Because we cannot wait inside start_xmit so we copy the pointer to the skb
and schedule transmission work to be done.
For the transmission a lot is hard coded to just get a signal out of the
sx1301, it looks like using a header like CAN frames do will be a good
mechanism to get information such as coding rate, spreading factor and
power into the transmission.
Signed-off-by: Ben Whitten <ben.whit...@lairdtech.com>
---
drivers/net/lora/sx1301.c | 166 +++++++++++++++++++++++++++++++++++++-
drivers/net/lora/sx1301.h | 21 +++++
2 files changed, 186 insertions(+), 1 deletion(-)
diff --git a/drivers/net/lora/sx1301.c b/drivers/net/lora/sx1301.c
index 0c7b6d0b31af..9bcbb967f307 100644
--- a/drivers/net/lora/sx1301.c
+++ b/drivers/net/lora/sx1301.c
@@ -24,6 +24,44 @@
#include "sx1301.h"
+struct sx1301_tx_header {
+ u8 tx_freq[3];
+ u32 start;
+ u8 tx_power:4,
+ modulation_type:1,
+ radio_select:1,
+ resered0:2;
+ u8 reserved1;
+
+ union {
+ struct lora_t {
+ u8 sf:4,
+ cr:3,
+ crc16_en:1;
+ u8 payload_len;
+ u8 mod_bw:2,
+ implicit_header:1,
+ ppm_offset:1,
+ invert_pol:1,
+ reserved0:3;
+ u16 preamble;
+ u8 reserved1;
+ u8 reserved2;
+ } lora;
+ struct fsk_t {
+ u8 freq_dev;
+ u8 payload_len;
+ u8 packet_mode:1,
+ crc_en:1,
+ enc_mode:2,
+ crc_mode:1,
+ reserved0:3;
+ u16 preamble;
+ u16 bitrate;
+ } fsk;
+ } u;
+} __packed;
+
static struct sx1301_tx_gain_lut tx_gain_lut[] = {
{
.dig_gain = 0,
@@ -546,9 +584,87 @@ static int sx1301_load_tx_gain_lut(struct sx1301_priv
*priv)
return ret;
};
+static int sx1301_tx(struct sx1301_priv *priv, void *data, int len)
+{
+ int ret, i;
+ u8 buff[256 + 16];
+ struct sx1301_tx_header *hdr = (struct sx1301_tx_header *)buff;
+
+ /* TODO general checks to make sure we CAN send */
+
+ /* TODO Enable notch filter for lora 125 */
+
+ /* TODO get start delay for this TX */
+
+ /* TODO interpret tx power, HACK just set max power */
+
+ /* TODO get TX imbalance for this pow index from calibration step */
+
+ /* TODO set the dig gain */
+
+ /* TODO set TX PLL freq based on radio used to TX */
+
+ memset(buff, 0, sizeof(buff));
+
+ /* HACK set to 868MHz */
+ hdr->tx_freq[0] = 217;
+ hdr->tx_freq[1] = 0;
+ hdr->tx_freq[3] = 0;
+
+ hdr->start = 0; /* Start imediatly */
+ hdr->radio_select = 0; /* HACK Radio A transmit */
+ hdr->modulation_type = 0; /* HACK modulation LORA */
+ hdr->tx_power = 15; /* HACK power entry 15 */
+
+ hdr->u.lora.crc16_en = 1; /* Enable CRC16 */
+ hdr->u.lora.cr = 1; /* CR 4/5 */
+ hdr->u.lora.sf = 7; /* SF7 */
+ hdr->u.lora.payload_len = len; /* Set the data len to the skb len */
+ hdr->u.lora.implicit_header = 0; /* No implicit header */
+ hdr->u.lora.mod_bw = 0; /* Set 125KHz BW */
+ hdr->u.lora.ppm_offset = 0; /* TODO no ppm offset? */
+ hdr->u.lora.invert_pol = 0; /* TODO set no inverted polarity */
+
+ hdr->u.lora.preamble = 8; /* Set the standard preamble */
+
+ /* TODO 2 Msb in tx_freq0 for large narrow filtering, unset for now */
+ hdr->tx_freq[0] &= 0x3F;
+
+ /* Copy the TX data into the buffer ready to go */
+
+ memcpy((void *)&buff[16], data, len);
+
+ /* Reset any transmissions */
+ ret = regmap_write(priv->regmap, SX1301_TX_TRIG, 0);
+ if (ret)
+ return ret;
+
+ /* Put the buffer into the tranmit fifo */
+ ret = regmap_write(priv->regmap, SX1301_TX_DATA_BUF_ADDR, 0);
+ if (ret)
+ return ret;
+ ret = regmap_noinc_write(priv->regmap, SX1301_TX_DATA_BUF_DATA, buff,
+ len + 16);
+ if (ret)
+ return ret;
+
+ /* HACK just go for immediate transfer */
+ ret = sx1301_field_write(priv, F_TX_TRIG_IMMEDIATE, 1);
+ if (ret)
+ return ret;
+
+ dev_dbg(priv->dev, "Transmitting packet of size %d: ", len);
+ for (i = 0; i < len + 16; i++)
+ dev_dbg(priv->dev, "%X", buff[i]);
+
+ return ret;
+}
+
static netdev_tx_t sx130x_loradev_start_xmit(struct sk_buff *skb,
struct net_device *netdev)
{
+ struct sx1301_priv *priv = netdev_priv(netdev);
+
if (skb->protocol != htons(ETH_P_LORA)) {
kfree_skb(skb);
netdev->stats.tx_dropped++;
@@ -556,11 +672,42 @@ static netdev_tx_t sx130x_loradev_start_xmit(struct
sk_buff *skb,
}
netif_stop_queue(netdev);
+ priv->tx_skb = skb;
+ queue_work(priv->wq, &priv->tx_work);
- /* TODO */
return NETDEV_TX_OK;
}
+static void sx1301_tx_work_handler(struct work_struct *ws)
+{
+ struct sx1301_priv *priv = container_of(ws, struct sx1301_priv,
+ tx_work);
+ struct net_device *netdev = dev_get_drvdata(priv->dev);
+ int ret;
+
+ netdev_dbg(netdev, "%s\n", __func__);
+
+ if (priv->tx_skb) {
+ ret = sx1301_tx(priv, priv->tx_skb->data, priv->tx_skb->len);
+ if (ret) {
+ netdev->stats.tx_errors++;
+ } else {
+ netdev->stats.tx_packets++;
+ netdev->stats.tx_bytes += priv->tx_skb->len;
+ }
+
+ if (!(netdev->flags & IFF_ECHO) ||
+ priv->tx_skb->pkt_type != PACKET_LOOPBACK ||
+ priv->tx_skb->protocol != htons(ETH_P_LORA))
+ kfree_skb(priv->tx_skb);
+
+ priv->tx_skb = NULL;
+ }
+
+ if (netif_queue_stopped(netdev))
+ netif_wake_queue(netdev);
+}
+
static int sx130x_loradev_open(struct net_device *netdev)
{
struct sx1301_priv *priv = netdev_priv(netdev);
@@ -676,6 +823,12 @@ static int sx130x_loradev_open(struct net_device *netdev)
if (ret)
return ret;
+ priv->tx_skb = NULL;
+
+ priv->wq = alloc_workqueue("sx1301_wq",
+ WQ_FREEZABLE | WQ_MEM_RECLAIM, 0);
+ INIT_WORK(&priv->tx_work, sx1301_tx_work_handler);
+
netif_start_queue(netdev);
return 0;
@@ -683,11 +836,22 @@ static int sx130x_loradev_open(struct net_device *netdev)
static int sx130x_loradev_stop(struct net_device *netdev)
{
+ struct sx1301_priv *priv = netdev_priv(netdev);
+
netdev_dbg(netdev, "%s", __func__);
netif_stop_queue(netdev);
close_loradev(netdev);
+ destroy_workqueue(priv->wq);
+ priv->wq = NULL;
+
+ if (priv->tx_skb)
+ netdev->stats.tx_errors++;
+ if (priv->tx_skb)
+ dev_kfree_skb(priv->tx_skb);
+ priv->tx_skb = NULL;
+
return 0;
}
diff --git a/drivers/net/lora/sx1301.h b/drivers/net/lora/sx1301.h
index 04c9af64c181..86116f3a1fa4 100644
--- a/drivers/net/lora/sx1301.h
+++ b/drivers/net/lora/sx1301.h
@@ -28,6 +28,10 @@
/* Page independent */
#define SX1301_PAGE 0x00
#define SX1301_VER 0x01
+#define SX1301_RX_DATA_BUF_ADDR 0x02 /* 16 wide */
+#define SX1301_RX_DATA_BUF_DATA 0x04
+#define SX1301_TX_DATA_BUF_ADDR 0x05
+#define SX1301_TX_DATA_BUF_DATA 0x06
#define SX1301_MPA 0x09
#define SX1301_MPD 0x0A
#define SX1301_GEN 0x10
@@ -45,6 +49,9 @@
#define SX1301_FORCE_CTRL (SX1301_PAGE_BASE(0) + 0x69)
#define SX1301_MCU_CTRL (SX1301_PAGE_BASE(0) + 0x6A)
+/* Page 1 */
+#define SX1301_TX_TRIG (SX1301_PAGE_BASE(1) + 0x21)
+
/* Page 2 */
#define SX1301_RADIO_A_SPI_DATA (SX1301_PAGE_BASE(2) + 0x21)
#define SX1301_RADIO_A_SPI_DATA_RB (SX1301_PAGE_BASE(2) + 0x22)
@@ -83,6 +90,10 @@ enum sx1301_fields {
F_FORCE_DEC_FILTER_GAIN,
F_EMERGENCY_FORCE_HOST_CTRL,
+
+ F_TX_TRIG_IMMEDIATE,
+ F_TX_TRIG_DELAYED,
+ F_TX_TRIG_GPS,
};
static const struct reg_field sx1301_regmap_fields[] = {
@@ -108,6 +119,11 @@ static const struct reg_field sx1301_regmap_fields[] = {
/* EMERGENCY_FORCE_HOST_CTRL */
[F_EMERGENCY_FORCE_HOST_CTRL] =
REG_FIELD(SX1301_EMERGENCY_FORCE_HOST_CTRL, 0, 0),
+ /* TX_TRIG */
+ [F_TX_TRIG_IMMEDIATE] = REG_FIELD(SX1301_TX_TRIG, 0, 0),
+ [F_TX_TRIG_DELAYED] = REG_FIELD(SX1301_TX_TRIG, 1, 1),
+ [F_TX_TRIG_GPS] = REG_FIELD(SX1301_TX_TRIG, 2, 2),
+
};
struct sx1301_tx_gain_lut {
@@ -126,6 +142,11 @@ struct sx1301_priv {
struct regmap *regmap;
struct regmap_field *regmap_fields[ARRAY_SIZE(sx1301_regmap_fields)];
+ struct sk_buff *tx_skb;
+
+ struct workqueue_struct *wq;
+ struct work_struct tx_work;
+
struct sx1301_tx_gain_lut tx_gain_lut[SX1301_TX_GAIN_LUT_MAX];
u8 tx_gain_lut_size;
};
--
2.17.1
