mei: condition PGI support on HW and HBM version

Enable power gating isolation only if hw and fw support it.
This is indicated by ME_PGIC_HRA bit in ME_CSR_HA register
and on HBM protocol version.

The information is exported to MEI layer through
new pg_is_enabled hw op.
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/hw-me.c

@@ -459,6 +459,41 @@ static void mei_me_pg_exit(struct mei_device *dev)
 	mei_me_reg_write(hw, H_HPG_CSR, reg);
 }
 
+/**
+ * mei_me_pg_is_enabled - detect if PG is supported by HW
+ *
+ * @dev: the device structure
+ *
+ * returns: true is pg supported, false otherwise
+ */
+static bool mei_me_pg_is_enabled(struct mei_device *dev)
+{
+	struct mei_me_hw *hw = to_me_hw(dev);
+	u32 reg = mei_me_reg_read(hw, ME_CSR_HA);
+
+	if ((reg & ME_PGIC_HRA) == 0)
+		goto notsupported;
+
+	if (dev->version.major_version < HBM_MAJOR_VERSION_PGI)
+		goto notsupported;
+
+	if (dev->version.major_version == HBM_MAJOR_VERSION_PGI &&
+	    dev->version.minor_version < HBM_MINOR_VERSION_PGI)
+		goto notsupported;
+
+	return true;
+
+notsupported:
+	dev_dbg(&dev->pdev->dev, "pg: not supported: HGP = %d hbm version %d.%d ?= %d.%d\n",
+		!!(reg & ME_PGIC_HRA),
+		dev->version.major_version,
+		dev->version.minor_version,
+		HBM_MAJOR_VERSION_PGI,
+		HBM_MINOR_VERSION_PGI);
+
+	return false;
+}
+
 /**
  * mei_me_irq_quick_handler - The ISR of the MEI device
  *
@@ -573,6 +608,8 @@ static const struct mei_hw_ops mei_me_hw_ops = {
 	.hw_config = mei_me_hw_config,
 	.hw_start = mei_me_hw_start,
 
+	.pg_is_enabled = mei_me_pg_is_enabled,
+
 	.intr_clear = mei_me_intr_clear,
 	.intr_enable = mei_me_intr_enable,
 	.intr_disable = mei_me_intr_disable,

drivers/misc/mei/hw-txe.c

@@ -279,6 +279,18 @@ int mei_txe_aliveness_set_sync(struct mei_device *dev, u32 req)
 	return 0;
 }
 
+/**
+ * mei_txe_pg_is_enabled - detect if PG is supported by HW
+ *
+ * @dev: the device structure
+ *
+ * returns: true is pg supported, false otherwise
+ */
+static bool mei_txe_pg_is_enabled(struct mei_device *dev)
+{
+	return true;
+}
+
 /**
  * mei_txe_input_ready_interrupt_enable - sets the Input Ready Interrupt
  *
@@ -1017,6 +1029,8 @@ static const struct mei_hw_ops mei_txe_hw_ops = {
 	.hw_config = mei_txe_hw_config,
 	.hw_start = mei_txe_hw_start,
 
+	.pg_is_enabled = mei_txe_pg_is_enabled,
+
 	.intr_clear = mei_txe_intr_clear,
 	.intr_enable = mei_txe_intr_enable,
 	.intr_disable = mei_txe_intr_disable,

drivers/misc/mei/hw.h

@@ -39,6 +39,12 @@
 #define HBM_MINOR_VERSION                   0
 #define HBM_MAJOR_VERSION                   1
 
+/*
+ * MEI version with PGI support
+ */
+#define HBM_MINOR_VERSION_PGI               1
+#define HBM_MAJOR_VERSION_PGI               1
+
 /* Host bus message command opcode */
 #define MEI_HBM_CMD_OP_MSK                  0x7f
 /* Host bus message command RESPONSE */

drivers/misc/mei/mei_dev.h

@@ -220,6 +220,8 @@ struct mei_cl {
  * @hw_start         - start hw after reset
  * @hw_config        - configure hw
 
+ * @pg_is_enabled    - is power gating enabled
+
  * @intr_clear       - clear pending interrupts
  * @intr_enable      - enable interrupts
  * @intr_disable     - disable interrupts
@@ -244,6 +246,8 @@ struct mei_hw_ops {
 	int (*hw_start)(struct mei_device *dev);
 	void (*hw_config)(struct mei_device *dev);
 
+	bool (*pg_is_enabled)(struct mei_device *dev);
+
 	void (*intr_clear)(struct mei_device *dev);
 	void (*intr_enable)(struct mei_device *dev);
 	void (*intr_disable)(struct mei_device *dev);
@@ -558,6 +562,12 @@ static inline void mei_hw_config(struct mei_device *dev)
 {
 	dev->ops->hw_config(dev);
 }
+
+static inline bool mei_pg_is_enabled(struct mei_device *dev)
+{
+	return dev->ops->pg_is_enabled(dev);
+}
+
 static inline int mei_hw_reset(struct mei_device *dev, bool enable)
 {
 	return dev->ops->hw_reset(dev, enable);