gpu: nvgpu: use platform data for ptimer source rate

Instead of depending on clock frame-work, use platform data
for ptimer source rate. Removed ptimerscaling10x platform
data, and use ptimer source frequency to calculate
ptimerscaling factor.

Reviewed-on: http://git-master/r/819030
(cherry picked from commit dd291334d54dab80cab7eb1656dffc48a59610b4)

Change-Id: I7638ce9875a6e440bbfc2ba2da0d0b094b2700ff
Signed-off-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
Reviewed-on: http://git-master/r/827300
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

drivers/gpu/nvgpu/gk20a/channel_gk20a.c

@@ -138,7 +138,7 @@ int gk20a_channel_get_timescale_from_timeslice(struct gk20a *g,
 {
 	struct gk20a_platform *platform = platform_get_drvdata(g->dev);
 	int value = scale_ptimer(timeslice_period,
-			platform->ptimerscaling10x);
+			ptimer_scalingfactor10x(platform->ptimer_src_freq));
 	int shift = 3;
 
 	/* value field is 8 bits long */

drivers/gpu/nvgpu/gk20a/fifo_gk20a.c

@@ -410,7 +410,8 @@ int gk20a_init_fifo_reset_enable_hw(struct gk20a *g)
 		g->ops.fifo.apply_pb_timeout(g);
 
 	timeout = GRFIFO_TIMEOUT_CHECK_PERIOD_US;
-	timeout = scale_ptimer(timeout, platform->ptimerscaling10x);
+	timeout = scale_ptimer(timeout,
+		ptimer_scalingfactor10x(platform->ptimer_src_freq));
 	timeout |= fifo_eng_timeout_detection_enabled_f();
 	gk20a_writel(g, fifo_eng_timeout_r(), timeout);
 

drivers/gpu/nvgpu/gk20a/gk20a.h

@@ -50,6 +50,10 @@ struct acr_gm20b;
 #include "cde_gk20a.h"
 #include "debug_gk20a.h"
 
+/* PTIMER_REF_FREQ_HZ corresponds to a period of 32 nanoseconds.
+    32 ns is the resolution of ptimer. */
+#define PTIMER_REF_FREQ_HZ                      31250000
+
 struct cooling_device_gk20a {
 	struct thermal_cooling_device *gk20a_cooling_dev;
 	unsigned int gk20a_freq_state;
@@ -901,6 +905,10 @@ void gk20a_user_deinit(struct platform_device *dev);
 
 extern void gk20a_debug_dump_device(struct platform_device *pdev);
 
+static inline u32 ptimer_scalingfactor10x(u32 ptimer_src_freq)
+{
+	return (u32)(((u64)(PTIMER_REF_FREQ_HZ * 10)) / ptimer_src_freq);
+}
 static inline u32 scale_ptimer(u32 timeout , u32 scale10x)
 {
 	if (((timeout*10) % scale10x) >= (scale10x/2))

drivers/gpu/nvgpu/gk20a/gk20a_sysfs.c

@@ -23,7 +23,6 @@
 #include <linux/kernel.h>
 #include <linux/fb.h>
 #include <linux/gk20a.h>
-
 #include <mach/clk.h>
 
 #include "gk20a.h"
@@ -33,9 +32,6 @@
 
 
 #define PTIMER_FP_FACTOR			1000000
-/* PTIMER_REF_FREQ_HZ corresponds to a period of 32 nanoseconds. 32 ns is
-   the resolution of ptimer. */
-#define PTIMER_REF_FREQ_HZ			31250000
 
 #define ROOTRW (S_IRWXU|S_IRGRP|S_IROTH)
 
@@ -208,17 +204,27 @@ static ssize_t ptimer_scale_factor_show(struct device *dev,
 						struct device_attribute *attr,
 						char *buf)
 {
-	u32 tsc_freq_hz = clk_get_rate(clk_get_sys(NULL, "clk_m"));
-	u32 scaling_factor_fp = (u32)(PTIMER_REF_FREQ_HZ) /
-				((u32)(tsc_freq_hz) /
+	struct gk20a_platform *platform = dev_get_drvdata(dev);
+	u32 src_freq_hz = platform->ptimer_src_freq;
+	u32 scaling_factor_fp;
+	ssize_t res;
+
+	if (!src_freq_hz) {
+		dev_err(dev, "reference clk_m rate is not set correctly\n");
+		return -EINVAL;
+	}
+
+	scaling_factor_fp = (u32)(PTIMER_REF_FREQ_HZ) /
+				((u32)(src_freq_hz) /
 				(u32)(PTIMER_FP_FACTOR));
-	ssize_t res = snprintf(buf,
+	res = snprintf(buf,
 				PAGE_SIZE,
 				"%u.%u\n",
 				scaling_factor_fp / PTIMER_FP_FACTOR,
 				scaling_factor_fp % PTIMER_FP_FACTOR);
 
 	return res;
+
 }
 
 static DEVICE_ATTR(ptimer_scale_factor,

drivers/gpu/nvgpu/gk20a/platform_gk20a.h

@@ -97,9 +97,6 @@ struct gk20a_platform {
 	/* Default big page size 64K or 128K */
 	u32 default_big_page_size;
 
-	/* scaling factor for ptimer */
-	u32  ptimerscaling10x;
-
 	/* Initialize the platform interface of the gk20a driver.
 	 *
 	 * The platform implementation of this function must
@@ -191,6 +188,8 @@ struct gk20a_platform {
 	u64 virt_handle;
 	struct task_struct *intr_handler;
 #endif
+	/* source frequency for ptimer in hz */
+	u32 ptimer_src_freq;
 
 	bool has_cde;
 };

drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c

@@ -812,7 +812,7 @@ struct gk20a_platform gk20a_tegra_platform = {
 	.enable_elcg            = true,
 	.enable_elpg            = true,
 	.enable_aelpg           = true,
-	.ptimerscaling10x	= 26,
+	.ptimer_src_freq	= 12000000,
 
 	.force_reset_in_do_idle = false,
 
@@ -861,7 +861,7 @@ struct gk20a_platform gm20b_tegra_platform = {
 	.enable_elcg            = true,
 	.enable_elpg            = true,
 	.enable_aelpg           = true,
-	.ptimerscaling10x	= 26,
+	.ptimer_src_freq	= 19200000,
 
 	.force_reset_in_do_idle = false,