From dce481e63dc18ece7c86c607aa17b7c753fce0b7 Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Mon, 9 Mar 2015 13:56:11 +0100 Subject: [PATCH] at86rf230: add support for calibration timeout This patch adds a handling for calibration if we are 5 minutes in PLL state. I first tried to implement the calibration functionality in TX_ON state via register values CF_START and DCU_START, but this occurs a one second delay at each calibration time. An another solution to start a calibration is to switch from TRX_OFF state into TX_ON, then a calibration is done automatically by transceiver. This method will be used in this patch, after each transmit of a frame we check with jiffies if the PLL is set 5 minutes without doing a TRX_OFF->(TX_ON || RX_AACK_ON) or channel switch. The worst case would be a transceiver in receiving mode only, but this is under normal operation very unlikely. Signed-off-by: Alexander Aring Cc: Phoebe Buckheister Cc: Werner Almesberger Signed-off-by: Marcel Holtmann --- drivers/net/ieee802154/at86rf230.c | 72 ++++++++++++++++++++++++++++++-------- 1 file changed, 58 insertions(+), 14 deletions(-) diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c index 4030fa6..795106c 100644 --- a/drivers/net/ieee802154/at86rf230.c +++ b/drivers/net/ieee802154/at86rf230.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -60,6 +61,8 @@ struct at86rf2xx_chip_data { * We assume the max_frame_retries (7) value of 802.15.4 here. */ #define AT86RF2XX_MAX_TX_RETRIES 7 +/* We use the recommended 5 minutes timeout to recalibrate */ +#define AT86RF2XX_CAL_LOOP_TIMEOUT (5 * 60 * HZ) struct at86rf230_state_change { struct at86rf230_local *lp; @@ -90,6 +93,7 @@ struct at86rf230_local { struct at86rf230_state_change irq; bool tx_aret; + unsigned long cal_timeout; s8 max_frame_retries; bool is_tx; /* spinlock for is_tx protection */ @@ -491,6 +495,14 @@ at86rf230_async_read_reg(struct at86rf230_local *lp, const u8 reg, } } +static inline u8 at86rf230_state_to_force(u8 state) +{ + if (state == STATE_TX_ON) + return STATE_FORCE_TX_ON; + else + return STATE_FORCE_TRX_OFF; +} + static void at86rf230_async_state_assert(void *context) { @@ -527,11 +539,12 @@ at86rf230_async_state_assert(void *context) * higher or equal than AT86RF2XX_MAX_TX_RETRIES we * will do a force change. */ - if (ctx->to_state == STATE_TX_ON) { - u8 state = STATE_TX_ON; + if (ctx->to_state == STATE_TX_ON || + ctx->to_state == STATE_TRX_OFF) { + u8 state = ctx->to_state; if (lp->tx_retry >= AT86RF2XX_MAX_TX_RETRIES) - state = STATE_FORCE_TX_ON; + state = at86rf230_state_to_force(state); lp->tx_retry++; at86rf230_async_state_change(lp, ctx, state, @@ -599,6 +612,11 @@ at86rf230_async_state_delay(void *context) goto change; case STATE_TX_ON: tim = ktime_set(0, c->t_off_to_tx_on * NSEC_PER_USEC); + /* state change from TRX_OFF to TX_ON to do a + * calibration, we need to reset the timeout for the + * next one. + */ + lp->cal_timeout = jiffies + AT86RF2XX_CAL_LOOP_TIMEOUT; goto change; default: break; @@ -606,10 +624,11 @@ at86rf230_async_state_delay(void *context) break; case STATE_BUSY_RX_AACK: switch (ctx->to_state) { + case STATE_TRX_OFF: case STATE_TX_ON: /* Wait for worst case receiving time if we * didn't make a force change from BUSY_RX_AACK - * to TX_ON. + * to TX_ON or TRX_OFF. */ if (!force) { tim = ktime_set(0, (c->t_frame + c->t_p_ack) * @@ -969,25 +988,45 @@ at86rf230_xmit_tx_on(void *context) at86rf230_write_frame, false); } -static int -at86rf230_xmit(struct ieee802154_hw *hw, struct sk_buff *skb) +static void +at86rf230_xmit_start(void *context) { - struct at86rf230_local *lp = hw->priv; - struct at86rf230_state_change *ctx = &lp->tx; - - void (*tx_complete)(void *context) = at86rf230_write_frame; - - lp->tx_skb = skb; + struct at86rf230_state_change *ctx = context; + struct at86rf230_local *lp = ctx->lp; /* In ARET mode we need to go into STATE_TX_ARET_ON after we * are in STATE_TX_ON. The pfad differs here, so we change * the complete handler. */ if (lp->tx_aret) - tx_complete = at86rf230_xmit_tx_on; + at86rf230_async_state_change(lp, ctx, STATE_TX_ON, + at86rf230_xmit_tx_on, false); + else + at86rf230_async_state_change(lp, ctx, STATE_TX_ON, + at86rf230_write_frame, false); +} + +static int +at86rf230_xmit(struct ieee802154_hw *hw, struct sk_buff *skb) +{ + struct at86rf230_local *lp = hw->priv; + struct at86rf230_state_change *ctx = &lp->tx; + lp->tx_skb = skb; lp->tx_retry = 0; - at86rf230_async_state_change(lp, ctx, STATE_TX_ON, tx_complete, false); + + /* After 5 minutes in PLL and the same frequency we run again the + * calibration loops which is recommended by at86rf2xx datasheets. + * + * The calibration is initiate by a state change from TRX_OFF + * to TX_ON, the lp->cal_timeout should be reinit by state_delay + * function then to start in the next 5 minutes. + */ + if (time_is_before_jiffies(lp->cal_timeout)) + at86rf230_async_state_change(lp, ctx, STATE_TRX_OFF, + at86rf230_xmit_start, false); + else + at86rf230_xmit_start(ctx); return 0; } @@ -1003,6 +1042,9 @@ at86rf230_ed(struct ieee802154_hw *hw, u8 *level) static int at86rf230_start(struct ieee802154_hw *hw) { + struct at86rf230_local *lp = hw->priv; + + lp->cal_timeout = jiffies + AT86RF2XX_CAL_LOOP_TIMEOUT; return at86rf230_sync_state_change(hw->priv, STATE_RX_AACK_ON); } @@ -1083,6 +1125,8 @@ at86rf230_channel(struct ieee802154_hw *hw, u8 page, u8 channel) /* Wait for PLL */ usleep_range(lp->data->t_channel_switch, lp->data->t_channel_switch + 10); + + lp->cal_timeout = jiffies + AT86RF2XX_CAL_LOOP_TIMEOUT; return rc; } -- 2.7.4