usb: phy: add Keystone usb phy driver
Add Keystone platform USB PHY driver support. Current main purpose
of this driver is to enable the PHY reference clock gate on the
Keystone SoC. Otherwise it is a nop PHY.
[ balbi@ti.com : add COMPILE_TEST as a possible dependency
make sure drvdata is initialized before adding PHY ]
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: WingMan Kwok <w-kwok2@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/phy/phy-keystone.c b/drivers/usb/phy/phy-keystone.c
new file mode 100644
index 0000000..a04fb94
--- /dev/null
+++ b/drivers/usb/phy/phy-keystone.c
@@ -0,0 +1,142 @@
+/*
+ * phy-keystone - USB PHY, talking to dwc3 controller in Keystone.
+ *
+ * Copyright (C) 2013 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: WingMan Kwok <w-kwok2@ti.com>
+ *
+ * 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/module.h>
+#include <linux/platform_device.h>
+#include <linux/usb/usb_phy_gen_xceiv.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#include "phy-generic.h"
+
+/* USB PHY control register offsets */
+#define USB_PHY_CTL_UTMI 0x0000
+#define USB_PHY_CTL_PIPE 0x0004
+#define USB_PHY_CTL_PARAM_1 0x0008
+#define USB_PHY_CTL_PARAM_2 0x000c
+#define USB_PHY_CTL_CLOCK 0x0010
+#define USB_PHY_CTL_PLL 0x0014
+
+#define PHY_REF_SSP_EN BIT(29)
+
+struct keystone_usbphy {
+ struct usb_phy_gen_xceiv usb_phy_gen;
+ void __iomem *phy_ctrl;
+};
+
+static inline u32 keystone_usbphy_readl(void __iomem *base, u32 offset)
+{
+ return readl(base + offset);
+}
+
+static inline void keystone_usbphy_writel(void __iomem *base,
+ u32 offset, u32 value)
+{
+ writel(value, base + offset);
+}
+
+static int keystone_usbphy_init(struct usb_phy *phy)
+{
+ struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
+ u32 val;
+
+ val = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
+ keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
+ val | PHY_REF_SSP_EN);
+ return 0;
+}
+
+static void keystone_usbphy_shutdown(struct usb_phy *phy)
+{
+ struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
+ u32 val;
+
+ val = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
+ keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
+ val &= ~PHY_REF_SSP_EN);
+}
+
+static int keystone_usbphy_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct keystone_usbphy *k_phy;
+ struct resource *res;
+ int ret;
+
+ k_phy = devm_kzalloc(dev, sizeof(*k_phy), GFP_KERNEL);
+ if (!k_phy)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "missing usb phy resource\n");
+ return -EINVAL;
+ }
+
+ k_phy->phy_ctrl = devm_ioremap_resource(dev, res);
+ if (IS_ERR(k_phy->phy_ctrl))
+ return PTR_ERR(k_phy->phy_ctrl);
+
+ ret = usb_phy_gen_create_phy(dev, &k_phy->usb_phy_gen,
+ USB_PHY_TYPE_USB2, 0, false);
+ if (ret)
+ return ret;
+
+ k_phy->usb_phy_gen.phy.init = keystone_usbphy_init;
+ k_phy->usb_phy_gen.phy.shutdown = keystone_usbphy_shutdown;
+
+ platform_set_drvdata(pdev, k_phy);
+
+ ret = usb_add_phy_dev(&k_phy->usb_phy_gen.phy);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int keystone_usbphy_remove(struct platform_device *pdev)
+{
+ struct keystone_usbphy *k_phy = platform_get_drvdata(pdev);
+
+ usb_remove_phy(&k_phy->usb_phy_gen.phy);
+
+ return 0;
+}
+
+static const struct of_device_id keystone_usbphy_ids[] = {
+ { .compatible = "ti,keystone-usbphy" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, keystone_usbphy_ids);
+
+static struct platform_driver keystone_usbphy_driver = {
+ .probe = keystone_usbphy_probe,
+ .remove = keystone_usbphy_remove,
+ .driver = {
+ .name = "keystone-usbphy",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(keystone_usbphy_ids),
+ },
+};
+
+module_platform_driver(keystone_usbphy_driver);
+
+MODULE_ALIAS("platform:keystone-usbphy");
+MODULE_AUTHOR("Texas Instruments Inc.");
+MODULE_DESCRIPTION("Keystone USB phy driver");
+MODULE_LICENSE("GPL v2");