at86rf230: replace state change sleeps with hrtimer

This patch replace the state change timing relevant sleeps with
hrtimers. Currently the sleeps are done in the complete handler of
spi_async. The relation of doing the state change timing sleep with a
timer will get the sleep functionality out of spi_async complete handler
context.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 29 insertions, 10 deletions

diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c
index edf575c88345..4030fa69f176 100644
--- a/drivers/net/ieee802154/at86rf230.c
+++ b/drivers/net/ieee802154/at86rf230.c
@@ -19,6 +19,7 @@
  */
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/hrtimer.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/gpio.h>
@@ -64,6 +65,7 @@ struct at86rf230_state_change {
         struct at86rf230_local *lp;
         int irq;
 
+        struct hrtimer timer;
         struct spi_message msg;
         struct spi_transfer trx;
         u8 buf[AT86RF2XX_MAX_BUF];
@@ -548,6 +550,19 @@ done:
                 ctx->complete(context);
 }
 
+static enum hrtimer_restart at86rf230_async_state_timer(struct hrtimer *timer)
+{
+        struct at86rf230_state_change *ctx =
+                container_of(timer, struct at86rf230_state_change, timer);
+        struct at86rf230_local *lp = ctx->lp;
+
+        at86rf230_async_read_reg(lp, RG_TRX_STATUS, ctx,
+                                 at86rf230_async_state_assert,
+                                 ctx->irq_enable);
+
+        return HRTIMER_NORESTART;
+}
+
 /* Do state change timing delay. */
 static void
 at86rf230_async_state_delay(void *context)
@@ -556,6 +571,7 @@ at86rf230_async_state_delay(void *context)
         struct at86rf230_local *lp = ctx->lp;
         struct at86rf2xx_chip_data *c = lp->data;
         bool force = false;
+        ktime_t tim;
 
         /* The force state changes are will show as normal states in the
          * state status subregister. We change the to_state to the
@@ -579,11 +595,10 @@ at86rf230_async_state_delay(void *context)
         case STATE_TRX_OFF:
                 switch (ctx->to_state) {
                 case STATE_RX_AACK_ON:
-                        usleep_range(c->t_off_to_aack, c->t_off_to_aack + 10);
+                        tim = ktime_set(0, c->t_off_to_aack * NSEC_PER_USEC);
                         goto change;
                 case STATE_TX_ON:
-                        usleep_range(c->t_off_to_tx_on,
-                                     c->t_off_to_tx_on + 10);
+                        tim = ktime_set(0, c->t_off_to_tx_on * NSEC_PER_USEC);
                         goto change;
                 default:
                         break;
@@ -597,8 +612,8 @@ at86rf230_async_state_delay(void *context)
                          * to TX_ON.
                          */
                         if (!force) {
-                                usleep_range(c->t_frame + c->t_p_ack,
-                                             c->t_frame + c->t_p_ack + 1000);
+                                tim = ktime_set(0, (c->t_frame + c->t_p_ack) *
+                                                   NSEC_PER_USEC);
                                 goto change;
                         }
                         break;
@@ -610,7 +625,7 @@ at86rf230_async_state_delay(void *context)
         case STATE_P_ON:
                 switch (ctx->to_state) {
                 case STATE_TRX_OFF:
-                        usleep_range(c->t_reset_to_off, c->t_reset_to_off + 10);
+                        tim = ktime_set(0, c->t_reset_to_off * NSEC_PER_USEC);
                         goto change;
                 default:
                         break;
@@ -621,12 +636,10 @@ at86rf230_async_state_delay(void *context)
         }
 
         /* Default delay is 1us in the most cases */
-        udelay(1);
+        tim = ktime_set(0, NSEC_PER_USEC);
 
 change:
-        at86rf230_async_read_reg(lp, RG_TRX_STATUS, ctx,
-                                 at86rf230_async_state_assert,
-                                 ctx->irq_enable);
+        hrtimer_start(&ctx->timer, tim, HRTIMER_MODE_REL);
 }
 
 static void
@@ -1546,6 +1559,8 @@ at86rf230_setup_spi_messages(struct at86rf230_local *lp)
         lp->state.trx.tx_buf = lp->state.buf;
         lp->state.trx.rx_buf = lp->state.buf;
         spi_message_add_tail(&lp->state.trx, &lp->state.msg);
+        hrtimer_init(&lp->state.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+        lp->state.timer.function = at86rf230_async_state_timer;
 
         lp->irq.lp = lp;
         lp->irq.irq = lp->spi->irq;
@@ -1555,6 +1570,8 @@ at86rf230_setup_spi_messages(struct at86rf230_local *lp)
         lp->irq.trx.tx_buf = lp->irq.buf;
         lp->irq.trx.rx_buf = lp->irq.buf;
         spi_message_add_tail(&lp->irq.trx, &lp->irq.msg);
+        hrtimer_init(&lp->irq.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+        lp->irq.timer.function = at86rf230_async_state_timer;
 
         lp->tx.lp = lp;
         lp->tx.irq = lp->spi->irq;
@@ -1564,6 +1581,8 @@ at86rf230_setup_spi_messages(struct at86rf230_local *lp)
         lp->tx.trx.tx_buf = lp->tx.buf;
         lp->tx.trx.rx_buf = lp->tx.buf;
         spi_message_add_tail(&lp->tx.trx, &lp->tx.msg);
+        hrtimer_init(&lp->tx.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+        lp->tx.timer.function = at86rf230_async_state_timer;
 }
 
 static int at86rf230_probe(struct spi_device *spi)