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path: root/drivers/net/ieee802154/cc2520.c
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Diffstat (limited to 'drivers/net/ieee802154/cc2520.c')
-rw-r--r--drivers/net/ieee802154/cc2520.c145
1 files changed, 122 insertions, 23 deletions
diff --git a/drivers/net/ieee802154/cc2520.c b/drivers/net/ieee802154/cc2520.c
index e65b60591317..d50add705a79 100644
--- a/drivers/net/ieee802154/cc2520.c
+++ b/drivers/net/ieee802154/cc2520.c
@@ -21,6 +21,8 @@
#include <linux/skbuff.h>
#include <linux/of_gpio.h>
#include <linux/ieee802154.h>
+#include <linux/crc-ccitt.h>
+#include <asm/unaligned.h>
#include <net/mac802154.h>
#include <net/cfg802154.h>
@@ -189,6 +191,18 @@
#define CC2520_RXFIFOCNT 0x3E
#define CC2520_TXFIFOCNT 0x3F
+/* CC2520_FRMFILT0 */
+#define FRMFILT0_FRAME_FILTER_EN BIT(0)
+#define FRMFILT0_PAN_COORDINATOR BIT(1)
+
+/* CC2520_FRMCTRL0 */
+#define FRMCTRL0_AUTOACK BIT(5)
+#define FRMCTRL0_AUTOCRC BIT(6)
+
+/* CC2520_FRMCTRL1 */
+#define FRMCTRL1_SET_RXENMASK_ON_TX BIT(0)
+#define FRMCTRL1_IGNORE_TX_UNDERF BIT(1)
+
/* Driver private information */
struct cc2520_private {
struct spi_device *spi; /* SPI device structure */
@@ -201,6 +215,7 @@ struct cc2520_private {
struct work_struct fifop_irqwork;/* Workqueue for FIFOP */
spinlock_t lock; /* Lock for is_tx*/
struct completion tx_complete; /* Work completion for Tx */
+ bool promiscuous; /* Flag for promiscuous mode */
};
/* Generic Functions */
@@ -367,14 +382,14 @@ cc2520_read_register(struct cc2520_private *priv, u8 reg, u8 *data)
}
static int
-cc2520_write_txfifo(struct cc2520_private *priv, u8 *data, u8 len)
+cc2520_write_txfifo(struct cc2520_private *priv, u8 pkt_len, u8 *data, u8 len)
{
int status;
/* length byte must include FCS even
* if it is calculated in the hardware
*/
- int len_byte = len + 2;
+ int len_byte = pkt_len;
struct spi_message msg;
@@ -414,7 +429,7 @@ cc2520_write_txfifo(struct cc2520_private *priv, u8 *data, u8 len)
}
static int
-cc2520_read_rxfifo(struct cc2520_private *priv, u8 *data, u8 len, u8 *lqi)
+cc2520_read_rxfifo(struct cc2520_private *priv, u8 *data, u8 len)
{
int status;
struct spi_message msg;
@@ -470,12 +485,25 @@ cc2520_tx(struct ieee802154_hw *hw, struct sk_buff *skb)
unsigned long flags;
int rc;
u8 status = 0;
+ u8 pkt_len;
+
+ /* In promiscuous mode we disable AUTOCRC so we can get the raw CRC
+ * values on RX. This means we need to manually add the CRC on TX.
+ */
+ if (priv->promiscuous) {
+ u16 crc = crc_ccitt(0, skb->data, skb->len);
+
+ put_unaligned_le16(crc, skb_put(skb, 2));
+ pkt_len = skb->len;
+ } else {
+ pkt_len = skb->len + 2;
+ }
rc = cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHTX);
if (rc)
goto err_tx;
- rc = cc2520_write_txfifo(priv, skb->data, skb->len);
+ rc = cc2520_write_txfifo(priv, pkt_len, skb->data, skb->len);
if (rc)
goto err_tx;
@@ -518,22 +546,62 @@ static int cc2520_rx(struct cc2520_private *priv)
u8 len = 0, lqi = 0, bytes = 1;
struct sk_buff *skb;
- cc2520_read_rxfifo(priv, &len, bytes, &lqi);
+ /* Read single length byte from the radio. */
+ cc2520_read_rxfifo(priv, &len, bytes);
- if (len < 2 || len > IEEE802154_MTU)
- return -EINVAL;
+ if (!ieee802154_is_valid_psdu_len(len)) {
+ /* Corrupted frame received, clear frame buffer by
+ * reading entire buffer.
+ */
+ dev_dbg(&priv->spi->dev, "corrupted frame received\n");
+ len = IEEE802154_MTU;
+ }
skb = dev_alloc_skb(len);
if (!skb)
return -ENOMEM;
- if (cc2520_read_rxfifo(priv, skb_put(skb, len), len, &lqi)) {
+ if (cc2520_read_rxfifo(priv, skb_put(skb, len), len)) {
dev_dbg(&priv->spi->dev, "frame reception failed\n");
kfree_skb(skb);
return -EINVAL;
}
- skb_trim(skb, skb->len - 2);
+ /* In promiscuous mode, we configure the radio to include the
+ * CRC (AUTOCRC==0) and we pass on the packet unconditionally. If not
+ * in promiscuous mode, we check the CRC here, but leave the
+ * RSSI/LQI/CRC_OK bytes as they will get removed in the mac layer.
+ */
+ if (!priv->promiscuous) {
+ bool crc_ok;
+
+ /* Check if the CRC is valid. With AUTOCRC set, the most
+ * significant bit of the last byte returned from the CC2520
+ * is CRC_OK flag. See section 20.3.4 of the datasheet.
+ */
+ crc_ok = skb->data[len - 1] & BIT(7);
+
+ /* If we failed CRC drop the packet in the driver layer. */
+ if (!crc_ok) {
+ dev_dbg(&priv->spi->dev, "CRC check failed\n");
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+
+ /* To calculate LQI, the lower 7 bits of the last byte (the
+ * correlation value provided by the radio) must be scaled to
+ * the range 0-255. According to section 20.6, the correlation
+ * value ranges from 50-110. Ideally this would be calibrated
+ * per hardware design, but we use roughly the datasheet values
+ * to get close enough while avoiding floating point.
+ */
+ lqi = skb->data[len - 1] & 0x7f;
+ if (lqi < 50)
+ lqi = 50;
+ else if (lqi > 113)
+ lqi = 113;
+ lqi = (lqi - 50) * 4;
+ }
ieee802154_rx_irqsafe(priv->hw, skb, lqi);
@@ -619,14 +687,19 @@ cc2520_filter(struct ieee802154_hw *hw,
}
if (changed & IEEE802154_AFILT_PANC_CHANGED) {
+ u8 frmfilt0;
+
dev_vdbg(&priv->spi->dev,
"cc2520_filter called for panc change\n");
+
+ cc2520_read_register(priv, CC2520_FRMFILT0, &frmfilt0);
+
if (filt->pan_coord)
- ret = cc2520_write_register(priv, CC2520_FRMFILT0,
- 0x02);
+ frmfilt0 |= FRMFILT0_PAN_COORDINATOR;
else
- ret = cc2520_write_register(priv, CC2520_FRMFILT0,
- 0x00);
+ frmfilt0 &= ~FRMFILT0_PAN_COORDINATOR;
+
+ ret = cc2520_write_register(priv, CC2520_FRMFILT0, frmfilt0);
}
return ret;
@@ -723,6 +796,30 @@ cc2520_set_txpower(struct ieee802154_hw *hw, s32 mbm)
return cc2520_cc2591_set_tx_power(priv, mbm);
}
+static int
+cc2520_set_promiscuous_mode(struct ieee802154_hw *hw, bool on)
+{
+ struct cc2520_private *priv = hw->priv;
+ u8 frmfilt0;
+
+ dev_dbg(&priv->spi->dev, "%s : mode %d\n", __func__, on);
+
+ priv->promiscuous = on;
+
+ cc2520_read_register(priv, CC2520_FRMFILT0, &frmfilt0);
+
+ if (on) {
+ /* Disable automatic ACK, automatic CRC, and frame filtering. */
+ cc2520_write_register(priv, CC2520_FRMCTRL0, 0);
+ frmfilt0 &= ~FRMFILT0_FRAME_FILTER_EN;
+ } else {
+ cc2520_write_register(priv, CC2520_FRMCTRL0, FRMCTRL0_AUTOACK |
+ FRMCTRL0_AUTOCRC);
+ frmfilt0 |= FRMFILT0_FRAME_FILTER_EN;
+ }
+ return cc2520_write_register(priv, CC2520_FRMFILT0, frmfilt0);
+}
+
static const struct ieee802154_ops cc2520_ops = {
.owner = THIS_MODULE,
.start = cc2520_start,
@@ -732,6 +829,7 @@ static const struct ieee802154_ops cc2520_ops = {
.set_channel = cc2520_set_channel,
.set_hw_addr_filt = cc2520_filter,
.set_txpower = cc2520_set_txpower,
+ .set_promiscuous_mode = cc2520_set_promiscuous_mode,
};
static int cc2520_register(struct cc2520_private *priv)
@@ -749,7 +847,8 @@ static int cc2520_register(struct cc2520_private *priv)
/* We do support only 2.4 Ghz */
priv->hw->phy->supported.channels[0] = 0x7FFF800;
- priv->hw->flags = IEEE802154_HW_OMIT_CKSUM | IEEE802154_HW_AFILT;
+ priv->hw->flags = IEEE802154_HW_TX_OMIT_CKSUM | IEEE802154_HW_AFILT |
+ IEEE802154_HW_PROMISCUOUS;
priv->hw->phy->flags = WPAN_PHY_FLAG_TXPOWER;
@@ -919,6 +1018,11 @@ static int cc2520_hw_init(struct cc2520_private *priv)
}
/* Registers default value: section 28.1 in Datasheet */
+
+ /* Set the CCA threshold to -50 dBm. This seems to have been copied
+ * from the TinyOS CC2520 driver and is much higher than the -84 dBm
+ * threshold suggested in the datasheet.
+ */
ret = cc2520_write_register(priv, CC2520_CCACTRL0, 0x1A);
if (ret)
goto err_ret;
@@ -955,15 +1059,10 @@ static int cc2520_hw_init(struct cc2520_private *priv)
if (ret)
goto err_ret;
- ret = cc2520_write_register(priv, CC2520_FRMCTRL0, 0x60);
- if (ret)
- goto err_ret;
-
- ret = cc2520_write_register(priv, CC2520_FRMCTRL1, 0x03);
- if (ret)
- goto err_ret;
-
- ret = cc2520_write_register(priv, CC2520_FRMFILT0, 0x00);
+ /* Configure registers correctly for this driver. */
+ ret = cc2520_write_register(priv, CC2520_FRMCTRL1,
+ FRMCTRL1_SET_RXENMASK_ON_TX |
+ FRMCTRL1_IGNORE_TX_UNDERF);
if (ret)
goto err_ret;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.