Re: [PATCH v1 01/11] drivers: usb: otg: add a new driver for omapusb2 phy

From: Rajendra Nayak
Date: Tue Jul 10 2012 - 01:47:17 EST


diff --git a/Documentation/devicetree/bindings/usb/omap-usb.txt b/Documentation/devicetree/bindings/usb/omap-usb.txt
new file mode 100644
index 0000000..80a28c9
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/omap-usb.txt
@@ -0,0 +1,16 @@
+OMAP USB PHY
+
+OMAP USB2 PHY
+
+Required properties:
+ - compatible: Should be "ti,omap-usb2"
+ - reg : Address and length of the register set for the device. Also
+add the address of control module dev conf register until a driver for
+control module is added
+
+This is usually a subnode of ocp2scp to which it is connected.
+
+usb2phy@0x4a0ad080 {
+ compatible = "ti,omap-usb2";
+ reg =<0x4a0ad080 0x58>;

Don;t you need a 'ti,hwmods' entry for this one?

--- /dev/null
+++ b/drivers/usb/otg/omap-usb2.c
@@ -0,0 +1,273 @@
+/*
+ * omap-usb2.c - USB PHY, talking to musb controller in OMAP.
+ *
+ * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com

Copyright (C) 2012? Same for the couple of headers below.

+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Author: Kishon Vijay Abraham I<kishon@xxxxxx>
+ *
+ * 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.
+ *
+ */
+

+
+static int __devinit omap_usb2_probe(struct platform_device *pdev)
+{
+ struct omap_usb *phy;
+ struct usb_otg *otg;
+ struct resource *res;
+
+ phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
+ if (!phy) {
+ dev_err(&pdev->dev, "unable to allocate memory for USB2 PHY\n");
+ return -ENOMEM;
+ }
+
+ otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
+ if (!otg) {
+ dev_err(&pdev->dev, "unable to allocate memory for USB OTG\n");
+ return -ENOMEM;
+ }
+
+ phy->dev =&pdev->dev;
+
+ phy->phy.dev = phy->dev;
+ phy->phy.label = "omap-usb2";
+ phy->phy.set_suspend = omap_usb2_suspend;
+ phy->phy.otg = otg;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+
+ phy->control_dev_conf = devm_request_and_ioremap(&pdev->dev, res);
+ if (phy->control_dev_conf == NULL) {
+ dev_err(&pdev->dev, "Failed to obtain io memory\n");
+ return -ENXIO;
+ }
+
+ phy->is_suspended = 1;
+ omap_usb_phy_power(phy, 0);
+
+ otg->set_host = omap_usb_set_host;
+ otg->set_peripheral = omap_usb_set_peripheral;
+ otg->set_vbus = omap_usb_set_vbus;
+ otg->start_srp = omap_usb_start_srp;
+ otg->phy =&phy->phy;
+
+ phy->wkupclk = devm_clk_get(phy->dev, "usb_phy_cm_clk32k");

Why not just use clk_get()? What does devm_clk_get() do?

+ if (IS_ERR(phy->wkupclk)) {
+ dev_err(&pdev->dev, "unable to get usb_phy_cm_clk32k\n");
+ return PTR_ERR(phy->wkupclk);
+ }
+ clk_prepare(phy->wkupclk);

Ideally clk_prepare() is an extension of clk_enable() and is expected
to be used that way. Not to be clubbed with clk_get(). Same with
clk_unprepare(). Do you do a clk_enable()/_disable() in interrupt/
atomic context?

+
+ usb_add_phy(&phy->phy, USB_PHY_TYPE_USB2);
+
+ platform_set_drvdata(pdev, phy);
+
+ pm_runtime_enable(phy->dev);
+
+ return 0;
+}
+
+static int __devexit omap_usb2_remove(struct platform_device *pdev)
+{
+ struct omap_usb *phy = platform_get_drvdata(pdev);
+
+ clk_unprepare(phy->wkupclk);
+ usb_remove_phy(&phy->phy);
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int omap_usb2_runtime_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct omap_usb *phy = platform_get_drvdata(pdev);
+
+ clk_disable(phy->wkupclk);
+
+ return 0;
+}
+
+static int omap_usb2_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct omap_usb *phy = platform_get_drvdata(pdev);
+
+ clk_enable(phy->wkupclk);
+
+ return 0;
+}
+
+static const struct dev_pm_ops omap_usb2_pm_ops = {
+ SET_RUNTIME_PM_OPS(omap_usb2_runtime_suspend, omap_usb2_runtime_resume,
+ NULL)
+};
+
+#define DEV_PM_OPS (&omap_usb2_pm_ops)
+#else
+#define DEV_PM_OPS NULL
+#endif
+
+#ifdef CONFIG_OF
+static const struct of_device_id omap_usb2_id_table[] = {
+ { .compatible = "ti,omap-usb2" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, omap_usb2_id_table);
+#else
+#define omap_usb2_id_table NULL;
+#endif
+
+static struct platform_driver omap_usb2_driver = {
+ .probe = omap_usb2_probe,
+ .remove = __devexit_p(omap_usb2_remove),
+ .driver = {
+ .name = "omap-usb2",
+ .owner = THIS_MODULE,
+ .pm = DEV_PM_OPS,
+ .of_match_table = omap_usb2_id_table,

Use of_match_ptr() instead.

regards,
Rajendra

+ },
+};
+
+static int __init usb2_omap_init(void)
+{
+ return platform_driver_register(&omap_usb2_driver);
+}
+arch_initcall(usb2_omap_init);
+
+static void __exit usb2_omap_exit(void)
+{
+ platform_driver_unregister(&omap_usb2_driver);
+}
+module_exit(usb2_omap_exit);
+
+MODULE_ALIAS("platform: omap_usb2");
+MODULE_AUTHOR("Texas Instruments Inc.");
+MODULE_DESCRIPTION("OMAP USB2 PHY DRIVER");
+MODULE_LICENSE("GPLv2");
diff --git a/include/linux/usb/omap_usb.h b/include/linux/usb/omap_usb.h
new file mode 100644
index 0000000..ebcbca6
--- /dev/null
+++ b/include/linux/usb/omap_usb.h
@@ -0,0 +1,45 @@
+/*
+ * omap_usb.h -- omap usb2 phy header file
+ *
+ * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Author: Kishon Vijay Abraham I<kishon@xxxxxx>
+ *
+ * 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 __DRIVERS_OMAP_USB2_H
+#define __DRIVERS_OMAP_USB2_H
+
+#include<linux/usb/otg.h>
+
+struct omap_usb {
+ struct usb_phy phy;
+ struct phy_companion *comparator;
+ struct device *dev;
+ u32 __iomem *control_dev_conf;
+ struct clk *wkupclk;
+ u8 is_suspended:1;
+};
+
+#define PHY_PD 0x1
+
+#define phy_to_omapusb(x) container_of((x), struct omap_usb, phy)
+
+#if defined(CONFIG_OMAP_USB2) || defined(CONFIG_OMAP_USB2_MODULE)
+void omap_usb2_set_comparator(struct phy_companion *comparator);
+#else
+static inline void omap_usb2_set_comparator(struct phy_companion *comparator)
+{
+}
+#endif
+
+#endif /* __DRIVERS_OMAP_USB_H */
diff --git a/include/linux/usb/phy_companion.h b/include/linux/usb/phy_companion.h
new file mode 100644
index 0000000..321290f
--- /dev/null
+++ b/include/linux/usb/phy_companion.h
@@ -0,0 +1,34 @@
+/*
+ * phy-companion.h -- phy companion to indicate the comparator part of PHY
+ *
+ * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Author: Kishon Vijay Abraham I<kishon@xxxxxx>
+ *
+ * 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 __DRIVERS_PHY_COMPANION_H
+#define __DRIVERS_PHY_COMPANION_H
+
+#include<linux/usb/otg.h>
+
+/* phy_companion to take care of VBUS, ID and srp capabilities */
+struct phy_companion {
+
+ /* effective for A-peripheral, ignored for B devices */
+ int (*set_vbus)(struct phy_companion *x, bool enabled);
+
+ /* for B devices only: start session with A-Host */
+ int (*start_srp)(struct phy_companion *x);
+};
+
+#endif /* __DRIVERS_PHY_COMPANION_H */

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