On 09/03/2012 01:52 PM, AnilKumar Ch wrote: > Adds suspend resume support to DCAN driver which enables > DCAN power down mode bit (PDR). Then DCAN will ack the local > power-down mode by setting PDA bit in STATUS register. > > Also adds a status flag to know the status of DCAN module, > whether it is opened or not. Use "ndev->flags & IFF_UP" for that. Have a look at the at91_can driver [1]. I'm not sure if you need locking here. [1] http://lxr.free-electrons.com/source/drivers/net/can/at91_can.c#L1198 > Signed-off-by: AnilKumar Ch <anilkumar@xxxxxx> > --- > drivers/net/can/c_can/c_can.c | 78 ++++++++++++++++++++++++++++++++ > drivers/net/can/c_can/c_can.h | 5 ++ > drivers/net/can/c_can/c_can_platform.c | 70 ++++++++++++++++++++++++++-- > 3 files changed, 150 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c > index c175410..36d5db4 100644 > --- a/drivers/net/can/c_can/c_can.c > +++ b/drivers/net/can/c_can/c_can.c > @@ -46,6 +46,9 @@ > #define IF_ENUM_REG_LEN 11 > #define C_CAN_IFACE(reg, iface) (C_CAN_IF1_##reg + (iface) * IF_ENUM_REG_LEN) > > +/* control extension register D_CAN specific */ > +#define CONTROL_EX_PDR BIT(8) > + > /* control register */ > #define CONTROL_TEST BIT(7) > #define CONTROL_CCE BIT(6) > @@ -65,6 +68,7 @@ > #define TEST_BASIC BIT(2) > > /* status register */ > +#define STATUS_PDA BIT(10) > #define STATUS_BOFF BIT(7) > #define STATUS_EWARN BIT(6) > #define STATUS_EPASS BIT(5) > @@ -164,6 +168,9 @@ > /* minimum timeout for checking BUSY status */ > #define MIN_TIMEOUT_VALUE 6 > > +/* Wait for ~1 sec for INIT bit */ > +#define INIT_WAIT_COUNT 1000 What unit? INIT_WAIT_MS would be a better name. > + > /* napi related */ > #define C_CAN_NAPI_WEIGHT C_CAN_MSG_OBJ_RX_NUM > > @@ -1102,6 +1109,7 @@ static int c_can_open(struct net_device *dev) > > netif_start_queue(dev); > > + priv->is_opened = true; > return 0; > > exit_irq_fail: > @@ -1126,6 +1134,7 @@ static int c_can_close(struct net_device *dev) > /* De-Initialize DCAN RAM */ > c_can_reset_ram(priv, false); > c_can_pm_runtime_put_sync(priv); > + priv->is_opened = false; > > return 0; > } > @@ -1154,6 +1163,75 @@ struct net_device *alloc_c_can_dev(void) > } > EXPORT_SYMBOL_GPL(alloc_c_can_dev); > > +#ifdef CONFIG_PM > +int c_can_power_down(struct net_device *dev) > +{ > + unsigned long time_out; > + struct c_can_priv *priv = netdev_priv(dev); > + > + if (!priv->is_opened) > + return 0; Should we add a BUG_ON(id->driver_data != BOSCH_D_CAN)? > + > + /* set `PDR` value so the device goes to power down mode */ > + priv->write_reg(priv, C_CAN_CTRL_EX_REG, > + priv->read_reg(priv, C_CAN_CTRL_EX_REG) | CONTROL_EX_PDR); Please use an intermediate variable: u32 val; val = priv->read_reg(priv, C_CAN_CTRL_EX_REG); val |= CONTROL_EX_PDR; priv->write_reg(priv, C_CAN_CTRL_EX_REG, val); > + > + /* Wait for the PDA bit to get set */ > + time_out = jiffies + msecs_to_jiffies(INIT_WAIT_COUNT); > + while (!(priv->read_reg(priv, C_CAN_STS_REG) & STATUS_PDA) && > + time_after(time_out, jiffies)) > + cpu_relax(); > + > + if (time_after(jiffies, time_out)) > + return -ETIMEDOUT; > + > + c_can_stop(dev); > + > + /* De-initialize DCAN RAM */ > + c_can_reset_ram(priv, false); > + c_can_pm_runtime_put_sync(priv); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(c_can_power_down); > + > +int c_can_power_up(struct net_device *dev) > +{ > + unsigned long time_out; > + struct c_can_priv *priv = netdev_priv(dev); > + BUG_ON? > + if (!priv->is_opened) > + return 0; > + > + c_can_pm_runtime_get_sync(priv); > + /* Initialize DCAN RAM */ > + c_can_reset_ram(priv, true); > + > + /* Clear PDR and INIT bits */ > + priv->write_reg(priv, C_CAN_CTRL_EX_REG, > + priv->read_reg(priv, C_CAN_CTRL_EX_REG) & ~CONTROL_EX_PDR); > + priv->write_reg(priv, C_CAN_CTRL_REG, > + priv->read_reg(priv, C_CAN_CTRL_REG) & ~CONTROL_INIT); > + > + /* Wait for the PDA bit to get clear */ > + time_out = jiffies + msecs_to_jiffies(INIT_WAIT_COUNT); > + while ((priv->read_reg(priv, C_CAN_STS_REG) & STATUS_PDA) && > + time_after(time_out, jiffies)) > + cpu_relax(); > + > + if (time_after(jiffies, time_out)) > + return -ETIMEDOUT; > + > + c_can_start(dev); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(c_can_power_up); > +#else > +#define c_can_power_down NULL > +#define c_can_power_up NULL These are not used, are they? > +#endif > + > void free_c_can_dev(struct net_device *dev) > { > free_candev(dev); > diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h > index 5f6339c..e5dd7ef 100644 > --- a/drivers/net/can/c_can/c_can.h > +++ b/drivers/net/can/c_can/c_can.h > @@ -24,6 +24,7 @@ > > enum reg { > C_CAN_CTRL_REG = 0, > + C_CAN_CTRL_EX_REG, > C_CAN_STS_REG, > C_CAN_ERR_CNT_REG, > C_CAN_BTR_REG, > @@ -104,6 +105,7 @@ static const u16 reg_map_c_can[] = { > > static const u16 reg_map_d_can[] = { > [C_CAN_CTRL_REG] = 0x00, > + [C_CAN_CTRL_EX_REG] = 0x02, > [C_CAN_STS_REG] = 0x04, > [C_CAN_ERR_CNT_REG] = 0x08, > [C_CAN_BTR_REG] = 0x0C, > @@ -166,6 +168,7 @@ struct c_can_priv { > unsigned int tx_echo; > void *priv; /* for board-specific data */ > u16 irqstatus; > + bool is_opened; > unsigned int instance; > void (*ram_init) (unsigned int instance, bool enable); > }; > @@ -174,5 +177,7 @@ struct net_device *alloc_c_can_dev(void); > void free_c_can_dev(struct net_device *dev); > int register_c_can_dev(struct net_device *dev); > void unregister_c_can_dev(struct net_device *dev); > +int c_can_power_up(struct net_device *dev); > +int c_can_power_down(struct net_device *dev); > > #endif /* C_CAN_H */ > diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c > index c6963b2..65ec232 100644 > --- a/drivers/net/can/c_can/c_can_platform.c > +++ b/drivers/net/can/c_can/c_can_platform.c > @@ -255,15 +255,79 @@ static int __devexit c_can_plat_remove(struct platform_device *pdev) > return 0; > } > > +#ifdef CONFIG_PM > +static int c_can_suspend(struct platform_device *pdev, pm_message_t state) > +{ > + int ret; > + struct net_device *ndev = platform_get_drvdata(pdev); > + struct c_can_priv *priv = netdev_priv(ndev); > + const struct platform_device_id *id = platform_get_device_id(pdev); Does that work on DT probed devices? You probably have to save the id->driver_data in struct c_can_priv. > + > + if (id->driver_data != BOSCH_D_CAN) { > + dev_warn(&pdev->dev, "Not supported\n"); > + return 0; > + } > + > + if (netif_running(ndev)) { > + netif_stop_queue(ndev); > + netif_device_detach(ndev); > + } > + > + ret = c_can_power_down(ndev); > + if (ret) { > + dev_err(&pdev->dev, "failed to enter power down mode\n"); netdev_err > + return ret; > + } > + > + priv->can.state = CAN_STATE_SLEEPING; > + > + return 0; > +} > + > +static int c_can_resume(struct platform_device *pdev) > +{ > + int ret; > + please remove the empty line ^^ > + struct net_device *ndev = platform_get_drvdata(pdev); > + struct c_can_priv *priv = netdev_priv(ndev); > + const struct platform_device_id *id = platform_get_device_id(pdev); > + > + if (id->driver_data != BOSCH_D_CAN) { > + dev_warn(&pdev->dev, "Not supported\n"); > + return 0; > + } > + > + ret = c_can_power_up(ndev); > + if (ret) { > + dev_err(&pdev->dev, "Still in power down mode\n"); netdev_err > + return ret; > + } > + > + priv->can.state = CAN_STATE_ERROR_ACTIVE; > + > + if (netif_running(ndev)) { > + netif_device_attach(ndev); > + netif_start_queue(ndev); > + } > + > + return 0; > +} > +#else > +#define c_can_suspend NULL > +#define c_can_resume NULL > +#endif > + > static struct platform_driver c_can_plat_driver = { > .driver = { > .name = KBUILD_MODNAME, > .owner = THIS_MODULE, > .of_match_table = of_match_ptr(c_can_of_table), > }, > - .probe = c_can_plat_probe, > - .remove = __devexit_p(c_can_plat_remove), > - .id_table = c_can_id_table, > + .probe = c_can_plat_probe, > + .remove = __devexit_p(c_can_plat_remove), > + .suspend = c_can_suspend, > + .resume = c_can_resume, > + .id_table = c_can_id_table, Please don't indent here with tab. Just stay with one space on both sides of the "=". > }; > > module_platform_driver(c_can_plat_driver); > 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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