phy/broadcom/phy-bcm-kona-usb2.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * phy-bcm-kona-usb2.c - Broadcom Kona USB2 Phy Driver
0004  *
0005  * Copyright (C) 2013 Linaro Limited
0006  * Matt Porter <mporter@linaro.org>
0007  */
0008
0009 #include <linux/clk.h>
0010 #include <linux/delay.h>
0011 #include <linux/err.h>
0012 #include <linux/io.h>
0013 #include <linux/module.h>
0014 #include <linux/of.h>
0015 #include <linux/phy/phy.h>
0016 #include <linux/platform_device.h>
0017
0018 #define OTGCTL          (0)
0019 #define OTGCTL_OTGSTAT2     BIT(31)
0020 #define OTGCTL_OTGSTAT1     BIT(30)
0021 #define OTGCTL_PRST_N_SW    BIT(11)
0022 #define OTGCTL_HRESET_N     BIT(10)
0023 #define OTGCTL_UTMI_LINE_STATE1 BIT(9)
0024 #define OTGCTL_UTMI_LINE_STATE0 BIT(8)
0025
0026 #define P1CTL           (8)
0027 #define P1CTL_SOFT_RESET    BIT(1)
0028 #define P1CTL_NON_DRIVING   BIT(0)
0029
0030 struct bcm_kona_usb {
0031     void __iomem *regs;
0032 };
0033
0034 static void bcm_kona_usb_phy_power(struct bcm_kona_usb *phy, int on)
0035 {
0036     u32 val;
0037
0038     val = readl(phy->regs + OTGCTL);
0039     if (on) {
0040         /* Configure and power PHY */
0041         val &= ~(OTGCTL_OTGSTAT2 | OTGCTL_OTGSTAT1 |
0042              OTGCTL_UTMI_LINE_STATE1 | OTGCTL_UTMI_LINE_STATE0);
0043         val |= OTGCTL_PRST_N_SW | OTGCTL_HRESET_N;
0044     } else {
0045         val &= ~(OTGCTL_PRST_N_SW | OTGCTL_HRESET_N);
0046     }
0047     writel(val, phy->regs + OTGCTL);
0048 }
0049
0050 static int bcm_kona_usb_phy_init(struct phy *gphy)
0051 {
0052     struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
0053     u32 val;
0054
0055     /* Soft reset PHY */
0056     val = readl(phy->regs + P1CTL);
0057     val &= ~P1CTL_NON_DRIVING;
0058     val |= P1CTL_SOFT_RESET;
0059     writel(val, phy->regs + P1CTL);
0060     writel(val & ~P1CTL_SOFT_RESET, phy->regs + P1CTL);
0061     /* Reset needs to be asserted for 2ms */
0062     mdelay(2);
0063     writel(val | P1CTL_SOFT_RESET, phy->regs + P1CTL);
0064
0065     return 0;
0066 }
0067
0068 static int bcm_kona_usb_phy_power_on(struct phy *gphy)
0069 {
0070     struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
0071
0072     bcm_kona_usb_phy_power(phy, 1);
0073
0074     return 0;
0075 }
0076
0077 static int bcm_kona_usb_phy_power_off(struct phy *gphy)
0078 {
0079     struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
0080
0081     bcm_kona_usb_phy_power(phy, 0);
0082
0083     return 0;
0084 }
0085
0086 static const struct phy_ops ops = {
0087     .init       = bcm_kona_usb_phy_init,
0088     .power_on   = bcm_kona_usb_phy_power_on,
0089     .power_off  = bcm_kona_usb_phy_power_off,
0090     .owner      = THIS_MODULE,
0091 };
0092
0093 static int bcm_kona_usb2_probe(struct platform_device *pdev)
0094 {
0095     struct device *dev = &pdev->dev;
0096     struct bcm_kona_usb *phy;
0097     struct phy *gphy;
0098     struct phy_provider *phy_provider;
0099
0100     phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
0101     if (!phy)
0102         return -ENOMEM;
0103
0104     phy->regs = devm_platform_ioremap_resource(pdev, 0);
0105     if (IS_ERR(phy->regs))
0106         return PTR_ERR(phy->regs);
0107
0108     platform_set_drvdata(pdev, phy);
0109
0110     gphy = devm_phy_create(dev, NULL, &ops);
0111     if (IS_ERR(gphy))
0112         return PTR_ERR(gphy);
0113
0114     /* The Kona PHY supports an 8-bit wide UTMI interface */
0115     phy_set_bus_width(gphy, 8);
0116
0117     phy_set_drvdata(gphy, phy);
0118
0119     phy_provider = devm_of_phy_provider_register(dev,
0120             of_phy_simple_xlate);
0121
0122     return PTR_ERR_OR_ZERO(phy_provider);
0123 }
0124
0125 static const struct of_device_id bcm_kona_usb2_dt_ids[] = {
0126     { .compatible = "brcm,kona-usb2-phy" },
0127     { /* sentinel */ }
0128 };
0129
0130 MODULE_DEVICE_TABLE(of, bcm_kona_usb2_dt_ids);
0131
0132 static struct platform_driver bcm_kona_usb2_driver = {
0133     .probe      = bcm_kona_usb2_probe,
0134     .driver     = {
0135         .name   = "bcm-kona-usb2",
0136         .of_match_table = bcm_kona_usb2_dt_ids,
0137     },
0138 };
0139
0140 module_platform_driver(bcm_kona_usb2_driver);
0141
0142 MODULE_ALIAS("platform:bcm-kona-usb2");
0143 MODULE_AUTHOR("Matt Porter <mporter@linaro.org>");
0144 MODULE_DESCRIPTION("BCM Kona USB 2.0 PHY driver");
0145 MODULE_LICENSE("GPL v2");