usb/phy/phy-keystone.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * phy-keystone - USB PHY, talking to dwc3 controller in Keystone.
0004  *
0005  * Copyright (C) 2013 Texas Instruments Incorporated - https://www.ti.com
0006  *
0007  * Author: WingMan Kwok <w-kwok2@ti.com>
0008  */
0009
0010 #include <linux/module.h>
0011 #include <linux/platform_device.h>
0012 #include <linux/usb/usb_phy_generic.h>
0013 #include <linux/io.h>
0014 #include <linux/of.h>
0015
0016 #include "phy-generic.h"
0017
0018 /* USB PHY control register offsets */
0019 #define USB_PHY_CTL_UTMI        0x0000
0020 #define USB_PHY_CTL_PIPE        0x0004
0021 #define USB_PHY_CTL_PARAM_1     0x0008
0022 #define USB_PHY_CTL_PARAM_2     0x000c
0023 #define USB_PHY_CTL_CLOCK       0x0010
0024 #define USB_PHY_CTL_PLL         0x0014
0025
0026 #define PHY_REF_SSP_EN          BIT(29)
0027
0028 struct keystone_usbphy {
0029     struct usb_phy_generic  usb_phy_gen;
0030     void __iomem            *phy_ctrl;
0031 };
0032
0033 static inline u32 keystone_usbphy_readl(void __iomem *base, u32 offset)
0034 {
0035     return readl(base + offset);
0036 }
0037
0038 static inline void keystone_usbphy_writel(void __iomem *base,
0039                       u32 offset, u32 value)
0040 {
0041     writel(value, base + offset);
0042 }
0043
0044 static int keystone_usbphy_init(struct usb_phy *phy)
0045 {
0046     struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
0047     u32 val;
0048
0049     val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
0050     keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
0051                 val | PHY_REF_SSP_EN);
0052     return 0;
0053 }
0054
0055 static void keystone_usbphy_shutdown(struct usb_phy *phy)
0056 {
0057     struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
0058     u32 val;
0059
0060     val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
0061     keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
0062                 val & ~PHY_REF_SSP_EN);
0063 }
0064
0065 static int keystone_usbphy_probe(struct platform_device *pdev)
0066 {
0067     struct device       *dev = &pdev->dev;
0068     struct keystone_usbphy  *k_phy;
0069     int ret;
0070
0071     k_phy = devm_kzalloc(dev, sizeof(*k_phy), GFP_KERNEL);
0072     if (!k_phy)
0073         return -ENOMEM;
0074
0075     k_phy->phy_ctrl = devm_platform_ioremap_resource(pdev, 0);
0076     if (IS_ERR(k_phy->phy_ctrl))
0077         return PTR_ERR(k_phy->phy_ctrl);
0078
0079     ret = usb_phy_gen_create_phy(dev, &k_phy->usb_phy_gen);
0080     if (ret)
0081         return ret;
0082
0083     k_phy->usb_phy_gen.phy.init = keystone_usbphy_init;
0084     k_phy->usb_phy_gen.phy.shutdown = keystone_usbphy_shutdown;
0085
0086     platform_set_drvdata(pdev, k_phy);
0087
0088     return usb_add_phy_dev(&k_phy->usb_phy_gen.phy);
0089 }
0090
0091 static int keystone_usbphy_remove(struct platform_device *pdev)
0092 {
0093     struct keystone_usbphy *k_phy = platform_get_drvdata(pdev);
0094
0095     usb_remove_phy(&k_phy->usb_phy_gen.phy);
0096
0097     return 0;
0098 }
0099
0100 static const struct of_device_id keystone_usbphy_ids[] = {
0101     { .compatible = "ti,keystone-usbphy" },
0102     { }
0103 };
0104 MODULE_DEVICE_TABLE(of, keystone_usbphy_ids);
0105
0106 static struct platform_driver keystone_usbphy_driver = {
0107     .probe          = keystone_usbphy_probe,
0108     .remove         = keystone_usbphy_remove,
0109     .driver         = {
0110         .name   = "keystone-usbphy",
0111         .of_match_table = keystone_usbphy_ids,
0112     },
0113 };
0114
0115 module_platform_driver(keystone_usbphy_driver);
0116
0117 MODULE_ALIAS("platform:keystone-usbphy");
0118 MODULE_AUTHOR("Texas Instruments Inc.");
0119 MODULE_DESCRIPTION("Keystone USB phy driver");
0120 MODULE_LICENSE("GPL v2");