can: mfd: apalis-tk1-k20:increased clock speed, zero copy

Increased SPI speed for transfers and peripheral speed.
Switch to cleaning IRQ flags on read, instead of separate write.
Switched to zero-copy on SPI reads.

Signed-off-by: Dominik Sliwa <dominik.sliwa@toradex.com>
Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>

3 files changed, 12 insertions, 78 deletions

diff --git a/drivers/mfd/apalis-tk1-k20-ezp.h b/drivers/mfd/apalis-tk1-k20-ezp.h
index c8b0c518980a..92ab497dd5c7 100644
--- a/drivers/mfd/apalis-tk1-k20-ezp.h
+++ b/drivers/mfd/apalis-tk1-k20-ezp.h
@@ -37,7 +37,7 @@
 #define APALIS_TK1_K20_EZP_STA_WEF	BIT(6)
 #define APALIS_TK1_K20_EZP_STA_FS	BIT(7)
 
-#define APALIS_TK1_K20_EZP_MAX_SPEED	2000000
+#define APALIS_TK1_K20_EZP_MAX_SPEED	3000000
 #define APALIS_TK1_K20_EZP_MAX_DATA	32
 #define APALIS_TK1_K20_EZP_WRITE_SIZE	32
 
diff --git a/drivers/mfd/apalis-tk1-k20.c b/drivers/mfd/apalis-tk1-k20.c
index 9befabd5d1df..84774538eb44 100644
--- a/drivers/mfd/apalis-tk1-k20.c
+++ b/drivers/mfd/apalis-tk1-k20.c
@@ -68,13 +68,12 @@ static int apalis_tk1_k20_spi_read(void *context, const void *reg,
 {
 	unsigned char w[APALIS_TK1_K20_MAX_BULK] = {APALIS_TK1_K20_READ_INST,
 			val_size, *((unsigned char *) reg)};
-	unsigned char r[APALIS_TK1_K20_MAX_BULK];
 	unsigned char *p = val;
 	struct device *dev = context;
 	struct spi_device *spi = to_spi_device(dev);
 	struct spi_transfer t = {
 		.tx_buf = w,
-		.rx_buf = r,
+		.rx_buf = NULL,
 		.len = 3,
 		.cs_change = 0,
 		.delay_usecs = 0,
@@ -97,7 +96,8 @@ static int apalis_tk1_k20_spi_read(void *context, const void *reg,
 		spi_message_add_tail(&t, &m);
 		ret = spi_sync(spi, &m);
 		/* no need to reinit the message*/
-		t.len = 2;
+		t.len = 1;
+		t.rx_buf = p;
 		/* just use the same transfer */
 		ret = spi_sync(spi, &m);
 
@@ -108,56 +108,16 @@ static int apalis_tk1_k20_spi_read(void *context, const void *reg,
 		spi_message_add_tail(&t, &m);
 		ret = spi_sync(spi, &m);
 		/* no need to reinit the message*/
-		t.len = val_size + 1;
+		t.len = val_size;
+		t.rx_buf = p;
 		/* just use the same transfer */
 		ret = spi_sync(spi, &m);
 
 #endif
-
-#ifdef CONFIG_EXPERIMENTAL_K20_HSMODE
-	} else if ((val_size > 1) && (val_size < APALIS_TK1_K20_MAX_BULK)) {
-		spi_message_init(&m);
-		w[0] = APALIS_TK1_K20_BULK_READ_INST;
-		t.len = 3;
-		spi_message_add_tail(&t, &m);
-		ret = spi_sync(spi, &m);
-
-		if (val_size == 2) {
-			ret = spi_sync(spi, &m);
-		} else {
-			transfer_count = val_size;
-			spi_message_init(&m);
-			ts[0].tx_buf = NULL;
-			ts[0].rx_buf = r;
-			ts[0].len = (transfer_count >= 4) ? 4 : transfer_count;
-			ts[0].cs_change = 0;
-			ts[0].delay_usecs = 2;
-
-			spi_message_add_tail(&ts[i], &m);
-			/*
-			 * decrease count but remember about an extra character
-			 * at the transfer beginning
-			 */
-			transfer_count = transfer_count - ts[0].len + 1;
-
-			for (i = 1; transfer_count > 0; i++) {
-				ts[i].tx_buf = NULL;
-				/* first entry in r is the status */
-				ts[i].rx_buf = &r[(4 * i) - 1];
-				ts[i].len = (transfer_count >= 4) ?
-						4 : transfer_count;
-				ts[i].cs_change = 0;
-				ts[i].delay_usecs = 2;
-				spi_message_add_tail(&ts[i], &m);
-				transfer_count = transfer_count - ts[i].len;
-			}
-		ret = spi_sync(spi, &m);
-		}
-#endif
 	} else {
 		return -ENOTSUPP;
 	}
-
+#if 0
 	if (r[0] == TK1_K20_SENTINEL)
 		memcpy(p, &r[1], val_size);
 	else {
@@ -187,10 +147,11 @@ static int apalis_tk1_k20_spi_read(void *context, const void *reg,
 		}
 		return -EIO;
 	}
-
+#endif
 	return ret;
 }
 
+
 static int apalis_tk1_k20_spi_write(void *context, const void *data,
 		size_t count)
 {
@@ -940,7 +901,7 @@ int apalis_tk1_k20_dev_init(struct device *dev)
 	apalis_tk1_k20->irq_chip.name		= dev_name(dev);
 	apalis_tk1_k20->irq_chip.status_base	= APALIS_TK1_K20_IRQREG;
 	apalis_tk1_k20->irq_chip.mask_base	= APALIS_TK1_K20_MSQREG;
-	apalis_tk1_k20->irq_chip.ack_base	= APALIS_TK1_K20_IRQREG;
+	apalis_tk1_k20->irq_chip.ack_base	= 0;
 	apalis_tk1_k20->irq_chip.irq_reg_stride	= 0;
 	apalis_tk1_k20->irq_chip.num_regs	= APALIS_TK1_K20_IRQ_REG_CNT;
 	apalis_tk1_k20->irq_chip.irqs		= apalis_tk1_k20->irqs;
diff --git a/drivers/net/can/apalis-tk1-k20-can.c b/drivers/net/can/apalis-tk1-k20-can.c
index 22437c48296f..5d0f5d764ceb 100644
--- a/drivers/net/can/apalis-tk1-k20-can.c
+++ b/drivers/net/can/apalis-tk1-k20-can.c
@@ -155,30 +155,11 @@ static void apalis_tk1_k20_can_hw_rx_frame(struct net_device *net, u8 *buf,
 	apalis_tk1_k20_unlock(priv->apalis_tk1_k20);
 }
 
-static u32 apalis_tk1_k20_can_available_rx_frames(struct net_device *net)
-{
-	u32 frame_cnt = 0;
-	struct apalis_tk1_k20_priv *priv = netdev_priv(net);
-	int ret;
-
-	apalis_tk1_k20_lock(priv->apalis_tk1_k20);
-
-	ret = apalis_tk1_k20_reg_read(priv->apalis_tk1_k20,
-				      APALIS_TK1_K20_CAN_IN_BUF_CNT
-				      + APALIS_TK1_K20_CAN_DEV_OFFSET(
-				      priv->pdata->id),	&frame_cnt);
-	apalis_tk1_k20_unlock(priv->apalis_tk1_k20);
-
-	return (ret == 0) ? frame_cnt : 0;
-}
-
 static void apalis_tk1_k20_can_hw_rx(struct net_device *net, int buf_idx)
 {
 	struct apalis_tk1_k20_priv *priv = netdev_priv(net);
 	struct sk_buff *skb;
 	struct can_frame *frame;
-	u8 available_frames = 0;
-	u8 buf[CAN_TRANSFER_BUF_LEN];
 
 	skb = alloc_can_skb(priv->net, &frame);
 	if (!skb) {
@@ -187,14 +168,7 @@ static void apalis_tk1_k20_can_hw_rx(struct net_device *net, int buf_idx)
 		return;
 	}
 
-	available_frames = apalis_tk1_k20_can_available_rx_frames(net);
-
-	while ((available_frames > 0)) {
-		apalis_tk1_k20_can_hw_rx_frame(net, buf, buf_idx);
-		memcpy(&frame->can_id, buf + MB_EID_OFF, MB_EID_LEN);
-		/* Data length */
-		frame->can_dlc = get_can_dlc(buf[MB_DLC_OFF]);
-		memcpy(frame->data, buf + CAN_HEADER_MAX_LEN, frame->can_dlc);
+		apalis_tk1_k20_can_hw_rx_frame(net, (unsigned char *)frame, buf_idx);
 
 		priv->net->stats.rx_packets++;
 		priv->net->stats.rx_bytes += frame->can_dlc;
@@ -202,8 +176,7 @@ static void apalis_tk1_k20_can_hw_rx(struct net_device *net, int buf_idx)
 		can_led_event(priv->net, CAN_LED_EVENT_RX);
 
 		netif_rx_ni(skb);
-		available_frames--;
-	}
+
 }
 
 static netdev_tx_t apalis_tk1_k20_can_hard_start_xmit(struct sk_buff *skb,