2024-05-07 14:21:07

by André Draszik

Subject: [PATCH 5/5] phy: exynos5-usbdrd: set ref clk freq in exynos850_usbdrd_utmi_init()

While commit 255ec3879dd4 ("phy: exynos5-usbdrd: Add 26MHz ref clk
support") correctly states that CLKRSTCTRL[7:5] doesn't need to be set
on modern Exynos platforms, SSPPLLCTL[2:0] should be programmed with
the frequency of the reference clock for the USB2.0 phy instead.

I stumbled across this while adding support for the Google Tensor
gs101, but this should apply to E850 just the same.

Do so.

Fixes: 691525074db9 ("phy: exynos5-usbdrd: Add Exynos850 support")
Signed-off-by: André Draszik <[email protected]>

---
Feel free to drop the Fixes: if you think that is unwarranted here.

v2: add missing bitfield.h include (seems this is implied on some
platforms, but not on others)
---
drivers/phy/samsung/phy-exynos5-usbdrd.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)

diff --git a/drivers/phy/samsung/phy-exynos5-usbdrd.c b/drivers/phy/samsung/phy-exynos5-usbdrd.c
index 1da7a4881f72..15be966b50ae 100644
--- a/drivers/phy/samsung/phy-exynos5-usbdrd.c
+++ b/drivers/phy/samsung/phy-exynos5-usbdrd.c
@@ -8,6 +8,7 @@
* Author: Vivek Gautam <[email protected]>
*/

+#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
@@ -141,6 +142,9 @@
#define CLKRST_PORT_RST BIT(1)
#define CLKRST_LINK_SW_RST BIT(0)

+#define EXYNOS850_DRD_SSPPLLCTL 0x30
+#define SSPPLLCTL_FSEL GENMASK(2, 0)
+
#define EXYNOS850_DRD_UTMI 0x50
#define UTMI_FORCE_VBUSVALID BIT(5)
#define UTMI_FORCE_BVALID BIT(4)
@@ -773,6 +777,31 @@ static void exynos850_usbdrd_utmi_init(struct exynos5_usbdrd_phy *phy_drd)
reg |= HSP_VBUSVLDEXT | HSP_VBUSVLDEXTSEL;
writel(reg, regs_base + EXYNOS850_DRD_HSP);

+ reg = readl(regs_base + EXYNOS850_DRD_SSPPLLCTL);
+ reg &= ~SSPPLLCTL_FSEL;
+ switch (phy_drd->extrefclk) {
+ case EXYNOS5_FSEL_50MHZ:
+ reg |= FIELD_PREP_CONST(SSPPLLCTL_FSEL, 7);
+ break;
+ case EXYNOS5_FSEL_26MHZ:
+ reg |= FIELD_PREP_CONST(SSPPLLCTL_FSEL, 6);
+ break;
+ case EXYNOS5_FSEL_24MHZ:
+ reg |= FIELD_PREP_CONST(SSPPLLCTL_FSEL, 2);
+ break;
+ case EXYNOS5_FSEL_20MHZ:
+ reg |= FIELD_PREP_CONST(SSPPLLCTL_FSEL, 1);
+ break;
+ case EXYNOS5_FSEL_19MHZ2:
+ reg |= FIELD_PREP_CONST(SSPPLLCTL_FSEL, 0);
+ break;
+ default:
+ dev_warn(phy_drd->dev, "unsupported ref clk: %#.2x\n",
+ phy_drd->extrefclk);
+ break;
+ }
+ writel(reg, regs_base + EXYNOS850_DRD_SSPPLLCTL);
+
/* Power up PHY analog blocks */
reg = readl(regs_base + EXYNOS850_DRD_HSP_TEST);
reg &= ~HSP_TEST_SIDDQ;

--
2.45.0.rc1.225.g2a3ae87e7f-goog

2024-06-12 09:38:13

by Peter Griffin

Subject: Re: [PATCH 5/5] phy: exynos5-usbdrd: set ref clk freq in exynos850_usbdrd_utmi_init()

Hi André,

On Tue, 7 May 2024 at 15:14, André Draszik <[email protected]> wrote:
>
> While commit 255ec3879dd4 ("phy: exynos5-usbdrd: Add 26MHz ref clk
> support") correctly states that CLKRSTCTRL[7:5] doesn't need to be set
> on modern Exynos platforms, SSPPLLCTL[2:0] should be programmed with
> the frequency of the reference clock for the USB2.0 phy instead.
>
> I stumbled across this while adding support for the Google Tensor
> gs101, but this should apply to E850 just the same.
>
> Do so.
>
> Fixes: 691525074db9 ("phy: exynos5-usbdrd: Add Exynos850 support")
> Signed-off-by: André Draszik <[email protected]>
>
> ---
> Feel free to drop the Fixes: if you think that is unwarranted here.
>
> v2: add missing bitfield.h include (seems this is implied on some
> platforms, but not on others)
> ---

Reviewed-by: Peter Griffin <[email protected]>

regards,

Peter

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