[linux-sunxi] Re: [PATCH 1/3] phy-sun4i-usb: Add a sunxi specific function for setting squelch-detect

Hi Felipe,

On Monday 11 May 2015 11:43 PM, Hans de Goede wrote:

Hi,

On 11-05-15 17:55, Felipe Balbi wrote:

quoted

Hi,

On Sun, May 10, 2015 at 12:02:54PM +0200, Hans de Goede wrote:

quoted

Hi,

On 08-05-15 18:06, Felipe Balbi wrote:

quoted

Hi,

On Sun, Mar 29, 2015 at 12:50:46PM +0200, Hans de Goede wrote:

quoted

The sunxi otg phy has a bug where it wrongly detects a high speed squelch
when reset on the root port gets de-asserted with a lo-speed device.

The workaround for this is to disable squelch detect before de-asserting
reset, and re-enabling it after the reset de-assert is done. Add a sunxi
specific phy function to allow the sunxi-musb glue to do this.

Signed-off-by: Hans de Goede <redacted>
---
   drivers/phy/phy-sun4i-usb.c       |  9 +++++++++
   include/linux/phy/phy-sun4i-usb.h | 26 ++++++++++++++++++++++++++
   2 files changed, 35 insertions(+)
   create mode 100644 include/linux/phy/phy-sun4i-usb.h

diff --git a/drivers/phy/phy-sun4i-usb.c b/drivers/phy/phy-sun4i-usb.c
index 221e8ab..01eb08d 100644
--- a/drivers/phy/phy-sun4i-usb.c
+++ b/drivers/phy/phy-sun4i-usb.c

@@ -33,6 +33,7 @@
   #include <linux/of_address.h>
   #include <linux/of_gpio.h>
   #include <linux/phy/phy.h>
+#include <linux/phy/phy-sun4i-usb.h>
   #include <linux/platform_device.h>
   #include <linux/regulator/consumer.h>
   #include <linux/reset.h>

@@ -75,6 +76,7 @@
   #define PHY_OTG_FUNC_EN			0x28
   #define PHY_VBUS_DET_EN			0x29
   #define PHY_DISCON_TH_SEL		0x2a
+#define PHY_SQUELCH_DETECT		0x3c

   #define MAX_PHYS			3

@@ -322,6 +324,13 @@ static int sun4i_usb_phy_power_off(struct phy *_phy)
   	return 0;
   }

+void sun4i_usb_phy_set_squelch_detect(struct phy *_phy, bool enabled)
+{
+	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
+
+	sun4i_usb_phy_write(phy, PHY_SQUELCH_DETECT, enabled ? 0 : 2, 2);
+}
+
   static struct phy_ops sun4i_usb_phy_ops = {
   	.init		= sun4i_usb_phy_init,
   	.exit		= sun4i_usb_phy_exit,

diff --git a/include/linux/phy/phy-sun4i-usb.h b/include/linux/phy/phy-sun4i-usb.h
new file mode 100644
index 0000000..50aed92
--- /dev/null
+++ b/include/linux/phy/phy-sun4i-usb.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2015 Hans de Goede <hdegoede@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef PHY_SUN4I_USB_H_
+#define PHY_SUN4I_USB_H_
+
+#include "phy.h"
+
+/**
+ * sun4i_usb_phy_set_squelch_detect() - Enable/disable squelch detect
+ * @phy: reference to a sun4i usb phy
+ * @enabled: wether to enable or disable squelch detect
+ */
+void sun4i_usb_phy_set_squelch_detect(struct phy *phy, bool enabled);

breaks build if MUSB=y and SUN41_PHY=m

Ah, good one. So I assume that it is ok to fix this by doing:

--- a/drivers/usb/musb/Kconfig
+++ b/drivers/usb/musb/Kconfig

@@ -66,6 +66,7 @@ config USB_MUSB_SUNXI
          tristate "Allwinner (sunxi)"
          depends on ARCH_SUNXI
          depends on NOP_USB_XCEIV
+ depends on PHY_SUN4I_USB

I would prefer not exporting any function from phy to musb. Perhaps
figure out with Kishon how "set_squelch" can be added to PHY fwk ?

We don't want to be adding platform specific hooks in PHY framework. While 
exporting a function from PHY to MUSB is not the best thing, it's still okay 
since it is from musb sunxi glue only no?

Thanks
Kishon