rsi: card reset for USB interface

We need to reset the chip in teardown path so that it can work
next time when driver is loaded. This patch adds support for this
reset configuration for USB.

Signed-off-by: Karun Eagalapati <karun256@gmail.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/rsi/rsi_91x_usb.c

@@ -558,6 +558,77 @@ fail_tx:
 	return status;
 }
 
+static int usb_ulp_read_write(struct rsi_hw *adapter, u16 addr, u32 data,
+			      u16 len_in_bits)
+{
+	int ret;
+
+	ret = rsi_usb_master_reg_write
+			(adapter, RSI_GSPI_DATA_REG1,
+			 ((addr << 6) | ((data >> 16) & 0xffff)), 2);
+	if (ret < 0)
+		return ret;
+
+	ret = rsi_usb_master_reg_write(adapter, RSI_GSPI_DATA_REG0,
+				       (data & 0xffff), 2);
+	if (ret < 0)
+		return ret;
+
+	/* Initializing GSPI for ULP read/writes */
+	rsi_usb_master_reg_write(adapter, RSI_GSPI_CTRL_REG0,
+				 RSI_GSPI_CTRL_REG0_VALUE, 2);
+
+	ret = rsi_usb_master_reg_write(adapter, RSI_GSPI_CTRL_REG1,
+				       ((len_in_bits - 1) | RSI_GSPI_TRIG), 2);
+	if (ret < 0)
+		return ret;
+
+	msleep(20);
+
+	return 0;
+}
+
+static int rsi_reset_card(struct rsi_hw *adapter)
+{
+	int ret;
+
+	rsi_dbg(INFO_ZONE, "Resetting Card...\n");
+	rsi_usb_master_reg_write(adapter, RSI_TA_HOLD_REG, 0xE, 4);
+
+	/* This msleep will ensure Thread-Arch processor to go to hold
+	 * and any pending dma transfers to rf in device to finish.
+	 */
+	msleep(100);
+
+	ret = usb_ulp_read_write(adapter, RSI_WATCH_DOG_TIMER_1,
+				 RSI_ULP_WRITE_2, 32);
+	if (ret < 0)
+		goto fail;
+	ret = usb_ulp_read_write(adapter, RSI_WATCH_DOG_TIMER_2,
+				 RSI_ULP_WRITE_0, 32);
+	if (ret < 0)
+		goto fail;
+	ret = usb_ulp_read_write(adapter, RSI_WATCH_DOG_DELAY_TIMER_1,
+				 RSI_ULP_WRITE_50, 32);
+	if (ret < 0)
+		goto fail;
+	ret = usb_ulp_read_write(adapter, RSI_WATCH_DOG_DELAY_TIMER_2,
+				 RSI_ULP_WRITE_0, 32);
+	if (ret < 0)
+		goto fail;
+	ret = usb_ulp_read_write(adapter, RSI_WATCH_DOG_TIMER_ENABLE,
+				 RSI_ULP_TIMER_ENABLE, 32);
+	if (ret < 0)
+		goto fail;
+
+	rsi_dbg(INFO_ZONE, "Reset card done\n");
+	return ret;
+
+fail:
+	rsi_dbg(ERR_ZONE, "Reset card failed\n");
+	return ret;
+}
+
 /**
  * rsi_probe() - This function is called by kernel when the driver provided
  *		 Vendor and device IDs are matched. All the initialization
@@ -641,6 +712,7 @@ static void rsi_disconnect(struct usb_interface *pfunction)
 		return;
 
 	rsi_mac80211_detach(adapter);
+	rsi_reset_card(adapter);
 	rsi_deinit_usb_interface(adapter);
 	rsi_91x_deinit(adapter);
 

drivers/net/wireless/rsi/rsi_usb.h

@@ -25,6 +25,7 @@
 #define USB_INTERNAL_REG_1           0x25000
 #define RSI_USB_READY_MAGIC_NUM      0xab
 #define FW_STATUS_REG                0x41050012
+#define RSI_TA_HOLD_REG              0x22000844
 
 #define USB_VENDOR_REGISTER_READ     0x15
 #define USB_VENDOR_REGISTER_WRITE    0x16