1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * drivers/net/phy/national.c
4 *
5 * Driver for National Semiconductor PHYs
6 *
7 * Author: Stuart Menefy <stuart.menefy@st.com>
8 * Maintainer: Giuseppe Cavallaro <peppe.cavallaro@st.com>
9 *
10 * Copyright (c) 2008 STMicroelectronics Limited
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/mii.h>
18#include <linux/ethtool.h>
19#include <linux/phy.h>
20#include <linux/netdevice.h>
21
22/* DP83865 phy identifier values */
23#define DP83865_PHY_ID	0x20005c7a
24
25#define DP83865_INT_STATUS	0x14
26#define DP83865_INT_MASK	0x15
27#define DP83865_INT_CLEAR	0x17
28
29#define DP83865_INT_REMOTE_FAULT 0x0008
30#define DP83865_INT_ANE_COMPLETED 0x0010
31#define DP83865_INT_LINK_CHANGE	0xe000
32#define DP83865_INT_MASK_DEFAULT (DP83865_INT_REMOTE_FAULT | \
33				DP83865_INT_ANE_COMPLETED | \
34				DP83865_INT_LINK_CHANGE)
35
36/* Advanced proprietary configuration */
37#define NS_EXP_MEM_CTL	0x16
38#define NS_EXP_MEM_DATA	0x1d
39#define NS_EXP_MEM_ADD	0x1e
40
41#define LED_CTRL_REG 0x13
42#define AN_FALLBACK_AN 0x0001
43#define AN_FALLBACK_CRC 0x0002
44#define AN_FALLBACK_IE 0x0004
45#define ALL_FALLBACK_ON (AN_FALLBACK_AN |  AN_FALLBACK_CRC | AN_FALLBACK_IE)
46
47enum hdx_loopback {
48	hdx_loopback_on = 0,
49	hdx_loopback_off = 1,
50};
51
52static u8 ns_exp_read(struct phy_device *phydev, u16 reg)
53{
54	phy_write(phydev, NS_EXP_MEM_ADD, reg);
55	return phy_read(phydev, NS_EXP_MEM_DATA);
56}
57
58static void ns_exp_write(struct phy_device *phydev, u16 reg, u8 data)
59{
60	phy_write(phydev, NS_EXP_MEM_ADD, reg);
61	phy_write(phydev, NS_EXP_MEM_DATA, data);
62}
63
64static int ns_ack_interrupt(struct phy_device *phydev)
65{
66	int ret = phy_read(phydev, DP83865_INT_STATUS);
67	if (ret < 0)
68		return ret;
69
70	/* Clear the interrupt status bit by writing a “1”
71	 * to the corresponding bit in INT_CLEAR (2:0 are reserved)
72	 */
73	ret = phy_write(phydev, DP83865_INT_CLEAR, ret & ~0x7);
74
75	return ret;
76}
77
78static irqreturn_t ns_handle_interrupt(struct phy_device *phydev)
79{
80	int irq_status;
81
82	irq_status = phy_read(phydev, DP83865_INT_STATUS);
83	if (irq_status < 0) {
84		phy_error(phydev);
85		return IRQ_NONE;
86	}
87
88	if (!(irq_status & DP83865_INT_MASK_DEFAULT))
89		return IRQ_NONE;
90
91	/* clear the interrupt */
92	phy_write(phydev, DP83865_INT_CLEAR, irq_status & ~0x7);
93
94	phy_trigger_machine(phydev);
95
96	return IRQ_HANDLED;
97}
98
99static int ns_config_intr(struct phy_device *phydev)
100{
101	int err;
102
103	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
104		err = ns_ack_interrupt(phydev);
105		if (err)
106			return err;
107
108		err = phy_write(phydev, DP83865_INT_MASK,
109				DP83865_INT_MASK_DEFAULT);
110	} else {
111		err = phy_write(phydev, DP83865_INT_MASK, 0);
112		if (err)
113			return err;
114
115		err = ns_ack_interrupt(phydev);
116	}
117
118	return err;
119}
120
121static void ns_giga_speed_fallback(struct phy_device *phydev, int mode)
122{
123	int bmcr = phy_read(phydev, MII_BMCR);
124
125	phy_write(phydev, MII_BMCR, (bmcr | BMCR_PDOWN));
126
127	/* Enable 8 bit expended memory read/write (no auto increment) */
128	phy_write(phydev, NS_EXP_MEM_CTL, 0);
129	phy_write(phydev, NS_EXP_MEM_ADD, 0x1C0);
130	phy_write(phydev, NS_EXP_MEM_DATA, 0x0008);
131	phy_write(phydev, MII_BMCR, (bmcr & ~BMCR_PDOWN));
132	phy_write(phydev, LED_CTRL_REG, mode);
133}
134
135static void ns_10_base_t_hdx_loopack(struct phy_device *phydev, int disable)
136{
137	u16 lb_dis = BIT(1);
138
139	if (disable)
140		ns_exp_write(phydev, 0x1c0,
141			     ns_exp_read(phydev, 0x1c0) | lb_dis);
142	else
143		ns_exp_write(phydev, 0x1c0,
144			     ns_exp_read(phydev, 0x1c0) & ~lb_dis);
145
146	pr_debug("10BASE-T HDX loopback %s\n",
147		 (ns_exp_read(phydev, 0x1c0) & lb_dis) ? "off" : "on");
148}
149
150static int ns_config_init(struct phy_device *phydev)
151{
152	ns_giga_speed_fallback(phydev, ALL_FALLBACK_ON);
153	/* In the latest MAC or switches design, the 10 Mbps loopback
154	 * is desired to be turned off.
155	 */
156	ns_10_base_t_hdx_loopack(phydev, hdx_loopback_off);
157	return ns_ack_interrupt(phydev);
158}
159
160static struct phy_driver dp83865_driver[] = { {
161	.phy_id = DP83865_PHY_ID,
162	.phy_id_mask = 0xfffffff0,
163	.name = "NatSemi DP83865",
164	/* PHY_GBIT_FEATURES */
165	.config_init = ns_config_init,
166	.config_intr = ns_config_intr,
167	.handle_interrupt = ns_handle_interrupt,
168} };
169
170module_phy_driver(dp83865_driver);
171
172MODULE_DESCRIPTION("NatSemi PHY driver");
173MODULE_AUTHOR("Stuart Menefy");
174MODULE_LICENSE("GPL");
175
176static struct mdio_device_id __maybe_unused ns_tbl[] = {
177	{ DP83865_PHY_ID, 0xfffffff0 },
178	{ }
179};
180
181MODULE_DEVICE_TABLE(mdio, ns_tbl);
182