staging: vt6656: Refactor the vnt_rf_table_download function

Create a constant array of struct vnt_table_info type elements with the
necessary info (address and length) about all the rf tables for every rf
type.

In every case of the "switch" statement replace the hardcoded info about
these tables with and index to the new constant array. Moreover, use
this array index to extract the necessary info in every call to the
vnt_control_out_* functions.

Check if this index has been set and return without error otherwise.
So, avoid the execution of code that previously did nothing due to
lengths with values of zero for some rf types.

Also remove all the variables that are now unused.

This way reduce the stack footprint, and make the code more clear.

Signed-off-by: Oscar Carter <oscar.carter@gmx.com>
Link: https://lore.kernel.org/r/20200429153838.7216-1-oscar.carter@gmx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 69 insertions, 42 deletions

diff --git a/drivers/staging/vt6656/rf.c b/drivers/staging/vt6656/rf.c
index f18d456a8f5d..fb708467b99b 100644
--- a/drivers/staging/vt6656/rf.c
+++ b/drivers/staging/vt6656/rf.c
@@ -518,6 +518,47 @@ static u8 vt3342_channel_table1[CB_MAX_CHANNEL][3] = {
 	{0x03, 0x00, 0x04}
 };
 
+enum {
+	VNT_TABLE_INIT = 0,
+	VNT_TABLE_INIT_2 = 0,
+	VNT_TABLE_0 = 1,
+	VNT_TABLE_1 = 2,
+	VNT_TABLE_2 = 1
+};
+
+struct vnt_table_info {
+	u8 *addr;
+	int length;
+};
+
+static const struct vnt_table_info vnt_table_seq[][3] = {
+	{	/* RF_AL2230, RF_AL2230S init table, channel table 0 and 1 */
+		{&al2230_init_table[0][0], CB_AL2230_INIT_SEQ * 3},
+		{&al2230_channel_table0[0][0], CB_MAX_CHANNEL_24G * 3},
+		{&al2230_channel_table1[0][0], CB_MAX_CHANNEL_24G * 3}
+	}, {	/* RF_AIROHA7230 init table, channel table 0 and 1 */
+		{&al7230_init_table[0][0], CB_AL7230_INIT_SEQ * 3},
+		{&al7230_channel_table0[0][0], CB_MAX_CHANNEL * 3},
+		{&al7230_channel_table1[0][0], CB_MAX_CHANNEL * 3}
+	}, {	/* RF_VT3226 init table, channel table 0 and 1 */
+		{&vt3226_init_table[0][0], CB_VT3226_INIT_SEQ * 3},
+		{&vt3226_channel_table0[0][0], CB_MAX_CHANNEL_24G * 3},
+		{&vt3226_channel_table1[0][0], CB_MAX_CHANNEL_24G * 3}
+	}, {	/* RF_VT3226D0 init table, channel table 0 and 1 */
+		{&vt3226d0_init_table[0][0], CB_VT3226_INIT_SEQ * 3},
+		{&vt3226_channel_table0[0][0], CB_MAX_CHANNEL_24G * 3},
+		{&vt3226_channel_table1[0][0], CB_MAX_CHANNEL_24G * 3}
+	}, {	/* RF_VT3342A0 init table, channel table 0 and 1 */
+		{&vt3342a0_init_table[0][0], CB_VT3342_INIT_SEQ * 3},
+		{&vt3342_channel_table0[0][0], CB_MAX_CHANNEL * 3},
+		{&vt3342_channel_table1[0][0], CB_MAX_CHANNEL * 3}
+	}, {	/* RF_AIROHA7230 init table 2 and channel table 2 */
+		{&al7230_init_table_amode[0][0], CB_AL7230_INIT_SEQ * 3},
+		{&al7230_channel_table2[0][0], CB_MAX_CHANNEL * 3},
+		{NULL, 0}
+	}
+};
+
 /*
  * Description: Write to IF/RF, by embedded programming
  */
@@ -760,85 +801,71 @@ void vnt_rf_rssi_to_dbm(struct vnt_private *priv, u8 rssi, long *dbm)
 int vnt_rf_table_download(struct vnt_private *priv)
 {
 	int ret;
-	u16 length1 = 0, length2 = 0, length3 = 0;
-	u8 *addr1 = NULL, *addr2 = NULL, *addr3 = NULL;
+	int idx = -1;
+	const struct vnt_table_info *table_seq;
 
 	switch (priv->rf_type) {
 	case RF_AL2230:
 	case RF_AL2230S:
-		length1 = CB_AL2230_INIT_SEQ * 3;
-		length2 = CB_MAX_CHANNEL_24G * 3;
-		length3 = CB_MAX_CHANNEL_24G * 3;
-		addr1 = &al2230_init_table[0][0];
-		addr2 = &al2230_channel_table0[0][0];
-		addr3 = &al2230_channel_table1[0][0];
+		idx = 0;
 		break;
 	case RF_AIROHA7230:
-		length1 = CB_AL7230_INIT_SEQ * 3;
-		length2 = CB_MAX_CHANNEL * 3;
-		length3 = CB_MAX_CHANNEL * 3;
-		addr1 = &al7230_init_table[0][0];
-		addr2 = &al7230_channel_table0[0][0];
-		addr3 = &al7230_channel_table1[0][0];
+		idx = 1;
 		break;
 	case RF_VT3226:
-		length1 = CB_VT3226_INIT_SEQ * 3;
-		length2 = CB_MAX_CHANNEL_24G * 3;
-		length3 = CB_MAX_CHANNEL_24G * 3;
-		addr1 = &vt3226_init_table[0][0];
-		addr2 = &vt3226_channel_table0[0][0];
-		addr3 = &vt3226_channel_table1[0][0];
+		idx = 2;
 		break;
 	case RF_VT3226D0:
-		length1 = CB_VT3226_INIT_SEQ * 3;
-		length2 = CB_MAX_CHANNEL_24G * 3;
-		length3 = CB_MAX_CHANNEL_24G * 3;
-		addr1 = &vt3226d0_init_table[0][0];
-		addr2 = &vt3226_channel_table0[0][0];
-		addr3 = &vt3226_channel_table1[0][0];
+		idx = 3;
 		break;
 	case RF_VT3342A0:
-		length1 = CB_VT3342_INIT_SEQ * 3;
-		length2 = CB_MAX_CHANNEL * 3;
-		length3 = CB_MAX_CHANNEL * 3;
-		addr1 = &vt3342a0_init_table[0][0];
-		addr2 = &vt3342_channel_table0[0][0];
-		addr3 = &vt3342_channel_table1[0][0];
+		idx = 4;
 		break;
 	}
 
+	if (idx < 0)
+		return 0;
+
+	table_seq = &vnt_table_seq[idx][0];
+
 	/* Init Table */
 	ret = vnt_control_out(priv, MESSAGE_TYPE_WRITE, 0,
-			      MESSAGE_REQUEST_RF_INIT, length1, addr1);
+			      MESSAGE_REQUEST_RF_INIT,
+			      table_seq[VNT_TABLE_INIT].length,
+			      table_seq[VNT_TABLE_INIT].addr);
 	if (ret)
 		return ret;
 
 	/* Channel Table 0 */
 	ret = vnt_control_out_blocks(priv, VNT_REG_BLOCK_SIZE,
-				     MESSAGE_REQUEST_RF_CH0, length2, addr2);
+				     MESSAGE_REQUEST_RF_CH0,
+				     table_seq[VNT_TABLE_0].length,
+				     table_seq[VNT_TABLE_0].addr);
 	if (ret)
 		return ret;
 
 	/* Channel Table 1 */
 	ret = vnt_control_out_blocks(priv, VNT_REG_BLOCK_SIZE,
-				     MESSAGE_REQUEST_RF_CH1, length3, addr3);
+				     MESSAGE_REQUEST_RF_CH1,
+				     table_seq[VNT_TABLE_1].length,
+				     table_seq[VNT_TABLE_1].addr);
 
 	if (priv->rf_type == RF_AIROHA7230) {
-		length1 = CB_AL7230_INIT_SEQ * 3;
-		length2 = CB_MAX_CHANNEL * 3;
-		addr1 = &al7230_init_table_amode[0][0];
-		addr2 = &al7230_channel_table2[0][0];
+		table_seq = &vnt_table_seq[5][0];
 
 		/* Init Table 2 */
 		ret = vnt_control_out(priv, MESSAGE_TYPE_WRITE, 0,
-				      MESSAGE_REQUEST_RF_INIT2, length1, addr1);
+				      MESSAGE_REQUEST_RF_INIT2,
+				      table_seq[VNT_TABLE_INIT_2].length,
+				      table_seq[VNT_TABLE_INIT_2].addr);
 		if (ret)
 			return ret;
 
 		/* Channel Table 2 */
 		ret = vnt_control_out_blocks(priv, VNT_REG_BLOCK_SIZE,
-					     MESSAGE_REQUEST_RF_CH2, length2,
-					     addr2);
+					     MESSAGE_REQUEST_RF_CH2,
+					     table_seq[VNT_TABLE_2].length,
+					     table_seq[VNT_TABLE_2].addr);
 	}
 
 	return ret;