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
59 bool 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 */
71 int 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 */
83 int 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 */
96 int 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 */
120 void iosf_mbi_punit_acquire(void);
121
122 /**
123 * iosf_mbi_punit_release() - Release access to the P-Unit
124 */
125 void 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 */
143 int 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 */
150 void 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 */
167 int 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 */
174 int 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 */
185 int 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 */
191 void iosf_mbi_assert_punit_acquired(void);
192
193 #else /* CONFIG_IOSF_MBI is not enabled */
194 static inline
195 bool iosf_mbi_available(void)
196 {
197 return false;
198 }
199
200 static inline
201 int 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
207 static inline
208 int 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
214 static inline
215 int 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
221 static inline void iosf_mbi_punit_acquire(void) {}
222 static inline void iosf_mbi_punit_release(void) {}
223
224 static inline
225 int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb)
226 {
227 return 0;
228 }
229
230 static inline
231 int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb)
232 {
233 return 0;
234 }
235
236 static inline int
237 iosf_mbi_unregister_pmic_bus_access_notifier_unlocked(struct notifier_block *nb)
238 {
239 return 0;
240 }
241
242 static inline
243 int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v)
244 {
245 return 0;
246 }
247
248 static inline void iosf_mbi_assert_punit_acquired(void) {}
249
250 #endif /* CONFIG_IOSF_MBI */
251
252 #endif /* IOSF_MBI_SYMS_H */