diff options
Diffstat (limited to 'arch/x86/include/asm/iosf_mbi.h')
| -rw-r--r-- | arch/x86/include/asm/iosf_mbi.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/x86/include/asm/iosf_mbi.h b/arch/x86/include/asm/iosf_mbi.h index b41ee164930a..c313cac36f56 100644 --- a/arch/x86/include/asm/iosf_mbi.h +++ b/arch/x86/include/asm/iosf_mbi.h @@ -5,6 +5,8 @@ #ifndef IOSF_MBI_SYMS_H #define IOSF_MBI_SYMS_H +#include <linux/notifier.h> + #define MBI_MCR_OFFSET 0xD0 #define MBI_MDR_OFFSET 0xD4 #define MBI_MCRX_OFFSET 0xD8 @@ -47,6 +49,10 @@ #define QRK_MBI_UNIT_MM 0x05 #define QRK_MBI_UNIT_SOC 0x31 +/* Action values for the pmic_bus_access_notifier functions */ +#define MBI_PMIC_BUS_ACCESS_BEGIN 1 +#define MBI_PMIC_BUS_ACCESS_END 2 + #if IS_ENABLED(CONFIG_IOSF_MBI) bool iosf_mbi_available(void); @@ -88,6 +94,65 @@ int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr); */ int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask); +/** + * iosf_mbi_punit_acquire() - Acquire access to the P-Unit + * + * One some systems the P-Unit accesses the PMIC to change various voltages + * through the same bus as other kernel drivers use for e.g. battery monitoring. + * + * If a driver sends requests to the P-Unit which require the P-Unit to access + * the PMIC bus while another driver is also accessing the PMIC bus various bad + * things happen. + * + * To avoid these problems this function must be called before accessing the + * P-Unit or the PMIC, be it through iosf_mbi* functions or through other means. + * + * Note on these systems the i2c-bus driver will request a sempahore from the + * P-Unit for exclusive access to the PMIC bus when i2c drivers are accessing + * it, but this does not appear to be sufficient, we still need to avoid making + * certain P-Unit requests during the access window to avoid problems. + * + * This function locks a mutex, as such it may sleep. + */ +void iosf_mbi_punit_acquire(void); + +/** + * iosf_mbi_punit_release() - Release access to the P-Unit + */ +void iosf_mbi_punit_release(void); + +/** + * iosf_mbi_register_pmic_bus_access_notifier - Register PMIC bus notifier + * + * This function can be used by drivers which may need to acquire P-Unit + * managed resources from interrupt context, where iosf_mbi_punit_acquire() + * can not be used. + * + * This function allows a driver to register a notifier to get notified (in a + * process context) before other drivers start accessing the PMIC bus. + * + * This allows the driver to acquire any resources, which it may need during + * the window the other driver is accessing the PMIC, before hand. + * + * @nb: notifier_block to register + */ +int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb); + +/** + * iosf_mbi_register_pmic_bus_access_notifier - Unregister PMIC bus notifier + * + * @nb: notifier_block to unregister + */ +int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb); + +/** + * iosf_mbi_call_pmic_bus_access_notifier_chain - Call PMIC bus notifier chain + * + * @val: action to pass into listener's notifier_call function + * @v: data pointer to pass into listener's notifier_call function + */ +int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v); + #else /* CONFIG_IOSF_MBI is not enabled */ static inline bool iosf_mbi_available(void) @@ -115,6 +180,28 @@ int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask) WARN(1, "IOSF_MBI driver not available"); return -EPERM; } + +static inline void iosf_mbi_punit_acquire(void) {} +static inline void iosf_mbi_punit_release(void) {} + +static inline +int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb) +{ + return 0; +} + +static inline +int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb) +{ + return 0; +} + +static inline +int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v) +{ + return 0; +} + #endif /* CONFIG_IOSF_MBI */ #endif /* IOSF_MBI_SYMS_H */ |