/* * Broadcom Northstar USB 2.0 PHY Driver * * Copyright (C) 2016 Rafał Miłecki <zajec5@gmail.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * */ #include <linux/bcma/bcma.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/module.h> #include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/phy/phy.h> #include <linux/platform_device.h> #include <linux/slab.h> struct bcm_ns_usb2 { struct device *dev; struct clk *ref_clk; struct phy *phy; void __iomem *dmu; }; static int bcm_ns_usb2_phy_init(struct phy *phy) { struct bcm_ns_usb2 *usb2 = phy_get_drvdata(phy); struct device *dev = usb2->dev; void __iomem *dmu = usb2->dmu; u32 ref_clk_rate, usb2ctl, usb_pll_ndiv, usb_pll_pdiv; int err = 0; err = clk_prepare_enable(usb2->ref_clk); if (err < 0) { dev_err(dev, "Failed to prepare ref clock: %d\n", err); goto err_out; } ref_clk_rate = clk_get_rate(usb2->ref_clk); if (!ref_clk_rate) { dev_err(dev, "Failed to get ref clock rate\n"); err = -EINVAL; goto err_clk_off; } usb2ctl = readl(dmu + BCMA_DMU_CRU_USB2_CONTROL); if (usb2ctl & BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK) { usb_pll_pdiv = usb2ctl; usb_pll_pdiv &= BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK; usb_pll_pdiv >>= BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_SHIFT; } else { usb_pll_pdiv = 1 << 3; } /* Calculate ndiv based on a solid 1920 MHz that is for USB2 PHY */ usb_pll_ndiv = (1920000000 * usb_pll_pdiv) / ref_clk_rate; /* Unlock DMU PLL settings with some magic value */ writel(0x0000ea68, dmu + BCMA_DMU_CRU_CLKSET_KEY); /* Write USB 2.0 PLL control setting */ usb2ctl &= ~BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_MASK; usb2ctl |= usb_pll_ndiv << BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_SHIFT; writel(usb2ctl, dmu + BCMA_DMU_CRU_USB2_CONTROL); /* Lock DMU PLL settings */ writel(0x00000000, dmu + BCMA_DMU_CRU_CLKSET_KEY); err_clk_off: clk_disable_unprepare(usb2->ref_clk); err_out: return err; } static const struct phy_ops ops = { .init = bcm_ns_usb2_phy_init, .owner = THIS_MODULE, }; static int bcm_ns_usb2_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct bcm_ns_usb2 *usb2; struct resource *res; struct phy_provider *phy_provider; usb2 = devm_kzalloc(&pdev->dev, sizeof(*usb2), GFP_KERNEL); if (!usb2) return -ENOMEM; usb2->dev = dev; res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dmu"); usb2->dmu = devm_ioremap_resource(dev, res); if (IS_ERR(usb2->dmu)) { dev_err(dev, "Failed to map DMU regs\n"); return PTR_ERR(usb2->dmu); } usb2->ref_clk = devm_clk_get(dev, "phy-ref-clk"); if (IS_ERR(usb2->ref_clk)) { dev_err(dev, "Clock not defined\n"); return PTR_ERR(usb2->ref_clk); } usb2->phy = devm_phy_create(dev, NULL, &ops); if (IS_ERR(usb2->phy)) return PTR_ERR(usb2->phy); phy_set_drvdata(usb2->phy, usb2); platform_set_drvdata(pdev, usb2); phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); return PTR_ERR_OR_ZERO(phy_provider); } static const struct of_device_id bcm_ns_usb2_id_table[] = { { .compatible = "brcm,ns-usb2-phy", }, {}, }; MODULE_DEVICE_TABLE(of, bcm_ns_usb2_id_table); static struct platform_driver bcm_ns_usb2_driver = { .probe = bcm_ns_usb2_probe, .driver = { .name = "bcm_ns_usb2", .of_match_table = bcm_ns_usb2_id_table, }, }; module_platform_driver(bcm_ns_usb2_driver); MODULE_LICENSE("GPL v2");