1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Intel OnChip System Fabric MailBox access support
4 */
5
6#ifndef IOSF_MBI_SYMS_H
7#define IOSF_MBI_SYMS_H
8
9#include <linux/notifier.h>
10
11#define MBI_MCR_OFFSET 0xD0
12#define MBI_MDR_OFFSET 0xD4
13#define MBI_MCRX_OFFSET 0xD8
14
15#define MBI_RD_MASK 0xFEFFFFFF
16#define MBI_WR_MASK 0X01000000
17
18#define MBI_MASK_HI 0xFFFFFF00
19#define MBI_MASK_LO 0x000000FF
20#define MBI_ENABLE 0xF0
21
22/* IOSF SB read/write opcodes */
23#define MBI_MMIO_READ 0x00
24#define MBI_MMIO_WRITE 0x01
25#define MBI_CFG_READ 0x04
26#define MBI_CFG_WRITE 0x05
27#define MBI_CR_READ 0x06
28#define MBI_CR_WRITE 0x07
29#define MBI_REG_READ 0x10
30#define MBI_REG_WRITE 0x11
31#define MBI_ESRAM_READ 0x12
32#define MBI_ESRAM_WRITE 0x13
33
34/* Baytrail available units */
35#define BT_MBI_UNIT_AUNIT 0x00
36#define BT_MBI_UNIT_SMC 0x01
37#define BT_MBI_UNIT_CPU 0x02
38#define BT_MBI_UNIT_BUNIT 0x03
39#define BT_MBI_UNIT_PMC 0x04
40#define BT_MBI_UNIT_GFX 0x06
41#define BT_MBI_UNIT_SMI 0x0C
42#define BT_MBI_UNIT_CCK 0x14
43#define BT_MBI_UNIT_USB 0x43
44#define BT_MBI_UNIT_SATA 0xA3
45#define BT_MBI_UNIT_PCIE 0xA6
46
47/* Quark available units */
48#define QRK_MBI_UNIT_HBA 0x00
49#define QRK_MBI_UNIT_HB 0x03
50#define QRK_MBI_UNIT_RMU 0x04
51#define QRK_MBI_UNIT_MM 0x05
52#define QRK_MBI_UNIT_SOC 0x31
53
54/* Action values for the pmic_bus_access_notifier functions */
55#define MBI_PMIC_BUS_ACCESS_BEGIN 1
56#define MBI_PMIC_BUS_ACCESS_END 2
57
58#if IS_ENABLED(CONFIG_IOSF_MBI)
59
60bool iosf_mbi_available(void);
61
62/**
63 * iosf_mbi_read() - MailBox Interface read command
64 * @port: port indicating subunit being accessed
65 * @opcode: port specific read or write opcode
66 * @offset: register address offset
67 * @mdr: register data to be read
68 *
69 * Locking is handled by spinlock - cannot sleep.
70 * Return: Nonzero on error
71 */
72int iosf_mbi_read(u8 port, u8 opcode, u32 offset, u32 *mdr);
73
74/**
75 * iosf_mbi_write() - MailBox unmasked write command
76 * @port: port indicating subunit being accessed
77 * @opcode: port specific read or write opcode
78 * @offset: register address offset
79 * @mdr: register data to be written
80 *
81 * Locking is handled by spinlock - cannot sleep.
82 * Return: Nonzero on error
83 */
84int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr);
85
86/**
87 * iosf_mbi_modify() - MailBox masked write command
88 * @port: port indicating subunit being accessed
89 * @opcode: port specific read or write opcode
90 * @offset: register address offset
91 * @mdr: register data being modified
92 * @mask: mask indicating bits in mdr to be modified
93 *
94 * Locking is handled by spinlock - cannot sleep.
95 * Return: Nonzero on error
96 */
97int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask);
98
99/**
100 * iosf_mbi_punit_acquire() - Acquire access to the P-Unit
101 *
102 * One some systems the P-Unit accesses the PMIC to change various voltages
103 * through the same bus as other kernel drivers use for e.g. battery monitoring.
104 *
105 * If a driver sends requests to the P-Unit which require the P-Unit to access
106 * the PMIC bus while another driver is also accessing the PMIC bus various bad
107 * things happen.
108 *
109 * Call this function before sending requests to the P-Unit which may make it
110 * access the PMIC, be it through iosf_mbi* functions or through other means.
111 * This function will block all kernel access to the PMIC I2C bus, so that the
112 * P-Unit can safely access the PMIC over the shared I2C bus.
113 *
114 * Note on these systems the i2c-bus driver will request a semaphore from the
115 * P-Unit for exclusive access to the PMIC bus when i2c drivers are accessing
116 * it, but this does not appear to be sufficient, we still need to avoid making
117 * certain P-Unit requests during the access window to avoid problems.
118 *
119 * This function locks a mutex, as such it may sleep.
120 */
121void iosf_mbi_punit_acquire(void);
122
123/**
124 * iosf_mbi_punit_release() - Release access to the P-Unit
125 */
126void iosf_mbi_punit_release(void);
127
128/**
129 * iosf_mbi_block_punit_i2c_access() - Block P-Unit accesses to the PMIC bus
130 *
131 * Call this function to block P-Unit access to the PMIC I2C bus, so that the
132 * kernel can safely access the PMIC over the shared I2C bus.
133 *
134 * This function acquires the P-Unit bus semaphore and notifies
135 * pmic_bus_access_notifier listeners that they may no longer access the
136 * P-Unit in a way which may cause it to access the shared I2C bus.
137 *
138 * Note this function may be called multiple times and the bus will not
139 * be released until iosf_mbi_unblock_punit_i2c_access() has been called the
140 * same amount of times.
141 *
142 * Return: Nonzero on error
143 */
144int iosf_mbi_block_punit_i2c_access(void);
145
146/*
147 * iosf_mbi_unblock_punit_i2c_access() - Release PMIC I2C bus block
148 *
149 * Release i2c access block gotten through iosf_mbi_block_punit_i2c_access().
150 */
151void iosf_mbi_unblock_punit_i2c_access(void);
152
153/**
154 * iosf_mbi_register_pmic_bus_access_notifier - Register PMIC bus notifier
155 *
156 * This function can be used by drivers which may need to acquire P-Unit
157 * managed resources from interrupt context, where iosf_mbi_punit_acquire()
158 * can not be used.
159 *
160 * This function allows a driver to register a notifier to get notified (in a
161 * process context) before other drivers start accessing the PMIC bus.
162 *
163 * This allows the driver to acquire any resources, which it may need during
164 * the window the other driver is accessing the PMIC, before hand.
165 *
166 * @nb: notifier_block to register
167 */
168int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb);
169
170/**
171 * iosf_mbi_unregister_pmic_bus_access_notifier_unlocked - Unregister PMIC bus
172 * notifier, unlocked
173 *
174 * Like iosf_mbi_unregister_pmic_bus_access_notifier(), but for use when the
175 * caller has already called iosf_mbi_punit_acquire() itself.
176 *
177 * @nb: notifier_block to unregister
178 */
179int iosf_mbi_unregister_pmic_bus_access_notifier_unlocked(
180 struct notifier_block *nb);
181
182/**
183 * iosf_mbi_assert_punit_acquired - Assert that the P-Unit has been acquired.
184 */
185void iosf_mbi_assert_punit_acquired(void);
186
187#else /* CONFIG_IOSF_MBI is not enabled */
188static inline
189bool iosf_mbi_available(void)
190{
191 return false;
192}
193
194static inline
195int iosf_mbi_read(u8 port, u8 opcode, u32 offset, u32 *mdr)
196{
197 WARN(1, "IOSF_MBI driver not available");
198 return -EPERM;
199}
200
201static inline
202int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr)
203{
204 WARN(1, "IOSF_MBI driver not available");
205 return -EPERM;
206}
207
208static inline
209int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask)
210{
211 WARN(1, "IOSF_MBI driver not available");
212 return -EPERM;
213}
214
215static inline void iosf_mbi_punit_acquire(void) {}
216static inline void iosf_mbi_punit_release(void) {}
217
218static inline
219int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb)
220{
221 return 0;
222}
223
224static inline
225int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb)
226{
227 return 0;
228}
229
230static inline int
231iosf_mbi_unregister_pmic_bus_access_notifier_unlocked(struct notifier_block *nb)
232{
233 return 0;
234}
235
236static inline
237int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v)
238{
239 return 0;
240}
241
242static inline void iosf_mbi_assert_punit_acquired(void) {}
243
244#endif /* CONFIG_IOSF_MBI */
245
246#endif /* IOSF_MBI_SYMS_H */
247