ARM: tegra: don't exceed AVP limits when configuring PLLP

Based on the Tegra TRM, the system clock (which is the AVP clock) can
run up to 275MHz. On power on, the default sytem clock source is set to
PLLP_OUT0. In function clock_early_init(), PLLP_OUT0 will be set to
408MHz which is beyond system clock's upper limit.

The fix is to set the system clock to CLK_M before initializing PLLP,
and then switch back to PLLP_OUT4, which has an appropriate divider
configured, after PLLP has been configured

Implement this logic in new function tegra30_set_up_pllp(),
which sets up PLLP and all PLLP_OUT* dividers, and handles the AVP
clock switching. Remove the duplicate PLLP setup from pllx_set_rate()
and adjust_pllp_out_freqs().

Signed-off-by: Jimmy Zhang <jimmzhang@nvidia.com>
[swarren, significantly refactored the change]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>

3 files changed, 3 insertions, 51 deletions

diff --git a/arch/arm/cpu/arm720t/tegra-common/cpu.c b/arch/arm/cpu/arm720t/tegra-common/cpu.c
index 72c69b914c..03f67b163c 100644
--- a/arch/arm/cpu/arm720t/tegra-common/cpu.c
+++ b/arch/arm/cpu/arm720t/tegra-common/cpu.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010-2012, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2010-2014, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -114,24 +114,6 @@ struct clk_pll_table tegra_pll_x_table[TEGRA_SOC_CNT][CLOCK_OSC_FREQ_COUNT] = {
 	},
 };
 
-void adjust_pllp_out_freqs(void)
-{
-	struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
-	struct clk_pll *pll = &clkrst->crc_pll[CLOCK_ID_PERIPH];
-	u32 reg;
-
-	/* Set T30 PLLP_OUT1, 2, 3 & 4 freqs to 9.6, 48, 102 & 204MHz */
-	reg = readl(&pll->pll_out[0]);	/* OUTA, contains OUT2 / OUT1 */
-	reg |= (IN_408_OUT_48_DIVISOR << PLLP_OUT2_RATIO) | PLLP_OUT2_OVR
-		| (IN_408_OUT_9_6_DIVISOR << PLLP_OUT1_RATIO) | PLLP_OUT1_OVR;
-	writel(reg, &pll->pll_out[0]);
-
-	reg = readl(&pll->pll_out[1]);   /* OUTB, contains OUT4 / OUT3 */
-	reg |= (IN_408_OUT_204_DIVISOR << PLLP_OUT4_RATIO) | PLLP_OUT4_OVR
-		| (IN_408_OUT_102_DIVISOR << PLLP_OUT3_RATIO) | PLLP_OUT3_OVR;
-	writel(reg, &pll->pll_out[1]);
-}
-
 int pllx_set_rate(struct clk_pll_simple *pll , u32 divn, u32 divm,
 		u32 divp, u32 cpcon)
 {
@@ -207,12 +189,6 @@ void init_pllx(void)
 	/* set pllx */
 	sel = &tegra_pll_x_table[chip_sku][osc];
 	pllx_set_rate(pll, sel->n, sel->m, sel->p, sel->cpcon);
-
-	/* adjust PLLP_out1-4 on T3x/T114 */
-	if (soc_type >= CHIPID_TEGRA30) {
-		debug("  init_pllx: adjusting PLLP out freqs\n");
-		adjust_pllp_out_freqs();
-	}
 }
 
 void enable_cpu_clock(int enable)
diff --git a/arch/arm/cpu/arm720t/tegra114/cpu.c b/arch/arm/cpu/arm720t/tegra114/cpu.c
index 7a1747a3be..385e1a1c86 100644
--- a/arch/arm/cpu/arm720t/tegra114/cpu.c
+++ b/arch/arm/cpu/arm720t/tegra114/cpu.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010-2013, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2010-2014, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -126,18 +126,6 @@ void t114_init_clocks(void)
 	/* Set active CPU cluster to G */
 	clrbits_le32(&flow->cluster_control, 1);
 
-	/*
-	 * Switch system clock to PLLP_OUT4 (108 MHz), AVP will now run
-	 * at 108 MHz. This is glitch free as only the source is changed, no
-	 * special precaution needed.
-	 */
-	val = (SCLK_SOURCE_PLLP_OUT4 << SCLK_SWAKEUP_FIQ_SOURCE_SHIFT) |
-		(SCLK_SOURCE_PLLP_OUT4 << SCLK_SWAKEUP_IRQ_SOURCE_SHIFT) |
-		(SCLK_SOURCE_PLLP_OUT4 << SCLK_SWAKEUP_RUN_SOURCE_SHIFT) |
-		(SCLK_SOURCE_PLLP_OUT4 << SCLK_SWAKEUP_IDLE_SOURCE_SHIFT) |
-		(SCLK_SYS_STATE_RUN << SCLK_SYS_STATE_SHIFT);
-	writel(val, &clkrst->crc_sclk_brst_pol);
-
 	writel(SUPER_SCLK_ENB_MASK, &clkrst->crc_super_sclk_div);
 
 	debug("Setting up PLLX\n");
diff --git a/arch/arm/cpu/arm720t/tegra30/cpu.c b/arch/arm/cpu/arm720t/tegra30/cpu.c
index e162357484..a80648389c 100644
--- a/arch/arm/cpu/arm720t/tegra30/cpu.c
+++ b/arch/arm/cpu/arm720t/tegra30/cpu.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010-2012, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2010-2014, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -84,18 +84,6 @@ void t30_init_clocks(void)
 	/* Set active CPU cluster to G */
 	clrbits_le32(flow->cluster_control, 1 << 0);
 
-	/*
-	 * Switch system clock to PLLP_OUT4 (108 MHz), AVP will now run
-	 * at 108 MHz. This is glitch free as only the source is changed, no
-	 * special precaution needed.
-	 */
-	val = (SCLK_SOURCE_PLLP_OUT4 << SCLK_SWAKEUP_FIQ_SOURCE_SHIFT) |
-		(SCLK_SOURCE_PLLP_OUT4 << SCLK_SWAKEUP_IRQ_SOURCE_SHIFT) |
-		(SCLK_SOURCE_PLLP_OUT4 << SCLK_SWAKEUP_RUN_SOURCE_SHIFT) |
-		(SCLK_SOURCE_PLLP_OUT4 << SCLK_SWAKEUP_IDLE_SOURCE_SHIFT) |
-		(SCLK_SYS_STATE_RUN << SCLK_SYS_STATE_SHIFT);
-	writel(val, &clkrst->crc_sclk_brst_pol);
-
 	writel(SUPER_SCLK_ENB_MASK, &clkrst->crc_super_sclk_div);
 
 	val = (0 << CLK_SYS_RATE_HCLK_DISABLE_SHIFT) |