[PATCH 6/7] can: m_can: update to support CAN FD features
Dong Aisheng
b29396 at freescale.com
Wed Oct 29 03:45:26 PDT 2014
Bosch M_CAN is CAN FD capable device.
This patch implements the CAN FD features include up to 64 bytes
payload and bitrate switch function.
Signed-off-by: Dong Aisheng <b29396 at freescale.com>
---
drivers/net/can/m_can/m_can.c | 138 +++++++++++++++++++++++++++++++++---------
1 file changed, 110 insertions(+), 28 deletions(-)
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 6160b9c..219e0e3 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -105,14 +105,36 @@ enum m_can_mram_cfg {
MRAM_CFG_NUM,
};
+/* Fast Bit Timing & Prescaler Register (FBTP) */
+#define FBTR_FBRP_MASK 0x1f
+#define FBTR_FBRP_SHIFT 16
+#define FBTR_FTSEG1_SHIFT 8
+#define FBTR_FTSEG1_MASK (0xf << FBTR_FTSEG1_SHIFT)
+#define FBTR_FTSEG2_SHIFT 4
+#define FBTR_FTSEG2_MASK (0x7 << FBTR_FTSEG2_SHIFT)
+#define FBTR_FSJW_SHIFT 0
+#define FBTR_FSJW_MASK 0x3
+
/* Test Register (TEST) */
#define TEST_LBCK BIT(4)
/* CC Control Register(CCCR) */
-#define CCCR_TEST BIT(7)
-#define CCCR_MON BIT(5)
-#define CCCR_CCE BIT(1)
-#define CCCR_INIT BIT(0)
+#define CCCR_TEST BIT(7)
+#define CCCR_CMR_MASK 0x3
+#define CCCR_CMR_SHIFT 10
+#define CCCR_CMR_CANFD 0x1
+#define CCCR_CMR_CANFD_BRS 0x2
+#define CCCR_CMR_CAN 0x3
+#define CCCR_CME_MASK 0x3
+#define CCCR_CME_SHIFT 8
+#define CCCR_CME_CAN 0
+#define CCCR_CME_CANFD 0x1
+#define CCCR_CME_CANFD_BRS 0x2
+#define CCCR_TEST BIT(7)
+#define CCCR_MON BIT(5)
+#define CCCR_CCE BIT(1)
+#define CCCR_INIT BIT(0)
+#define CCCR_CANFD 0x10
/* Bit Timing & Prescaler Register (BTP) */
#define BTR_BRP_MASK 0x3ff
@@ -204,6 +226,7 @@ enum m_can_mram_cfg {
/* Rx Buffer / FIFO Element Size Configuration (RXESC) */
#define M_CAN_RXESC_8BYTES 0x0
+#define M_CAN_RXESC_64BYTES 0x777
/* Tx Buffer Configuration(TXBC) */
#define TXBC_NDTB_OFF 16
@@ -211,6 +234,7 @@ enum m_can_mram_cfg {
/* Tx Buffer Element Size Configuration(TXESC) */
#define TXESC_TBDS_8BYTES 0x0
+#define TXESC_TBDS_64BYTES 0x7
/* Tx Event FIFO Con.guration (TXEFC) */
#define TXEFC_EFS_OFF 16
@@ -219,11 +243,11 @@ enum m_can_mram_cfg {
/* Message RAM Configuration (in bytes) */
#define SIDF_ELEMENT_SIZE 4
#define XIDF_ELEMENT_SIZE 8
-#define RXF0_ELEMENT_SIZE 16
-#define RXF1_ELEMENT_SIZE 16
+#define RXF0_ELEMENT_SIZE 72
+#define RXF1_ELEMENT_SIZE 72
#define RXB_ELEMENT_SIZE 16
#define TXE_ELEMENT_SIZE 8
-#define TXB_ELEMENT_SIZE 16
+#define TXB_ELEMENT_SIZE 72
/* Message RAM Elements */
#define M_CAN_FIFO_ID 0x0
@@ -231,11 +255,17 @@ enum m_can_mram_cfg {
#define M_CAN_FIFO_DATA(n) (0x8 + ((n) << 2))
/* Rx Buffer Element */
+/* R0 */
#define RX_BUF_ESI BIT(31)
#define RX_BUF_XTD BIT(30)
#define RX_BUF_RTR BIT(29)
+/* R1 */
+#define RX_BUF_ANMF BIT(31)
+#define RX_BUF_EDL BIT(21)
+#define RX_BUF_BRS BIT(20)
/* Tx Buffer Element */
+/* R0 */
#define TX_BUF_XTD BIT(30)
#define TX_BUF_RTR BIT(29)
@@ -327,11 +357,12 @@ static inline void m_can_disable_all_interrupts(const struct m_can_priv *priv)
m_can_write(priv, M_CAN_ILE, 0x0);
}
-static void m_can_read_fifo(const struct net_device *dev, struct can_frame *cf,
+static void m_can_read_fifo(const struct net_device *dev, struct canfd_frame *cf,
u32 rxfs)
{
struct m_can_priv *priv = netdev_priv(dev);
u32 id, fgi;
+ int i;
/* calculate the fifo get index for where to read data */
fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_OFF;
@@ -341,15 +372,23 @@ static void m_can_read_fifo(const struct net_device *dev, struct can_frame *cf,
else
cf->can_id = (id >> 18) & CAN_SFF_MASK;
+ if (id & RX_BUF_ESI) {
+ cf->flags |= CANFD_ESI;
+ netdev_dbg(dev, "ESI Error\n");
+ }
+
if (id & RX_BUF_RTR) {
cf->can_id |= CAN_RTR_FLAG;
} else {
id = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DLC);
- cf->can_dlc = get_can_dlc((id >> 16) & 0x0F);
- *(u32 *)(cf->data + 0) = m_can_fifo_read(priv, fgi,
- M_CAN_FIFO_DATA(0));
- *(u32 *)(cf->data + 4) = m_can_fifo_read(priv, fgi,
- M_CAN_FIFO_DATA(1));
+ cf->len = can_dlc2len(get_canfd_dlc((id >> 16) & 0x0F));
+
+ if (id & RX_BUF_BRS)
+ cf->flags |= CANFD_BRS;
+
+ for (i = 0; i < cf->len; i += 4)
+ *(u32 *)(cf->data + i) =
+ m_can_fifo_read(priv, fgi, M_CAN_FIFO_DATA(i / 4));
}
/* acknowledge rx fifo 0 */
@@ -361,7 +400,7 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
struct m_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct sk_buff *skb;
- struct can_frame *frame;
+ struct canfd_frame *frame;
u32 pkts = 0;
u32 rxfs;
@@ -375,7 +414,7 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
if (rxfs & RXFS_RFL)
netdev_warn(dev, "Rx FIFO 0 Message Lost\n");
- skb = alloc_can_skb(dev, &frame);
+ skb = alloc_canfd_skb(dev, &frame);
if (!skb) {
stats->rx_dropped++;
return pkts;
@@ -384,7 +423,7 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
m_can_read_fifo(dev, frame, rxfs);
stats->rx_packets++;
- stats->rx_bytes += frame->can_dlc;
+ stats->rx_bytes += frame->len;
netif_receive_skb(skb);
@@ -744,10 +783,23 @@ static const struct can_bittiming_const m_can_bittiming_const = {
.brp_inc = 1,
};
+static const struct can_bittiming_const m_can_data_bittiming_const = {
+ .name = KBUILD_MODNAME,
+ .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
+ .tseg1_max = 16,
+ .tseg2_min = 1, /* Time segment 2 = phase_seg2 */
+ .tseg2_max = 8,
+ .sjw_max = 4,
+ .brp_min = 1,
+ .brp_max = 32,
+ .brp_inc = 1,
+};
+
static int m_can_set_bittiming(struct net_device *dev)
{
struct m_can_priv *priv = netdev_priv(dev);
const struct can_bittiming *bt = &priv->can.bittiming;
+ const struct can_bittiming *dbt = &priv->can.data_bittiming;
u16 brp, sjw, tseg1, tseg2;
u32 reg_btp;
@@ -758,7 +810,17 @@ static int m_can_set_bittiming(struct net_device *dev)
reg_btp = (brp << BTR_BRP_SHIFT) | (sjw << BTR_SJW_SHIFT) |
(tseg1 << BTR_TSEG1_SHIFT) | (tseg2 << BTR_TSEG2_SHIFT);
m_can_write(priv, M_CAN_BTP, reg_btp);
- netdev_dbg(dev, "setting BTP 0x%x\n", reg_btp);
+
+ if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
+ brp = dbt->brp - 1;
+ sjw = dbt->sjw - 1;
+ tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
+ tseg2 = dbt->phase_seg2 - 1;
+ reg_btp = (brp << FBTR_FBRP_SHIFT) | (sjw << FBTR_FSJW_SHIFT) |
+ (tseg1 << FBTR_FTSEG1_SHIFT) |
+ (tseg2 << FBTR_FTSEG2_SHIFT);
+ m_can_write(priv, M_CAN_FBTP, reg_btp);
+ }
return 0;
}
@@ -778,8 +840,8 @@ static void m_can_chip_config(struct net_device *dev)
m_can_config_endisable(priv, true);
- /* RX Buffer/FIFO Element Size 8 bytes data field */
- m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_8BYTES);
+ /* RX Buffer/FIFO Element Size 64 bytes data field */
+ m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_64BYTES);
/* Accept Non-matching Frames Into FIFO 0 */
m_can_write(priv, M_CAN_GFC, 0x0);
@@ -788,8 +850,8 @@ static void m_can_chip_config(struct net_device *dev)
m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_OFF) |
priv->mcfg[MRAM_TXB].off);
- /* only support 8 bytes firstly */
- m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_8BYTES);
+ /* support 64 bytes payload */
+ m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_64BYTES);
m_can_write(priv, M_CAN_TXEFC, (1 << TXEFC_EFS_OFF) |
priv->mcfg[MRAM_TXE].off);
@@ -804,7 +866,8 @@ static void m_can_chip_config(struct net_device *dev)
RXFC_FWM_1 | priv->mcfg[MRAM_RXF1].off);
cccr = m_can_read(priv, M_CAN_CCCR);
- cccr &= ~(CCCR_TEST | CCCR_MON);
+ cccr &= ~(CCCR_TEST | CCCR_MON | (CCCR_CMR_MASK << CCCR_CMR_SHIFT) |
+ (CCCR_CME_MASK << CCCR_CME_SHIFT));
test = m_can_read(priv, M_CAN_TEST);
test &= ~TEST_LBCK;
@@ -816,6 +879,9 @@ static void m_can_chip_config(struct net_device *dev)
test |= TEST_LBCK;
}
+ if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+ cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;
+
m_can_write(priv, M_CAN_CCCR, cccr);
m_can_write(priv, M_CAN_TEST, test);
@@ -880,11 +946,13 @@ static struct net_device *alloc_m_can_dev(void)
priv->dev = dev;
priv->can.bittiming_const = &m_can_bittiming_const;
+ priv->can.data_bittiming_const = &m_can_data_bittiming_const;
priv->can.do_set_mode = m_can_set_mode;
priv->can.do_get_berr_counter = m_can_get_berr_counter;
priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
CAN_CTRLMODE_LISTENONLY |
- CAN_CTRLMODE_BERR_REPORTING;
+ CAN_CTRLMODE_BERR_REPORTING |
+ CAN_CTRLMODE_FD;
return dev;
}
@@ -967,8 +1035,9 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct m_can_priv *priv = netdev_priv(dev);
- struct can_frame *cf = (struct can_frame *)skb->data;
- u32 id;
+ struct canfd_frame *cf = (struct canfd_frame *)skb->data;
+ u32 id, cccr;
+ int i;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
@@ -987,11 +1056,24 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
/* message ram configuration */
m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id);
- m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, cf->can_dlc << 16);
- m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(0), *(u32 *)(cf->data + 0));
- m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(1), *(u32 *)(cf->data + 4));
+ m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, can_len2dlc(cf->len) << 16);
+
+ for (i = 0; i < cf->len; i += 4)
+ m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(i / 4),
+ *(u32 *)(cf->data + i));
+
can_put_echo_skb(skb, dev, 0);
+ if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
+ cccr = m_can_read(priv, M_CAN_CCCR);
+ cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
+ if (cf->flags & CANFD_BRS
+ cccr |= CCCR_CMR_CANFD_BRS << CCCR_CMR_SHIFT;
+ else
+ cccr |= CCCR_CMR_CANFD << CCCR_CMR_SHIFT;
+ m_can_write(priv, M_CAN_CCCR, cccr);
+ }
+
/* enable first TX buffer to start transfer */
m_can_write(priv, M_CAN_TXBTIE, 0x1);
m_can_write(priv, M_CAN_TXBAR, 0x1);
--
1.9.1
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