xref: /openbmc/linux/arch/x86/include/asm/iosf_mbi.h (revision 5f55dd54)
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 
60 bool 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  */
72 int 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  */
84 int 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  */
97 int 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 sempahore 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  */
121 void iosf_mbi_punit_acquire(void);
122 
123 /**
124  * iosf_mbi_punit_release() - Release access to the P-Unit
125  */
126 void 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  */
144 int 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  */
151 void 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  */
168 int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb);
169 
170 /**
171  * iosf_mbi_register_pmic_bus_access_notifier - Unregister PMIC bus notifier
172  *
173  * @nb: notifier_block to unregister
174  */
175 int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb);
176 
177 /**
178  * iosf_mbi_unregister_pmic_bus_access_notifier_unlocked - Unregister PMIC bus
179  *                                                         notifier, unlocked
180  *
181  * Like iosf_mbi_unregister_pmic_bus_access_notifier(), but for use when the
182  * caller has already called iosf_mbi_punit_acquire() itself.
183  *
184  * @nb: notifier_block to unregister
185  */
186 int iosf_mbi_unregister_pmic_bus_access_notifier_unlocked(
187 	struct notifier_block *nb);
188 
189 /**
190  * iosf_mbi_assert_punit_acquired - Assert that the P-Unit has been acquired.
191  */
192 void iosf_mbi_assert_punit_acquired(void);
193 
194 #else /* CONFIG_IOSF_MBI is not enabled */
195 static inline
iosf_mbi_available(void)196 bool iosf_mbi_available(void)
197 {
198 	return false;
199 }
200 
201 static inline
iosf_mbi_read(u8 port,u8 opcode,u32 offset,u32 * mdr)202 int iosf_mbi_read(u8 port, u8 opcode, u32 offset, u32 *mdr)
203 {
204 	WARN(1, "IOSF_MBI driver not available");
205 	return -EPERM;
206 }
207 
208 static inline
iosf_mbi_write(u8 port,u8 opcode,u32 offset,u32 mdr)209 int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr)
210 {
211 	WARN(1, "IOSF_MBI driver not available");
212 	return -EPERM;
213 }
214 
215 static inline
iosf_mbi_modify(u8 port,u8 opcode,u32 offset,u32 mdr,u32 mask)216 int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask)
217 {
218 	WARN(1, "IOSF_MBI driver not available");
219 	return -EPERM;
220 }
221 
iosf_mbi_punit_acquire(void)222 static inline void iosf_mbi_punit_acquire(void) {}
iosf_mbi_punit_release(void)223 static inline void iosf_mbi_punit_release(void) {}
224 
225 static inline
iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block * nb)226 int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb)
227 {
228 	return 0;
229 }
230 
231 static inline
iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block * nb)232 int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb)
233 {
234 	return 0;
235 }
236 
237 static inline int
iosf_mbi_unregister_pmic_bus_access_notifier_unlocked(struct notifier_block * nb)238 iosf_mbi_unregister_pmic_bus_access_notifier_unlocked(struct notifier_block *nb)
239 {
240 	return 0;
241 }
242 
243 static inline
iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val,void * v)244 int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v)
245 {
246 	return 0;
247 }
248 
iosf_mbi_assert_punit_acquired(void)249 static inline void iosf_mbi_assert_punit_acquired(void) {}
250 
251 #endif /* CONFIG_IOSF_MBI */
252 
253 #endif /* IOSF_MBI_SYMS_H */
254