[PATCH v3 0/4] USB: OMAP1: Tahvo USB support for 770

[PATCH v3 0/4] USB: OMAP1: Tahvo USB support for 770

[Aaro Koskinen]

Hi,

These patches add support for Tahvo USB transceiver and allow using both
host and peripheral modes on Nokia 770.

Tested (peripheral mode, host mode, vbus detection) with 3.10-rc6.

History:
	v3: Delete accidental #include <mach/usb.h> from patch 3.
	    Drop board file changes, already queued to linux-omap.
	v2: http://marc.info/?l=linux-omap&m=137138976406242&w=2
	    Use extcon framework to trigger OTG driver mode changes.
	v1: http://marc.info/?l=linux-omap&m=137081763029385&w=2

Earlier RFC versions:
	http://marc.info/?l=linux-omap&m=136553710000679&w=2
	http://marc.info/?l=linux-omap&m=136266725827698&w=2

Aaro Koskinen (4):
  ARM: OMAP1: USB: move omap_usb_config to platform data
  USB: OMAP1: add extcon to platform data
  USB: OMAP1: OTG controller driver
  USB: OMAP1: Tahvo USB transceiver driver

 arch/arm/mach-omap1/include/mach/usb.h  |  38 +--
 drivers/usb/phy/Kconfig                 |  24 ++
 drivers/usb/phy/Makefile                |   2 +
 drivers/usb/phy/phy-omap-otg.c          | 169 ++++++++++++
 drivers/usb/phy/phy-tahvo.c             | 448 ++++++++++++++++++++++++++++++++
 include/linux/platform_data/usb-omap1.h |  53 ++++
 6 files changed, 697 insertions(+), 37 deletions(-)
 create mode 100644 drivers/usb/phy/phy-omap-otg.c
 create mode 100644 drivers/usb/phy/phy-tahvo.c
 create mode 100644 include/linux/platform_data/usb-omap1.h

A.

-- 
1.8.3.1

[PATCH v3 1/4] ARM: OMAP1: USB: move omap_usb_config to platform data

[Aaro Koskinen]

Move omap_usb_config to platform data, so that OTG driver can include it.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mach-omap1/include/mach/usb.h  | 38 +-----------------------
 include/linux/platform_data/usb-omap1.h | 51 +++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 37 deletions(-)
 create mode 100644 include/linux/platform_data/usb-omap1.h

diff --git a/arch/arm/mach-omap1/include/mach/usb.h b/arch/arm/mach-omap1/include/mach/usb.h
index 45e5ac7..2c26305 100644
--- a/arch/arm/mach-omap1/include/mach/usb.h
+++ b/arch/arm/mach-omap1/include/mach/usb.h
@@ -8,43 +8,7 @@
 #define	is_usb0_device(config)	0
 #endif
 
-struct omap_usb_config {
-	/* Configure drivers according to the connectors on your board:
-	 *  - "A" connector (rectagular)
-	 *	... for host/OHCI use, set "register_host".
-	 *  - "B" connector (squarish) or "Mini-B"
-	 *	... for device/gadget use, set "register_dev".
-	 *  - "Mini-AB" connector (very similar to Mini-B)
-	 *	... for OTG use as device OR host, initialize "otg"
-	 */
-	unsigned	register_host:1;
-	unsigned	register_dev:1;
-	u8		otg;	/* port number, 1-based:  usb1 == 2 */
-
-	u8		hmc_mode;
-
-	/* implicitly true if otg:  host supports remote wakeup? */
-	u8		rwc;
-
-	/* signaling pins used to talk to transceiver on usbN:
-	 *  0 == usbN unused
-	 *  2 == usb0-only, using internal transceiver
-	 *  3 == 3 wire bidirectional
-	 *  4 == 4 wire bidirectional
-	 *  6 == 6 wire unidirectional (or TLL)
-	 */
-	u8		pins[3];
-
-	struct platform_device *udc_device;
-	struct platform_device *ohci_device;
-	struct platform_device *otg_device;
-
-	u32 (*usb0_init)(unsigned nwires, unsigned is_device);
-	u32 (*usb1_init)(unsigned nwires);
-	u32 (*usb2_init)(unsigned nwires, unsigned alt_pingroup);
-
-	int (*ocpi_enable)(void);
-};
+#include <linux/platform_data/usb-omap1.h>
 
 void omap_otg_init(struct omap_usb_config *config);
 
diff --git a/include/linux/platform_data/usb-omap1.h b/include/linux/platform_data/usb-omap1.h
new file mode 100644
index 0000000..8c7764d
--- /dev/null
+++ b/include/linux/platform_data/usb-omap1.h
@@ -0,0 +1,51 @@
+/*
+ * Platform data for OMAP1 USB
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive for
+ * more details.
+ */
+#ifndef __LINUX_USB_OMAP1_H
+#define __LINUX_USB_OMAP1_H
+
+#include <linux/platform_device.h>
+
+struct omap_usb_config {
+	/* Configure drivers according to the connectors on your board:
+	 *  - "A" connector (rectagular)
+	 *	... for host/OHCI use, set "register_host".
+	 *  - "B" connector (squarish) or "Mini-B"
+	 *	... for device/gadget use, set "register_dev".
+	 *  - "Mini-AB" connector (very similar to Mini-B)
+	 *	... for OTG use as device OR host, initialize "otg"
+	 */
+	unsigned	register_host:1;
+	unsigned	register_dev:1;
+	u8		otg;	/* port number, 1-based:  usb1 == 2 */
+
+	u8		hmc_mode;
+
+	/* implicitly true if otg:  host supports remote wakeup? */
+	u8		rwc;
+
+	/* signaling pins used to talk to transceiver on usbN:
+	 *  0 == usbN unused
+	 *  2 == usb0-only, using internal transceiver
+	 *  3 == 3 wire bidirectional
+	 *  4 == 4 wire bidirectional
+	 *  6 == 6 wire unidirectional (or TLL)
+	 */
+	u8		pins[3];
+
+	struct platform_device *udc_device;
+	struct platform_device *ohci_device;
+	struct platform_device *otg_device;
+
+	u32 (*usb0_init)(unsigned nwires, unsigned is_device);
+	u32 (*usb1_init)(unsigned nwires);
+	u32 (*usb2_init)(unsigned nwires, unsigned alt_pingroup);
+
+	int (*ocpi_enable)(void);
+};
+
+#endif /* __LINUX_USB_OMAP1_H */
-- 
1.8.3.1

[PATCH v3 2/4] USB: OMAP1: add extcon to platform data

[Aaro Koskinen]

Add extcon field to platform data.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
---
 include/linux/platform_data/usb-omap1.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/platform_data/usb-omap1.h b/include/linux/platform_data/usb-omap1.h
index 8c7764d..43b5ce1 100644
--- a/include/linux/platform_data/usb-omap1.h
+++ b/include/linux/platform_data/usb-omap1.h
@@ -23,6 +23,8 @@ struct omap_usb_config {
 	unsigned	register_dev:1;
 	u8		otg;	/* port number, 1-based:  usb1 == 2 */
 
+	const char	*extcon;	/* extcon device for OTG */
+
 	u8		hmc_mode;
 
 	/* implicitly true if otg:  host supports remote wakeup? */
-- 
1.8.3.1

[PATCH v3 3/4] USB: OMAP1: OTG controller driver

[Aaro Koskinen]

Transceivers need to manage OTG controller state on OMAP1 to enable
switching between peripheral and host modes. Provide a driver for that.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
---
 drivers/usb/phy/Kconfig        |  10 +++
 drivers/usb/phy/Makefile       |   1 +
 drivers/usb/phy/phy-omap-otg.c | 169 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 180 insertions(+)
 create mode 100644 drivers/usb/phy/phy-omap-otg.c

diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 7ef3eb8..14a50bd 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -135,6 +135,16 @@ config USB_GPIO_VBUS
 	  optionally control of a D+ pullup GPIO as well as a VBUS
 	  current limit regulator.
 
+config OMAP_OTG
+	tristate "OMAP USB OTG controller driver"
+	depends on ARCH_OMAP_OTG && EXTCON
+	help
+	  Enable this to support some transceivers on OMAP1 platforms. OTG
+	  controller is needed to switch between host and peripheral modes.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called omap-otg.
+
 config USB_ISP1301
 	tristate "NXP ISP1301 USB transceiver support"
 	depends on USB || USB_GADGET
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index a9169cb..c7f391b 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_ISP1301_OMAP)		+= phy-isp1301-omap.o
 obj-$(CONFIG_MV_U3D_PHY)		+= phy-mv-u3d-usb.o
 obj-$(CONFIG_NOP_USB_XCEIV)		+= phy-nop.o
 obj-$(CONFIG_OMAP_CONTROL_USB)		+= phy-omap-control.o
+obj-$(CONFIG_OMAP_OTG)			+= phy-omap-otg.o
 obj-$(CONFIG_OMAP_USB2)			+= phy-omap-usb2.o
 obj-$(CONFIG_OMAP_USB3)			+= phy-omap-usb3.o
 obj-$(CONFIG_SAMSUNG_USBPHY)		+= phy-samsung-usb.o
diff --git a/drivers/usb/phy/phy-omap-otg.c b/drivers/usb/phy/phy-omap-otg.c
new file mode 100644
index 0000000..11598cd
--- /dev/null
+++ b/drivers/usb/phy/phy-omap-otg.c
@@ -0,0 +1,169 @@
+/*
+ * OMAP OTG controller driver
+ *
+ * Based on code from tahvo-usb.c and isp1301_omap.c drivers.
+ *
+ * Copyright (C) 2005-2006 Nokia Corporation
+ * Copyright (C) 2004 Texas Instruments
+ * Copyright (C) 2004 David Brownell
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * 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.
+ */
+
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/extcon.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/usb-omap1.h>
+
+struct otg_device {
+	void __iomem			*base;
+	bool				id;
+	bool				vbus;
+	struct extcon_specific_cable_nb	vbus_dev;
+	struct extcon_specific_cable_nb	id_dev;
+	struct notifier_block		vbus_nb;
+	struct notifier_block		id_nb;
+};
+
+#define OMAP_OTG_CTRL		0x0c
+#define OMAP_OTG_ASESSVLD	(1 << 20)
+#define OMAP_OTG_BSESSEND	(1 << 19)
+#define OMAP_OTG_BSESSVLD	(1 << 18)
+#define OMAP_OTG_VBUSVLD	(1 << 17)
+#define OMAP_OTG_ID		(1 << 16)
+#define OMAP_OTG_XCEIV_OUTPUTS \
+	(OMAP_OTG_ASESSVLD | OMAP_OTG_BSESSEND | OMAP_OTG_BSESSVLD | \
+	 OMAP_OTG_VBUSVLD  | OMAP_OTG_ID)
+
+static void omap_otg_ctrl(struct otg_device *otg_dev, u32 outputs)
+{
+	u32 l;
+
+	l = readl(otg_dev->base + OMAP_OTG_CTRL);
+	l &= ~OMAP_OTG_XCEIV_OUTPUTS;
+	l |= outputs;
+	writel(l, otg_dev->base + OMAP_OTG_CTRL);
+}
+
+static void omap_otg_set_mode(struct otg_device *otg_dev)
+{
+	if (!otg_dev->id && otg_dev->vbus)
+		/* Set B-session valid. */
+		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSVLD);
+	else if (otg_dev->vbus)
+		/* Set A-session valid. */
+		omap_otg_ctrl(otg_dev, OMAP_OTG_ASESSVLD);
+	else if (!otg_dev->id)
+		/* Set B-session end to indicate no VBUS. */
+		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSEND);
+}
+
+static int omap_otg_id_notifier(struct notifier_block *nb,
+				unsigned long event, void *ptr)
+{
+	struct otg_device *otg_dev = container_of(nb, struct otg_device, id_nb);
+
+	otg_dev->id = event;
+	omap_otg_set_mode(otg_dev);
+
+	return NOTIFY_DONE;
+}
+
+static int omap_otg_vbus_notifier(struct notifier_block *nb,
+				  unsigned long event, void *ptr)
+{
+	struct otg_device *otg_dev = container_of(nb, struct otg_device,
+						  vbus_nb);
+
+	otg_dev->vbus = event;
+	omap_otg_set_mode(otg_dev);
+
+	return NOTIFY_DONE;
+}
+
+static int omap_otg_probe(struct platform_device *pdev)
+{
+	const struct omap_usb_config *config = pdev->dev.platform_data;
+	struct otg_device *otg_dev;
+	struct extcon_dev *extcon;
+	int ret;
+	u32 rev;
+
+	if (!config || !config->extcon)
+		return -ENODEV;
+
+	extcon = extcon_get_extcon_dev(config->extcon);
+	if (!extcon)
+		return -EPROBE_DEFER;
+
+	otg_dev = devm_kzalloc(&pdev->dev, sizeof(*otg_dev), GFP_KERNEL);
+	if (!otg_dev)
+		return -ENOMEM;
+
+	otg_dev->base = devm_ioremap_resource(&pdev->dev, &pdev->resource[0]);
+	if (IS_ERR(otg_dev->base))
+		return PTR_ERR(otg_dev->base);
+
+	otg_dev->id_nb.notifier_call = omap_otg_id_notifier;
+	otg_dev->vbus_nb.notifier_call = omap_otg_vbus_notifier;
+
+	ret = extcon_register_interest(&otg_dev->id_dev, config->extcon,
+				       "USB-HOST", &otg_dev->id_nb);
+	if (ret)
+		return ret;
+
+	ret = extcon_register_interest(&otg_dev->vbus_dev, config->extcon,
+				       "USB", &otg_dev->vbus_nb);
+	if (ret) {
+		extcon_unregister_interest(&otg_dev->id_dev);
+		return ret;
+	}
+
+	otg_dev->id = extcon_get_cable_state(extcon, "USB-HOST");
+	otg_dev->vbus = extcon_get_cable_state(extcon, "USB");
+	omap_otg_set_mode(otg_dev);
+
+	rev = readl(otg_dev->base);
+
+	dev_info(&pdev->dev,
+		 "OMAP USB OTG controller rev %d.%d (%s, id=%d, vbus=%d)\n",
+		 (rev >> 4) & 0xf, rev & 0xf, config->extcon, otg_dev->id,
+		 otg_dev->vbus);
+
+	return 0;
+}
+
+static int omap_otg_remove(struct platform_device *pdev)
+{
+	struct otg_device *otg_dev = platform_get_drvdata(pdev);
+
+	extcon_unregister_interest(&otg_dev->id_dev);
+	extcon_unregister_interest(&otg_dev->vbus_dev);
+
+	return 0;
+}
+
+static struct platform_driver omap_otg_driver = {
+	.probe		= omap_otg_probe,
+	.remove		= omap_otg_remove,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "omap_otg",
+	},
+};
+module_platform_driver(omap_otg_driver);
+
+MODULE_DESCRIPTION("OMAP USB OTG controller driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
-- 
1.8.3.1

[PATCH v3 4/4] USB: OMAP1: Tahvo USB transceiver driver

[Aaro Koskinen]

Add Tahvo USB transceiver driver.

Based on old code from linux-omap tree. The original driver was written
by Juha Yrj?l?, Tony Lindgren, and Timo Ter?s.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
---
 drivers/usb/phy/Kconfig     |  14 ++
 drivers/usb/phy/Makefile    |   1 +
 drivers/usb/phy/phy-tahvo.c | 448 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 463 insertions(+)
 create mode 100644 drivers/usb/phy/phy-tahvo.c

diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 14a50bd..a5c7937 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -145,6 +145,20 @@ config OMAP_OTG
 	  This driver can also be built as a module. If so, the module
 	  will be called omap-otg.
 
+config TAHVO_USB
+	tristate "Tahvo USB transceiver driver"
+	depends on MFD_RETU && EXTCON
+	help
+	  Enable this to support USB transceiver on Tahvo. This is used
+	  at least on Nokia 770.
+
+config TAHVO_USB_HOST_BY_DEFAULT
+	depends on TAHVO_USB
+	boolean "Device in USB host mode by default"
+	help
+	  Say Y here, if you want the device to enter USB host mode
+	  by default on bootup.
+
 config USB_ISP1301
 	tristate "NXP ISP1301 USB transceiver support"
 	depends on USB || USB_GADGET
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index c7f391b..f3984d1 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -13,6 +13,7 @@ phy-fsl-usb2-objs			:= phy-fsl-usb.o phy-fsm-usb.o
 obj-$(CONFIG_FSL_USB2_OTG)		+= phy-fsl-usb2.o
 obj-$(CONFIG_ISP1301_OMAP)		+= phy-isp1301-omap.o
 obj-$(CONFIG_MV_U3D_PHY)		+= phy-mv-u3d-usb.o
+obj-$(CONFIG_TAHVO_USB)			+= phy-tahvo.o
 obj-$(CONFIG_NOP_USB_XCEIV)		+= phy-nop.o
 obj-$(CONFIG_OMAP_CONTROL_USB)		+= phy-omap-control.o
 obj-$(CONFIG_OMAP_OTG)			+= phy-omap-otg.o
diff --git a/drivers/usb/phy/phy-tahvo.c b/drivers/usb/phy/phy-tahvo.c
new file mode 100644
index 0000000..a2d96a2
--- /dev/null
+++ b/drivers/usb/phy/phy-tahvo.c
@@ -0,0 +1,448 @@
+/*
+ * Tahvo USB transceiver driver
+ *
+ * Copyright (C) 2005-2006 Nokia Corporation
+ *
+ * Parts copied from isp1301_omap.c.
+ * Copyright (C) 2004 Texas Instruments
+ * Copyright (C) 2004 David Brownell
+ *
+ * Original driver written by Juha Yrj?l?, Tony Lindgren and Timo Ter?s.
+ * Modified for Retu/Tahvo MFD by Aaro Koskinen.
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * 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.
+ */
+
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/usb.h>
+#include <linux/extcon.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/usb/otg.h>
+#include <linux/mfd/retu.h>
+#include <linux/usb/gadget.h>
+#include <linux/platform_device.h>
+
+#define DRIVER_NAME     "tahvo-usb"
+
+#define TAHVO_REG_IDSR	0x02
+#define TAHVO_REG_USBR	0x06
+
+#define USBR_SLAVE_CONTROL	(1 << 8)
+#define USBR_VPPVIO_SW		(1 << 7)
+#define USBR_SPEED		(1 << 6)
+#define USBR_REGOUT		(1 << 5)
+#define USBR_MASTER_SW2		(1 << 4)
+#define USBR_MASTER_SW1		(1 << 3)
+#define USBR_SLAVE_SW		(1 << 2)
+#define USBR_NSUSPEND		(1 << 1)
+#define USBR_SEMODE		(1 << 0)
+
+#define TAHVO_MODE_HOST		0
+#define TAHVO_MODE_PERIPHERAL	1
+
+struct tahvo_usb {
+	struct platform_device	*pt_dev;
+	struct usb_phy		phy;
+	int			vbus_state;
+	struct mutex		serialize;
+	struct clk		*ick;
+	int			irq;
+	int			tahvo_mode;
+	struct extcon_dev	extcon;
+};
+
+static const char *tahvo_cable[] = {
+	"USB-HOST",
+	"USB",
+	NULL,
+};
+
+static ssize_t vbus_state_show(struct device *device,
+			       struct device_attribute *attr, char *buf)
+{
+	struct tahvo_usb *tu = dev_get_drvdata(device);
+	return sprintf(buf, "%d\n", tu->vbus_state);
+}
+static DEVICE_ATTR(vbus_state, 0444, vbus_state_show, NULL);
+
+static void check_vbus_state(struct tahvo_usb *tu)
+{
+	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
+	int reg, prev_state;
+
+	reg = retu_read(rdev, TAHVO_REG_IDSR);
+	if (reg & TAHVO_STAT_VBUS) {
+		switch (tu->phy.state) {
+		case OTG_STATE_B_IDLE:
+			/* Enable the gadget driver */
+			if (tu->phy.otg->gadget)
+				usb_gadget_vbus_connect(tu->phy.otg->gadget);
+			tu->phy.state = OTG_STATE_B_PERIPHERAL;
+			break;
+		case OTG_STATE_A_IDLE:
+			/*
+			 * Session is now valid assuming the USB hub is driving
+			 * Vbus.
+			 */
+			tu->phy.state = OTG_STATE_A_HOST;
+			break;
+		default:
+			break;
+		}
+		dev_info(&tu->pt_dev->dev, "USB cable connected\n");
+	} else {
+		switch (tu->phy.state) {
+		case OTG_STATE_B_PERIPHERAL:
+			if (tu->phy.otg->gadget)
+				usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
+			tu->phy.state = OTG_STATE_B_IDLE;
+			break;
+		case OTG_STATE_A_HOST:
+			tu->phy.state = OTG_STATE_A_IDLE;
+			break;
+		default:
+			break;
+		}
+		dev_info(&tu->pt_dev->dev, "USB cable disconnected\n");
+	}
+
+	prev_state = tu->vbus_state;
+	tu->vbus_state = reg & TAHVO_STAT_VBUS;
+	if (prev_state != tu->vbus_state) {
+		extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
+		sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state");
+	}
+}
+
+static void tahvo_usb_become_host(struct tahvo_usb *tu)
+{
+	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
+
+	extcon_set_cable_state(&tu->extcon, "USB-HOST", true);
+
+	/* Power up the transceiver in USB host mode */
+	retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
+		   USBR_MASTER_SW2 | USBR_MASTER_SW1);
+	tu->phy.state = OTG_STATE_A_IDLE;
+
+	check_vbus_state(tu);
+}
+
+static void tahvo_usb_stop_host(struct tahvo_usb *tu)
+{
+	tu->phy.state = OTG_STATE_A_IDLE;
+}
+
+static void tahvo_usb_become_peripheral(struct tahvo_usb *tu)
+{
+	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
+
+	extcon_set_cable_state(&tu->extcon, "USB-HOST", false);
+
+	/* Power up transceiver and set it in USB peripheral mode */
+	retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT |
+		   USBR_NSUSPEND | USBR_SLAVE_SW);
+	tu->phy.state = OTG_STATE_B_IDLE;
+
+	check_vbus_state(tu);
+}
+
+static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu)
+{
+	if (tu->phy.otg->gadget)
+		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
+	tu->phy.state = OTG_STATE_B_IDLE;
+}
+
+static void tahvo_usb_power_off(struct tahvo_usb *tu)
+{
+	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
+
+	/* Disable gadget controller if any */
+	if (tu->phy.otg->gadget)
+		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
+
+	/* Power off transceiver */
+	retu_write(rdev, TAHVO_REG_USBR, 0);
+	tu->phy.state = OTG_STATE_UNDEFINED;
+}
+
+static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend)
+{
+	struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy);
+	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
+	u16 w;
+
+	dev_dbg(&tu->pt_dev->dev, "%s\n", __func__);
+
+	w = retu_read(rdev, TAHVO_REG_USBR);
+	if (suspend)
+		w &= ~USBR_NSUSPEND;
+	else
+		w |= USBR_NSUSPEND;
+	retu_write(rdev, TAHVO_REG_USBR, w);
+
+	return 0;
+}
+
+static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
+{
+	struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
+
+	dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
+
+	if (otg == NULL)
+		return -ENODEV;
+
+	mutex_lock(&tu->serialize);
+
+	if (host == NULL) {
+		if (tu->tahvo_mode == TAHVO_MODE_HOST)
+			tahvo_usb_power_off(tu);
+		otg->host = NULL;
+		mutex_unlock(&tu->serialize);
+		return 0;
+	}
+
+	if (tu->tahvo_mode == TAHVO_MODE_HOST) {
+		otg->host = NULL;
+		tahvo_usb_become_host(tu);
+	}
+
+	otg->host = host;
+
+	mutex_unlock(&tu->serialize);
+
+	return 0;
+}
+
+static int tahvo_usb_set_peripheral(struct usb_otg *otg,
+				    struct usb_gadget *gadget)
+{
+	struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
+
+	dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget);
+
+	if (!otg)
+		return -ENODEV;
+
+	mutex_lock(&tu->serialize);
+
+	if (!gadget) {
+		if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
+			tahvo_usb_power_off(tu);
+		tu->phy.otg->gadget = NULL;
+		mutex_unlock(&tu->serialize);
+		return 0;
+	}
+
+	tu->phy.otg->gadget = gadget;
+	if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
+		tahvo_usb_become_peripheral(tu);
+
+	mutex_unlock(&tu->serialize);
+
+	return 0;
+}
+
+static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu)
+{
+	struct tahvo_usb *tu = _tu;
+
+	mutex_lock(&tu->serialize);
+	check_vbus_state(tu);
+	mutex_unlock(&tu->serialize);
+
+	return IRQ_HANDLED;
+}
+
+static ssize_t otg_mode_show(struct device *device,
+			     struct device_attribute *attr, char *buf)
+{
+	struct tahvo_usb *tu = dev_get_drvdata(device);
+
+	switch (tu->tahvo_mode) {
+	case TAHVO_MODE_HOST:
+		return sprintf(buf, "host\n");
+	case TAHVO_MODE_PERIPHERAL:
+		return sprintf(buf, "peripheral\n");
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t otg_mode_store(struct device *device,
+			      struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct tahvo_usb *tu = dev_get_drvdata(device);
+	int r;
+
+	mutex_lock(&tu->serialize);
+	if (count >= 4 && strncmp(buf, "host", 4) == 0) {
+		if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
+			tahvo_usb_stop_peripheral(tu);
+		tu->tahvo_mode = TAHVO_MODE_HOST;
+		if (tu->phy.otg->host) {
+			dev_info(device, "HOST mode: host controller present\n");
+			tahvo_usb_become_host(tu);
+		} else {
+			dev_info(device, "HOST mode: no host controller, powering off\n");
+			tahvo_usb_power_off(tu);
+		}
+		r = strlen(buf);
+	} else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
+		if (tu->tahvo_mode == TAHVO_MODE_HOST)
+			tahvo_usb_stop_host(tu);
+		tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
+		if (tu->phy.otg->gadget) {
+			dev_info(device, "PERIPHERAL mode: gadget driver present\n");
+			tahvo_usb_become_peripheral(tu);
+		} else {
+			dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
+			tahvo_usb_power_off(tu);
+		}
+		r = strlen(buf);
+	} else {
+		r = -EINVAL;
+	}
+	mutex_unlock(&tu->serialize);
+
+	return r;
+}
+
+static DEVICE_ATTR(otg_mode, 0644, otg_mode_show, otg_mode_store);
+
+static int tahvo_usb_probe(struct platform_device *pdev)
+{
+	struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
+	struct tahvo_usb *tu;
+	int ret;
+
+	tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
+	if (!tu)
+		return -ENOMEM;
+
+	tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
+				   GFP_KERNEL);
+	if (!tu->phy.otg)
+		return -ENOMEM;
+
+	tu->pt_dev = pdev;
+
+	/* Default mode */
+#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
+	tu->tahvo_mode = TAHVO_MODE_HOST;
+#else
+	tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
+#endif
+
+	mutex_init(&tu->serialize);
+
+	tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
+	if (!IS_ERR(tu->ick))
+		clk_enable(tu->ick);
+
+	/*
+	 * Set initial state, so that we generate kevents only on state changes.
+	 */
+	tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
+
+	tu->extcon.name = DRIVER_NAME;
+	tu->extcon.supported_cable = tahvo_cable;
+	ret = extcon_dev_register(&tu->extcon, &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "could not register extcon device: %d\n",
+			ret);
+		return ret;
+	}
+
+	/* Set the initial cable state. */
+	extcon_set_cable_state(&tu->extcon, "USB-HOST",
+			       tu->tahvo_mode == TAHVO_MODE_HOST);
+	extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
+
+	tu->irq = platform_get_irq(pdev, 0);
+	ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt, 0,
+				   "tahvo-vbus", tu);
+	if (ret) {
+		dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
+			ret);
+		goto err_disable_clk;
+	}
+
+	/* Attributes */
+	ret = device_create_file(&pdev->dev, &dev_attr_vbus_state);
+	ret |= device_create_file(&pdev->dev, &dev_attr_otg_mode);
+	if (ret)
+		dev_err(&pdev->dev, "attribute creation failed: %d\n", ret);
+
+	/* Create OTG interface */
+	tahvo_usb_power_off(tu);
+	tu->phy.dev = &pdev->dev;
+	tu->phy.state = OTG_STATE_UNDEFINED;
+	tu->phy.label = DRIVER_NAME;
+	tu->phy.set_suspend = tahvo_usb_set_suspend;
+
+	tu->phy.otg->phy = &tu->phy;
+	tu->phy.otg->set_host = tahvo_usb_set_host;
+	tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral;
+
+	ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "cannot register USB transceiver: %d\n",
+			ret);
+		goto err_free_irq;
+	}
+
+	dev_set_drvdata(&pdev->dev, tu);
+
+	return 0;
+
+err_free_irq:
+	free_irq(tu->irq, tu);
+err_disable_clk:
+	if (!IS_ERR(tu->ick))
+		clk_disable(tu->ick);
+
+	return ret;
+}
+
+static int tahvo_usb_remove(struct platform_device *pdev)
+{
+	struct tahvo_usb *tu = platform_get_drvdata(pdev);
+
+	free_irq(tu->irq, tu);
+	usb_remove_phy(&tu->phy);
+	device_remove_file(&pdev->dev, &dev_attr_vbus_state);
+	device_remove_file(&pdev->dev, &dev_attr_otg_mode);
+	extcon_dev_unregister(&tu->extcon);
+	if (!IS_ERR(tu->ick))
+		clk_disable(tu->ick);
+
+	return 0;
+}
+
+static struct platform_driver tahvo_usb_driver = {
+	.probe		= tahvo_usb_probe,
+	.remove		= tahvo_usb_remove,
+	.driver		= {
+		.name	= "tahvo-usb",
+		.owner	= THIS_MODULE,
+	},
+};
+module_platform_driver(tahvo_usb_driver);
+
+MODULE_DESCRIPTION("Tahvo USB transceiver driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Juha Yrj?l?, Tony Lindgren, and Timo Ter?s");
+MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
-- 
1.8.3.1

[PATCH v3 4/4] USB: OMAP1: Tahvo USB transceiver driver

[Felipe Balbi]

Hi,

On Tue, Jun 18, 2013 at 08:07:01PM +0300, Aaro Koskinen wrote:
> +static ssize_t vbus_state_show(struct device *device,
> +			       struct device_attribute *attr, char *buf)
> +{
> +	struct tahvo_usb *tu = dev_get_drvdata(device);
> +	return sprintf(buf, "%d\n", tu->vbus_state);
> +}
> +static DEVICE_ATTR(vbus_state, 0444, vbus_state_show, NULL);

VBUS status sounds generic enough, also, you should be printing on/off
here instead of tahvo-specific values. Some users might not have access
to the docs, or even the kernel sources, to understand what that integer
means.

> +static void tahvo_usb_become_host(struct tahvo_usb *tu)
> +{
> +	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
> +
> +	extcon_set_cable_state(&tu->extcon, "USB-HOST", true);
> +
> +	/* Power up the transceiver in USB host mode */
> +	retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
> +		   USBR_MASTER_SW2 | USBR_MASTER_SW1);
> +	tu->phy.state = OTG_STATE_A_IDLE;
> +
> +	check_vbus_state(tu);
> +}
> +
> +static void tahvo_usb_stop_host(struct tahvo_usb *tu)
> +{
> +	tu->phy.state = OTG_STATE_A_IDLE;

shouldn't you undo tahvo_usb_become_host() here ? I mean, set the
transceiver to SLAVE ?

> +static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
> +{
> +	struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
> +
> +	dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
> +
> +	if (otg == NULL)
> +		return -ENODEV;
> +
> +	mutex_lock(&tu->serialize);
> +
> +	if (host == NULL) {
> +		if (tu->tahvo_mode == TAHVO_MODE_HOST)
> +			tahvo_usb_power_off(tu);
> +		otg->host = NULL;
> +		mutex_unlock(&tu->serialize);
> +		return 0;
> +	}
> +
> +	if (tu->tahvo_mode == TAHVO_MODE_HOST) {
> +		otg->host = NULL;
> +		tahvo_usb_become_host(tu);
> +	}
> +
> +	otg->host = host;
> +
> +	mutex_unlock(&tu->serialize);
> +
> +	return 0;
> +}
> +
> +static int tahvo_usb_set_peripheral(struct usb_otg *otg,
> +				    struct usb_gadget *gadget)

I want to get rid of the extra 'gadget' and 'host' parameters on
->set_host() and ->set_peripheral(). Nobody really uses them other than:

my_phy->phy.otg->{gadget,host} = {gadget,host};

For that, I need all other PHYs to stop relying on those parameters and
I'll cook patches for that for v3.12 merge window.

> +static ssize_t otg_mode_store(struct device *device,
> +			      struct device_attribute *attr,
> +			      const char *buf, size_t count)
> +{
> +	struct tahvo_usb *tu = dev_get_drvdata(device);
> +	int r;
> +
> +	mutex_lock(&tu->serialize);
> +	if (count >= 4 && strncmp(buf, "host", 4) == 0) {
> +		if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
> +			tahvo_usb_stop_peripheral(tu);
> +		tu->tahvo_mode = TAHVO_MODE_HOST;
> +		if (tu->phy.otg->host) {
> +			dev_info(device, "HOST mode: host controller present\n");
> +			tahvo_usb_become_host(tu);
> +		} else {
> +			dev_info(device, "HOST mode: no host controller, powering off\n");
> +			tahvo_usb_power_off(tu);
> +		}
> +		r = strlen(buf);
> +	} else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
> +		if (tu->tahvo_mode == TAHVO_MODE_HOST)
> +			tahvo_usb_stop_host(tu);
> +		tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
> +		if (tu->phy.otg->gadget) {
> +			dev_info(device, "PERIPHERAL mode: gadget driver present\n");
> +			tahvo_usb_become_peripheral(tu);
> +		} else {
> +			dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
> +			tahvo_usb_power_off(tu);
> +		}
> +		r = strlen(buf);
> +	} else {
> +		r = -EINVAL;
> +	}
> +	mutex_unlock(&tu->serialize);
> +
> +	return r;
> +}
> +
> +static DEVICE_ATTR(otg_mode, 0644, otg_mode_show, otg_mode_store);

this looks like something which would be very nice if implemented
generically. Since you, anyway miss the documentation in
Documentation/ABI/ and need to respin the patch, how about making this
generic ?

> +static int tahvo_usb_probe(struct platform_device *pdev)
> +{
> +	struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
> +	struct tahvo_usb *tu;
> +	int ret;
> +
> +	tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
> +	if (!tu)
> +		return -ENOMEM;
> +
> +	tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
> +				   GFP_KERNEL);
> +	if (!tu->phy.otg)
> +		return -ENOMEM;
> +
> +	tu->pt_dev = pdev;
> +
> +	/* Default mode */
> +#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
> +	tu->tahvo_mode = TAHVO_MODE_HOST;
> +#else
> +	tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
> +#endif

should you call become_host()/become_peripheral() here ?

> +	mutex_init(&tu->serialize);
> +
> +	tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
> +	if (!IS_ERR(tu->ick))
> +		clk_enable(tu->ick);
> +
> +	/*
> +	 * Set initial state, so that we generate kevents only on state changes.
> +	 */
> +	tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
> +
> +	tu->extcon.name = DRIVER_NAME;
> +	tu->extcon.supported_cable = tahvo_cable;
> +	ret = extcon_dev_register(&tu->extcon, &pdev->dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "could not register extcon device: %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	/* Set the initial cable state. */
> +	extcon_set_cable_state(&tu->extcon, "USB-HOST",
> +			       tu->tahvo_mode == TAHVO_MODE_HOST);
> +	extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
> +
> +	tu->irq = platform_get_irq(pdev, 0);
> +	ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt, 0,
> +				   "tahvo-vbus", tu);

since your hardirq handler is NULL, you *must* pass IRQF_ONESHOT. /Could
also use devm_request_threaded_irq()

> +	if (ret) {
> +		dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
> +			ret);
> +		goto err_disable_clk;
> +	}
> +
> +	/* Attributes */
> +	ret = device_create_file(&pdev->dev, &dev_attr_vbus_state);
> +	ret |= device_create_file(&pdev->dev, &dev_attr_otg_mode);

heh, Greg wrote a very interesting article recently (look at his blog)
discussing kernel/userland races wrt creation of sysfs files.

> +	/* Create OTG interface */
> +	tahvo_usb_power_off(tu);
> +	tu->phy.dev = &pdev->dev;
> +	tu->phy.state = OTG_STATE_UNDEFINED;
> +	tu->phy.label = DRIVER_NAME;
> +	tu->phy.set_suspend = tahvo_usb_set_suspend;
> +
> +	tu->phy.otg->phy = &tu->phy;
> +	tu->phy.otg->set_host = tahvo_usb_set_host;
> +	tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral;
> +
> +	ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "cannot register USB transceiver: %d\n",
> +			ret);
> +		goto err_free_irq;
> +	}
> +
> +	dev_set_drvdata(&pdev->dev, tu);

what if someone accesses the sysfs file you've already created before
you call dev_set_drvdata? (not sure  if it's possible).

-- 
balbi
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[PATCH v3 4/4] USB: OMAP1: Tahvo USB transceiver driver

[Aaro Koskinen]

Hi,

On Mon, Jul 08, 2013 at 10:21:09AM +0300, Felipe Balbi wrote:
> On Tue, Jun 18, 2013 at 08:07:01PM +0300, Aaro Koskinen wrote:
> > +static ssize_t vbus_state_show(struct device *device,
> > +			       struct device_attribute *attr, char *buf)
> > +{
> > +	struct tahvo_usb *tu = dev_get_drvdata(device);
> > +	return sprintf(buf, "%d\n", tu->vbus_state);
> > +}
> > +static DEVICE_ATTR(vbus_state, 0444, vbus_state_show, NULL);
> 
> VBUS status sounds generic enough, also, you should be printing on/off
> here instead of tahvo-specific values. Some users might not have access
> to the docs, or even the kernel sources, to understand what that integer
> means.

Ok, I'll fix.

> > +static void tahvo_usb_become_host(struct tahvo_usb *tu)
> > +{
> > +	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
> > +
> > +	extcon_set_cable_state(&tu->extcon, "USB-HOST", true);
> > +
> > +	/* Power up the transceiver in USB host mode */
> > +	retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
> > +		   USBR_MASTER_SW2 | USBR_MASTER_SW1);
> > +	tu->phy.state = OTG_STATE_A_IDLE;
> > +
> > +	check_vbus_state(tu);
> > +}
> > +
> > +static void tahvo_usb_stop_host(struct tahvo_usb *tu)
> > +{
> > +	tu->phy.state = OTG_STATE_A_IDLE;
> 
> shouldn't you undo tahvo_usb_become_host() here ? I mean, set the
> transceiver to SLAVE ?

tahvo_usb_become_peripheral() (or power_off) is always called after this
function. Actually, these stop functions can be eliminated altogether
as they are only called from a single place...

> > +static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
> > +{
> > +	struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
> > +
> > +	dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
> > +
> > +	if (otg == NULL)
> > +		return -ENODEV;
> > +
> > +	mutex_lock(&tu->serialize);
> > +
> > +	if (host == NULL) {
> > +		if (tu->tahvo_mode == TAHVO_MODE_HOST)
> > +			tahvo_usb_power_off(tu);
> > +		otg->host = NULL;
> > +		mutex_unlock(&tu->serialize);
> > +		return 0;
> > +	}
> > +
> > +	if (tu->tahvo_mode == TAHVO_MODE_HOST) {
> > +		otg->host = NULL;
> > +		tahvo_usb_become_host(tu);
> > +	}
> > +
> > +	otg->host = host;
> > +
> > +	mutex_unlock(&tu->serialize);
> > +
> > +	return 0;
> > +}
> > +
> > +static int tahvo_usb_set_peripheral(struct usb_otg *otg,
> > +				    struct usb_gadget *gadget)
> 
> I want to get rid of the extra 'gadget' and 'host' parameters on
> ->set_host() and ->set_peripheral(). Nobody really uses them other than:
> 
> my_phy->phy.otg->{gadget,host} = {gadget,host};
> 
> For that, I need all other PHYs to stop relying on those parameters and
> I'll cook patches for that for v3.12 merge window.

How will the PHY know if there is a host/gadget driver present? I guess
I will need to wait for those patches...

> > +static ssize_t otg_mode_store(struct device *device,
> > +			      struct device_attribute *attr,
> > +			      const char *buf, size_t count)
> > +{
> > +	struct tahvo_usb *tu = dev_get_drvdata(device);
> > +	int r;
> > +
> > +	mutex_lock(&tu->serialize);
> > +	if (count >= 4 && strncmp(buf, "host", 4) == 0) {
> > +		if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
> > +			tahvo_usb_stop_peripheral(tu);
> > +		tu->tahvo_mode = TAHVO_MODE_HOST;
> > +		if (tu->phy.otg->host) {
> > +			dev_info(device, "HOST mode: host controller present\n");
> > +			tahvo_usb_become_host(tu);
> > +		} else {
> > +			dev_info(device, "HOST mode: no host controller, powering off\n");
> > +			tahvo_usb_power_off(tu);
> > +		}
> > +		r = strlen(buf);
> > +	} else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
> > +		if (tu->tahvo_mode == TAHVO_MODE_HOST)
> > +			tahvo_usb_stop_host(tu);
> > +		tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
> > +		if (tu->phy.otg->gadget) {
> > +			dev_info(device, "PERIPHERAL mode: gadget driver present\n");
> > +			tahvo_usb_become_peripheral(tu);
> > +		} else {
> > +			dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
> > +			tahvo_usb_power_off(tu);
> > +		}
> > +		r = strlen(buf);
> > +	} else {
> > +		r = -EINVAL;
> > +	}
> > +	mutex_unlock(&tu->serialize);
> > +
> > +	return r;
> > +}
> > +
> > +static DEVICE_ATTR(otg_mode, 0644, otg_mode_show, otg_mode_store);
> 
> this looks like something which would be very nice if implemented
> generically. Since you, anyway miss the documentation in
> Documentation/ABI/ and need to respin the patch, how about making this
> generic ?

Ok, I'll try to come up with something...

> > +static int tahvo_usb_probe(struct platform_device *pdev)
> > +{
> > +	struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
> > +	struct tahvo_usb *tu;
> > +	int ret;
> > +
> > +	tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
> > +	if (!tu)
> > +		return -ENOMEM;
> > +
> > +	tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
> > +				   GFP_KERNEL);
> > +	if (!tu->phy.otg)
> > +		return -ENOMEM;
> > +
> > +	tu->pt_dev = pdev;
> > +
> > +	/* Default mode */
> > +#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
> > +	tu->tahvo_mode = TAHVO_MODE_HOST;
> > +#else
> > +	tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
> > +#endif
> 
> should you call become_host()/become_peripheral() here ?

Not needed. Once the PHY is registered, the framework will call set_host /
set_peripheral and the HW gets set to correct state.

> > +	mutex_init(&tu->serialize);
> > +
> > +	tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
> > +	if (!IS_ERR(tu->ick))
> > +		clk_enable(tu->ick);
> > +
> > +	/*
> > +	 * Set initial state, so that we generate kevents only on state changes.
> > +	 */
> > +	tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
> > +
> > +	tu->extcon.name = DRIVER_NAME;
> > +	tu->extcon.supported_cable = tahvo_cable;
> > +	ret = extcon_dev_register(&tu->extcon, &pdev->dev);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "could not register extcon device: %d\n",
> > +			ret);
> > +		return ret;
> > +	}
> > +
> > +	/* Set the initial cable state. */
> > +	extcon_set_cable_state(&tu->extcon, "USB-HOST",
> > +			       tu->tahvo_mode == TAHVO_MODE_HOST);
> > +	extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
> > +
> > +	tu->irq = platform_get_irq(pdev, 0);
> > +	ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt, 0,
> > +				   "tahvo-vbus", tu);
> 
> since your hardirq handler is NULL, you *must* pass IRQF_ONESHOT.

Ok.

> /Could also use devm_request_threaded_irq()

Does not really help much, since the IRQ has to be freed manually anyway
(to ensure it's disabled before usb_remove_phy(); also looks like it's
currently enabled too early...).

> > +	if (ret) {
> > +		dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
> > +			ret);
> > +		goto err_disable_clk;
> > +	}
> > +
> > +	/* Attributes */
> > +	ret = device_create_file(&pdev->dev, &dev_attr_vbus_state);
> > +	ret |= device_create_file(&pdev->dev, &dev_attr_otg_mode);
> 
> heh, Greg wrote a very interesting article recently (look at his blog)
> discussing kernel/userland races wrt creation of sysfs files.

[...]

> what if someone accesses the sysfs file you've already created before
> you call dev_set_drvdata? (not sure  if it's possible).

Yes, that's a bug, will fix.

Thanks for comments,

A.

[PATCH v3 4/4] USB: OMAP1: Tahvo USB transceiver driver

[Felipe Balbi]

Hi,

On Mon, Jul 08, 2013 at 10:44:02PM +0300, Aaro Koskinen wrote:
> > > +static void tahvo_usb_become_host(struct tahvo_usb *tu)
> > > +{
> > > +	struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
> > > +
> > > +	extcon_set_cable_state(&tu->extcon, "USB-HOST", true);
> > > +
> > > +	/* Power up the transceiver in USB host mode */
> > > +	retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
> > > +		   USBR_MASTER_SW2 | USBR_MASTER_SW1);
> > > +	tu->phy.state = OTG_STATE_A_IDLE;
> > > +
> > > +	check_vbus_state(tu);
> > > +}
> > > +
> > > +static void tahvo_usb_stop_host(struct tahvo_usb *tu)
> > > +{
> > > +	tu->phy.state = OTG_STATE_A_IDLE;
> > 
> > shouldn't you undo tahvo_usb_become_host() here ? I mean, set the
> > transceiver to SLAVE ?
> 
> tahvo_usb_become_peripheral() (or power_off) is always called after this
> function. Actually, these stop functions can be eliminated altogether
> as they are only called from a single place...

alright, I guess GCC is already inlining them anyway, your choice.

> > > +static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
> > > +{
> > > +	struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
> > > +
> > > +	dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
> > > +
> > > +	if (otg == NULL)
> > > +		return -ENODEV;
> > > +
> > > +	mutex_lock(&tu->serialize);
> > > +
> > > +	if (host == NULL) {
> > > +		if (tu->tahvo_mode == TAHVO_MODE_HOST)
> > > +			tahvo_usb_power_off(tu);
> > > +		otg->host = NULL;
> > > +		mutex_unlock(&tu->serialize);
> > > +		return 0;
> > > +	}
> > > +
> > > +	if (tu->tahvo_mode == TAHVO_MODE_HOST) {
> > > +		otg->host = NULL;
> > > +		tahvo_usb_become_host(tu);
> > > +	}
> > > +
> > > +	otg->host = host;
> > > +
> > > +	mutex_unlock(&tu->serialize);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int tahvo_usb_set_peripheral(struct usb_otg *otg,
> > > +				    struct usb_gadget *gadget)
> > 
> > I want to get rid of the extra 'gadget' and 'host' parameters on
> > ->set_host() and ->set_peripheral(). Nobody really uses them other than:
> > 
> > my_phy->phy.otg->{gadget,host} = {gadget,host};
> > 
> > For that, I need all other PHYs to stop relying on those parameters and
> > I'll cook patches for that for v3.12 merge window.
> 
> How will the PHY know if there is a host/gadget driver present? I guess
> I will need to wait for those patches...

It won't. We're assuming that if the link asks to become a host, it
should already know that there is a host side available :-)

> > > +static int tahvo_usb_probe(struct platform_device *pdev)
> > > +{
> > > +	struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
> > > +	struct tahvo_usb *tu;
> > > +	int ret;
> > > +
> > > +	tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
> > > +	if (!tu)
> > > +		return -ENOMEM;
> > > +
> > > +	tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
> > > +				   GFP_KERNEL);
> > > +	if (!tu->phy.otg)
> > > +		return -ENOMEM;
> > > +
> > > +	tu->pt_dev = pdev;
> > > +
> > > +	/* Default mode */
> > > +#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
> > > +	tu->tahvo_mode = TAHVO_MODE_HOST;
> > > +#else
> > > +	tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
> > > +#endif
> > 
> > should you call become_host()/become_peripheral() here ?
> 
> Not needed. Once the PHY is registered, the framework will call set_host /
> set_peripheral and the HW gets set to correct state.

ok good, thanks

> > /Could also use devm_request_threaded_irq()
> 
> Does not really help much, since the IRQ has to be freed manually anyway
> (to ensure it's disabled before usb_remove_phy(); also looks like it's
> currently enabled too early...).

you miss a free() in the error path. Switching to
devm_request_threaded_irq() would save you the trouble of having to call
that explicitly.

-- 
balbi
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