drivers/net/phy/mdio-mux-bcm-iproc.c

   1 /*
   2  * Copyright 2016 Broadcom
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2, as
   6  * published by the Free Software Foundation (the "GPL").
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License version 2 (GPLv2) for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * version 2 (GPLv2) along with this source code.
  15  */
  16
  17 #include <linux/platform_device.h>
  18 #include <linux/device.h>
  19 #include <linux/of_mdio.h>
  20 #include <linux/module.h>
  21 #include <linux/phy.h>
  22 #include <linux/mdio-mux.h>
  23 #include <linux/delay.h>
  24
  25 #define MDIO_PARAM_OFFSET               0x00
  26 #define MDIO_PARAM_MIIM_CYCLE           29
  27 #define MDIO_PARAM_INTERNAL_SEL         25
  28 #define MDIO_PARAM_BUS_ID               22
  29 #define MDIO_PARAM_C45_SEL              21
  30 #define MDIO_PARAM_PHY_ID               16
  31 #define MDIO_PARAM_PHY_DATA             0
  32
  33 #define MDIO_READ_OFFSET                0x04
  34 #define MDIO_READ_DATA_MASK             0xffff
  35 #define MDIO_ADDR_OFFSET                0x08
  36
  37 #define MDIO_CTRL_OFFSET                0x0C
  38 #define MDIO_CTRL_WRITE_OP              0x1
  39 #define MDIO_CTRL_READ_OP               0x2
  40
  41 #define MDIO_STAT_OFFSET                0x10
  42 #define MDIO_STAT_DONE                  1
  43
  44 #define BUS_MAX_ADDR                    32
  45 #define EXT_BUS_START_ADDR              16
  46
  47 struct iproc_mdiomux_desc {
  48         void *mux_handle;
  49         void __iomem *base;
  50         struct device *dev;
  51         struct mii_bus *mii_bus;
  52 };
  53
  54 static int iproc_mdio_wait_for_idle(void __iomem *base, bool result)
  55 {
  56         unsigned int timeout = 1000; /* loop for 1s */
  57         u32 val;
  58
  59         do {
  60                 val = readl(base + MDIO_STAT_OFFSET);
  61                 if ((val & MDIO_STAT_DONE) == result)
  62                         return 0;
  63
  64                 usleep_range(1000, 2000);
  65         } while (timeout--);
  66
  67         return -ETIMEDOUT;
  68 }
  69
  70 /* start_miim_ops- Program and start MDIO transaction over mdio bus.
  71  * @base: Base address
  72  * @phyid: phyid of the selected bus.
  73  * @reg: register offset to be read/written.
  74  * @val :0 if read op else value to be written in @reg;
  75  * @op: Operation that need to be carried out.
  76  *      MDIO_CTRL_READ_OP: Read transaction.
  77  *      MDIO_CTRL_WRITE_OP: Write transaction.
  78  *
  79  * Return value: Successful Read operation returns read reg values and write
  80  *      operation returns 0. Failure operation returns negative error code.
  81  */
  82 static int start_miim_ops(void __iomem *base,
  83                           u16 phyid, u32 reg, u16 val, u32 op)
  84 {
  85         u32 param;
  86         int ret;
  87
  88         writel(0, base + MDIO_CTRL_OFFSET);
  89         ret = iproc_mdio_wait_for_idle(base, 0);
  90         if (ret)
  91                 goto err;
  92
  93         param = readl(base + MDIO_PARAM_OFFSET);
  94         param |= phyid << MDIO_PARAM_PHY_ID;
  95         param |= val << MDIO_PARAM_PHY_DATA;
  96         if (reg & MII_ADDR_C45)
  97                 param |= BIT(MDIO_PARAM_C45_SEL);
  98
  99         writel(param, base + MDIO_PARAM_OFFSET);
 100
 101         writel(reg, base + MDIO_ADDR_OFFSET);
 102
 103         writel(op, base + MDIO_CTRL_OFFSET);
 104
 105         ret = iproc_mdio_wait_for_idle(base, 1);
 106         if (ret)
 107                 goto err;
 108
 109         if (op == MDIO_CTRL_READ_OP)
 110                 ret = readl(base + MDIO_READ_OFFSET) & MDIO_READ_DATA_MASK;
 111 err:
 112         return ret;
 113 }
 114
 115 static int iproc_mdiomux_read(struct mii_bus *bus, int phyid, int reg)
 116 {
 117         struct iproc_mdiomux_desc *md = bus->priv;
 118         int ret;
 119
 120         ret = start_miim_ops(md->base, phyid, reg, 0, MDIO_CTRL_READ_OP);
 121         if (ret < 0)
 122                 dev_err(&bus->dev, "mdiomux read operation failed!!!");
 123
 124         return ret;
 125 }
 126
 127 static int iproc_mdiomux_write(struct mii_bus *bus,
 128                                int phyid, int reg, u16 val)
 129 {
 130         struct iproc_mdiomux_desc *md = bus->priv;
 131         int ret;
 132
 133         /* Write val at reg offset */
 134         ret = start_miim_ops(md->base, phyid, reg, val, MDIO_CTRL_WRITE_OP);
 135         if (ret < 0)
 136                 dev_err(&bus->dev, "mdiomux write operation failed!!!");
 137
 138         return ret;
 139 }
 140
 141 static int mdio_mux_iproc_switch_fn(int current_child, int desired_child,
 142                                     void *data)
 143 {
 144         struct iproc_mdiomux_desc *md = data;
 145         u32 param, bus_id;
 146         bool bus_dir;
 147
 148         /* select bus and its properties */
 149         bus_dir = (desired_child < EXT_BUS_START_ADDR);
 150         bus_id = bus_dir ? desired_child : (desired_child - EXT_BUS_START_ADDR);
 151
 152         param = (bus_dir ? 1 : 0) << MDIO_PARAM_INTERNAL_SEL;
 153         param |= (bus_id << MDIO_PARAM_BUS_ID);
 154
 155         writel(param, md->base + MDIO_PARAM_OFFSET);
 156         return 0;
 157 }
 158
 159 static int mdio_mux_iproc_probe(struct platform_device *pdev)
 160 {
 161         struct iproc_mdiomux_desc *md;
 162         struct mii_bus *bus;
 163         struct resource *res;
 164         int rc;
 165
 166         md = devm_kzalloc(&pdev->dev, sizeof(*md), GFP_KERNEL);
 167         if (!md)
 168                 return -ENOMEM;
 169         md->dev = &pdev->dev;
 170
 171         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 172         md->base = devm_ioremap_resource(&pdev->dev, res);
 173         if (IS_ERR(md->base)) {
 174                 dev_err(&pdev->dev, "failed to ioremap register\n");
 175                 return PTR_ERR(md->base);
 176         }
 177
 178         md->mii_bus = mdiobus_alloc();
 179         if (!md->mii_bus) {
 180                 dev_err(&pdev->dev, "mdiomux bus alloc failed\n");
 181                 return -ENOMEM;
 182         }
 183
 184         bus = md->mii_bus;
 185         bus->priv = md;
 186         bus->name = "iProc MDIO mux bus";
 187         snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id);
 188         bus->parent = &pdev->dev;
 189         bus->read = iproc_mdiomux_read;
 190         bus->write = iproc_mdiomux_write;
 191
 192         bus->phy_mask = ~0;
 193         bus->dev.of_node = pdev->dev.of_node;
 194         rc = mdiobus_register(bus);
 195         if (rc) {
 196                 dev_err(&pdev->dev, "mdiomux registration failed\n");
 197                 goto out;
 198         }
 199
 200         platform_set_drvdata(pdev, md);
 201
 202         rc = mdio_mux_init(md->dev, mdio_mux_iproc_switch_fn,
 203                            &md->mux_handle, md, md->mii_bus);
 204         if (rc) {
 205                 dev_info(md->dev, "mdiomux initialization failed\n");
 206                 goto out;
 207         }
 208
 209         dev_info(md->dev, "iProc mdiomux registered\n");
 210         return 0;
 211 out:
 212         mdiobus_free(bus);
 213         return rc;
 214 }
 215
 216 static int mdio_mux_iproc_remove(struct platform_device *pdev)
 217 {
 218         struct iproc_mdiomux_desc *md = dev_get_platdata(&pdev->dev);
 219
 220         mdio_mux_uninit(md->mux_handle);
 221         mdiobus_unregister(md->mii_bus);
 222         mdiobus_free(md->mii_bus);
 223
 224         return 0;
 225 }
 226
 227 static const struct of_device_id mdio_mux_iproc_match[] = {
 228         {
 229                 .compatible = "brcm,mdio-mux-iproc",
 230         },
 231         {},
 232 };
 233 MODULE_DEVICE_TABLE(of, mdio_mux_iproc_match);
 234
 235 static struct platform_driver mdiomux_iproc_driver = {
 236         .driver = {
 237                 .name           = "mdio-mux-iproc",
 238                 .of_match_table = mdio_mux_iproc_match,
 239         },
 240         .probe          = mdio_mux_iproc_probe,
 241         .remove         = mdio_mux_iproc_remove,
 242 };
 243
 244 module_platform_driver(mdiomux_iproc_driver);
 245
 246 MODULE_DESCRIPTION("iProc MDIO Mux Bus Driver");
 247 MODULE_AUTHOR("Pramod Kumar <pramod.kumar@broadcom.com>");
 248 MODULE_LICENSE("GPL v2");