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

Denis Efremov
2019-08-11T20:00:23Z

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;
+ }
+
+ 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;
+ }
+
+ 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 */
--
2.21.0