On 10/19/20 5:57 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.zh...@nxp.com>
> ---
>  drivers/net/can/flexcan.c | 131 +++++++++++++++++++++++++++++++++-----
>  1 file changed, 114 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> index c0cdee904ca7..8ad5065c918f 100644
> --- a/drivers/net/can/flexcan.c
> +++ b/drivers/net/can/flexcan.c
> @@ -9,6 +9,7 @@
>  //
>  // Based on code originally by Andrey Volkov <avol...@varma-el.com>
>  
> +#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>
> @@ -203,6 +205,8 @@
>  
>  #define FLEXCAN_TIMEOUT_US           (250)
>  
> +#define FLEXCAN_IMX_SC_R_CAN(x)              (IMX_SC_R_CAN_0 + (x))

Why not move it into the appropriate svc header file?

> +
>  /* FLEXCAN hardware feature flags
>   *
>   * Below is some version info we got:
> @@ -242,6 +246,8 @@
>  #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 +353,7 @@ 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 +365,9 @@ 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 +397,7 @@ 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 +556,42 @@ static void flexcan_enable_wakeup_irq(struct 
> flexcan_priv *priv, bool enable)
>       priv->write(reg_mcr, &regs->mcr);
>  }
>  
> +static int flexcan_stop_mode_enable_scfw(struct flexcan_priv *priv, bool 
> enabled)
> +{
> +     u8 idx = priv->can_idx;
> +     u32 rsrc_id, val;
> +
> +     rsrc_id = FLEXCAN_IMX_SC_R_CAN(idx);
> +
> +     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(&regs->mcr);
>       reg_mcr |= FLEXCAN_MCR_SLF_WAK;
>       priv->write(reg_mcr, &regs->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 +600,17 @@ 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(&regs->mcr);
>       reg_mcr &= ~FLEXCAN_MCR_SLF_WAK;
> @@ -1838,7 +1879,7 @@ 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 +1924,6 @@ 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 +1931,64 @@ 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;
> +     u8 can_idx;
> +     int ret;
> +
> +     ret = of_property_read_u8(pdev->dev.of_node, "fsl,scu-index", &can_idx);
> +     if (ret < 0) {
> +             dev_dbg(&pdev->dev, "failed to get scu index\n");
> +             return ret;
> +     }
> +
> +     priv = netdev_priv(dev);
> +     priv->can_idx = can_idx;
> +
> +     /* this function could be defered 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;
> +     }

Don't print an error message on -EPROBE_DEFER.

> +
> +     return 0;
> +}
> +
> +/* flexcan_setup_stop_mode - Setup stop mode for wakeup
> + *
> + * Return: = 0 setup stop mode successfully or doesn't support this feature
> + *         < 0 fail to setup stop mode (could be defered probe)
> + */
> +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 doesn't support stop mode feature */
> +             return 0;
> +
> +     if (ret)
> +             return ret;
> +
> +     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 0;
> +}
> +
>  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, 
> },
> @@ -2040,17 +2134,19 @@ static int flexcan_probe(struct platform_device *pdev)
>               goto failed_register;
>       }
>  
> +     err = flexcan_setup_stop_mode(pdev);
> +     if (err < 0) {
> +             dev_err(&pdev->dev, "setup stop mode failed\n");
> +             goto failed_canregister;
> +     }
> +
>       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_canregister:
> +     unregister_flexcandev(dev);
>   failed_register:
>       pm_runtime_put_noidle(&pdev->dev);
>       pm_runtime_disable(&pdev->dev);
> @@ -2062,6 +2158,7 @@ static int flexcan_remove(struct platform_device *pdev)
>  {
>       struct net_device *dev = platform_get_drvdata(pdev);
>  
> +     device_set_wakeup_enable(&pdev->dev, false);

Please make this a seperate patch, as it fixes a bug.

>       unregister_flexcandev(dev);
>       pm_runtime_disable(&pdev->dev);
>       free_candev(dev);
> 

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
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