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>

1 files changed, 37 insertions, 0 deletions

diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index fc5d001983b3..7a7e66250dfd 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -460,6 +460,41 @@ static void mei_me_pg_exit(struct mei_device *dev)
 }
 
 /**
+ * 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
  *
  * @irq: The irq number
@@ -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,