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Date: Tue, 17 Jan 2017 14:11:33 -0500
From: Akshay Bhat <akshay.bhat@...esys.com>
To: Marc Kleine-Budde <mkl@...gutronix.de>, wg@...ndegger.com,
robh+dt@...nel.org
Cc: mark.rutland@....com, linux-can@...r.kernel.org,
netdev@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, Akshay Bhat <nodeax@...il.com>
Subject: Re: [PATCH 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver
Marc,
On 01/03/2017 10:31 AM, Marc Kleine-Budde wrote:
> On 11/14/2016 06:55 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.
>
> Don't use uint8_t and similar in the kernel, please use u8 instead.
>
Will fix in V2
>>
>> Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do
>>
>> Signed-off-by: Akshay Bhat <nodeax@...il.com>
>> ---
>> drivers/net/can/spi/Kconfig | 6 +
>> drivers/net/can/spi/Makefile | 1 +
>> drivers/net/can/spi/hi311x.c | 1071 ++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 1078 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..9eb1bb1 100644
>> --- a/drivers/net/can/spi/Kconfig
>> +++ b/drivers/net/can/spi/Kconfig
>> @@ -7,4 +7,10 @@ config CAN_MCP251X
>> ---help---
>> Driver for the Microchip MCP251x SPI CAN controllers.
>>
>> +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.
>> +
>> endmenu
>> diff --git a/drivers/net/can/spi/Makefile b/drivers/net/can/spi/Makefile
>> index 0e86040..eac7c3a 100644
>> --- a/drivers/net/can/spi/Makefile
>> +++ b/drivers/net/can/spi/Makefile
>> @@ -4,3 +4,4 @@
>>
>>
>> obj-$(CONFIG_CAN_MCP251X) += mcp251x.o
>> +obj-$(CONFIG_CAN_HI311X) += hi311x.o
>
> Please keep sorted alphabetically. Same for the Kconfig.
>
Will fix in V2
>> diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
>> new file mode 100644
>> index 0000000..1020166
>> --- /dev/null
>> +++ b/drivers/net/can/spi/hi311x.c
>> @@ -0,0 +1,1071 @@
>> +/* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
>> + *
>> + * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
>
> You might want to add the copyright of the mcp authors.
>
Will add in V2
>> + *
>> + * Copyright(C) Timesys Corporation 2016
>> + *
>> + * 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>
>> +
>
> Please use just a single space after each macro.
>
> VVVVVVVV
Will fix in V2.
>> +#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_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_STAT_RXFMTY BIT(1)
>> +
>> +#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
>> +
>
> Please add the already used HI3110_ namespace to these defines, too.
>
Will fix in V2.
>> +#define CAN_FRAME_MAX_DATA_LEN 8
>> +#define RX_BUF_LEN 15
>> +#define TX_STD_BUF_LEN 12
>> +#define TX_EXT_BUF_LEN 14
>> +#define CAN_FRAME_MAX_BITS 128
>> +
>> +#define 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,
> ^^^^^^^
> single space here, too
Will fix in V2
>> +};
>> +
>> +struct hi3110_priv {
>> + struct can_priv can;
> ^^^^
> here too
Will fix in V2
>> + 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;
>
> Please add the already used HI3110_ namespace to these defines, too.
>
Will fix in V2
>> +#define AFTER_SUSPEND_UP 1
>> +#define AFTER_SUSPEND_DOWN 2
>> +#define AFTER_SUSPEND_POWER 4
>> +#define 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, uint8_t 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, uint8_t 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];
>> + dev_dbg(&spi->dev, "hi3110_read: %02X, %02X\n", command, val);
>> +
>> + return val;
>> +}
>> +
>> +static void hi3110_write(struct spi_device *spi, u8 reg, uint8_t val)
>> +{
>> + struct hi3110_priv *priv = spi_get_drvdata(spi);
>> +
>> + priv->spi_tx_buf[0] = reg;
>> + priv->spi_tx_buf[1] = val;
>> + dev_dbg(&spi->dev, "hi3110_write: %02X, %02X\n", reg, 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[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) >> 18) & 0x07) << 5) |
>
> Why do you first shift down then up?
>
Simplified the logic in V2, shift down then up not needed
>> + 0x18 | /* Recessive SRR and IDE */
>
> Can you add a define for the 0x18?
>
Will add a define in V2
>> + (((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, TX_EXT_BUF_LEN -
>> + (CAN_FRAME_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, TX_STD_BUF_LEN -
>> + (CAN_FRAME_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, RX_BUF_LEN);
>> + memcpy(buf, priv->spi_rx_buf + 1, 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[RX_BUF_LEN - 1];
>> +
>> + skb = alloc_can_skb(priv->net, &frame);
>> + if (!skb) {
>> + dev_err(&spi->dev, "cannot allocate RX skb\n");
>> + 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);
>> + }
>> +
>> + if (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] & HI3110_FIFO_WOTIME_ID_RTR) {
>> + /* RTR is recessive (1), indicating remote request frame */
>> + frame->can_id |= CAN_RTR_FLAG;
>> + }
>> +
>> + /* Data length */
>> + frame->can_dlc = get_can_dlc(buf[HI3110_FIFO_WOTIME_DLC_OFF] & 0x0F);
>> + 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_warn(&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 = AFTER_SUSPEND_RESTART;
>> + queue_work(priv->wq, &priv->restart_work);
>> + break;
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int hi3110_set_normal_mode(struct spi_device *spi)
>> +{
>> + struct hi3110_priv *priv = spi_get_drvdata(spi);
>> + u8 reg;
>> +
>> + 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) {
>> + /* Put device into loopback mode */
>> + hi3110_write(spi, HI3110_WRITE_CTRL0,
>> + HI3110_CTRL0_LOOPBACK_MODE);
>> + } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
>> + /* Put device into listen-only mode */
>> + hi3110_write(spi, HI3110_WRITE_CTRL0,
>> + HI3110_CTRL0_MONITOR_MODE);
>> + } else {
>> + /* Put device into normal mode */
>> + hi3110_write(spi, HI3110_WRITE_CTRL0,
>> + HI3110_CTRL0_NORMAL_MODE);
>> +
>> + /* Wait for the device to enter normal mode */
>> + mdelay(HI3110_OST_DELAY_MS);
>> + reg = hi3110_read(spi, HI3110_READ_CTRL0);
>> + if ((reg & HI3110_CTRL0_MODE_MASK) != HI3110_CTRL0_NORMAL_MODE)
>> + 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, struct hi3110_priv *priv,
>> + struct spi_device *spi)
>
> onlt the first parameter is used.
>
Will remove the unused parameters in V2
>> +{
>> + 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 void hi3110_open_clean(struct net_device *net)
>> +{
>> + struct hi3110_priv *priv = netdev_priv(net);
>> + struct spi_device *spi = priv->spi;
>> +
>> + free_irq(spi->irq, priv);
>> + hi3110_hw_sleep(spi);
>> + hi3110_power_enable(priv->transceiver, 0);
>> + close_candev(net);
>> +}
>> +
>> +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_error_skb(struct net_device *net, int can_id,
>> + int data1, int data2)
>> +{
>> + struct sk_buff *skb;
>> + struct can_frame *frame;
>> +
>> + skb = alloc_can_err_skb(net, &frame);
>> + if (skb) {
>> + frame->can_id |= can_id;
>> + frame->data[1] = data1;
>> + frame->data[2] = data2;
>> + netif_rx_ni(skb);
>> + } else {
>> + netdev_err(net, "cannot allocate error skb\n");
>> + }
>> +}
>> +
>> +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;
>> +
>> + if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN)
>> + frame->can_dlc = CAN_FRAME_MAX_DATA_LEN;
>
> this has already been checked
>
Will remove the check in V2
>> + 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, priv, spi);
>> + if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
>> + hi3110_set_normal_mode(spi);
>> + } else if (priv->after_suspend & 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_clean(net);
>> + netif_wake_queue(net);
>> + hi3110_error_skb(net, CAN_ERR_RESTARTED, 0, 0);
>> + }
>> + 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;
>> + u8 eflag;
>> + int can_id = 0, data1 = 0, data2 = 0;
>> +
>> + while (!(HI3110_STAT_RXFMTY &
>> + hi3110_read(spi, HI3110_READ_STATF))) {
>> + hi3110_hw_rx(spi);
>> + };
>> +
>> + intf = hi3110_read(spi, HI3110_READ_INTF);
>> + eflag = hi3110_read(spi, HI3110_READ_ERR);
>
> does the hardware supports multiple reads with a single transfer? If so
> make use of it, for performance reasons.
>
Looking at the datasheet it does not seem possible, would be nice if it
was supported.
>> + /* Update can state */
>> + if (eflag & HI3110_ERR_BUSOFF) {
>> + new_state = CAN_STATE_BUS_OFF;
>> + can_id |= CAN_ERR_BUSOFF;
>> + } else if (eflag & HI3110_ERR_TXERRP) {
>> + new_state = CAN_STATE_ERROR_PASSIVE;
>> + can_id |= CAN_ERR_CRTL;
>> + data1 |= CAN_ERR_CRTL_TX_PASSIVE;
>> + } else if (eflag & HI3110_ERR_RXERRP) {
>> + new_state = CAN_STATE_ERROR_PASSIVE;
>> + can_id |= CAN_ERR_CRTL;
>> + data1 |= CAN_ERR_CRTL_RX_PASSIVE;
>> + } else {
>> + new_state = CAN_STATE_ERROR_ACTIVE;
>> + }
>> +
>> + /* Check for protocol errors */
>> + if (eflag & HI3110_ERR_PROTOCOL_MASK) {
>> + can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>> + priv->can.can_stats.bus_error++;
>> + priv->net->stats.rx_errors++;
>> + if (eflag & HI3110_ERR_BITERR)
>> + data2 |= CAN_ERR_PROT_BIT;
>> + else if (eflag & HI3110_ERR_FRMERR)
>> + data2 |= CAN_ERR_PROT_FORM;
>> + else if (eflag & HI3110_ERR_STUFERR)
>> + data2 |= CAN_ERR_PROT_STUFF;
>> + else
>> + data2 |= CAN_ERR_PROT_UNSPEC;
>> + }
>> +
>> + /* Update can state statistics */
>> + switch (priv->can.state) {
>> + case CAN_STATE_ERROR_ACTIVE:
>> + if (new_state >= CAN_STATE_ERROR_WARNING &&
>> + new_state <= CAN_STATE_BUS_OFF)
>> + priv->can.can_stats.error_warning++;
>> + /* fallthrough */
>> + case CAN_STATE_ERROR_WARNING:
>> + if (new_state >= CAN_STATE_ERROR_PASSIVE &&
>> + new_state <= CAN_STATE_BUS_OFF)
>> + priv->can.can_stats.error_passive++;
>> + break;
>> + default:
>> + break;
>> + }
>> + priv->can.state = new_state;
>> +
>> + if (intf & HI3110_INT_BUSERR) {
>> + /* Note: HI3110 Does report overflow errors */
>> + hi3110_error_skb(net, can_id, data1, data2);
>> + }
>> +
>> + if (priv->can.state == CAN_STATE_BUS_OFF) {
>> + if (priv->can.restart_ms == 0) {
>> + priv->force_quit = 1;
>> + priv->can.can_stats.bus_off++;
>> + can_bus_off(net);
>> + hi3110_hw_sleep(spi);
>> + break;
>> + }
>> + }
>> +
>> + 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) {
>> + dev_err(&spi->dev, "unable to set initial baudrate!\n");
>> + 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);
>
> add propoer goto targets at the and of this function, for easier error
> handling cleanup. This mean basically get rid of hi3110_open_clean(net).
>
Will fix in V2
>> + hi3110_power_enable(priv->transceiver, 0);
>> + close_candev(net);
>> + goto open_unlock;
>> + }
>> +
>> + 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) {
>> + hi3110_open_clean(net);
>> + goto open_unlock;
>> + }
>> + ret = hi3110_setup(net, priv, spi);
>> + if (ret) {
>> + hi3110_open_clean(net);
>> + goto open_unlock;
>> + }
>> + ret = hi3110_set_normal_mode(spi);
>> + if (ret) {
>> + hi3110_open_clean(net);
>> + goto open_unlock;
>> + }
>> + can_led_event(net, CAN_LED_EVENT_OPEN);
>> + netif_wake_queue(net);
>> +
>> +open_unlock:
>> + 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), 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.clock.freq = freq / 2;
>> + priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
>> + CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
>> + 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, RX_BUF_LEN,
>> + GFP_KERNEL);
>> + if (!priv->spi_tx_buf) {
>> + ret = -ENOMEM;
>> + goto error_probe;
>> + }
>> + priv->spi_rx_buf = devm_kzalloc(&spi->dev, 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 = AFTER_SUSPEND_UP;
>> + } else {
>> + priv->after_suspend = AFTER_SUSPEND_DOWN;
>> + }
>> +
>> + if (!IS_ERR_OR_NULL(priv->power)) {
>> + regulator_disable(priv->power);
>> + priv->after_suspend |= 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 & AFTER_SUSPEND_POWER)
>> + hi3110_power_enable(priv->power, 1);
>> +
>> + if (priv->after_suspend & 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@...esys.com>");
>> +MODULE_AUTHOR("Casey Fitzpatrick <casey.fitzpatrick@...esys.com>");
>> +MODULE_DESCRIPTION("Holt HI-3110 CAN driver");
>> +MODULE_LICENSE("GPL v2");
>>
>
> Marc
>
Thanks for all the feedback.
Akshay
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