Hi Marc,
> -----Original Message-----
> From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> Sent: 2020年10月16日 14:19
> To: Joakim Zhang <qiangqing.zhang@xxxxxxx>; robh+dt@xxxxxxxxxx;
> shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx
> Cc: kernel@xxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; Ying Liu
> <victor.liu@xxxxxxx>; Peng Fan <peng.fan@xxxxxxx>;
> linux-can@xxxxxxxxxxxxxxx; Pankaj Bansal <pankaj.bansal@xxxxxxx>;
> netdev@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 5/6] can: flexcan: add CAN wakeup function for i.MX8QM
>
> On 10/16/20 3:43 PM, Joakim Zhang wrote:
> > The System Controller Firmware (SCFW) is a low-level system function
> > which runs on a dedicated Cortex-M core to provide power, clock, and
> > resource management. It exists on some i.MX8 processors. e.g. i.MX8QM
> > (QM, QP), and i.MX8QX (QXP, DX). SCU driver manages the IPC interface
> > between host CPU and the SCU firmware running on M4.
> >
> > For i.MX8QM, stop mode request is controlled by System Controller
> > Unit(SCU) firmware, this patch introduces
> > FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW quirk for this function.
> >
> > Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx>
> > ---
> > drivers/net/can/flexcan.c | 125
> > ++++++++++++++++++++++++++++++++------
> > 1 file changed, 107 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> > index e708e7bf28db..a55ea8f27f7c 100644
> > --- a/drivers/net/can/flexcan.c
> > +++ b/drivers/net/can/flexcan.c
> > @@ -9,6 +9,7 @@
> > //
> > // Based on code originally by Andrey Volkov <avolkov@xxxxxxxxxxxx>
> >
> > +#include <dt-bindings/firmware/imx/rsrc.h>
> > #include <linux/bitfield.h>
> > #include <linux/can.h>
> > #include <linux/can/dev.h>
> > @@ -17,6 +18,7 @@
> > #include <linux/can/rx-offload.h>
> > #include <linux/clk.h>
> > #include <linux/delay.h>
> > +#include <linux/firmware/imx/sci.h>
> > #include <linux/interrupt.h>
> > #include <linux/io.h>
> > #include <linux/mfd/syscon.h>
> > @@ -242,6 +244,8 @@
> > #define FLEXCAN_QUIRK_SUPPORT_FD BIT(9)
> > /* support memory detection and correction */ #define
> > FLEXCAN_QUIRK_SUPPORT_ECC BIT(10)
> > +/* Setup stop mode with SCU firmware to support wakeup */ #define
> > +FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW BIT(11)
> >
> > /* Structure of the message buffer */ struct flexcan_mb { @@ -347,6
> > +351,7 @@ struct flexcan_priv {
> > u8 mb_count;
> > u8 mb_size;
> > u8 clk_src; /* clock source of CAN Protocol Engine */
> > + u8 can_idx;
> >
> > u64 rx_mask;
> > u64 tx_mask;
> > @@ -358,6 +363,9 @@ struct flexcan_priv {
> > struct regulator *reg_xceiver;
> > struct flexcan_stop_mode stm;
> >
> > + /* IPC handle when setup stop mode by System Controller firmware(scfw)
> */
> > + struct imx_sc_ipc *sc_ipc_handle;
> > +
> > /* Read and Write APIs */
> > u32 (*read)(void __iomem *addr);
> > void (*write)(u32 val, void __iomem *addr); @@ -387,7 +395,7 @@
> > static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
> > static const struct flexcan_devtype_data fsl_imx8qm_devtype_data = {
> > .quirks = FLEXCAN_QUIRK_DISABLE_RXFG |
> FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
> > FLEXCAN_QUIRK_USE_OFF_TIMESTAMP |
> FLEXCAN_QUIRK_BROKEN_PERR_STATE |
> > - FLEXCAN_QUIRK_SUPPORT_FD,
> > + FLEXCAN_QUIRK_SUPPORT_FD |
> FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW,
> > };
> >
> > static struct flexcan_devtype_data fsl_imx8mp_devtype_data = { @@
> > -546,18 +554,46 @@ static void flexcan_enable_wakeup_irq(struct
> flexcan_priv *priv, bool enable)
> > priv->write(reg_mcr, ®s->mcr);
> > }
> >
> > +static int flexcan_stop_mode_enable_scfw(struct flexcan_priv *priv,
> > +bool enabled) {
> > + u8 idx = priv->can_idx;
> > + u32 rsrc_id, val;
> > +
> > + if (idx == 0)
> > + rsrc_id = IMX_SC_R_CAN_0;
> > + else if (idx == 1)
> > + rsrc_id = IMX_SC_R_CAN_1;
> > + else
> > + rsrc_id = IMX_SC_R_CAN_2;
>
> Can you introduce something like and make use of it:
>
> #define IMX_SC_R_CAN(x) (105 + (x))
OK.
> > +
> > + if (enabled)
> > + val = 1;
> > + else
> > + val = 0;
> > +
> > + /* stop mode request via scu firmware */
> > + return imx_sc_misc_set_control(priv->sc_ipc_handle, rsrc_id,
> > +IMX_SC_C_IPG_STOP, val); }
> > +
> > static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
> > {
> > struct flexcan_regs __iomem *regs = priv->regs;
> > u32 reg_mcr;
> > + int ret;
> >
> > reg_mcr = priv->read(®s->mcr);
> > reg_mcr |= FLEXCAN_MCR_SLF_WAK;
> > priv->write(reg_mcr, ®s->mcr);
> >
> > /* enable stop request */
> > - regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
> > - 1 << priv->stm.req_bit, 1 << priv->stm.req_bit);
> > + if (priv->devtype_data->quirks &
> FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW) {
> > + ret = flexcan_stop_mode_enable_scfw(priv, true);
> > + if (ret < 0)
> > + return ret;
> > + } else {
> > + regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
> > + 1 << priv->stm.req_bit, 1 << priv->stm.req_bit);
> > + }
> >
> > return flexcan_low_power_enter_ack(priv);
> > }
> > @@ -566,10 +602,17 @@ static inline int flexcan_exit_stop_mode(struct
> > flexcan_priv *priv) {
> > struct flexcan_regs __iomem *regs = priv->regs;
> > u32 reg_mcr;
> > + int ret;
> >
> > /* remove stop request */
> > - regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
> > - 1 << priv->stm.req_bit, 0);
> > + if (priv->devtype_data->quirks &
> FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW) {
> > + ret = flexcan_stop_mode_enable_scfw(priv, false);
> > + if (ret < 0)
> > + return ret;
> > + } else {
> > + regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
> > + 1 << priv->stm.req_bit, 0);
> > + }
> >
> > reg_mcr = priv->read(®s->mcr);
> > reg_mcr &= ~FLEXCAN_MCR_SLF_WAK;
> > @@ -1838,7 +1881,7 @@ static void unregister_flexcandev(struct
> net_device *dev)
> > unregister_candev(dev);
> > }
> >
> > -static int flexcan_setup_stop_mode(struct platform_device *pdev)
> > +static int flexcan_setup_stop_mode_gpr(struct platform_device *pdev)
> > {
> > struct net_device *dev = platform_get_drvdata(pdev);
> > struct device_node *np = pdev->dev.of_node; @@ -1883,11 +1926,6 @@
> > static int flexcan_setup_stop_mode(struct platform_device *pdev)
> > "gpr %s req_gpr=0x02%x req_bit=%u\n",
> > gpr_np->full_name, priv->stm.req_gpr, priv->stm.req_bit);
> >
> > - device_set_wakeup_capable(&pdev->dev, true);
> > -
> > - if (of_property_read_bool(np, "wakeup-source"))
> > - device_set_wakeup_enable(&pdev->dev, true);
> > -
> > return 0;
> >
> > out_put_node:
> > @@ -1895,6 +1933,56 @@ static int flexcan_setup_stop_mode(struct
> platform_device *pdev)
> > return ret;
> > }
> >
> > +static int flexcan_setup_stop_mode_scfw(struct platform_device *pdev)
> > +{
> > + struct net_device *dev = platform_get_drvdata(pdev);
> > + struct flexcan_priv *priv;
> > + int ret;
> > +
> > + priv = netdev_priv(dev);
> > +
> > + /* this function could be defer probe, return -EPROBE_DEFER */
> > + ret = imx_scu_get_handle(&priv->sc_ipc_handle);
> > + if (ret < 0)
> > + dev_dbg(&pdev->dev, "get ipc handle used by SCU failed\n");
> > +
> > + return ret;
> > +}
> > +
> > +/* flexcan_setup_stop_mode - Setup stop mode
> > + *
> > + * Return: 0 setup stop mode successfully or doesn't support this feature
> > + * -EPROBE_DEFER defer probe
> > + * < 0 fail to setup stop mode
> > + */
> > +static int flexcan_setup_stop_mode(struct platform_device *pdev) {
> > + struct net_device *dev = platform_get_drvdata(pdev);
> > + struct flexcan_priv *priv;
> > + int ret;
> > +
> > + priv = netdev_priv(dev);
> > +
> > + if (priv->devtype_data->quirks &
> FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW)
> > + ret = flexcan_setup_stop_mode_scfw(pdev);
> > + else if (priv->devtype_data->quirks &
> FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR)
> > + ret = flexcan_setup_stop_mode_gpr(pdev);
> > + else
> > + /* return 0 directly if stop mode is unsupport */
> > + return 0;
> > +
> > + if (ret) {
> > + dev_warn(&pdev->dev, "failed to setup stop mode\n");
>
> return here...
My thought was that, CAN still work even failed to setup stop mode. If you think it is better, I will change the way of setup stop mode, let probe failed if can't setup it successfully.
> > + } else {
>
> ...and remove the else
OK.
> > + device_set_wakeup_capable(&pdev->dev, true);
> > +
> > + if (of_property_read_bool(pdev->dev.of_node, "wakeup-source"))
> > + device_set_wakeup_enable(&pdev->dev, true);
> > + }
> > +
> > + return ret;
> > +}
> > +
> > static const struct of_device_id flexcan_of_match[] = {
> > { .compatible = "fsl,imx8qm-flexcan", .data =
> &fsl_imx8qm_devtype_data, },
> > { .compatible = "fsl,imx8mp-flexcan", .data =
> > &fsl_imx8mp_devtype_data, }, @@ -1927,7 +2015,7 @@ static int
> flexcan_probe(struct platform_device *pdev)
> > struct clk *clk_ipg = NULL, *clk_per = NULL;
> > struct flexcan_regs __iomem *regs;
> > int err, irq;
> > - u8 clk_src = 1;
> > + u8 clk_src = 1, can_idx = 0;
> > u32 clock_freq = 0;
> >
> > reg_xceiver = devm_regulator_get_optional(&pdev->dev, "xceiver"); @@
> > -1943,6 +2031,8 @@ static int flexcan_probe(struct platform_device *pdev)
> > "clock-frequency", &clock_freq);
> > of_property_read_u8(pdev->dev.of_node,
> > "fsl,clk-source", &clk_src);
> > + of_property_read_u8(pdev->dev.of_node,
> > + "fsl,can-index", &can_idx);
>
> What happens if the DT doesn't contain the can-index? Move this into the
> flexcan_setup_stop_mode_scfw() and add error handling.
Make sense.
> > }
> >
> > if (!clock_freq) {
> > @@ -2019,6 +2109,7 @@ static int flexcan_probe(struct platform_device
> *pdev)
> > priv->clk_src = clk_src;
> > priv->devtype_data = devtype_data;
> > priv->reg_xceiver = reg_xceiver;
> > + priv->can_idx = can_idx;
>
> Assign priv->can_idx in flexcan_setup_stop_mode_scfw(), too.
OK.
Best Regards,
Joakim Zhang
> >
> > if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SUPPORT_FD) {
> > priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD | @@
> -2030,6
> > +2121,10 @@ static int flexcan_probe(struct platform_device *pdev)
> > priv->can.bittiming_const = &flexcan_bittiming_const;
> > }
> >
> > + err = flexcan_setup_stop_mode(pdev);
> > + if (err == -EPROBE_DEFER)
> > + return -EPROBE_DEFER;
> > +
> > pm_runtime_get_noresume(&pdev->dev);
> > pm_runtime_set_active(&pdev->dev);
> > pm_runtime_enable(&pdev->dev);
> > @@ -2043,12 +2138,6 @@ static int flexcan_probe(struct platform_device
> *pdev)
> > of_can_transceiver(dev);
> > devm_can_led_init(dev);
> >
> > - if (priv->devtype_data->quirks &
> FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR) {
> > - err = flexcan_setup_stop_mode(pdev);
> > - if (err)
> > - dev_dbg(&pdev->dev, "failed to setup stop-mode\n");
> > - }
> > -
> > return 0;
> >
> > failed_register:
> >
>
> Marc
>
> --
> Pengutronix e.K. | Marc Kleine-Budde |
> Embedded Linux | https://www.pengutronix.de |
> Vertretung West/Dortmund | Phone: +49-231-2826-924 |
> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
