usb: chipidea: Add support for ULPI PHY bus

Some phys for the chipidea controller are controlled via the ULPI
viewport. Add support for the ULPI bus so that these sorts of
phys can be probed and read/written automatically without having
to duplicate the viewport logic in each phy driver.

Acked-by: Peter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>

drivers/usb/chipidea/Kconfig

@@ -38,4 +38,11 @@ config USB_CHIPIDEA_HOST
 	  Say Y here to enable host controller functionality of the
 	  ChipIdea driver.
 
+config USB_CHIPIDEA_ULPI
+	bool "ChipIdea ULPI PHY support"
+	depends on USB_ULPI_BUS=y || USB_ULPI_BUS=USB_CHIPIDEA
+	help
+	  Say Y here if you have a ULPI PHY attached to your ChipIdea
+	  controller.
+
 endif

drivers/usb/chipidea/Makefile

@@ -4,6 +4,7 @@ ci_hdrc-y				:= core.o otg.o debug.o
 ci_hdrc-$(CONFIG_USB_CHIPIDEA_UDC)	+= udc.o
 ci_hdrc-$(CONFIG_USB_CHIPIDEA_HOST)	+= host.o
 ci_hdrc-$(CONFIG_USB_OTG_FSM)		+= otg_fsm.o
+ci_hdrc-$(CONFIG_USB_CHIPIDEA_ULPI)	+= ulpi.o
 
 # Glue/Bridge layers go here
 

drivers/usb/chipidea/ci.h

@@ -18,6 +18,8 @@
 #include <linux/usb.h>
 #include <linux/usb/gadget.h>
 #include <linux/usb/otg-fsm.h>
+#include <linux/usb/otg.h>
+#include <linux/ulpi/interface.h>
 
 /******************************************************************************
  * DEFINE
@@ -52,6 +54,7 @@ enum ci_hw_regs {
 	OP_ENDPTLISTADDR,
 	OP_TTCTRL,
 	OP_BURSTSIZE,
+	OP_ULPI_VIEWPORT,
 	OP_PORTSC,
 	OP_DEVLC,
 	OP_OTGSC,
@@ -187,6 +190,8 @@ struct hw_bank {
  * @test_mode: the selected test mode
  * @platdata: platform specific information supplied by parent device
  * @vbus_active: is VBUS active
+ * @ulpi: pointer to ULPI device, if any
+ * @ulpi_ops: ULPI read/write ops for this device
  * @phy: pointer to PHY, if any
  * @usb_phy: pointer to USB PHY, if any and if using the USB PHY framework
  * @hcd: pointer to usb_hcd for ehci host driver
@@ -236,6 +241,10 @@ struct ci_hdrc {
 
 	struct ci_hdrc_platform_data	*platdata;
 	int				vbus_active;
+#ifdef CONFIG_USB_CHIPIDEA_ULPI
+	struct ulpi			*ulpi;
+	struct ulpi_ops 		ulpi_ops;
+#endif
 	struct phy			*phy;
 	/* old usb_phy interface */
 	struct usb_phy			*usb_phy;
@@ -418,6 +427,16 @@ static inline bool ci_otg_is_fsm_mode(struct ci_hdrc *ci)
 #endif
 }
 
+#if IS_ENABLED(CONFIG_USB_CHIPIDEA_ULPI)
+int ci_ulpi_init(struct ci_hdrc *ci);
+void ci_ulpi_exit(struct ci_hdrc *ci);
+int ci_ulpi_resume(struct ci_hdrc *ci);
+#else
+static inline int ci_ulpi_init(struct ci_hdrc *ci) { return 0; }
+static inline void ci_ulpi_exit(struct ci_hdrc *ci) { }
+static inline int ci_ulpi_resume(struct ci_hdrc *ci) { return 0; }
+#endif
+
 u32 hw_read_intr_enable(struct ci_hdrc *ci);
 
 u32 hw_read_intr_status(struct ci_hdrc *ci);
@@ -428,6 +447,8 @@ int hw_port_test_set(struct ci_hdrc *ci, u8 mode);
 
 u8 hw_port_test_get(struct ci_hdrc *ci);
 
+void hw_phymode_configure(struct ci_hdrc *ci);
+
 void ci_platform_configure(struct ci_hdrc *ci);
 
 int dbg_create_files(struct ci_hdrc *ci);

drivers/usb/chipidea/core.c

@@ -86,6 +86,7 @@ static const u8 ci_regs_nolpm[] = {
 	[OP_ENDPTLISTADDR]	= 0x18U,
 	[OP_TTCTRL]		= 0x1CU,
 	[OP_BURSTSIZE]		= 0x20U,
+	[OP_ULPI_VIEWPORT]	= 0x30U,
 	[OP_PORTSC]		= 0x44U,
 	[OP_DEVLC]		= 0x84U,
 	[OP_OTGSC]		= 0x64U,
@@ -110,6 +111,7 @@ static const u8 ci_regs_lpm[] = {
 	[OP_ENDPTLISTADDR]	= 0x18U,
 	[OP_TTCTRL]		= 0x1CU,
 	[OP_BURSTSIZE]		= 0x20U,
+	[OP_ULPI_VIEWPORT]	= 0x30U,
 	[OP_PORTSC]		= 0x44U,
 	[OP_DEVLC]		= 0x84U,
 	[OP_OTGSC]		= 0xC4U,
@@ -285,7 +287,7 @@ static int hw_device_init(struct ci_hdrc *ci, void __iomem *base)
 	return 0;
 }
 
-static void hw_phymode_configure(struct ci_hdrc *ci)
+void hw_phymode_configure(struct ci_hdrc *ci)
 {
 	u32 portsc, lpm, sts = 0;
 
@@ -879,6 +881,7 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 		CI_HDRC_IMX28_WRITE_FIX);
 	ci->supports_runtime_pm = !!(ci->platdata->flags &
 		CI_HDRC_SUPPORTS_RUNTIME_PM);
+	platform_set_drvdata(pdev, ci);
 
 	ret = hw_device_init(ci, base);
 	if (ret < 0) {
@@ -886,6 +889,10 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
+	ret = ci_ulpi_init(ci);
+	if (ret)
+		return ret;
+
 	if (ci->platdata->phy) {
 		ci->phy = ci->platdata->phy;
 	} else if (ci->platdata->usb_phy) {
@@ -896,11 +903,15 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 
 		/* if both generic PHY and USB PHY layers aren't enabled */
 		if (PTR_ERR(ci->phy) == -ENOSYS &&
-				PTR_ERR(ci->usb_phy) == -ENXIO)
-			return -ENXIO;
+				PTR_ERR(ci->usb_phy) == -ENXIO) {
+			ret = -ENXIO;
+			goto ulpi_exit;
+		}
 
-		if (IS_ERR(ci->phy) && IS_ERR(ci->usb_phy))
-			return -EPROBE_DEFER;
+		if (IS_ERR(ci->phy) && IS_ERR(ci->usb_phy)) {
+			ret = -EPROBE_DEFER;
+			goto ulpi_exit;
+		}
 
 		if (IS_ERR(ci->phy))
 			ci->phy = NULL;
@@ -985,7 +996,6 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 		}
 	}
 
-	platform_set_drvdata(pdev, ci);
 	ret = devm_request_irq(dev, ci->irq, ci_irq, IRQF_SHARED,
 			ci->platdata->name, ci);
 	if (ret)
@@ -1016,6 +1026,8 @@ stop:
 	ci_role_destroy(ci);
 deinit_phy:
 	ci_usb_phy_exit(ci);
+ulpi_exit:
+	ci_ulpi_exit(ci);
 
 	return ret;
 }
@@ -1034,6 +1046,7 @@ static int ci_hdrc_remove(struct platform_device *pdev)
 	ci_role_destroy(ci);
 	ci_hdrc_enter_lpm(ci, true);
 	ci_usb_phy_exit(ci);
+	ci_ulpi_exit(ci);
 
 	return 0;
 }
@@ -1081,6 +1094,7 @@ static void ci_controller_suspend(struct ci_hdrc *ci)
 static int ci_controller_resume(struct device *dev)
 {
 	struct ci_hdrc *ci = dev_get_drvdata(dev);
+	int ret;
 
 	dev_dbg(dev, "at %s\n", __func__);
 
@@ -1090,6 +1104,11 @@ static int ci_controller_resume(struct device *dev)
 	}
 
 	ci_hdrc_enter_lpm(ci, false);
+
+	ret = ci_ulpi_resume(ci);
+	if (ret)
+		return ret;
+
 	if (ci->usb_phy) {
 		usb_phy_set_suspend(ci->usb_phy, 0);
 		usb_phy_set_wakeup(ci->usb_phy, false);

drivers/usb/chipidea/ulpi.c

@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2016 Linaro Ltd.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/device.h>
+#include <linux/usb/chipidea.h>
+#include <linux/ulpi/interface.h>
+
+#include "ci.h"
+
+#define ULPI_WAKEUP		BIT(31)
+#define ULPI_RUN		BIT(30)
+#define ULPI_WRITE		BIT(29)
+#define ULPI_SYNC_STATE		BIT(27)
+#define ULPI_ADDR(n)		((n) << 16)
+#define ULPI_DATA(n)		(n)
+
+static int ci_ulpi_wait(struct ci_hdrc *ci, u32 mask)
+{
+	unsigned long usec = 10000;
+
+	while (usec--) {
+		if (!hw_read(ci, OP_ULPI_VIEWPORT, mask))
+			return 0;
+
+		udelay(1);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static int ci_ulpi_read(struct device *dev, u8 addr)
+{
+	struct ci_hdrc *ci = dev_get_drvdata(dev);
+	int ret;
+
+	hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff, ULPI_WRITE | ULPI_WAKEUP);
+	ret = ci_ulpi_wait(ci, ULPI_WAKEUP);
+	if (ret)
+		return ret;
+
+	hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff, ULPI_RUN | ULPI_ADDR(addr));
+	ret = ci_ulpi_wait(ci, ULPI_RUN);
+	if (ret)
+		return ret;
+
+	return hw_read(ci, OP_ULPI_VIEWPORT, GENMASK(15, 8)) >> 8;
+}
+
+static int ci_ulpi_write(struct device *dev, u8 addr, u8 val)
+{
+	struct ci_hdrc *ci = dev_get_drvdata(dev);
+	int ret;
+
+	hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff, ULPI_WRITE | ULPI_WAKEUP);
+	ret = ci_ulpi_wait(ci, ULPI_WAKEUP);
+	if (ret)
+		return ret;
+
+	hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff,
+		 ULPI_RUN | ULPI_WRITE | ULPI_ADDR(addr) | val);
+	return ci_ulpi_wait(ci, ULPI_RUN);
+}
+
+int ci_ulpi_init(struct ci_hdrc *ci)
+{
+	if (ci->platdata->phy_mode != USBPHY_INTERFACE_MODE_ULPI)
+		return 0;
+
+	/*
+	 * Set PORTSC correctly so we can read/write ULPI registers for
+	 * identification purposes
+	 */
+	hw_phymode_configure(ci);
+
+	ci->ulpi_ops.read = ci_ulpi_read;
+	ci->ulpi_ops.write = ci_ulpi_write;
+	ci->ulpi = ulpi_register_interface(ci->dev, &ci->ulpi_ops);
+	if (IS_ERR(ci->ulpi))
+		dev_err(ci->dev, "failed to register ULPI interface");
+
+	return PTR_ERR_OR_ZERO(ci->ulpi);
+}
+
+void ci_ulpi_exit(struct ci_hdrc *ci)
+{
+	if (ci->ulpi) {
+		ulpi_unregister_interface(ci->ulpi);
+		ci->ulpi = NULL;
+	}
+}
+
+int ci_ulpi_resume(struct ci_hdrc *ci)
+{
+	int cnt = 100000;
+
+	while (cnt-- > 0) {
+		if (hw_read(ci, OP_ULPI_VIEWPORT, ULPI_SYNC_STATE))
+			return 0;
+		udelay(1);
+	}
+
+	return -ETIMEDOUT;
+}