iosf_mbi.h

  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 */