[PATCH v4 1/2] can: holt_hi311x: document device tree bindings

[PATCH v4 1/2] can: holt_hi311x: document device tree bindings

[Akshay Bhat]

Document the HOLT HI-311x CAN device tree bindings.

Signed-off-by: Akshay Bhat <nodeax@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
---

v3 -> v4:
- No changes

 .../devicetree/bindings/net/can/holt_hi311x.txt    | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/can/holt_hi311x.txt

diff --git a/Documentation/devicetree/bindings/net/can/holt_hi311x.txt b/Documentation/devicetree/bindings/net/can/holt_hi311x.txt
new file mode 100644
index 0000000..23aa94e
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/can/holt_hi311x.txt
@@ -0,0 +1,24 @@
+* Holt HI-311X stand-alone CAN controller device tree bindings
+
+Required properties:
+ - compatible: Should be one of the following:
+   - "holt,hi3110" for HI-3110
+ - reg: SPI chip select.
+ - clocks: The clock feeding the CAN controller.
+ - interrupt-parent: The parent interrupt controller.
+ - interrupts: Should contain IRQ line for the CAN controller.
+
+Optional properties:
+ - vdd-supply: Regulator that powers the CAN controller.
+ - xceiver-supply: Regulator that powers the CAN transceiver.
+
+Example:
+	can0: can@1 {
+		compatible = "holt,hi3110";
+		reg = <1>;
+		clocks = <&clk32m>;
+		interrupt-parent = <&gpio4>;
+		interrupts = <13 IRQ_TYPE_EDGE_RISING>;
+		vdd-supply = <&reg5v0>;
+		xceiver-supply = <&reg5v0>;
+	};
-- 
2.8.1

[PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Akshay Bhat]

This patch adds support for the Holt HI-311x CAN controller. The HI311x
CAN controller is capable of transmitting and receiving standard data
frames, extended data frames and remote frames. The HI311x interfaces
with the host over SPI.

Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do

Signed-off-by: Akshay Bhat <nodeax@gmail.com>
---

v3 -> v4:
Address comments from Wolfgang Grandegger:
- Add support for CAN warning state reporting
- Add support for reporting tx/rx error counts in bus error messages
- Keep bus error interrupts enabled to detect CAN state changes
- Fix bug in restart code after BUSOFF state
- Clean up error handling code

 drivers/net/can/spi/Kconfig  |    6 +
 drivers/net/can/spi/Makefile |    1 +
 drivers/net/can/spi/hi311x.c | 1072 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1079 insertions(+)
 create mode 100644 drivers/net/can/spi/hi311x.c

diff --git a/drivers/net/can/spi/Kconfig b/drivers/net/can/spi/Kconfig
index 148cae5..8f2e0dd 100644
--- a/drivers/net/can/spi/Kconfig
+++ b/drivers/net/can/spi/Kconfig
@@ -1,6 +1,12 @@
 menu "CAN SPI interfaces"
 	depends on SPI
 
+config CAN_HI311X
+	tristate "Holt HI311x SPI CAN controllers"
+	depends on CAN_DEV && SPI && HAS_DMA
+	---help---
+	  Driver for the Holt HI311x SPI CAN controllers.
+
 config CAN_MCP251X
 	tristate "Microchip MCP251x SPI CAN controllers"
 	depends on HAS_DMA
diff --git a/drivers/net/can/spi/Makefile b/drivers/net/can/spi/Makefile
index 0e86040..f59fa37 100644
--- a/drivers/net/can/spi/Makefile
+++ b/drivers/net/can/spi/Makefile
@@ -3,4 +3,5 @@
 #
 
 
+obj-$(CONFIG_CAN_HI311X)	+= hi311x.o
 obj-$(CONFIG_CAN_MCP251X)	+= mcp251x.o
diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
new file mode 100644
index 0000000..2a3d794
--- /dev/null
+++ b/drivers/net/can/spi/hi311x.c
@@ -0,0 +1,1072 @@
+/* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
+ *
+ * Copyright(C) Timesys Corporation 2016
+ *
+ * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
+ * Copyright 2009 Christian Pellegrin EVOL S.r.l.
+ * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
+ * Copyright 2006 Arcom Control Systems Ltd.
+ *
+ * Based on CAN bus driver for the CCAN controller written by
+ * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
+ * - Simon Kallweit, intefo AG
+ * Copyright 2007
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/can/core.h>
+#include <linux/can/dev.h>
+#include <linux/can/led.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/freezer.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/uaccess.h>
+
+#define HI3110_MASTER_RESET 0x56
+#define HI3110_READ_CTRL0 0xD2
+#define HI3110_READ_CTRL1 0xD4
+#define HI3110_READ_STATF 0xE2
+#define HI3110_WRITE_CTRL0 0x14
+#define HI3110_WRITE_CTRL1 0x16
+#define HI3110_WRITE_INTE 0x1C
+#define HI3110_WRITE_BTR0 0x18
+#define HI3110_WRITE_BTR1 0x1A
+#define HI3110_READ_BTR0 0xD6
+#define HI3110_READ_BTR1 0xD8
+#define HI3110_READ_INTF 0xDE
+#define HI3110_READ_ERR 0xDC
+#define HI3110_READ_FIFO_WOTIME 0x48
+#define HI3110_WRITE_FIFO 0x12
+#define HI3110_READ_MESSTAT 0xDA
+#define HI3110_READ_REC 0xEA
+#define HI3110_READ_TEC 0xEC
+
+#define HI3110_CTRL0_MODE_MASK (7 << 5)
+#define HI3110_CTRL0_NORMAL_MODE (0 << 5)
+#define HI3110_CTRL0_LOOPBACK_MODE (1 << 5)
+#define HI3110_CTRL0_MONITOR_MODE (2 << 5)
+#define HI3110_CTRL0_SLEEP_MODE (3 << 5)
+#define HI3110_CTRL0_INIT_MODE (4 << 5)
+
+#define HI3110_CTRL1_TXEN BIT(7)
+
+#define HI3110_INT_RXTMP BIT(7)
+#define HI3110_INT_RXFIFO BIT(6)
+#define HI3110_INT_TXCPLT BIT(5)
+#define HI3110_INT_BUSERR BIT(4)
+#define HI3110_INT_MCHG BIT(3)
+#define HI3110_INT_WAKEUP BIT(2)
+#define HI3110_INT_F1MESS BIT(1)
+#define HI3110_INT_F0MESS BIT(0)
+
+#define HI3110_ERR_BUSOFF BIT(7)
+#define HI3110_ERR_TXERRP BIT(6)
+#define HI3110_ERR_RXERRP BIT(5)
+#define HI3110_ERR_BITERR BIT(4)
+#define HI3110_ERR_FRMERR BIT(3)
+#define HI3110_ERR_CRCERR BIT(2)
+#define HI3110_ERR_ACKERR BIT(1)
+#define HI3110_ERR_STUFERR BIT(0)
+#define HI3110_ERR_PROTOCOL_MASK (0x1F)
+#define HI3110_ERR_PASSIVE_MASK (0x60)
+
+#define HI3110_STAT_RXFMTY BIT(1)
+#define HI3110_STAT_BUSOFF BIT(2)
+#define HI3110_STAT_ERRP BIT(3)
+#define HI3110_STAT_ERRW BIT(4)
+
+#define HI3110_BTR0_SJW_SHIFT 6
+#define HI3110_BTR0_BRP_SHIFT 0
+
+#define HI3110_BTR1_SAMP_3PERBIT (1 << 7)
+#define HI3110_BTR1_SAMP_1PERBIT (0 << 7)
+#define HI3110_BTR1_TSEG2_SHIFT 4
+#define HI3110_BTR1_TSEG1_SHIFT 0
+
+#define HI3110_FIFO_WOTIME_TAG_OFF 0
+#define HI3110_FIFO_WOTIME_ID_OFF 1
+#define HI3110_FIFO_WOTIME_DLC_OFF 5
+#define HI3110_FIFO_WOTIME_DAT_OFF 6
+
+#define HI3110_FIFO_WOTIME_TAG_IDE BIT(7)
+#define HI3110_FIFO_WOTIME_ID_RTR BIT(0)
+
+#define HI3110_FIFO_TAG_OFF 0
+#define HI3110_FIFO_ID_OFF 1
+#define HI3110_FIFO_STD_DLC_OFF 3
+#define HI3110_FIFO_STD_DATA_OFF 4
+#define HI3110_FIFO_EXT_DLC_OFF 5
+#define HI3110_FIFO_EXT_DATA_OFF 6
+
+#define HI3110_CAN_MAX_DATA_LEN 8
+#define HI3110_RX_BUF_LEN 15
+#define HI3110_TX_STD_BUF_LEN 12
+#define HI3110_TX_EXT_BUF_LEN 14
+#define HI3110_CAN_FRAME_MAX_BITS 128
+#define HI3110_EFF_FLAGS 0x18 /* IDE + SRR */
+
+#define HI3110_TX_ECHO_SKB_MAX 1
+
+#define HI3110_OST_DELAY_MS (10)
+
+#define DEVICE_NAME "hi3110"
+
+static int hi3110_enable_dma = 1; /* Enable SPI DMA. Default: 1 (On) */
+module_param(hi3110_enable_dma, int, 0444);
+MODULE_PARM_DESC(hi3110_enable_dma, "Enable SPI DMA. Default: 1 (On)");
+
+static const struct can_bittiming_const hi3110_bittiming_const = {
+	.name = DEVICE_NAME,
+	.tseg1_min = 2,
+	.tseg1_max = 16,
+	.tseg2_min = 2,
+	.tseg2_max = 8,
+	.sjw_max = 4,
+	.brp_min = 1,
+	.brp_max = 64,
+	.brp_inc = 1,
+};
+
+enum hi3110_model {
+	CAN_HI3110_HI3110 = 0x3110,
+};
+
+struct hi3110_priv {
+	struct can_priv can;
+	struct net_device *net;
+	struct spi_device *spi;
+	enum hi3110_model model;
+
+	struct mutex hi3110_lock; /* SPI device lock */
+
+	u8 *spi_tx_buf;
+	u8 *spi_rx_buf;
+	dma_addr_t spi_tx_dma;
+	dma_addr_t spi_rx_dma;
+
+	struct sk_buff *tx_skb;
+	int tx_len;
+
+	struct workqueue_struct *wq;
+	struct work_struct tx_work;
+	struct work_struct restart_work;
+
+	int force_quit;
+	int after_suspend;
+#define HI3110_AFTER_SUSPEND_UP 1
+#define HI3110_AFTER_SUSPEND_DOWN 2
+#define HI3110_AFTER_SUSPEND_POWER 4
+#define HI3110_AFTER_SUSPEND_RESTART 8
+	int restart_tx;
+	struct regulator *power;
+	struct regulator *transceiver;
+	struct clk *clk;
+};
+
+static void hi3110_clean(struct net_device *net)
+{
+	struct hi3110_priv *priv = netdev_priv(net);
+
+	if (priv->tx_skb || priv->tx_len)
+		net->stats.tx_errors++;
+	if (priv->tx_skb)
+		dev_kfree_skb(priv->tx_skb);
+	if (priv->tx_len)
+		can_free_echo_skb(priv->net, 0);
+	priv->tx_skb = NULL;
+	priv->tx_len = 0;
+}
+
+/* Note about handling of error return of hi3110_spi_trans: accessing
+ * registers via SPI is not really different conceptually than using
+ * normal I/O assembler instructions, although it's much more
+ * complicated from a practical POV. So it's not advisable to always
+ * check the return value of this function. Imagine that every
+ * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
+ * error();", it would be a great mess (well there are some situation
+ * when exception handling C++ like could be useful after all). So we
+ * just check that transfers are OK at the beginning of our
+ * conversation with the chip and to avoid doing really nasty things
+ * (like injecting bogus packets in the network stack).
+ */
+static int hi3110_spi_trans(struct spi_device *spi, int len)
+{
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+	struct spi_transfer t = {
+		.tx_buf = priv->spi_tx_buf,
+		.rx_buf = priv->spi_rx_buf,
+		.len = len,
+		.cs_change = 0,
+	};
+	struct spi_message m;
+	int ret;
+
+	spi_message_init(&m);
+
+	if (hi3110_enable_dma) {
+		t.tx_dma = priv->spi_tx_dma;
+		t.rx_dma = priv->spi_rx_dma;
+		m.is_dma_mapped = 1;
+	}
+
+	spi_message_add_tail(&t, &m);
+
+	ret = spi_sync(spi, &m);
+
+	if (ret)
+		dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
+	return ret;
+}
+
+static u8 hi3110_cmd(struct spi_device *spi, u8 command)
+{
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+
+	priv->spi_tx_buf[0] = command;
+	dev_dbg(&spi->dev, "hi3110_cmd: %02X\n", command);
+
+	return hi3110_spi_trans(spi, 1);
+}
+
+static u8 hi3110_read(struct spi_device *spi, u8 command)
+{
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+	u8 val = 0;
+
+	priv->spi_tx_buf[0] = command;
+	hi3110_spi_trans(spi, 2);
+	val = priv->spi_rx_buf[1];
+
+	return val;
+}
+
+static void hi3110_write(struct spi_device *spi, u8 reg, u8 val)
+{
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+
+	priv->spi_tx_buf[0] = reg;
+	priv->spi_tx_buf[1] = val;
+	hi3110_spi_trans(spi, 2);
+}
+
+static void hi3110_hw_tx_frame(struct spi_device *spi, u8 *buf, int len)
+{
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+
+	priv->spi_tx_buf[0] = HI3110_WRITE_FIFO;
+	memcpy(priv->spi_tx_buf + 1, buf, len);
+	hi3110_spi_trans(spi, len + 1);
+}
+
+static void hi3110_hw_tx(struct spi_device *spi, struct can_frame *frame)
+{
+	u8 buf[HI3110_TX_EXT_BUF_LEN];
+
+	buf[HI3110_FIFO_TAG_OFF] = 0;
+
+	if (frame->can_id & CAN_EFF_FLAG) {
+		/* Extended frame */
+		buf[HI3110_FIFO_ID_OFF] = (frame->can_id & CAN_EFF_MASK) >> 21;
+		buf[HI3110_FIFO_ID_OFF + 1] =
+			(((frame->can_id & CAN_EFF_MASK) >> 13) & 0xe0) |
+			HI3110_EFF_FLAGS |
+			(((frame->can_id & CAN_EFF_MASK) >> 15) & 0x07);
+		buf[HI3110_FIFO_ID_OFF + 2] =
+			(frame->can_id & CAN_EFF_MASK) >> 7;
+		buf[HI3110_FIFO_ID_OFF + 3] =
+			((frame->can_id & CAN_EFF_MASK) << 1) |
+			((frame->can_id & CAN_RTR_FLAG) ? 1 : 0);
+
+		buf[HI3110_FIFO_EXT_DLC_OFF] = frame->can_dlc;
+
+		memcpy(buf + HI3110_FIFO_EXT_DATA_OFF,
+		       frame->data, frame->can_dlc);
+
+		hi3110_hw_tx_frame(spi, buf, HI3110_TX_EXT_BUF_LEN -
+				   (HI3110_CAN_MAX_DATA_LEN - frame->can_dlc));
+	} else {
+		/* Standard frame */
+		buf[HI3110_FIFO_ID_OFF] =   (frame->can_id & CAN_SFF_MASK) >> 3;
+		buf[HI3110_FIFO_ID_OFF + 1] =
+			((frame->can_id & CAN_SFF_MASK) << 5) |
+			((frame->can_id & CAN_RTR_FLAG) ? (1 << 4) : 0);
+
+		buf[HI3110_FIFO_STD_DLC_OFF] = frame->can_dlc;
+
+		memcpy(buf + HI3110_FIFO_STD_DATA_OFF,
+		       frame->data, frame->can_dlc);
+
+		hi3110_hw_tx_frame(spi, buf, HI3110_TX_STD_BUF_LEN -
+				   (HI3110_CAN_MAX_DATA_LEN - frame->can_dlc));
+	}
+}
+
+static void hi3110_hw_rx_frame(struct spi_device *spi, u8 *buf)
+{
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+
+	priv->spi_tx_buf[0] = HI3110_READ_FIFO_WOTIME;
+	hi3110_spi_trans(spi, HI3110_RX_BUF_LEN);
+	memcpy(buf, priv->spi_rx_buf + 1, HI3110_RX_BUF_LEN - 1);
+}
+
+static void hi3110_hw_rx(struct spi_device *spi)
+{
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+	struct sk_buff *skb;
+	struct can_frame *frame;
+	u8 buf[HI3110_RX_BUF_LEN - 1];
+
+	skb = alloc_can_skb(priv->net, &frame);
+	if (!skb) {
+		priv->net->stats.rx_dropped++;
+		return;
+	}
+
+	hi3110_hw_rx_frame(spi, buf);
+	if (buf[HI3110_FIFO_WOTIME_TAG_OFF] & HI3110_FIFO_WOTIME_TAG_IDE) {
+		/* IDE is recessive (1), indicating extended 29-bit frame */
+		frame->can_id = CAN_EFF_FLAG;
+		frame->can_id |=
+		 (buf[HI3110_FIFO_WOTIME_ID_OFF] << 21) |
+		 (((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5) << 18) |
+		 ((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0x07) << 15) |
+		 (buf[HI3110_FIFO_WOTIME_ID_OFF + 2] << 7) |
+		 (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] >> 1);
+	} else {
+		/* IDE is dominant (0), frame indicating standard 11-bit */
+		frame->can_id =
+			(buf[HI3110_FIFO_WOTIME_ID_OFF] << 3) |
+			((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5);
+	}
+
+	/* Data length */
+	frame->can_dlc = get_can_dlc(buf[HI3110_FIFO_WOTIME_DLC_OFF] & 0x0F);
+
+	if (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] & HI3110_FIFO_WOTIME_ID_RTR)
+		frame->can_id |= CAN_RTR_FLAG;
+	else
+		memcpy(frame->data, buf + HI3110_FIFO_WOTIME_DAT_OFF,
+		       frame->can_dlc);
+
+	priv->net->stats.rx_packets++;
+	priv->net->stats.rx_bytes += frame->can_dlc;
+
+	can_led_event(priv->net, CAN_LED_EVENT_RX);
+
+	netif_rx_ni(skb);
+}
+
+static void hi3110_hw_sleep(struct spi_device *spi)
+{
+	hi3110_write(spi, HI3110_WRITE_CTRL0, HI3110_CTRL0_SLEEP_MODE);
+}
+
+static netdev_tx_t hi3110_hard_start_xmit(struct sk_buff *skb,
+					  struct net_device *net)
+{
+	struct hi3110_priv *priv = netdev_priv(net);
+	struct spi_device *spi = priv->spi;
+
+	if (priv->tx_skb || priv->tx_len) {
+		dev_err(&spi->dev, "hard_xmit called while tx busy\n");
+		return NETDEV_TX_BUSY;
+	}
+
+	if (can_dropped_invalid_skb(net, skb))
+		return NETDEV_TX_OK;
+
+	netif_stop_queue(net);
+	priv->tx_skb = skb;
+	queue_work(priv->wq, &priv->tx_work);
+
+	return NETDEV_TX_OK;
+}
+
+static int hi3110_do_set_mode(struct net_device *net, enum can_mode mode)
+{
+	struct hi3110_priv *priv = netdev_priv(net);
+
+	switch (mode) {
+	case CAN_MODE_START:
+		hi3110_clean(net);
+		/* We have to delay work since SPI I/O may sleep */
+		priv->can.state = CAN_STATE_ERROR_ACTIVE;
+		priv->restart_tx = 1;
+		if (priv->can.restart_ms == 0)
+			priv->after_suspend = HI3110_AFTER_SUSPEND_RESTART;
+		queue_work(priv->wq, &priv->restart_work);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int hi3110_get_berr_counter(const struct net_device *net,
+				   struct can_berr_counter *bec)
+{
+	struct hi3110_priv *priv = netdev_priv(net);
+	struct spi_device *spi = priv->spi;
+
+	bec->txerr = hi3110_read(spi, HI3110_READ_TEC);
+	bec->rxerr = hi3110_read(spi, HI3110_READ_REC);
+
+	return 0;
+}
+
+static int hi3110_set_normal_mode(struct spi_device *spi)
+{
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+	u8 reg = 0;
+
+	hi3110_write(spi, HI3110_WRITE_INTE, HI3110_INT_BUSERR |
+		     HI3110_INT_RXFIFO | HI3110_INT_TXCPLT);
+
+	/* Enable TX */
+	hi3110_write(spi, HI3110_WRITE_CTRL1, HI3110_CTRL1_TXEN);
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
+		reg = HI3110_CTRL0_LOOPBACK_MODE;
+	else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
+		reg = HI3110_CTRL0_MONITOR_MODE;
+	else
+		reg = HI3110_CTRL0_NORMAL_MODE;
+
+	hi3110_write(spi, HI3110_WRITE_CTRL0, reg);
+
+	/* Wait for the device to enter the mode */
+	mdelay(HI3110_OST_DELAY_MS);
+	reg = hi3110_read(spi, HI3110_READ_CTRL0);
+	if ((reg & HI3110_CTRL0_MODE_MASK) != reg)
+		return -EBUSY;
+
+	priv->can.state = CAN_STATE_ERROR_ACTIVE;
+	return 0;
+}
+
+static int hi3110_do_set_bittiming(struct net_device *net)
+{
+	struct hi3110_priv *priv = netdev_priv(net);
+	struct can_bittiming *bt = &priv->can.bittiming;
+	struct spi_device *spi = priv->spi;
+
+	hi3110_write(spi, HI3110_WRITE_BTR0,
+		     ((bt->sjw - 1) << HI3110_BTR0_SJW_SHIFT) |
+		     ((bt->brp - 1) << HI3110_BTR0_BRP_SHIFT));
+
+	hi3110_write(spi, HI3110_WRITE_BTR1,
+		     (priv->can.ctrlmode &
+		     CAN_CTRLMODE_3_SAMPLES ?
+		     HI3110_BTR1_SAMP_3PERBIT : HI3110_BTR1_SAMP_1PERBIT) |
+		     ((bt->phase_seg1 + bt->prop_seg - 1)
+		     << HI3110_BTR1_TSEG1_SHIFT) |
+		     ((bt->phase_seg2 - 1) << HI3110_BTR1_TSEG2_SHIFT));
+
+	dev_dbg(&spi->dev, "BT: 0x%02x 0x%02x\n",
+		hi3110_read(spi, HI3110_READ_BTR0),
+		hi3110_read(spi, HI3110_READ_BTR1));
+
+	return 0;
+}
+
+static int hi3110_setup(struct net_device *net)
+{
+	hi3110_do_set_bittiming(net);
+	return 0;
+}
+
+static int hi3110_hw_reset(struct spi_device *spi)
+{
+	u8 reg;
+	int ret;
+
+	/* Wait for oscillator startup timer after power up */
+	mdelay(HI3110_OST_DELAY_MS);
+
+	ret = hi3110_cmd(spi, HI3110_MASTER_RESET);
+	if (ret)
+		return ret;
+
+	/* Wait for oscillator startup timer after reset */
+	mdelay(HI3110_OST_DELAY_MS);
+
+	reg = hi3110_read(spi, HI3110_READ_CTRL0);
+	if ((reg & HI3110_CTRL0_MODE_MASK) != HI3110_CTRL0_INIT_MODE)
+		return -ENODEV;
+
+	/* As per the datasheet it appears the error flags are
+	 * not cleared on reset. Explicitly clear them by performing a read
+	 */
+	hi3110_read(spi, HI3110_READ_ERR);
+
+	return 0;
+}
+
+static int hi3110_hw_probe(struct spi_device *spi)
+{
+	u8 statf;
+
+	hi3110_hw_reset(spi);
+
+	/* Confirm correct operation by checking against reset values
+	 * in datasheet
+	 */
+	statf = hi3110_read(spi, HI3110_READ_STATF);
+
+	dev_dbg(&spi->dev, "statf: %02X\n", statf);
+
+	if (statf != 0x82)
+		return -ENODEV;
+
+	return 0;
+}
+
+static int hi3110_power_enable(struct regulator *reg, int enable)
+{
+	if (IS_ERR_OR_NULL(reg))
+		return 0;
+
+	if (enable)
+		return regulator_enable(reg);
+	else
+		return regulator_disable(reg);
+}
+
+static int hi3110_stop(struct net_device *net)
+{
+	struct hi3110_priv *priv = netdev_priv(net);
+	struct spi_device *spi = priv->spi;
+
+	close_candev(net);
+
+	priv->force_quit = 1;
+	free_irq(spi->irq, priv);
+	destroy_workqueue(priv->wq);
+	priv->wq = NULL;
+
+	mutex_lock(&priv->hi3110_lock);
+
+	/* Disable transmit, interrupts and clear flags */
+	hi3110_write(spi, HI3110_WRITE_CTRL1, 0x0);
+	hi3110_write(spi, HI3110_WRITE_INTE, 0x0);
+	hi3110_read(spi, HI3110_READ_INTF);
+
+	hi3110_clean(net);
+
+	hi3110_hw_sleep(spi);
+
+	hi3110_power_enable(priv->transceiver, 0);
+
+	priv->can.state = CAN_STATE_STOPPED;
+
+	mutex_unlock(&priv->hi3110_lock);
+
+	can_led_event(net, CAN_LED_EVENT_STOP);
+
+	return 0;
+}
+
+static void hi3110_tx_work_handler(struct work_struct *ws)
+{
+	struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
+						 tx_work);
+	struct spi_device *spi = priv->spi;
+	struct net_device *net = priv->net;
+	struct can_frame *frame;
+
+	mutex_lock(&priv->hi3110_lock);
+	if (priv->tx_skb) {
+		if (priv->can.state == CAN_STATE_BUS_OFF) {
+			hi3110_clean(net);
+		} else {
+			frame = (struct can_frame *)priv->tx_skb->data;
+			hi3110_hw_tx(spi, frame);
+			priv->tx_len = 1 + frame->can_dlc;
+			can_put_echo_skb(priv->tx_skb, net, 0);
+			priv->tx_skb = NULL;
+		}
+	}
+	mutex_unlock(&priv->hi3110_lock);
+}
+
+static void hi3110_restart_work_handler(struct work_struct *ws)
+{
+	struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
+						 restart_work);
+	struct spi_device *spi = priv->spi;
+	struct net_device *net = priv->net;
+
+	mutex_lock(&priv->hi3110_lock);
+	if (priv->after_suspend) {
+		hi3110_hw_reset(spi);
+		hi3110_setup(net);
+		if (priv->after_suspend & HI3110_AFTER_SUSPEND_RESTART) {
+			hi3110_set_normal_mode(spi);
+		} else if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
+			netif_device_attach(net);
+			hi3110_clean(net);
+			hi3110_set_normal_mode(spi);
+			netif_wake_queue(net);
+		} else {
+			hi3110_hw_sleep(spi);
+		}
+		priv->after_suspend = 0;
+		priv->force_quit = 0;
+	}
+
+	if (priv->restart_tx) {
+		priv->restart_tx = 0;
+		hi3110_hw_reset(spi);
+		hi3110_setup(net);
+		hi3110_clean(net);
+		hi3110_set_normal_mode(spi);
+		netif_wake_queue(net);
+	}
+	mutex_unlock(&priv->hi3110_lock);
+}
+
+static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
+{
+	struct hi3110_priv *priv = dev_id;
+	struct spi_device *spi = priv->spi;
+	struct net_device *net = priv->net;
+
+	mutex_lock(&priv->hi3110_lock);
+
+	while (!priv->force_quit) {
+		enum can_state new_state;
+		u8 intf, eflag, statf;
+
+		while (!(HI3110_STAT_RXFMTY &
+		       (statf = hi3110_read(spi, HI3110_READ_STATF)))) {
+			hi3110_hw_rx(spi);
+		}
+
+		intf = hi3110_read(spi, HI3110_READ_INTF);
+		eflag = hi3110_read(spi, HI3110_READ_ERR);
+		/* Update can state */
+		if (eflag & HI3110_ERR_BUSOFF)
+			new_state = CAN_STATE_BUS_OFF;
+		else if (eflag & HI3110_ERR_PASSIVE_MASK)
+			new_state = CAN_STATE_ERROR_PASSIVE;
+		else if (statf & HI3110_STAT_ERRW)
+			new_state = CAN_STATE_ERROR_WARNING;
+		else
+			new_state = CAN_STATE_ERROR_ACTIVE;
+
+		if (new_state != priv->can.state) {
+			struct can_frame *cf;
+			struct sk_buff *skb;
+			enum can_state rx_state, tx_state;
+			u8 rxerr, txerr;
+
+			skb = alloc_can_err_skb(net, &cf);
+			if (!skb)
+				break;
+
+			txerr = hi3110_read(spi, HI3110_READ_TEC);
+			rxerr = hi3110_read(spi, HI3110_READ_REC);
+			cf->data[6] = txerr;
+			cf->data[7] = rxerr;
+			tx_state = txerr >= rxerr ? new_state : 0;
+			rx_state = txerr <= rxerr ? new_state : 0;
+			can_change_state(net, cf, tx_state, rx_state);
+			netif_rx_ni(skb);
+
+			if (new_state == CAN_STATE_BUS_OFF) {
+				can_bus_off(net);
+				if (priv->can.restart_ms == 0) {
+					priv->force_quit = 1;
+					hi3110_hw_sleep(spi);
+					break;
+				}
+			}
+		}
+
+		/* Update bus errors */
+		if ((intf & HI3110_INT_BUSERR) &&
+		    (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
+			struct can_frame *cf;
+			struct sk_buff *skb;
+
+			/* Check for protocol errors */
+			if (eflag & HI3110_ERR_PROTOCOL_MASK) {
+				skb = alloc_can_err_skb(net, &cf);
+				if (!skb)
+					break;
+
+				cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+				priv->can.can_stats.bus_error++;
+				priv->net->stats.rx_errors++;
+				if (eflag & HI3110_ERR_BITERR)
+					cf->data[2] |= CAN_ERR_PROT_BIT;
+				else if (eflag & HI3110_ERR_FRMERR)
+					cf->data[2] |= CAN_ERR_PROT_FORM;
+				else if (eflag & HI3110_ERR_STUFERR)
+					cf->data[2] |= CAN_ERR_PROT_STUFF;
+				else if (eflag & HI3110_ERR_CRCERR)
+					cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+				else if (eflag & HI3110_ERR_ACKERR)
+					cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
+
+				cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);
+				cf->data[7] = hi3110_read(spi, HI3110_READ_REC);
+				netdev_dbg(priv->net, "Bus Error\n");
+				netif_rx_ni(skb);
+			}
+		}
+
+		if (intf == 0)
+			break;
+
+		if (intf & HI3110_INT_TXCPLT) {
+			net->stats.tx_packets++;
+			net->stats.tx_bytes += priv->tx_len - 1;
+			can_led_event(net, CAN_LED_EVENT_TX);
+			if (priv->tx_len) {
+				can_get_echo_skb(net, 0);
+				priv->tx_len = 0;
+			}
+			netif_wake_queue(net);
+		}
+	}
+	mutex_unlock(&priv->hi3110_lock);
+	return IRQ_HANDLED;
+}
+
+static int hi3110_open(struct net_device *net)
+{
+	struct hi3110_priv *priv = netdev_priv(net);
+	struct spi_device *spi = priv->spi;
+	unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_RISING;
+	int ret;
+
+	ret = open_candev(net);
+	if (ret)
+		return ret;
+
+	mutex_lock(&priv->hi3110_lock);
+	hi3110_power_enable(priv->transceiver, 1);
+
+	priv->force_quit = 0;
+	priv->tx_skb = NULL;
+	priv->tx_len = 0;
+
+	ret = request_threaded_irq(spi->irq, NULL, hi3110_can_ist,
+				   flags, DEVICE_NAME, priv);
+	if (ret) {
+		dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
+		goto out_close;
+	}
+
+	priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
+			   0);
+	INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);
+	INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);
+
+	ret = hi3110_hw_reset(spi);
+	if (ret)
+		goto out_free_irq;
+
+	ret = hi3110_setup(net);
+	if (ret)
+		goto out_free_irq;
+
+	ret = hi3110_set_normal_mode(spi);
+	if (ret)
+		goto out_free_irq;
+
+	can_led_event(net, CAN_LED_EVENT_OPEN);
+	netif_wake_queue(net);
+	mutex_unlock(&priv->hi3110_lock);
+
+	return 0;
+
+out_free_irq:
+	free_irq(spi->irq, priv);
+	hi3110_hw_sleep(spi);
+
+out_close:
+	hi3110_power_enable(priv->transceiver, 0);
+	close_candev(net);
+	mutex_unlock(&priv->hi3110_lock);
+	return ret;
+}
+
+static const struct net_device_ops hi3110_netdev_ops = {
+	.ndo_open = hi3110_open,
+	.ndo_stop = hi3110_stop,
+	.ndo_start_xmit = hi3110_hard_start_xmit,
+};
+
+static const struct of_device_id hi3110_of_match[] = {
+	{
+		.compatible	= "holt,hi3110",
+		.data		= (void *)CAN_HI3110_HI3110,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, hi3110_of_match);
+
+static const struct spi_device_id hi3110_id_table[] = {
+	{
+		.name		= "hi3110",
+		.driver_data	= (kernel_ulong_t)CAN_HI3110_HI3110,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, hi3110_id_table);
+
+static int hi3110_can_probe(struct spi_device *spi)
+{
+	const struct of_device_id *of_id = of_match_device(hi3110_of_match,
+							   &spi->dev);
+	struct net_device *net;
+	struct hi3110_priv *priv;
+	struct clk *clk;
+	int freq, ret;
+
+	clk = devm_clk_get(&spi->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&spi->dev, "no CAN clock source defined\n");
+		return PTR_ERR(clk);
+	}
+	freq = clk_get_rate(clk);
+
+	/* Sanity check */
+	if (freq > 40000000)
+		return -ERANGE;
+
+	/* Allocate can/net device */
+	net = alloc_candev(sizeof(struct hi3110_priv), HI3110_TX_ECHO_SKB_MAX);
+	if (!net)
+		return -ENOMEM;
+
+	if (!IS_ERR(clk)) {
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			goto out_free;
+	}
+
+	net->netdev_ops = &hi3110_netdev_ops;
+	net->flags |= IFF_ECHO;
+
+	priv = netdev_priv(net);
+	priv->can.bittiming_const = &hi3110_bittiming_const;
+	priv->can.do_set_mode = hi3110_do_set_mode;
+	priv->can.do_get_berr_counter = hi3110_get_berr_counter;
+	priv->can.clock.freq = freq / 2;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
+				       CAN_CTRLMODE_LOOPBACK |
+				       CAN_CTRLMODE_LISTENONLY |
+				       CAN_CTRLMODE_BERR_REPORTING;
+
+	if (of_id)
+		priv->model = (enum hi3110_model)of_id->data;
+	else
+		priv->model = spi_get_device_id(spi)->driver_data;
+	priv->net = net;
+	priv->clk = clk;
+
+	spi_set_drvdata(spi, priv);
+
+	/* Configure the SPI bus */
+	spi->bits_per_word = 8;
+	ret = spi_setup(spi);
+	if (ret)
+		goto out_clk;
+
+	priv->power = devm_regulator_get_optional(&spi->dev, "vdd");
+	priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
+	if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
+	    (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
+		ret = -EPROBE_DEFER;
+		goto out_clk;
+	}
+
+	ret = hi3110_power_enable(priv->power, 1);
+	if (ret)
+		goto out_clk;
+
+	priv->spi = spi;
+	mutex_init(&priv->hi3110_lock);
+
+	/* If requested, allocate DMA buffers */
+	if (hi3110_enable_dma) {
+		spi->dev.coherent_dma_mask = ~0;
+
+		/* Minimum coherent DMA allocation is PAGE_SIZE, so allocate
+		 * that much and share it between Tx and Rx DMA buffers.
+		 */
+		priv->spi_tx_buf = dmam_alloc_coherent(&spi->dev,
+						      PAGE_SIZE,
+						      &priv->spi_tx_dma,
+						      GFP_DMA);
+
+		if (priv->spi_tx_buf) {
+			priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
+			priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
+							(PAGE_SIZE / 2));
+		} else {
+			/* Fall back to non-DMA */
+			hi3110_enable_dma = 0;
+		}
+	}
+
+	/* Allocate non-DMA buffers */
+	if (!hi3110_enable_dma) {
+		priv->spi_tx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
+				GFP_KERNEL);
+		if (!priv->spi_tx_buf) {
+			ret = -ENOMEM;
+			goto error_probe;
+		}
+		priv->spi_rx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
+				GFP_KERNEL);
+
+		if (!priv->spi_rx_buf) {
+			ret = -ENOMEM;
+			goto error_probe;
+		}
+	}
+
+	SET_NETDEV_DEV(net, &spi->dev);
+
+	ret = hi3110_hw_probe(spi);
+	if (ret) {
+		if (ret == -ENODEV)
+			dev_err(&spi->dev, "Cannot initialize %x. Wrong wiring?\n",
+				priv->model);
+		goto error_probe;
+	}
+	hi3110_hw_sleep(spi);
+
+	ret = register_candev(net);
+	if (ret)
+		goto error_probe;
+
+	devm_can_led_init(net);
+	netdev_info(net, "%x successfully initialized.\n", priv->model);
+
+	return 0;
+
+error_probe:
+	hi3110_power_enable(priv->power, 0);
+
+out_clk:
+	if (!IS_ERR(clk))
+		clk_disable_unprepare(clk);
+
+out_free:
+	free_candev(net);
+
+	dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
+	return ret;
+}
+
+static int hi3110_can_remove(struct spi_device *spi)
+{
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+	struct net_device *net = priv->net;
+
+	unregister_candev(net);
+
+	hi3110_power_enable(priv->power, 0);
+
+	if (!IS_ERR(priv->clk))
+		clk_disable_unprepare(priv->clk);
+
+	free_candev(net);
+
+	return 0;
+}
+
+static int __maybe_unused hi3110_can_suspend(struct device *dev)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+	struct net_device *net = priv->net;
+
+	priv->force_quit = 1;
+	disable_irq(spi->irq);
+
+	/* Note: at this point neither IST nor workqueues are running.
+	 * open/stop cannot be called anyway so locking is not needed
+	 */
+	if (netif_running(net)) {
+		netif_device_detach(net);
+
+		hi3110_hw_sleep(spi);
+		hi3110_power_enable(priv->transceiver, 0);
+		priv->after_suspend = HI3110_AFTER_SUSPEND_UP;
+	} else {
+		priv->after_suspend = HI3110_AFTER_SUSPEND_DOWN;
+	}
+
+	if (!IS_ERR_OR_NULL(priv->power)) {
+		regulator_disable(priv->power);
+		priv->after_suspend |= HI3110_AFTER_SUSPEND_POWER;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused hi3110_can_resume(struct device *dev)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct hi3110_priv *priv = spi_get_drvdata(spi);
+
+	if (priv->after_suspend & HI3110_AFTER_SUSPEND_POWER)
+		hi3110_power_enable(priv->power, 1);
+
+	if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
+		hi3110_power_enable(priv->transceiver, 1);
+		queue_work(priv->wq, &priv->restart_work);
+	} else {
+		priv->after_suspend = 0;
+	}
+
+	priv->force_quit = 0;
+	enable_irq(spi->irq);
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(hi3110_can_pm_ops, hi3110_can_suspend,
+	hi3110_can_resume);
+
+static struct spi_driver hi3110_can_driver = {
+	.driver = {
+		.name = DEVICE_NAME,
+		.of_match_table = hi3110_of_match,
+		.pm = &hi3110_can_pm_ops,
+	},
+	.id_table = hi3110_id_table,
+	.probe = hi3110_can_probe,
+	.remove = hi3110_can_remove,
+};
+
+module_spi_driver(hi3110_can_driver);
+
+MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
+MODULE_AUTHOR("Casey Fitzpatrick <casey.fitzpatrick@timesys.com>");
+MODULE_DESCRIPTION("Holt HI-3110 CAN driver");
+MODULE_LICENSE("GPL v2");
-- 
2.8.1

Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Wolfgang Grandegger]

Hello Akshay,

I still see some improvements...

Am 17.03.2017 um 22:10 schrieb Akshay Bhat:
> This patch adds support for the Holt HI-311x CAN controller. The HI311x
> CAN controller is capable of transmitting and receiving standard data
> frames, extended data frames and remote frames. The HI311x interfaces
> with the host over SPI.
>
> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
>
> Signed-off-by: Akshay Bhat <nodeax-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>
> v3 -> v4:
> Address comments from Wolfgang Grandegger:
> - Add support for CAN warning state reporting
> - Add support for reporting tx/rx error counts in bus error messages
> - Keep bus error interrupts enabled to detect CAN state changes
> - Fix bug in restart code after BUSOFF state
> - Clean up error handling code
>
>  drivers/net/can/spi/Kconfig  |    6 +
>  drivers/net/can/spi/Makefile |    1 +
>  drivers/net/can/spi/hi311x.c | 1072 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1079 insertions(+)
>  create mode 100644 drivers/net/can/spi/hi311x.c
>
> diff --git a/drivers/net/can/spi/Kconfig b/drivers/net/can/spi/Kconfig
> index 148cae5..8f2e0dd 100644
> --- a/drivers/net/can/spi/Kconfig
> +++ b/drivers/net/can/spi/Kconfig
> @@ -1,6 +1,12 @@
>  menu "CAN SPI interfaces"
>  	depends on SPI
>
> +config CAN_HI311X
> +	tristate "Holt HI311x SPI CAN controllers"
> +	depends on CAN_DEV && SPI && HAS_DMA
> +	---help---
> +	  Driver for the Holt HI311x SPI CAN controllers.
> +
>  config CAN_MCP251X
>  	tristate "Microchip MCP251x SPI CAN controllers"
>  	depends on HAS_DMA
> diff --git a/drivers/net/can/spi/Makefile b/drivers/net/can/spi/Makefile
> index 0e86040..f59fa37 100644
> --- a/drivers/net/can/spi/Makefile
> +++ b/drivers/net/can/spi/Makefile
> @@ -3,4 +3,5 @@
>  #
>
>
> +obj-$(CONFIG_CAN_HI311X)	+= hi311x.o
>  obj-$(CONFIG_CAN_MCP251X)	+= mcp251x.o
> diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
> new file mode 100644
> index 0000000..2a3d794
> --- /dev/null
> +++ b/drivers/net/can/spi/hi311x.c
> @@ -0,0 +1,1072 @@
> +/* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
> + *
> + * Copyright(C) Timesys Corporation 2016
> + *
> + * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
> + * Copyright 2009 Christian Pellegrin EVOL S.r.l.
> + * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
> + * Copyright 2006 Arcom Control Systems Ltd.
> + *
> + * Based on CAN bus driver for the CCAN controller written by
> + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
> + * - Simon Kallweit, intefo AG
> + * Copyright 2007
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */

... snip...

> +
> +static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
> +{
> +	struct hi3110_priv *priv = dev_id;
> +	struct spi_device *spi = priv->spi;
> +	struct net_device *net = priv->net;
> +
> +	mutex_lock(&priv->hi3110_lock);
> +
> +	while (!priv->force_quit) {
> +		enum can_state new_state;
> +		u8 intf, eflag, statf;
> +
> +		while (!(HI3110_STAT_RXFMTY &
> +		       (statf = hi3110_read(spi, HI3110_READ_STATF)))) {
> +			hi3110_hw_rx(spi);
> +		}
> +
> +		intf = hi3110_read(spi, HI3110_READ_INTF);

I think HI3110_READ_ERR is only valid if HI3110_INT_BUSERR is set! 
Therefore:

                 if ((intf & HI3110_INT_BUSERR) {

It saves reading one SPI register in the message processing path. Please 
check if back-to-error-active still comes.

> +		eflag = hi3110_read(spi, HI3110_READ_ERR);
> +		/* Update can state */
> +		if (eflag & HI3110_ERR_BUSOFF)
> +			new_state = CAN_STATE_BUS_OFF;
> +		else if (eflag & HI3110_ERR_PASSIVE_MASK)
> +			new_state = CAN_STATE_ERROR_PASSIVE;
> +		else if (statf & HI3110_STAT_ERRW)
> +			new_state = CAN_STATE_ERROR_WARNING;
> +		else
> +			new_state = CAN_STATE_ERROR_ACTIVE;
> +
> +		if (new_state != priv->can.state) {
> +			struct can_frame *cf;
> +			struct sk_buff *skb;
> +			enum can_state rx_state, tx_state;
> +			u8 rxerr, txerr;
> +
> +			skb = alloc_can_err_skb(net, &cf);
> +			if (!skb)
> +				break;
> +
> +			txerr = hi3110_read(spi, HI3110_READ_TEC);
> +			rxerr = hi3110_read(spi, HI3110_READ_REC);
> +			cf->data[6] = txerr;
> +			cf->data[7] = rxerr;
> +			tx_state = txerr >= rxerr ? new_state : 0;
> +			rx_state = txerr <= rxerr ? new_state : 0;
> +			can_change_state(net, cf, tx_state, rx_state);
> +			netif_rx_ni(skb);
> +
> +			if (new_state == CAN_STATE_BUS_OFF) {
> +				can_bus_off(net);
> +				if (priv->can.restart_ms == 0) {
> +					priv->force_quit = 1;
> +					hi3110_hw_sleep(spi);
> +					break;
> +				}
> +			}
> +		}
> +
> +		/* Update bus errors */
> +		if ((intf & HI3110_INT_BUSERR) &&
> +		    (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
> +			struct can_frame *cf;
> +			struct sk_buff *skb;
> +
> +			/* Check for protocol errors */
> +			if (eflag & HI3110_ERR_PROTOCOL_MASK) {
> +				skb = alloc_can_err_skb(net, &cf);
> +				if (!skb)
> +					break;
> +
> +				cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> +				priv->can.can_stats.bus_error++;
> +				priv->net->stats.rx_errors++;
> +				if (eflag & HI3110_ERR_BITERR)
> +					cf->data[2] |= CAN_ERR_PROT_BIT;
> +				else if (eflag & HI3110_ERR_FRMERR)
> +					cf->data[2] |= CAN_ERR_PROT_FORM;
> +				else if (eflag & HI3110_ERR_STUFERR)
> +					cf->data[2] |= CAN_ERR_PROT_STUFF;
> +				else if (eflag & HI3110_ERR_CRCERR)
> +					cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
> +				else if (eflag & HI3110_ERR_ACKERR)
> +					cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
> +
> +				cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);
> +				cf->data[7] = hi3110_read(spi, HI3110_READ_REC);
> +				netdev_dbg(priv->net, "Bus Error\n");
> +				netif_rx_ni(skb);
> +			}
> +		}
> +
> +		if (intf == 0)
> +			break;

I do not see a real benefit of the check above. Just more code.

> +		if (intf & HI3110_INT_TXCPLT) {
> +			net->stats.tx_packets++;
> +			net->stats.tx_bytes += priv->tx_len - 1;
> +			can_led_event(net, CAN_LED_EVENT_TX);
> +			if (priv->tx_len) {
> +				can_get_echo_skb(net, 0);
> +				priv->tx_len = 0;
> +			}
> +			netif_wake_queue(net);
> +		}
> +	}
> +	mutex_unlock(&priv->hi3110_lock);
> +	return IRQ_HANDLED;
> +}

Apart from that, it looks good now and you can add my:

Acked-by: Wolfgang Grandegger <wg-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>

Thanks,

Wolfgang.


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Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Wolfgang Grandegger]

Hello Akshay,

I still see some improvements...

Am 17.03.2017 um 22:10 schrieb Akshay Bhat:
> This patch adds support for the Holt HI-311x CAN controller. The HI311x
> CAN controller is capable of transmitting and receiving standard data
> frames, extended data frames and remote frames. The HI311x interfaces
> with the host over SPI.
>
> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
>
> Signed-off-by: Akshay Bhat <nodeax@gmail.com>
> ---
>
> v3 -> v4:
> Address comments from Wolfgang Grandegger:
> - Add support for CAN warning state reporting
> - Add support for reporting tx/rx error counts in bus error messages
> - Keep bus error interrupts enabled to detect CAN state changes
> - Fix bug in restart code after BUSOFF state
> - Clean up error handling code
>
>  drivers/net/can/spi/Kconfig  |    6 +
>  drivers/net/can/spi/Makefile |    1 +
>  drivers/net/can/spi/hi311x.c | 1072 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1079 insertions(+)
>  create mode 100644 drivers/net/can/spi/hi311x.c
>
> diff --git a/drivers/net/can/spi/Kconfig b/drivers/net/can/spi/Kconfig
> index 148cae5..8f2e0dd 100644
> --- a/drivers/net/can/spi/Kconfig
> +++ b/drivers/net/can/spi/Kconfig
> @@ -1,6 +1,12 @@
>  menu "CAN SPI interfaces"
>  	depends on SPI
>
> +config CAN_HI311X
> +	tristate "Holt HI311x SPI CAN controllers"
> +	depends on CAN_DEV && SPI && HAS_DMA
> +	---help---
> +	  Driver for the Holt HI311x SPI CAN controllers.
> +
>  config CAN_MCP251X
>  	tristate "Microchip MCP251x SPI CAN controllers"
>  	depends on HAS_DMA
> diff --git a/drivers/net/can/spi/Makefile b/drivers/net/can/spi/Makefile
> index 0e86040..f59fa37 100644
> --- a/drivers/net/can/spi/Makefile
> +++ b/drivers/net/can/spi/Makefile
> @@ -3,4 +3,5 @@
>  #
>
>
> +obj-$(CONFIG_CAN_HI311X)	+= hi311x.o
>  obj-$(CONFIG_CAN_MCP251X)	+= mcp251x.o
> diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
> new file mode 100644
> index 0000000..2a3d794
> --- /dev/null
> +++ b/drivers/net/can/spi/hi311x.c
> @@ -0,0 +1,1072 @@
> +/* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
> + *
> + * Copyright(C) Timesys Corporation 2016
> + *
> + * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
> + * Copyright 2009 Christian Pellegrin EVOL S.r.l.
> + * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
> + * Copyright 2006 Arcom Control Systems Ltd.
> + *
> + * Based on CAN bus driver for the CCAN controller written by
> + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
> + * - Simon Kallweit, intefo AG
> + * Copyright 2007
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */

... snip...

> +
> +static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
> +{
> +	struct hi3110_priv *priv = dev_id;
> +	struct spi_device *spi = priv->spi;
> +	struct net_device *net = priv->net;
> +
> +	mutex_lock(&priv->hi3110_lock);
> +
> +	while (!priv->force_quit) {
> +		enum can_state new_state;
> +		u8 intf, eflag, statf;
> +
> +		while (!(HI3110_STAT_RXFMTY &
> +		       (statf = hi3110_read(spi, HI3110_READ_STATF)))) {
> +			hi3110_hw_rx(spi);
> +		}
> +
> +		intf = hi3110_read(spi, HI3110_READ_INTF);

I think HI3110_READ_ERR is only valid if HI3110_INT_BUSERR is set! 
Therefore:

                 if ((intf & HI3110_INT_BUSERR) {

It saves reading one SPI register in the message processing path. Please 
check if back-to-error-active still comes.

> +		eflag = hi3110_read(spi, HI3110_READ_ERR);
> +		/* Update can state */
> +		if (eflag & HI3110_ERR_BUSOFF)
> +			new_state = CAN_STATE_BUS_OFF;
> +		else if (eflag & HI3110_ERR_PASSIVE_MASK)
> +			new_state = CAN_STATE_ERROR_PASSIVE;
> +		else if (statf & HI3110_STAT_ERRW)
> +			new_state = CAN_STATE_ERROR_WARNING;
> +		else
> +			new_state = CAN_STATE_ERROR_ACTIVE;
> +
> +		if (new_state != priv->can.state) {
> +			struct can_frame *cf;
> +			struct sk_buff *skb;
> +			enum can_state rx_state, tx_state;
> +			u8 rxerr, txerr;
> +
> +			skb = alloc_can_err_skb(net, &cf);
> +			if (!skb)
> +				break;
> +
> +			txerr = hi3110_read(spi, HI3110_READ_TEC);
> +			rxerr = hi3110_read(spi, HI3110_READ_REC);
> +			cf->data[6] = txerr;
> +			cf->data[7] = rxerr;
> +			tx_state = txerr >= rxerr ? new_state : 0;
> +			rx_state = txerr <= rxerr ? new_state : 0;
> +			can_change_state(net, cf, tx_state, rx_state);
> +			netif_rx_ni(skb);
> +
> +			if (new_state == CAN_STATE_BUS_OFF) {
> +				can_bus_off(net);
> +				if (priv->can.restart_ms == 0) {
> +					priv->force_quit = 1;
> +					hi3110_hw_sleep(spi);
> +					break;
> +				}
> +			}
> +		}
> +
> +		/* Update bus errors */
> +		if ((intf & HI3110_INT_BUSERR) &&
> +		    (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
> +			struct can_frame *cf;
> +			struct sk_buff *skb;
> +
> +			/* Check for protocol errors */
> +			if (eflag & HI3110_ERR_PROTOCOL_MASK) {
> +				skb = alloc_can_err_skb(net, &cf);
> +				if (!skb)
> +					break;
> +
> +				cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> +				priv->can.can_stats.bus_error++;
> +				priv->net->stats.rx_errors++;
> +				if (eflag & HI3110_ERR_BITERR)
> +					cf->data[2] |= CAN_ERR_PROT_BIT;
> +				else if (eflag & HI3110_ERR_FRMERR)
> +					cf->data[2] |= CAN_ERR_PROT_FORM;
> +				else if (eflag & HI3110_ERR_STUFERR)
> +					cf->data[2] |= CAN_ERR_PROT_STUFF;
> +				else if (eflag & HI3110_ERR_CRCERR)
> +					cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
> +				else if (eflag & HI3110_ERR_ACKERR)
> +					cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
> +
> +				cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);
> +				cf->data[7] = hi3110_read(spi, HI3110_READ_REC);
> +				netdev_dbg(priv->net, "Bus Error\n");
> +				netif_rx_ni(skb);
> +			}
> +		}
> +
> +		if (intf == 0)
> +			break;

I do not see a real benefit of the check above. Just more code.

> +		if (intf & HI3110_INT_TXCPLT) {
> +			net->stats.tx_packets++;
> +			net->stats.tx_bytes += priv->tx_len - 1;
> +			can_led_event(net, CAN_LED_EVENT_TX);
> +			if (priv->tx_len) {
> +				can_get_echo_skb(net, 0);
> +				priv->tx_len = 0;
> +			}
> +			netif_wake_queue(net);
> +		}
> +	}
> +	mutex_unlock(&priv->hi3110_lock);
> +	return IRQ_HANDLED;
> +}

Apart from that, it looks good now and you can add my:

Acked-by: Wolfgang Grandegger <wg@grandegger.com>

Thanks,

Wolfgang.

Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Akshay Bhat]

Hi Wolfgang,

On 03/19/2017 12:17 PM, Wolfgang Grandegger wrote:
> Hello Akshay,
> 
> I still see some improvements...
> 
> Am 17.03.2017 um 22:10 schrieb Akshay Bhat:
>> This patch adds support for the Holt HI-311x CAN controller. The HI311x
>> CAN controller is capable of transmitting and receiving standard data
>> frames, extended data frames and remote frames. The HI311x interfaces
>> with the host over SPI.
>>
>> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
>>
>> Signed-off-by: Akshay Bhat <nodeax-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> ---
>>
>> v3 -> v4:
>> Address comments from Wolfgang Grandegger:
>> - Add support for CAN warning state reporting
>> - Add support for reporting tx/rx error counts in bus error messages
>> - Keep bus error interrupts enabled to detect CAN state changes
>> - Fix bug in restart code after BUSOFF state
>> - Clean up error handling code
>>
>>  drivers/net/can/spi/Kconfig  |    6 +
>>  drivers/net/can/spi/Makefile |    1 +
>>  drivers/net/can/spi/hi311x.c | 1072
>> ++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 1079 insertions(+)
>>  create mode 100644 drivers/net/can/spi/hi311x.c
>>
>> diff --git a/drivers/net/can/spi/Kconfig b/drivers/net/can/spi/Kconfig
>> index 148cae5..8f2e0dd 100644
>> --- a/drivers/net/can/spi/Kconfig
>> +++ b/drivers/net/can/spi/Kconfig
>> @@ -1,6 +1,12 @@
>>  menu "CAN SPI interfaces"
>>      depends on SPI
>>
>> +config CAN_HI311X
>> +    tristate "Holt HI311x SPI CAN controllers"
>> +    depends on CAN_DEV && SPI && HAS_DMA
>> +    ---help---
>> +      Driver for the Holt HI311x SPI CAN controllers.
>> +
>>  config CAN_MCP251X
>>      tristate "Microchip MCP251x SPI CAN controllers"
>>      depends on HAS_DMA
>> diff --git a/drivers/net/can/spi/Makefile b/drivers/net/can/spi/Makefile
>> index 0e86040..f59fa37 100644
>> --- a/drivers/net/can/spi/Makefile
>> +++ b/drivers/net/can/spi/Makefile
>> @@ -3,4 +3,5 @@
>>  #
>>
>>
>> +obj-$(CONFIG_CAN_HI311X)    += hi311x.o
>>  obj-$(CONFIG_CAN_MCP251X)    += mcp251x.o
>> diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
>> new file mode 100644
>> index 0000000..2a3d794
>> --- /dev/null
>> +++ b/drivers/net/can/spi/hi311x.c
>> @@ -0,0 +1,1072 @@
>> +/* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
>> + *
>> + * Copyright(C) Timesys Corporation 2016
>> + *
>> + * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
>> + * Copyright 2009 Christian Pellegrin EVOL S.r.l.
>> + * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
>> + * Copyright 2006 Arcom Control Systems Ltd.
>> + *
>> + * Based on CAN bus driver for the CCAN controller written by
>> + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
>> + * - Simon Kallweit, intefo AG
>> + * Copyright 2007
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
> 
> ... snip...
> 
>> +
>> +static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
>> +{
>> +    struct hi3110_priv *priv = dev_id;
>> +    struct spi_device *spi = priv->spi;
>> +    struct net_device *net = priv->net;
>> +
>> +    mutex_lock(&priv->hi3110_lock);
>> +
>> +    while (!priv->force_quit) {
>> +        enum can_state new_state;
>> +        u8 intf, eflag, statf;
>> +
>> +        while (!(HI3110_STAT_RXFMTY &
>> +               (statf = hi3110_read(spi, HI3110_READ_STATF)))) {
>> +            hi3110_hw_rx(spi);
>> +        }
>> +
>> +        intf = hi3110_read(spi, HI3110_READ_INTF);
> 
> I think HI3110_READ_ERR is only valid if HI3110_INT_BUSERR is set!
> Therefore:
> 
>                 if ((intf & HI3110_INT_BUSERR) {
> 
> It saves reading one SPI register in the message processing path. Please
> check if back-to-error-active still comes.
> 

The top 3 bits of HI3110_READ_ERR (BUSOFF, TXERRP, RXERRP) are valid
even if HI3110_INT_BUSERR is not set.

To find out the bus state the options are:
1. Rely on HI3110_READ_ERR (BUSOFF, TXERRP, RXERRP)
2. Rely on HI3110_READ_STATF (ERRW, ERRP and BUSOFF bits)

When using HI3110_READ_STATF, I ran into a chip quirk where the status
bits (ERRW, ERRP and BUSOFF) do not change in an atomic manner.

So what would *sometimes* happen on a cable disconnect (based on
interrupt timing) is there is a spurious "back-to-error-active":
 (000.213777)  can0  20000004   [8]  00 08 00 00 00 00 60 00   ERRORFRAME
        controller-problem{tx-error-warning}
        error-counter-tx-rx{{96}{0}}
 (000.004760)  can0  20000004   [8]  00 40 00 00 00 00 80 00   ERRORFRAME
        controller-problem{back-to-error-active}
        error-counter-tx-rx{{128}{0}}
 (000.000338)  can0  20000004   [8]  00 20 00 00 00 00 80 00   ERRORFRAME
        controller-problem{tx-error-passive}
        error-counter-tx-rx{{128}{0}}

Adding a printk to print the intf/statf register values in the ISR
changed the timing and made the issue go away. However using
trace_printk the chip quirk was captured.

On cable disconnect, HI3110_READ_STATF register goes from 0x32 (ERRW) =>
0x22 (No error) => 0x2a (ERRP) instead of going from 0x32 (ERRW) => 0x2a
(ERRP)

147.216878: hi3110_can_ist: can_ist: intf: 0x10, statf 0x32, eflag 0x2
147.217060: hi3110_can_ist: can_ist: intf: 0x0, statf 0x32, eflag 0x0
147.218107: hi3110_can_ist: can_ist: intf: 0x10, statf 0x22, eflag 0x42
147.218453: hi3110_can_ist: can_ist: intf: 0x0, statf 0x2a, eflag 0x40

This issue does not exist if HI3110_READ_ERR is used instead. Hence I
would recommend always doing the extra "HI3110_READ_ERR" spi read to get
around the chip quirk.


>> +        eflag = hi3110_read(spi, HI3110_READ_ERR);
>> +        /* Update can state */
>> +        if (eflag & HI3110_ERR_BUSOFF)
>> +            new_state = CAN_STATE_BUS_OFF;
>> +        else if (eflag & HI3110_ERR_PASSIVE_MASK)
>> +            new_state = CAN_STATE_ERROR_PASSIVE;
>> +        else if (statf & HI3110_STAT_ERRW)
>> +            new_state = CAN_STATE_ERROR_WARNING;
>> +        else
>> +            new_state = CAN_STATE_ERROR_ACTIVE;
>> +
>> +        if (new_state != priv->can.state) {
>> +            struct can_frame *cf;
>> +            struct sk_buff *skb;
>> +            enum can_state rx_state, tx_state;
>> +            u8 rxerr, txerr;
>> +
>> +            skb = alloc_can_err_skb(net, &cf);
>> +            if (!skb)
>> +                break;
>> +
>> +            txerr = hi3110_read(spi, HI3110_READ_TEC);
>> +            rxerr = hi3110_read(spi, HI3110_READ_REC);
>> +            cf->data[6] = txerr;
>> +            cf->data[7] = rxerr;
>> +            tx_state = txerr >= rxerr ? new_state : 0;
>> +            rx_state = txerr <= rxerr ? new_state : 0;
>> +            can_change_state(net, cf, tx_state, rx_state);
>> +            netif_rx_ni(skb);
>> +
>> +            if (new_state == CAN_STATE_BUS_OFF) {
>> +                can_bus_off(net);
>> +                if (priv->can.restart_ms == 0) {
>> +                    priv->force_quit = 1;
>> +                    hi3110_hw_sleep(spi);
>> +                    break;
>> +                }
>> +            }
>> +        }
>> +
>> +        /* Update bus errors */
>> +        if ((intf & HI3110_INT_BUSERR) &&
>> +            (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
>> +            struct can_frame *cf;
>> +            struct sk_buff *skb;
>> +
>> +            /* Check for protocol errors */
>> +            if (eflag & HI3110_ERR_PROTOCOL_MASK) {
>> +                skb = alloc_can_err_skb(net, &cf);
>> +                if (!skb)
>> +                    break;
>> +
>> +                cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>> +                priv->can.can_stats.bus_error++;
>> +                priv->net->stats.rx_errors++;
>> +                if (eflag & HI3110_ERR_BITERR)
>> +                    cf->data[2] |= CAN_ERR_PROT_BIT;
>> +                else if (eflag & HI3110_ERR_FRMERR)
>> +                    cf->data[2] |= CAN_ERR_PROT_FORM;
>> +                else if (eflag & HI3110_ERR_STUFERR)
>> +                    cf->data[2] |= CAN_ERR_PROT_STUFF;
>> +                else if (eflag & HI3110_ERR_CRCERR)
>> +                    cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
>> +                else if (eflag & HI3110_ERR_ACKERR)
>> +                    cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
>> +
>> +                cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);
>> +                cf->data[7] = hi3110_read(spi, HI3110_READ_REC);
>> +                netdev_dbg(priv->net, "Bus Error\n");
>> +                netif_rx_ni(skb);
>> +            }
>> +        }
>> +
>> +        if (intf == 0)
>> +            break;
> 
> I do not see a real benefit of the check above. Just more code.
> 

This is the only code path (apart from bussoff, restart_ms = 0) where
the ISR exits the while loop. Hence it is necessary.

Thanks,
Akshay
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Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Akshay Bhat]

Hi Wolfgang,

On 03/19/2017 12:17 PM, Wolfgang Grandegger wrote:
> Hello Akshay,
> 
> I still see some improvements...
> 
> Am 17.03.2017 um 22:10 schrieb Akshay Bhat:
>> This patch adds support for the Holt HI-311x CAN controller. The HI311x
>> CAN controller is capable of transmitting and receiving standard data
>> frames, extended data frames and remote frames. The HI311x interfaces
>> with the host over SPI.
>>
>> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
>>
>> Signed-off-by: Akshay Bhat <nodeax@gmail.com>
>> ---
>>
>> v3 -> v4:
>> Address comments from Wolfgang Grandegger:
>> - Add support for CAN warning state reporting
>> - Add support for reporting tx/rx error counts in bus error messages
>> - Keep bus error interrupts enabled to detect CAN state changes
>> - Fix bug in restart code after BUSOFF state
>> - Clean up error handling code
>>
>>  drivers/net/can/spi/Kconfig  |    6 +
>>  drivers/net/can/spi/Makefile |    1 +
>>  drivers/net/can/spi/hi311x.c | 1072
>> ++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 1079 insertions(+)
>>  create mode 100644 drivers/net/can/spi/hi311x.c
>>
>> diff --git a/drivers/net/can/spi/Kconfig b/drivers/net/can/spi/Kconfig
>> index 148cae5..8f2e0dd 100644
>> --- a/drivers/net/can/spi/Kconfig
>> +++ b/drivers/net/can/spi/Kconfig
>> @@ -1,6 +1,12 @@
>>  menu "CAN SPI interfaces"
>>      depends on SPI
>>
>> +config CAN_HI311X
>> +    tristate "Holt HI311x SPI CAN controllers"
>> +    depends on CAN_DEV && SPI && HAS_DMA
>> +    ---help---
>> +      Driver for the Holt HI311x SPI CAN controllers.
>> +
>>  config CAN_MCP251X
>>      tristate "Microchip MCP251x SPI CAN controllers"
>>      depends on HAS_DMA
>> diff --git a/drivers/net/can/spi/Makefile b/drivers/net/can/spi/Makefile
>> index 0e86040..f59fa37 100644
>> --- a/drivers/net/can/spi/Makefile
>> +++ b/drivers/net/can/spi/Makefile
>> @@ -3,4 +3,5 @@
>>  #
>>
>>
>> +obj-$(CONFIG_CAN_HI311X)    += hi311x.o
>>  obj-$(CONFIG_CAN_MCP251X)    += mcp251x.o
>> diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
>> new file mode 100644
>> index 0000000..2a3d794
>> --- /dev/null
>> +++ b/drivers/net/can/spi/hi311x.c
>> @@ -0,0 +1,1072 @@
>> +/* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
>> + *
>> + * Copyright(C) Timesys Corporation 2016
>> + *
>> + * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
>> + * Copyright 2009 Christian Pellegrin EVOL S.r.l.
>> + * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
>> + * Copyright 2006 Arcom Control Systems Ltd.
>> + *
>> + * Based on CAN bus driver for the CCAN controller written by
>> + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
>> + * - Simon Kallweit, intefo AG
>> + * Copyright 2007
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
> 
> ... snip...
> 
>> +
>> +static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
>> +{
>> +    struct hi3110_priv *priv = dev_id;
>> +    struct spi_device *spi = priv->spi;
>> +    struct net_device *net = priv->net;
>> +
>> +    mutex_lock(&priv->hi3110_lock);
>> +
>> +    while (!priv->force_quit) {
>> +        enum can_state new_state;
>> +        u8 intf, eflag, statf;
>> +
>> +        while (!(HI3110_STAT_RXFMTY &
>> +               (statf = hi3110_read(spi, HI3110_READ_STATF)))) {
>> +            hi3110_hw_rx(spi);
>> +        }
>> +
>> +        intf = hi3110_read(spi, HI3110_READ_INTF);
> 
> I think HI3110_READ_ERR is only valid if HI3110_INT_BUSERR is set!
> Therefore:
> 
>                 if ((intf & HI3110_INT_BUSERR) {
> 
> It saves reading one SPI register in the message processing path. Please
> check if back-to-error-active still comes.
> 

The top 3 bits of HI3110_READ_ERR (BUSOFF, TXERRP, RXERRP) are valid
even if HI3110_INT_BUSERR is not set.

To find out the bus state the options are:
1. Rely on HI3110_READ_ERR (BUSOFF, TXERRP, RXERRP)
2. Rely on HI3110_READ_STATF (ERRW, ERRP and BUSOFF bits)

When using HI3110_READ_STATF, I ran into a chip quirk where the status
bits (ERRW, ERRP and BUSOFF) do not change in an atomic manner.

So what would *sometimes* happen on a cable disconnect (based on
interrupt timing) is there is a spurious "back-to-error-active":
 (000.213777)  can0  20000004   [8]  00 08 00 00 00 00 60 00   ERRORFRAME
        controller-problem{tx-error-warning}
        error-counter-tx-rx{{96}{0}}
 (000.004760)  can0  20000004   [8]  00 40 00 00 00 00 80 00   ERRORFRAME
        controller-problem{back-to-error-active}
        error-counter-tx-rx{{128}{0}}
 (000.000338)  can0  20000004   [8]  00 20 00 00 00 00 80 00   ERRORFRAME
        controller-problem{tx-error-passive}
        error-counter-tx-rx{{128}{0}}

Adding a printk to print the intf/statf register values in the ISR
changed the timing and made the issue go away. However using
trace_printk the chip quirk was captured.

On cable disconnect, HI3110_READ_STATF register goes from 0x32 (ERRW) =>
0x22 (No error) => 0x2a (ERRP) instead of going from 0x32 (ERRW) => 0x2a
(ERRP)

147.216878: hi3110_can_ist: can_ist: intf: 0x10, statf 0x32, eflag 0x2
147.217060: hi3110_can_ist: can_ist: intf: 0x0, statf 0x32, eflag 0x0
147.218107: hi3110_can_ist: can_ist: intf: 0x10, statf 0x22, eflag 0x42
147.218453: hi3110_can_ist: can_ist: intf: 0x0, statf 0x2a, eflag 0x40

This issue does not exist if HI3110_READ_ERR is used instead. Hence I
would recommend always doing the extra "HI3110_READ_ERR" spi read to get
around the chip quirk.


>> +        eflag = hi3110_read(spi, HI3110_READ_ERR);
>> +        /* Update can state */
>> +        if (eflag & HI3110_ERR_BUSOFF)
>> +            new_state = CAN_STATE_BUS_OFF;
>> +        else if (eflag & HI3110_ERR_PASSIVE_MASK)
>> +            new_state = CAN_STATE_ERROR_PASSIVE;
>> +        else if (statf & HI3110_STAT_ERRW)
>> +            new_state = CAN_STATE_ERROR_WARNING;
>> +        else
>> +            new_state = CAN_STATE_ERROR_ACTIVE;
>> +
>> +        if (new_state != priv->can.state) {
>> +            struct can_frame *cf;
>> +            struct sk_buff *skb;
>> +            enum can_state rx_state, tx_state;
>> +            u8 rxerr, txerr;
>> +
>> +            skb = alloc_can_err_skb(net, &cf);
>> +            if (!skb)
>> +                break;
>> +
>> +            txerr = hi3110_read(spi, HI3110_READ_TEC);
>> +            rxerr = hi3110_read(spi, HI3110_READ_REC);
>> +            cf->data[6] = txerr;
>> +            cf->data[7] = rxerr;
>> +            tx_state = txerr >= rxerr ? new_state : 0;
>> +            rx_state = txerr <= rxerr ? new_state : 0;
>> +            can_change_state(net, cf, tx_state, rx_state);
>> +            netif_rx_ni(skb);
>> +
>> +            if (new_state == CAN_STATE_BUS_OFF) {
>> +                can_bus_off(net);
>> +                if (priv->can.restart_ms == 0) {
>> +                    priv->force_quit = 1;
>> +                    hi3110_hw_sleep(spi);
>> +                    break;
>> +                }
>> +            }
>> +        }
>> +
>> +        /* Update bus errors */
>> +        if ((intf & HI3110_INT_BUSERR) &&
>> +            (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
>> +            struct can_frame *cf;
>> +            struct sk_buff *skb;
>> +
>> +            /* Check for protocol errors */
>> +            if (eflag & HI3110_ERR_PROTOCOL_MASK) {
>> +                skb = alloc_can_err_skb(net, &cf);
>> +                if (!skb)
>> +                    break;
>> +
>> +                cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>> +                priv->can.can_stats.bus_error++;
>> +                priv->net->stats.rx_errors++;
>> +                if (eflag & HI3110_ERR_BITERR)
>> +                    cf->data[2] |= CAN_ERR_PROT_BIT;
>> +                else if (eflag & HI3110_ERR_FRMERR)
>> +                    cf->data[2] |= CAN_ERR_PROT_FORM;
>> +                else if (eflag & HI3110_ERR_STUFERR)
>> +                    cf->data[2] |= CAN_ERR_PROT_STUFF;
>> +                else if (eflag & HI3110_ERR_CRCERR)
>> +                    cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
>> +                else if (eflag & HI3110_ERR_ACKERR)
>> +                    cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
>> +
>> +                cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);
>> +                cf->data[7] = hi3110_read(spi, HI3110_READ_REC);
>> +                netdev_dbg(priv->net, "Bus Error\n");
>> +                netif_rx_ni(skb);
>> +            }
>> +        }
>> +
>> +        if (intf == 0)
>> +            break;
> 
> I do not see a real benefit of the check above. Just more code.
> 

This is the only code path (apart from bussoff, restart_ms = 0) where
the ISR exits the while loop. Hence it is necessary.

Thanks,
Akshay

Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Wolfgang Grandegger]

Hello Akshay,

Am 20.03.2017 um 16:14 schrieb Akshay Bhat:
> Hi Wolfgang,
>
> On 03/19/2017 12:17 PM, Wolfgang Grandegger wrote:
>> Hello Akshay,
>>
>> I still see some improvements...
>>
>> Am 17.03.2017 um 22:10 schrieb Akshay Bhat:
>>> This patch adds support for the Holt HI-311x CAN controller. The HI311x
>>> CAN controller is capable of transmitting and receiving standard data
>>> frames, extended data frames and remote frames. The HI311x interfaces
>>> with the host over SPI.
>>>
>>> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
>>>
>>> Signed-off-by: Akshay Bhat <nodeax@gmail.com>
>>> ---
>>>
>>> v3 -> v4:
>>> Address comments from Wolfgang Grandegger:
>>> - Add support for CAN warning state reporting
>>> - Add support for reporting tx/rx error counts in bus error messages
>>> - Keep bus error interrupts enabled to detect CAN state changes
>>> - Fix bug in restart code after BUSOFF state
>>> - Clean up error handling code
>>>
>>>  drivers/net/can/spi/Kconfig  |    6 +
>>>  drivers/net/can/spi/Makefile |    1 +
>>>  drivers/net/can/spi/hi311x.c | 1072
>>> ++++++++++++++++++++++++++++++++++++++++++
>>>  3 files changed, 1079 insertions(+)
>>>  create mode 100644 drivers/net/can/spi/hi311x.c
>>>
>>> diff --git a/drivers/net/can/spi/Kconfig b/drivers/net/can/spi/Kconfig
>>> index 148cae5..8f2e0dd 100644
>>> --- a/drivers/net/can/spi/Kconfig
>>> +++ b/drivers/net/can/spi/Kconfig
>>> @@ -1,6 +1,12 @@
>>>  menu "CAN SPI interfaces"
>>>      depends on SPI
>>>
>>> +config CAN_HI311X
>>> +    tristate "Holt HI311x SPI CAN controllers"
>>> +    depends on CAN_DEV && SPI && HAS_DMA
>>> +    ---help---
>>> +      Driver for the Holt HI311x SPI CAN controllers.
>>> +
>>>  config CAN_MCP251X
>>>      tristate "Microchip MCP251x SPI CAN controllers"
>>>      depends on HAS_DMA
>>> diff --git a/drivers/net/can/spi/Makefile b/drivers/net/can/spi/Makefile
>>> index 0e86040..f59fa37 100644
>>> --- a/drivers/net/can/spi/Makefile
>>> +++ b/drivers/net/can/spi/Makefile
>>> @@ -3,4 +3,5 @@
>>>  #
>>>
>>>
>>> +obj-$(CONFIG_CAN_HI311X)    += hi311x.o
>>>  obj-$(CONFIG_CAN_MCP251X)    += mcp251x.o
>>> diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
>>> new file mode 100644
>>> index 0000000..2a3d794
>>> --- /dev/null
>>> +++ b/drivers/net/can/spi/hi311x.c
>>> @@ -0,0 +1,1072 @@
>>> +/* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
>>> + *
>>> + * Copyright(C) Timesys Corporation 2016
>>> + *
>>> + * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
>>> + * Copyright 2009 Christian Pellegrin EVOL S.r.l.
>>> + * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
>>> + * Copyright 2006 Arcom Control Systems Ltd.
>>> + *
>>> + * Based on CAN bus driver for the CCAN controller written by
>>> + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
>>> + * - Simon Kallweit, intefo AG
>>> + * Copyright 2007
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License version 2 as
>>> + * published by the Free Software Foundation.
>>> + */
>>
>> ... snip...
>>
>>> +
>>> +static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
>>> +{
>>> +    struct hi3110_priv *priv = dev_id;
>>> +    struct spi_device *spi = priv->spi;
>>> +    struct net_device *net = priv->net;
>>> +
>>> +    mutex_lock(&priv->hi3110_lock);
>>> +
>>> +    while (!priv->force_quit) {
>>> +        enum can_state new_state;
>>> +        u8 intf, eflag, statf;
>>> +
>>> +        while (!(HI3110_STAT_RXFMTY &
>>> +               (statf = hi3110_read(spi, HI3110_READ_STATF)))) {
>>> +            hi3110_hw_rx(spi);
>>> +        }
>>> +
>>> +        intf = hi3110_read(spi, HI3110_READ_INTF);
>>
>> I think HI3110_READ_ERR is only valid if HI3110_INT_BUSERR is set!
>> Therefore:
>>
>>                 if ((intf & HI3110_INT_BUSERR) {
>>
>> It saves reading one SPI register in the message processing path. Please
>> check if back-to-error-active still comes.
>>
>
> The top 3 bits of HI3110_READ_ERR (BUSOFF, TXERRP, RXERRP) are valid
> even if HI3110_INT_BUSERR is not set.

I'm confused! If you disable BUSERR interrupts, you do not get the 
status bits any longer, you said. But the manual says: "Bits 4:0 in the 
ERR register can be read to determine the source of the error.", which 
excludes the above bits... but obviously the controller does it that way.

Sorry for the noise,

Wolfgang.

Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Akshay Bhat]

Hi Wolfgang,

On 03/20/2017 12:46 PM, Wolfgang Grandegger wrote:
..snip..
>>
>> The top 3 bits of HI3110_READ_ERR (BUSOFF, TXERRP, RXERRP) are valid
>> even if HI3110_INT_BUSERR is not set.
> 
> I'm confused! If you disable BUSERR interrupts, you do not get the
> status bits any longer, you said. But the manual says: "Bits 4:0 in the
> ERR register can be read to determine the source of the error.", which
> excludes the above bits... but obviously the controller does it that way.
> 

I agree this feature could use better documentation.

Based on testing:

If BUSERRIE bit in INTE is clear,
On cable disconnect: No interrupts related to bus errors are generated.
So status change messages do not go out.

If BUSERRIE bit in INTE is set,
On cable disconnect: Interrupts are generated due to ACKERR. The
interrupt routine reads the BUSOFF/TXERRP/RXERRP bits of ERR register
and reports the state. If CAN_CTRLMODE_BERR_REPORTING is set, then
protocol errors are also reported by the interrupt.
On cable re-connect: Interrupts are generated due to TXCPLT. The
interrupt routine reads the BUSOFF/TXERRP/RXERRP bits of ERR register
and reports the state.

Let me know if this helps clear things up :)



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Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Akshay Bhat]

Hi Wolfgang,

On 03/20/2017 12:46 PM, Wolfgang Grandegger wrote:
..snip..
>>
>> The top 3 bits of HI3110_READ_ERR (BUSOFF, TXERRP, RXERRP) are valid
>> even if HI3110_INT_BUSERR is not set.
> 
> I'm confused! If you disable BUSERR interrupts, you do not get the
> status bits any longer, you said. But the manual says: "Bits 4:0 in the
> ERR register can be read to determine the source of the error.", which
> excludes the above bits... but obviously the controller does it that way.
> 

I agree this feature could use better documentation.

Based on testing:

If BUSERRIE bit in INTE is clear,
On cable disconnect: No interrupts related to bus errors are generated.
So status change messages do not go out.

If BUSERRIE bit in INTE is set,
On cable disconnect: Interrupts are generated due to ACKERR. The
interrupt routine reads the BUSOFF/TXERRP/RXERRP bits of ERR register
and reports the state. If CAN_CTRLMODE_BERR_REPORTING is set, then
protocol errors are also reported by the interrupt.
On cable re-connect: Interrupts are generated due to TXCPLT. The
interrupt routine reads the BUSOFF/TXERRP/RXERRP bits of ERR register
and reports the state.

Let me know if this helps clear things up :)

Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Akshay Bhat]

Hi Marc,

On 03/17/2017 05:10 PM, Akshay Bhat wrote:
> This patch adds support for the Holt HI-311x CAN controller. The HI311x
> CAN controller is capable of transmitting and receiving standard data
> frames, extended data frames and remote frames. The HI311x interfaces
> with the host over SPI.
> 
> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
> 
> Signed-off-by: Akshay Bhat <nodeax-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
> 

If there are no further review comments can this series be applied to
can-next or does it need to wait for the next kernel release cycle (4.13)?

Thanks,
Akshay
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Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Akshay Bhat]

Hi Marc,

On 03/17/2017 05:10 PM, Akshay Bhat wrote:
> This patch adds support for the Holt HI-311x CAN controller. The HI311x
> CAN controller is capable of transmitting and receiving standard data
> frames, extended data frames and remote frames. The HI311x interfaces
> with the host over SPI.
> 
> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
> 
> Signed-off-by: Akshay Bhat <nodeax@gmail.com>
> ---
> 

If there are no further review comments can this series be applied to
can-next or does it need to wait for the next kernel release cycle (4.13)?

Thanks,
Akshay

Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Marc Kleine-Budde]

[-- Attachment #1.1: Type: text/plain, Size: 2652 bytes --]

On 03/24/2017 06:20 PM, Akshay Bhat wrote:
> Hi Marc,
> 
> On 03/17/2017 05:10 PM, Akshay Bhat wrote:
>> This patch adds support for the Holt HI-311x CAN controller. The HI311x
>> CAN controller is capable of transmitting and receiving standard data
>> frames, extended data frames and remote frames. The HI311x interfaces
>> with the host over SPI.
>>
>> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
>>
>> Signed-off-by: Akshay Bhat <nodeax-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> ---
>>
> 
> If there are no further review comments can this series be applied to
> can-next or does it need to wait for the next kernel release cycle (4.13)?

The driver doesn't check if the workqueue allocation is successfull,
I've squashed this patch:

> diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
> index ff4bb40d855e..170e8e3971b2 100644
> --- a/drivers/net/can/spi/hi311x.c
> +++ b/drivers/net/can/spi/hi311x.c
> @@ -780,20 +780,24 @@ static int hi3110_open(struct net_device *net)
>  
>         priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
>                                    0);
> +       if (!priv->wq) {
> +               ret = -ENOMEM;
> +               goto out_free_irq;
> +       }
>         INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);
>         INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);
>  
>         ret = hi3110_hw_reset(spi);
>         if (ret)
> -               goto out_free_irq;
> +               goto out_free_wq;
>  
>         ret = hi3110_setup(net);
>         if (ret)
> -               goto out_free_irq;
> +               goto out_free_wq;
>  
>         ret = hi3110_set_normal_mode(spi);
>         if (ret)
> -               goto out_free_irq;
> +               goto out_free_wq;
>  
>         can_led_event(net, CAN_LED_EVENT_OPEN);
>         netif_wake_queue(net);
> @@ -801,11 +805,12 @@ static int hi3110_open(struct net_device *net)
>  
>         return 0;
>  
> -out_free_irq:
> + out_free_wq:
> +       destroy_workqueue(priv->wq);
> + out_free_irq:
>         free_irq(spi->irq, priv);
>         hi3110_hw_sleep(spi);
> -
> -out_close:
> + out_close:
>         hi3110_power_enable(priv->transceiver, 0);
>         close_candev(net);
>         mutex_unlock(&priv->hi3110_lock);

Marc

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Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Marc Kleine-Budde]

[-- Attachment #1.1: Type: text/plain, Size: 2622 bytes --]

On 03/24/2017 06:20 PM, Akshay Bhat wrote:
> Hi Marc,
> 
> On 03/17/2017 05:10 PM, Akshay Bhat wrote:
>> This patch adds support for the Holt HI-311x CAN controller. The HI311x
>> CAN controller is capable of transmitting and receiving standard data
>> frames, extended data frames and remote frames. The HI311x interfaces
>> with the host over SPI.
>>
>> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
>>
>> Signed-off-by: Akshay Bhat <nodeax@gmail.com>
>> ---
>>
> 
> If there are no further review comments can this series be applied to
> can-next or does it need to wait for the next kernel release cycle (4.13)?

The driver doesn't check if the workqueue allocation is successfull,
I've squashed this patch:

> diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
> index ff4bb40d855e..170e8e3971b2 100644
> --- a/drivers/net/can/spi/hi311x.c
> +++ b/drivers/net/can/spi/hi311x.c
> @@ -780,20 +780,24 @@ static int hi3110_open(struct net_device *net)
>  
>         priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
>                                    0);
> +       if (!priv->wq) {
> +               ret = -ENOMEM;
> +               goto out_free_irq;
> +       }
>         INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);
>         INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);
>  
>         ret = hi3110_hw_reset(spi);
>         if (ret)
> -               goto out_free_irq;
> +               goto out_free_wq;
>  
>         ret = hi3110_setup(net);
>         if (ret)
> -               goto out_free_irq;
> +               goto out_free_wq;
>  
>         ret = hi3110_set_normal_mode(spi);
>         if (ret)
> -               goto out_free_irq;
> +               goto out_free_wq;
>  
>         can_led_event(net, CAN_LED_EVENT_OPEN);
>         netif_wake_queue(net);
> @@ -801,11 +805,12 @@ static int hi3110_open(struct net_device *net)
>  
>         return 0;
>  
> -out_free_irq:
> + out_free_wq:
> +       destroy_workqueue(priv->wq);
> + out_free_irq:
>         free_irq(spi->irq, priv);
>         hi3110_hw_sleep(spi);
> -
> -out_close:
> + out_close:
>         hi3110_power_enable(priv->transceiver, 0);
>         close_candev(net);
>         mutex_unlock(&priv->hi3110_lock);

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Akshay Bhat]

On 04/04/2017 11:34 AM, Marc Kleine-Budde wrote:
> On 03/24/2017 06:20 PM, Akshay Bhat wrote:
>> Hi Marc,
>>
>> On 03/17/2017 05:10 PM, Akshay Bhat wrote:
>>> This patch adds support for the Holt HI-311x CAN controller. The HI311x
>>> CAN controller is capable of transmitting and receiving standard data
>>> frames, extended data frames and remote frames. The HI311x interfaces
>>> with the host over SPI.
>>>
>>> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
>>>
>>> Signed-off-by: Akshay Bhat <nodeax-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>>> ---
>>>
>>
>> If there are no further review comments can this series be applied to
>> can-next or does it need to wait for the next kernel release cycle (4.13)?
> 
> The driver doesn't check if the workqueue allocation is successfull,
> I've squashed this patch:
> 

Thanks Marc, appreciate it. The squashed patch looks good.
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Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver

[Akshay Bhat]

On 04/04/2017 11:34 AM, Marc Kleine-Budde wrote:
> On 03/24/2017 06:20 PM, Akshay Bhat wrote:
>> Hi Marc,
>>
>> On 03/17/2017 05:10 PM, Akshay Bhat wrote:
>>> This patch adds support for the Holt HI-311x CAN controller. The HI311x
>>> CAN controller is capable of transmitting and receiving standard data
>>> frames, extended data frames and remote frames. The HI311x interfaces
>>> with the host over SPI.
>>>
>>> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
>>>
>>> Signed-off-by: Akshay Bhat <nodeax@gmail.com>
>>> ---
>>>
>>
>> If there are no further review comments can this series be applied to
>> can-next or does it need to wait for the next kernel release cycle (4.13)?
> 
> The driver doesn't check if the workqueue allocation is successfull,
> I've squashed this patch:
> 

Thanks Marc, appreciate it. The squashed patch looks good.