usb: phy: add Keystone usb phy driver
authorWingMan Kwok <w-kwok2@ti.com>
Thu, 12 Dec 2013 17:25:30 +0000 (12:25 -0500)
committerFelipe Balbi <balbi@ti.com>
Thu, 12 Dec 2013 19:43:34 +0000 (13:43 -0600)
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>
drivers/usb/phy/Kconfig
drivers/usb/phy/Makefile
drivers/usb/phy/phy-keystone.c [new file with mode: 0644]

index 4f22762f3d6fc1447002d1f21e02342d8296a340..54bebba39e9192b1c48daee2b665ba9e240f95ef 100644 (file)
@@ -48,6 +48,15 @@ config ISP1301_OMAP
          This driver can also be built as a module.  If so, the module
          will be called isp1301_omap.
 
+config KEYSTONE_USB_PHY
+       tristate "Keystone USB PHY Driver"
+       depends on ARCH_KEYSTONE || COMPILE_TEST
+       select NOP_USB_XCEIV
+       help
+         Enable this to support Keystone USB phy. This driver provides
+         interface to interact with USB 2.0 and USB 3.0 PHY that is part
+         of the Keystone SOC.
+
 config MV_U3D_PHY
        bool "Marvell USB 3.0 PHY controller Driver"
        depends on CPU_MMP3
index 9b3be9e0aeb475f5e5c915393161ddd2759638f2..be58adae34960de4508596beb16066ae113348a3 100644 (file)
@@ -32,3 +32,4 @@ obj-$(CONFIG_USB_RCAR_PHY)            += phy-rcar-usb.o
 obj-$(CONFIG_USB_RCAR_GEN2_PHY)                += phy-rcar-gen2-usb.o
 obj-$(CONFIG_USB_ULPI)                 += phy-ulpi.o
 obj-$(CONFIG_USB_ULPI_VIEWPORT)                += phy-ulpi-viewport.o
+obj-$(CONFIG_KEYSTONE_USB_PHY)         += phy-keystone.o
diff --git a/drivers/usb/phy/phy-keystone.c b/drivers/usb/phy/phy-keystone.c
new file mode 100644 (file)
index 0000000..a04fb94
--- /dev/null
@@ -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");