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Message-ID: <AM0PR04MB421154D4E5F03AC4D222F7E480DA0@AM0PR04MB4211.eurprd04.prod.outlook.com>
Date: Wed, 21 Nov 2018 13:00:22 +0000
From: Aisheng DONG <aisheng.dong@....com>
To: Joakim Zhang <qiangqing.zhang@....com>,
"linux-can@...r.kernel.org" <linux-can@...r.kernel.org>,
"mkl@...gutronix.de" <mkl@...gutronix.de>
CC: "wg@...ndegger.com" <wg@...ndegger.com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
dl-linux-imx <linux-imx@....com>
Subject: RE: [PATCH V4 1/1] can: flexcan: add self wakeup support
This mostly looks good to me.
A few minor comments
> -----Original Message-----
> From: Joakim Zhang
> Sent: Wednesday, November 21, 2018 8:32 PM
> To: linux-can@...r.kernel.org; mkl@...gutronix.de
> Cc: wg@...ndegger.com; linux-kernel@...r.kernel.org; dl-linux-imx
> <linux-imx@....com>; Aisheng DONG <aisheng.dong@....com>; Joakim
> Zhang <qiangqing.zhang@....com>
> Subject: [PATCH V4 1/1] can: flexcan: add self wakeup support
>
> From: Aisheng Dong <aisheng.dong@....com>
>
> 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@....com>
> Signed-off-by: Joakim Zhang <qiangqing.zhang@....com>
> ---
> 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(®s->mcr);
> +
> + if (enable)
> + reg_mcr |= FLEXCAN_MCR_WAK_MSK;
> + else
> + reg_mcr &= ~FLEXCAN_MCR_WAK_MSK;
> +
> + priv->write(reg_mcr, ®s->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, ®s->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
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