[U-Boot] [RESEND PATCHv4 9/9] dm: pci: add APIs for MPS and MRRS accessors

[Bin Meng]

On Mon, Mar 25, 2019 at 10:24 AM Z.q. Hou <zhiqiang.hou at nxp.com> wrote:
>
> From: Hou Zhiqiang <Zhiqiang.Hou at nxp.com>
>
> This patch introduce APIs for getting and updating the MPS
> and MRRS fields of Device capability Device control register.
>
> Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou at nxp.com>
> ---
> V4:
>  - New patch
>
>  drivers/pci/pci-uclass.c | 92 ++++++++++++++++++++++++++++++++++++++++
>  include/pci.h            | 13 ++++++
>  2 files changed, 105 insertions(+)
>
> diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
> index 4bb30f5d2b..b2d295435a 100644
> --- a/drivers/pci/pci-uclass.c
> +++ b/drivers/pci/pci-uclass.c
> @@ -7,6 +7,7 @@
>  #include <common.h>
>  #include <dm.h>
>  #include <errno.h>
> +#include <linux/log2.h>
>  #include <pci.h>
>  #include <asm/io.h>
>  #include <dm/device-internal.h>
> @@ -1596,6 +1597,97 @@ int dm_pci_capability_clear_and_set_dword(struct udevice *dev, int cap,
>                                                set, PCI_SIZE_32);
>  }
>
> +/**
> + * dm_pci_get_readrq - get PCI Express read request size
> + * @dev: PCI device to query
> + *
> + * Returns maximum memory read request in bytes
> + *    or appropriate error value.
> + */

Please move the comment block to pci.h

> +int dm_pci_get_readrq(struct udevice *dev)
> +{
> +       u16 ctl;
> +       int ret;
> +
> +       ret = dm_pci_capability_read_word(dev, PCI_CAP_ID_EXP,
> +                                         PCI_EXP_DEVCTL, &ctl);
> +       if (ret)
> +               return ret;
> +
> +       return 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12);
> +}
> +
> +/**
> + * dm_pci_set_readrq - set PCI Express maximum memory read request
> + * @dev: PCI device to query
> + * @rq: maximum memory read count in bytes
> + *    valid values are 128, 256, 512, 1024, 2048, 4096
> + */
> +int dm_pci_set_readrq(struct udevice *dev, int rq)
> +{
> +       u16 val;
> +
> +       if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
> +               return -EINVAL;
> +
> +       val = (ffs(rq) - 8) << 12;
> +
> +       return dm_pci_capability_clear_and_set_word(dev, PCI_CAP_ID_EXP,
> +                                                   PCI_EXP_DEVCTL,
> +                                                   PCI_EXP_DEVCTL_READRQ,
> +                                                   val);
> +}
> +
> +/**
> + * dm_pci_get_mps - get PCI Express maximum payload size
> + * @dev: PCI device to query
> + *
> + * Returns maximum payload size in bytes
> + */
> +int dm_pci_get_mps(struct udevice *dev)
> +{
> +       u16 ctl;
> +       int ret;
> +
> +       ret = dm_pci_capability_read_word(dev, PCI_CAP_ID_EXP,
> +                                         PCI_EXP_DEVCTL, &ctl);
> +       if (ret)
> +               return ret;
> +
> +       return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
> +}
> +
> +/**
> + * dm_pci_set_mps - set PCI Express maximum payload size
> + * @dev: PCI device to query
> + * @mps: maximum payload size in bytes
> + *    valid values are 128, 256, 512, 1024, 2048, 4096
> + */
> +int dm_pci_set_mps(struct udevice *dev, int mps)
> +{
> +       u16 val, cap;
> +       int ret;
> +
> +       if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
> +               return -EINVAL;
> +
> +       ret = dm_pci_capability_read_word(dev, PCI_CAP_ID_EXP,
> +                                         PCI_EXP_DEVCAP, &cap);
> +       if (ret)
> +               return ret;
> +
> +       val = ffs(mps) - 8;
> +       if (val > (cap & PCI_EXP_DEVCAP_PAYLOAD))
> +               return -EINVAL;
> +
> +       val <<= 5;
> +
> +       return dm_pci_capability_clear_and_set_word(dev, PCI_CAP_ID_EXP,
> +                                                   PCI_EXP_DEVCTL,
> +                                                   PCI_EXP_DEVCTL_PAYLOAD,
> +                                                   val);
> +}
> +
>  UCLASS_DRIVER(pci) = {
>         .id             = UCLASS_PCI,
>         .name           = "pci",
> diff --git a/include/pci.h b/include/pci.h
> index d7b6d9f4ff..b48df8a363 100644
> --- a/include/pci.h
> +++ b/include/pci.h
> @@ -414,6 +414,14 @@
>  #define PCI_MAX_PCI_DEVICES    32
>  #define PCI_MAX_PCI_FUNCTIONS  8
>
> +/* PCI Express capability registers */
> +#define PCI_EXP_DEVCAP                 4       /* Device capabilities */
> +#define  PCI_EXP_DEVCAP_PAYLOAD                0x0007  /* Max_Payload_Size */
> +
> +#define PCI_EXP_DEVCTL                 8       /* Device Control */
> +#define  PCI_EXP_DEVCTL_PAYLOAD                0x00e0  /* Max_Payload_Size */
> +#define  PCI_EXP_DEVCTL_READRQ         0x7000  /* Max_Read_Request_Size */
> +
>  #define PCI_FIND_CAP_TTL 0x48
>  #define CAP_START_POS 0x40
>
> @@ -1425,6 +1433,11 @@ int dm_pci_capability_clear_and_set_word(struct udevice *dev, int cap,
>  int dm_pci_capability_clear_and_set_dword(struct udevice *dev, int cap,
>                                           int pos, u32 clear, u32 set);
>
> +int dm_pci_get_readrq(struct udevice *dev);
> +int dm_pci_set_readrq(struct udevice *dev, int rq);
> +int dm_pci_get_mps(struct udevice *dev);
> +int dm_pci_set_mps(struct udevice *dev, int mps);
> +
>  #define dm_pci_virt_to_bus(dev, addr, flags) \
>         dm_pci_phys_to_bus(dev, (virt_to_phys(addr)), (flags))
>  #define dm_pci_bus_to_virt(dev, addr, flags, len, map_flags) \
> --

Please add test cases test/dm/pci.c::dm_test_pci_cap()

Regards,
Bin