wl1271: Configure clock-request drive mode to open-drain

This patch configures the wl1271 chipset clock-request line to be
driver in open-drain mode instead of push-pull.
Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/wl12xx/wl1271_boot.c

@@ -451,11 +451,15 @@ int wl1271_boot(struct wl1271 *wl)
 
 	if (REF_CLOCK != 0) {
 		u16 val;
-		/* Set clock type */
+		/* Set clock type (open drain) */
 		val = wl1271_top_reg_read(wl, OCP_REG_CLK_TYPE);
 		val &= FREF_CLK_TYPE_BITS;
-		val |= CLK_REQ_PRCM;
 		wl1271_top_reg_write(wl, OCP_REG_CLK_TYPE, val);
+
+		/* Set clock pull mode (no pull) */
+		val = wl1271_top_reg_read(wl, OCP_REG_CLK_PULL);
+		val |= NO_PULL;
+		wl1271_top_reg_write(wl, OCP_REG_CLK_PULL, val);
 	} else {
 		u16 val;
 		/* Set clock polarity */

drivers/net/wireless/wl12xx/wl1271_boot.h

@@ -53,10 +53,13 @@ struct wl1271_static_data {
 #define OCP_REG_POLARITY     0x0064
 #define OCP_REG_CLK_TYPE     0x0448
 #define OCP_REG_CLK_POLARITY 0x0cb2
+#define OCP_REG_CLK_PULL     0x0cb4
+
 
 #define CMD_MBOX_ADDRESS     0x407B4
 
 #define POLARITY_LOW         BIT(1)
+#define NO_PULL              (BIT(14) | BIT(15))
 
 #define FREF_CLK_TYPE_BITS     0xfffffe7f
 #define CLK_REQ_PRCM           0x100