tegra124: Make the PLLX frequency selectable by model.

The PLLX provides the clock for the main cores which can run at different max
frequencies depending on the specific model of Tegra124. This change makes it
possible to select a model which will, in turn, select a frequency for PLLX.
The default is 2GHz which is the lowest maximum frequency.

BUG=chrome-os-partner:25467
TEST=Booted on nyan rev1. Verified that the selected PLLX frequency was 2GHz.
With a change that selects the right model for nyan, verified that the
corresponding frequency was selected.
BRANCH=None

Original-Change-Id: Iee3a615083dee97ad659ff41cbf867af2a0c325d
Original-Signed-off-by: Gabe Black <gabeblack@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/188602
Original-Reviewed-by: Gabe Black <gabeblack@chromium.org>
Original-Commit-Queue: Gabe Black <gabeblack@chromium.org>
Original-Tested-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 1282015048420a518e6c6959ce982be70378211a)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I448a830f3184ad1afeadbd1c2974c7a27b03a923
Reviewed-on: http://review.coreboot.org/7409
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>

3 files changed, 39 insertions, 9 deletions

diff --git a/src/soc/nvidia/tegra124/Kconfig b/src/soc/nvidia/tegra124/Kconfig
index 3876a9e39c..bdc4af9528 100644
--- a/src/soc/nvidia/tegra124/Kconfig
+++ b/src/soc/nvidia/tegra124/Kconfig
@@ -91,4 +91,25 @@ config CBFS_CACHE_SIZE
 	hex "size of CBFS cache data"
 	default 0x00018000
 
+config TEGRA124_MODEL_TD570D
+	bool "TD570D"
+
+config TEGRA124_MODEL_TD580D
+	bool "TD580D"
+
+config TEGRA124_MODEL_CD570M
+	bool "CD570M"
+
+config TEGRA124_MODEL_CD580M
+	bool "CD580M"
+
+# Default to 2GHz, the lowest maximum frequency.
+config PLLX_KHZ
+	int
+	default 2000000 if TEGRA124_MODEL_TD570D
+	default 2300000 if TEGRA124_MODEL_TD580D
+	default 2100000 if TEGRA124_MODEL_CD570M
+	default 2300000 if TEGRA124_MODEL_CD580M
+	default 2000000
+
 endif
diff --git a/src/soc/nvidia/tegra124/clock.c b/src/soc/nvidia/tegra124/clock.c
index a642a7bcd4..7977bbe0d9 100644
--- a/src/soc/nvidia/tegra124/clock.c
+++ b/src/soc/nvidia/tegra124/clock.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright 2014 Google Inc.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -83,7 +84,7 @@ union __attribute__((transparent_union)) pll_fields {
  * Yes, it really is one equation with three unknowns ... */
 struct {
 	int khz;
-	struct pllcx_dividers	pllx;	/* target: 1900 MHz */
+	struct pllcx_dividers	pllx;	/* target:  CONFIG_PLLX_KHZ */
 	struct pllpad_dividers	pllp;	/* target:  408 MHz */
 	struct pllcx_dividers	pllc;	/* target:  600 MHz */
 	struct pllpad_dividers	plld;	/* target:  925 MHz */
@@ -93,7 +94,7 @@ struct {
 } static const osc_table[16] = {
 	[OSC_FREQ_OSC12]{
 		.khz = 12000,
-		.pllx = {.n = 158, .m =  1, .p = 0},		  /* 1896 MHz */
+		.pllx = {.n = TEGRA_PLLX_KHZ / 12000, .m =  1, .p = 0},
 		.pllp = {.n =  34, .m =  1, .p = 0, .cpcon = 2},
 		.pllc = {.n =  50, .m =  1, .p = 0},
 		.plld = {.n = 283, .m = 12, .p = 0, .cpcon = 8}, /* 283 MHz */
@@ -103,7 +104,7 @@ struct {
 	},
 	[OSC_FREQ_OSC13]{
 		.khz = 13000,
-		.pllx = {.n = 146, .m =  1, .p = 0},		  /* 1898 MHz */
+		.pllx = {.n = TEGRA_PLLX_KHZ / 13000, .m =  1, .p = 0},
 		.pllp = {.n = 408, .m = 13, .p = 0, .cpcon = 8},
 		.pllc = {.n = 231, .m =  5, .p = 0},		 /* 600.6 MHz */
 		.plld = {.n = 283, .m = 13, .p = 0, .cpcon = 8}, /* 283 MHz*/
@@ -113,7 +114,7 @@ struct {
 	},
 	[OSC_FREQ_OSC16P8]{
 		.khz = 16800,
-		.pllx = {.n = 113, .m =  1, .p = 0},		/* 1898.4 MHz */
+		.pllx = {.n = TEGRA_PLLX_KHZ / 16800, .m =  1, .p = 0},
 		.pllp = {.n = 170, .m =  7, .p = 0, .cpcon = 4},
 		.pllc = {.n = 250, .m =  7, .p = 0},
 		.plld = {.n = 286, .m = 17, .p = 0, .cpcon = 8}, /* 282.6 MHz*/
@@ -123,7 +124,7 @@ struct {
 	},
 	[OSC_FREQ_OSC19P2]{
 		.khz = 19200,
-		.pllx = {.n =  98, .m =  1, .p = 0},		/* 1881.6 MHz */
+		.pllx = {.n = TEGRA_PLLX_KHZ / 19200, .m =  1, .p = 0},
 		.pllp = {.n =  85, .m =  4, .p = 0, .cpcon = 3},
 		.pllc = {.n = 125, .m =  4, .p = 0},
 		.plld = {.n = 251, .m = 17, .p = 0, .cpcon = 8}, /* 283.5 MHz */
@@ -133,7 +134,7 @@ struct {
 	},
 	[OSC_FREQ_OSC26]{
 		.khz = 26000,
-		.pllx = {.n =  73, .m =  1, .p = 0},		  /* 1898 MHz */
+		.pllx = {.n = TEGRA_PLLX_KHZ / 26000, .m =  1, .p = 0},
 		.pllp = {.n = 204, .m = 13, .p = 0, .cpcon = 5},
 		.pllc = {.n =  23, .m =  1, .p = 0},		   /* 598 MHz */
 		.plld = {.n = 283, .m = 26, .p = 0, .cpcon = 8}, /* 283 MHz */
@@ -143,7 +144,11 @@ struct {
 	},
 	[OSC_FREQ_OSC38P4]{
 		.khz = 38400,
-		.pllx = {.n =  98, .m =  1, .p = 0},		/* 1881.6 MHz */
+		/*
+		 * There is a predivide by 2 before this PLL. Its values
+		 * should match the 19.2MHz values.
+		 */
+		.pllx = {.n = TEGRA_PLLX_KHZ / 19200, .m =  1, .p = 0},
 		.pllp = {.n =  85, .m =  4, .p = 0, .cpcon = 3},
 		.pllc = {.n = 125, .m =  4, .p = 0},
 		.plld = {.n = 125, .m = 17, .p = 0, .cpcon = 8}, /* 282.4 MHz */
@@ -153,7 +158,11 @@ struct {
 	},
 	[OSC_FREQ_OSC48]{
 		.khz = 48000,
-		.pllx = {.n = 158, .m =  1, .p = 0},		  /* 1896 MHz */
+		/*
+		 * There is a predivide by 4 before this PLL. Its values
+		 * should match the 12MHz values.
+		 */
+		.pllx = {.n = TEGRA_PLLX_KHZ / 12000, .m =  1, .p = 0},
 		.pllp = {.n =  24, .m =  1, .p = 0, .cpcon = 2},
 		.pllc = {.n =  50, .m =  1, .p = 0},
 		.plld = {.n = 71, .m = 12, .p = 0, .cpcon = 8}, /* 284 MHz */
diff --git a/src/soc/nvidia/tegra124/include/soc/clock.h b/src/soc/nvidia/tegra124/include/soc/clock.h
index 89be88b020..9f3f0a48d9 100644
--- a/src/soc/nvidia/tegra124/include/soc/clock.h
+++ b/src/soc/nvidia/tegra124/include/soc/clock.h
@@ -238,7 +238,7 @@ enum clock_source {  /* Careful: Not true for all sources, always check TRM! */
 
 /* soc-specific */
 #define TEGRA_CLK_M_KHZ	 clock_get_osc_khz()
-#define TEGRA_PLLX_KHZ   (1900000)
+#define TEGRA_PLLX_KHZ   CONFIG_PLLX_KHZ
 #define TEGRA_PLLP_KHZ   (408000)
 #define TEGRA_PLLC_KHZ   (600000)
 #define TEGRA_PLLD_KHZ   (925000)