On 2020-11-13 09:42, Loic Poulain wrote:
Hi Bhaumik,
On Fri, 13 Nov 2020 at 18:12, Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
wrote:
On 2020-11-13 06:59, Loic Poulain wrote:
> Add support for resetting the device, reset can be triggered in case
> of error or manually via sysfs (/sys/bus/pci/devices/*/reset).
>
> Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx>
> ---
> drivers/bus/mhi/pci_generic.c | 117
> +++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 104 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/bus/mhi/pci_generic.c
> b/drivers/bus/mhi/pci_generic.c
> index 0c07cf5..b48c382 100644
> --- a/drivers/bus/mhi/pci_generic.c
> +++ b/drivers/bus/mhi/pci_generic.c
> @@ -8,6 +8,7 @@
> * Copyright (C) 2020 Linaro Ltd <loic.poulain@xxxxxxxxxx>
> */
>
> +#include <linux/delay.h>
> #include <linux/device.h>
> #include <linux/mhi.h>
> #include <linux/module.h>
> @@ -179,6 +180,16 @@ static const struct pci_device_id
> mhi_pci_id_table[] = {
> };
> MODULE_DEVICE_TABLE(pci, mhi_pci_id_table);
>
> +enum mhi_pci_device_status {
> + MHI_PCI_DEV_STARTED,
> +};
> +
> +struct mhi_pci_device {
> + struct mhi_controller mhi_cntrl;
> + struct pci_saved_state *pci_state;
> + unsigned long status;
> +};
> +
> static int mhi_pci_read_reg(struct mhi_controller *mhi_cntrl,
> void __iomem *addr, u32 *out)
> {
> @@ -203,6 +214,20 @@ static inline void mhi_pci_reset(struct
> mhi_controller *mhi_cntrl)
> writel(1, mhi_cntrl->regs + DEV_RESET_REG);
> }
>
> +static bool mhi_pci_is_alive(struct mhi_controller *mhi_cntrl)
> +{
> + struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
> + u16 vendor = 0;
> +
> + if (pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor))
> + return false;
> +
> + if (vendor == (u16) ~0 || vendor == 0)
> + return false;
> +
> + return true;
> +}
> +
> static int mhi_pci_claim(struct mhi_controller *mhi_cntrl,
> unsigned int bar_num, u64 dma_mask)
> {
> @@ -298,16 +323,18 @@ static int mhi_pci_probe(struct pci_dev *pdev,
> const struct pci_device_id *id)
> {
> const struct mhi_pci_dev_info *info = (struct mhi_pci_dev_info *)
> id->driver_data;
> const struct mhi_controller_config *mhi_cntrl_config;
> + struct mhi_pci_device *mhi_pdev;
> struct mhi_controller *mhi_cntrl;
> int err;
>
> dev_dbg(&pdev->dev, "MHI PCI device found: %s\n", info->name);
>
> - mhi_cntrl = mhi_alloc_controller();
> - if (!mhi_cntrl)
Not recommended.
> + mhi_pdev = devm_kzalloc(&pdev->dev, sizeof(*mhi_pdev), GFP_KERNEL);
> + if (!mhi_pdev)
> return -ENOMEM;
Why move away from the mhi_alloc_controller/mhi_free_controller pair
we
recommended for use?
Because now I don't allocate mhi controller separately, it's part of
the allocated mhi_pci_device that inherit from it. If necessary we
would need something like mhi_init_controller() to initialize the
field, but AFAIU everything needs to be zeroed.
Let's make sure we use the mhi_alloc/free_controller APIs because it
will
help us have better control in case we need track of some allocations.
Regards,
Loic
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