Merge patch series "can: m_can: Optimizations for tcan and peripheral chips"

Markus Schneider-Pargmann <msp@baylibre.com> says:

as requested I split the series into two parts. This is the first
parts with simple improvements to reduce the number of SPI transfers.
The second part will be the rest with coalescing support and more
complex optimizations.

Changes since v1: https://lore.kernel.org/all/20221116205308.2996556-1-msp@baylibre.com
- Fixed register ranges
- Added fixes: tag for two patches

Link: https://lore.kernel.org/all/20221206115728.1056014-1-msp@baylibre.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

3 files changed, 100 insertions, 56 deletions

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index be8f4b662f95..8e83d6963d85 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -369,9 +369,14 @@ m_can_txe_fifo_read(struct m_can_classdev *cdev, u32 fgi, u32 offset, u32 *val)
 	return cdev->ops->read_fifo(cdev, addr_offset, val, 1);
 }
 
+static inline bool _m_can_tx_fifo_full(u32 txfqs)
+{
+	return !!(txfqs & TXFQS_TFQF);
+}
+
 static inline bool m_can_tx_fifo_full(struct m_can_classdev *cdev)
 {
-	return !!(m_can_read(cdev, M_CAN_TXFQS) & TXFQS_TFQF);
+	return _m_can_tx_fifo_full(m_can_read(cdev, M_CAN_TXFQS));
 }
 
 static void m_can_config_endisable(struct m_can_classdev *cdev, bool enable)
@@ -472,19 +477,16 @@ static void m_can_receive_skb(struct m_can_classdev *cdev,
 	}
 }
 
-static int m_can_read_fifo(struct net_device *dev, u32 rxfs)
+static int m_can_read_fifo(struct net_device *dev, u32 fgi)
 {
 	struct net_device_stats *stats = &dev->stats;
 	struct m_can_classdev *cdev = netdev_priv(dev);
 	struct canfd_frame *cf;
 	struct sk_buff *skb;
 	struct id_and_dlc fifo_header;
-	u32 fgi;
 	u32 timestamp = 0;
 	int err;
 
-	/* calculate the fifo get index for where to read data */
-	fgi = FIELD_GET(RXFS_FGI_MASK, rxfs);
 	err = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_ID, &fifo_header, 2);
 	if (err)
 		goto out_fail;
@@ -528,9 +530,6 @@ static int m_can_read_fifo(struct net_device *dev, u32 rxfs)
 	}
 	stats->rx_packets++;
 
-	/* acknowledge rx fifo 0 */
-	m_can_write(cdev, M_CAN_RXF0A, fgi);
-
 	timestamp = FIELD_GET(RX_BUF_RXTS_MASK, fifo_header.dlc) << 16;
 
 	m_can_receive_skb(cdev, skb, timestamp);
@@ -549,7 +548,11 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
 	struct m_can_classdev *cdev = netdev_priv(dev);
 	u32 pkts = 0;
 	u32 rxfs;
-	int err;
+	u32 rx_count;
+	u32 fgi;
+	int ack_fgi = -1;
+	int i;
+	int err = 0;
 
 	rxfs = m_can_read(cdev, M_CAN_RXF0S);
 	if (!(rxfs & RXFS_FFL_MASK)) {
@@ -557,16 +560,26 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
 		return 0;
 	}
 
-	while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) {
-		err = m_can_read_fifo(dev, rxfs);
+	rx_count = FIELD_GET(RXFS_FFL_MASK, rxfs);
+	fgi = FIELD_GET(RXFS_FGI_MASK, rxfs);
+
+	for (i = 0; i < rx_count && quota > 0; ++i) {
+		err = m_can_read_fifo(dev, fgi);
 		if (err)
-			return err;
+			break;
 
 		quota--;
 		pkts++;
-		rxfs = m_can_read(cdev, M_CAN_RXF0S);
+		ack_fgi = fgi;
+		fgi = (++fgi >= cdev->mcfg[MRAM_RXF0].num ? 0 : fgi);
 	}
 
+	if (ack_fgi != -1)
+		m_can_write(cdev, M_CAN_RXF0A, ack_fgi);
+
+	if (err)
+		return err;
+
 	return pkts;
 }
 
@@ -900,14 +913,12 @@ static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
 	return work_done;
 }
 
-static int m_can_rx_handler(struct net_device *dev, int quota)
+static int m_can_rx_handler(struct net_device *dev, int quota, u32 irqstatus)
 {
 	struct m_can_classdev *cdev = netdev_priv(dev);
 	int rx_work_or_err;
 	int work_done = 0;
-	u32 irqstatus, psr;
 
-	irqstatus = cdev->irqstatus | m_can_read(cdev, M_CAN_IR);
 	if (!irqstatus)
 		goto end;
 
@@ -932,13 +943,13 @@ static int m_can_rx_handler(struct net_device *dev, int quota)
 		}
 	}
 
-	psr = m_can_read(cdev, M_CAN_PSR);
-
 	if (irqstatus & IR_ERR_STATE)
-		work_done += m_can_handle_state_errors(dev, psr);
+		work_done += m_can_handle_state_errors(dev,
+						       m_can_read(cdev, M_CAN_PSR));
 
 	if (irqstatus & IR_ERR_BUS_30X)
-		work_done += m_can_handle_bus_errors(dev, irqstatus, psr);
+		work_done += m_can_handle_bus_errors(dev, irqstatus,
+						     m_can_read(cdev, M_CAN_PSR));
 
 	if (irqstatus & IR_RF0N) {
 		rx_work_or_err = m_can_do_rx_poll(dev, (quota - work_done));
@@ -951,12 +962,12 @@ end:
 	return work_done;
 }
 
-static int m_can_rx_peripheral(struct net_device *dev)
+static int m_can_rx_peripheral(struct net_device *dev, u32 irqstatus)
 {
 	struct m_can_classdev *cdev = netdev_priv(dev);
 	int work_done;
 
-	work_done = m_can_rx_handler(dev, NAPI_POLL_WEIGHT);
+	work_done = m_can_rx_handler(dev, NAPI_POLL_WEIGHT, irqstatus);
 
 	/* Don't re-enable interrupts if the driver had a fatal error
 	 * (e.g., FIFO read failure).
@@ -972,8 +983,11 @@ static int m_can_poll(struct napi_struct *napi, int quota)
 	struct net_device *dev = napi->dev;
 	struct m_can_classdev *cdev = netdev_priv(dev);
 	int work_done;
+	u32 irqstatus;
+
+	irqstatus = cdev->irqstatus | m_can_read(cdev, M_CAN_IR);
 
-	work_done = m_can_rx_handler(dev, quota);
+	work_done = m_can_rx_handler(dev, quota, irqstatus);
 
 	/* Don't re-enable interrupts if the driver had a fatal error
 	 * (e.g., FIFO read failure).
@@ -1014,7 +1028,9 @@ static int m_can_echo_tx_event(struct net_device *dev)
 	u32 txe_count = 0;
 	u32 m_can_txefs;
 	u32 fgi = 0;
+	int ack_fgi = -1;
 	int i = 0;
+	int err = 0;
 	unsigned int msg_mark;
 
 	struct m_can_classdev *cdev = netdev_priv(dev);
@@ -1024,34 +1040,34 @@ static int m_can_echo_tx_event(struct net_device *dev)
 
 	/* Get Tx Event fifo element count */
 	txe_count = FIELD_GET(TXEFS_EFFL_MASK, m_can_txefs);
+	fgi = FIELD_GET(TXEFS_EFGI_MASK, m_can_txefs);
 
 	/* Get and process all sent elements */
 	for (i = 0; i < txe_count; i++) {
 		u32 txe, timestamp = 0;
-		int err;
-
-		/* retrieve get index */
-		fgi = FIELD_GET(TXEFS_EFGI_MASK, m_can_read(cdev, M_CAN_TXEFS));
 
 		/* get message marker, timestamp */
 		err = m_can_txe_fifo_read(cdev, fgi, 4, &txe);
 		if (err) {
 			netdev_err(dev, "TXE FIFO read returned %d\n", err);
-			return err;
+			break;
 		}
 
 		msg_mark = FIELD_GET(TX_EVENT_MM_MASK, txe);
 		timestamp = FIELD_GET(TX_EVENT_TXTS_MASK, txe) << 16;
 
-		/* ack txe element */
-		m_can_write(cdev, M_CAN_TXEFA, FIELD_PREP(TXEFA_EFAI_MASK,
-							  fgi));
+		ack_fgi = fgi;
+		fgi = (++fgi >= cdev->mcfg[MRAM_TXE].num ? 0 : fgi);
 
 		/* update stats */
 		m_can_tx_update_stats(cdev, msg_mark, timestamp);
 	}
 
-	return 0;
+	if (ack_fgi != -1)
+		m_can_write(cdev, M_CAN_TXEFA, FIELD_PREP(TXEFA_EFAI_MASK,
+							  ack_fgi));
+
+	return err;
 }
 
 static irqreturn_t m_can_isr(int irq, void *dev_id)
@@ -1083,7 +1099,7 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 		m_can_disable_all_interrupts(cdev);
 		if (!cdev->is_peripheral)
 			napi_schedule(&cdev->napi);
-		else if (m_can_rx_peripheral(dev) < 0)
+		else if (m_can_rx_peripheral(dev, ir) < 0)
 			goto out_fail;
 	}
 
@@ -1609,6 +1625,7 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 	struct sk_buff *skb = cdev->tx_skb;
 	struct id_and_dlc fifo_header;
 	u32 cccr, fdflags;
+	u32 txfqs;
 	int err;
 	int putidx;
 
@@ -1665,8 +1682,10 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 	} else {
 		/* Transmit routine for version >= v3.1.x */
 
+		txfqs = m_can_read(cdev, M_CAN_TXFQS);
+
 		/* Check if FIFO full */
-		if (m_can_tx_fifo_full(cdev)) {
+		if (_m_can_tx_fifo_full(txfqs)) {
 			/* This shouldn't happen */
 			netif_stop_queue(dev);
 			netdev_warn(dev,
@@ -1682,8 +1701,7 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 		}
 
 		/* get put index for frame */
-		putidx = FIELD_GET(TXFQS_TFQPI_MASK,
-				   m_can_read(cdev, M_CAN_TXFQS));
+		putidx = FIELD_GET(TXFQS_TFQPI_MASK, txfqs);
 
 		/* Construct DLC Field, with CAN-FD configuration.
 		 * Use the put index of the fifo as the message marker,
diff --git a/drivers/net/can/m_can/tcan4x5x-core.c b/drivers/net/can/m_can/tcan4x5x-core.c
index a3aeb83de152..2342aa011647 100644
--- a/drivers/net/can/m_can/tcan4x5x-core.c
+++ b/drivers/net/can/m_can/tcan4x5x-core.c
@@ -10,7 +10,7 @@
 #define TCAN4X5X_DEV_ID1 0x04
 #define TCAN4X5X_REV 0x08
 #define TCAN4X5X_STATUS 0x0C
-#define TCAN4X5X_ERROR_STATUS 0x10
+#define TCAN4X5X_ERROR_STATUS_MASK 0x10
 #define TCAN4X5X_CONTROL 0x14
 
 #define TCAN4X5X_CONFIG 0x800
@@ -204,17 +204,7 @@ static int tcan4x5x_clear_interrupts(struct m_can_classdev *cdev)
 	if (ret)
 		return ret;
 
-	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_MCAN_INT_REG,
-				      TCAN4X5X_ENABLE_MCAN_INT);
-	if (ret)
-		return ret;
-
-	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_FLAGS,
-				      TCAN4X5X_CLEAR_ALL_INT);
-	if (ret)
-		return ret;
-
-	return tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS,
+	return tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_FLAGS,
 				       TCAN4X5X_CLEAR_ALL_INT);
 }
 
@@ -234,6 +224,11 @@ static int tcan4x5x_init(struct m_can_classdev *cdev)
 	if (ret)
 		return ret;
 
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS_MASK,
+				      TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return ret;
+
 	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
 				 TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
 	if (ret)
diff --git a/drivers/net/can/m_can/tcan4x5x-regmap.c b/drivers/net/can/m_can/tcan4x5x-regmap.c
index 26e212b8ca7a..2b218ce04e9f 100644
--- a/drivers/net/can/m_can/tcan4x5x-regmap.c
+++ b/drivers/net/can/m_can/tcan4x5x-regmap.c
@@ -90,16 +90,47 @@ static int tcan4x5x_regmap_read(void *context,
 	return 0;
 }
 
-static const struct regmap_range tcan4x5x_reg_table_yes_range[] = {
-	regmap_reg_range(0x0000, 0x002c),	/* Device ID and SPI Registers */
-	regmap_reg_range(0x0800, 0x083c),	/* Device configuration registers and Interrupt Flags*/
+static const struct regmap_range tcan4x5x_reg_table_wr_range[] = {
+	/* Device ID and SPI Registers */
+	regmap_reg_range(0x000c, 0x0010),
+	/* Device configuration registers and Interrupt Flags*/
+	regmap_reg_range(0x0800, 0x080c),
+	regmap_reg_range(0x0814, 0x0814),
+	regmap_reg_range(0x0820, 0x0820),
+	regmap_reg_range(0x0830, 0x0830),
+	/* M_CAN */
+	regmap_reg_range(0x100c, 0x102c),
+	regmap_reg_range(0x1048, 0x1048),
+	regmap_reg_range(0x1050, 0x105c),
+	regmap_reg_range(0x1080, 0x1088),
+	regmap_reg_range(0x1090, 0x1090),
+	regmap_reg_range(0x1098, 0x10a0),
+	regmap_reg_range(0x10a8, 0x10b0),
+	regmap_reg_range(0x10b8, 0x10c0),
+	regmap_reg_range(0x10c8, 0x10c8),
+	regmap_reg_range(0x10d0, 0x10d4),
+	regmap_reg_range(0x10e0, 0x10e4),
+	regmap_reg_range(0x10f0, 0x10f0),
+	regmap_reg_range(0x10f8, 0x10f8),
+	/* MRAM */
+	regmap_reg_range(0x8000, 0x87fc),
+};
+
+static const struct regmap_range tcan4x5x_reg_table_rd_range[] = {
+	regmap_reg_range(0x0000, 0x0010),	/* Device ID and SPI Registers */
+	regmap_reg_range(0x0800, 0x0830),	/* Device configuration registers and Interrupt Flags*/
 	regmap_reg_range(0x1000, 0x10fc),	/* M_CAN */
 	regmap_reg_range(0x8000, 0x87fc),	/* MRAM */
 };
 
-static const struct regmap_access_table tcan4x5x_reg_table = {
-	.yes_ranges = tcan4x5x_reg_table_yes_range,
-	.n_yes_ranges = ARRAY_SIZE(tcan4x5x_reg_table_yes_range),
+static const struct regmap_access_table tcan4x5x_reg_table_wr = {
+	.yes_ranges = tcan4x5x_reg_table_wr_range,
+	.n_yes_ranges = ARRAY_SIZE(tcan4x5x_reg_table_wr_range),
+};
+
+static const struct regmap_access_table tcan4x5x_reg_table_rd = {
+	.yes_ranges = tcan4x5x_reg_table_rd_range,
+	.n_yes_ranges = ARRAY_SIZE(tcan4x5x_reg_table_rd_range),
 };
 
 static const struct regmap_config tcan4x5x_regmap = {
@@ -107,8 +138,8 @@ static const struct regmap_config tcan4x5x_regmap = {
 	.reg_stride = 4,
 	.pad_bits = 8,
 	.val_bits = 32,
-	.wr_table = &tcan4x5x_reg_table,
-	.rd_table = &tcan4x5x_reg_table,
+	.wr_table = &tcan4x5x_reg_table_wr,
+	.rd_table = &tcan4x5x_reg_table_rd,
 	.max_register = TCAN4X5X_MAX_REGISTER,
 	.cache_type = REGCACHE_NONE,
 	.read_flag_mask = (__force unsigned long)