--- /dev/null
+/* 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);
+ 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_wq;
+
+ ret = hi3110_setup(net);
+ if (ret)
+ goto out_free_wq;
+
+ ret = hi3110_set_normal_mode(spi);
+ if (ret)
+ goto out_free_wq;
+
+ can_led_event(net, CAN_LED_EVENT_OPEN);
+ netif_wake_queue(net);
+ mutex_unlock(&priv->hi3110_lock);
+
+ return 0;
+
+ out_free_wq:
+ destroy_workqueue(priv->wq);
+ 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");
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff