Purna Chandra Mandal | 6b731c9 | 2016-01-28 15:30:21 +0530 | [diff] [blame] | 1 | /* |
| 2 | * pic32_mdio.c: PIC32 MDIO/MII driver, part of pic32_eth.c. |
| 3 | * |
| 4 | * Copyright 2015 Microchip Inc. |
| 5 | * Purna Chandra Mandal <purna.mandal@microchip.com> |
| 6 | * |
| 7 | * SPDX-License-Identifier: GPL-2.0+ |
| 8 | */ |
| 9 | #include <common.h> |
| 10 | #include <phy.h> |
| 11 | #include <miiphy.h> |
| 12 | #include <errno.h> |
| 13 | #include <wait_bit.h> |
| 14 | #include <asm/io.h> |
| 15 | #include "pic32_eth.h" |
| 16 | |
| 17 | static int pic32_mdio_write(struct mii_dev *bus, |
| 18 | int addr, int dev_addr, |
| 19 | int reg, u16 value) |
| 20 | { |
| 21 | u32 v; |
| 22 | struct pic32_mii_regs *mii_regs = bus->priv; |
| 23 | |
| 24 | /* Wait for the previous operation to finish */ |
| 25 | wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY, |
| 26 | false, CONFIG_SYS_HZ, true); |
| 27 | |
| 28 | /* Put phyaddr and regaddr into MIIMADD */ |
| 29 | v = (addr << MIIMADD_PHYADDR_SHIFT) | (reg & MIIMADD_REGADDR); |
| 30 | writel(v, &mii_regs->madr.raw); |
| 31 | |
| 32 | /* Initiate a write command */ |
| 33 | writel(value, &mii_regs->mwtd.raw); |
| 34 | |
| 35 | /* Wait 30 clock cycles for busy flag to be set */ |
| 36 | udelay(12); |
| 37 | |
| 38 | /* Wait for write to complete */ |
| 39 | wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY, |
| 40 | false, CONFIG_SYS_HZ, true); |
| 41 | |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | static int pic32_mdio_read(struct mii_dev *bus, int addr, int devaddr, int reg) |
| 46 | { |
| 47 | u32 v; |
| 48 | struct pic32_mii_regs *mii_regs = bus->priv; |
| 49 | |
| 50 | /* Wait for the previous operation to finish */ |
| 51 | wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY, |
| 52 | false, CONFIG_SYS_HZ, true); |
| 53 | |
| 54 | /* Put phyaddr and regaddr into MIIMADD */ |
| 55 | v = (addr << MIIMADD_PHYADDR_SHIFT) | (reg & MIIMADD_REGADDR); |
| 56 | writel(v, &mii_regs->madr.raw); |
| 57 | |
| 58 | /* Initiate a read command */ |
| 59 | writel(MIIMCMD_READ, &mii_regs->mcmd.raw); |
| 60 | |
| 61 | /* Wait 30 clock cycles for busy flag to be set */ |
| 62 | udelay(12); |
| 63 | |
| 64 | /* Wait for read to complete */ |
| 65 | wait_for_bit(__func__, &mii_regs->mind.raw, |
| 66 | MIIMIND_NOTVALID | MIIMIND_BUSY, |
| 67 | false, CONFIG_SYS_HZ, false); |
| 68 | |
| 69 | /* Clear the command register */ |
| 70 | writel(0, &mii_regs->mcmd.raw); |
| 71 | |
| 72 | /* Grab the value read from the PHY */ |
| 73 | v = readl(&mii_regs->mrdd.raw); |
| 74 | return v; |
| 75 | } |
| 76 | |
| 77 | static int pic32_mdio_reset(struct mii_dev *bus) |
| 78 | { |
| 79 | struct pic32_mii_regs *mii_regs = bus->priv; |
| 80 | |
| 81 | /* Reset MII (due to new addresses) */ |
| 82 | writel(MIIMCFG_RSTMGMT, &mii_regs->mcfg.raw); |
| 83 | |
| 84 | /* Wait for the operation to finish */ |
| 85 | wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY, |
| 86 | false, CONFIG_SYS_HZ, true); |
| 87 | |
| 88 | /* Clear reset bit */ |
| 89 | writel(0, &mii_regs->mcfg); |
| 90 | |
| 91 | /* Wait for the operation to finish */ |
| 92 | wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY, |
| 93 | false, CONFIG_SYS_HZ, true); |
| 94 | |
| 95 | /* Set the MII Management Clock (MDC) - no faster than 2.5 MHz */ |
| 96 | writel(MIIMCFG_CLKSEL_DIV40, &mii_regs->mcfg.raw); |
| 97 | |
| 98 | /* Wait for the operation to finish */ |
| 99 | wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY, |
| 100 | false, CONFIG_SYS_HZ, true); |
| 101 | return 0; |
| 102 | } |
| 103 | |
| 104 | int pic32_mdio_init(const char *name, ulong ioaddr) |
| 105 | { |
| 106 | struct mii_dev *bus; |
| 107 | |
| 108 | bus = mdio_alloc(); |
| 109 | if (!bus) { |
| 110 | printf("Failed to allocate PIC32-MDIO bus\n"); |
| 111 | return -ENOMEM; |
| 112 | } |
| 113 | |
| 114 | bus->read = pic32_mdio_read; |
| 115 | bus->write = pic32_mdio_write; |
| 116 | bus->reset = pic32_mdio_reset; |
| 117 | strncpy(bus->name, name, sizeof(bus->name)); |
| 118 | bus->priv = (void *)ioaddr; |
| 119 | |
| 120 | return mdio_register(bus); |
| 121 | } |