[PATCH 4/4] can: c_can: Add d_can suspend resume support
Marc Kleine-Budde
mkl at pengutronix.de
Mon Sep 3 16:01:35 EDT 2012
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 at ti.com>
> ---
> 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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