+static u16 if_sdio_read_rx_len(struct if_sdio_card *card, int *err)
+{
+       int ret;
+       u16 rx_len;
+
+       switch (card->model) {
+       case IF_SDIO_MODEL_8385:
+       case IF_SDIO_MODEL_8686:
+               rx_len = if_sdio_read_scratch(card, &ret);
+               break;
+       case IF_SDIO_MODEL_8688:
+       default: /* for newer chipsets */
+               rx_len = sdio_readb(card->func, IF_SDIO_RX_LEN, &ret);
+               if (!ret)
+                       rx_len <<= card->rx_unit;
+               else
+                       rx_len = 0xffff;        /* invalid length */
+
+               break;
+       }
+
+       if (err)
+               *err = ret;
+
+       return rx_len;
+}
+
 static int if_sdio_handle_cmd(struct if_sdio_card *card,
                u8 *buffer, unsigned size)
 {
@@ -254,7 +296,7 @@ static int if_sdio_card_to_host(struct if_sdio_card *card)
 
        lbs_deb_enter(LBS_DEB_SDIO);
 
-       size = if_sdio_read_scratch(card, &ret);
+       size = if_sdio_read_rx_len(card, &ret);
        if (ret)
                goto out;
 
@@ -923,10 +965,21 @@ static int if_sdio_probe(struct sdio_func *func,
 
        priv->fw_ready = 1;
 
+       sdio_claim_host(func);
+
+       /*
+        * Get rx_unit if the chip is SD8688 or newer.
+        * SD8385 & SD8686 do not have rx_unit.
+        */
+       if ((card->model != IF_SDIO_MODEL_8385)
+                       && (card->model != IF_SDIO_MODEL_8686))
+               card->rx_unit = if_sdio_read_rx_unit(card);
+       else
+               card->rx_unit = 0;
+
        /*
         * Enable interrupts now that everything is set up
         */
-       sdio_claim_host(func);
        sdio_writeb(func, 0x0f, IF_SDIO_H_INT_MASK, &ret);
        sdio_release_host(func);
        if (ret)

diff --git a/drivers/net/wireless/libertas/if_sdio.h b/drivers/net/wireless/libertas/if_sdio.h
index cea343f..d3a4fbe 100644 (file)
--- a/drivers/net/wireless/libertas/if_sdio.h
+++ b/drivers/net/wireless/libertas/if_sdio.h
@@ -44,6 +44,9 @@
 #define IF_SDIO_SCRATCH_OLD    0x80fe
 #define   IF_SDIO_FIRMWARE_OK  0xfedc
 
+#define IF_SDIO_RX_LEN         0x42
+#define IF_SDIO_RX_UNIT                0x43
+
 #define IF_SDIO_EVENT           0x80fc
 
 #define IF_SDIO_BLOCK_SIZE     256