On 06/27/2014 12:00 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 <[email protected]> > --- > .../devicetree/bindings/net/can/m_can.txt | 29 + > drivers/net/can/Kconfig | 5 + > drivers/net/can/Makefile | 1 + > drivers/net/can/m_can.c | 867 > ++++++++++++++++++++ > 4 files changed, 902 insertions(+), 0 deletions(-) > > 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..2b22d02 > --- /dev/null > +++ b/Documentation/devicetree/bindings/net/can/m_can.txt > @@ -0,0 +1,29 @@ > +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 > +- interrupts : property with a value describing the interrupt > + number > +- clocks : clocks used by controller > +- mram-cfg : message ram configuration data, the format is > + <offset sidf_elems xidf_elems rxf1_elems rxb_elems txe_elems txb_elems> > + The 'offset' is the address offset inside the message ram. This is usually > set > + if you're using the shared message ram while the other part is used by > another > + m_can controller. > + The left cell are all the number of each elements inside the message ram. > + Please refer to 2.4.1 Message RAM Con.guration in Bosch M_CAN user mannual > + for each elements definition. > + > +Example: > +canfd1: canfd@020e8000 { > + compatible = "bosch,m_can"; > + reg = <0x020e8000 0x4000>, <0x02298000 0x4000>; > + reg-names = "canfd", "message_ram"; > + interrupts = <0 114 0x04>; > + clocks = <&clks IMX6SX_CLK_CANFD>; > + mram-cfg = <0x0 0 0 32 32 32 0 1>; > + status = "disabled"; > +}; > diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig > index 4168822..3fd1c4a 100644 > --- a/drivers/net/can/Kconfig > +++ b/drivers/net/can/Kconfig > @@ -137,6 +137,11 @@ config CAN_XILINXCAN > Xilinx CAN driver. This driver supports both soft AXI CAN IP and > Zynq CANPS IP. > > +config CAN_M_CAN > + tristate "Bosch M_CAN devices" > + ---help--- > + Say Y here if you want to support for Bosch M_CAN controller. > + > source "drivers/net/can/mscan/Kconfig" > > source "drivers/net/can/sja1000/Kconfig" > diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile > index 1697f22..69dee2c 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.o > 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.c b/drivers/net/can/m_can.c > new file mode 100644 > index 0000000..61e9a8e > --- /dev/null > +++ b/drivers/net/can/m_can.c > @@ -0,0 +1,867 @@ > +/* > + * CAN bus driver for Bosch M_CAN controller > + * > + * Copyright (C) 2014 Freescale Semiconductor, Inc. > + * Dong Aisheng <[email protected]> > + * > + * 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/if_arp.h> > +#include <linux/if_ether.h> > +#include <linux/interrupt.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/list.h> > +#include <linux/module.h> > +#include <linux/netdevice.h> > +#include <linux/of.h> > +#include <linux/of_device.h> > +#include <linux/pinctrl/consumer.h> > +#include <linux/platform_device.h> > + > +#include <linux/can/dev.h> > + > +/* napi related */ > +#define M_CAN_NAPI_WEIGHT 64 > + > +/* 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, > +}; > + > +/* CC Control Register(CCCR) */ > +#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 > + > +/* 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_ALL (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE | \ > + IR_WDI | IR_BO | IR_EW | IR_EP | IR_ELO | IR_BEU | \ > + IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \ > + IR_RF0L) > + > +/* 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 *clk; > + 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, val; > + > + 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 */ > + val = enable ? CCCR_INIT | CCCR_CCE : 0;
nitpick:
If you declare:
u32 val = 0;
you can use a more readable:
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(struct m_can_priv *priv, bool enable)
> +{
> + m_can_write(priv, M_CAN_ILE, enable ? 0x00000003 : 0x0);
> +}
Can you make this two functions, I personally don't like to call a
function: *_enable_* if is actually disabled something. Please make use
of the defines instead of using 0x3.
> +
> +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 rxfs, flags, fgi;
> + u32 num_rx_pkts = 0;
> +
> + 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)) {
> + netdev_dbg(dev, "fifo0 status 0x%x\n", rxfs);
Please remove the netdev_dbg(), once the driver is stable it should be
of no use.
> + if (rxfs & RXFS_RFL)
> + netdev_warn(dev, "Rx FIFO 0 Message Lost\n");
What does that mean? Can you still rx the message if it's lost?
> +
> + skb = alloc_can_skb(dev, &frame);
> + if (!skb) {
> + stats->rx_dropped++;
> + return -ENOMEM;
Have a look at the user of m_can_do_rx_poll() and how it makes use of
the return value.
> + }
> +
> + fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_OFF;
BTW: Is this a _real_ fifo? Or evolution of the c_can/d_can interface
where it's not a fifo at all.
> + flags = readl(priv->mram_base + priv->rxf0_off + fgi * 16);
> + if (flags & RX_BUF_XTD)
> + frame->can_id = (flags & CAN_EFF_MASK) | CAN_EFF_FLAG;
> + else
> + frame->can_id = (flags >> 18) & CAN_SFF_MASK;
> + netdev_dbg(dev, "R0 0x%x\n", flags);
please remove dbg
> +
> + if (flags & RX_BUF_RTR) {
> + frame->can_id |= CAN_RTR_FLAG;
> + } else {
> + flags = readl(priv->mram_base +
> + priv->rxf0_off + fgi * 16 + 0x4);
> + frame->can_dlc = get_can_dlc((flags >> 16) & 0x0F);
> + netdev_dbg(dev, "R1 0x%x\n", flags);
please remove
> +
> + *(u32 *)(frame->data + 0) = readl(priv->mram_base +
> + priv->rxf0_off + fgi * 16 + 0x8);
> + *(u32 *)(frame->data + 4) = readl(priv->mram_base +
> + priv->rxf0_off + fgi * 16 + 0xC);
can you create a wrapper function to hide the pointer arithmetics here?
Somethig like m_can_read_fifo()
> + netdev_dbg(dev, "R2 0x%x\n", *(u32 *)(frame->data + 0));
> + netdev_dbg(dev, "R3 0x%x\n", *(u32 *)(frame->data + 4));
> + }
> +
> + /* acknowledge rx fifo 0 */
> + m_can_write(priv, M_CAN_RXF0A, fgi);
> +
> + netif_receive_skb(skb);
> + netdev_dbg(dev, "new packet received\n");
> +
> + stats->rx_packets++;
> + stats->rx_bytes += frame->can_dlc;
Please move the stats handling in front of netif_receive_skb() as the
skb and thus frame is not a valid pointer anymore.
> +
> + can_led_event(dev, CAN_LED_EVENT_RX);
Please move out of the loop so that it is just called once (if a CAN
frame is rx'ed) per m_can_do_rx_poll().
> +
> + quota--;
> + num_rx_pkts++;
> + rxfs = m_can_read(priv, M_CAN_RXF0S);
> + };
> +
> + return num_rx_pkts;
> +}
> +
> +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);
> + u32 work_done = 0;
Pleas make work_done a int, as it is retuned by this funtcion.
> + u32 irqstatus;
> +
> + irqstatus = m_can_read(priv, M_CAN_IR);
> + if (irqstatus)
> + netdev_dbg(dev, "irqstatus updated! new 0x%x old 0x%x rxf0s
> 0x%x\n",
> + irqstatus, priv->irqstatus,
> + m_can_read(priv, M_CAN_RXF0S));
Please remove debug.
> +
> + irqstatus = irqstatus | priv->irqstatus;
> + if (!irqstatus)
> + goto end;
> +
> + 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);
> + /* enable all IRQs */
> + m_can_enable_all_interrupts(priv, true);
> + }
> +
> +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;
> +
> + netdev_dbg(dev, "ir 0x%x rxfs0 0x%x\n", ir,
> + m_can_read(priv, M_CAN_RXF0S));
please remove
> +
> + /* ACK all irqs */
> + if (ir & IR_ALL_INT)
> + m_can_write(priv, M_CAN_IR, ir);
> +
> + if (ir & IR_ERR_ALL) {
> + netdev_dbg(dev, "bus error\n");
> + /* TODO: handle bus error */
> + }
> +
> + /* save irqstatus for later using */
> + priv->irqstatus = ir;
> +
> + /*
> + * schedule NAPI in case of
> + * - rx IRQ
> + * - state change IRQ(TODO)
> + * - bus error IRQ and bus error reporting (TODO)
> + */
> + if (ir & IR_RF0N) {
> + m_can_enable_all_interrupts(priv, false);
> + napi_schedule(&priv->napi);
> + }
> +
> + /* FIFO overflow */
> + if (ir & IR_RF0L) {
> + dev->stats.rx_over_errors++;
> + dev->stats.rx_errors++;
> + }
> +
> + /* transmission complete interrupt */
> + if (ir & IR_TC) {
> + netdev_dbg(dev, "tx complete\n");
> + 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
> + * - setup bittiming
> + * - TODO:
> + * 1) other working modes support like monitor, loopback...
> + * 2) lec error status report enable
> + */
> +static void m_can_chip_config(struct net_device *dev)
> +{
> + struct m_can_priv *priv = netdev_priv(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);
> +
> + /* 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));
> +
> + /* enable all interrupts */
> + m_can_write(priv, M_CAN_IR, IR_ALL_INT);
> + m_can_write(priv, M_CAN_IE, IR_ALL_INT);
> + m_can_write(priv, M_CAN_ILS, 0xFFFF0000);
^^^^^^^^^^
A define would be nice.
> +
> + /* 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;
> +
> + /* enable status change, error and module interrupts */
> + m_can_enable_all_interrupts(priv, true);
> +}
> +
> +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 int m_can_get_berr_counter(const struct net_device *dev,
> + struct can_berr_counter *bec)
> +{
> + /* TODO */
> +
> + 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;
Are you taking care of all ctrlmodes you claim to support here?
> +
> + 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->clk);
> +
> + /* 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->clk);
> + return err;
> +}
> +
> +static void m_can_stop(struct net_device *dev)
> +{
> + struct m_can_priv *priv = netdev_priv(dev);
> +
> + /* disable all interrupts */
> + m_can_enable_all_interrupts(priv, false);
> +
> + /* 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 *frame = (struct can_frame *)skb->data;
> + u32 flags = 0, id;
> +
> + if (can_dropped_invalid_skb(dev, skb))
> + return NETDEV_TX_OK;
> +
> + netif_stop_queue(dev);
> +
> + if (frame->can_id & CAN_RTR_FLAG)
> + flags |= TX_BUF_RTR;
> +
> + if (frame->can_id & CAN_EFF_FLAG) {
> + id = frame->can_id & CAN_EFF_MASK;
> + flags |= TX_BUF_XTD;
> + } else {
> + id = ((frame->can_id & CAN_SFF_MASK) << 18);
> + }
> +
> + /* message ram configuration */
> + writel(id | flags,
> + priv->mram_base + priv->mram_off + priv->txb_off);
> + writel(frame->can_dlc << 16,
> + priv->mram_base + priv->mram_off + priv->txb_off + 0x4);
> + writel(*(u32 *)(frame->data + 0),
> + priv->mram_base + priv->mram_off + priv->txb_off + 0x8);
> + writel(*(u32 *)(frame->data + 4),
> + priv->mram_base + priv->mram_off + priv->txb_off + 0xc);
Here an inline function to hide the details of pointer arithmetics would
be nice.
> +
> + can_put_echo_skb(skb, dev, 0);
> +
> + /* enable first TX buffer to start transfer */
> + m_can_write(priv, M_CAN_TXBTIE, 0x00000001);
> + m_can_write(priv, M_CAN_TXBAR, 0x00000001);
> +
> + 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[8];
> + 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 pinctrl *pinctrl;
> + struct resource *res;
> + void __iomem *addr;
> + struct clk *clk;
> + int irq, ret;
> +
> + pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
> + if (IS_ERR(pinctrl))
> + dev_warn(&pdev->dev,
> + "failed to configure pins from driver\n");
> +
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(clk)) {
> + dev_err(&pdev->dev, "no clock find\n");
> + return PTR_ERR(clk);
> + }
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "canfd");
> + addr = devm_ioremap_resource(&pdev->dev, res);
> + irq = platform_get_irq(pdev, 0);
> + 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->clk = clk;
> + priv->can.clock.freq = clk_get_rate(clk);
> +
> + 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;
> +}
> +
> +#ifdef CONFIG_PM
please remove and use __maybe_unused unstead
> +static 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 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;
> +}
> +#endif
> +
> +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 <[email protected]>");
> +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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