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  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_MASK	30
 34
 35#define BANK_ANALOG_DSP		0
 36#define BANK_WOL		1
 37#define BANK_BIST		3
 38
 39/* WOL Registers */
 40#define LPI_STATUS	0xc
 41#define  LPI_STATUS_RSV12	BIT(12)
 42
 43/* BIST Registers */
 44#define FR_PLL_CONTROL	0x1b
 45#define FR_PLL_DIV0	0x1c
 46#define FR_PLL_DIV1	0x1d
 47
 48static int meson_gxl_open_banks(struct phy_device *phydev)
 49{
 50	int ret;
 51
 52	/* Enable Analog and DSP register Bank access by
 53	 * toggling TSTCNTL_TEST_MODE bit in the TSTCNTL register
 54	 */
 55	ret = phy_write(phydev, TSTCNTL, 0);
 56	if (ret)
 57		return ret;
 58	ret = phy_write(phydev, TSTCNTL, TSTCNTL_TEST_MODE);
 59	if (ret)
 60		return ret;
 61	ret = phy_write(phydev, TSTCNTL, 0);
 62	if (ret)
 63		return ret;
 64	return phy_write(phydev, TSTCNTL, TSTCNTL_TEST_MODE);
 65}
 66
 67static void meson_gxl_close_banks(struct phy_device *phydev)
 68{
 69	phy_write(phydev, TSTCNTL, 0);
 70}
 71
 72static int meson_gxl_read_reg(struct phy_device *phydev,
 73			      unsigned int bank, unsigned int reg)
 74{
 75	int ret;
 76
 77	ret = meson_gxl_open_banks(phydev);
 78	if (ret)
 79		goto out;
 80
 81	ret = phy_write(phydev, TSTCNTL, TSTCNTL_READ |
 82			FIELD_PREP(TSTCNTL_REG_BANK_SEL, bank) |
 83			TSTCNTL_TEST_MODE |
 84			FIELD_PREP(TSTCNTL_READ_ADDRESS, reg));
 85	if (ret)
 86		goto out;
 87
 88	ret = phy_read(phydev, TSTREAD1);
 89out:
 90	/* Close the bank access on our way out */
 91	meson_gxl_close_banks(phydev);
 92	return ret;
 93}
 94
 95static int meson_gxl_write_reg(struct phy_device *phydev,
 96			       unsigned int bank, unsigned int reg,
 97			       uint16_t value)
 98{
 99	int ret;
100
101	ret = meson_gxl_open_banks(phydev);
102	if (ret)
103		goto out;
104
105	ret = phy_write(phydev, TSTWRITE, value);
106	if (ret)
107		goto out;
108
109	ret = phy_write(phydev, TSTCNTL, TSTCNTL_WRITE |
110			FIELD_PREP(TSTCNTL_REG_BANK_SEL, bank) |
111			TSTCNTL_TEST_MODE |
112			FIELD_PREP(TSTCNTL_WRITE_ADDRESS, reg));
113
114out:
115	/* Close the bank access on our way out */
116	meson_gxl_close_banks(phydev);
117	return ret;
118}
119
120static int meson_gxl_config_init(struct phy_device *phydev)
121{
122	int ret;
123
124	/* Enable fractional PLL */
125	ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_CONTROL, 0x5);
126	if (ret)
127		return ret;
128
129	/* Program fraction FR_PLL_DIV1 */
130	ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_DIV1, 0x029a);
131	if (ret)
132		return ret;
133
134	/* Program fraction FR_PLL_DIV1 */
135	ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_DIV0, 0xaaaa);
136	if (ret)
137		return ret;
138
139	return 0;
140}
141
142/* This function is provided to cope with the possible failures of this phy
143 * during aneg process. When aneg fails, the PHY reports that aneg is done
144 * but the value found in MII_LPA is wrong:
145 *  - Early failures: MII_LPA is just 0x0001. if MII_EXPANSION reports that
146 *    the link partner (LP) supports aneg but the LP never acked our base
147 *    code word, it is likely that we never sent it to begin with.
148 *  - Late failures: MII_LPA is filled with a value which seems to make sense
149 *    but it actually is not what the LP is advertising. It seems that we
150 *    can detect this using a magic bit in the WOL bank (reg 12 - bit 12).
151 *    If this particular bit is not set when aneg is reported being done,
152 *    it means MII_LPA is likely to be wrong.
153 *
154 * In both case, forcing a restart of the aneg process solve the problem.
155 * When this failure happens, the first retry is usually successful but,
156 * in some cases, it may take up to 6 retries to get a decent result
157 */
158static int meson_gxl_read_status(struct phy_device *phydev)
159{
160	int ret, wol, lpa, exp;
161
162	if (phydev->autoneg == AUTONEG_ENABLE) {
163		ret = genphy_aneg_done(phydev);
164		if (ret < 0)
165			return ret;
166		else if (!ret)
167			goto read_status_continue;
168
169		/* Aneg is done, let's check everything is fine */
170		wol = meson_gxl_read_reg(phydev, BANK_WOL, LPI_STATUS);
171		if (wol < 0)
172			return wol;
173
174		lpa = phy_read(phydev, MII_LPA);
175		if (lpa < 0)
176			return lpa;
177
178		exp = phy_read(phydev, MII_EXPANSION);
179		if (exp < 0)
180			return exp;
181
182		if (!(wol & LPI_STATUS_RSV12) ||
183		    ((exp & EXPANSION_NWAY) && !(lpa & LPA_LPACK))) {
184			/* Looks like aneg failed after all */
185			phydev_dbg(phydev, "LPA corruption - aneg restart\n");
186			return genphy_restart_aneg(phydev);
187		}
188	}
189
190read_status_continue:
191	return genphy_read_status(phydev);
192}
193
194static int meson_gxl_ack_interrupt(struct phy_device *phydev)
195{
196	int ret = phy_read(phydev, INTSRC_FLAG);
197
198	return ret < 0 ? ret : 0;
199}
200
201static int meson_gxl_config_intr(struct phy_device *phydev)
202{
203	u16 val;
204	int ret;
205
206	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
207		/* Ack any pending IRQ */
208		ret = meson_gxl_ack_interrupt(phydev);
209		if (ret)
210			return ret;
211
212		val = INTSRC_ANEG_PR
213			| INTSRC_PARALLEL_FAULT
214			| INTSRC_ANEG_LP_ACK
215			| INTSRC_LINK_DOWN
216			| INTSRC_REMOTE_FAULT
217			| INTSRC_ANEG_COMPLETE;
218		ret = phy_write(phydev, INTSRC_MASK, val);
219	} else {
220		val = 0;
221		ret = phy_write(phydev, INTSRC_MASK, val);
222
223		/* Ack any pending IRQ */
224		ret = meson_gxl_ack_interrupt(phydev);
225	}
226
227	return ret;
228}
229
230static irqreturn_t meson_gxl_handle_interrupt(struct phy_device *phydev)
231{
232	int irq_status;
233
234	irq_status = phy_read(phydev, INTSRC_FLAG);
235	if (irq_status < 0) {
236		phy_error(phydev);
237		return IRQ_NONE;
238	}
239
240	if (irq_status == 0)
241		return IRQ_NONE;
242
243	phy_trigger_machine(phydev);
244
245	return IRQ_HANDLED;
246}
247
248static struct phy_driver meson_gxl_phy[] = {
249	{
250		PHY_ID_MATCH_EXACT(0x01814400),
251		.name		= "Meson GXL Internal PHY",
252		/* PHY_BASIC_FEATURES */
253		.flags		= PHY_IS_INTERNAL,
254		.soft_reset     = genphy_soft_reset,
255		.config_init	= meson_gxl_config_init,
256		.read_status	= meson_gxl_read_status,
257		.config_intr	= meson_gxl_config_intr,
258		.handle_interrupt = meson_gxl_handle_interrupt,
259		.suspend        = genphy_suspend,
260		.resume         = genphy_resume,
261	}, {
262		PHY_ID_MATCH_EXACT(0x01803301),
263		.name		= "Meson G12A Internal PHY",
264		/* PHY_BASIC_FEATURES */
265		.flags		= PHY_IS_INTERNAL,
266		.soft_reset     = genphy_soft_reset,
267		.config_intr	= meson_gxl_config_intr,
268		.handle_interrupt = meson_gxl_handle_interrupt,
269		.suspend        = genphy_suspend,
270		.resume         = genphy_resume,
271	},
272};
273
274static struct mdio_device_id __maybe_unused meson_gxl_tbl[] = {
275	{ PHY_ID_MATCH_VENDOR(0x01814400) },
276	{ PHY_ID_MATCH_VENDOR(0x01803301) },
277	{ }
278};
279
280module_phy_driver(meson_gxl_phy);
281
282MODULE_DEVICE_TABLE(mdio, meson_gxl_tbl);
283
284MODULE_DESCRIPTION("Amlogic Meson GXL Internal PHY driver");
285MODULE_AUTHOR("Baoqi wang");
286MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
287MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
288MODULE_LICENSE("GPL");