drm/etnaviv: enable GPU module level clock gating support

Enable GPU module level hardware clock gating, using the conditions
found in the galcore v5 driver.

v2 lst: Split out clock gating enable into separate function, as
there might be more conditions needed for new hardware.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

@@ -487,6 +487,47 @@ static int etnaviv_hw_reset(struct etnaviv_gpu *gpu)
 	return 0;
 }
 
+static void etnaviv_gpu_enable_mlcg(struct etnaviv_gpu *gpu)
+{
+	u32 pmc, ppc;
+
+	/* enable clock gating */
+	ppc = gpu_read(gpu, VIVS_PM_POWER_CONTROLS);
+	ppc |= VIVS_PM_POWER_CONTROLS_ENABLE_MODULE_CLOCK_GATING;
+
+	/* Disable stall module clock gating for 4.3.0.1 and 4.3.0.2 revs */
+	if (gpu->identity.revision == 0x4301 ||
+	    gpu->identity.revision == 0x4302)
+		ppc |= VIVS_PM_POWER_CONTROLS_DISABLE_STALL_MODULE_CLOCK_GATING;
+
+	gpu_write(gpu, VIVS_PM_POWER_CONTROLS, ppc);
+
+	pmc = gpu_read(gpu, VIVS_PM_MODULE_CONTROLS);
+
+	/* Disable PA clock gating for GC400+ except for GC420 */
+	if (gpu->identity.model >= chipModel_GC400 &&
+	    gpu->identity.model != chipModel_GC420)
+		pmc |= VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_PA;
+
+	/*
+	 * Disable PE clock gating on revs < 5.0.0.0 when HZ is
+	 * present without a bug fix.
+	 */
+	if (gpu->identity.revision < 0x5000 &&
+	    gpu->identity.minor_features0 & chipMinorFeatures0_HZ &&
+	    !(gpu->identity.minor_features1 &
+	      chipMinorFeatures1_DISABLE_PE_GATING))
+		pmc |= VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_PE;
+
+	if (gpu->identity.revision < 0x5422)
+		pmc |= BIT(15); /* Unknown bit */
+
+	pmc |= VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_RA_HZ;
+	pmc |= VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_RA_EZ;
+
+	gpu_write(gpu, VIVS_PM_MODULE_CONTROLS, pmc);
+}
+
 static void etnaviv_gpu_hw_init(struct etnaviv_gpu *gpu)
 {
 	u16 prefetch;
@@ -506,6 +547,9 @@ static void etnaviv_gpu_hw_init(struct etnaviv_gpu *gpu)
 		gpu_write(gpu, VIVS_MC_DEBUG_MEMORY, mc_memory_debug);
 	}
 
+	/* enable module-level clock gating */
+	etnaviv_gpu_enable_mlcg(gpu);
+
 	/*
 	 * Update GPU AXI cache atttribute to "cacheable, no allocate".
 	 * This is necessary to prevent the iMX6 SoC locking up.

drivers/gpu/drm/etnaviv/state_hi.xml.h

@@ -218,6 +218,13 @@ Copyright (C) 2015
 #define VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_FE	0x00000001
 #define VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_DE	0x00000002
 #define VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_PE	0x00000004
+#define VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_SH	0x00000008
+#define VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_PA	0x00000010
+#define VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_SE	0x00000020
+#define VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_RA	0x00000040
+#define VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_TX	0x00000080
+#define VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_RA_EZ	0x00010000
+#define VIVS_PM_MODULE_CONTROLS_DISABLE_MODULE_CLOCK_GATING_RA_HZ	0x00020000
 
 #define VIVS_PM_MODULE_STATUS					0x00000108
 #define VIVS_PM_MODULE_STATUS_MODULE_CLOCK_GATED_FE		0x00000001