MGS-4111 [#imx-1117] Fix displaying wrong governor values on 8QP

On 8QP we don't have the OVERDRIVE governor, only NOMINAL and
UNDERDRIVE.  We set the current initial governor to OVERDRIVE, but also
display incorrect governor names relative to the clocks assigned in OPP
tuples.  This patch address this situation by determining which governor
should be used at start-up and fixes displaying the governors
available for use.

This patch also sets the initial clock rate, in case the assigned-clock
rates for the cores are different than the ones found in the
operating-points (OPP). While this shouldn't be a real use-case this
allows testing different OPP tuples to mimic a OPP array for 8QP.

Signed-off-by: Marius Vlad <marius-cristian.vlad@nxp.com>

1 files changed, 73 insertions, 14 deletions

diff --git a/drivers/mxc/gpu-viv/hal/os/linux/kernel/platform/freescale/gc_hal_kernel_platform_imx.c b/drivers/mxc/gpu-viv/hal/os/linux/kernel/platform/freescale/gc_hal_kernel_platform_imx.c
index 49b0fe31569a..f8f94a2fcbda 100644
--- a/drivers/mxc/gpu-viv/hal/os/linux/kernel/platform/freescale/gc_hal_kernel_platform_imx.c
+++ b/drivers/mxc/gpu-viv/hal/os/linux/kernel/platform/freescale/gc_hal_kernel_platform_imx.c
@@ -431,24 +431,31 @@ static ssize_t gpu_govern_show(struct device_driver *dev, char *buf)
     struct imx_priv *priv = &imxPriv;
     int i;
     ssize_t len;
+    int nr_modes;
 
     unsigned long core_freq;
     unsigned long shader_freq;
 
+    if (priv->imx_gpu_govern.num_modes == GOVERN_COUNT)
+	    nr_modes = priv->imx_gpu_govern.num_modes - 1;
+    else
+	    nr_modes = priv->imx_gpu_govern.num_modes;
+
     len = sprintf(buf, "GPU support %d modes\n", priv->imx_gpu_govern.num_modes);
 
-    for (i = 0; i < priv->imx_gpu_govern.num_modes; i++)
+
+    for (i = priv->imx_gpu_govern.current_mode; i <= nr_modes; i++)
     {
-        core_freq   = priv->imx_gpu_govern.core_clk_freq[i];
-        shader_freq = priv->imx_gpu_govern.shader_clk_freq[i];
+	    core_freq   = priv->imx_gpu_govern.core_clk_freq[i];
+	    shader_freq = priv->imx_gpu_govern.shader_clk_freq[i];
 
-        len += sprintf(buf + len,
-            "%s:\tcore_clk frequency: %lu\tshader_clk frequency: %lu\n",
-            govern_modes[i], core_freq, shader_freq);
+	    len += sprintf(buf + len,
+			    "%s:\tcore_clk frequency: %lu\tshader_clk frequency: %lu\n",
+			    govern_modes[i], core_freq, shader_freq);
     }
 
     len += sprintf(buf + len, "Currently GPU runs on mode %s\n",
-        govern_modes[priv->imx_gpu_govern.current_mode]);
+		    govern_modes[priv->imx_gpu_govern.current_mode]);
 
     return len;
 }
@@ -503,11 +510,16 @@ int init_gpu_opp_table(struct device *dev)
     const __be32 *val;
     int nr;
     int ret = 0;
-    int i;
+    int i, p;
+    int core = gcvCORE_MAJOR;
     struct imx_priv *priv = &imxPriv;
 
+    struct clk *clk_core;
+    struct clk *clk_shader;
+
+    unsigned long core_freq, shader_freq;
+
     priv->imx_gpu_govern.num_modes = 0;
-    priv->imx_gpu_govern.current_mode = OVERDRIVE;
 
     prop = of_find_property(dev->of_node, "operating-points", NULL);
     if (!prop) {
@@ -529,9 +541,23 @@ int init_gpu_opp_table(struct device *dev)
         return -EINVAL;
     }
 
+    /*
+     * We handle both cases where UNDERDRIVE is represented by a single tuple
+     * or when it is represented by two. More than 4 tuples means that we have
+     * the current mode defaulting to OVERDRIVE, while less than 3 means only
+     * nominal. Lastly just two tuples means UNDERDRIVE. Note that the tuples
+     * are divisible by 2 (X Y) hence there's no need to test for odd values.
+     */
+    if (nr < 6)
+	    priv->imx_gpu_govern.current_mode = UNDERDRIVE;
+    else if (nr == 6 || nr == 8)
+	    priv->imx_gpu_govern.current_mode = NOMINAL;
+    else
+	    priv->imx_gpu_govern.current_mode = OVERDRIVE;
+
     val = prop->value;
 
-    for (i = 0; nr > 0 && i < GOVERN_COUNT; nr -= 4)
+    for (p = 0, i = priv->imx_gpu_govern.current_mode; nr > 0 && i < GOVERN_COUNT; nr -= 4)
     {
         unsigned long core_freq, core_volt, shader_freq, shader_volt;
 
@@ -560,17 +586,44 @@ int init_gpu_opp_table(struct device *dev)
         priv->imx_gpu_govern.core_clk_freq[i]   = core_freq;
         priv->imx_gpu_govern.shader_clk_freq[i] = shader_freq;
 
-        i++;
+        p++;
+	i++;
     }
 
-    priv->imx_gpu_govern.num_modes = i;
+    priv->imx_gpu_govern.num_modes = p;
     priv->imx_gpu_govern.dev = dev;
 
     if (priv->imx_gpu_govern.num_modes > 0)
     {
         ret = driver_create_file(dev->driver, &driver_attr_gpu_govern);
-        if (ret)
+        if (ret) {
             dev_err(dev, "create gpu_govern attr failed (%d)\n", ret);
+	    return ret;
+	}
+
+	/*
+	 * This could be redundant, but it is useful for testing DTS with
+	 * different OPPs that have assigned-clock rates different than the
+	 * ones specified in OPP tuple array. Otherwise we will display
+	 * different clock values when the driver is loaded. Further
+	 * modifications of the governor will display correctly but not when
+	 * the driver has been loaded.
+	 */
+	core_freq = priv->imx_gpu_govern.core_clk_freq[priv->imx_gpu_govern.current_mode];
+	shader_freq = priv->imx_gpu_govern.shader_clk_freq[priv->imx_gpu_govern.current_mode];
+
+	if (core_freq && shader_freq) {
+		for (; core <= gcvCORE_3D_MAX; core++) {
+			clk_core = priv->imx_gpu_clks[core].clk_core;
+			clk_shader = priv->imx_gpu_clks[core].clk_shader;
+
+			if (clk_core != NULL && clk_shader != NULL) {
+				clk_set_rate(clk_core, core_freq);
+				clk_set_rate(clk_shader, shader_freq);
+			}
+		}
+	}
+
     }
 
     return ret;
@@ -581,8 +634,14 @@ int remove_gpu_opp_table(void)
     struct imx_priv *priv = &imxPriv;
     struct device* dev = priv->imx_gpu_govern.dev;
     int i = 0;
+    int nr_modes;
+
+    if (priv->imx_gpu_govern.num_modes == GOVERN_COUNT)
+	    nr_modes = priv->imx_gpu_govern.num_modes - 1;
+    else
+	    nr_modes = priv->imx_gpu_govern.num_modes;
 
-    for (i = 0; i < priv->imx_gpu_govern.num_modes; i++)
+    for (i = priv->imx_gpu_govern.current_mode; i <= nr_modes; i++)
     {
         unsigned long core_freq;