On 07/04/2014 01:53 PM, Dong Aisheng wrote: > The patch adds the basic CAN TX/RX function support for Bosch M_CAN controller. > For TX, only one dedicated tx buffer is used for sending data. > For RX, RXFIFO 0 is used for receiving data to avoid overflow. > Rx FIFO 1 and Rx Buffers are not used currently, as well as Tx Event FIFO. > > Due to the message ram can be shared by multi m_can instances > and the fifo element is configurable which is SoC dependant, > the design is to parse the message ram related configuration data from device > tree rather than hardcode define it in driver which can make the message > ram sharing fully transparent to M_CAN controller driver, > then we can gain better driver maintainability and future features upgrade. > > M_CAN also supports CANFD protocol features like data payload up to 64 bytes > and bitrate switch at runtime, however, this patch still does not add the > support for these features. > > Signed-off-by: Dong Aisheng <b29396@xxxxxxxxxxxxx> Looks quite god, comments inline. Marc > --- > Changes since v1: > Addressed all comments from Mark Rutland, Hartkopp and Marc Kleine-Budde > - merge three patches into one > - create directory drivers/net/can/m_can > - improve binding doc > - make sure using valid pointer before netif_receive_skb(skb) > - remove debug info a bit > - let the stats are updated even if alloc_can_err_skb() fails > - other small fixes > > Test result: > Passed over night can-utils/canfdtest stress test on iMX6SX SDB board. > > --- > .../devicetree/bindings/net/can/m_can.txt | 65 ++ Please put the DT binding doc into a separate patch. > drivers/net/can/Kconfig | 2 + > drivers/net/can/Makefile | 1 + > drivers/net/can/m_can/Kconfig | 4 + > drivers/net/can/m_can/Makefile | 7 + > drivers/net/can/m_can/m_can.c | 1136 ++++++++++++++++++++ > 6 files changed, 1215 insertions(+), 0 deletions(-) > create mode 100644 Documentation/devicetree/bindings/net/can/m_can.txt > create mode 100644 drivers/net/can/m_can/Kconfig > create mode 100644 drivers/net/can/m_can/Makefile > create mode 100644 drivers/net/can/m_can/m_can.c > > diff --git a/Documentation/devicetree/bindings/net/can/m_can.txt b/Documentation/devicetree/bindings/net/can/m_can.txt > new file mode 100644 > index 0000000..3422790 > --- /dev/null > +++ b/Documentation/devicetree/bindings/net/can/m_can.txt > @@ -0,0 +1,65 @@ > +Bosch MCAN controller Device Tree Bindings > +------------------------------------------------- > + > +Required properties: > +- compatible : Should be "bosch,m_can" for M_CAN controllers > +- reg : physical base address and size of the M_CAN > + registers map and Message RAM > +- reg-names : Should be "m_can" and "message_ram" > +- interrupts : Should be the interrupt number of M_CAN interrupt > + line 0 and line 1, could be same if sharing > + the same interrupt. > +- interrupt-names : Should contain "int0" and "int1" You make only use of one interupt in the driver. > +- clocks : Clocks used by controller, should be host clock > + and CAN clock. > +- clock-names : Should contain "hclk" and "cclk" > +- pinctrl-<n> : Pinctrl states as described in bindings/pinctrl/pinctrl-bindings.txt > +- pinctrl-names : Names corresponding to the numbered pinctrl states is pinctrl really required? > +- mram-cfg : Message RAM configuration data. > + Multiple M_CAN instances can share the same Message RAM and each element(e.g > + Rx FIFO or Tx Buffer and etc) number in Message RAM is also configurable, > + so this property is telling driver how the shared or private Message RAM > + are used by this M_CAN controller. > + > + The format should be as follows: > + <offset sidf_elems xidf_elems rxf0_elems rxf1_elems rxb_elems > + txe_elems txb_elems> > + The 'offset' is an address offset of the Message RAM where the following > + elements start from. This is usually set to 0x0 if you're using a private > + Message RAM. The remain cells are used to specify how many elements are used > + for each FIFO/Buffer. > + > +M_CAN includes the following elements according to user manual: > +11-bit Filter 0-128 elements / 0-128 words > +29-bit Filter 0-64 elements / 0-128 words > +Rx FIFO 0 0-64 elements / 0-1152 words > +Rx FIFO 1 0-64 elements / 0-1152 words > +Rx Buffers 0-64 elements / 0-1152 words > +Tx Event FIFO 0-32 elements / 0-64 words > +Tx Buffers 0-32 elements / 0-576 words > + > +Please refer to 2.4.1 Message RAM Configuration in Bosch M_CAN user manual > +for details. > + > +Example: > +SoC dtsi: > +m_can1: can@020e8000 { > + compatible = "bosch,m_can"; > + reg = <0x020e8000 0x4000>, <0x02298000 0x4000>; > + reg-names = "m_can", "message_ram"; > + interrupts = <0 114 0x04>, > + <0 114 0x04>; > + interrupt-names = "int0", "int1"; > + clocks = <&clks IMX6SX_CLK_CANFD>, > + <&clks IMX6SX_CLK_CANFD>; > + clock-names = "hclk", "cclk"; > + mram-cfg = <0x0 0 0 32 32 32 0 1>; Why are you allocating rc fifo1 and rx buffers if you don't use them. > + status = "disabled"; > +}; > + > +Board dtsi: > +&m_can1 { > + pinctrl-names = "default"; > + pinctrl-0 = <&pinctrl_m_can1>; > + status = "enabled"; > +}; > diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig > index 4168822..e78d6b3 100644 > --- a/drivers/net/can/Kconfig > +++ b/drivers/net/can/Kconfig > @@ -143,6 +143,8 @@ source "drivers/net/can/sja1000/Kconfig" > > source "drivers/net/can/c_can/Kconfig" > > +source "drivers/net/can/m_can/Kconfig" > + > source "drivers/net/can/cc770/Kconfig" > > source "drivers/net/can/spi/Kconfig" > diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile > index 1697f22..1b4b6eb 100644 > --- a/drivers/net/can/Makefile > +++ b/drivers/net/can/Makefile > @@ -17,6 +17,7 @@ obj-y += softing/ > obj-$(CONFIG_CAN_SJA1000) += sja1000/ > obj-$(CONFIG_CAN_MSCAN) += mscan/ > obj-$(CONFIG_CAN_C_CAN) += c_can/ > +obj-$(CONFIG_CAN_M_CAN) += m_can/ > obj-$(CONFIG_CAN_CC770) += cc770/ > obj-$(CONFIG_CAN_AT91) += at91_can.o > obj-$(CONFIG_CAN_TI_HECC) += ti_hecc.o > diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig > new file mode 100644 > index 0000000..fca5482 > --- /dev/null > +++ b/drivers/net/can/m_can/Kconfig > @@ -0,0 +1,4 @@ > +config CAN_M_CAN > + tristate "Bosch M_CAN devices" > + ---help--- > + Say Y here if you want to support for Bosch M_CAN controller. > diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile > new file mode 100644 > index 0000000..a6aae67 > --- /dev/null > +++ b/drivers/net/can/m_can/Makefile > @@ -0,0 +1,7 @@ > +# > +# Makefile for the Bosch M_CAN controller drivers. > +# > + > +obj-$(CONFIG_CAN_M_CAN) += m_can.o > + > +ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG > diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c > new file mode 100644 > index 0000000..7bb3c05 > --- /dev/null > +++ b/drivers/net/can/m_can/m_can.c > @@ -0,0 +1,1136 @@ > +/* > + * CAN bus driver for Bosch M_CAN controller > + * > + * Copyright (C) 2014 Freescale Semiconductor, Inc. > + * Dong Aisheng <b29396@xxxxxxxxxxxxx> > + * > + * Bosch M_CAN user manual can be obtained from: > + * http://www.bosch-semiconductors.de/media/pdf_1/ipmodules_1/m_can/ > + * mcan_users_manual_v302.pdf > + * > + * This file is licensed under the terms of the GNU General Public > + * License version 2. This program is licensed "as is" without any > + * warranty of any kind, whether express or implied. > + */ > + > +#include <linux/clk.h> > +#include <linux/delay.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/can/dev.h> > + > +/* napi related */ > +#define M_CAN_NAPI_WEIGHT 64 > + > +/* message ram configuration data length */ > +#define MRAM_CFG_LEN 8 > + > +/* registers definition */ > +enum m_can_reg { > + M_CAN_CREL = 0x0, > + M_CAN_ENDN = 0x4, > + M_CAN_CUST = 0x8, > + M_CAN_FBTP = 0xc, > + M_CAN_TEST = 0x10, > + M_CAN_RWD = 0x14, > + M_CAN_CCCR = 0x18, > + M_CAN_BTP = 0x1c, > + M_CAN_TSCC = 0x20, > + M_CAN_TSCV = 0x24, > + M_CAN_TOCC = 0x28, > + M_CAN_TOCV = 0x2c, > + M_CAN_ECR = 0x40, > + M_CAN_PSR = 0x44, > + M_CAN_IR = 0x50, > + M_CAN_IE = 0x54, > + M_CAN_ILS = 0x58, > + M_CAN_ILE = 0x5c, > + M_CAN_GFC = 0x80, > + M_CAN_SIDFC = 0x84, > + M_CAN_XIDFC = 0x88, > + M_CAN_XIDAM = 0x90, > + M_CAN_HPMS = 0x94, > + M_CAN_NDAT1 = 0x98, > + M_CAN_NDAT2 = 0x9c, > + M_CAN_RXF0C = 0xa0, > + M_CAN_RXF0S = 0xa4, > + M_CAN_RXF0A = 0xa8, > + M_CAN_RXBC = 0xac, > + M_CAN_RXF1C = 0xb0, > + M_CAN_RXF1S = 0xb4, > + M_CAN_RXF1A = 0xb8, > + M_CAN_RXESC = 0xbc, > + M_CAN_TXBC = 0xc0, > + M_CAN_TXFQS = 0xc4, > + M_CAN_TXESC = 0xc8, > + M_CAN_TXBRP = 0xcc, > + M_CAN_TXBAR = 0xd0, > + M_CAN_TXBCR = 0xd4, > + M_CAN_TXBTO = 0xd8, > + M_CAN_TXBCF = 0xdc, > + M_CAN_TXBTIE = 0xe0, > + M_CAN_TXBCIE = 0xe4, > + M_CAN_TXEFC = 0xf0, > + M_CAN_TXEFS = 0xf4, > + M_CAN_TXEFA = 0xf8, > +}; > + > +/* m_can lec values */ > +enum m_can_lec_type { > + LEC_NO_ERROR = 0, > + LEC_STUFF_ERROR, > + LEC_FORM_ERROR, > + LEC_ACK_ERROR, > + LEC_BIT1_ERROR, > + LEC_BIT0_ERROR, > + LEC_CRC_ERROR, > + LEC_UNUSED, > +}; > + > +/* 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) > + > +/* Bit Timing & Prescaler Register (BTP) */ > +#define BTR_BRP_MASK 0x3ff > +#define BTR_BRP_SHIFT 16 > +#define BTR_TSEG1_SHIFT 8 > +#define BTR_TSEG1_MASK (0x3f << BTR_TSEG1_SHIFT) > +#define BTR_TSEG2_SHIFT 4 > +#define BTR_TSEG2_MASK (0xf << BTR_TSEG2_SHIFT) > +#define BTR_SJW_SHIFT 0 > +#define BTR_SJW_MASK 0xf > + > +/* Error Counter Register(ECR) */ > +#define ECR_RP BIT(15) > +#define ECR_REC_SHIFT 8 > +#define ECR_REC_MASK (0x7f << ECR_REC_SHIFT) > +#define ECR_TEC_SHIFT 0 > +#define ECR_TEC_MASK 0xff > + > +/* Protocol Status Register(PSR) */ > +#define PSR_BO BIT(7) > +#define PSR_EW BIT(6) > +#define PSR_EP BIT(5) > +#define PSR_LEC_MASK 0x7 > + > +/* Interrupt Register(IR) */ > +#define IR_ALL_INT 0xffffffff > +#define IR_STE BIT(31) > +#define IR_FOE BIT(30) > +#define IR_ACKE BIT(29) > +#define IR_BE BIT(28) > +#define IR_CRCE BIT(27) > +#define IR_WDI BIT(26) > +#define IR_BO BIT(25) > +#define IR_EW BIT(24) > +#define IR_EP BIT(23) > +#define IR_ELO BIT(22) > +#define IR_BEU BIT(21) > +#define IR_BEC BIT(20) > +#define IR_DRX BIT(19) > +#define IR_TOO BIT(18) > +#define IR_MRAF BIT(17) > +#define IR_TSW BIT(16) > +#define IR_TEFL BIT(15) > +#define IR_TEFF BIT(14) > +#define IR_TEFW BIT(13) > +#define IR_TEFN BIT(12) > +#define IR_TFE BIT(11) > +#define IR_TCF BIT(10) > +#define IR_TC BIT(9) > +#define IR_HPM BIT(8) > +#define IR_RF1L BIT(7) > +#define IR_RF1F BIT(6) > +#define IR_RF1W BIT(5) > +#define IR_RF1N BIT(4) > +#define IR_RF0L BIT(3) > +#define IR_RF0F BIT(2) > +#define IR_RF0W BIT(1) > +#define IR_RF0N BIT(0) > +#define IR_ERR_STATE (IR_BO | IR_EW | IR_EP) > +#define IR_ERR_BUS (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE | \ > + IR_WDI | IR_ELO | IR_BEU | IR_BEC | IR_TOO | IR_MRAF | \ > + IR_TSW | IR_TEFL | IR_RF1L | IR_RF0L) > +#define IR_ERR_ALL (IR_ERR_STATE | IR_ERR_BUS) > + > +/* Interrupt Line Select (ILS) */ > +#define ILS_ALL_INT0 0x0 > +#define ILS_ALL_INT1 0xFFFFFFFF > + > +/* Interrupt Line Enable (ILE) */ > +#define ILE_EINT0 BIT(0) > +#define ILE_EINT1 BIT(1) > + > +/* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */ > +#define RXFC_FWM_OFF 24 > +#define RXFC_FWM_MASK 0x7f > +#define RXFC_FWM_1 (1 << RXFC_FWM_OFF) > +#define RXFC_FS_OFF 16 > +#define RXFC_FS_MASK 0x7f > + > +/* Rx FIFO 0/1 Status (RXF0S/RXF1S) */ > +#define RXFS_RFL BIT(25) > +#define RXFS_FF BIT(24) > +#define RXFS_FPI_OFF 16 > +#define RXFS_FPI_MASK 0x3f0000 > +#define RXFS_FGI_OFF 8 > +#define RXFS_FGI_MASK 0x3f00 > +#define RXFS_FFL_MASK 0x7f > + > +/* Tx Buffer Configuration(TXBC) */ > +#define TXBC_NDTB_OFF 16 > +#define TXBC_NDTB_MASK 0x3f > + > +/* Tx Buffer Element Size Configuration(TXESC) */ > +#define TXESC_TBDS_8BYTES 0x0 > +/* Tx Buffer Element */ > +#define TX_BUF_XTD BIT(30) > +#define TX_BUF_RTR BIT(29) > + > +/* Rx Buffer Element Size Configuration(TXESC) */ > +#define M_CAN_RXESC_8BYTES 0x0 > +/* Tx Buffer Element */ > +#define RX_BUF_ESI BIT(31) > +#define RX_BUF_XTD BIT(30) > +#define RX_BUF_RTR BIT(29) > + > +/* 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 RXB_ELEMENT_SIZE 16 > +#define TXE_ELEMENT_SIZE 8 > +#define TXB_ELEMENT_SIZE 16 > + > +/* m_can private data structure */ > +struct m_can_priv { > + struct can_priv can; /* must be the first member */ > + struct napi_struct napi; > + struct net_device *dev; > + struct device *device; > + struct clk *hclk; > + struct clk *cclk; > + void __iomem *base; > + u32 irqstatus; > + > + /* message ram configuration */ > + void __iomem *mram_base; > + u32 mram_off; > + u32 sidf_elems; > + u32 sidf_off; > + u32 xidf_elems; > + u32 xidf_off; > + u32 rxf0_elems; > + u32 rxf0_off; > + u32 rxf1_elems; > + u32 rxf1_off; > + u32 rxb_elems; > + u32 rxb_off; > + u32 txe_elems; > + u32 txe_off; > + u32 txb_elems; > + u32 txb_off; > +}; > + > +static inline u32 m_can_read(const struct m_can_priv *priv, enum m_can_reg reg) > +{ > + return readl(priv->base + reg); > +} > + > +static inline void m_can_write(const struct m_can_priv *priv, > + enum m_can_reg reg, u32 val) > +{ > + writel(val, priv->base + reg); > +} > + > +static inline void m_can_config_endisable(const struct m_can_priv *priv, > + bool enable) > +{ > + u32 cccr = m_can_read(priv, M_CAN_CCCR); > + u32 timeout = 10; > + u32 val = 0; > + > + if (enable) { > + /* enable m_can configuration */ > + m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT); > + /* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */ > + m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE); > + } else { > + m_can_write(priv, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE)); > + } > + > + /* there's a delay for module initialization */ > + if (enable) > + val = CCCR_INIT | CCCR_CCE; > + > + while ((m_can_read(priv, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) > + != val) { > + if (timeout == 0) { > + netdev_warn(priv->dev, "Failed to init module\n"); > + return; > + } > + timeout--; > + udelay(1); > + } > +} > + > +static void m_can_enable_all_interrupts(const struct m_can_priv *priv) ...inline... > +{ > + m_can_write(priv, M_CAN_ILE, ILE_EINT0 | ILE_EINT1); > +} > + > +static void m_can_disable_all_interrupts(const struct m_can_priv *priv) ...inline... > +{ > + m_can_write(priv, M_CAN_ILE, 0x0); > +} > + > +static void m_can_read_fifo(const struct net_device *dev, struct can_frame *cf, > + u32 rxfs) > +{ > + struct m_can_priv *priv = netdev_priv(dev); > + u32 flags, fgi; > + void __iomem *fifo_addr; > + > + fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_OFF; Just for curiosity, what do the fgi bits tell us? > + fifo_addr = priv->mram_base + priv->rxf0_off + fgi * RXF0_ELEMENT_SIZE; > + flags = readl(fifo_addr); What about a function introducing a function? static inline u32 m_can_fifo_read(const struct m_can_priv *priv priv, u32 fgi, unsgined int offset) > + if (flags & RX_BUF_XTD) > + cf->can_id = (flags & CAN_EFF_MASK) | CAN_EFF_FLAG; > + else > + cf->can_id = (flags >> 18) & CAN_SFF_MASK; > + > + if (flags & RX_BUF_RTR) { > + cf->can_id |= CAN_RTR_FLAG; > + } else { > + flags = readl(fifo_addr + 0x4); > + cf->can_dlc = get_can_dlc((flags >> 16) & 0x0F); > + *(u32 *)(cf->data + 0) = readl(fifo_addr + 0x8); > + *(u32 *)(cf->data + 4) = readl(fifo_addr + 0xC); > + } > + > + /* acknowledge rx fifo 0 */ > + m_can_write(priv, M_CAN_RXF0A, fgi); > +} > + > +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; > + u32 num_rx_pkts = 0; > + u32 rxfs; > + > + rxfs = m_can_read(priv, M_CAN_RXF0S); > + if (!(rxfs & RXFS_FFL_MASK)) { > + netdev_dbg(dev, "no messages in fifo0\n"); > + return 0; > + } > + > + while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) { > + if (rxfs & RXFS_RFL) > + netdev_warn(dev, "Rx FIFO 0 Message Lost\n"); > + > + skb = alloc_can_skb(dev, &frame); > + if (!skb) { > + stats->rx_dropped++; > + return 0; > + } > + > + m_can_read_fifo(dev, frame, rxfs); > + > + stats->rx_packets++; > + stats->rx_bytes += frame->can_dlc; > + > + netif_receive_skb(skb); > + > + quota--; > + num_rx_pkts++; > + rxfs = m_can_read(priv, M_CAN_RXF0S); > + }; > + > + can_led_event(dev, CAN_LED_EVENT_RX); > + > + return num_rx_pkts; > +} > + > +static int m_can_handle_lost_msg(struct net_device *dev) > +{ > + struct net_device_stats *stats = &dev->stats; > + struct sk_buff *skb; > + struct can_frame *frame; > + > + netdev_err(dev, "msg lost in rxf0\n"); > + > + stats->rx_errors++; > + stats->rx_over_errors++; > + > + skb = alloc_can_err_skb(dev, &frame); > + if (unlikely(!skb)) > + return 0; > + > + frame->can_id |= CAN_ERR_CRTL; > + frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; > + > + netif_receive_skb(skb); > + > + return 1; > +} > + > +static int m_can_handle_lec_err(struct net_device *dev, > + enum m_can_lec_type lec_type) > +{ > + struct m_can_priv *priv = netdev_priv(dev); > + struct net_device_stats *stats = &dev->stats; > + struct can_frame *cf; > + struct sk_buff *skb; > + > + /* early exit if no lec update */ > + if (lec_type == LEC_UNUSED) > + return 0; > + > + priv->can.can_stats.bus_error++; > + stats->rx_errors++; > + > + /* propagate the error condition to the CAN stack */ > + skb = alloc_can_err_skb(dev, &cf); > + if (unlikely(!skb)) > + return 0; > + > + /* > + * check for 'last error code' which tells us the > + * type of the last error to occur on the CAN bus > + */ > + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; > + cf->data[2] |= CAN_ERR_PROT_UNSPEC; > + > + switch (lec_type) { > + case LEC_STUFF_ERROR: > + netdev_dbg(dev, "stuff error\n"); > + cf->data[2] |= CAN_ERR_PROT_STUFF; > + break; > + case LEC_FORM_ERROR: > + netdev_dbg(dev, "form error\n"); > + cf->data[2] |= CAN_ERR_PROT_FORM; > + break; > + case LEC_ACK_ERROR: > + netdev_dbg(dev, "ack error\n"); > + cf->data[3] |= (CAN_ERR_PROT_LOC_ACK | > + CAN_ERR_PROT_LOC_ACK_DEL); > + break; > + case LEC_BIT1_ERROR: > + netdev_dbg(dev, "bit1 error\n"); > + cf->data[2] |= CAN_ERR_PROT_BIT1; > + break; > + case LEC_BIT0_ERROR: > + netdev_dbg(dev, "bit0 error\n"); > + cf->data[2] |= CAN_ERR_PROT_BIT0; > + break; > + case LEC_CRC_ERROR: > + netdev_dbg(dev, "CRC error\n"); > + cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ | > + CAN_ERR_PROT_LOC_CRC_DEL); > + break; > + default: > + break; > + } > + > + stats->rx_packets++; > + stats->rx_bytes += cf->can_dlc; > + netif_receive_skb(skb); > + > + return 1; > +} > + > +static int m_can_get_berr_counter(const struct net_device *dev, > + struct can_berr_counter *bec) > +{ > + struct m_can_priv *priv = netdev_priv(dev); > + unsigned int ecr; > + > + clk_prepare_enable(priv->hclk); > + clk_prepare_enable(priv->cclk); Please check the return values of clk_prepare_enable() > + > + ecr = m_can_read(priv, M_CAN_ECR); > + bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT; > + bec->txerr = ecr & ECR_TEC_MASK; > + > + clk_disable_unprepare(priv->hclk); > + clk_disable_unprepare(priv->cclk); > + > + return 0; > +} > + > +static int m_can_handle_state_change(struct net_device *dev, > + enum can_state new_state) > +{ > + struct m_can_priv *priv = netdev_priv(dev); > + struct net_device_stats *stats = &dev->stats; > + struct can_frame *cf; > + struct sk_buff *skb; > + struct can_berr_counter bec; > + unsigned int ecr; > + > + switch (new_state) { > + case CAN_STATE_ERROR_ACTIVE: > + /* error warning state */ > + priv->can.can_stats.error_warning++; > + priv->can.state = CAN_STATE_ERROR_WARNING; > + break; > + case CAN_STATE_ERROR_PASSIVE: > + /* error passive state */ > + priv->can.can_stats.error_passive++; > + priv->can.state = CAN_STATE_ERROR_PASSIVE; > + break; > + case CAN_STATE_BUS_OFF: > + /* bus-off state */ > + priv->can.state = CAN_STATE_BUS_OFF; > + m_can_disable_all_interrupts(priv); > + can_bus_off(dev); > + break; > + default: > + break; > + } > + > + /* propagate the error condition to the CAN stack */ > + skb = alloc_can_err_skb(dev, &cf); > + if (unlikely(!skb)) > + return 0; > + > + m_can_get_berr_counter(dev, &bec); > + > + switch (new_state) { > + case CAN_STATE_ERROR_ACTIVE: > + /* error warning state */ > + cf->can_id |= CAN_ERR_CRTL; > + cf->data[1] = (bec.txerr > bec.rxerr) ? > + CAN_ERR_CRTL_TX_WARNING : > + CAN_ERR_CRTL_RX_WARNING; > + cf->data[6] = bec.txerr; > + cf->data[7] = bec.rxerr; > + break; > + case CAN_STATE_ERROR_PASSIVE: > + /* error passive state */ > + cf->can_id |= CAN_ERR_CRTL; > + ecr = m_can_read(priv, M_CAN_ECR); > + if (ecr & ECR_RP) > + cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE; > + if (bec.txerr > 127) > + cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE; > + cf->data[6] = bec.txerr; > + cf->data[7] = bec.rxerr; > + break; > + case CAN_STATE_BUS_OFF: > + /* bus-off state */ > + cf->can_id |= CAN_ERR_BUSOFF; > + break; > + default: > + break; > + } > + > + stats->rx_packets++; > + stats->rx_bytes += cf->can_dlc; > + netif_receive_skb(skb); > + > + return 1; > +} > + > +static int m_can_handle_state_errors(struct net_device *dev, u32 psr) > +{ > + struct m_can_priv *priv = netdev_priv(dev); > + int work_done = 0; > + > + if ((psr & PSR_EW) && > + (priv->can.state != CAN_STATE_ERROR_WARNING)) { > + netdev_dbg(dev, "entered error warning state\n"); > + work_done += m_can_handle_state_change(dev, > + CAN_STATE_ERROR_WARNING); > + } > + > + if ((psr & PSR_EP) && > + (priv->can.state != CAN_STATE_ERROR_PASSIVE)) { > + netdev_dbg(dev, "entered error warning state\n"); > + work_done += m_can_handle_state_change(dev, > + CAN_STATE_ERROR_PASSIVE); > + } > + > + if ((psr & PSR_BO) && > + (priv->can.state != CAN_STATE_BUS_OFF)) { > + netdev_dbg(dev, "entered error warning state\n"); > + work_done += m_can_handle_state_change(dev, > + CAN_STATE_BUS_OFF); > + } > + > + return work_done; > +} > + > +static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus, > + u32 psr) > +{ > + int work_done = 0; > + > + if (irqstatus & IR_RF0L) > + work_done += m_can_handle_lost_msg(dev); > + > + /* handle lec errors on the bus */ > + if (psr & LEC_UNUSED) > + work_done += m_can_handle_lec_err(dev, > + psr & LEC_UNUSED); > + > + /* other unproccessed error interrupts */ > + if (irqstatus & IR_WDI) > + netdev_err(dev, "Message RAM Watchdog event due to missing READY\n"); > + if (irqstatus & IR_TOO) > + netdev_err(dev, "Timeout reached\n"); > + if (irqstatus & IR_MRAF) > + netdev_err(dev, "Message RAM access failure occurred\n"); > + > + return work_done; > +} > + > +static int m_can_poll(struct napi_struct *napi, int quota) > +{ > + struct net_device *dev = napi->dev; > + struct m_can_priv *priv = netdev_priv(dev); > + int work_done = 0; > + u32 irqstatus, psr; > + > + irqstatus = priv->irqstatus | m_can_read(priv, M_CAN_IR); > + if (!irqstatus) > + goto end; > + > + psr = m_can_read(priv, M_CAN_PSR); > + if (irqstatus & IR_ERR_STATE) > + work_done += m_can_handle_state_errors(dev, psr); > + > + if (irqstatus & IR_ERR_BUS) > + work_done += m_can_handle_bus_errors(dev, irqstatus, psr); > + > + if (irqstatus & IR_RF0N) > + /* handle events corresponding to receive message objects */ > + work_done += m_can_do_rx_poll(dev, (quota - work_done)); > + > + if (work_done < quota) { > + napi_complete(napi); > + m_can_enable_all_interrupts(priv); > + } > + > +end: > + return work_done; > +} > + > +static irqreturn_t m_can_isr(int irq, void *dev_id) > +{ > + struct net_device *dev = (struct net_device *)dev_id; > + struct m_can_priv *priv = netdev_priv(dev); > + struct net_device_stats *stats = &dev->stats; > + u32 ir; > + > + ir = m_can_read(priv, M_CAN_IR); > + if (!ir) > + return IRQ_NONE; > + > + /* ACK all irqs */ > + if (ir & IR_ALL_INT) > + m_can_write(priv, M_CAN_IR, ir); > + > + /* > + * schedule NAPI in case of > + * - rx IRQ > + * - state change IRQ > + * - bus error IRQ and bus error reporting > + */ > + if ((ir & IR_RF0N) || (ir & IR_ERR_ALL)) { > + priv->irqstatus = ir; > + m_can_disable_all_interrupts(priv); > + napi_schedule(&priv->napi); > + } > + > + /* transmission complete interrupt */ > + if (ir & IR_TC) { > + stats->tx_bytes += can_get_echo_skb(dev, 0); > + stats->tx_packets++; > + can_led_event(dev, CAN_LED_EVENT_TX); > + netif_wake_queue(dev); > + } > + > + return IRQ_HANDLED; > +} > + > +static const struct can_bittiming_const m_can_bittiming_const = { > + .name = KBUILD_MODNAME, > + .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */ > + .tseg1_max = 64, > + .tseg2_min = 1, /* Time segment 2 = phase_seg2 */ > + .tseg2_max = 16, > + .sjw_max = 16, > + .brp_min = 1, > + .brp_max = 1024, > + .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; > + u16 brp, sjw, tseg1, tseg2; > + u32 reg_btp; > + > + brp = bt->brp - 1; > + sjw = bt->sjw - 1; > + tseg1 = bt->prop_seg + bt->phase_seg1 - 1; > + tseg2 = bt->phase_seg2 - 1; > + 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); > + > + return 0; > +} > + > +/* > + * Configure M_CAN chip: > + * - set rx buffer/fifo element size > + * - configure rx fifo > + * - accept non-matching frame into fifo 0 > + * - configure tx buffer > + * - configure mode > + * - setup bittiming > + */ > +static void m_can_chip_config(struct net_device *dev) > +{ > + struct m_can_priv *priv = netdev_priv(dev); > + u32 cccr, test; > + > + 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); > + > + /* Accept Non-matching Frames Into FIFO 0 */ > + m_can_write(priv, M_CAN_GFC, 0x0); > + > + /* only support one Tx Buffer currently */ > + m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_OFF) | > + (priv->mram_off + priv->txb_off)); > + > + /* only support 8 bytes firstly */ > + m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_8BYTES); > + > + m_can_write(priv, M_CAN_TXEFC, 0x00010000 | > + (priv->mram_off + priv->txe_off)); > + > + /* rx fifo configuration, blocking mode, fifo size 1 */ > + m_can_write(priv, M_CAN_RXF0C, (priv->rxf0_elems << RXFC_FS_OFF) | > + RXFC_FWM_1 | (priv->mram_off + priv->rxf0_off)); > + > + m_can_write(priv, M_CAN_RXF1C, (priv->rxf1_elems << RXFC_FS_OFF) | > + RXFC_FWM_1 | (priv->mram_off + priv->rxf1_off)); > + > + cccr = m_can_read(priv, M_CAN_CCCR); > + cccr &= ~(CCCR_TEST | CCCR_MON); > + test = m_can_read(priv, M_CAN_TEST); > + test &= ~TEST_LBCK; > + > + if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) > + cccr |= CCCR_MON; > + > + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { > + cccr |= CCCR_TEST; > + test |= TEST_LBCK; > + } > + > + m_can_write(priv, M_CAN_CCCR, cccr); > + m_can_write(priv, M_CAN_TEST, test); > + > + /* enable all interrupts */ > + m_can_write(priv, M_CAN_IR, IR_ALL_INT); > + m_can_write(priv, M_CAN_IE, IR_ALL_INT); > + /* route all interrupts to INT0 */ > + m_can_write(priv, M_CAN_ILS, ILS_ALL_INT0); > + > + /* set bittiming params */ > + m_can_set_bittiming(dev); > + > + m_can_config_endisable(priv, false); > +} > + > +static void m_can_start(struct net_device *dev) > +{ > + struct m_can_priv *priv = netdev_priv(dev); > + > + /* basic m_can configuration */ > + m_can_chip_config(dev); > + > + priv->can.state = CAN_STATE_ERROR_ACTIVE; > + > + m_can_enable_all_interrupts(priv); > +} > + > +static int m_can_set_mode(struct net_device *dev, enum can_mode mode) > +{ > + switch (mode) { > + case CAN_MODE_START: > + m_can_start(dev); > + netif_wake_queue(dev); > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + return 0; > +} > + > +static void free_m_can_dev(struct net_device *dev) > +{ > + free_candev(dev); > +} > + > +static struct net_device *alloc_m_can_dev(void) > +{ > + struct net_device *dev; > + struct m_can_priv *priv; > + > + dev = alloc_candev(sizeof(struct m_can_priv), 1); > + if (!dev) > + return NULL; > + > + priv = netdev_priv(dev); > + netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT); > + > + priv->dev = dev; > + priv->can.bittiming_const = &m_can_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; Please take care of CAN_CTRLMODE_BERR_REPORTING, i.e. only enable bus the bus error interrupt if this bit is set. > + > + return dev; > +} > + > +static int m_can_open(struct net_device *dev) > +{ > + int err; > + struct m_can_priv *priv = netdev_priv(dev); > + > + clk_prepare_enable(priv->hclk); > + clk_prepare_enable(priv->cclk); please check return value > + > + /* open the can device */ > + err = open_candev(dev); > + if (err) { > + netdev_err(dev, "failed to open can device\n"); > + goto exit_open_fail; > + } > + > + /* register interrupt handler */ > + err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name, > + dev); > + if (err < 0) { > + netdev_err(dev, "failed to request interrupt\n"); > + goto exit_irq_fail; > + } > + > + /* start the m_can controller */ > + m_can_start(dev); > + > + can_led_event(dev, CAN_LED_EVENT_OPEN); > + napi_enable(&priv->napi); > + netif_start_queue(dev); > + > + return 0; > + > +exit_irq_fail: > + close_candev(dev); > +exit_open_fail: > + clk_disable_unprepare(priv->hclk); > + clk_disable_unprepare(priv->cclk); > + return err; > +} > + > +static void m_can_stop(struct net_device *dev) > +{ > + struct m_can_priv *priv = netdev_priv(dev); > + > + /* disable all interrupts */ > + m_can_disable_all_interrupts(priv); > + > + clk_disable_unprepare(priv->hclk); > + clk_disable_unprepare(priv->cclk); > + > + /* set the state as STOPPED */ > + priv->can.state = CAN_STATE_STOPPED; > +} > + > +static int m_can_close(struct net_device *dev) > +{ > + struct m_can_priv *priv = netdev_priv(dev); > + > + netif_stop_queue(dev); > + napi_disable(&priv->napi); > + m_can_stop(dev); > + free_irq(dev->irq, dev); > + close_candev(dev); > + can_led_event(dev, CAN_LED_EVENT_STOP); > + > + return 0; > +} > + > +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 flags = 0, id; > + void __iomem *fifo_addr; > + > + if (can_dropped_invalid_skb(dev, skb)) > + return NETDEV_TX_OK; > + > + netif_stop_queue(dev); > + > + if (cf->can_id & CAN_RTR_FLAG) > + flags |= TX_BUF_RTR; > + > + if (cf->can_id & CAN_EFF_FLAG) { > + id = cf->can_id & CAN_EFF_MASK; > + flags |= TX_BUF_XTD; > + } else { > + id = ((cf->can_id & CAN_SFF_MASK) << 18); > + } > + > + /* message ram configuration */ > + fifo_addr = priv->mram_base + priv->mram_off + priv->txb_off; > + writel(id | flags, fifo_addr); > + writel(cf->can_dlc << 16, fifo_addr + 0x4); > + writel(*(u32 *)(cf->data + 0), fifo_addr + 0x8); > + writel(*(u32 *)(cf->data + 4), fifo_addr + 0xc); > + > + can_put_echo_skb(skb, dev, 0); > + > + /* enable first TX buffer to start transfer */ > + m_can_write(priv, M_CAN_TXBTIE, 0x1); > + m_can_write(priv, M_CAN_TXBAR, 0x1); > + > + return NETDEV_TX_OK; > +} > + > +static const struct net_device_ops m_can_netdev_ops = { > + .ndo_open = m_can_open, > + .ndo_stop = m_can_close, > + .ndo_start_xmit = m_can_start_xmit, > +}; > + > +static int register_m_can_dev(struct net_device *dev) > +{ > + dev->flags |= IFF_ECHO; /* we support local echo */ > + dev->netdev_ops = &m_can_netdev_ops; > + > + return register_candev(dev); > +} > + > +static const struct of_device_id m_can_of_table[] = { > + { .compatible = "bosch,m_can", .data = NULL }, > + { /* sentinel */ }, > +}; > +MODULE_DEVICE_TABLE(of, m_can_of_table); > + > +static int m_can_of_parse_mram(struct platform_device *pdev, > + struct m_can_priv *priv) > +{ > + struct device_node *np = pdev->dev.of_node; > + struct resource *res; > + void __iomem *addr; > + u32 out_val[MRAM_CFG_LEN]; > + int ret; > + > + /* message ram could be shared */ > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram"); > + if (!res) > + return -ENODEV; > + > + addr = devm_ioremap(&pdev->dev, res->start, resource_size(res)); > + if (!addr) > + return -ENODEV; > + > + /* get message ram configuration */ > + ret = of_property_read_u32_array(np, "mram-cfg", > + out_val, sizeof(out_val) / 4); > + if (ret) { > + dev_err(&pdev->dev, "can not get message ram configuration\n"); > + return -ENODEV; > + } > + > + priv->mram_base = addr; > + priv->mram_off = out_val[0]; > + priv->sidf_elems = out_val[1]; > + priv->sidf_off = priv->mram_off; > + priv->xidf_elems = out_val[2]; > + priv->xidf_off = priv->sidf_off + priv->sidf_elems * SIDF_ELEMENT_SIZE; > + priv->rxf0_elems = out_val[3] & RXFC_FS_MASK; > + priv->rxf0_off = priv->xidf_off + priv->xidf_elems * XIDF_ELEMENT_SIZE; > + priv->rxf1_elems = out_val[4] & RXFC_FS_MASK; > + priv->rxf1_off = priv->rxf0_off + priv->rxf0_elems * RXF0_ELEMENT_SIZE; > + priv->rxb_elems = out_val[5]; > + priv->rxb_off = priv->rxf1_off + priv->rxf1_elems * RXF1_ELEMENT_SIZE; > + priv->txe_elems = out_val[6]; > + priv->txe_off = priv->rxb_off + priv->rxb_elems * RXB_ELEMENT_SIZE; > + priv->txb_elems = out_val[7] & TXBC_NDTB_MASK; > + priv->txb_off = priv->txe_off + priv->txe_elems * TXE_ELEMENT_SIZE; > + > + dev_dbg(&pdev->dev, "mram_base =%p mram_off =0x%x " > + "sidf %d xidf %d rxf0 %d rxf1 %d rxb %d txe %d txb %d\n", > + priv->mram_base, priv->mram_off, priv->sidf_elems, > + priv->xidf_elems, priv->rxf0_elems, priv->rxf1_elems, > + priv->rxb_elems, priv->txe_elems, priv->txb_elems); > + > + return 0; > +} > + > +static int m_can_plat_probe(struct platform_device *pdev) > +{ > + struct net_device *dev; > + struct m_can_priv *priv; > + struct resource *res; > + void __iomem *addr; > + struct clk *hclk, *cclk; > + int irq, ret; > + > + hclk = devm_clk_get(&pdev->dev, "hclk"); > + cclk = devm_clk_get(&pdev->dev, "cclk"); > + if (IS_ERR(hclk) || IS_ERR(cclk)) { > + dev_err(&pdev->dev, "no clock find\n"); > + return -ENODEV; > + } > + > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can"); > + addr = devm_ioremap_resource(&pdev->dev, res); > + irq = platform_get_irq_byname(pdev, "int0"); > + if (IS_ERR(addr) || irq < 0) > + return -EINVAL; > + > + /* allocate the m_can device */ > + dev = alloc_m_can_dev(); > + if (!dev) > + return -ENOMEM; > + > + priv = netdev_priv(dev); > + dev->irq = irq; > + priv->base = addr; > + priv->device = &pdev->dev; > + priv->hclk = hclk; > + priv->cclk = cclk; > + priv->can.clock.freq = clk_get_rate(cclk); > + > + ret = m_can_of_parse_mram(pdev, priv); > + if (ret) > + goto failed_free_dev; > + > + platform_set_drvdata(pdev, dev); > + SET_NETDEV_DEV(dev, &pdev->dev); > + > + ret = register_m_can_dev(dev); > + if (ret) { > + dev_err(&pdev->dev, "registering %s failed (err=%d)\n", > + KBUILD_MODNAME, ret); > + goto failed_free_dev; > + } > + > + devm_can_led_init(dev); > + > + dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n", > + KBUILD_MODNAME, priv->base, dev->irq); > + > + return 0; > + > +failed_free_dev: > + free_m_can_dev(dev); > + return ret; > +} > + > +static __maybe_unused int m_can_suspend(struct device *dev) > +{ > + struct net_device *ndev = dev_get_drvdata(dev); > + struct m_can_priv *priv = netdev_priv(ndev); > + > + if (netif_running(ndev)) { > + netif_stop_queue(ndev); > + netif_device_detach(ndev); > + } > + > + /* TODO: enter low power */ > + > + priv->can.state = CAN_STATE_SLEEPING; > + > + return 0; > +} > + > +static __maybe_unused int m_can_resume(struct device *dev) > +{ > + struct net_device *ndev = dev_get_drvdata(dev); > + struct m_can_priv *priv = netdev_priv(ndev); > + > + /* TODO: exit low power */ > + > + priv->can.state = CAN_STATE_ERROR_ACTIVE; > + > + if (netif_running(ndev)) { > + netif_device_attach(ndev); > + netif_start_queue(ndev); > + } > + > + return 0; > +} > + > +static void unregister_m_can_dev(struct net_device *dev) > +{ > + unregister_candev(dev); > +} > + > +static int m_can_plat_remove(struct platform_device *pdev) > +{ > + struct net_device *dev = platform_get_drvdata(pdev); > + > + unregister_m_can_dev(dev); > + platform_set_drvdata(pdev, NULL); > + > + free_m_can_dev(dev); > + > + return 0; > +} > + > +static const struct dev_pm_ops m_can_pmops = { > + SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume) > +}; > + > +static struct platform_driver m_can_plat_driver = { > + .driver = { > + .name = KBUILD_MODNAME, > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(m_can_of_table), > + .pm = &m_can_pmops, > + }, > + .probe = m_can_plat_probe, > + .remove = m_can_plat_remove, > +}; > + > +module_platform_driver(m_can_plat_driver); > + > +MODULE_AUTHOR("Dong Aisheng <b29396@xxxxxxxxxxxxx>"); > +MODULE_LICENSE("GPL v2"); > +MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller"); > 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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