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Timur Tabib9b17de2016-08-31 18:22:08 -05001/* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
2 *
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 and
5 * only version 2 as published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 */
12
13/* Qualcomm Technologies, Inc. EMAC PHY Controller driver.
14 */
15
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/of_net.h>
19#include <linux/of_mdio.h>
20#include <linux/phy.h>
21#include <linux/iopoll.h>
Timur Tabi5f3d3802016-09-28 11:58:44 -050022#include <linux/acpi.h>
Timur Tabib9b17de2016-08-31 18:22:08 -050023#include "emac.h"
24#include "emac-mac.h"
25#include "emac-phy.h"
26#include "emac-sgmii.h"
27
28/* EMAC base register offsets */
29#define EMAC_MDIO_CTRL 0x001414
30#define EMAC_PHY_STS 0x001418
31#define EMAC_MDIO_EX_CTRL 0x001440
32
33/* EMAC_MDIO_CTRL */
34#define MDIO_MODE BIT(30)
35#define MDIO_PR BIT(29)
36#define MDIO_AP_EN BIT(28)
37#define MDIO_BUSY BIT(27)
38#define MDIO_CLK_SEL_BMSK 0x7000000
39#define MDIO_CLK_SEL_SHFT 24
40#define MDIO_START BIT(23)
41#define SUP_PREAMBLE BIT(22)
42#define MDIO_RD_NWR BIT(21)
43#define MDIO_REG_ADDR_BMSK 0x1f0000
44#define MDIO_REG_ADDR_SHFT 16
45#define MDIO_DATA_BMSK 0xffff
46#define MDIO_DATA_SHFT 0
47
48/* EMAC_PHY_STS */
49#define PHY_ADDR_BMSK 0x1f0000
50#define PHY_ADDR_SHFT 16
51
52#define MDIO_CLK_25_4 0
53#define MDIO_CLK_25_28 7
54
55#define MDIO_WAIT_TIMES 1000
56
57#define EMAC_LINK_SPEED_DEFAULT (\
58 EMAC_LINK_SPEED_10_HALF |\
59 EMAC_LINK_SPEED_10_FULL |\
60 EMAC_LINK_SPEED_100_HALF |\
61 EMAC_LINK_SPEED_100_FULL |\
62 EMAC_LINK_SPEED_1GB_FULL)
63
64/**
65 * emac_phy_mdio_autopoll_disable() - disable mdio autopoll
66 * @adpt: the emac adapter
67 *
68 * The autopoll feature takes over the MDIO bus. In order for
69 * the PHY driver to be able to talk to the PHY over the MDIO
70 * bus, we need to temporarily disable the autopoll feature.
71 */
72static int emac_phy_mdio_autopoll_disable(struct emac_adapter *adpt)
73{
74 u32 val;
75
76 /* disable autopoll */
77 emac_reg_update32(adpt->base + EMAC_MDIO_CTRL, MDIO_AP_EN, 0);
78
79 /* wait for any mdio polling to complete */
80 if (!readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, val,
81 !(val & MDIO_BUSY), 100, MDIO_WAIT_TIMES * 100))
82 return 0;
83
84 /* failed to disable; ensure it is enabled before returning */
85 emac_reg_update32(adpt->base + EMAC_MDIO_CTRL, 0, MDIO_AP_EN);
86
87 return -EBUSY;
88}
89
90/**
91 * emac_phy_mdio_autopoll_disable() - disable mdio autopoll
92 * @adpt: the emac adapter
93 *
94 * The EMAC has the ability to poll the external PHY on the MDIO
95 * bus for link state changes. This eliminates the need for the
96 * driver to poll the phy. If if the link state does change,
97 * the EMAC issues an interrupt on behalf of the PHY.
98 */
99static void emac_phy_mdio_autopoll_enable(struct emac_adapter *adpt)
100{
101 emac_reg_update32(adpt->base + EMAC_MDIO_CTRL, 0, MDIO_AP_EN);
102}
103
104static int emac_mdio_read(struct mii_bus *bus, int addr, int regnum)
105{
106 struct emac_adapter *adpt = bus->priv;
107 u32 reg;
108 int ret;
109
110 ret = emac_phy_mdio_autopoll_disable(adpt);
111 if (ret)
112 return ret;
113
114 emac_reg_update32(adpt->base + EMAC_PHY_STS, PHY_ADDR_BMSK,
115 (addr << PHY_ADDR_SHFT));
116
117 reg = SUP_PREAMBLE |
118 ((MDIO_CLK_25_4 << MDIO_CLK_SEL_SHFT) & MDIO_CLK_SEL_BMSK) |
119 ((regnum << MDIO_REG_ADDR_SHFT) & MDIO_REG_ADDR_BMSK) |
120 MDIO_START | MDIO_RD_NWR;
121
122 writel(reg, adpt->base + EMAC_MDIO_CTRL);
123
124 if (readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, reg,
125 !(reg & (MDIO_START | MDIO_BUSY)),
126 100, MDIO_WAIT_TIMES * 100))
127 ret = -EIO;
128 else
129 ret = (reg >> MDIO_DATA_SHFT) & MDIO_DATA_BMSK;
130
131 emac_phy_mdio_autopoll_enable(adpt);
132
133 return ret;
134}
135
136static int emac_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val)
137{
138 struct emac_adapter *adpt = bus->priv;
139 u32 reg;
140 int ret;
141
142 ret = emac_phy_mdio_autopoll_disable(adpt);
143 if (ret)
144 return ret;
145
146 emac_reg_update32(adpt->base + EMAC_PHY_STS, PHY_ADDR_BMSK,
147 (addr << PHY_ADDR_SHFT));
148
149 reg = SUP_PREAMBLE |
150 ((MDIO_CLK_25_4 << MDIO_CLK_SEL_SHFT) & MDIO_CLK_SEL_BMSK) |
151 ((regnum << MDIO_REG_ADDR_SHFT) & MDIO_REG_ADDR_BMSK) |
152 ((val << MDIO_DATA_SHFT) & MDIO_DATA_BMSK) |
153 MDIO_START;
154
155 writel(reg, adpt->base + EMAC_MDIO_CTRL);
156
157 if (readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, reg,
158 !(reg & (MDIO_START | MDIO_BUSY)), 100,
159 MDIO_WAIT_TIMES * 100))
160 ret = -EIO;
161
162 emac_phy_mdio_autopoll_enable(adpt);
163
164 return ret;
165}
166
167/* Configure the MDIO bus and connect the external PHY */
168int emac_phy_config(struct platform_device *pdev, struct emac_adapter *adpt)
169{
170 struct device_node *np = pdev->dev.of_node;
Timur Tabib9b17de2016-08-31 18:22:08 -0500171 struct mii_bus *mii_bus;
172 int ret;
173
174 /* Create the mii_bus object for talking to the MDIO bus */
175 adpt->mii_bus = mii_bus = devm_mdiobus_alloc(&pdev->dev);
176 if (!mii_bus)
177 return -ENOMEM;
178
179 mii_bus->name = "emac-mdio";
180 snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);
181 mii_bus->read = emac_mdio_read;
182 mii_bus->write = emac_mdio_write;
183 mii_bus->parent = &pdev->dev;
184 mii_bus->priv = adpt;
185
Timur Tabi5f3d3802016-09-28 11:58:44 -0500186 if (has_acpi_companion(&pdev->dev)) {
187 u32 phy_addr;
188
189 ret = mdiobus_register(mii_bus);
190 if (ret) {
191 dev_err(&pdev->dev, "could not register mdio bus\n");
192 return ret;
193 }
194 ret = device_property_read_u32(&pdev->dev, "phy-channel",
195 &phy_addr);
196 if (ret)
197 /* If we can't read a valid phy address, then assume
198 * that there is only one phy on this mdio bus.
199 */
200 adpt->phydev = phy_find_first(mii_bus);
201 else
202 adpt->phydev = mdiobus_get_phy(mii_bus, phy_addr);
203
Timur Tabi994c5482017-01-11 16:45:51 -0600204 /* of_phy_find_device() claims a reference to the phydev,
205 * so we do that here manually as well. When the driver
206 * later unloads, it can unilaterally drop the reference
207 * without worrying about ACPI vs DT.
208 */
209 if (adpt->phydev)
210 get_device(&adpt->phydev->mdio.dev);
Timur Tabi5f3d3802016-09-28 11:58:44 -0500211 } else {
212 struct device_node *phy_np;
213
214 ret = of_mdiobus_register(mii_bus, np);
215 if (ret) {
216 dev_err(&pdev->dev, "could not register mdio bus\n");
217 return ret;
218 }
219
220 phy_np = of_parse_phandle(np, "phy-handle", 0);
221 adpt->phydev = of_phy_find_device(phy_np);
Johan Hovold6ffe1c42016-11-24 19:21:31 +0100222 of_node_put(phy_np);
Timur Tabib9b17de2016-08-31 18:22:08 -0500223 }
224
Timur Tabib9b17de2016-08-31 18:22:08 -0500225 if (!adpt->phydev) {
226 dev_err(&pdev->dev, "could not find external phy\n");
227 mdiobus_unregister(mii_bus);
228 return -ENODEV;
229 }
230
231 if (adpt->phydev->drv)
232 phy_attached_print(adpt->phydev, NULL);
233
234 return 0;
235}