2 * Copyright 2016 Broadcom
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").
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.
13 * You should have received a copy of the GNU General Public License
14 * version 2 (GPLv2) along with this source code.
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>
25 #define MDIO_SCAN_CTRL_OFFSET 0x008
26 #define MDIO_SCAN_CTRL_OVRIDE_EXT_MSTR 28
28 #define MDIO_PARAM_OFFSET 0x23c
29 #define MDIO_PARAM_MIIM_CYCLE 29
30 #define MDIO_PARAM_INTERNAL_SEL 25
31 #define MDIO_PARAM_BUS_ID 22
32 #define MDIO_PARAM_C45_SEL 21
33 #define MDIO_PARAM_PHY_ID 16
34 #define MDIO_PARAM_PHY_DATA 0
36 #define MDIO_READ_OFFSET 0x240
37 #define MDIO_READ_DATA_MASK 0xffff
38 #define MDIO_ADDR_OFFSET 0x244
40 #define MDIO_CTRL_OFFSET 0x248
41 #define MDIO_CTRL_WRITE_OP 0x1
42 #define MDIO_CTRL_READ_OP 0x2
44 #define MDIO_STAT_OFFSET 0x24c
45 #define MDIO_STAT_DONE 1
47 #define BUS_MAX_ADDR 32
48 #define EXT_BUS_START_ADDR 16
50 #define MDIO_REG_ADDR_SPACE_SIZE 0x250
52 struct iproc_mdiomux_desc {
56 struct mii_bus *mii_bus;
59 static void mdio_mux_iproc_config(struct iproc_mdiomux_desc *md)
63 /* Disable external mdio master access */
64 val = readl(md->base + MDIO_SCAN_CTRL_OFFSET);
65 val |= BIT(MDIO_SCAN_CTRL_OVRIDE_EXT_MSTR);
66 writel(val, md->base + MDIO_SCAN_CTRL_OFFSET);
69 static int iproc_mdio_wait_for_idle(void __iomem *base, bool result)
71 unsigned int timeout = 1000; /* loop for 1s */
75 val = readl(base + MDIO_STAT_OFFSET);
76 if ((val & MDIO_STAT_DONE) == result)
79 usleep_range(1000, 2000);
85 /* start_miim_ops- Program and start MDIO transaction over mdio bus.
87 * @phyid: phyid of the selected bus.
88 * @reg: register offset to be read/written.
89 * @val :0 if read op else value to be written in @reg;
90 * @op: Operation that need to be carried out.
91 * MDIO_CTRL_READ_OP: Read transaction.
92 * MDIO_CTRL_WRITE_OP: Write transaction.
94 * Return value: Successful Read operation returns read reg values and write
95 * operation returns 0. Failure operation returns negative error code.
97 static int start_miim_ops(void __iomem *base,
98 u16 phyid, u32 reg, u16 val, u32 op)
103 writel(0, base + MDIO_CTRL_OFFSET);
104 ret = iproc_mdio_wait_for_idle(base, 0);
108 param = readl(base + MDIO_PARAM_OFFSET);
109 param |= phyid << MDIO_PARAM_PHY_ID;
110 param |= val << MDIO_PARAM_PHY_DATA;
111 if (reg & MII_ADDR_C45)
112 param |= BIT(MDIO_PARAM_C45_SEL);
114 writel(param, base + MDIO_PARAM_OFFSET);
116 writel(reg, base + MDIO_ADDR_OFFSET);
118 writel(op, base + MDIO_CTRL_OFFSET);
120 ret = iproc_mdio_wait_for_idle(base, 1);
124 if (op == MDIO_CTRL_READ_OP)
125 ret = readl(base + MDIO_READ_OFFSET) & MDIO_READ_DATA_MASK;
130 static int iproc_mdiomux_read(struct mii_bus *bus, int phyid, int reg)
132 struct iproc_mdiomux_desc *md = bus->priv;
135 ret = start_miim_ops(md->base, phyid, reg, 0, MDIO_CTRL_READ_OP);
137 dev_err(&bus->dev, "mdiomux read operation failed!!!");
142 static int iproc_mdiomux_write(struct mii_bus *bus,
143 int phyid, int reg, u16 val)
145 struct iproc_mdiomux_desc *md = bus->priv;
148 /* Write val at reg offset */
149 ret = start_miim_ops(md->base, phyid, reg, val, MDIO_CTRL_WRITE_OP);
151 dev_err(&bus->dev, "mdiomux write operation failed!!!");
156 static int mdio_mux_iproc_switch_fn(int current_child, int desired_child,
159 struct iproc_mdiomux_desc *md = data;
163 /* select bus and its properties */
164 bus_dir = (desired_child < EXT_BUS_START_ADDR);
165 bus_id = bus_dir ? desired_child : (desired_child - EXT_BUS_START_ADDR);
167 param = (bus_dir ? 1 : 0) << MDIO_PARAM_INTERNAL_SEL;
168 param |= (bus_id << MDIO_PARAM_BUS_ID);
170 writel(param, md->base + MDIO_PARAM_OFFSET);
174 static int mdio_mux_iproc_probe(struct platform_device *pdev)
176 struct iproc_mdiomux_desc *md;
178 struct resource *res;
181 md = devm_kzalloc(&pdev->dev, sizeof(*md), GFP_KERNEL);
184 md->dev = &pdev->dev;
186 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
187 if (res->start & 0xfff) {
188 /* For backward compatibility in case the
189 * base address is specified with an offset.
191 dev_info(&pdev->dev, "fix base address in dt-blob\n");
192 res->start &= ~0xfff;
193 res->end = res->start + MDIO_REG_ADDR_SPACE_SIZE - 1;
195 md->base = devm_ioremap_resource(&pdev->dev, res);
196 if (IS_ERR(md->base)) {
197 dev_err(&pdev->dev, "failed to ioremap register\n");
198 return PTR_ERR(md->base);
201 md->mii_bus = mdiobus_alloc();
203 dev_err(&pdev->dev, "mdiomux bus alloc failed\n");
209 bus->name = "iProc MDIO mux bus";
210 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id);
211 bus->parent = &pdev->dev;
212 bus->read = iproc_mdiomux_read;
213 bus->write = iproc_mdiomux_write;
216 bus->dev.of_node = pdev->dev.of_node;
217 rc = mdiobus_register(bus);
219 dev_err(&pdev->dev, "mdiomux registration failed\n");
223 platform_set_drvdata(pdev, md);
225 rc = mdio_mux_init(md->dev, md->dev->of_node, mdio_mux_iproc_switch_fn,
226 &md->mux_handle, md, md->mii_bus);
228 dev_info(md->dev, "mdiomux initialization failed\n");
232 mdio_mux_iproc_config(md);
234 dev_info(md->dev, "iProc mdiomux registered\n");
238 mdiobus_unregister(bus);
244 static int mdio_mux_iproc_remove(struct platform_device *pdev)
246 struct iproc_mdiomux_desc *md = platform_get_drvdata(pdev);
248 mdio_mux_uninit(md->mux_handle);
249 mdiobus_unregister(md->mii_bus);
250 mdiobus_free(md->mii_bus);
255 static const struct of_device_id mdio_mux_iproc_match[] = {
257 .compatible = "brcm,mdio-mux-iproc",
261 MODULE_DEVICE_TABLE(of, mdio_mux_iproc_match);
263 static struct platform_driver mdiomux_iproc_driver = {
265 .name = "mdio-mux-iproc",
266 .of_match_table = mdio_mux_iproc_match,
268 .probe = mdio_mux_iproc_probe,
269 .remove = mdio_mux_iproc_remove,
272 module_platform_driver(mdiomux_iproc_driver);
274 MODULE_DESCRIPTION("iProc MDIO Mux Bus Driver");
275 MODULE_AUTHOR("Pramod Kumar <pramod.kumar@broadcom.com>");
276 MODULE_LICENSE("GPL v2");