xref: /openbmc/linux/drivers/pci/hotplug/rpaphp_pci.c (revision 5b4fc395)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.
4  * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
5  *
6  * All rights reserved.
7  *
8  * Send feedback to <lxie@us.ibm.com>
9  *
10  */
11 #include <linux/of.h>
12 #include <linux/pci.h>
13 #include <linux/string.h>
14 
15 #include <asm/pci-bridge.h>
16 #include <asm/rtas.h>
17 #include <asm/machdep.h>
18 
19 #include "../pci.h"		/* for pci_add_new_bus */
20 #include "rpaphp.h"
21 
22 int rpaphp_get_sensor_state(struct slot *slot, int *state)
23 {
24 	int rc;
25 	int setlevel;
26 
27 	rc = rtas_get_sensor(DR_ENTITY_SENSE, slot->index, state);
28 
29 	if (rc < 0) {
30 		if (rc == -EFAULT || rc == -EEXIST) {
31 			dbg("%s: slot must be power up to get sensor-state\n",
32 			    __func__);
33 
34 			/* some slots have to be powered up
35 			 * before get-sensor will succeed.
36 			 */
37 			rc = rtas_set_power_level(slot->power_domain, POWER_ON,
38 						  &setlevel);
39 			if (rc < 0) {
40 				dbg("%s: power on slot[%s] failed rc=%d.\n",
41 				    __func__, slot->name, rc);
42 			} else {
43 				rc = rtas_get_sensor(DR_ENTITY_SENSE,
44 						     slot->index, state);
45 			}
46 		} else if (rc == -ENODEV)
47 			info("%s: slot is unusable\n", __func__);
48 		else
49 			err("%s failed to get sensor state\n", __func__);
50 	}
51 	return rc;
52 }
53 
54 /**
55  * rpaphp_enable_slot - record slot state, config pci device
56  * @slot: target &slot
57  *
58  * Initialize values in the slot structure to indicate if there is a pci card
59  * plugged into the slot. If the slot is not empty, run the pcibios routine
60  * to get pcibios stuff correctly set up.
61  */
62 int rpaphp_enable_slot(struct slot *slot)
63 {
64 	int rc, level, state;
65 	struct pci_bus *bus;
66 
67 	slot->state = EMPTY;
68 
69 	/* Find out if the power is turned on for the slot */
70 	rc = rtas_get_power_level(slot->power_domain, &level);
71 	if (rc)
72 		return rc;
73 
74 	/* Figure out if there is an adapter in the slot */
75 	rc = rpaphp_get_sensor_state(slot, &state);
76 	if (rc)
77 		return rc;
78 
79 	bus = pci_find_bus_by_node(slot->dn);
80 	if (!bus) {
81 		err("%s: no pci_bus for dn %pOF\n", __func__, slot->dn);
82 		return -EINVAL;
83 	}
84 
85 	slot->bus = bus;
86 	slot->pci_devs = &bus->devices;
87 
88 	/* if there's an adapter in the slot, go add the pci devices */
89 	if (state == PRESENT) {
90 		slot->state = NOT_CONFIGURED;
91 
92 		/* non-empty slot has to have child */
93 		if (!slot->dn->child) {
94 			err("%s: slot[%s]'s device_node doesn't have child for adapter\n",
95 			    __func__, slot->name);
96 			return -EINVAL;
97 		}
98 
99 		if (list_empty(&bus->devices)) {
100 			pseries_eeh_init_edev_recursive(PCI_DN(slot->dn));
101 			pci_hp_add_devices(bus);
102 		}
103 
104 		if (!list_empty(&bus->devices)) {
105 			slot->state = CONFIGURED;
106 		}
107 
108 		if (rpaphp_debug) {
109 			struct pci_dev *dev;
110 			dbg("%s: pci_devs of slot[%pOF]\n", __func__, slot->dn);
111 			list_for_each_entry(dev, &bus->devices, bus_list)
112 				dbg("\t%s\n", pci_name(dev));
113 		}
114 	}
115 
116 	return 0;
117 }
118