RE: [PATCH V4 1/1] can: flexcan: add self wakeup support

From: Joakim Zhang
Date: Wed Nov 21 2018 - 20:28:19 EST

Hi AIsheng,


> -----Original Message-----
> From: Aisheng DONG
> Sent: 2018年11月21日 21:02
> To: Joakim Zhang <qiangqing.zhang@xxxxxxx>; linux-can@xxxxxxxxxxxxxxx;
> mkl@xxxxxxxxxxxxxx
> Cc: wg@xxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; dl-linux-imx
> <linux-imx@xxxxxxx>
> Subject: RE: [PATCH V4 1/1] can: flexcan: add self wakeup support
>
> > -----Original Message-----
> > From: Aisheng DONG
> > Sent: Wednesday, November 21, 2018 9:00 PM
> > To: Joakim Zhang <qiangqing.zhang@xxxxxxx>; linux-can@xxxxxxxxxxxxxxx;
> > mkl@xxxxxxxxxxxxxx
> > Cc: wg@xxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; dl-linux-imx
> > <linux-imx@xxxxxxx>
> > Subject: RE: [PATCH V4 1/1] can: flexcan: add self wakeup support
> >
> > This mostly looks good to me.
> > A few minor comments
> >
>
> BTW, you should re-send the series with binding doc patch if it's still not
> merged.

It has been reviewed by: Rob Herring <robh@xxxxxxxxxx>, but still has not been merged. I will re-send the series with binding doc.

Best Regards,
Joakim Zhang

> Regards
> Dong Aisheng
>
> > > -----Original Message-----
> > > From: Joakim Zhang
> > > Sent: Wednesday, November 21, 2018 8:32 PM
> > > To: linux-can@xxxxxxxxxxxxxxx; mkl@xxxxxxxxxxxxxx
> > > Cc: wg@xxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; dl-linux-imx
> > > <linux-imx@xxxxxxx>; Aisheng DONG <aisheng.dong@xxxxxxx>; Joakim
> > Zhang
> > > <qiangqing.zhang@xxxxxxx>
> > > Subject: [PATCH V4 1/1] can: flexcan: add self wakeup support
> > >
> > > From: Aisheng Dong <aisheng.dong@xxxxxxx>
> > >
> > > If wakeup is enabled, enter stop mode, else enter disabled mode.
> > > Self wake can only work on stop mode.
> > >
> > > Starting from IMX6, the flexcan stop mode control bits is SoC
> > > specific, move it out of IP driver and parse it from devicetree.
> > >
> > > Signed-off-by: Aisheng Dong <aisheng.dong@xxxxxxx>
> > > Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx>
> > > ---
> > > drivers/net/can/flexcan.c | 163
> > > +++++++++++++++++++++++++++++++++++---
> > > 1 file changed, 154 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> > > index 8e972ef08637..83431810316e 100644
> > > --- a/drivers/net/can/flexcan.c
> > > +++ b/drivers/net/can/flexcan.c
> > > @@ -19,11 +19,14 @@
> > > #include <linux/delay.h>
> > > #include <linux/interrupt.h>
> > > #include <linux/io.h>
> > > +#include <linux/mfd/syscon.h>
> > > +#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
> > > #include <linux/module.h>
> > > #include <linux/of.h>
> > > #include <linux/of_device.h>
> > > #include <linux/platform_device.h>
> > > #include <linux/regulator/consumer.h>
> > > +#include <linux/regmap.h>
> > >
> > > #define DRV_NAME "flexcan"
> > >
> > > @@ -131,7 +134,8 @@
> > > (FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE) #define
> > > FLEXCAN_ESR_ALL_INT \
> > > (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
> > > - FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT)
> > > + FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT | \
> > > + FLEXCAN_ESR_WAK_INT)
> > >
> > > /* FLEXCAN interrupt flag register (IFLAG) bits */
> > > /* Errata ERR005829 step7: Reserve first valid MB */ @@ -190,6
> > > +194,7
> > @@
> > > #define FLEXCAN_QUIRK_USE_OFF_TIMESTAMP BIT(5) /* Use timestamp
> > > based offloading */
> > > #define FLEXCAN_QUIRK_BROKEN_PERR_STATE BIT(6) /* No interrupt
> > for
> > > error passive */
> > > #define FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN BIT(7) /* default to BE
> > > register access */
> > > +#define FLEXCAN_QUIRK_SETUP_STOP_MODE BIT(8) /* Setup stop
> > > mode to support wakeup */
> > >
> > > /* Structure of the message buffer */ struct flexcan_mb { @@
> > > -254,6
> > > +259,14 @@ struct flexcan_devtype_data {
> > > u32 quirks; /* quirks needed for different IP cores */
> > > };
> > >
> > > +struct flexcan_stop_mode {
> > > + struct regmap *gpr;
> > > + u8 req_gpr;
> > > + u8 req_bit;
> > > + u8 ack_gpr;
> > > + u8 ack_bit;
> > > +};
> > > +
> > > struct flexcan_priv {
> > > struct can_priv can;
> > > struct can_rx_offload offload;
> > > @@ -270,6 +283,7 @@ struct flexcan_priv {
> > > struct clk *clk_per;
> > > const struct flexcan_devtype_data *devtype_data;
> > > struct regulator *reg_xceiver;
> > > + struct flexcan_stop_mode stm;
> > >
> > > /* Read and Write APIs */
> > > u32 (*read)(void __iomem *addr);
> > > @@ -293,7 +307,8 @@ static const struct flexcan_devtype_data
> > > fsl_imx28_devtype_data = {
> > >
> > > static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
> > > .quirks = FLEXCAN_QUIRK_DISABLE_RXFG |
> > > FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
> > > - FLEXCAN_QUIRK_USE_OFF_TIMESTAMP |
> > > FLEXCAN_QUIRK_BROKEN_PERR_STATE,
> > > + FLEXCAN_QUIRK_USE_OFF_TIMESTAMP |
> > > FLEXCAN_QUIRK_BROKEN_PERR_STATE |
> > > + FLEXCAN_QUIRK_SETUP_STOP_MODE,
> > > };
> > >
> > > static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
> > > @@
> > > -353,6 +368,35 @@ static inline void flexcan_write_le(u32 val, void
> > > __iomem
> > > *addr)
> > > iowrite32(val, addr);
> > > }
> > >
> > > +static void flexcan_enable_wakeup_irq(struct flexcan_priv *priv,
> > > +bool
> > > +enable) {
> > > + struct flexcan_regs __iomem *regs = priv->regs;
> > > + u32 reg_mcr;
> > > +
> > > + reg_mcr = priv->read(&regs->mcr);
> > > +
> > > + if (enable)
> > > + reg_mcr |= FLEXCAN_MCR_WAK_MSK;
> > > + else
> > > + reg_mcr &= ~FLEXCAN_MCR_WAK_MSK;
> > > +
> > > + priv->write(reg_mcr, &regs->mcr);
> > > +}
> > > +
> > > +static inline void flexcan_enter_stop_mode(struct flexcan_priv *priv) {
> > > + /* enable stop request */
> > > + regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
> > > + 1 << priv->stm.req_bit, 1 << priv->stm.req_bit); }
> > > +
> > > +static inline void flexcan_exit_stop_mode(struct flexcan_priv *priv) {
> > > + /* remove stop request */
> > > + regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
> > > + 1 << priv->stm.req_bit, 0);
> > > +}
> > > +
> > > static inline void flexcan_error_irq_enable(const struct
> > > flexcan_priv *priv)
> > {
> > > struct flexcan_regs __iomem *regs = priv->regs; @@ -940,6 +984,10
> > > @@ static int flexcan_chip_start(struct net_device *dev)
> > > reg_mcr |= FLEXCAN_MCR_FEN |
> > > FLEXCAN_MCR_MAXMB(priv->tx_mb_idx);
> > > }
> > > +
> > > + if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE)
> > > + reg_mcr |= FLEXCAN_MCR_SLF_WAK;
> >
> > Please try if you can merge this into flexcan_enable_wakeup_irq().
> > If not, you can check with device_can_wakeup() as the stop parsing may fail.
> >
> > > +
> > > netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
> > > priv->write(reg_mcr, &regs->mcr);
> > >
> > > @@ -1244,6 +1292,58 @@ static void unregister_flexcandev(struct
> > > net_device
> > > *dev)
> > > unregister_candev(dev);
> > > }
> > >
> > > +static int flexcan_setup_stop_mode(struct platform_device *pdev) {
> > > + struct net_device *dev = platform_get_drvdata(pdev);
> > > + struct device_node *np = pdev->dev.of_node;
> > > + struct device_node *gpr_np;
> > > + struct flexcan_priv *priv;
> > > + phandle phandle;
> > > + u32 out_val[5];
> > > + int ret;
> > > +
> > > + if (!np)
> > > + return -EINVAL;
> > > +
> > > + /* stop mode property format is:
> > > + * <&gpr req_gpr req_bit ack_gpr ack_bit>.
> > > + */
> > > + ret = of_property_read_u32_array(np, "fsl,stop-mode", out_val, 5);
> > > + if (ret) {
> > > + dev_dbg(&pdev->dev, "no stop-mode property\n");
> > > + return ret;
> > > + }
> > > + phandle = *out_val;
> > > +
> > > + gpr_np = of_find_node_by_phandle(phandle);
> > > + if (!gpr_np) {
> > > + dev_dbg(&pdev->dev, "could not find gpr node by phandle\n");
> > > + return PTR_ERR(gpr_np);
> > > + }
> > > +
> > > + priv = netdev_priv(dev);
> > > + priv->stm.gpr = syscon_node_to_regmap(gpr_np);
> >
> > Better to put node here to cover failure case?
> >
> > Regards
> > Dong Aisheng
> >
> > > + if (IS_ERR(priv->stm.gpr)) {
> > > + dev_dbg(&pdev->dev, "could not find gpr regmap\n");
> > > + return PTR_ERR(priv->stm.gpr);
> > > + }
> > > +
> > > + of_node_put(gpr_np);
> > > +
> > > + priv->stm.req_gpr = out_val[1];
> > > + priv->stm.req_bit = out_val[2];
> > > + priv->stm.ack_gpr = out_val[3];
> > > + priv->stm.ack_bit = out_val[4];
> > > +
> > > + dev_dbg(&pdev->dev, "gpr %s req_gpr 0x%x req_bit %u ack_gpr 0x%x
> > > ack_bit %u\n",
> > > + gpr_np->full_name, priv->stm.req_gpr, priv->stm.req_bit,
> > > priv->stm.ack_gpr,
> > > + priv->stm.ack_bit);
> > > +
> > > + device_set_wakeup_capable(&pdev->dev, true);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > static const struct of_device_id flexcan_of_match[] = {
> > > { .compatible = "fsl,imx6q-flexcan", .data =
> &fsl_imx6q_devtype_data, },
> > > { .compatible = "fsl,imx28-flexcan", .data =
> > > &fsl_imx28_devtype_data, }, @@ -1396,6 +1496,12 @@ static int
> > > flexcan_probe(struct platform_device
> > > *pdev)
> > >
> > > devm_can_led_init(dev);
> > >
> > > + if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE) {
> > > + err = flexcan_setup_stop_mode(pdev);
> > > + if (err)
> > > + dev_dbg(&pdev->dev, "failed to setup stop-mode\n");
> > > + }
> > > +
> > > dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
> > > priv->regs, dev->irq);
> > >
> > > @@ -1426,9 +1532,17 @@ static int __maybe_unused
> > > flexcan_suspend(struct device *device)
> > > int err;
> > >
> > > if (netif_running(dev)) {
> > > - err = flexcan_chip_disable(priv);
> > > - if (err)
> > > - return err;
> > > + /* if wakeup is enabled, enter stop mode
> > > + * else enter disabled mode.
> > > + */
> > > + if (device_may_wakeup(device)) {
> > > + enable_irq_wake(dev->irq);
> > > + flexcan_enter_stop_mode(priv);
> > > + } else {
> > > + err = flexcan_chip_disable(priv);
> > > + if (err)
> > > + return err;
> > > + }
> > > netif_stop_queue(dev);
> > > netif_device_detach(dev);
> > > }
> > > @@ -1447,14 +1561,45 @@ static int __maybe_unused
> > > flexcan_resume(struct device *device)
> > > if (netif_running(dev)) {
> > > netif_device_attach(dev);
> > > netif_start_queue(dev);
> > > - err = flexcan_chip_enable(priv);
> > > - if (err)
> > > - return err;
> > > + if (device_may_wakeup(device)) {
> > > + flexcan_enable_wakeup_irq(priv, false);
> > > + } else {
> > > + err = flexcan_chip_enable(priv);
> > > + if (err)
> > > + return err;
> > > + }
> > > + }
> > > + return 0;
> > > +}
> > > +
> > > +static int __maybe_unused flexcan_noirq_suspend(struct device
> > > +*device) {
> > > + struct net_device *dev = dev_get_drvdata(device);
> > > + struct flexcan_priv *priv = netdev_priv(dev);
> > > +
> > > + if (netif_running(dev) && device_may_wakeup(device))
> > > + flexcan_enable_wakeup_irq(priv, true);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int __maybe_unused flexcan_noirq_resume(struct device *device) {
> > > + struct net_device *dev = dev_get_drvdata(device);
> > > + struct flexcan_priv *priv = netdev_priv(dev);
> > > +
> > > + if (netif_running(dev) && device_may_wakeup(device)) {
> > > + disable_irq_wake(dev->irq);
> > > + flexcan_exit_stop_mode(priv);
> > > }
> > > +
> > > return 0;
> > > }
> > >
> > > -static SIMPLE_DEV_PM_OPS(flexcan_pm_ops, flexcan_suspend,
> > > flexcan_resume);
> > > +static const struct dev_pm_ops flexcan_pm_ops = {
> > > + SET_SYSTEM_SLEEP_PM_OPS(flexcan_suspend, flexcan_resume)
> > > + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(flexcan_noirq_suspend,
> > > +flexcan_noirq_resume) };
> > >
> > > static struct platform_driver flexcan_driver = {
> > > .driver = {
> > > --
> > > 2.17.1