[RFC 5/5] ipmi:bt-bmc: Add Microwatt

Joel Stanley joel at jms.id.au
Wed Oct 6 13:35:46 AEDT 2021


Hi Anton,

On Wed, 6 Oct 2021 at 02:12, Anton Blanchard <anton at ozlabs.org> wrote:
>
> This adds the Microwatt specific bits, including interrupt support.

The series looks good.

I've got a couple of patches on the ipmi list that this will conflict with:

 https://sourceforge.net/p/openipmi/mailman/message/37345391/
 https://lore.kernel.org/all/20210903015314.177987-1-joel@jms.id.au/

If there's no feedback from others I suggest basing your series on top
of those, and sending them to Corey on the ipmi list to merge.

Cheers,

Joel

>
> Signed-off-by: Anton Blanchard <anton at ozlabs.org>
> ---
>  .../devicetree/bindings/ipmi/ibt-bmc.txt      |  1 +
>  drivers/char/ipmi/Kconfig                     |  8 ++-
>  drivers/char/ipmi/bt-bmc.c                    | 69 +++++++++++++++++++
>  3 files changed, 75 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt b/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt
> index 78ee716a950e..1b661daf0193 100644
> --- a/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt
> +++ b/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt
> @@ -9,6 +9,7 @@ Required properties:
>  - compatible : should be one of
>         "aspeed,ast2400-ibt-bmc"
>         "aspeed,ast2500-ibt-bmc"
> +       "ibm,microwatt-ibt-bmc"
>  - reg: physical address and size of the registers
>
>  Optional properties:
> diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
> index 8b2f0f675e5f..079302f4eef2 100644
> --- a/drivers/char/ipmi/Kconfig
> +++ b/drivers/char/ipmi/Kconfig
> @@ -152,13 +152,15 @@ config IPMI_KCS_BMC_SERIO
>           called kcs_bmc_serio.
>
>  config BT_IPMI_BMC
> -       depends on ARCH_ASPEED || COMPILE_TEST
> +       depends on ARCH_ASPEED || PPC_MICROWATT || COMPILE_TEST
>         depends on REGMAP && REGMAP_MMIO && MFD_SYSCON
>         tristate "BT IPMI bmc driver"
>         help
>           Provides a driver for the BT (Block Transfer) IPMI interface
> -         found on Aspeed SOCs (AST2400 and AST2500). The driver
> -         implements the BMC side of the BT interface.
> +         found on Aspeed SOCs (AST2400 and AST2500) as well as the OpenPOWER
> +         LPC peripheral macro at
> +         <https://github.com/OpenPOWERFoundation/lpcperipheral>
> +         The driver implements the BMC side of the BT interface.
>
>  config IPMB_DEVICE_INTERFACE
>         tristate 'IPMB Interface handler'
> diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c
> index b48e04405ac4..24327b57c60b 100644
> --- a/drivers/char/ipmi/bt-bmc.c
> +++ b/drivers/char/ipmi/bt-bmc.c
> @@ -41,6 +41,11 @@
>  #define   BT_CR2_IRQ_HBUSY     0x40
>  #define ASPEED_BT_CR3  0xc
>
> +#define MICROWATT_IRQ_MASK     0x0
> +#define MICROWATT_IRQ_STATUS   0x4
> +#define   IRQ_HOST_TO_BMC_ATTN 0x1
> +#define   IRQ_HOST_NOT_BUSY    0x2
> +
>  #define BT_CTRL                0x10
>  #define   BT_CTRL_B_BUSY               0x80
>  #define   BT_CTRL_H_BUSY               0x40
> @@ -395,6 +400,27 @@ static irqreturn_t aspeed_bt_bmc_irq(int irq, void *arg)
>         return IRQ_HANDLED;
>  }
>
> +static irqreturn_t microwatt_bt_bmc_irq(int irq, void *arg)
> +{
> +       struct bt_bmc *bt_bmc = arg;
> +       u32 reg;
> +       int rc;
> +
> +       rc = regmap_read(bt_bmc->map, bt_bmc->offset + MICROWATT_IRQ_STATUS, &reg);
> +       if (rc)
> +               return IRQ_NONE;
> +
> +       /* Interrupt wasn't something we knew about */
> +       if (!(reg & (IRQ_HOST_TO_BMC_ATTN | IRQ_HOST_NOT_BUSY)))
> +               return IRQ_NONE;
> +
> +       /* ack all pending IRQs */
> +       regmap_write(bt_bmc->map, bt_bmc->offset + MICROWATT_IRQ_STATUS, 0);
> +
> +       wake_up(&bt_bmc->queue);
> +       return IRQ_HANDLED;
> +}
> +
>  static int aspeed_bt_bmc_config_irq(struct bt_bmc *bt_bmc,
>                              struct platform_device *pdev)
>  {
> @@ -446,6 +472,48 @@ static const struct bt_bmc_ops aspeed_bt_bmc_ops = {
>         .enable_bt = aspeed_enable_bt,
>  };
>
> +static int microwatt_bt_bmc_config_irq(struct bt_bmc *bt_bmc,
> +                            struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       int rc;
> +
> +       bt_bmc->irq = platform_get_irq_optional(pdev, 0);
> +       if (bt_bmc->irq < 0)
> +               return bt_bmc->irq;
> +
> +       rc = devm_request_irq(dev, bt_bmc->irq, microwatt_bt_bmc_irq, IRQF_SHARED,
> +                             DEVICE_NAME, bt_bmc);
> +       if (rc < 0) {
> +               dev_warn(dev, "Unable to request IRQ %d\n", bt_bmc->irq);
> +               bt_bmc->irq = rc;
> +               return rc;
> +       }
> +
> +       /*
> +        * Configure the hardware to give us an interrupt whenever the H2B
> +        * bit is set or the HBUSY bit is cleared.
> +        *
> +        * H2B will be asserted when the bmc has data for us; HBUSY
> +        * will be cleared (along with B2H) when we can write the next
> +        * message to the BT buffer
> +        */
> +       rc = regmap_update_bits(bt_bmc->map, bt_bmc->offset + MICROWATT_IRQ_MASK,
> +                               (IRQ_HOST_TO_BMC_ATTN | IRQ_HOST_NOT_BUSY),
> +                               (IRQ_HOST_TO_BMC_ATTN | IRQ_HOST_NOT_BUSY));
> +
> +       return rc;
> +}
> +
> +static void microwatt_enable_bt(struct bt_bmc *bt_bmc)
> +{
> +}
> +
> +static const struct bt_bmc_ops microwatt_bt_bmc_ops = {
> +       .config_irq = microwatt_bt_bmc_config_irq,
> +       .enable_bt = microwatt_enable_bt,
> +};
> +
>  static int bt_bmc_probe(struct platform_device *pdev)
>  {
>         struct bt_bmc *bt_bmc;
> @@ -530,6 +598,7 @@ static int bt_bmc_remove(struct platform_device *pdev)
>  static const struct of_device_id bt_bmc_match[] = {
>         { .compatible = "aspeed,ast2400-ibt-bmc", .data = &aspeed_bt_bmc_ops },
>         { .compatible = "aspeed,ast2500-ibt-bmc", .data = &aspeed_bt_bmc_ops },
> +       { .compatible = "ibm,microwatt-ibt-bmc", .data = &microwatt_bt_bmc_ops },
>         { },
>  };
>
> --
> 2.31.1
>


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