drivers/phy/phy-rcar-gen2.c

   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 #include <linux/atomic.h>
  21
  22 #define USBHS_LPSTS                     0x02
  23 #define USBHS_UGCTRL                    0x80
  24 #define USBHS_UGCTRL2                   0x84
  25 #define USBHS_UGSTS                     0x88    /* From technical update */
  26
  27 /* Low Power Status register (LPSTS) */
  28 #define USBHS_LPSTS_SUSPM               0x4000
  29
  30 /* USB General control register (UGCTRL) */
  31 #define USBHS_UGCTRL_CONNECT            0x00000004
  32 #define USBHS_UGCTRL_PLLRESET           0x00000001
  33
  34 /* USB General control register 2 (UGCTRL2) */
  35 #define USBHS_UGCTRL2_USB2SEL           0x80000000
  36 #define USBHS_UGCTRL2_USB2SEL_PCI       0x00000000
  37 #define USBHS_UGCTRL2_USB2SEL_USB30     0x80000000
  38 #define USBHS_UGCTRL2_USB0SEL           0x00000030
  39 #define USBHS_UGCTRL2_USB0SEL_PCI       0x00000010
  40 #define USBHS_UGCTRL2_USB0SEL_HS_USB    0x00000030
  41
  42 /* USB General status register (UGSTS) */
  43 #define USBHS_UGSTS_LOCK                0x00000100 /* From technical update */
  44
  45 #define PHYS_PER_CHANNEL        2
  46
  47 struct rcar_gen2_phy {
  48         struct phy *phy;
  49         struct rcar_gen2_channel *channel;
  50         int number;
  51         u32 select_value;
  52 };
  53
  54 struct rcar_gen2_channel {
  55         struct device_node *of_node;
  56         struct rcar_gen2_phy_driver *drv;
  57         struct rcar_gen2_phy phys[PHYS_PER_CHANNEL];
  58         int selected_phy;
  59         u32 select_mask;
  60 };
  61
  62 struct rcar_gen2_phy_driver {
  63         void __iomem *base;
  64         struct clk *clk;
  65         spinlock_t lock;
  66         int num_channels;
  67         struct rcar_gen2_channel *channels;
  68 };
  69
  70 static int rcar_gen2_phy_init(struct phy *p)
  71 {
  72         struct rcar_gen2_phy *phy = phy_get_drvdata(p);
  73         struct rcar_gen2_channel *channel = phy->channel;
  74         struct rcar_gen2_phy_driver *drv = channel->drv;
  75         unsigned long flags;
  76         u32 ugctrl2;
  77
  78         /*
  79          * Try to acquire exclusive access to PHY.  The first driver calling
  80          * phy_init()  on a given channel wins, and all attempts  to use another
  81          * PHY on this channel will fail until phy_exit() is called by the first
  82          * driver.   Achieving this with cmpxcgh() should be SMP-safe.
  83          */
  84         if (cmpxchg(&channel->selected_phy, -1, phy->number) != -1)
  85                 return -EBUSY;
  86
  87         clk_prepare_enable(drv->clk);
  88
  89         spin_lock_irqsave(&drv->lock, flags);
  90         ugctrl2 = readl(drv->base + USBHS_UGCTRL2);
  91         ugctrl2 &= ~channel->select_mask;
  92         ugctrl2 |= phy->select_value;
  93         writel(ugctrl2, drv->base + USBHS_UGCTRL2);
  94         spin_unlock_irqrestore(&drv->lock, flags);
  95         return 0;
  96 }
  97
  98 static int rcar_gen2_phy_exit(struct phy *p)
  99 {
 100         struct rcar_gen2_phy *phy = phy_get_drvdata(p);
 101         struct rcar_gen2_channel *channel = phy->channel;
 102
 103         clk_disable_unprepare(channel->drv->clk);
 104
 105         channel->selected_phy = -1;
 106
 107         return 0;
 108 }
 109
 110 static int rcar_gen2_phy_power_on(struct phy *p)
 111 {
 112         struct rcar_gen2_phy *phy = phy_get_drvdata(p);
 113         struct rcar_gen2_phy_driver *drv = phy->channel->drv;
 114         void __iomem *base = drv->base;
 115         unsigned long flags;
 116         u32 value;
 117         int err = 0, i;
 118
 119         /* Skip if it's not USBHS */
 120         if (phy->select_value != USBHS_UGCTRL2_USB0SEL_HS_USB)
 121                 return 0;
 122
 123         spin_lock_irqsave(&drv->lock, flags);
 124
 125         /* Power on USBHS PHY */
 126         value = readl(base + USBHS_UGCTRL);
 127         value &= ~USBHS_UGCTRL_PLLRESET;
 128         writel(value, base + USBHS_UGCTRL);
 129
 130         value = readw(base + USBHS_LPSTS);
 131         value |= USBHS_LPSTS_SUSPM;
 132         writew(value, base + USBHS_LPSTS);
 133
 134         for (i = 0; i < 20; i++) {
 135                 value = readl(base + USBHS_UGSTS);
 136                 if ((value & USBHS_UGSTS_LOCK) == USBHS_UGSTS_LOCK) {
 137                         value = readl(base + USBHS_UGCTRL);
 138                         value |= USBHS_UGCTRL_CONNECT;
 139                         writel(value, base + USBHS_UGCTRL);
 140                         goto out;
 141                 }
 142                 udelay(1);
 143         }
 144
 145         /* Timed out waiting for the PLL lock */
 146         err = -ETIMEDOUT;
 147
 148 out:
 149         spin_unlock_irqrestore(&drv->lock, flags);
 150
 151         return err;
 152 }
 153
 154 static int rcar_gen2_phy_power_off(struct phy *p)
 155 {
 156         struct rcar_gen2_phy *phy = phy_get_drvdata(p);
 157         struct rcar_gen2_phy_driver *drv = phy->channel->drv;
 158         void __iomem *base = drv->base;
 159         unsigned long flags;
 160         u32 value;
 161
 162         /* Skip if it's not USBHS */
 163         if (phy->select_value != USBHS_UGCTRL2_USB0SEL_HS_USB)
 164                 return 0;
 165
 166         spin_lock_irqsave(&drv->lock, flags);
 167
 168         /* Power off USBHS PHY */
 169         value = readl(base + USBHS_UGCTRL);
 170         value &= ~USBHS_UGCTRL_CONNECT;
 171         writel(value, base + USBHS_UGCTRL);
 172
 173         value = readw(base + USBHS_LPSTS);
 174         value &= ~USBHS_LPSTS_SUSPM;
 175         writew(value, base + USBHS_LPSTS);
 176
 177         value = readl(base + USBHS_UGCTRL);
 178         value |= USBHS_UGCTRL_PLLRESET;
 179         writel(value, base + USBHS_UGCTRL);
 180
 181         spin_unlock_irqrestore(&drv->lock, flags);
 182
 183         return 0;
 184 }
 185
 186 static const struct phy_ops rcar_gen2_phy_ops = {
 187         .init           = rcar_gen2_phy_init,
 188         .exit           = rcar_gen2_phy_exit,
 189         .power_on       = rcar_gen2_phy_power_on,
 190         .power_off      = rcar_gen2_phy_power_off,
 191         .owner          = THIS_MODULE,
 192 };
 193
 194 static const struct of_device_id rcar_gen2_phy_match_table[] = {
 195         { .compatible = "renesas,usb-phy-r8a7790" },
 196         { .compatible = "renesas,usb-phy-r8a7791" },
 197         { .compatible = "renesas,usb-phy-r8a7794" },
 198         { }
 199 };
 200 MODULE_DEVICE_TABLE(of, rcar_gen2_phy_match_table);
 201
 202 static 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         drv = dev_get_drvdata(dev);
 210         if (!drv)
 211                 return ERR_PTR(-EINVAL);
 212
 213         for (i = 0; i < drv->num_channels; i++) {
 214                 if (np == drv->channels[i].of_node)
 215                         break;
 216         }
 217
 218         if (i >= drv->num_channels || args->args[0] >= 2)
 219                 return ERR_PTR(-ENODEV);
 220
 221         return drv->channels[i].phys[args->args[0]].phy;
 222 }
 223
 224 static const u32 select_mask[] = {
 225         [0]     = USBHS_UGCTRL2_USB0SEL,
 226         [2]     = USBHS_UGCTRL2_USB2SEL,
 227 };
 228
 229 static const u32 select_value[][PHYS_PER_CHANNEL] = {
 230         [0]     = { USBHS_UGCTRL2_USB0SEL_PCI, USBHS_UGCTRL2_USB0SEL_HS_USB },
 231         [2]     = { USBHS_UGCTRL2_USB2SEL_PCI, USBHS_UGCTRL2_USB2SEL_USB30 },
 232 };
 233
 234 static int rcar_gen2_phy_probe(struct platform_device *pdev)
 235 {
 236         struct device *dev = &pdev->dev;
 237         struct rcar_gen2_phy_driver *drv;
 238         struct phy_provider *provider;
 239         struct device_node *np;
 240         struct resource *res;
 241         void __iomem *base;
 242         struct clk *clk;
 243         int i = 0;
 244
 245         if (!dev->of_node) {
 246                 dev_err(dev,
 247                         "This driver is required to be instantiated from device tree\n");
 248                 return -EINVAL;
 249         }
 250
 251         clk = devm_clk_get(dev, "usbhs");
 252         if (IS_ERR(clk)) {
 253                 dev_err(dev, "Can't get USBHS clock\n");
 254                 return PTR_ERR(clk);
 255         }
 256
 257         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 258         base = devm_ioremap_resource(dev, res);
 259         if (IS_ERR(base))
 260                 return PTR_ERR(base);
 261
 262         drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
 263         if (!drv)
 264                 return -ENOMEM;
 265
 266         spin_lock_init(&drv->lock);
 267
 268         drv->clk = clk;
 269         drv->base = base;
 270
 271         drv->num_channels = of_get_child_count(dev->of_node);
 272         drv->channels = devm_kcalloc(dev, drv->num_channels,
 273                                      sizeof(struct rcar_gen2_channel),
 274                                      GFP_KERNEL);
 275         if (!drv->channels)
 276                 return -ENOMEM;
 277
 278         for_each_child_of_node(dev->of_node, np) {
 279                 struct rcar_gen2_channel *channel = drv->channels + i;
 280                 u32 channel_num;
 281                 int error, n;
 282
 283                 channel->of_node = np;
 284                 channel->drv = drv;
 285                 channel->selected_phy = -1;
 286
 287                 error = of_property_read_u32(np, "reg", &channel_num);
 288                 if (error || channel_num > 2) {
 289                         dev_err(dev, "Invalid \"reg\" property\n");
 290                         return error;
 291                 }
 292                 channel->select_mask = select_mask[channel_num];
 293
 294                 for (n = 0; n < PHYS_PER_CHANNEL; n++) {
 295                         struct rcar_gen2_phy *phy = &channel->phys[n];
 296
 297                         phy->channel = channel;
 298                         phy->number = n;
 299                         phy->select_value = select_value[channel_num][n];
 300
 301                         phy->phy = devm_phy_create(dev, NULL,
 302                                                    &rcar_gen2_phy_ops);
 303                         if (IS_ERR(phy->phy)) {
 304                                 dev_err(dev, "Failed to create PHY\n");
 305                                 return PTR_ERR(phy->phy);
 306                         }
 307                         phy_set_drvdata(phy->phy, phy);
 308                 }
 309
 310                 i++;
 311         }
 312
 313         provider = devm_of_phy_provider_register(dev, rcar_gen2_phy_xlate);
 314         if (IS_ERR(provider)) {
 315                 dev_err(dev, "Failed to register PHY provider\n");
 316                 return PTR_ERR(provider);
 317         }
 318
 319         dev_set_drvdata(dev, drv);
 320
 321         return 0;
 322 }
 323
 324 static struct platform_driver rcar_gen2_phy_driver = {
 325         .driver = {
 326                 .name           = "phy_rcar_gen2",
 327                 .of_match_table = rcar_gen2_phy_match_table,
 328         },
 329         .probe  = rcar_gen2_phy_probe,
 330 };
 331
 332 module_platform_driver(rcar_gen2_phy_driver);
 333
 334 MODULE_LICENSE("GPL v2");
 335 MODULE_DESCRIPTION("Renesas R-Car Gen2 PHY");
 336 MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");