PCI: pciehp: Add pciehp_set_indicators() to set both indicators

Add pciehp_set_indicators() to set power and attention indicators with a
single register write.

This is a minor optimization because we frequently set both indicators and
this can do it with a single command.  It also reduces the number of
interfaces related to the indicators and makes them more discoverable
because callers use the PCI_EXP_SLTCTL_ATTN_IND_* and
PCI_EXP_SLTCTL_PWR_IND_* definitions directly.

[bhelgaas: extend commit log, s/PCI_EXP_SLTCTL_.*_IND_NONE/INDICATOR_NOOP/
so they don't look like things defined by the spec, add function doc, mask
commands to make it obvious we only send valid commands
(pcie_do_write_cmd() does mask it, but requires more effort to verify)]
Link: https://lore.kernel.org/r/20190903111021.1559-2-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 8c51a04b8083e1d1d7a4894b90a95b8231214199..2ca0f35a6a234a3f5d0c347f50d1ba35ec52d9ac 100644 (file)
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -167,6 +167,9 @@ 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);
 
+#define INDICATOR_NOOP -1      /* Leave indicator unchanged */
+void pciehp_set_indicators(struct controller *ctrl, int pwr, int 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 bd990e3371e31afa9ba130134c7741c765931b26..d7ebcd7111cb73756b390d6927b2d37f9e2d4fab 100644 (file)
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -443,6 +443,42 @@ void pciehp_set_attention_status(struct controller *ctrl, u8 value)
                 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
 }
 
+/**
+ * pciehp_set_indicators() - set attention indicator, power indicator, or both
+ * @ctrl: PCIe hotplug controller
+ * @pwr: one of:
+ *     PCI_EXP_SLTCTL_PWR_IND_ON
+ *     PCI_EXP_SLTCTL_PWR_IND_BLINK
+ *     PCI_EXP_SLTCTL_PWR_IND_OFF
+ * @attn: one of:
+ *     PCI_EXP_SLTCTL_ATTN_IND_ON
+ *     PCI_EXP_SLTCTL_ATTN_IND_BLINK
+ *     PCI_EXP_SLTCTL_ATTN_IND_OFF
+ *
+ * Either @pwr or @attn can also be INDICATOR_NOOP to leave that indicator
+ * unchanged.
+ */
+void pciehp_set_indicators(struct controller *ctrl, int pwr, int attn)
+{
+       u16 cmd = 0, mask = 0;
+
+       if (PWR_LED(ctrl) && pwr != INDICATOR_NOOP) {
+               cmd |= (pwr & PCI_EXP_SLTCTL_PIC);
+               mask |= PCI_EXP_SLTCTL_PIC;
+       }
+
+       if (ATTN_LED(ctrl) && attn != INDICATOR_NOOP) {
+               cmd |= (attn & PCI_EXP_SLTCTL_AIC);
+               mask |= PCI_EXP_SLTCTL_AIC;
+       }
+
+       if (cmd) {
+               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))