1 files changed, 253 insertions, 0 deletions
diff --git a/arch/x86/include/asm/iosf_mbi.h b/arch/x86/include/asm/iosf_mbi.h
new file mode 100644
index 000000000..a1911fea8
--- /dev/null
+++ b/arch/x86/include/asm/iosf_mbi.h
@@ -0,0 +1,253 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Intel OnChip System Fabric MailBox access support
+ */
+
+#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
+
+#define MBI_RD_MASK		0xFEFFFFFF
+#define MBI_WR_MASK		0X01000000
+
+#define MBI_MASK_HI		0xFFFFFF00
+#define MBI_MASK_LO		0x000000FF
+#define MBI_ENABLE		0xF0
+
+/* IOSF SB read/write opcodes */
+#define MBI_MMIO_READ		0x00
+#define MBI_MMIO_WRITE		0x01
+#define MBI_CFG_READ		0x04
+#define MBI_CFG_WRITE		0x05
+#define MBI_CR_READ		0x06
+#define MBI_CR_WRITE		0x07
+#define MBI_REG_READ		0x10
+#define MBI_REG_WRITE		0x11
+#define MBI_ESRAM_READ		0x12
+#define MBI_ESRAM_WRITE		0x13
+
+/* Baytrail available units */
+#define BT_MBI_UNIT_AUNIT	0x00
+#define BT_MBI_UNIT_SMC		0x01
+#define BT_MBI_UNIT_CPU		0x02
+#define BT_MBI_UNIT_BUNIT	0x03
+#define BT_MBI_UNIT_PMC		0x04
+#define BT_MBI_UNIT_GFX		0x06
+#define BT_MBI_UNIT_SMI		0x0C
+#define BT_MBI_UNIT_CCK		0x14
+#define BT_MBI_UNIT_USB		0x43
+#define BT_MBI_UNIT_SATA	0xA3
+#define BT_MBI_UNIT_PCIE	0xA6
+
+/* Quark available units */
+#define QRK_MBI_UNIT_HBA	0x00
+#define QRK_MBI_UNIT_HB		0x03
+#define QRK_MBI_UNIT_RMU	0x04
+#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);
+
+/**
+ * iosf_mbi_read() - MailBox Interface read command
+ * @port:	port indicating subunit being accessed
+ * @opcode:	port specific read or write opcode
+ * @offset:	register address offset
+ * @mdr:	register data to be read
+ *
+ * Locking is handled by spinlock - cannot sleep.
+ * Return: Nonzero on error
+ */
+int iosf_mbi_read(u8 port, u8 opcode, u32 offset, u32 *mdr);
+
+/**
+ * iosf_mbi_write() - MailBox unmasked write command
+ * @port:	port indicating subunit being accessed
+ * @opcode:	port specific read or write opcode
+ * @offset:	register address offset
+ * @mdr:	register data to be written
+ *
+ * Locking is handled by spinlock - cannot sleep.
+ * Return: Nonzero on error
+ */
+int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr);
+
+/**
+ * iosf_mbi_modify() - MailBox masked write command
+ * @port:	port indicating subunit being accessed
+ * @opcode:	port specific read or write opcode
+ * @offset:	register address offset
+ * @mdr:	register data being modified
+ * @mask:	mask indicating bits in mdr to be modified
+ *
+ * Locking is handled by spinlock - cannot sleep.
+ * Return: Nonzero on error
+ */
+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.
+ *
+ * Call this function before sending requests to the P-Unit which may make it
+ * access the PMIC, be it through iosf_mbi* functions or through other means.
+ * This function will block all kernel access to the PMIC I2C bus, so that the
+ * P-Unit can safely access the PMIC over the shared I2C bus.
+ *
+ * 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_block_punit_i2c_access() - Block P-Unit accesses to the PMIC bus
+ *
+ * Call this function to block P-Unit access to the PMIC I2C bus, so that the
+ * kernel can safely access the PMIC over the shared I2C bus.
+ *
+ * This function acquires the P-Unit bus semaphore and notifies
+ * pmic_bus_access_notifier listeners that they may no longer access the
+ * P-Unit in a way which may cause it to access the shared I2C bus.
+ *
+ * Note this function may be called multiple times and the bus will not
+ * be released until iosf_mbi_unblock_punit_i2c_access() has been called the
+ * same amount of times.
+ *
+ * Return: Nonzero on error
+ */
+int iosf_mbi_block_punit_i2c_access(void);
+
+/*
+ * iosf_mbi_unblock_punit_i2c_access() - Release PMIC I2C bus block
+ *
+ * Release i2c access block gotten through iosf_mbi_block_punit_i2c_access().
+ */
+void iosf_mbi_unblock_punit_i2c_access(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_unregister_pmic_bus_access_notifier_unlocked - Unregister PMIC bus
+ *                                                         notifier, unlocked
+ *
+ * Like iosf_mbi_unregister_pmic_bus_access_notifier(), but for use when the
+ * caller has already called iosf_mbi_punit_acquire() itself.
+ *
+ * @nb: notifier_block to unregister
+ */
+int iosf_mbi_unregister_pmic_bus_access_notifier_unlocked(
+	struct notifier_block *nb);
+
+/**
+ * iosf_mbi_assert_punit_acquired - Assert that the P-Unit has been acquired.
+ */
+void iosf_mbi_assert_punit_acquired(void);
+
+#else /* CONFIG_IOSF_MBI is not enabled */
+static inline
+bool iosf_mbi_available(void)
+{
+	return false;
+}
+
+static inline
+int iosf_mbi_read(u8 port, u8 opcode, u32 offset, u32 *mdr)
+{
+	WARN(1, "IOSF_MBI driver not available");
+	return -EPERM;
+}
+
+static inline
+int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr)
+{
+	WARN(1, "IOSF_MBI driver not available");
+	return -EPERM;
+}
+
+static inline
+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_unregister_pmic_bus_access_notifier_unlocked(struct notifier_block *nb)
+{
+	return 0;
+}
+
+static inline
+int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v)
+{
+	return 0;
+}
+
+static inline void iosf_mbi_assert_punit_acquired(void) {}
+
+#endif /* CONFIG_IOSF_MBI */
+
+#endif /* IOSF_MBI_SYMS_H */