On 08/07/2012 01:20 PM, AnilKumar Ch wrote:
> Add Runtime PM support to C_CAN/D_CAN controller. The runtime PM
> APIs control clocks for C_CAN/D_CAN IP and prevent access to the
> register of C_CAN/D_CAN IP when clock is turned off.
>
> Signed-off-by: AnilKumar Ch <anilkumar@xxxxxx>
> ---
> This patch has been tested on AM335X EVM. Due to lack of hardware
> I am not able to test c_can functionality. I appreciate if anyone
> can test c_can functionality with this patch.
The "priv->pdev->dev" will not work for c_can/d_can which are not using
the platform driver. Options:
a) priv->dev
add a struct device pointer to the priv, and
1) guard pm_runtime_get_sync() for priv->dev == NULL
(or check if pm_runtime_get_sync copes with NULL pointer)
- or -
2) fill in the priv->dev in all other drivers (i.e. PCI)
and check if it makes sense/works to call it on PCI hardware
b) convert all other drivers, i.e. the PCI driver to create a
platform device
Without thinking long, I suggest to a) with flavour 1)
Maybe there are better solutions.
Marc
More comments inline:
>
> This patch is based on "can-next/master"
>
> Changes from v4:
> - Incorporated Vaibhav H review comments on v4.
> * Moved pm_runtime put/get_sync calls to appropriate positions.
> - This patch is from "Add DT support to C_CAN/D_CAN controller"
> patch series. Rest of the patches in this series were applied
> so this v5 contains only this patch.
>
> drivers/net/can/c_can/c_can.c | 8 ++++++++
> drivers/net/can/c_can/c_can.h | 1 +
> drivers/net/can/c_can/c_can_platform.c | 11 +++++++++++
> 3 files changed, 20 insertions(+)
>
> diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
> index eea6608..ca1151d 100644
> --- a/drivers/net/can/c_can/c_can.c
> +++ b/drivers/net/can/c_can/c_can.c
> @@ -34,6 +34,8 @@
> #include <linux/if_ether.h>
> #include <linux/list.h>
> #include <linux/io.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/platform_device.h>
>
> #include <linux/can.h>
> #include <linux/can/dev.h>
> @@ -673,6 +675,8 @@ static int c_can_get_berr_counter(const struct net_device *dev,
> unsigned int reg_err_counter;
> struct c_can_priv *priv = netdev_priv(dev);
>
> + pm_runtime_get_sync(&priv->pdev->dev);
> +
Why do you make a get_sync() here, where's the correspondning put_sync()?
> reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG);
> bec->rxerr = (reg_err_counter & ERR_CNT_REC_MASK) >>
> ERR_CNT_REC_SHIFT;
> @@ -1053,6 +1057,8 @@ static int c_can_open(struct net_device *dev)
> int err;
> struct c_can_priv *priv = netdev_priv(dev);
>
> + pm_runtime_get_sync(&priv->pdev->dev);
> +
> /* open the can device */
> err = open_candev(dev);
> if (err) {
What if open_candev() fails? Please add a jump label
exit_open_candev_fail and add thje put_sync() there.
goto exit_open_candev_fail;
> @@ -1079,6 +1085,7 @@ static int c_can_open(struct net_device *dev)
>
> exit_irq_fail:
> close_candev(dev);
exit_open_candev_fail:
> + pm_runtime_put_sync(&priv->pdev->dev);
> return err;
> }
>
> @@ -1091,6 +1098,7 @@ static int c_can_close(struct net_device *dev)
> c_can_stop(dev);
> free_irq(dev->irq, dev);
> close_candev(dev);
> + pm_runtime_put_sync(&priv->pdev->dev);
>
> return 0;
> }
> diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
> index 4e56baa..ef84439 100644
> --- a/drivers/net/can/c_can/c_can.h
> +++ b/drivers/net/can/c_can/c_can.h
> @@ -153,6 +153,7 @@ struct c_can_priv {
> struct can_priv can; /* must be the first member */
> struct napi_struct napi;
> struct net_device *dev;
> + struct platform_device *pdev;
> int tx_object;
> int current_status;
> int last_status;
> diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
> index d0a66cf..cbb1184 100644
> --- a/drivers/net/can/c_can/c_can_platform.c
> +++ b/drivers/net/can/c_can/c_can_platform.c
> @@ -32,6 +32,7 @@
> #include <linux/clk.h>
> #include <linux/of.h>
> #include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
>
> #include <linux/can/dev.h>
>
> @@ -177,7 +178,11 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
> goto exit_free_device;
> }
>
> + pm_runtime_enable(&pdev->dev);
> + pm_runtime_get_sync(&pdev->dev);
> +
> dev->irq = irq;
> + priv->pdev = pdev;
> priv->base = addr;
> priv->can.clock.freq = clk_get_rate(clk);
> priv->priv = clk;
> @@ -192,12 +197,16 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
> goto exit_free_device;
> }
>
> + pm_runtime_put_sync(&pdev->dev);
> +
> dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
> KBUILD_MODNAME, priv->base, dev->irq);
> return 0;
>
> exit_free_device:
> platform_set_drvdata(pdev, NULL);
> + pm_runtime_put_sync(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> free_c_can_dev(dev);
> exit_iounmap:
> iounmap(addr);
> @@ -226,6 +235,8 @@ static int __devexit c_can_plat_remove(struct platform_device *pdev)
> mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> release_mem_region(mem->start, resource_size(mem));
>
> + pm_runtime_put_sync(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> clk_put(priv->priv);
>
> return 0;
>
--
Pengutronix e.K. | Marc Kleine-Budde |
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