bus: mhi: core: Add support for PM state transitions

This commit adds support for transitioning the MHI states as a
part of the power management operations. Helpers functions are
provided for the state transitions, which will be consumed by the
actual power management routines.

This is based on the patch submitted by Sujeev Dias:
https://lkml.org/lkml/2018/7/9/989

Signed-off-by: Sujeev Dias <sdias@codeaurora.org>
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
[jhugo: removed dma_zalloc_coherent() and fixed several bugs]
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
[mani: splitted the pm patch and cleaned up for upstream]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Tested-by: Jeffrey Hugo <jhugo@codeaurora.org>
Link: https://lore.kernel.org/r/20200220095854.4804-7-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 52 insertions, 0 deletions

diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 099d1643b072..fc0cd4af646c 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -106,6 +106,31 @@ enum mhi_ee_type {
 };
 
 /**
+ * enum mhi_state - MHI states
+ * @MHI_STATE_RESET: Reset state
+ * @MHI_STATE_READY: Ready state
+ * @MHI_STATE_M0: M0 state
+ * @MHI_STATE_M1: M1 state
+ * @MHI_STATE_M2: M2 state
+ * @MHI_STATE_M3: M3 state
+ * @MHI_STATE_M3_FAST: M3 Fast state
+ * @MHI_STATE_BHI: BHI state
+ * @MHI_STATE_SYS_ERR: System Error state
+ */
+enum mhi_state {
+	MHI_STATE_RESET = 0x0,
+	MHI_STATE_READY = 0x1,
+	MHI_STATE_M0 = 0x2,
+	MHI_STATE_M1 = 0x3,
+	MHI_STATE_M2 = 0x4,
+	MHI_STATE_M3 = 0x5,
+	MHI_STATE_M3_FAST = 0x6,
+	MHI_STATE_BHI = 0x7,
+	MHI_STATE_SYS_ERR = 0xFF,
+	MHI_STATE_MAX,
+};
+
+/**
  * enum mhi_ch_ee_mask - Execution environment mask for channel
  * @MHI_CH_EE_PBL: Allow channel to be used in PBL EE
  * @MHI_CH_EE_SBL: Allow channel to be used in SBL EE
@@ -266,6 +291,7 @@ struct mhi_controller_config {
  * @pm_state: MHI power management state
  * @db_access: DB access states
  * @ee: MHI device execution environment
+ * @dev_state: MHI device state
  * @dev_wake: Device wakeup count
  * @pending_pkts: Pending packets for the controller
  * @transition_list: List of MHI state transitions
@@ -298,6 +324,7 @@ struct mhi_controller {
 	void __iomem *regs;
 	void __iomem *bhi;
 	void __iomem *wake_db;
+
 	dma_addr_t iova_start;
 	dma_addr_t iova_stop;
 	const char *fw_image;
@@ -324,6 +351,7 @@ struct mhi_controller {
 	u32 pm_state;
 	u32 db_access;
 	enum mhi_ee_type ee;
+	enum mhi_state dev_state;
 	atomic_t dev_wake;
 	atomic_t pending_pkts;
 	struct list_head transition_list;
@@ -392,6 +420,22 @@ struct mhi_result {
 };
 
 /**
+ * struct mhi_buf - MHI Buffer description
+ * @buf: Virtual address of the buffer
+ * @name: Buffer label. For offload channel, configurations name must be:
+ *        ECA - Event context array data
+ *        CCA - Channel context array data
+ * @dma_addr: IOMMU address of the buffer
+ * @len: # of bytes
+ */
+struct mhi_buf {
+	void *buf;
+	const char *name;
+	dma_addr_t dma_addr;
+	size_t len;
+};
+
+/**
  * struct mhi_driver - Structure representing a MHI client driver
  * @probe: CB function for client driver probe function
  * @remove: CB function for client driver remove function
@@ -442,4 +486,12 @@ int mhi_driver_register(struct mhi_driver *mhi_drv);
  */
 void mhi_driver_unregister(struct mhi_driver *mhi_drv);
 
+/**
+ * mhi_set_mhi_state - Set MHI device state
+ * @mhi_cntrl: MHI controller
+ * @state: State to set
+ */
+void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl,
+		       enum mhi_state state);
+
 #endif /* _MHI_H_ */