linux/drivers/phy/phy-rcar-gen2.c
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   1/*
   2 * Renesas R-Car Gen2 PHY driver
   3 *
   4 * Copyright (C) 2014 Renesas Solutions Corp.
   5 * Copyright (C) 2014 Cogent Embedded, Inc.
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 */
  11
  12#include <linux/clk.h>
  13#include <linux/delay.h>
  14#include <linux/io.h>
  15#include <linux/module.h>
  16#include <linux/of.h>
  17#include <linux/phy/phy.h>
  18#include <linux/platform_device.h>
  19#include <linux/spinlock.h>
  20
  21#include <asm/cmpxchg.h>
  22
  23#define USBHS_LPSTS                     0x02
  24#define USBHS_UGCTRL                    0x80
  25#define USBHS_UGCTRL2                   0x84
  26#define USBHS_UGSTS                     0x88    /* From technical update */
  27
  28/* Low Power Status register (LPSTS) */
  29#define USBHS_LPSTS_SUSPM               0x4000
  30
  31/* USB General control register (UGCTRL) */
  32#define USBHS_UGCTRL_CONNECT            0x00000004
  33#define USBHS_UGCTRL_PLLRESET           0x00000001
  34
  35/* USB General control register 2 (UGCTRL2) */
  36#define USBHS_UGCTRL2_USB2SEL           0x80000000
  37#define USBHS_UGCTRL2_USB2SEL_PCI       0x00000000
  38#define USBHS_UGCTRL2_USB2SEL_USB30     0x80000000
  39#define USBHS_UGCTRL2_USB0SEL           0x00000030
  40#define USBHS_UGCTRL2_USB0SEL_PCI       0x00000010
  41#define USBHS_UGCTRL2_USB0SEL_HS_USB    0x00000030
  42
  43/* USB General status register (UGSTS) */
  44#define USBHS_UGSTS_LOCK                0x00000100 /* From technical update */
  45
  46#define PHYS_PER_CHANNEL        2
  47
  48struct rcar_gen2_phy {
  49        struct phy *phy;
  50        struct rcar_gen2_channel *channel;
  51        int number;
  52        u32 select_value;
  53};
  54
  55struct rcar_gen2_channel {
  56        struct device_node *of_node;
  57        struct rcar_gen2_phy_driver *drv;
  58        struct rcar_gen2_phy phys[PHYS_PER_CHANNEL];
  59        int selected_phy;
  60        u32 select_mask;
  61};
  62
  63struct rcar_gen2_phy_driver {
  64        void __iomem *base;
  65        struct clk *clk;
  66        spinlock_t lock;
  67        int num_channels;
  68        struct rcar_gen2_channel *channels;
  69};
  70
  71static int rcar_gen2_phy_init(struct phy *p)
  72{
  73        struct rcar_gen2_phy *phy = phy_get_drvdata(p);
  74        struct rcar_gen2_channel *channel = phy->channel;
  75        struct rcar_gen2_phy_driver *drv = channel->drv;
  76        unsigned long flags;
  77        u32 ugctrl2;
  78
  79        /*
  80         * Try to acquire exclusive access to PHY.  The first driver calling
  81         * phy_init()  on a given channel wins, and all attempts  to use another
  82         * PHY on this channel will fail until phy_exit() is called by the first
  83         * driver.   Achieving this with cmpxcgh() should be SMP-safe.
  84         */
  85        if (cmpxchg(&channel->selected_phy, -1, phy->number) != -1)
  86                return -EBUSY;
  87
  88        clk_prepare_enable(drv->clk);
  89
  90        spin_lock_irqsave(&drv->lock, flags);
  91        ugctrl2 = readl(drv->base + USBHS_UGCTRL2);
  92        ugctrl2 &= ~channel->select_mask;
  93        ugctrl2 |= phy->select_value;
  94        writel(ugctrl2, drv->base + USBHS_UGCTRL2);
  95        spin_unlock_irqrestore(&drv->lock, flags);
  96        return 0;
  97}
  98
  99static int rcar_gen2_phy_exit(struct phy *p)
 100{
 101        struct rcar_gen2_phy *phy = phy_get_drvdata(p);
 102        struct rcar_gen2_channel *channel = phy->channel;
 103
 104        clk_disable_unprepare(channel->drv->clk);
 105
 106        channel->selected_phy = -1;
 107
 108        return 0;
 109}
 110
 111static int rcar_gen2_phy_power_on(struct phy *p)
 112{
 113        struct rcar_gen2_phy *phy = phy_get_drvdata(p);
 114        struct rcar_gen2_phy_driver *drv = phy->channel->drv;
 115        void __iomem *base = drv->base;
 116        unsigned long flags;
 117        u32 value;
 118        int err = 0, i;
 119
 120        /* Skip if it's not USBHS */
 121        if (phy->select_value != USBHS_UGCTRL2_USB0SEL_HS_USB)
 122                return 0;
 123
 124        spin_lock_irqsave(&drv->lock, flags);
 125
 126        /* Power on USBHS PHY */
 127        value = readl(base + USBHS_UGCTRL);
 128        value &= ~USBHS_UGCTRL_PLLRESET;
 129        writel(value, base + USBHS_UGCTRL);
 130
 131        value = readw(base + USBHS_LPSTS);
 132        value |= USBHS_LPSTS_SUSPM;
 133        writew(value, base + USBHS_LPSTS);
 134
 135        for (i = 0; i < 20; i++) {
 136                value = readl(base + USBHS_UGSTS);
 137                if ((value & USBHS_UGSTS_LOCK) == USBHS_UGSTS_LOCK) {
 138                        value = readl(base + USBHS_UGCTRL);
 139                        value |= USBHS_UGCTRL_CONNECT;
 140                        writel(value, base + USBHS_UGCTRL);
 141                        goto out;
 142                }
 143                udelay(1);
 144        }
 145
 146        /* Timed out waiting for the PLL lock */
 147        err = -ETIMEDOUT;
 148
 149out:
 150        spin_unlock_irqrestore(&drv->lock, flags);
 151
 152        return err;
 153}
 154
 155static int rcar_gen2_phy_power_off(struct phy *p)
 156{
 157        struct rcar_gen2_phy *phy = phy_get_drvdata(p);
 158        struct rcar_gen2_phy_driver *drv = phy->channel->drv;
 159        void __iomem *base = drv->base;
 160        unsigned long flags;
 161        u32 value;
 162
 163        /* Skip if it's not USBHS */
 164        if (phy->select_value != USBHS_UGCTRL2_USB0SEL_HS_USB)
 165                return 0;
 166
 167        spin_lock_irqsave(&drv->lock, flags);
 168
 169        /* Power off USBHS PHY */
 170        value = readl(base + USBHS_UGCTRL);
 171        value &= ~USBHS_UGCTRL_CONNECT;
 172        writel(value, base + USBHS_UGCTRL);
 173
 174        value = readw(base + USBHS_LPSTS);
 175        value &= ~USBHS_LPSTS_SUSPM;
 176        writew(value, base + USBHS_LPSTS);
 177
 178        value = readl(base + USBHS_UGCTRL);
 179        value |= USBHS_UGCTRL_PLLRESET;
 180        writel(value, base + USBHS_UGCTRL);
 181
 182        spin_unlock_irqrestore(&drv->lock, flags);
 183
 184        return 0;
 185}
 186
 187static struct phy_ops rcar_gen2_phy_ops = {
 188        .init           = rcar_gen2_phy_init,
 189        .exit           = rcar_gen2_phy_exit,
 190        .power_on       = rcar_gen2_phy_power_on,
 191        .power_off      = rcar_gen2_phy_power_off,
 192        .owner          = THIS_MODULE,
 193};
 194
 195static const struct of_device_id rcar_gen2_phy_match_table[] = {
 196        { .compatible = "renesas,usb-phy-r8a7790" },
 197        { .compatible = "renesas,usb-phy-r8a7791" },
 198        { }
 199};
 200MODULE_DEVICE_TABLE(of, rcar_gen2_phy_match_table);
 201
 202static struct phy *rcar_gen2_phy_xlate(struct device *dev,
 203                                       struct of_phandle_args *args)
 204{
 205        struct rcar_gen2_phy_driver *drv;
 206        struct device_node *np = args->np;
 207        int i;
 208
 209        if (!of_device_is_available(np)) {
 210                dev_warn(dev, "Requested PHY is disabled\n");
 211                return ERR_PTR(-ENODEV);
 212        }
 213
 214        drv = dev_get_drvdata(dev);
 215        if (!drv)
 216                return ERR_PTR(-EINVAL);
 217
 218        for (i = 0; i < drv->num_channels; i++) {
 219                if (np == drv->channels[i].of_node)
 220                        break;
 221        }
 222
 223        if (i >= drv->num_channels || args->args[0] >= 2)
 224                return ERR_PTR(-ENODEV);
 225
 226        return drv->channels[i].phys[args->args[0]].phy;
 227}
 228
 229static const u32 select_mask[] = {
 230        [0]     = USBHS_UGCTRL2_USB0SEL,
 231        [2]     = USBHS_UGCTRL2_USB2SEL,
 232};
 233
 234static const u32 select_value[][PHYS_PER_CHANNEL] = {
 235        [0]     = { USBHS_UGCTRL2_USB0SEL_PCI, USBHS_UGCTRL2_USB0SEL_HS_USB },
 236        [2]     = { USBHS_UGCTRL2_USB2SEL_PCI, USBHS_UGCTRL2_USB2SEL_USB30 },
 237};
 238
 239static int rcar_gen2_phy_probe(struct platform_device *pdev)
 240{
 241        struct device *dev = &pdev->dev;
 242        struct rcar_gen2_phy_driver *drv;
 243        struct phy_provider *provider;
 244        struct device_node *np;
 245        struct resource *res;
 246        void __iomem *base;
 247        struct clk *clk;
 248        int i = 0;
 249
 250        if (!dev->of_node) {
 251                dev_err(dev,
 252                        "This driver is required to be instantiated from device tree\n");
 253                return -EINVAL;
 254        }
 255
 256        clk = devm_clk_get(dev, "usbhs");
 257        if (IS_ERR(clk)) {
 258                dev_err(dev, "Can't get USBHS clock\n");
 259                return PTR_ERR(clk);
 260        }
 261
 262        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 263        base = devm_ioremap_resource(dev, res);
 264        if (IS_ERR(base))
 265                return PTR_ERR(base);
 266
 267        drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
 268        if (!drv)
 269                return -ENOMEM;
 270
 271        spin_lock_init(&drv->lock);
 272
 273        drv->clk = clk;
 274        drv->base = base;
 275
 276        drv->num_channels = of_get_child_count(dev->of_node);
 277        drv->channels = devm_kcalloc(dev, drv->num_channels,
 278                                     sizeof(struct rcar_gen2_channel),
 279                                     GFP_KERNEL);
 280        if (!drv->channels)
 281                return -ENOMEM;
 282
 283        for_each_child_of_node(dev->of_node, np) {
 284                struct rcar_gen2_channel *channel = drv->channels + i;
 285                u32 channel_num;
 286                int error, n;
 287
 288                channel->of_node = np;
 289                channel->drv = drv;
 290                channel->selected_phy = -1;
 291
 292                error = of_property_read_u32(np, "reg", &channel_num);
 293                if (error || channel_num > 2) {
 294                        dev_err(dev, "Invalid \"reg\" property\n");
 295                        return error;
 296                }
 297                channel->select_mask = select_mask[channel_num];
 298
 299                for (n = 0; n < PHYS_PER_CHANNEL; n++) {
 300                        struct rcar_gen2_phy *phy = &channel->phys[n];
 301
 302                        phy->channel = channel;
 303                        phy->number = n;
 304                        phy->select_value = select_value[channel_num][n];
 305
 306                        phy->phy = devm_phy_create(dev, NULL,
 307                                                   &rcar_gen2_phy_ops);
 308                        if (IS_ERR(phy->phy)) {
 309                                dev_err(dev, "Failed to create PHY\n");
 310                                return PTR_ERR(phy->phy);
 311                        }
 312                        phy_set_drvdata(phy->phy, phy);
 313                }
 314
 315                i++;
 316        }
 317
 318        provider = devm_of_phy_provider_register(dev, rcar_gen2_phy_xlate);
 319        if (IS_ERR(provider)) {
 320                dev_err(dev, "Failed to register PHY provider\n");
 321                return PTR_ERR(provider);
 322        }
 323
 324        dev_set_drvdata(dev, drv);
 325
 326        return 0;
 327}
 328
 329static struct platform_driver rcar_gen2_phy_driver = {
 330        .driver = {
 331                .name           = "phy_rcar_gen2",
 332                .of_match_table = rcar_gen2_phy_match_table,
 333        },
 334        .probe  = rcar_gen2_phy_probe,
 335};
 336
 337module_platform_driver(rcar_gen2_phy_driver);
 338
 339MODULE_LICENSE("GPL v2");
 340MODULE_DESCRIPTION("Renesas R-Car Gen2 PHY");
 341MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
 342