Re: [PATCH v2 1/4] PCI: pciehp: Add pciehp_set_indicators() to jointly set LED indicators

sathyanarayanan kuppuswamy
2019-08-12T18:28:28Z

Hi,

On 8/11/19 12:59 PM, Denis Efremov wrote:
> Add pciehp_set_indicators() to set power and attention indicators with a
> single register write. Thus, avoiding waiting twice for Command Complete.
> enum pciehp_indicator introduced to switch between the indicators statuses.
>
> Signed-off-by: Denis Efremov <efremov@linux.com>
> ---
> drivers/pci/hotplug/pciehp.h | 14 ++++++++++++
> drivers/pci/hotplug/pciehp_hpc.c | 38 ++++++++++++++++++++++++++++++++
> include/uapi/linux/pci_regs.h | 2 ++
> 3 files changed, 54 insertions(+)
>
> diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
> index 8c51a04b8083..17305a6f01f1 100644
> --- a/drivers/pci/hotplug/pciehp.h
> +++ b/drivers/pci/hotplug/pciehp.h
> @@ -150,6 +150,17 @@ struct controller {
> #define NO_CMD_CMPL(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_NCCS)
> #define PSN(ctrl) (((ctrl)->slot_cap & PCI_EXP_SLTCAP_PSN) >> 19)
>
> +enum pciehp_indicator {
> + ATTN_NONE = -1,
> + ATTN_ON = 1,
> + ATTN_BLINK = 2,
> + ATTN_OFF = 3,
> + PWR_NONE = -1,
> + PWR_ON = 1,
> + PWR_BLINK = 2,
> + PWR_OFF = 3,
> +};
> +
> void pciehp_request(struct controller *ctrl, int action);
> void pciehp_handle_button_press(struct controller *ctrl);
> void pciehp_handle_disable_request(struct controller *ctrl);
> @@ -167,6 +178,9 @@ int pciehp_power_on_slot(struct controller *ctrl);
> void pciehp_power_off_slot(struct controller *ctrl);
> void pciehp_get_power_status(struct controller *ctrl, u8 *status);
>
> +void pciehp_set_indicators(struct controller *ctrl,
> + enum pciehp_indicator pwr,
> + enum pciehp_indicator attn);
> void pciehp_set_attention_status(struct controller *ctrl, u8 status);
> void pciehp_get_latch_status(struct controller *ctrl, u8 *status);
> int pciehp_query_power_fault(struct controller *ctrl);
> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
> index bd990e3371e3..5a690b1579ec 100644
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -443,6 +443,44 @@ void pciehp_set_attention_status(struct controller *ctrl, u8 value)
> pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
> }
>
> +void pciehp_set_indicators(struct controller *ctrl,
> + enum pciehp_indicator pwr,
> + enum pciehp_indicator attn)
> +{
> + u16 cmd = 0, mask = 0;
> +
> + if ((!PWR_LED(ctrl) || pwr == PWR_NONE) &&
> + (!ATTN_LED(ctrl) || attn == ATTN_NONE))
> + return;
> +
> + switch (pwr) {
> + case PWR_ON:
> + case PWR_BLINK:
> + case PWR_OFF:
> + cmd = pwr << PCI_EXP_SLTCTL_PWR_IND_OFFSET;
> + mask = PCI_EXP_SLTCTL_PIC;
> + break;
> + default:
> + break;
> + }
Do we need to switch case here ? if (pwr > 0) {} should work right ?
> +
> + switch (attn) {
> + case ATTN_ON:
> + case ATTN_BLINK:
> + case ATTN_OFF:
> + cmd |= attn << PCI_EXP_SLTCTL_ATTN_IND_OFFSET;
> + mask |= PCI_EXP_SLTCTL_AIC;
> + break;
> + default:
> + break;
> + }
Same here. if (attn > 0) {}
> +
> + pcie_write_cmd_nowait(ctrl, cmd, mask);
> + ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
> + pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
> + cmd);
> +}
> +
> void pciehp_green_led_on(struct controller *ctrl)
> {
> if (!PWR_LED(ctrl))
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index f28e562d7ca8..18722d1f54a0 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -591,10 +591,12 @@
> #define PCI_EXP_SLTCTL_CCIE 0x0010 /* Command Completed Interrupt Enable */
> #define PCI_EXP_SLTCTL_HPIE 0x0020 /* Hot-Plug Interrupt Enable */
> #define PCI_EXP_SLTCTL_AIC 0x00c0 /* Attention Indicator Control */
> +#define PCI_EXP_SLTCTL_ATTN_IND_OFFSET 0x6 /* Attention Indicator Offset */
> #define PCI_EXP_SLTCTL_ATTN_IND_ON 0x0040 /* Attention Indicator on */
> #define PCI_EXP_SLTCTL_ATTN_IND_BLINK 0x0080 /* Attention Indicator blinking */
> #define PCI_EXP_SLTCTL_ATTN_IND_OFF 0x00c0 /* Attention Indicator off */
> #define PCI_EXP_SLTCTL_PIC 0x0300 /* Power Indicator Control */
> +#define PCI_EXP_SLTCTL_PWR_IND_OFFSET 0x8 /* Power Indicator Offset */
> #define PCI_EXP_SLTCTL_PWR_IND_ON 0x0100 /* Power Indicator on */
> #define PCI_EXP_SLTCTL_PWR_IND_BLINK 0x0200 /* Power Indicator blinking */
> #define PCI_EXP_SLTCTL_PWR_IND_OFF 0x0300 /* Power Indicator off */

--
Sathyanarayanan Kuppuswamy
Linux kernel developer