On 01/13/2016 12:47 AM, Kishon Vijay Abraham I wrote:
> Use platform populated reset assert and deassert
> callbacks to perform reset of PCIe.
>
> Use these callbacks until a reset interface using drivers/reset
> is available for the purpose.
>
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
> ---
> drivers/pci/host/pci-dra7xx.c | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c
> index 8c36880..049083d 100644
> --- a/drivers/pci/host/pci-dra7xx.c
> +++ b/drivers/pci/host/pci-dra7xx.c
> @@ -25,6 +25,8 @@
> #include <linux/resource.h>
> #include <linux/types.h>
>
> +#include <linux/platform_data/pci-dra7xx.h>
> +
> #include "pcie-designware.h"
>
> /* PCIe controller wrapper DRA7XX configuration registers */
> @@ -329,6 +331,32 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx,
> return 0;
> }
>
> +static int dra7xx_pcie_reset(struct platform_device *pdev)
> +{
> + int ret;
> + struct device *dev = &pdev->dev;
> + struct pci_dra7xx_platform_data *pdata = pdev->dev.platform_data;
> +
> + if (!(pdata && pdata->deassert_reset && pdata->assert_reset)) {
> + dev_err(dev, "platform data for reset not found!\n");
> + return -EINVAL;
> + }
> +
> + ret = pdata->assert_reset(pdev, pdata->reset_name);
> + if (ret) {
> + dev_err(dev, "assert_reset failed: %d\n", ret);
> + return ret;
> + }
> +
> + ret = pdata->deassert_reset(pdev, pdata->reset_name);
> + if (ret) {
> + dev_err(dev, "deassert_reset failed: %d\n", ret);
> + return ret;
> + }
The only comment I have on this is the symmetry (assert_reset invocation
in driver remove). If you install and remove the module once, then the
reset stays deasserted. On Power-On-Reset, the resets by default will be
in asserted state.
regards
SUman
> +
> + return 0;
> +}
> +
> static int __init dra7xx_pcie_probe(struct platform_device *pdev)
> {
> u32 reg;
> @@ -347,6 +375,10 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev)
> enum of_gpio_flags flags;
> unsigned long gpio_flags;
>
> + ret = dra7xx_pcie_reset(pdev);
> + if (ret)
> + return ret;
> +
> dra7xx = devm_kzalloc(dev, sizeof(*dra7xx), GFP_KERNEL);
> if (!dra7xx)
> return -ENOMEM;
>
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