1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Amlogic Meson GXL Internal PHY Driver
4 *
5 * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
6 * Copyright (C) 2016 BayLibre, SAS. All rights reserved.
7 * Author: Neil Armstrong <narmstrong@baylibre.com>
8 */
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/mii.h>
12 #include <linux/ethtool.h>
13 #include <linux/phy.h>
14 #include <linux/netdevice.h>
15 #include <linux/bitfield.h>
16
17 #define TSTCNTL 20
18 #define TSTCNTL_READ BIT(15)
19 #define TSTCNTL_WRITE BIT(14)
20 #define TSTCNTL_REG_BANK_SEL GENMASK(12, 11)
21 #define TSTCNTL_TEST_MODE BIT(10)
22 #define TSTCNTL_READ_ADDRESS GENMASK(9, 5)
23 #define TSTCNTL_WRITE_ADDRESS GENMASK(4, 0)
24 #define TSTREAD1 21
25 #define TSTWRITE 23
26 #define INTSRC_FLAG 29
27 #define INTSRC_ANEG_PR BIT(1)
28 #define INTSRC_PARALLEL_FAULT BIT(2)
29 #define INTSRC_ANEG_LP_ACK BIT(3)
30 #define INTSRC_LINK_DOWN BIT(4)
31 #define INTSRC_REMOTE_FAULT BIT(5)
32 #define INTSRC_ANEG_COMPLETE BIT(6)
33 #define INTSRC_ENERGY_DETECT BIT(7)
34 #define INTSRC_MASK 30
35
36 #define INT_SOURCES (INTSRC_LINK_DOWN | INTSRC_ANEG_COMPLETE | \
37 INTSRC_ENERGY_DETECT)
38
39 #define BANK_ANALOG_DSP 0
40 #define BANK_WOL 1
41 #define BANK_BIST 3
42
43 /* WOL Registers */
44 #define LPI_STATUS 0xc
45 #define LPI_STATUS_RSV12 BIT(12)
46
47 /* BIST Registers */
48 #define FR_PLL_CONTROL 0x1b
49 #define FR_PLL_DIV0 0x1c
50 #define FR_PLL_DIV1 0x1d
51
meson_gxl_open_banks(struct phy_device * phydev)52 static int meson_gxl_open_banks(struct phy_device *phydev)
53 {
54 int ret;
55
56 /* Enable Analog and DSP register Bank access by
57 * toggling TSTCNTL_TEST_MODE bit in the TSTCNTL register
58 */
59 ret = phy_write(phydev, TSTCNTL, 0);
60 if (ret)
61 return ret;
62 ret = phy_write(phydev, TSTCNTL, TSTCNTL_TEST_MODE);
63 if (ret)
64 return ret;
65 ret = phy_write(phydev, TSTCNTL, 0);
66 if (ret)
67 return ret;
68 return phy_write(phydev, TSTCNTL, TSTCNTL_TEST_MODE);
69 }
70
meson_gxl_close_banks(struct phy_device * phydev)71 static void meson_gxl_close_banks(struct phy_device *phydev)
72 {
73 phy_write(phydev, TSTCNTL, 0);
74 }
75
meson_gxl_read_reg(struct phy_device * phydev,unsigned int bank,unsigned int reg)76 static int meson_gxl_read_reg(struct phy_device *phydev,
77 unsigned int bank, unsigned int reg)
78 {
79 int ret;
80
81 ret = meson_gxl_open_banks(phydev);
82 if (ret)
83 goto out;
84
85 ret = phy_write(phydev, TSTCNTL, TSTCNTL_READ |
86 FIELD_PREP(TSTCNTL_REG_BANK_SEL, bank) |
87 TSTCNTL_TEST_MODE |
88 FIELD_PREP(TSTCNTL_READ_ADDRESS, reg));
89 if (ret)
90 goto out;
91
92 ret = phy_read(phydev, TSTREAD1);
93 out:
94 /* Close the bank access on our way out */
95 meson_gxl_close_banks(phydev);
96 return ret;
97 }
98
meson_gxl_write_reg(struct phy_device * phydev,unsigned int bank,unsigned int reg,uint16_t value)99 static int meson_gxl_write_reg(struct phy_device *phydev,
100 unsigned int bank, unsigned int reg,
101 uint16_t value)
102 {
103 int ret;
104
105 ret = meson_gxl_open_banks(phydev);
106 if (ret)
107 goto out;
108
109 ret = phy_write(phydev, TSTWRITE, value);
110 if (ret)
111 goto out;
112
113 ret = phy_write(phydev, TSTCNTL, TSTCNTL_WRITE |
114 FIELD_PREP(TSTCNTL_REG_BANK_SEL, bank) |
115 TSTCNTL_TEST_MODE |
116 FIELD_PREP(TSTCNTL_WRITE_ADDRESS, reg));
117
118 out:
119 /* Close the bank access on our way out */
120 meson_gxl_close_banks(phydev);
121 return ret;
122 }
123
meson_gxl_config_init(struct phy_device * phydev)124 static int meson_gxl_config_init(struct phy_device *phydev)
125 {
126 int ret;
127
128 /* Enable fractional PLL */
129 ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_CONTROL, 0x5);
130 if (ret)
131 return ret;
132
133 /* Program fraction FR_PLL_DIV1 */
134 ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_DIV1, 0x029a);
135 if (ret)
136 return ret;
137
138 /* Program fraction FR_PLL_DIV1 */
139 ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_DIV0, 0xaaaa);
140 if (ret)
141 return ret;
142
143 return 0;
144 }
145
146 /* This function is provided to cope with the possible failures of this phy
147 * during aneg process. When aneg fails, the PHY reports that aneg is done
148 * but the value found in MII_LPA is wrong:
149 * - Early failures: MII_LPA is just 0x0001. if MII_EXPANSION reports that
150 * the link partner (LP) supports aneg but the LP never acked our base
151 * code word, it is likely that we never sent it to begin with.
152 * - Late failures: MII_LPA is filled with a value which seems to make sense
153 * but it actually is not what the LP is advertising. It seems that we
154 * can detect this using a magic bit in the WOL bank (reg 12 - bit 12).
155 * If this particular bit is not set when aneg is reported being done,
156 * it means MII_LPA is likely to be wrong.
157 *
158 * In both case, forcing a restart of the aneg process solve the problem.
159 * When this failure happens, the first retry is usually successful but,
160 * in some cases, it may take up to 6 retries to get a decent result
161 */
meson_gxl_read_status(struct phy_device * phydev)162 static int meson_gxl_read_status(struct phy_device *phydev)
163 {
164 int ret, wol, lpa, exp;
165
166 if (phydev->autoneg == AUTONEG_ENABLE) {
167 ret = genphy_aneg_done(phydev);
168 if (ret < 0)
169 return ret;
170 else if (!ret)
171 goto read_status_continue;
172
173 /* Aneg is done, let's check everything is fine */
174 wol = meson_gxl_read_reg(phydev, BANK_WOL, LPI_STATUS);
175 if (wol < 0)
176 return wol;
177
178 lpa = phy_read(phydev, MII_LPA);
179 if (lpa < 0)
180 return lpa;
181
182 exp = phy_read(phydev, MII_EXPANSION);
183 if (exp < 0)
184 return exp;
185
186 if (!(wol & LPI_STATUS_RSV12) ||
187 ((exp & EXPANSION_NWAY) && !(lpa & LPA_LPACK))) {
188 /* Looks like aneg failed after all */
189 phydev_dbg(phydev, "LPA corruption - aneg restart\n");
190 return genphy_restart_aneg(phydev);
191 }
192 }
193
194 read_status_continue:
195 return genphy_read_status(phydev);
196 }
197
meson_gxl_ack_interrupt(struct phy_device * phydev)198 static int meson_gxl_ack_interrupt(struct phy_device *phydev)
199 {
200 int ret = phy_read(phydev, INTSRC_FLAG);
201
202 return ret < 0 ? ret : 0;
203 }
204
meson_gxl_config_intr(struct phy_device * phydev)205 static int meson_gxl_config_intr(struct phy_device *phydev)
206 {
207 int ret;
208
209 if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
210 /* Ack any pending IRQ */
211 ret = meson_gxl_ack_interrupt(phydev);
212 if (ret)
213 return ret;
214
215 ret = phy_write(phydev, INTSRC_MASK, INT_SOURCES);
216 } else {
217 ret = phy_write(phydev, INTSRC_MASK, 0);
218
219 /* Ack any pending IRQ */
220 ret = meson_gxl_ack_interrupt(phydev);
221 }
222
223 return ret;
224 }
225
meson_gxl_handle_interrupt(struct phy_device * phydev)226 static irqreturn_t meson_gxl_handle_interrupt(struct phy_device *phydev)
227 {
228 int irq_status;
229
230 irq_status = phy_read(phydev, INTSRC_FLAG);
231 if (irq_status < 0) {
232 phy_error(phydev);
233 return IRQ_NONE;
234 }
235
236 irq_status &= INT_SOURCES;
237
238 if (irq_status == 0)
239 return IRQ_NONE;
240
241 /* Aneg-complete interrupt is used for link-up detection */
242 if (phydev->autoneg == AUTONEG_ENABLE &&
243 irq_status == INTSRC_ENERGY_DETECT)
244 return IRQ_HANDLED;
245
246 phy_trigger_machine(phydev);
247
248 return IRQ_HANDLED;
249 }
250
251 static struct phy_driver meson_gxl_phy[] = {
252 {
253 PHY_ID_MATCH_EXACT(0x01814400),
254 .name = "Meson GXL Internal PHY",
255 /* PHY_BASIC_FEATURES */
256 .flags = PHY_IS_INTERNAL,
257 .soft_reset = genphy_soft_reset,
258 .config_init = meson_gxl_config_init,
259 .read_status = meson_gxl_read_status,
260 .config_intr = meson_gxl_config_intr,
261 .handle_interrupt = meson_gxl_handle_interrupt,
262 .suspend = genphy_suspend,
263 .resume = genphy_resume,
264 .read_mmd = genphy_read_mmd_unsupported,
265 .write_mmd = genphy_write_mmd_unsupported,
266 }, {
267 PHY_ID_MATCH_EXACT(0x01803301),
268 .name = "Meson G12A Internal PHY",
269 /* PHY_BASIC_FEATURES */
270 .flags = PHY_IS_INTERNAL,
271 .soft_reset = genphy_soft_reset,
272 .config_intr = meson_gxl_config_intr,
273 .handle_interrupt = meson_gxl_handle_interrupt,
274 .suspend = genphy_suspend,
275 .resume = genphy_resume,
276 .read_mmd = genphy_read_mmd_unsupported,
277 .write_mmd = genphy_write_mmd_unsupported,
278 },
279 };
280
281 static struct mdio_device_id __maybe_unused meson_gxl_tbl[] = {
282 { PHY_ID_MATCH_VENDOR(0x01814400) },
283 { PHY_ID_MATCH_VENDOR(0x01803301) },
284 { }
285 };
286
287 module_phy_driver(meson_gxl_phy);
288
289 MODULE_DEVICE_TABLE(mdio, meson_gxl_tbl);
290
291 MODULE_DESCRIPTION("Amlogic Meson GXL Internal PHY driver");
292 MODULE_AUTHOR("Baoqi wang");
293 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
294 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
295 MODULE_LICENSE("GPL");
296