xref: /linux/drivers/net/phy/dp83td510.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Driver for the Texas Instruments DP83TD510 PHY
3  * Copyright (c) 2022 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
4  */
5 
6 #include <linux/bitfield.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/phy.h>
10 
11 #define DP83TD510E_PHY_ID			0x20000181
12 
13 /* MDIO_MMD_VEND2 registers */
14 #define DP83TD510E_PHY_STS			0x10
15 /* Bit 7 - mii_interrupt, active high. Clears on read.
16  * Note: Clearing does not necessarily deactivate IRQ pin if interrupts pending.
17  * This differs from the DP83TD510E datasheet (2020) which states this bit
18  * clears on write 0.
19  */
20 #define DP83TD510E_STS_MII_INT			BIT(7)
21 #define DP83TD510E_LINK_STATUS			BIT(0)
22 
23 #define DP83TD510E_GEN_CFG			0x11
24 #define DP83TD510E_GENCFG_INT_POLARITY		BIT(3)
25 #define DP83TD510E_GENCFG_INT_EN		BIT(1)
26 #define DP83TD510E_GENCFG_INT_OE		BIT(0)
27 
28 #define DP83TD510E_INTERRUPT_REG_1		0x12
29 #define DP83TD510E_INT1_LINK			BIT(13)
30 #define DP83TD510E_INT1_LINK_EN			BIT(5)
31 
32 #define DP83TD510E_AN_STAT_1			0x60c
33 #define DP83TD510E_MASTER_SLAVE_RESOL_FAIL	BIT(15)
34 
35 #define DP83TD510E_MSE_DETECT			0xa85
36 
37 #define DP83TD510_SQI_MAX	7
38 
39 /* Register values are converted to SNR(dB) as suggested by
40  * "Application Report - DP83TD510E Cable Diagnostics Toolkit":
41  * SNR(dB) = -10 * log10 (VAL/2^17) - 1.76 dB.
42  * SQI ranges are implemented according to "OPEN ALLIANCE - Advanced diagnostic
43  * features for 100BASE-T1 automotive Ethernet PHYs"
44  */
45 static const u16 dp83td510_mse_sqi_map[] = {
46 	0x0569, /* < 18dB */
47 	0x044c, /* 18dB =< SNR < 19dB */
48 	0x0369, /* 19dB =< SNR < 20dB */
49 	0x02b6, /* 20dB =< SNR < 21dB */
50 	0x0227, /* 21dB =< SNR < 22dB */
51 	0x01b6, /* 22dB =< SNR < 23dB */
52 	0x015b, /* 23dB =< SNR < 24dB */
53 	0x0000  /* 24dB =< SNR */
54 };
55 
56 static int dp83td510_config_intr(struct phy_device *phydev)
57 {
58 	int ret;
59 
60 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
61 		ret = phy_write_mmd(phydev, MDIO_MMD_VEND2,
62 				    DP83TD510E_INTERRUPT_REG_1,
63 				    DP83TD510E_INT1_LINK_EN);
64 		if (ret)
65 			return ret;
66 
67 		ret = phy_set_bits_mmd(phydev, MDIO_MMD_VEND2,
68 				       DP83TD510E_GEN_CFG,
69 				       DP83TD510E_GENCFG_INT_POLARITY |
70 				       DP83TD510E_GENCFG_INT_EN |
71 				       DP83TD510E_GENCFG_INT_OE);
72 	} else {
73 		ret = phy_write_mmd(phydev, MDIO_MMD_VEND2,
74 				    DP83TD510E_INTERRUPT_REG_1, 0x0);
75 		if (ret)
76 			return ret;
77 
78 		ret = phy_clear_bits_mmd(phydev, MDIO_MMD_VEND2,
79 					 DP83TD510E_GEN_CFG,
80 					 DP83TD510E_GENCFG_INT_EN);
81 		if (ret)
82 			return ret;
83 	}
84 
85 	return ret;
86 }
87 
88 static irqreturn_t dp83td510_handle_interrupt(struct phy_device *phydev)
89 {
90 	int  ret;
91 
92 	/* Read the current enabled interrupts */
93 	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_INTERRUPT_REG_1);
94 	if (ret < 0) {
95 		phy_error(phydev);
96 		return IRQ_NONE;
97 	} else if (!(ret & DP83TD510E_INT1_LINK_EN) ||
98 		   !(ret & DP83TD510E_INT1_LINK)) {
99 		return IRQ_NONE;
100 	}
101 
102 	phy_trigger_machine(phydev);
103 
104 	return IRQ_HANDLED;
105 }
106 
107 static int dp83td510_read_status(struct phy_device *phydev)
108 {
109 	u16 phy_sts;
110 	int ret;
111 
112 	phydev->speed = SPEED_UNKNOWN;
113 	phydev->duplex = DUPLEX_UNKNOWN;
114 	phydev->pause = 0;
115 	phydev->asym_pause = 0;
116 	linkmode_zero(phydev->lp_advertising);
117 
118 	phy_sts = phy_read(phydev, DP83TD510E_PHY_STS);
119 
120 	phydev->link = !!(phy_sts & DP83TD510E_LINK_STATUS);
121 	if (phydev->link) {
122 		/* This PHY supports only one link mode: 10BaseT1L_Full */
123 		phydev->duplex = DUPLEX_FULL;
124 		phydev->speed = SPEED_10;
125 
126 		if (phydev->autoneg == AUTONEG_ENABLE) {
127 			ret = genphy_c45_read_lpa(phydev);
128 			if (ret)
129 				return ret;
130 
131 			phy_resolve_aneg_linkmode(phydev);
132 		}
133 	}
134 
135 	if (phydev->autoneg == AUTONEG_ENABLE) {
136 		ret = genphy_c45_baset1_read_status(phydev);
137 		if (ret < 0)
138 			return ret;
139 
140 		ret = phy_read_mmd(phydev, MDIO_MMD_VEND2,
141 				   DP83TD510E_AN_STAT_1);
142 		if (ret < 0)
143 			return ret;
144 
145 		if (ret & DP83TD510E_MASTER_SLAVE_RESOL_FAIL)
146 			phydev->master_slave_state = MASTER_SLAVE_STATE_ERR;
147 	} else {
148 		return genphy_c45_pma_baset1_read_master_slave(phydev);
149 	}
150 
151 	return 0;
152 }
153 
154 static int dp83td510_config_aneg(struct phy_device *phydev)
155 {
156 	bool changed = false;
157 	int ret;
158 
159 	ret = genphy_c45_pma_baset1_setup_master_slave(phydev);
160 	if (ret < 0)
161 		return ret;
162 
163 	if (phydev->autoneg == AUTONEG_DISABLE)
164 		return genphy_c45_an_disable_aneg(phydev);
165 
166 	ret = genphy_c45_an_config_aneg(phydev);
167 	if (ret < 0)
168 		return ret;
169 	if (ret > 0)
170 		changed = true;
171 
172 	return genphy_c45_check_and_restart_aneg(phydev, changed);
173 }
174 
175 static int dp83td510_get_sqi(struct phy_device *phydev)
176 {
177 	int sqi, ret;
178 	u16 mse_val;
179 
180 	if (!phydev->link)
181 		return 0;
182 
183 	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_MSE_DETECT);
184 	if (ret < 0)
185 		return ret;
186 
187 	mse_val = 0xFFFF & ret;
188 	for (sqi = 0; sqi < ARRAY_SIZE(dp83td510_mse_sqi_map); sqi++) {
189 		if (mse_val >= dp83td510_mse_sqi_map[sqi])
190 			return sqi;
191 	}
192 
193 	return -EINVAL;
194 }
195 
196 static int dp83td510_get_sqi_max(struct phy_device *phydev)
197 {
198 	return DP83TD510_SQI_MAX;
199 }
200 
201 static int dp83td510_get_features(struct phy_device *phydev)
202 {
203 	/* This PHY can't respond on MDIO bus if no RMII clock is enabled.
204 	 * In case RMII mode is used (most meaningful mode for this PHY) and
205 	 * the PHY do not have own XTAL, and CLK providing MAC is not probed,
206 	 * we won't be able to read all needed ability registers.
207 	 * So provide it manually.
208 	 */
209 
210 	linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, phydev->supported);
211 	linkmode_set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, phydev->supported);
212 	linkmode_set_bit(ETHTOOL_LINK_MODE_Pause_BIT, phydev->supported);
213 	linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT1L_Full_BIT,
214 			 phydev->supported);
215 
216 	return 0;
217 }
218 
219 static struct phy_driver dp83td510_driver[] = {
220 {
221 	PHY_ID_MATCH_MODEL(DP83TD510E_PHY_ID),
222 	.name		= "TI DP83TD510E",
223 
224 	.config_aneg	= dp83td510_config_aneg,
225 	.read_status	= dp83td510_read_status,
226 	.get_features	= dp83td510_get_features,
227 	.config_intr	= dp83td510_config_intr,
228 	.handle_interrupt = dp83td510_handle_interrupt,
229 	.get_sqi	= dp83td510_get_sqi,
230 	.get_sqi_max	= dp83td510_get_sqi_max,
231 
232 	.suspend	= genphy_suspend,
233 	.resume		= genphy_resume,
234 } };
235 module_phy_driver(dp83td510_driver);
236 
237 static struct mdio_device_id __maybe_unused dp83td510_tbl[] = {
238 	{ PHY_ID_MATCH_MODEL(DP83TD510E_PHY_ID) },
239 	{ }
240 };
241 MODULE_DEVICE_TABLE(mdio, dp83td510_tbl);
242 
243 MODULE_DESCRIPTION("Texas Instruments DP83TD510E PHY driver");
244 MODULE_AUTHOR("Oleksij Rempel <kernel@pengutronix.de>");
245 MODULE_LICENSE("GPL v2");
246