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Date: Thu, 22 Nov 2018 10:48:43 +0100
From: Marc Kleine-Budde <mkl@...gutronix.de>
To: Aisheng DONG <aisheng.dong@....com>,
Joakim Zhang <qiangqing.zhang@....com>,
"linux-can@...r.kernel.org" <linux-can@...r.kernel.org>
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 V3 1/1] can: flexcan: Add self wakeup support
On 11/21/18 4:34 AM, Aisheng DONG wrote:
>> -----Original Message-----
>> From: Joakim Zhang
> [...]
>>
>> 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: Dong Aisheng <aisheng.dong@....com>
>> Signed-off-by: Joakim Zhang <qiangqing.zhang@....com>
>> ---
>> drivers/net/can/flexcan.c | 175
>> +++++++++++++++++++++++++++++++++++---
>> 1 file changed, 163 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index
>> 3813f6708201..d21d0db8c83e 100644
>> --- a/drivers/net/can/flexcan.c
>> +++ b/drivers/net/can/flexcan.c
>> @@ -19,12 +19,17 @@
>> #include <linux/delay.h>
>> #include <linux/interrupt.h>
>> #include <linux/io.h>
>> +#include <linux/kernel.h>
>> +#include <linux/list.h>
>
> This two lines seems not neccesary
>
>> +#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/pm_runtime.h>
>> #include <linux/regulator/consumer.h>
>> +#include <linux/regmap.h>
>>
>> #define DRV_NAME "flexcan"
>>
>> @@ -132,7 +137,8 @@
>> (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 */ @@ -191,6 +197,7 @@
>> #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 {
>> @@ -255,6 +262,14 @@ 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;
>> @@ -272,6 +287,7 @@ 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);
>> @@ -295,7 +311,8 @@ 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 = { @@
>> -392,6 +409,40 @@ static void flexcan_clks_disable(const struct flexcan_priv
>> *priv)
>> clk_disable_unprepare(priv->clk_per);
>> }
>>
>> +static void flexcan_wake_mask_enable(struct flexcan_priv *priv) {
>> + struct flexcan_regs __iomem *regs = priv->regs;
>> + u32 reg_mcr;
>> +
>> + reg_mcr = priv->read(®s->mcr);
>> + reg_mcr |= FLEXCAN_MCR_WAK_MSK;
>> + priv->write(reg_mcr, ®s->mcr);
>> +}
>> +
>> +static void flexcan_wake_mask_disable(struct flexcan_priv *priv) {
>> + struct flexcan_regs __iomem *regs = priv->regs;
>> + u32 reg_mcr;
>> +
>> + reg_mcr = priv->read(®s->mcr);
>> + reg_mcr &= ~FLEXCAN_MCR_WAK_MSK;
>> + priv->write(reg_mcr, ®s->mcr);
>> +}
>> +
>
> Please combine those two functions into one, also improve the name a bit.
> e.g.
> flexcan_enable_wakeup_irq(struct flexcan_priv *priv, bool enable)
>
>> +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 int flexcan_transceiver_enable(const struct flexcan_priv *priv) {
>> if (!priv->reg_xceiver)
>> @@ -955,6 +1006,10 @@ static int flexcan_chip_start(struct net_device *dev)
>> reg_mcr |= FLEXCAN_MCR_FEN |
>> FLEXCAN_MCR_MAXMB(priv->tx_mb_idx);
>> }
>> +
>> + /* enable self wakeup */
>> + reg_mcr |= FLEXCAN_MCR_SLF_WAK;
>> +
>
> Should we check before setting as we already have a SETUP_STOP_MODE quirk?
>
>> netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
>> priv->write(reg_mcr, ®s->mcr);
>>
>> @@ -1240,6 +1295,60 @@ 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 *node;
>
> Probably gpr_np is better.
>
>> + struct flexcan_priv *priv;
>> + bool wakeup = true;
>> + 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;
>> +
>> + node = of_find_node_by_phandle(phandle);
>> + if (!node) {
>> + dev_dbg(&pdev->dev, "could not find gpr node by phandle\n");
>> + return PTR_ERR(node);
>> + }
>> +
>> + priv = netdev_priv(dev);
>> + priv->stm.gpr = syscon_node_to_regmap(node);
>> + 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(node);
>> +
>> + 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",
>> + node->full_name, priv->stm.req_gpr,
>> + priv->stm.req_bit, priv->stm.ack_gpr,
>> + priv->stm.ack_bit);
>> +
>> + device_set_wakeup_capable(&pdev->dev, wakeup);
>
> If 'wakeup' variable is not changeable, then not need use it.
>
>> +
>> + 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, },
>> @@ -1400,6 +1509,12 @@ 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");
>> + }
>> +
>> pm_runtime_put(&pdev->dev);
>>
>> dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n", @@
>> -1437,10 +1552,18 @@ static int __maybe_unused flexcan_suspend(struct
>> device *device)
>> int err = 0;
>>
>> if (netif_running(dev)) {
>> - err = flexcan_chip_disable(priv);
>> - if (err)
>> - return err;
>> - err = pm_runtime_force_suspend(device);
>> + /* 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;
>> + err = pm_runtime_force_suspend(device);
>
> This is mixed with runtime pm.
> I would suggestion you first upstream wakeup support.
> Then runtime pm later separately.
In fact this patch is based on the patch "can: flexcan: Implement CAN
Runtime PM", which is still under review, too.
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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