drm/msm: Hard code the GPU "slow frequency"

Some A3XX and A4XX GPU targets required that the GPU clock be
programmed to a non zero value when it was disabled so
27Mhz was chosen as the "invalid" frequency.

Even though newer targets do not have the same clock restrictions
we still write 27Mhz on clock disable and expect the clock subsystem
to round down to zero.

For unknown reasons even though the slow clock speed is always
27Mhz and it isn't actually a functional level the legacy device tree
frequency tables always defined it and then did gymnastics to work
around it.

Instead of playing the same silly games just hard code the "slow" clock
speed in the code as 27MHz and save ourselves a bit of infrastructure.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

3 files changed, 4 insertions, 8 deletions

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
index bc170b7..9cae68b 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_device.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
@@ -2,7 +2,7 @@
  * Copyright (C) 2013-2014 Red Hat
  * Author: Rob Clark <robdclark@gmail.com>
  *
- * Copyright (c) 2014 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014,2017 The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
@@ -231,7 +231,6 @@ static int adreno_bind(struct device *dev, struct device *master, void *data)
 
 	/* find clock rates: */
 	config.fast_rate = 0;
-	config.slow_rate = ~0;
 	for_each_child_of_node(node, child) {
 		if (of_device_is_compatible(child, "qcom,gpu-pwrlevels")) {
 			struct device_node *pwrlvl;
@@ -242,7 +241,6 @@ static int adreno_bind(struct device *dev, struct device *master, void *data)
 					return ret;
 				}
 				config.fast_rate = max(config.fast_rate, val);
-				config.slow_rate = min(config.slow_rate, val);
 			}
 		}
 	}
@@ -251,7 +249,6 @@ static int adreno_bind(struct device *dev, struct device *master, void *data)
 		dev_warn(dev, "could not find clk rates\n");
 		/* This is a safe low speed for all devices: */
 		config.fast_rate = 200000000;
-		config.slow_rate = 27000000;
 	}
 
 	dev->platform_data = &config;
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 4cac226..5b63fc6 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -352,14 +352,13 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
 	adreno_gpu->rev = config->rev;
 
 	gpu->fast_rate = config->fast_rate;
-	gpu->slow_rate = config->slow_rate;
 	gpu->bus_freq  = config->bus_freq;
 #ifdef DOWNSTREAM_CONFIG_MSM_BUS_SCALING
 	gpu->bus_scale_table = config->bus_scale_table;
 #endif
 
-	DBG("fast_rate=%u, slow_rate=%u, bus_freq=%u",
-			gpu->fast_rate, gpu->slow_rate, gpu->bus_freq);
+	DBG("fast_rate=%u, slow_rate=27000000, bus_freq=%u",
+			gpu->fast_rate, gpu->bus_freq);
 
 	ret = msm_gpu_init(drm, pdev, &adreno_gpu->base, &funcs->base,
 			adreno_gpu->info->name, "kgsl_3d0_reg_memory", "kgsl_3d0_irq",
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
index 42e444a..fb4831f 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
@@ -123,7 +123,7 @@ struct adreno_gpu {
 /* platform config data (ie. from DT, or pdata) */
 struct adreno_platform_config {
 	struct adreno_rev rev;
-	uint32_t fast_rate, slow_rate, bus_freq;
+	uint32_t fast_rate, bus_freq;
 #ifdef DOWNSTREAM_CONFIG_MSM_BUS_SCALING
 	struct msm_bus_scale_pdata *bus_scale_table;
 #endif