xref: /openbmc/linux/drivers/pci/hotplug/pciehp.h (revision b830f94f)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * PCI Express Hot Plug Controller Driver
4  *
5  * Copyright (C) 1995,2001 Compaq Computer Corporation
6  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
7  * Copyright (C) 2001 IBM Corp.
8  * Copyright (C) 2003-2004 Intel Corporation
9  *
10  * All rights reserved.
11  *
12  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
13  *
14  */
15 #ifndef _PCIEHP_H
16 #define _PCIEHP_H
17 
18 #include <linux/types.h>
19 #include <linux/pci.h>
20 #include <linux/pci_hotplug.h>
21 #include <linux/delay.h>
22 #include <linux/mutex.h>
23 #include <linux/rwsem.h>
24 #include <linux/workqueue.h>
25 
26 #include "../pcie/portdrv.h"
27 
28 extern bool pciehp_poll_mode;
29 extern int pciehp_poll_time;
30 
31 /*
32  * Set CONFIG_DYNAMIC_DEBUG=y and boot with 'dyndbg="file pciehp* +p"' to
33  * enable debug messages.
34  */
35 #define ctrl_dbg(ctrl, format, arg...)					\
36 	pci_dbg(ctrl->pcie->port, format, ## arg)
37 #define ctrl_err(ctrl, format, arg...)					\
38 	pci_err(ctrl->pcie->port, format, ## arg)
39 #define ctrl_info(ctrl, format, arg...)					\
40 	pci_info(ctrl->pcie->port, format, ## arg)
41 #define ctrl_warn(ctrl, format, arg...)					\
42 	pci_warn(ctrl->pcie->port, format, ## arg)
43 
44 #define SLOT_NAME_SIZE 10
45 
46 /**
47  * struct controller - PCIe hotplug controller
48  * @pcie: pointer to the controller's PCIe port service device
49  * @slot_cap: cached copy of the Slot Capabilities register
50  * @slot_ctrl: cached copy of the Slot Control register
51  * @ctrl_lock: serializes writes to the Slot Control register
52  * @cmd_started: jiffies when the Slot Control register was last written;
53  *	the next write is allowed 1 second later, absent a Command Completed
54  *	interrupt (PCIe r4.0, sec 6.7.3.2)
55  * @cmd_busy: flag set on Slot Control register write, cleared by IRQ handler
56  *	on reception of a Command Completed event
57  * @queue: wait queue to wake up on reception of a Command Completed event,
58  *	used for synchronous writes to the Slot Control register
59  * @pending_events: used by the IRQ handler to save events retrieved from the
60  *	Slot Status register for later consumption by the IRQ thread
61  * @notification_enabled: whether the IRQ was requested successfully
62  * @power_fault_detected: whether a power fault was detected by the hardware
63  *	that has not yet been cleared by the user
64  * @poll_thread: thread to poll for slot events if no IRQ is available,
65  *	enabled with pciehp_poll_mode module parameter
66  * @state: current state machine position
67  * @state_lock: protects reads and writes of @state;
68  *	protects scheduling, execution and cancellation of @button_work
69  * @button_work: work item to turn the slot on or off after 5 seconds
70  *	in response to an Attention Button press
71  * @hotplug_slot: structure registered with the PCI hotplug core
72  * @reset_lock: prevents access to the Data Link Layer Link Active bit in the
73  *	Link Status register and to the Presence Detect State bit in the Slot
74  *	Status register during a slot reset which may cause them to flap
75  * @request_result: result of last user request submitted to the IRQ thread
76  * @requester: wait queue to wake up on completion of user request,
77  *	used for synchronous slot enable/disable request via sysfs
78  *
79  * PCIe hotplug has a 1:1 relationship between controller and slot, hence
80  * unlike other drivers, the two aren't represented by separate structures.
81  */
82 struct controller {
83 	struct pcie_device *pcie;
84 
85 	u32 slot_cap;				/* capabilities and quirks */
86 
87 	u16 slot_ctrl;				/* control register access */
88 	struct mutex ctrl_lock;
89 	unsigned long cmd_started;
90 	unsigned int cmd_busy:1;
91 	wait_queue_head_t queue;
92 
93 	atomic_t pending_events;		/* event handling */
94 	unsigned int notification_enabled:1;
95 	unsigned int power_fault_detected;
96 	struct task_struct *poll_thread;
97 
98 	u8 state;				/* state machine */
99 	struct mutex state_lock;
100 	struct delayed_work button_work;
101 
102 	struct hotplug_slot hotplug_slot;	/* hotplug core interface */
103 	struct rw_semaphore reset_lock;
104 	int request_result;
105 	wait_queue_head_t requester;
106 };
107 
108 /**
109  * DOC: Slot state
110  *
111  * @OFF_STATE: slot is powered off, no subordinate devices are enumerated
112  * @BLINKINGON_STATE: slot will be powered on after the 5 second delay,
113  *	green led is blinking
114  * @BLINKINGOFF_STATE: slot will be powered off after the 5 second delay,
115  *	green led is blinking
116  * @POWERON_STATE: slot is currently powering on
117  * @POWEROFF_STATE: slot is currently powering off
118  * @ON_STATE: slot is powered on, subordinate devices have been enumerated
119  */
120 #define OFF_STATE			0
121 #define BLINKINGON_STATE		1
122 #define BLINKINGOFF_STATE		2
123 #define POWERON_STATE			3
124 #define POWEROFF_STATE			4
125 #define ON_STATE			5
126 
127 /**
128  * DOC: Flags to request an action from the IRQ thread
129  *
130  * These are stored together with events read from the Slot Status register,
131  * hence must be greater than its 16-bit width.
132  *
133  * %DISABLE_SLOT: Disable the slot in response to a user request via sysfs or
134  *	an Attention Button press after the 5 second delay
135  * %RERUN_ISR: Used by the IRQ handler to inform the IRQ thread that the
136  *	hotplug port was inaccessible when the interrupt occurred, requiring
137  *	that the IRQ handler is rerun by the IRQ thread after it has made the
138  *	hotplug port accessible by runtime resuming its parents to D0
139  */
140 #define DISABLE_SLOT		(1 << 16)
141 #define RERUN_ISR		(1 << 17)
142 
143 #define ATTN_BUTTN(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_ABP)
144 #define POWER_CTRL(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_PCP)
145 #define MRL_SENS(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_MRLSP)
146 #define ATTN_LED(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_AIP)
147 #define PWR_LED(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_PIP)
148 #define HP_SUPR_RM(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_HPS)
149 #define EMI(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_EIP)
150 #define NO_CMD_CMPL(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_NCCS)
151 #define PSN(ctrl)		(((ctrl)->slot_cap & PCI_EXP_SLTCAP_PSN) >> 19)
152 
153 void pciehp_request(struct controller *ctrl, int action);
154 void pciehp_handle_button_press(struct controller *ctrl);
155 void pciehp_handle_disable_request(struct controller *ctrl);
156 void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events);
157 int pciehp_configure_device(struct controller *ctrl);
158 void pciehp_unconfigure_device(struct controller *ctrl, bool presence);
159 void pciehp_queue_pushbutton_work(struct work_struct *work);
160 struct controller *pcie_init(struct pcie_device *dev);
161 int pcie_init_notification(struct controller *ctrl);
162 void pcie_shutdown_notification(struct controller *ctrl);
163 void pcie_clear_hotplug_events(struct controller *ctrl);
164 void pcie_enable_interrupt(struct controller *ctrl);
165 void pcie_disable_interrupt(struct controller *ctrl);
166 int pciehp_power_on_slot(struct controller *ctrl);
167 void pciehp_power_off_slot(struct controller *ctrl);
168 void pciehp_get_power_status(struct controller *ctrl, u8 *status);
169 
170 void pciehp_set_attention_status(struct controller *ctrl, u8 status);
171 void pciehp_get_latch_status(struct controller *ctrl, u8 *status);
172 int pciehp_query_power_fault(struct controller *ctrl);
173 void pciehp_green_led_on(struct controller *ctrl);
174 void pciehp_green_led_off(struct controller *ctrl);
175 void pciehp_green_led_blink(struct controller *ctrl);
176 bool pciehp_card_present(struct controller *ctrl);
177 bool pciehp_card_present_or_link_active(struct controller *ctrl);
178 int pciehp_check_link_status(struct controller *ctrl);
179 bool pciehp_check_link_active(struct controller *ctrl);
180 void pciehp_release_ctrl(struct controller *ctrl);
181 
182 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot);
183 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot);
184 int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, int probe);
185 int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status);
186 int pciehp_set_raw_indicator_status(struct hotplug_slot *h_slot, u8 status);
187 int pciehp_get_raw_indicator_status(struct hotplug_slot *h_slot, u8 *status);
188 
189 static inline const char *slot_name(struct controller *ctrl)
190 {
191 	return hotplug_slot_name(&ctrl->hotplug_slot);
192 }
193 
194 static inline struct controller *to_ctrl(struct hotplug_slot *hotplug_slot)
195 {
196 	return container_of(hotplug_slot, struct controller, hotplug_slot);
197 }
198 
199 #endif				/* _PCIEHP_H */
200