xref: /openbmc/linux/drivers/pci/hotplug/pciehp.h (revision be709d48)
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 #define MY_NAME	"pciehp"
29 
30 extern bool pciehp_poll_mode;
31 extern int pciehp_poll_time;
32 extern bool pciehp_debug;
33 
34 #define dbg(format, arg...)						\
35 do {									\
36 	if (pciehp_debug)						\
37 		printk(KERN_DEBUG "%s: " format, MY_NAME, ## arg);	\
38 } while (0)
39 #define err(format, arg...)						\
40 	printk(KERN_ERR "%s: " format, MY_NAME, ## arg)
41 #define info(format, arg...)						\
42 	printk(KERN_INFO "%s: " format, MY_NAME, ## arg)
43 #define warn(format, arg...)						\
44 	printk(KERN_WARNING "%s: " format, MY_NAME, ## arg)
45 
46 #define ctrl_dbg(ctrl, format, arg...)					\
47 	do {								\
48 		if (pciehp_debug)					\
49 			dev_printk(KERN_DEBUG, &ctrl->pcie->device,	\
50 					format, ## arg);		\
51 	} while (0)
52 #define ctrl_err(ctrl, format, arg...)					\
53 	dev_err(&ctrl->pcie->device, format, ## arg)
54 #define ctrl_info(ctrl, format, arg...)					\
55 	dev_info(&ctrl->pcie->device, format, ## arg)
56 #define ctrl_warn(ctrl, format, arg...)					\
57 	dev_warn(&ctrl->pcie->device, format, ## arg)
58 
59 #define SLOT_NAME_SIZE 10
60 
61 /**
62  * struct controller - PCIe hotplug controller
63  * @pcie: pointer to the controller's PCIe port service device
64  * @slot_cap: cached copy of the Slot Capabilities register
65  * @slot_ctrl: cached copy of the Slot Control register
66  * @ctrl_lock: serializes writes to the Slot Control register
67  * @cmd_started: jiffies when the Slot Control register was last written;
68  *	the next write is allowed 1 second later, absent a Command Completed
69  *	interrupt (PCIe r4.0, sec 6.7.3.2)
70  * @cmd_busy: flag set on Slot Control register write, cleared by IRQ handler
71  *	on reception of a Command Completed event
72  * @queue: wait queue to wake up on reception of a Command Completed event,
73  *	used for synchronous writes to the Slot Control register
74  * @pending_events: used by the IRQ handler to save events retrieved from the
75  *	Slot Status register for later consumption by the IRQ thread
76  * @notification_enabled: whether the IRQ was requested successfully
77  * @power_fault_detected: whether a power fault was detected by the hardware
78  *	that has not yet been cleared by the user
79  * @poll_thread: thread to poll for slot events if no IRQ is available,
80  *	enabled with pciehp_poll_mode module parameter
81  * @state: current state machine position
82  * @state_lock: protects reads and writes of @state;
83  *	protects scheduling, execution and cancellation of @button_work
84  * @button_work: work item to turn the slot on or off after 5 seconds
85  *	in response to an Attention Button press
86  * @hotplug_slot: structure registered with the PCI hotplug core
87  * @reset_lock: prevents access to the Data Link Layer Link Active bit in the
88  *	Link Status register and to the Presence Detect State bit in the Slot
89  *	Status register during a slot reset which may cause them to flap
90  * @request_result: result of last user request submitted to the IRQ thread
91  * @requester: wait queue to wake up on completion of user request,
92  *	used for synchronous slot enable/disable request via sysfs
93  *
94  * PCIe hotplug has a 1:1 relationship between controller and slot, hence
95  * unlike other drivers, the two aren't represented by separate structures.
96  */
97 struct controller {
98 	struct pcie_device *pcie;
99 
100 	u32 slot_cap;				/* capabilities and quirks */
101 
102 	u16 slot_ctrl;				/* control register access */
103 	struct mutex ctrl_lock;
104 	unsigned long cmd_started;
105 	unsigned int cmd_busy:1;
106 	wait_queue_head_t queue;
107 
108 	atomic_t pending_events;		/* event handling */
109 	unsigned int notification_enabled:1;
110 	unsigned int power_fault_detected;
111 	struct task_struct *poll_thread;
112 
113 	u8 state;				/* state machine */
114 	struct mutex state_lock;
115 	struct delayed_work button_work;
116 
117 	struct hotplug_slot hotplug_slot;	/* hotplug core interface */
118 	struct rw_semaphore reset_lock;
119 	int request_result;
120 	wait_queue_head_t requester;
121 };
122 
123 /**
124  * DOC: Slot state
125  *
126  * @OFF_STATE: slot is powered off, no subordinate devices are enumerated
127  * @BLINKINGON_STATE: slot will be powered on after the 5 second delay,
128  *	green led is blinking
129  * @BLINKINGOFF_STATE: slot will be powered off after the 5 second delay,
130  *	green led is blinking
131  * @POWERON_STATE: slot is currently powering on
132  * @POWEROFF_STATE: slot is currently powering off
133  * @ON_STATE: slot is powered on, subordinate devices have been enumerated
134  */
135 #define OFF_STATE			0
136 #define BLINKINGON_STATE		1
137 #define BLINKINGOFF_STATE		2
138 #define POWERON_STATE			3
139 #define POWEROFF_STATE			4
140 #define ON_STATE			5
141 
142 /**
143  * DOC: Flags to request an action from the IRQ thread
144  *
145  * These are stored together with events read from the Slot Status register,
146  * hence must be greater than its 16-bit width.
147  *
148  * %DISABLE_SLOT: Disable the slot in response to a user request via sysfs or
149  *	an Attention Button press after the 5 second delay
150  * %RERUN_ISR: Used by the IRQ handler to inform the IRQ thread that the
151  *	hotplug port was inaccessible when the interrupt occurred, requiring
152  *	that the IRQ handler is rerun by the IRQ thread after it has made the
153  *	hotplug port accessible by runtime resuming its parents to D0
154  */
155 #define DISABLE_SLOT		(1 << 16)
156 #define RERUN_ISR		(1 << 17)
157 
158 #define ATTN_BUTTN(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_ABP)
159 #define POWER_CTRL(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_PCP)
160 #define MRL_SENS(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_MRLSP)
161 #define ATTN_LED(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_AIP)
162 #define PWR_LED(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_PIP)
163 #define HP_SUPR_RM(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_HPS)
164 #define EMI(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_EIP)
165 #define NO_CMD_CMPL(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_NCCS)
166 #define PSN(ctrl)		(((ctrl)->slot_cap & PCI_EXP_SLTCAP_PSN) >> 19)
167 
168 void pciehp_request(struct controller *ctrl, int action);
169 void pciehp_handle_button_press(struct controller *ctrl);
170 void pciehp_handle_disable_request(struct controller *ctrl);
171 void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events);
172 int pciehp_configure_device(struct controller *ctrl);
173 void pciehp_unconfigure_device(struct controller *ctrl, bool presence);
174 void pciehp_queue_pushbutton_work(struct work_struct *work);
175 struct controller *pcie_init(struct pcie_device *dev);
176 int pcie_init_notification(struct controller *ctrl);
177 void pcie_shutdown_notification(struct controller *ctrl);
178 void pcie_clear_hotplug_events(struct controller *ctrl);
179 void pcie_enable_interrupt(struct controller *ctrl);
180 void pcie_disable_interrupt(struct controller *ctrl);
181 int pciehp_power_on_slot(struct controller *ctrl);
182 void pciehp_power_off_slot(struct controller *ctrl);
183 void pciehp_get_power_status(struct controller *ctrl, u8 *status);
184 
185 void pciehp_set_attention_status(struct controller *ctrl, u8 status);
186 void pciehp_get_latch_status(struct controller *ctrl, u8 *status);
187 int pciehp_query_power_fault(struct controller *ctrl);
188 void pciehp_green_led_on(struct controller *ctrl);
189 void pciehp_green_led_off(struct controller *ctrl);
190 void pciehp_green_led_blink(struct controller *ctrl);
191 bool pciehp_card_present(struct controller *ctrl);
192 bool pciehp_card_present_or_link_active(struct controller *ctrl);
193 int pciehp_check_link_status(struct controller *ctrl);
194 bool pciehp_check_link_active(struct controller *ctrl);
195 void pciehp_release_ctrl(struct controller *ctrl);
196 
197 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot);
198 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot);
199 int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, int probe);
200 int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status);
201 int pciehp_set_raw_indicator_status(struct hotplug_slot *h_slot, u8 status);
202 int pciehp_get_raw_indicator_status(struct hotplug_slot *h_slot, u8 *status);
203 
204 static inline const char *slot_name(struct controller *ctrl)
205 {
206 	return hotplug_slot_name(&ctrl->hotplug_slot);
207 }
208 
209 static inline struct controller *to_ctrl(struct hotplug_slot *hotplug_slot)
210 {
211 	return container_of(hotplug_slot, struct controller, hotplug_slot);
212 }
213 
214 #endif				/* _PCIEHP_H */
215