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Date: Fri, 16 Oct 2020 08:18:50 +0200
From: Marc Kleine-Budde <mkl@...gutronix.de>
To: Joakim Zhang <qiangqing.zhang@....com>, robh+dt@...nel.org,
shawnguo@...nel.org, s.hauer@...gutronix.de
Cc: kernel@...gutronix.de, linux-imx@....com, victor.liu@....com,
peng.fan@....com, linux-can@...r.kernel.org, pankaj.bansal@....com,
netdev@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org
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@....com>
> ---
> 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@...ma-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>
> @@ -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))
> +
> + 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...
> + } else {
...and remove the else
> + 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.
> }
>
> 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.
>
> 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 |
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