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/*
 * drivers/usb/host/ehci-oxnas.c
 *
 * Tzachi Perelstein <tzachi@marvell.com>
 *
 * This file is licensed under  the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/mfd/syscon.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/dma-mapping.h>
#include <linux/clk.h>
#include <linux/regmap.h>
#include <linux/reset.h>

#define USBHSMPH_CTRL_REGOFFSET         0x40
#define USBHSMPH_STAT_REGOFFSET         0x44
#define REF300_DIV_REGOFFSET            0xF8
#define USBHSPHY_CTRL_REGOFFSET         0x84
#define USB_CTRL_REGOFFSET              0x90
#define PLLB_DIV_CTRL_REGOFFSET         0x1000F8
#define USBHSPHY_SUSPENDM_MANUAL_ENABLE         16
#define USBHSPHY_SUSPENDM_MANUAL_STATE          15
#define USBHSPHY_ATE_ESET                       14
#define USBHSPHY_TEST_DIN                       6
#define USBHSPHY_TEST_ADD                       2
#define USBHSPHY_TEST_DOUT_SEL                  1
#define USBHSPHY_TEST_CLK                       0

#define USB_CTRL_USBAPHY_CKSEL_SHIFT    5
#define USB_CLK_XTAL0_XTAL1             (0 << USB_CTRL_USBAPHY_CKSEL_SHIFT)
#define USB_CLK_XTAL0                   (1 << USB_CTRL_USBAPHY_CKSEL_SHIFT)
#define USB_CLK_INTERNAL                (2 << USB_CTRL_USBAPHY_CKSEL_SHIFT)

#define USBAMUX_DEVICE                  BIT(4)

#define USBPHY_REFCLKDIV_SHIFT          2
#define USB_PHY_REF_12MHZ               (0 << USBPHY_REFCLKDIV_SHIFT)
#define USB_PHY_REF_24MHZ               (1 << USBPHY_REFCLKDIV_SHIFT)
#define USB_PHY_REF_48MHZ               (2 << USBPHY_REFCLKDIV_SHIFT)

#define USB_CTRL_USB_CKO_SEL_BIT        0

#define USB_INT_CLK_XTAL                0
#define USB_INT_CLK_REF300              2
#define USB_INT_CLK_PLLB                3

#define REF300_DIV_INT_SHIFT            8
#define REF300_DIV_FRAC_SHIFT           0
#define REF300_DIV_INT(val)             ((val) << REF300_DIV_INT_SHIFT)
#define REF300_DIV_FRAC(val)            ((val) << REF300_DIV_FRAC_SHIFT)

#define PLLB_BYPASS                     1
#define PLLB_ENSAT                      3
#define PLLB_OUTDIV                     4
#define PLLB_REFDIV                     8
#define PLLB_DIV_INT_SHIFT              8
#define PLLB_DIV_FRAC_SHIFT             0
#define PLLB_DIV_INT(val)               ((val) << PLLB_DIV_INT_SHIFT)
#define PLLB_DIV_FRAC(val)              ((val) << PLLB_DIV_FRAC_SHIFT)

#include "ehci.h"

struct oxnas_hcd {
        struct clk *clk;
        struct clk *refsrc;
        struct clk *phyref;
        int use_pllb;
        int use_phya;
        struct reset_control *rst_host;
        struct reset_control *rst_phya;
        struct reset_control *rst_phyb;
        struct regmap *syscon;
};

#define DRIVER_DESC "Oxnas On-Chip EHCI Host Controller"

static struct hc_driver __read_mostly oxnas_hc_driver;

static void start_oxnas_usb_ehci(struct oxnas_hcd *oxnas)
{
        if (oxnas->use_pllb) {
                /* enable pllb */
                clk_prepare_enable(oxnas->refsrc);
                /* enable ref600 */
                clk_prepare_enable(oxnas->phyref);
                /* 600MHz pllb divider for 12MHz */
                regmap_write_bits(oxnas->syscon, PLLB_DIV_CTRL_REGOFFSET, 0xffff, PLLB_DIV_INT(50) | PLLB_DIV_FRAC(0));
        } else {
                /* ref 300 divider for 12MHz */
                regmap_write_bits(oxnas->syscon, REF300_DIV_REGOFFSET, 0xffff, REF300_DIV_INT(25) | REF300_DIV_FRAC(0));
        }

        /* Ensure the USB block is properly reset */
        reset_control_reset(oxnas->rst_host);
        reset_control_reset(oxnas->rst_phya);
        reset_control_reset(oxnas->rst_phyb);

        /* Force the high speed clock to be generated all the time, via serial
         programming of the USB HS PHY */
        regmap_write_bits(oxnas->syscon, USBHSPHY_CTRL_REGOFFSET, 0xffff,
                          (2UL << USBHSPHY_TEST_ADD) |
                          (0xe0UL << USBHSPHY_TEST_DIN));

        regmap_write_bits(oxnas->syscon, USBHSPHY_CTRL_REGOFFSET, 0xffff,
                          (1UL << USBHSPHY_TEST_CLK) |
                          (2UL << USBHSPHY_TEST_ADD) |
                          (0xe0UL << USBHSPHY_TEST_DIN));

        regmap_write_bits(oxnas->syscon, USBHSPHY_CTRL_REGOFFSET, 0xffff,
                          (0xfUL << USBHSPHY_TEST_ADD) |
                          (0xaaUL << USBHSPHY_TEST_DIN));

        regmap_write_bits(oxnas->syscon, USBHSPHY_CTRL_REGOFFSET, 0xffff,
                          (1UL << USBHSPHY_TEST_CLK) |
                          (0xfUL << USBHSPHY_TEST_ADD) |
                          (0xaaUL << USBHSPHY_TEST_DIN));

        if (oxnas->use_pllb) /* use pllb clock */
                regmap_write_bits(oxnas->syscon, USB_CTRL_REGOFFSET, 0xffff,
                                  USB_CLK_INTERNAL | USB_INT_CLK_PLLB);
        else /* use ref300 derived clock */
                regmap_write_bits(oxnas->syscon, USB_CTRL_REGOFFSET, 0xffff,
                                  USB_CLK_INTERNAL | USB_INT_CLK_REF300);

        if (oxnas->use_phya) {
                /* Configure USB PHYA as a host */
                regmap_update_bits(oxnas->syscon, USB_CTRL_REGOFFSET, USBAMUX_DEVICE, 0);
        }

        /* Enable the clock to the USB block */
        clk_prepare_enable(oxnas->clk);
}

static void stop_oxnas_usb_ehci(struct oxnas_hcd *oxnas)
{
        reset_control_assert(oxnas->rst_host);
        reset_control_assert(oxnas->rst_phya);
        reset_control_assert(oxnas->rst_phyb);

        if (oxnas->use_pllb) {
                clk_disable_unprepare(oxnas->phyref);
                clk_disable_unprepare(oxnas->refsrc);
        }
        clk_disable_unprepare(oxnas->clk);
}

static int ehci_oxnas_reset(struct usb_hcd *hcd)
{
        #define  txttfill_tuning        reserved2[0]

        struct ehci_hcd *ehci;
        u32 tmp;
        int retval = ehci_setup(hcd);
        if (retval)
                return retval;

        ehci = hcd_to_ehci(hcd);
        tmp = ehci_readl(ehci, &ehci->regs->txfill_tuning);
        tmp &= ~0x00ff0000;
        tmp |= 0x003f0000; /* set burst pre load count to 0x40 (63 * 4 bytes)  */
        tmp |= 0x16; /* set sheduler overhead to 22 * 1.267us (HS) or 22 * 6.33us (FS/LS)*/
        ehci_writel(ehci, tmp,  &ehci->regs->txfill_tuning);

        tmp = ehci_readl(ehci, &ehci->regs->txttfill_tuning);
        tmp |= 0x2; /* set sheduler overhead to 2 * 6.333us */
        ehci_writel(ehci, tmp,  &ehci->regs->txttfill_tuning);

        return retval;
}

static int ehci_oxnas_drv_probe(struct platform_device *ofdev)
{
        struct device_node *np = ofdev->dev.of_node;
        struct usb_hcd *hcd;
        struct ehci_hcd *ehci;
        struct resource res;
        struct oxnas_hcd *oxnas;
        int irq, err;
        struct reset_control *rstc;

        if (usb_disabled())
                return -ENODEV;

        if (!ofdev->dev.dma_mask)
                ofdev->dev.dma_mask = &ofdev->dev.coherent_dma_mask;
        if (!ofdev->dev.coherent_dma_mask)
                ofdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);

        hcd = usb_create_hcd(&oxnas_hc_driver,  &ofdev->dev,
                                        dev_name(&ofdev->dev));
        if (!hcd)
                return -ENOMEM;

        err = of_address_to_resource(np, 0, &res);
        if (err)
                goto err_res;

        hcd->rsrc_start = res.start;
        hcd->rsrc_len = resource_size(&res);

        hcd->regs = devm_ioremap_resource(&ofdev->dev, &res);
        if (IS_ERR(hcd->regs)) {
                dev_err(&ofdev->dev, "devm_ioremap_resource failed\n");
                err = PTR_ERR(hcd->regs);
                goto err_ioremap;
        }

        oxnas = (struct oxnas_hcd *)hcd_to_ehci(hcd)->priv;

        oxnas->use_pllb = of_property_read_bool(np, "oxsemi,ehci_use_pllb");
        oxnas->use_phya = of_property_read_bool(np, "oxsemi,ehci_use_phya");

        oxnas->syscon = syscon_regmap_lookup_by_phandle(np, "oxsemi,sys-ctrl");
        if (IS_ERR(oxnas->syscon)) {
                err = PTR_ERR(oxnas->syscon);
                goto err_syscon;
        }

        oxnas->clk = of_clk_get_by_name(np, "usb");
        if (IS_ERR(oxnas->clk)) {
                err = PTR_ERR(oxnas->clk);
                goto err_clk;
        }

        if (oxnas->use_pllb) {
                oxnas->refsrc = of_clk_get_by_name(np, "refsrc");
                if (IS_ERR(oxnas->refsrc)) {
                        err = PTR_ERR(oxnas->refsrc);
                        goto err_refsrc;
                }
                oxnas->phyref = of_clk_get_by_name(np, "phyref");
                if (IS_ERR(oxnas->refsrc)) {
                        err = PTR_ERR(oxnas->refsrc);
                        goto err_phyref;
                }

        } else {
                oxnas->refsrc = NULL;
                oxnas->phyref = NULL;
        }

        rstc = devm_reset_control_get(&ofdev->dev, "host");
        if (IS_ERR(rstc)) {
                err = PTR_ERR(rstc);
                goto err_rst;
        }
        oxnas->rst_host = rstc;

        rstc = devm_reset_control_get(&ofdev->dev, "phya");
        if (IS_ERR(rstc)) {
                err = PTR_ERR(rstc);
                goto err_rst;
        }
        oxnas->rst_phya = rstc;

        rstc = devm_reset_control_get(&ofdev->dev, "phyb");
        if (IS_ERR(rstc)) {
                err = PTR_ERR(rstc);
                goto err_rst;
        }
        oxnas->rst_phyb = rstc;

        irq = irq_of_parse_and_map(np, 0);
        if (!irq) {
                dev_err(&ofdev->dev, "irq_of_parse_and_map failed\n");
                err = -EBUSY;
                goto err_irq;
        }

        hcd->has_tt = 1;
        ehci = hcd_to_ehci(hcd);
        ehci->caps = hcd->regs;

        start_oxnas_usb_ehci(oxnas);

        err = usb_add_hcd(hcd, irq, IRQF_SHARED);
        if (err)
                goto err_hcd;

        return 0;

err_hcd:
        stop_oxnas_usb_ehci(oxnas);
err_irq:
err_rst:
        if (oxnas->phyref)
                clk_put(oxnas->phyref);
err_phyref:
        if (oxnas->refsrc)
                clk_put(oxnas->refsrc);
err_refsrc:
        clk_put(oxnas->clk);
err_syscon:
err_clk:
err_ioremap:
err_res:
        usb_put_hcd(hcd);

        return err;
}

static int ehci_oxnas_drv_remove(struct platform_device *pdev)
{
        struct usb_hcd *hcd = platform_get_drvdata(pdev);
        struct oxnas_hcd *oxnas = (struct oxnas_hcd *)hcd_to_ehci(hcd)->priv;

        usb_remove_hcd(hcd);
        if (oxnas->use_pllb) {
                clk_disable_unprepare(oxnas->phyref);
                clk_put(oxnas->phyref);
                clk_disable_unprepare(oxnas->refsrc);
                clk_put(oxnas->refsrc);
        }
        clk_disable_unprepare(oxnas->clk);
        usb_put_hcd(hcd);

        return 0;
}

static const struct of_device_id oxnas_ehci_dt_ids[] = {
        { .compatible = "plxtech,nas782x-ehci" },
        { /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, oxnas_ehci_dt_ids);

static struct platform_driver ehci_oxnas_driver = {
        .probe          = ehci_oxnas_drv_probe,
        .remove         = ehci_oxnas_drv_remove,
        .shutdown       = usb_hcd_platform_shutdown,
        .driver.name    = "oxnas-ehci",
        .driver.of_match_table  = oxnas_ehci_dt_ids,
};

static const struct ehci_driver_overrides oxnas_overrides __initconst = {
        .reset = ehci_oxnas_reset,
        .extra_priv_size = sizeof(struct oxnas_hcd),
};

static int __init ehci_oxnas_init(void)
{
        if (usb_disabled())
                return -ENODEV;

        ehci_init_driver(&oxnas_hc_driver, &oxnas_overrides);
        return platform_driver_register(&ehci_oxnas_driver);
}
module_init(ehci_oxnas_init);

static void __exit ehci_oxnas_cleanup(void)
{
        platform_driver_unregister(&ehci_oxnas_driver);
}
module_exit(ehci_oxnas_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_ALIAS("platform:oxnas-ehci");
MODULE_LICENSE("GPL");