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-rw-r--r--arch/x86/include/asm/iosf_mbi.h56
-rw-r--r--arch/x86/platform/intel/iosf_mbi.c36
2 files changed, 92 insertions, 0 deletions
diff --git a/arch/x86/include/asm/iosf_mbi.h b/arch/x86/include/asm/iosf_mbi.h
index f6119d0e8cba..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);
@@ -115,6 +121,38 @@ void iosf_mbi_punit_acquire(void);
*/
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)
@@ -146,6 +184,24 @@ int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask)
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 */
diff --git a/arch/x86/platform/intel/iosf_mbi.c b/arch/x86/platform/intel/iosf_mbi.c
index ed24fa9fb65d..a952ac199741 100644
--- a/arch/x86/platform/intel/iosf_mbi.c
+++ b/arch/x86/platform/intel/iosf_mbi.c
@@ -35,6 +35,7 @@
static struct pci_dev *mbi_pdev;
static DEFINE_SPINLOCK(iosf_mbi_lock);
static DEFINE_MUTEX(iosf_mbi_punit_mutex);
+static BLOCKING_NOTIFIER_HEAD(iosf_mbi_pmic_bus_access_notifier);
static inline u32 iosf_mbi_form_mcr(u8 op, u8 port, u8 offset)
{
@@ -203,6 +204,41 @@ void iosf_mbi_punit_release(void)
}
EXPORT_SYMBOL(iosf_mbi_punit_release);
+int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb)
+{
+ int ret;
+
+ /* Wait for the bus to go inactive before registering */
+ mutex_lock(&iosf_mbi_punit_mutex);
+ ret = blocking_notifier_chain_register(
+ &iosf_mbi_pmic_bus_access_notifier, nb);
+ mutex_unlock(&iosf_mbi_punit_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL(iosf_mbi_register_pmic_bus_access_notifier);
+
+int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb)
+{
+ int ret;
+
+ /* Wait for the bus to go inactive before unregistering */
+ mutex_lock(&iosf_mbi_punit_mutex);
+ ret = blocking_notifier_chain_unregister(
+ &iosf_mbi_pmic_bus_access_notifier, nb);
+ mutex_unlock(&iosf_mbi_punit_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL(iosf_mbi_unregister_pmic_bus_access_notifier);
+
+int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v)
+{
+ return blocking_notifier_call_chain(
+ &iosf_mbi_pmic_bus_access_notifier, val, v);
+}
+EXPORT_SYMBOL(iosf_mbi_call_pmic_bus_access_notifier_chain);
+
#ifdef CONFIG_IOSF_MBI_DEBUG
static u32 dbg_mdr;
static u32 dbg_mcr;