Re: [RFC PATCH 07/11] mfd: omap: control: usb-phy: introduce the ctrl-module usb driver

Created a new platform driver for the platform device created by the
control module mfd core, wrt usb. This driver has API's to power on/off
the phy and the API's to write to musb mailbox.

(p.s. the mailbox for musb in omap4 is present in system control
module)

[kishon@ti.com: wrote the original API's related to USB functions]
Signed-off-by: Kishon Vijay Abraham I <redacted>
Signed-off-by: Eduardo Valentin <redacted>
---
 drivers/usb/otg/Kconfig           |   13 ++++
 drivers/usb/otg/Makefile          |    1 +
 drivers/usb/otg/omap4-usb-phy.c   |  130 +++++++++++++++++++++++++++++++++++++
 include/linux/usb/omap4_usb_phy.h |   53 +++++++++++++++
 4 files changed, 197 insertions(+), 0 deletions(-)
 create mode 100644 drivers/usb/otg/omap4-usb-phy.c
 create mode 100644 include/linux/usb/omap4_usb_phy.h

diff --git a/drivers/usb/otg/Kconfig b/drivers/usb/otg/Kconfig
index 5c87db0..e2840f1 100644
--- a/drivers/usb/otg/Kconfig
+++ b/drivers/usb/otg/Kconfig

@@ -78,6 +78,19 @@ config TWL6030_USB

         are hooked to this driver through platform_data structure.
         The definition of internal PHY APIs are in the mach-omap2 layer.

+config OMAP4_USB_PHY
+       tristate "Texas Instruments OMAP4+ USB pin control driver"
+       depends on MFD_OMAP_CONTROL
+       help
+         If you say yes here you get support for the Texas Instruments
+         OMAP4+ USB pin control driver. The register set is part of system
+         control module.
+
+         USB phy in OMAP configures control module register for powering on
+         the phy, configuring VBUSVALID, AVALID, IDDIG and SESSEND. For
+         performing the above mentioned configuration, API's are added in
+         by this children of the control module driver.
+
 config NOP_USB_XCEIV
       tristate "NOP USB Transceiver Driver"
       select USB_OTG_UTILS

diff --git a/drivers/usb/otg/Makefile b/drivers/usb/otg/Makefile
index 41aa509..60c8c83 100644
--- a/drivers/usb/otg/Makefile
+++ b/drivers/usb/otg/Makefile

@@ -13,6 +13,7 @@ obj-$(CONFIG_USB_GPIO_VBUS)   += gpio_vbus.o

 obj-$(CONFIG_ISP1301_OMAP)     += isp1301_omap.o
 obj-$(CONFIG_TWL4030_USB)      += twl4030-usb.o
 obj-$(CONFIG_TWL6030_USB)      += twl6030-usb.o
+obj-$(CONFIG_OMAP4_USB_PHY)    += omap4-usb-phy.o
 obj-$(CONFIG_NOP_USB_XCEIV)    += nop-usb-xceiv.o
 obj-$(CONFIG_USB_ULPI)         += ulpi.o
 obj-$(CONFIG_USB_ULPI_VIEWPORT)        += ulpi_viewport.o

diff --git a/drivers/usb/otg/omap4-usb-phy.c b/drivers/usb/otg/omap4-usb-phy.c
new file mode 100644
index 0000000..a29ea45
--- /dev/null
+++ b/drivers/usb/otg/omap4-usb-phy.c

@@ -0,0 +1,130 @@
+/*
+ * OMAP4 system control module driver, USB control children
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * Contact:
+ *    Kishon Vijay Abraham I <kishon@ti.com>
+ *    Eduardo Valentin <eduardo.valentin@ti.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 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/omap_control.h>
+#include <linux/usb/omap4_usb_phy.h>
+
+/**
+ * omap4_usb_phy_power - power on/off the phy using control module reg
+ * @dev: struct device *
+ * @on: 0 or 1, based on powering on or off the PHY

+ *
+ * omap_usb2 can call this API to power on or off the PHY.
+ */
+int omap4_usb_phy_power(struct device *dev, int on)
+{
+       u32 val;
+       int ret;
+
+       if (on) {
+               ret = omap_control_readl(dev, CONTROL_DEV_CONF, &val);
+               if (!ret && (val & PHY_PD)) {
+                       ret = omap_control_writel(dev, ~PHY_PD,
+                                                 CONTROL_DEV_CONF);
+                       /* XXX: add proper documentation for this delay */
+                       mdelay(200);