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/*
* 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");
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