[U-Boot] [PATCH V2] ARM: tegra: don't exceed AVP limits when configuring PLLP

Stephen Warren
2014-01-23T18:58:13Z

From: Jimmy Zhang <jimmzhang@nvidia.com>

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_or_later_adjust_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>
---
v2:
* Remove duplicate adjustment of PLLP dividers from pllx_set_rate()
* Adjust PLLP_OUT1/PLLP_OUT2 dividers from clock_early_init() so that
everything related to PLLP is set up at once.
* Initialize PLLP from a new common function tegra30_or_later_adjust_pllp()
so the code isn't duplicated.
---
arch/arm/cpu/arm720t/tegra-common/cpu.c | 26 +--------
arch/arm/cpu/arm720t/tegra114/cpu.c | 14 +----
arch/arm/cpu/arm720t/tegra30/cpu.c | 14 +----
arch/arm/cpu/tegra-common/clock.c | 90 ++++++++++++++++++++++++++++++-
arch/arm/cpu/tegra114-common/clock.c | 8 ++-
arch/arm/cpu/tegra30-common/clock.c | 31 +----------
arch/arm/include/asm/arch-tegra/clk_rst.h | 16 +++++-
arch/arm/include/asm/arch-tegra/clock.h | 2 +
8 files changed, 114 insertions(+), 87 deletions(-)

diff --git a/arch/arm/cpu/arm720t/tegra-common/cpu.c b/arch/arm/cpu/arm720t/tegra-common/cpu.c
index 72c69b914c7f..03f67b163cc5 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 7a1747a3beb8..385e1a1c86e0 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 e16235748449..a80648389c7c 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
- *@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) |
diff --git a/arch/arm/cpu/tegra-common/clock.c b/arch/arm/cpu/tegra-common/clock.c
index 33bb19084b8c..18579b7f98b3 100644
--- a/arch/arm/cpu/tegra-common/clock.c
+++ b/arch/arm/cpu/tegra-common/clock.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,
@@ -575,3 +575,91 @@ void clock_init(void)
/* Do any special system timer/TSC setup */
arch_timer_init();
}
+
+static void set_avp_clock_to(u32 src)
+{
+ struct clk_rst_ctlr *clkrst =
+ (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+ u32 val;
+
+ val = (src << SCLK_SWAKEUP_FIQ_SOURCE_SHIFT) |
+ (src << SCLK_SWAKEUP_IRQ_SOURCE_SHIFT) |
+ (src << SCLK_SWAKEUP_RUN_SOURCE_SHIFT) |
+ (src << SCLK_SWAKEUP_IDLE_SOURCE_SHIFT) |
+ (SCLK_SYS_STATE_RUN << SCLK_SYS_STATE_SHIFT);
+ writel(val, &clkrst->crc_sclk_brst_pol);
+ udelay(3);
+}
+
+void tegra30_or_later_adjust_pllp(void)
+{
+ struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+ u32 reg;
+
+ /*
+ * 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. This function sets PLLP's (hence PLLP_OUT0's) rate 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
+ */
+ set_avp_clock_to(SCLK_SOURCE_CLKM);
+
+ /*
+ * PLLP output frequency set to 408Mhz
+ * PLLC output frequency set to 228Mhz
+ */
+ switch (clock_get_osc_freq()) {
+ case CLOCK_OSC_FREQ_12_0: /* OSC is 12Mhz */
+ clock_set_rate(CLOCK_ID_PERIPH, 408, 12, 0, 8);
+ clock_set_rate(CLOCK_ID_CGENERAL, 456, 12, 1, 8);
+ break;
+
+ case CLOCK_OSC_FREQ_26_0: /* OSC is 26Mhz */
+ clock_set_rate(CLOCK_ID_PERIPH, 408, 26, 0, 8);
+ clock_set_rate(CLOCK_ID_CGENERAL, 600, 26, 0, 8);
+ break;
+
+ case CLOCK_OSC_FREQ_13_0: /* OSC is 13Mhz */
+ clock_set_rate(CLOCK_ID_PERIPH, 408, 13, 0, 8);
+ clock_set_rate(CLOCK_ID_CGENERAL, 600, 13, 0, 8);
+ break;
+ case CLOCK_OSC_FREQ_19_2:
+ default:
+ /*
+ * These are not supported. It is too early to print a
+ * message and the UART likely won't work anyway due to the
+ * oscillator being wrong.
+ */
+ break;
+ }
+
+ /* Set PLLP_OUT1, 2, 3 & 4 freqs to 9.6, 48, 102 & 204MHz */
+
+ /* OUT1, 2 */
+ /* Assert RSTN before enable */
+ reg = PLLP_OUT2_RSTN_EN | PLLP_OUT1_RSTN_EN;
+ writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[0]);
+ /* Set divisor and reenable */
+ reg = (IN_408_OUT_48_DIVISOR << PLLP_OUT2_RATIO)
+ | PLLP_OUT2_OVR | PLLP_OUT2_CLKEN | PLLP_OUT2_RSTN_DIS
+ | (IN_408_OUT_9_6_DIVISOR << PLLP_OUT1_RATIO)
+ | PLLP_OUT1_OVR | PLLP_OUT1_CLKEN | PLLP_OUT1_RSTN_DIS;
+ writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[0]);
+
+ /* OUT3, 4 */
+ /* Assert RSTN before enable */
+ reg = PLLP_OUT4_RSTN_EN | PLLP_OUT3_RSTN_EN;
+ writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[1]);
+ /* Set divisor and reenable */
+ reg = (IN_408_OUT_204_DIVISOR << PLLP_OUT4_RATIO)
+ | PLLP_OUT4_OVR | PLLP_OUT4_CLKEN | PLLP_OUT4_RSTN_DIS
+ | (IN_408_OUT_102_DIVISOR << PLLP_OUT3_RATIO)
+ | PLLP_OUT3_OVR | PLLP_OUT3_CLKEN | PLLP_OUT3_RSTN_DIS;
+ writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[1]);
+
+ set_avp_clock_to(SCLK_SOURCE_PLLP_OUT4);
+}
diff --git a/arch/arm/cpu/tegra114-common/clock.c b/arch/arm/cpu/tegra114-common/clock.c
index 3bede71a7a1f..8bc6e816cf95 100644
--- a/arch/arm/cpu/tegra114-common/clock.c
+++ b/arch/arm/cpu/tegra114-common/clock.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,
@@ -604,26 +604,24 @@ void clock_early_init(void)
struct clk_rst_ctlr *clkrst =
(struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;

+ tegra30_or_later_adjust_pllp();
+
/*
- * PLLP output frequency set to 408Mhz
* PLLC output frequency set to 600Mhz
* PLLD output frequency set to 925Mhz
*/
switch (clock_get_osc_freq()) {
case CLOCK_OSC_FREQ_12_0: /* OSC is 12Mhz */
- clock_set_rate(CLOCK_ID_PERIPH, 408, 12, 0, 8);
clock_set_rate(CLOCK_ID_CGENERAL, 600, 12, 0, 8);
clock_set_rate(CLOCK_ID_DISPLAY, 925, 12, 0, 12);
break;

case CLOCK_OSC_FREQ_26_0: /* OSC is 26Mhz */
- clock_set_rate(CLOCK_ID_PERIPH, 408, 26, 0, 8);
clock_set_rate(CLOCK_ID_CGENERAL, 600, 26, 0, 8);
clock_set_rate(CLOCK_ID_DISPLAY, 925, 26, 0, 12);
break;

case CLOCK_OSC_FREQ_13_0: /* OSC is 13Mhz */
- clock_set_rate(CLOCK_ID_PERIPH, 408, 13, 0, 8);
clock_set_rate(CLOCK_ID_CGENERAL, 600, 13, 0, 8);
clock_set_rate(CLOCK_ID_DISPLAY, 925, 13, 0, 12);
break;
diff --git a/arch/arm/cpu/tegra30-common/clock.c b/arch/arm/cpu/tegra30-common/clock.c
index 33528702185e..60b99347d1c0 100644
--- a/arch/arm/cpu/tegra30-common/clock.c
+++ b/arch/arm/cpu/tegra30-common/clock.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,
@@ -581,34 +581,7 @@ enum periph_id clk_id_to_periph_id(int clk_id)

void clock_early_init(void)
{
- /*
- * PLLP output frequency set to 408Mhz
- * PLLC output frequency set to 228Mhz
- */
- switch (clock_get_osc_freq()) {
- case CLOCK_OSC_FREQ_12_0: /* OSC is 12Mhz */
- clock_set_rate(CLOCK_ID_PERIPH, 408, 12, 0, 8);
- clock_set_rate(CLOCK_ID_CGENERAL, 456, 12, 1, 8);
- break;
-
- case CLOCK_OSC_FREQ_26_0: /* OSC is 26Mhz */
- clock_set_rate(CLOCK_ID_PERIPH, 408, 26, 0, 8);
- clock_set_rate(CLOCK_ID_CGENERAL, 600, 26, 0, 8);
- break;
-
- case CLOCK_OSC_FREQ_13_0: /* OSC is 13Mhz */
- clock_set_rate(CLOCK_ID_PERIPH, 408, 13, 0, 8);
- clock_set_rate(CLOCK_ID_CGENERAL, 600, 13, 0, 8);
- break;
- case CLOCK_OSC_FREQ_19_2:
- default:
- /*
- * These are not supported. It is too early to print a
- * message and the UART likely won't work anyway due to the
- * oscillator being wrong.
- */
- break;
- }
+ tegra30_or_later_adjust_pllp();
}

void arch_timer_init(void)
diff --git a/arch/arm/include/asm/arch-tegra/clk_rst.h b/arch/arm/include/asm/arch-tegra/clk_rst.h
index f07b83d26af4..021cfcc3c602 100644
--- a/arch/arm/include/asm/arch-tegra/clk_rst.h
+++ b/arch/arm/include/asm/arch-tegra/clk_rst.h
@@ -1,5 +1,5 @@
/*
- * (C) Copyright 2010,2011
+ * (C) Copyright 2010-2014
* NVIDIA Corporation <www.nvidia.com>
*
* SPDX-License-Identifier: GPL-2.0+
@@ -209,6 +209,20 @@ enum {
IN_408_OUT_9_6_DIVISOR = 83,
};

+#define PLLP_OUT1_RSTN_DIS (1 << 0)
+#define PLLP_OUT1_RSTN_EN (0 << 0)
+#define PLLP_OUT1_CLKEN (1 << 1)
+#define PLLP_OUT2_RSTN_DIS (1 << 16)
+#define PLLP_OUT2_RSTN_EN (0 << 16)
+#define PLLP_OUT2_CLKEN (1 << 17)
+
+#define PLLP_OUT3_RSTN_DIS (1 << 0)
+#define PLLP_OUT3_RSTN_EN (0 << 0)
+#define PLLP_OUT3_CLKEN (1 << 1)
+#define PLLP_OUT4_RSTN_DIS (1 << 16)
+#define PLLP_OUT4_RSTN_EN (0 << 16)
+#define PLLP_OUT4_CLKEN (1 << 17)
+
/* CLK_RST_CONTROLLER_UTMIP_PLL_CFG1_0 */
#define PLLU_POWERDOWN (1 << 16)
#define PLL_ENABLE_POWERDOWN (1 << 14)
diff --git a/arch/arm/include/asm/arch-tegra/clock.h b/arch/arm/include/asm/arch-tegra/clock.h
index 357d9c592b55..6c2fc7851198 100644
--- a/arch/arm/include/asm/arch-tegra/clock.h
+++ b/arch/arm/include/asm/arch-tegra/clock.h
@@ -320,4 +320,6 @@ int clock_set_rate(enum clock_id clkid, u32 n, u32 m, u32 p, u32 cpcon);
/* SoC-specific TSC init */
void arch_timer_init(void);

+void tegra30_or_later_adjust_pllp(void);
+
#endif /* _TEGRA_CLOCK_H_ */
--
1.8.1.5