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_USB 0x43
43#define BT_MBI_UNIT_SATA 0xA3
44#define BT_MBI_UNIT_PCIE 0xA6
45
46/* Quark available units */
47#define QRK_MBI_UNIT_HBA 0x00
48#define QRK_MBI_UNIT_HB 0x03
49#define QRK_MBI_UNIT_RMU 0x04
50#define QRK_MBI_UNIT_MM 0x05
51#define QRK_MBI_UNIT_SOC 0x31
52
53/* Action values for the pmic_bus_access_notifier functions */
54#define MBI_PMIC_BUS_ACCESS_BEGIN 1
55#define MBI_PMIC_BUS_ACCESS_END 2
56
57#if IS_ENABLED(CONFIG_IOSF_MBI)
58
59bool iosf_mbi_available(void);
60
61/**
62 * iosf_mbi_read() - MailBox Interface read command
63 * @port: port indicating subunit being accessed
64 * @opcode: port specific read or write opcode
65 * @offset: register address offset
66 * @mdr: register data to be read
67 *
68 * Locking is handled by spinlock - cannot sleep.
69 * Return: Nonzero on error
70 */
71int iosf_mbi_read(u8 port, u8 opcode, u32 offset, u32 *mdr);
72
73/**
74 * iosf_mbi_write() - MailBox unmasked write command
75 * @port: port indicating subunit being accessed
76 * @opcode: port specific read or write opcode
77 * @offset: register address offset
78 * @mdr: register data to be written
79 *
80 * Locking is handled by spinlock - cannot sleep.
81 * Return: Nonzero on error
82 */
83int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr);
84
85/**
86 * iosf_mbi_modify() - MailBox masked write command
87 * @port: port indicating subunit being accessed
88 * @opcode: port specific read or write opcode
89 * @offset: register address offset
90 * @mdr: register data being modified
91 * @mask: mask indicating bits in mdr to be modified
92 *
93 * Locking is handled by spinlock - cannot sleep.
94 * Return: Nonzero on error
95 */
96int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask);
97
98/**
99 * iosf_mbi_punit_acquire() - Acquire access to the P-Unit
100 *
101 * One some systems the P-Unit accesses the PMIC to change various voltages
102 * through the same bus as other kernel drivers use for e.g. battery monitoring.
103 *
104 * If a driver sends requests to the P-Unit which require the P-Unit to access
105 * the PMIC bus while another driver is also accessing the PMIC bus various bad
106 * things happen.
107 *
108 * Call this function before sending requests to the P-Unit which may make it
109 * access the PMIC, be it through iosf_mbi* functions or through other means.
110 * This function will block all kernel access to the PMIC I2C bus, so that the
111 * P-Unit can safely access the PMIC over the shared I2C bus.
112 *
113 * Note on these systems the i2c-bus driver will request a sempahore from the
114 * P-Unit for exclusive access to the PMIC bus when i2c drivers are accessing
115 * it, but this does not appear to be sufficient, we still need to avoid making
116 * certain P-Unit requests during the access window to avoid problems.
117 *
118 * This function locks a mutex, as such it may sleep.
119 */
120void iosf_mbi_punit_acquire(void);
121
122/**
123 * iosf_mbi_punit_release() - Release access to the P-Unit
124 */
125void iosf_mbi_punit_release(void);
126
127/**
128 * iosf_mbi_block_punit_i2c_access() - Block P-Unit accesses to the PMIC bus
129 *
130 * Call this function to block P-Unit access to the PMIC I2C bus, so that the
131 * kernel can safely access the PMIC over the shared I2C bus.
132 *
133 * This function acquires the P-Unit bus semaphore and notifies
134 * pmic_bus_access_notifier listeners that they may no longer access the
135 * P-Unit in a way which may cause it to access the shared I2C bus.
136 *
137 * Note this function may be called multiple times and the bus will not
138 * be released until iosf_mbi_unblock_punit_i2c_access() has been called the
139 * same amount of times.
140 *
141 * Return: Nonzero on error
142 */
143int iosf_mbi_block_punit_i2c_access(void);
144
145/*
146 * iosf_mbi_unblock_punit_i2c_access() - Release PMIC I2C bus block
147 *
148 * Release i2c access block gotten through iosf_mbi_block_punit_i2c_access().
149 */
150void iosf_mbi_unblock_punit_i2c_access(void);
151
152/**
153 * iosf_mbi_register_pmic_bus_access_notifier - Register PMIC bus notifier
154 *
155 * This function can be used by drivers which may need to acquire P-Unit
156 * managed resources from interrupt context, where iosf_mbi_punit_acquire()
157 * can not be used.
158 *
159 * This function allows a driver to register a notifier to get notified (in a
160 * process context) before other drivers start accessing the PMIC bus.
161 *
162 * This allows the driver to acquire any resources, which it may need during
163 * the window the other driver is accessing the PMIC, before hand.
164 *
165 * @nb: notifier_block to register
166 */
167int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb);
168
169/**
170 * iosf_mbi_register_pmic_bus_access_notifier - Unregister PMIC bus notifier
171 *
172 * @nb: notifier_block to unregister
173 */
174int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb);
175
176/**
177 * iosf_mbi_unregister_pmic_bus_access_notifier_unlocked - Unregister PMIC bus
178 * notifier, unlocked
179 *
180 * Like iosf_mbi_unregister_pmic_bus_access_notifier(), but for use when the
181 * caller has already called iosf_mbi_punit_acquire() itself.
182 *
183 * @nb: notifier_block to unregister
184 */
185int iosf_mbi_unregister_pmic_bus_access_notifier_unlocked(
186 struct notifier_block *nb);
187
188/**
189 * iosf_mbi_assert_punit_acquired - Assert that the P-Unit has been acquired.
190 */
191void iosf_mbi_assert_punit_acquired(void);
192
193#else /* CONFIG_IOSF_MBI is not enabled */
194static inline
195bool iosf_mbi_available(void)
196{
197 return false;
198}
199
200static inline
201int iosf_mbi_read(u8 port, u8 opcode, u32 offset, u32 *mdr)
202{
203 WARN(1, "IOSF_MBI driver not available");
204 return -EPERM;
205}
206
207static inline
208int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr)
209{
210 WARN(1, "IOSF_MBI driver not available");
211 return -EPERM;
212}
213
214static inline
215int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask)
216{
217 WARN(1, "IOSF_MBI driver not available");
218 return -EPERM;
219}
220
221static inline void iosf_mbi_punit_acquire(void) {}
222static inline void iosf_mbi_punit_release(void) {}
223
224static inline
225int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb)
226{
227 return 0;
228}
229
230static inline
231int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb)
232{
233 return 0;
234}
235
236static inline int
237iosf_mbi_unregister_pmic_bus_access_notifier_unlocked(struct notifier_block *nb)
238{
239 return 0;
240}
241
242static inline
243int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v)
244{
245 return 0;
246}
247
248static inline void iosf_mbi_assert_punit_acquired(void) {}
249
250#endif /* CONFIG_IOSF_MBI */
251
252#endif /* IOSF_MBI_SYMS_H */
253