Project

General

Profile

新建 #111 » rockchip_can(6).c

余 顺, 09/16/2022 09:00 AM

 
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2020 Rockchip Electronics Co. Ltd.
* Rockchip CAN driver
*/

#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/led.h>
#include <linux/clk.h>
#include <linux/netdevice.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of_device.h>
#include <linux/reset.h>
#include <linux/pm_runtime.h>

#define DRV_NAME "rockchip_can"

#define CAN_MODE 0x00
#define RESET_MODE 0
#define WORK_MODE BIT(0)
#define SELF_TEST_EN BIT(2)
#define MODE_AUTO_RETX BIT(10)

#define CAN_CMD 0x04
#define TX_REQ BIT(0)

#define CAN_STATE 0x08
#define RX_BUF_FULL BIT(0)
#define TX_BUF_FULL BIT(1)
#define RX_PERIOD BIT(2)
#define TX_PERIOD BIT(3)
#define ERR_WARN BIT(4)
#define BUS_OFF BIT(5)

#define CAN_INT 0x0C

#define CAN_INT_MASK 0x10
#define RX_FINISH BIT(0)
#define TX_FINISH BIT(1)
#define ERR_WARN_INT BIT(2)
#define RX_BUF_OV BIT(3)
#define PASSIVE_ERR BIT(4)
#define TX_LOSTARB BIT(5)
#define BUS_ERR_INT BIT(6)

/* Bit Timing Register */
#define CAN_BTT 0x18
#define MODE_3_SAMPLES BIT(16)
#define BT_SJW_SHIFT 14
#define BT_SJW_MASK GENMASK(15, 14)
#define BT_BRP_SHIFT 8
#define BT_BRP_MASK GENMASK(13, 8)
#define BT_TSEG2_SHIFT 4
#define BT_TSEG2_MASK GENMASK(6, 4)
#define BT_TSEG1_SHIFT 0
#define BT_TSEG1_MASK GENMASK(3, 0)

#define CAN_LOSTARB_CODE 0x28

#define CAN_ERR_CODE 0x2c
#define ERR_TYPE_MASK GENMASK(24, 22)
#define ERR_TYPE_SHIFT 22
#define BIT_ERR 0
#define STUFF_ERR 1
#define FORM_ERR 2
#define ACK_ERR 3
#define CRC_ERR 4
#define ERR_DIR_RX BIT(21)
#define ERR_LOC_MASK GENMASK(13, 0)

#define CAN_RX_ERR_CNT 0x34

#define CAN_TX_ERR_CNT 0x38

#define CAN_ID 0x3c

#define CAN_ID_MASK 0x40

#define CAN_TX_FRM_INFO 0x50
#define CAN_EFF BIT(7)
#define CAN_RTR BIT(6)
#define CAN_DLC_MASK GENMASK(3, 0)
#define CAN_DLC(x) ((x) & GENMASK(3, 0))

#define CAN_TX_ID 0x54
#define CAN_TX_ID_MASK 0x1fffffff

#define CAN_TX_DATA1 0x58

#define CAN_TX_DATA2 0x5c

#define CAN_RX_FRM_INFO 0x60

#define CAN_RX_ID 0x64

#define CAN_RX_DATA1 0x68

#define CAN_RX_DATA2 0x6c

#define CAN_RX_FILTER_MASK 0x1fffffff

#define CAN_VERSION 0x70

struct rockchip_can {
struct can_priv can;
void __iomem *base;
struct device *dev;
struct clk_bulk_data *clks;
int num_clks;
struct reset_control *reset;
};

static const struct can_bittiming_const rockchip_can_bittiming_const = {
.name = DRV_NAME,
.tseg1_min = 1,
.tseg1_max = 16,
.tseg2_min = 1,
.tseg2_max = 8,
.sjw_max = 4,
.brp_min = 1,
.brp_max = 128,
.brp_inc = 2,
};

static void rockchip_can_write_cmdreg(struct rockchip_can *rcan, u8 val)
{
writel(val, rcan->base + CAN_CMD);
}

static int set_reset_mode(struct net_device *ndev)
{
struct rockchip_can *rcan = netdev_priv(ndev);

reset_control_assert(rcan->reset);
udelay(2);
reset_control_deassert(rcan->reset);

writel(0, rcan->base + CAN_MODE);

return 0;
}

static int set_normal_mode(struct net_device *ndev)
{
struct rockchip_can *rcan = netdev_priv(ndev);
u32 val;

val = readl(rcan->base + CAN_MODE);
val |= WORK_MODE | MODE_AUTO_RETX;
writel(val, rcan->base + CAN_MODE);

return 0;
}

/* bittiming is called in reset_mode only */
static int rockchip_can_set_bittiming(struct net_device *ndev)
{
struct rockchip_can *rcan = netdev_priv(ndev);
struct can_bittiming *bt = &rcan->can.bittiming;
u32 cfg;

cfg = ((bt->sjw - 1) << BT_SJW_SHIFT) |
(((bt->brp >> 1) - 1) << BT_BRP_SHIFT) |
((bt->phase_seg2 - 1) << BT_TSEG2_SHIFT) |
((bt->prop_seg + bt->phase_seg1 - 1));
if (rcan->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
cfg |= MODE_3_SAMPLES;

writel(cfg, rcan->base + CAN_BTT);

netdev_dbg(ndev, "setting BITTIMING=0x%08x brp: %d bitrate:%d\n",
cfg, bt->brp, bt->bitrate);

return 0;
}

static int rockchip_can_get_berr_counter(const struct net_device *ndev,
struct can_berr_counter *bec)
{
struct rockchip_can *rcan = netdev_priv(ndev);
int err;

err = pm_runtime_get_sync(rcan->dev);
if (err < 0) {
netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
__func__, err);
return err;
}

bec->rxerr = readl(rcan->base + CAN_RX_ERR_CNT);
bec->txerr = readl(rcan->base + CAN_TX_ERR_CNT);

pm_runtime_put(rcan->dev);

netdev_dbg(ndev, "%s\n", __func__);
return 0;
}

static int rockchip_can_start(struct net_device *ndev)
{
struct rockchip_can *rcan = netdev_priv(ndev);

/* we need to enter the reset mode */
set_reset_mode(ndev);

writel(0, rcan->base + CAN_INT_MASK);

/* RECEIVING FILTER, accept all */
writel(0, rcan->base + CAN_ID);
writel(CAN_RX_FILTER_MASK, rcan->base + CAN_ID_MASK);

rockchip_can_set_bittiming(ndev);

set_normal_mode(ndev);

rcan->can.state = CAN_STATE_ERROR_ACTIVE;

netdev_dbg(ndev, "%s\n", __func__);
return 0;
}

static int rockchip_can_stop(struct net_device *ndev)
{
struct rockchip_can *rcan = netdev_priv(ndev);
u32 val;

rcan->can.state = CAN_STATE_STOPPED;
/* we need to enter reset mode */
set_reset_mode(ndev);

/* disable all interrupts */
val = RX_FINISH | TX_FINISH | ERR_WARN_INT |
RX_BUF_OV | PASSIVE_ERR | TX_LOSTARB |
BUS_ERR_INT;

writel(val, rcan->base + CAN_INT_MASK);
netdev_dbg(ndev, "%s\n", __func__);
return 0;
}

static int rockchip_can_set_mode(struct net_device *ndev, enum can_mode mode)
{
int err;

netdev_dbg(ndev, "can set mode: 0x%x\n", mode);

switch (mode) {
case CAN_MODE_START:
err = rockchip_can_start(ndev);
if (err) {
netdev_err(ndev, "starting CAN controller failed!\n");
return err;
}
if (netif_queue_stopped(ndev))
netif_wake_queue(ndev);
break;

default:
return -EOPNOTSUPP;
}

return 0;
}

/* transmit a CAN message
* message layout in the sk_buff should be like this:
* xx xx xx xx ff ll 00 11 22 33 44 55 66 77
* [ can_id ] [flags] [len] [can data (up to 8 bytes]
*/
static int rockchip_can_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
struct rockchip_can *rcan = netdev_priv(ndev);
struct can_frame *cf = (struct can_frame *)skb->data;
canid_t id;
u8 dlc;
u32 fi;
u32 data1 = 0, data2 = 0;

if (can_dropped_invalid_skb(ndev, skb))
return NETDEV_TX_OK;

netif_stop_queue(ndev);

id = cf->can_id;
dlc = cf->can_dlc;
fi = dlc;

if (id & CAN_RTR_FLAG) {
fi |= CAN_RTR;
fi &= ~CAN_DLC_MASK;
}

if (id & CAN_EFF_FLAG)
fi |= CAN_EFF;

rockchip_can_write_cmdreg(rcan, 0);

writel(id & CAN_TX_ID_MASK, rcan->base + CAN_TX_ID);
if (!(id & CAN_RTR_FLAG)) {
data1 = le32_to_cpup((__le32 *)&cf->data[0]);
data2 = le32_to_cpup((__le32 *)&cf->data[4]);
writel(data1, rcan->base + CAN_TX_DATA1);
writel(data2, rcan->base + CAN_TX_DATA2);
}

writel(fi, rcan->base + CAN_TX_FRM_INFO);
can_put_echo_skb(skb, ndev, 0);

rockchip_can_write_cmdreg(rcan, TX_REQ);
netdev_dbg(ndev, "TX: can_id:0x%08x dlc: %d mode: 0x%08x data: 0x%08x 0x%08x\n",
cf->can_id, cf->can_dlc, rcan->can.ctrlmode, data1, data2);

return NETDEV_TX_OK;
}

static void rockchip_can_rx(struct net_device *ndev)
{
struct rockchip_can *rcan = netdev_priv(ndev);
struct net_device_stats *stats = &ndev->stats;
struct can_frame *cf;
struct sk_buff *skb;
canid_t id;
u8 fi;
u32 data1 = 0, data2 = 0;

/* create zero'ed CAN frame buffer */
skb = alloc_can_skb(ndev, &cf);
if (!skb)
return;

fi = readl(rcan->base + CAN_RX_FRM_INFO);
cf->can_dlc = get_can_dlc(fi & CAN_DLC_MASK);
id = readl(rcan->base + CAN_RX_ID);
if (fi & CAN_EFF)
id |= CAN_EFF_FLAG;

/* remote frame ? */
if (fi & CAN_RTR) {
id |= CAN_RTR_FLAG;
} else {
data1 = readl(rcan->base + CAN_RX_DATA1);
data2 = readl(rcan->base + CAN_RX_DATA2);
}

cf->can_id = id;
*(__le32 *)(cf->data + 0) = cpu_to_le32(data1);
*(__le32 *)(cf->data + 4) = cpu_to_le32(data2);

stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
netif_rx(skb);

can_led_event(ndev, CAN_LED_EVENT_RX);

netdev_dbg(ndev, "%s can_id:0x%08x fi: 0x%08x dlc: %d data: 0x%08x 0x%08x\n",
__func__, cf->can_id, fi, cf->can_dlc,
data1, data2);
}

static void rockchip_can_clean_rx_info(struct rockchip_can *rcan)
{
readl(rcan->base + CAN_RX_FRM_INFO);
readl(rcan->base + CAN_RX_ID);
readl(rcan->base + CAN_RX_DATA1);
readl(rcan->base + CAN_RX_DATA2);
}

static int rockchip_can_err(struct net_device *ndev, u8 isr)
{
struct rockchip_can *rcan = netdev_priv(ndev);
struct net_device_stats *stats = &ndev->stats;
struct can_frame *cf;
struct sk_buff *skb;
unsigned int rxerr, txerr;
u32 sta_reg;

skb = alloc_can_err_skb(ndev, &cf);

rxerr = readl(rcan->base + CAN_RX_ERR_CNT);
txerr = readl(rcan->base + CAN_TX_ERR_CNT);
sta_reg = readl(rcan->base + CAN_STATE);
// printk("rxerr = %x txerr=%x sta_reg= %x isr= %x \n", rxerr, txerr, sta_reg, isr);

if (sta_reg & BUS_OFF) {
rcan->can.state = CAN_STATE_BUS_OFF;
//rcan->can.can_stats.bus_off++;
//cf->can_id |= CAN_ERR_BUSOFF;
} else if (sta_reg & ERR_WARN) {
rcan->can.can_stats.error_warning++;
rcan->can.state = CAN_STATE_ERROR_WARNING;
/* error warning state */
if (likely(skb)) {
cf->can_id |= CAN_ERR_CRTL;
cf->data[1] = (txerr > rxerr) ?
CAN_ERR_CRTL_TX_WARNING :
CAN_ERR_CRTL_RX_WARNING;
cf->data[6] = txerr;
cf->data[7] = rxerr;
}
} else if (isr & PASSIVE_ERR) {
rcan->can.can_stats.error_passive++;
rcan->can.state = CAN_STATE_ERROR_PASSIVE;
/* error passive state */
cf->can_id |= CAN_ERR_CRTL;
cf->data[1] = (txerr > rxerr) ?
CAN_ERR_CRTL_TX_WARNING :
CAN_ERR_CRTL_RX_WARNING;
cf->data[6] = txerr;
cf->data[7] = rxerr;
}

if ((rcan->can.state != CAN_STATE_ERROR_WARNING)) {

netif_stop_queue(ndev);
rockchip_can_stop(ndev);
can_free_echo_skb(ndev, 0);
rockchip_can_start(ndev);
netif_start_queue(ndev);
//can_bus_off(ndev);
}

stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
netif_receive_skb(skb);

return 0;
}

static irqreturn_t rockchip_can_interrupt(int irq, void *dev_id)
{
struct net_device *ndev = (struct net_device *)dev_id;
struct rockchip_can *rcan = netdev_priv(ndev);
struct net_device_stats *stats = &ndev->stats;
u8 err_int = ERR_WARN_INT | RX_BUF_OV | PASSIVE_ERR |
TX_LOSTARB | BUS_ERR_INT;
u8 isr;

isr = readl(rcan->base + CAN_INT);
if (isr & TX_FINISH) {
/* transmission complete interrupt */
stats->tx_bytes += readl(rcan->base + CAN_TX_FRM_INFO) &
CAN_DLC_MASK;
stats->tx_packets++;
rockchip_can_write_cmdreg(rcan, 0);
can_get_echo_skb(ndev, 0);
netif_wake_queue(ndev);
can_led_event(ndev, CAN_LED_EVENT_TX);
}

if (isr & RX_FINISH)
rockchip_can_rx(ndev);

if (isr & err_int) {
rockchip_can_clean_rx_info(rcan);
if (rockchip_can_err(ndev, isr))
netdev_err(ndev, "can't allocate buffer - clearing pending interrupts\n");
}

writel(isr, rcan->base + CAN_INT);
rockchip_can_clean_rx_info(rcan);
netdev_dbg(ndev, "isr: 0x%x\n", isr);
return IRQ_HANDLED;
}

static int rockchip_can_open(struct net_device *ndev)
{
struct rockchip_can *rcan = netdev_priv(ndev);
int err;

/* common open */
err = open_candev(ndev);
if (err)
return err;

err = pm_runtime_get_sync(rcan->dev);
if (err < 0) {
netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
__func__, err);
goto exit;
}

err = rockchip_can_start(ndev);
if (err) {
netdev_err(ndev, "could not start CAN peripheral\n");
goto exit_can_start;
}

can_led_event(ndev, CAN_LED_EVENT_OPEN);
netif_start_queue(ndev);

netdev_dbg(ndev, "%s\n", __func__);
return 0;

exit_can_start:
pm_runtime_put(rcan->dev);
exit:
close_candev(ndev);
return err;
}

static int rockchip_can_close(struct net_device *ndev)
{
struct rockchip_can *rcan = netdev_priv(ndev);

netif_stop_queue(ndev);
rockchip_can_stop(ndev);
close_candev(ndev);
can_led_event(ndev, CAN_LED_EVENT_STOP);
pm_runtime_put(rcan->dev);

netdev_dbg(ndev, "%s\n", __func__);
return 0;
}

static const struct net_device_ops rockchip_can_netdev_ops = {
.ndo_open = rockchip_can_open,
.ndo_stop = rockchip_can_close,
.ndo_start_xmit = rockchip_can_start_xmit,
};

/**
* rockchip_can_suspend - Suspend method for the driver
* @dev: Address of the device structure
*
* Put the driver into low power mode.
* Return: 0 on success and failure value on error
*/
static int __maybe_unused rockchip_can_suspend(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);

if (netif_running(ndev)) {
netif_stop_queue(ndev);
netif_device_detach(ndev);
rockchip_can_stop(ndev);
}

return pm_runtime_force_suspend(dev);
}

/**
* rockchip_can_resume - Resume from suspend
* @dev: Address of the device structure
*
* Resume operation after suspend.
* Return: 0 on success and failure value on error
*/
static int __maybe_unused rockchip_can_resume(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);
int ret;

ret = pm_runtime_force_resume(dev);
if (ret) {
dev_err(dev, "pm_runtime_force_resume failed on resume\n");
return ret;
}

if (netif_running(ndev)) {
ret = rockchip_can_start(ndev);
if (ret) {
dev_err(dev, "rockchip_can_chip_start failed on resume\n");
return ret;
}

netif_device_attach(ndev);
netif_start_queue(ndev);
}

return 0;
}

/**
* rockchip_can_runtime_suspend - Runtime suspend method for the driver
* @dev: Address of the device structure
*
* Put the driver into low power mode.
* Return: 0 always
*/
static int __maybe_unused rockchip_can_runtime_suspend(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);
struct rockchip_can *rcan = netdev_priv(ndev);

clk_bulk_disable_unprepare(rcan->num_clks, rcan->clks);

return 0;
}

/**
* rockchip_can_runtime_resume - Runtime resume from suspend
* @dev: Address of the device structure
*
* Resume operation after suspend.
* Return: 0 on success and failure value on error
*/
static int __maybe_unused rockchip_can_runtime_resume(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);
struct rockchip_can *rcan = netdev_priv(ndev);
int ret;

ret = clk_bulk_prepare_enable(rcan->num_clks, rcan->clks);
if (ret) {
dev_err(dev, "Cannot enable clock.\n");
return ret;
}

return 0;
}

static const struct dev_pm_ops rockchip_can_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(rockchip_can_suspend, rockchip_can_resume)
SET_RUNTIME_PM_OPS(rockchip_can_runtime_suspend,
rockchip_can_runtime_resume, NULL)
};

static const struct of_device_id rockchip_can_of_match[] = {
{.compatible = "rockchip,can-1.0"},
{},
};
MODULE_DEVICE_TABLE(of, rockchip_can_of_match);

static int rockchip_can_probe(struct platform_device *pdev)
{
struct net_device *ndev;
struct rockchip_can *rcan;
struct resource *res;
void __iomem *addr;
int err, irq;

irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "could not get a valid irq\n");
return -ENODEV;
}

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
addr = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(addr))
return -EBUSY;

ndev = alloc_candev(sizeof(struct rockchip_can), 1);
if (!ndev) {
dev_err(&pdev->dev, "could not allocate memory for CAN device\n");
return -ENOMEM;
}

ndev->netdev_ops = &rockchip_can_netdev_ops;
ndev->irq = irq;
ndev->flags |= IFF_ECHO;

rcan = netdev_priv(ndev);

/* register interrupt handler */
err = devm_request_irq(&pdev->dev, ndev->irq, rockchip_can_interrupt,
0, ndev->name, ndev);
if (err) {
dev_err(&pdev->dev, "request_irq err: %d\n", err);
return err;
}

rcan->reset = devm_reset_control_array_get(&pdev->dev, false, false);
if (IS_ERR(rcan->reset)) {
if (PTR_ERR(rcan->reset) != -EPROBE_DEFER)
dev_err(&pdev->dev, "failed to get rcan reset lines\n");
return PTR_ERR(rcan->reset);
}

rcan->num_clks = devm_clk_bulk_get_all(&pdev->dev, &rcan->clks);
if (rcan->num_clks < 1) {
dev_err(&pdev->dev, "bus clock not found\n");
return -ENODEV;
}

rcan->dev = &pdev->dev;
rcan->can.clock.freq = clk_get_rate(rcan->clks[0].clk);
rcan->can.bittiming_const = &rockchip_can_bittiming_const;
rcan->can.do_set_mode = rockchip_can_set_mode;
rcan->can.do_get_berr_counter = rockchip_can_get_berr_counter;
rcan->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING |
CAN_CTRLMODE_LISTENONLY |
CAN_CTRLMODE_LOOPBACK |
CAN_CTRLMODE_3_SAMPLES;
rcan->base = addr;
platform_set_drvdata(pdev, ndev);
SET_NETDEV_DEV(ndev, &pdev->dev);

pm_runtime_enable(&pdev->dev);
err = pm_runtime_get_sync(&pdev->dev);
if (err < 0) {
dev_err(&pdev->dev, "%s: pm_runtime_get failed(%d)\n",
__func__, err);
goto err_pmdisable;
}

err = register_candev(ndev);
if (err) {
dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
DRV_NAME, err);
goto err_disableclks;
}

devm_can_led_init(ndev);

pm_runtime_put(&pdev->dev);

return 0;

err_disableclks:
pm_runtime_put(&pdev->dev);
err_pmdisable:
pm_runtime_disable(&pdev->dev);
free_candev(ndev);

return err;
}

static int rockchip_can_remove(struct platform_device *pdev)
{
struct net_device *ndev = platform_get_drvdata(pdev);

unregister_netdev(ndev);
pm_runtime_disable(&pdev->dev);
free_candev(ndev);

return 0;
}

static struct platform_driver rockchip_can_driver = {
.driver = {
.name = DRV_NAME,
.pm = &rockchip_can_dev_pm_ops,
.of_match_table = rockchip_can_of_match,
},
.probe = rockchip_can_probe,
.remove = rockchip_can_remove,
};
module_platform_driver(rockchip_can_driver);

MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com>");
MODULE_DESCRIPTION("Rockchip CAN Drivers");
(7-7/7)