LXR linux/drivers/phy/broadcom/phy-bcm-ns-usb2.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Broadcom Northstar USB 2.0 PHY Driver
   4 *
   5 * Copyright (C) 2016 Rafał Miłecki <zajec5@gmail.com>
   6 */
   7
   8#include <linux/bcma/bcma.h>
   9#include <linux/clk.h>
  10#include <linux/delay.h>
  11#include <linux/err.h>
  12#include <linux/module.h>
  13#include <linux/of_address.h>
  14#include <linux/of_platform.h>
  15#include <linux/phy/phy.h>
  16#include <linux/platform_device.h>
  17#include <linux/slab.h>
  18
  19struct bcm_ns_usb2 {
  20        struct device *dev;
  21        struct clk *ref_clk;
  22        struct phy *phy;
  23        void __iomem *dmu;
  24};
  25
  26static int bcm_ns_usb2_phy_init(struct phy *phy)
  27{
  28        struct bcm_ns_usb2 *usb2 = phy_get_drvdata(phy);
  29        struct device *dev = usb2->dev;
  30        void __iomem *dmu = usb2->dmu;
  31        u32 ref_clk_rate, usb2ctl, usb_pll_ndiv, usb_pll_pdiv;
  32        int err = 0;
  33
  34        err = clk_prepare_enable(usb2->ref_clk);
  35        if (err < 0) {
  36                dev_err(dev, "Failed to prepare ref clock: %d\n", err);
  37                goto err_out;
  38        }
  39
  40        ref_clk_rate = clk_get_rate(usb2->ref_clk);
  41        if (!ref_clk_rate) {
  42                dev_err(dev, "Failed to get ref clock rate\n");
  43                err = -EINVAL;
  44                goto err_clk_off;
  45        }
  46
  47        usb2ctl = readl(dmu + BCMA_DMU_CRU_USB2_CONTROL);
  48
  49        if (usb2ctl & BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK) {
  50                usb_pll_pdiv = usb2ctl;
  51                usb_pll_pdiv &= BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK;
  52                usb_pll_pdiv >>= BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_SHIFT;
  53        } else {
  54                usb_pll_pdiv = 1 << 3;
  55        }
  56
  57        /* Calculate ndiv based on a solid 1920 MHz that is for USB2 PHY */
  58        usb_pll_ndiv = (1920000000 * usb_pll_pdiv) / ref_clk_rate;
  59
  60        /* Unlock DMU PLL settings with some magic value */
  61        writel(0x0000ea68, dmu + BCMA_DMU_CRU_CLKSET_KEY);
  62
  63        /* Write USB 2.0 PLL control setting */
  64        usb2ctl &= ~BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_MASK;
  65        usb2ctl |= usb_pll_ndiv << BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_SHIFT;
  66        writel(usb2ctl, dmu + BCMA_DMU_CRU_USB2_CONTROL);
  67
  68        /* Lock DMU PLL settings */
  69        writel(0x00000000, dmu + BCMA_DMU_CRU_CLKSET_KEY);
  70
  71err_clk_off:
  72        clk_disable_unprepare(usb2->ref_clk);
  73err_out:
  74        return err;
  75}
  76
  77static const struct phy_ops ops = {
  78        .init           = bcm_ns_usb2_phy_init,
  79        .owner          = THIS_MODULE,
  80};
  81
  82static int bcm_ns_usb2_probe(struct platform_device *pdev)
  83{
  84        struct device *dev = &pdev->dev;
  85        struct bcm_ns_usb2 *usb2;
  86        struct phy_provider *phy_provider;
  87
  88        usb2 = devm_kzalloc(&pdev->dev, sizeof(*usb2), GFP_KERNEL);
  89        if (!usb2)
  90                return -ENOMEM;
  91        usb2->dev = dev;
  92
  93        usb2->dmu = devm_platform_ioremap_resource_byname(pdev, "dmu");
  94        if (IS_ERR(usb2->dmu)) {
  95                dev_err(dev, "Failed to map DMU regs\n");
  96                return PTR_ERR(usb2->dmu);
  97        }
  98
  99        usb2->ref_clk = devm_clk_get(dev, "phy-ref-clk");
 100        if (IS_ERR(usb2->ref_clk)) {
 101                dev_err(dev, "Clock not defined\n");
 102                return PTR_ERR(usb2->ref_clk);
 103        }
 104
 105        usb2->phy = devm_phy_create(dev, NULL, &ops);
 106        if (IS_ERR(usb2->phy))
 107                return PTR_ERR(usb2->phy);
 108
 109        phy_set_drvdata(usb2->phy, usb2);
 110        platform_set_drvdata(pdev, usb2);
 111
 112        phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 113        return PTR_ERR_OR_ZERO(phy_provider);
 114}
 115
 116static const struct of_device_id bcm_ns_usb2_id_table[] = {
 117        { .compatible = "brcm,ns-usb2-phy", },
 118        {},
 119};
 120MODULE_DEVICE_TABLE(of, bcm_ns_usb2_id_table);
 121
 122static struct platform_driver bcm_ns_usb2_driver = {
 123        .probe          = bcm_ns_usb2_probe,
 124        .driver = {
 125                .name = "bcm_ns_usb2",
 126                .of_match_table = bcm_ns_usb2_id_table,
 127        },
 128};
 129module_platform_driver(bcm_ns_usb2_driver);
 130
 131MODULE_LICENSE("GPL v2");
 132