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/mfd/syscon.h>
  13 #include <linux/module.h>
  14 #include <linux/of_address.h>
  15 #include <linux/of_platform.h>
  16 #include <linux/phy/phy.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/regmap.h>
  19 #include <linux/slab.h>
  20
  21 struct bcm_ns_usb2 {
  22         struct device *dev;
  23         struct clk *ref_clk;
  24         struct phy *phy;
  25         struct regmap *clkset;
  26         void __iomem *base;
  27
  28         /* Deprecated binding */
  29         void __iomem *dmu;
  30 };
  31
  32 static int bcm_ns_usb2_phy_init(struct phy *phy)
  33 {
  34         struct bcm_ns_usb2 *usb2 = phy_get_drvdata(phy);
  35         struct device *dev = usb2->dev;
  36         u32 ref_clk_rate, usb2ctl, usb_pll_ndiv, usb_pll_pdiv;
  37         int err = 0;
  38
  39         err = clk_prepare_enable(usb2->ref_clk);
  40         if (err < 0) {
  41                 dev_err(dev, "Failed to prepare ref clock: %d\n", err);
  42                 goto err_out;
  43         }
  44
  45         ref_clk_rate = clk_get_rate(usb2->ref_clk);
  46         if (!ref_clk_rate) {
  47                 dev_err(dev, "Failed to get ref clock rate\n");
  48                 err = -EINVAL;
  49                 goto err_clk_off;
  50         }
  51
  52         if (usb2->base)
  53                 usb2ctl = readl(usb2->base);
  54         else
  55                 usb2ctl = readl(usb2->dmu + BCMA_DMU_CRU_USB2_CONTROL);
  56
  57         if (usb2ctl & BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK) {
  58                 usb_pll_pdiv = usb2ctl;
  59                 usb_pll_pdiv &= BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK;
  60                 usb_pll_pdiv >>= BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_SHIFT;
  61         } else {
  62                 usb_pll_pdiv = 1 << 3;
  63         }
  64
  65         /* Calculate ndiv based on a solid 1920 MHz that is for USB2 PHY */
  66         usb_pll_ndiv = (1920000000 * usb_pll_pdiv) / ref_clk_rate;
  67
  68         /* Unlock DMU PLL settings with some magic value */
  69         if (usb2->clkset)
  70                 regmap_write(usb2->clkset, 0, 0x0000ea68);
  71         else
  72                 writel(0x0000ea68, usb2->dmu + BCMA_DMU_CRU_CLKSET_KEY);
  73
  74         /* Write USB 2.0 PLL control setting */
  75         usb2ctl &= ~BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_MASK;
  76         usb2ctl |= usb_pll_ndiv << BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_SHIFT;
  77         if (usb2->base)
  78                 writel(usb2ctl, usb2->base);
  79         else
  80                 writel(usb2ctl, usb2->dmu + BCMA_DMU_CRU_USB2_CONTROL);
  81
  82         /* Lock DMU PLL settings */
  83         if (usb2->clkset)
  84                 regmap_write(usb2->clkset, 0, 0x00000000);
  85         else
  86                 writel(0x00000000, usb2->dmu + BCMA_DMU_CRU_CLKSET_KEY);
  87
  88 err_clk_off:
  89         clk_disable_unprepare(usb2->ref_clk);
  90 err_out:
  91         return err;
  92 }
  93
  94 static const struct phy_ops ops = {
  95         .init           = bcm_ns_usb2_phy_init,
  96         .owner          = THIS_MODULE,
  97 };
  98
  99 static int bcm_ns_usb2_probe(struct platform_device *pdev)
 100 {
 101         struct device *dev = &pdev->dev;
 102         struct bcm_ns_usb2 *usb2;
 103         struct phy_provider *phy_provider;
 104
 105         usb2 = devm_kzalloc(&pdev->dev, sizeof(*usb2), GFP_KERNEL);
 106         if (!usb2)
 107                 return -ENOMEM;
 108         usb2->dev = dev;
 109
 110         if (of_property_present(dev->of_node, "brcm,syscon-clkset")) {
 111                 usb2->base = devm_platform_ioremap_resource(pdev, 0);
 112                 if (IS_ERR(usb2->base)) {
 113                         dev_err(dev, "Failed to map control reg\n");
 114                         return PTR_ERR(usb2->base);
 115                 }
 116
 117                 usb2->clkset = syscon_regmap_lookup_by_phandle(dev->of_node,
 118                                                                "brcm,syscon-clkset");
 119                 if (IS_ERR(usb2->clkset)) {
 120                         dev_err(dev, "Failed to lookup clkset regmap\n");
 121                         return PTR_ERR(usb2->clkset);
 122                 }
 123         } else {
 124                 usb2->dmu = devm_platform_ioremap_resource_byname(pdev, "dmu");
 125                 if (IS_ERR(usb2->dmu)) {
 126                         dev_err(dev, "Failed to map DMU regs\n");
 127                         return PTR_ERR(usb2->dmu);
 128                 }
 129
 130                 dev_warn(dev, "using deprecated DT binding\n");
 131         }
 132
 133         usb2->ref_clk = devm_clk_get(dev, "phy-ref-clk");
 134         if (IS_ERR(usb2->ref_clk)) {
 135                 dev_err_probe(dev, PTR_ERR(usb2->ref_clk), "failed to get ref clk\n");
 136                 return PTR_ERR(usb2->ref_clk);
 137         }
 138
 139         usb2->phy = devm_phy_create(dev, NULL, &ops);
 140         if (IS_ERR(usb2->phy))
 141                 return PTR_ERR(usb2->phy);
 142
 143         phy_set_drvdata(usb2->phy, usb2);
 144         platform_set_drvdata(pdev, usb2);
 145
 146         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 147         return PTR_ERR_OR_ZERO(phy_provider);
 148 }
 149
 150 static const struct of_device_id bcm_ns_usb2_id_table[] = {
 151         { .compatible = "brcm,ns-usb2-phy", },
 152         {},
 153 };
 154 MODULE_DEVICE_TABLE(of, bcm_ns_usb2_id_table);
 155
 156 static struct platform_driver bcm_ns_usb2_driver = {
 157         .probe          = bcm_ns_usb2_probe,
 158         .driver = {
 159                 .name = "bcm_ns_usb2",
 160                 .of_match_table = bcm_ns_usb2_id_table,
 161         },
 162 };
 163 module_platform_driver(bcm_ns_usb2_driver);
 164
 165 MODULE_LICENSE("GPL v2");