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Diffstat (limited to 'arch/x86/include/asm/iosf_mbi.h')
-rw-r--r--arch/x86/include/asm/iosf_mbi.h87
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 */