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Tom Rini10e47792018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +05302/*
3 * pic32_mdio.c: PIC32 MDIO/MII driver, part of pic32_eth.c.
4 *
5 * Copyright 2015 Microchip Inc.
6 * Purna Chandra Mandal <purna.mandal@microchip.com>
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +05307 */
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +05308#include <phy.h>
9#include <miiphy.h>
10#include <errno.h>
11#include <wait_bit.h>
12#include <asm/io.h>
Simon Glassdbd79542020-05-10 11:40:11 -060013#include <linux/delay.h>
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +053014#include "pic32_eth.h"
15
16static int pic32_mdio_write(struct mii_dev *bus,
17 int addr, int dev_addr,
18 int reg, u16 value)
19{
20 u32 v;
21 struct pic32_mii_regs *mii_regs = bus->priv;
22
23 /* Wait for the previous operation to finish */
Álvaro Fernández Rojas918de032018-01-23 17:14:55 +010024 wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
25 false, CONFIG_SYS_HZ, true);
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +053026
27 /* Put phyaddr and regaddr into MIIMADD */
28 v = (addr << MIIMADD_PHYADDR_SHIFT) | (reg & MIIMADD_REGADDR);
29 writel(v, &mii_regs->madr.raw);
30
31 /* Initiate a write command */
32 writel(value, &mii_regs->mwtd.raw);
33
34 /* Wait 30 clock cycles for busy flag to be set */
35 udelay(12);
36
37 /* Wait for write to complete */
Álvaro Fernández Rojas918de032018-01-23 17:14:55 +010038 wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
39 false, CONFIG_SYS_HZ, true);
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +053040
41 return 0;
42}
43
44static int pic32_mdio_read(struct mii_dev *bus, int addr, int devaddr, int reg)
45{
46 u32 v;
47 struct pic32_mii_regs *mii_regs = bus->priv;
48
49 /* Wait for the previous operation to finish */
Álvaro Fernández Rojas918de032018-01-23 17:14:55 +010050 wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
51 false, CONFIG_SYS_HZ, true);
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +053052
53 /* Put phyaddr and regaddr into MIIMADD */
54 v = (addr << MIIMADD_PHYADDR_SHIFT) | (reg & MIIMADD_REGADDR);
55 writel(v, &mii_regs->madr.raw);
56
57 /* Initiate a read command */
58 writel(MIIMCMD_READ, &mii_regs->mcmd.raw);
59
60 /* Wait 30 clock cycles for busy flag to be set */
61 udelay(12);
62
63 /* Wait for read to complete */
Álvaro Fernández Rojas918de032018-01-23 17:14:55 +010064 wait_for_bit_le32(&mii_regs->mind.raw,
65 MIIMIND_NOTVALID | MIIMIND_BUSY,
66 false, CONFIG_SYS_HZ, false);
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +053067
68 /* Clear the command register */
69 writel(0, &mii_regs->mcmd.raw);
70
71 /* Grab the value read from the PHY */
72 v = readl(&mii_regs->mrdd.raw);
73 return v;
74}
75
76static int pic32_mdio_reset(struct mii_dev *bus)
77{
78 struct pic32_mii_regs *mii_regs = bus->priv;
79
80 /* Reset MII (due to new addresses) */
81 writel(MIIMCFG_RSTMGMT, &mii_regs->mcfg.raw);
82
83 /* Wait for the operation to finish */
Álvaro Fernández Rojas918de032018-01-23 17:14:55 +010084 wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +053085 false, CONFIG_SYS_HZ, true);
86
87 /* Clear reset bit */
88 writel(0, &mii_regs->mcfg);
89
90 /* Wait for the operation to finish */
Álvaro Fernández Rojas918de032018-01-23 17:14:55 +010091 wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
92 false, CONFIG_SYS_HZ, true);
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +053093
94 /* Set the MII Management Clock (MDC) - no faster than 2.5 MHz */
95 writel(MIIMCFG_CLKSEL_DIV40, &mii_regs->mcfg.raw);
96
97 /* Wait for the operation to finish */
Álvaro Fernández Rojas918de032018-01-23 17:14:55 +010098 wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
99 false, CONFIG_SYS_HZ, true);
Purna Chandra Mandal6b731c92016-01-28 15:30:21 +0530100 return 0;
101}
102
103int pic32_mdio_init(const char *name, ulong ioaddr)
104{
105 struct mii_dev *bus;
106
107 bus = mdio_alloc();
108 if (!bus) {
109 printf("Failed to allocate PIC32-MDIO bus\n");
110 return -ENOMEM;
111 }
112
113 bus->read = pic32_mdio_read;
114 bus->write = pic32_mdio_write;
115 bus->reset = pic32_mdio_reset;
116 strncpy(bus->name, name, sizeof(bus->name));
117 bus->priv = (void *)ioaddr;
118
119 return mdio_register(bus);
120}