1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright Sunplus Technology Co., Ltd.
3  *       All rights reserved.
4  */
5 
6 #include <linux/platform_device.h>
7 #include <linux/netdevice.h>
8 #include <linux/bitfield.h>
9 #include <linux/of_mdio.h>
10 
11 #include "spl2sw_register.h"
12 #include "spl2sw_define.h"
13 #include "spl2sw_mdio.h"
14 
15 #define SPL2SW_MDIO_READ_CMD           0x02
16 #define SPL2SW_MDIO_WRITE_CMD          0x01
17 
18 static int spl2sw_mdio_access(struct spl2sw_common *comm, u8 cmd, u8 addr, u8 regnum, u16 wdata)
19 {
20 	u32 reg, reg2;
21 	u32 val;
22 	int ret;
23 
24 	/* Note that addr (of phy) should match either ext_phy0_addr
25 	 * or ext_phy1_addr, or mdio commands won't be sent out.
26 	 */
27 	reg = readl(comm->l2sw_reg_base + L2SW_MAC_FORCE_MODE);
28 	reg &= ~MAC_EXT_PHY0_ADDR;
29 	reg |= FIELD_PREP(MAC_EXT_PHY0_ADDR, addr);
30 
31 	reg2 = FIELD_PREP(MAC_CPU_PHY_WT_DATA, wdata) | FIELD_PREP(MAC_CPU_PHY_CMD, cmd) |
32 	       FIELD_PREP(MAC_CPU_PHY_REG_ADDR, regnum) | FIELD_PREP(MAC_CPU_PHY_ADDR, addr);
33 
34 	/* Set ext_phy0_addr and then issue mdio command.
35 	 * No interrupt is allowed in between.
36 	 */
37 	spin_lock_irq(&comm->mdio_lock);
38 	writel(reg, comm->l2sw_reg_base + L2SW_MAC_FORCE_MODE);
39 	writel(reg2, comm->l2sw_reg_base + L2SW_PHY_CNTL_REG0);
40 	spin_unlock_irq(&comm->mdio_lock);
41 
42 	ret = read_poll_timeout(readl, val, val & cmd, 1, 1000, true,
43 				comm->l2sw_reg_base + L2SW_PHY_CNTL_REG1);
44 
45 	/* Set ext_phy0_addr back to 31 to prevent
46 	 * from sending mdio command to phy by
47 	 * hardware auto-mdio function.
48 	 */
49 	reg = readl(comm->l2sw_reg_base + L2SW_MAC_FORCE_MODE);
50 	reg &= ~MAC_EXT_PHY0_ADDR;
51 	reg |= FIELD_PREP(MAC_EXT_PHY0_ADDR, 31);
52 	writel(reg, comm->l2sw_reg_base + L2SW_MAC_FORCE_MODE);
53 
54 	if (ret == 0)
55 		return val >> 16;
56 	else
57 		return ret;
58 }
59 
60 static int spl2sw_mii_read(struct mii_bus *bus, int addr, int regnum)
61 {
62 	struct spl2sw_common *comm = bus->priv;
63 
64 	if (regnum & MII_ADDR_C45)
65 		return -EOPNOTSUPP;
66 
67 	return spl2sw_mdio_access(comm, SPL2SW_MDIO_READ_CMD, addr, regnum, 0);
68 }
69 
70 static int spl2sw_mii_write(struct mii_bus *bus, int addr, int regnum, u16 val)
71 {
72 	struct spl2sw_common *comm = bus->priv;
73 	int ret;
74 
75 	if (regnum & MII_ADDR_C45)
76 		return -EOPNOTSUPP;
77 
78 	ret = spl2sw_mdio_access(comm, SPL2SW_MDIO_WRITE_CMD, addr, regnum, val);
79 	if (ret < 0)
80 		return ret;
81 
82 	return 0;
83 }
84 
85 u32 spl2sw_mdio_init(struct spl2sw_common *comm)
86 {
87 	struct device_node *mdio_np;
88 	struct mii_bus *mii_bus;
89 	int ret;
90 
91 	/* Get mdio child node. */
92 	mdio_np = of_get_child_by_name(comm->pdev->dev.of_node, "mdio");
93 	if (!mdio_np) {
94 		dev_err(&comm->pdev->dev, "No mdio child node found!\n");
95 		return -ENODEV;
96 	}
97 
98 	/* Allocate and register mdio bus. */
99 	mii_bus = devm_mdiobus_alloc(&comm->pdev->dev);
100 	if (!mii_bus) {
101 		ret = -ENOMEM;
102 		goto out;
103 	}
104 
105 	mii_bus->name = "sunplus_mii_bus";
106 	mii_bus->parent = &comm->pdev->dev;
107 	mii_bus->priv = comm;
108 	mii_bus->read = spl2sw_mii_read;
109 	mii_bus->write = spl2sw_mii_write;
110 	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&comm->pdev->dev));
111 
112 	ret = of_mdiobus_register(mii_bus, mdio_np);
113 	if (ret) {
114 		dev_err(&comm->pdev->dev, "Failed to register mdiobus!\n");
115 		goto out;
116 	}
117 
118 	comm->mii_bus = mii_bus;
119 
120 out:
121 	of_node_put(mdio_np);
122 	return ret;
123 }
124 
125 void spl2sw_mdio_remove(struct spl2sw_common *comm)
126 {
127 	if (comm->mii_bus) {
128 		mdiobus_unregister(comm->mii_bus);
129 		comm->mii_bus = NULL;
130 	}
131 }
132