[PATCH 11/26] drm/i915/slpc: Update sysfs/debugfs interfaces for frequency parameters

[Sagar Arun Kamble]

From: Tom O'Rourke <Tom.O'Rourke at intel.com>

When SLPC is controlling requested frequency, the rps.cur_freq
value is not used to make the frequency request.

Requested frequency from register RPNSWREQ has the value
most recently requested by SLPC firmware. Adding new sysfs
interface gt_req_freq_mhz to know this value.
SLPC requested value needs to be made available to i915 without
reading RPNSWREQ.

v1: Replace HAS_SLPC with intel_slpc_active (Paulo)
    Avoid magic numbers (Nick)
    Use a function for repeated code (Jon)

v2: Add "SLPC Active" to i915_frequency_info output and
    don't update cur_freq as it is driver internal request. (Chris)

v3: Removing sysfs interface gt_req_freq_mhz out of this patch
    for proper division of functionality. (Sagar)

Signed-off-by: Tom O'Rourke <Tom.O'Rourke at intel.com>
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 6 ++++++
 drivers/gpu/drm/i915/i915_sysfs.c   | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 7d7b4d9..d15ad6c 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1106,6 +1106,9 @@ static int i915_frequency_info(struct seq_file *m, void *unused)
 
 	intel_runtime_pm_get(dev_priv);
 
+	if (intel_slpc_active(dev_priv))
+		seq_puts(m, "SLPC Active\n");
+
 	if (IS_GEN5(dev_priv)) {
 		u16 rgvswctl = I915_READ16(MEMSWCTL);
 		u16 rgvstat = I915_READ16(MEMSTAT_ILK);
@@ -2338,6 +2341,9 @@ static int i915_rps_boost_info(struct seq_file *m, void *data)
 	struct drm_device *dev = &dev_priv->drm;
 	struct drm_file *file;
 
+	if (intel_slpc_active(dev_priv))
+		return -ENODEV;
+
 	seq_printf(m, "RPS enabled? %d\n", dev_priv->rps.enabled);
 	seq_printf(m, "GPU busy? %s [%x]\n",
 		   yesno(dev_priv->gt.awake), dev_priv->gt.active_engines);
diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index 2d482f6..cee5f07 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -299,6 +299,9 @@ static ssize_t gt_cur_freq_mhz_show(struct device *kdev,
 {
 	struct drm_i915_private *dev_priv = kdev_minor_to_i915(kdev);
 
+	if (intel_slpc_active(dev_priv))
+		return -ENODEV;
+
 	return snprintf(buf, PAGE_SIZE, "%d\n",
 			intel_gpu_freq(dev_priv,
 				       dev_priv->rps.cur_freq));
-- 
1.9.1