clk: tegra210: fix PLLU and PLLU_OUT1

This change “clk: tegra210: fix PLLU and PLLU_OUT1” (commit 0d34dfb) in Linux kernel is authored by JC Kuo <jckuo [at] nvidia.com> on Wed Jun 12 11:14:34 2019 +0800.

Description of "clk: tegra210: fix PLLU and PLLU_OUT1"

The change “clk: tegra210: fix PLLU and PLLU_OUT1” introduces changes as follows.

clk: tegra210: fix PLLU and PLLU_OUT1

Full-speed and low-speed USB devices do not work with Tegra210
platforms because of incorrect PLLU/PLLU_OUT1 clock settings.

When full-speed device is connected:
[   14.059886] usb 1-3: new full-speed USB device number 2 using tegra-xusb
[   14.196295] usb 1-3: device descriptor read/64, error -71
[   14.436311] usb 1-3: device descriptor read/64, error -71
[   14.675749] usb 1-3: new full-speed USB device number 3 using tegra-xusb
[   14.812335] usb 1-3: device descriptor read/64, error -71
[   15.052316] usb 1-3: device descriptor read/64, error -71
[   15.164799] usb usb1-port3: attempt power cycle

When low-speed device is connected:
[   37.610949] usb usb1-port3: Cannot enable. Maybe the USB cable is bad?
[   38.557376] usb usb1-port3: Cannot enable. Maybe the USB cable is bad?
[   38.564977] usb usb1-port3: attempt power cycle

This commit fixes the issue by:
 1. initializing PLLU_OUT1 before initializing XUSB_FS_SRC clock
    because PLLU_OUT1 is parent of XUSB_FS_SRC.
 2. changing PLLU post-divider to /2 (DIVP=1) according to Technical
    Reference Manual.

Fixes: e745f992cf4b ("clk: tegra: Rework pll_u")
Signed-off-by: JC Kuo <jckuo@nvidia.com>
Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Linux kernel releases containing commit 0d34dfb

The Linux kernel releases containing this commit are as follows.

Linux kernel code changes from "clk: tegra210: fix PLLU and PLLU_OUT1"

There are 8 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 drivers/clk/tegra/clk-tegra210.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
 
diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
index ed3c7df75d1e..1be4d82d78cf 100644
--- a/drivers/clk/tegra/clk-tegra210.c
+++ b/drivers/clk/tegra/clk-tegra210.c
@@ -2215,9 +2215,9 @@ static struct div_nmp pllu_nmp = {
 };
 
 static struct tegra_clk_pll_freq_table pll_u_freq_table[] = {
-	{ 12000000, 480000000, 40, 1, 0, 0 },
-	{ 13000000, 480000000, 36, 1, 0, 0 }, /* actual: 468.0 MHz */
-	{ 38400000, 480000000, 25, 2, 0, 0 },
+	{ 12000000, 480000000, 40, 1, 1, 0 },
+	{ 13000000, 480000000, 36, 1, 1, 0 }, /* actual: 468.0 MHz */
+	{ 38400000, 480000000, 25, 2, 1, 0 },
 	{        0,         0,  0, 0, 0, 0 },
 };
 
@@ -3344,6 +3344,7 @@ static struct tegra_clk_init_table init_table[] __initdata = {
 	{ TEGRA210_CLK_DFLL_REF, TEGRA210_CLK_PLL_P, 51000000, 1 },
 	{ TEGRA210_CLK_SBC4, TEGRA210_CLK_PLL_P, 12000000, 1 },
 	{ TEGRA210_CLK_PLL_RE_VCO, TEGRA210_CLK_CLK_MAX, 672000000, 1 },
+	{ TEGRA210_CLK_PLL_U_OUT1, TEGRA210_CLK_CLK_MAX, 48000000, 1 },
 	{ TEGRA210_CLK_XUSB_GATE, TEGRA210_CLK_CLK_MAX, 0, 1 },
 	{ TEGRA210_CLK_XUSB_SS_SRC, TEGRA210_CLK_PLL_U_480M, 120000000, 0 },
 	{ TEGRA210_CLK_XUSB_FS_SRC, TEGRA210_CLK_PLL_U_48M, 48000000, 0 },
@@ -3368,7 +3369,6 @@ static struct tegra_clk_init_table init_table[] __initdata = {
 	{ TEGRA210_CLK_PLL_DP, TEGRA210_CLK_CLK_MAX, 270000000, 0 },
 	{ TEGRA210_CLK_SOC_THERM, TEGRA210_CLK_PLL_P, 51000000, 0 },
 	{ TEGRA210_CLK_CCLK_G, TEGRA210_CLK_CLK_MAX, 0, 1 },
-	{ TEGRA210_CLK_PLL_U_OUT1, TEGRA210_CLK_CLK_MAX, 48000000, 1 },
 	{ TEGRA210_CLK_PLL_U_OUT2, TEGRA210_CLK_CLK_MAX, 60000000, 1 },
 	{ TEGRA210_CLK_SPDIF_IN_SYNC, TEGRA210_CLK_CLK_MAX, 24576000, 0 },
 	{ TEGRA210_CLK_I2S0_SYNC, TEGRA210_CLK_CLK_MAX, 24576000, 0 },

The commit for this change in Linux stable tree is 0d34dfb (patch).

Last modified: 2020/02/08