Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com) |
| 4 | * |
| 5 | * MDIO implementation for ARC EMAC |
| 6 | */ |
| 7 | |
| 8 | #include <linux/delay.h> |
| 9 | #include <linux/of_mdio.h> |
| 10 | #include <linux/platform_device.h> |
Caesar Wang | 1bddd96 | 2016-03-14 16:01:54 +0800 | [diff] [blame] | 11 | #include <linux/gpio/consumer.h> |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 12 | |
| 13 | #include "emac.h" |
| 14 | |
| 15 | /* Number of seconds we wait for "MDIO complete" flag to appear */ |
| 16 | #define ARC_MDIO_COMPLETE_POLL_COUNT 1 |
| 17 | |
| 18 | /** |
| 19 | * arc_mdio_complete_wait - Waits until MDIO transaction is completed. |
| 20 | * @priv: Pointer to ARC EMAC private data structure. |
| 21 | * |
| 22 | * returns: 0 on success, -ETIMEDOUT on a timeout. |
| 23 | */ |
| 24 | static int arc_mdio_complete_wait(struct arc_emac_priv *priv) |
| 25 | { |
| 26 | unsigned int i; |
| 27 | |
| 28 | for (i = 0; i < ARC_MDIO_COMPLETE_POLL_COUNT * 40; i++) { |
| 29 | unsigned int status = arc_reg_get(priv, R_STATUS); |
| 30 | |
| 31 | status &= MDIO_MASK; |
| 32 | |
| 33 | if (status) { |
| 34 | /* Reset "MDIO complete" flag */ |
| 35 | arc_reg_set(priv, R_STATUS, status); |
| 36 | return 0; |
| 37 | } |
| 38 | |
| 39 | msleep(25); |
| 40 | } |
| 41 | |
| 42 | return -ETIMEDOUT; |
| 43 | } |
| 44 | |
| 45 | /** |
| 46 | * arc_mdio_read - MDIO interface read function. |
| 47 | * @bus: Pointer to MII bus structure. |
| 48 | * @phy_addr: Address of the PHY device. |
| 49 | * @reg_num: PHY register to read. |
| 50 | * |
| 51 | * returns: The register contents on success, -ETIMEDOUT on a timeout. |
| 52 | * |
| 53 | * Reads the contents of the requested register from the requested PHY |
| 54 | * address. |
| 55 | */ |
| 56 | static int arc_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num) |
| 57 | { |
| 58 | struct arc_emac_priv *priv = bus->priv; |
| 59 | unsigned int value; |
| 60 | int error; |
| 61 | |
| 62 | arc_reg_set(priv, R_MDIO, |
| 63 | 0x60020000 | (phy_addr << 23) | (reg_num << 18)); |
| 64 | |
| 65 | error = arc_mdio_complete_wait(priv); |
| 66 | if (error < 0) |
| 67 | return error; |
| 68 | |
| 69 | value = arc_reg_get(priv, R_MDIO) & 0xffff; |
| 70 | |
| 71 | dev_dbg(priv->dev, "arc_mdio_read(phy_addr=%i, reg_num=%x) = %x\n", |
| 72 | phy_addr, reg_num, value); |
| 73 | |
| 74 | return value; |
| 75 | } |
| 76 | |
| 77 | /** |
| 78 | * arc_mdio_write - MDIO interface write function. |
| 79 | * @bus: Pointer to MII bus structure. |
| 80 | * @phy_addr: Address of the PHY device. |
| 81 | * @reg_num: PHY register to write to. |
| 82 | * @value: Value to be written into the register. |
| 83 | * |
| 84 | * returns: 0 on success, -ETIMEDOUT on a timeout. |
| 85 | * |
| 86 | * Writes the value to the requested register. |
| 87 | */ |
| 88 | static int arc_mdio_write(struct mii_bus *bus, int phy_addr, |
| 89 | int reg_num, u16 value) |
| 90 | { |
| 91 | struct arc_emac_priv *priv = bus->priv; |
| 92 | |
| 93 | dev_dbg(priv->dev, |
| 94 | "arc_mdio_write(phy_addr=%i, reg_num=%x, value=%x)\n", |
| 95 | phy_addr, reg_num, value); |
| 96 | |
| 97 | arc_reg_set(priv, R_MDIO, |
Caesar Wang | 663713e | 2016-03-14 16:01:55 +0800 | [diff] [blame] | 98 | 0x50020000 | (phy_addr << 23) | (reg_num << 18) | value); |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 99 | |
| 100 | return arc_mdio_complete_wait(priv); |
| 101 | } |
| 102 | |
| 103 | /** |
Caesar Wang | 1bddd96 | 2016-03-14 16:01:54 +0800 | [diff] [blame] | 104 | * arc_mdio_reset |
| 105 | * @bus: points to the mii_bus structure |
| 106 | * Description: reset the MII bus |
| 107 | */ |
Baoyou Xie | 3f59199 | 2016-09-06 16:21:56 +0800 | [diff] [blame] | 108 | static int arc_mdio_reset(struct mii_bus *bus) |
Caesar Wang | 1bddd96 | 2016-03-14 16:01:54 +0800 | [diff] [blame] | 109 | { |
| 110 | struct arc_emac_priv *priv = bus->priv; |
| 111 | struct arc_emac_mdio_bus_data *data = &priv->bus_data; |
| 112 | |
| 113 | if (data->reset_gpio) { |
| 114 | gpiod_set_value_cansleep(data->reset_gpio, 1); |
| 115 | msleep(data->msec); |
| 116 | gpiod_set_value_cansleep(data->reset_gpio, 0); |
| 117 | } |
| 118 | |
| 119 | return 0; |
| 120 | } |
| 121 | |
| 122 | /** |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 123 | * arc_mdio_probe - MDIO probe function. |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 124 | * @priv: Pointer to ARC EMAC private data structure. |
| 125 | * |
| 126 | * returns: 0 on success, -ENOMEM when mdiobus_alloc |
| 127 | * (to allocate memory for MII bus structure) fails. |
| 128 | * |
| 129 | * Sets up and registers the MDIO interface. |
| 130 | */ |
Romain Perier | 93e91b3 | 2014-08-26 13:14:50 +0000 | [diff] [blame] | 131 | int arc_mdio_probe(struct arc_emac_priv *priv) |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 132 | { |
Caesar Wang | 1bddd96 | 2016-03-14 16:01:54 +0800 | [diff] [blame] | 133 | struct arc_emac_mdio_bus_data *data = &priv->bus_data; |
| 134 | struct device_node *np = priv->dev->of_node; |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 135 | struct mii_bus *bus; |
| 136 | int error; |
| 137 | |
| 138 | bus = mdiobus_alloc(); |
| 139 | if (!bus) |
| 140 | return -ENOMEM; |
| 141 | |
| 142 | priv->bus = bus; |
| 143 | bus->priv = priv; |
| 144 | bus->parent = priv->dev; |
Marek Vasut | 3424d9b | 2016-05-26 00:40:05 +0200 | [diff] [blame] | 145 | bus->name = "Synopsys MII Bus"; |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 146 | bus->read = &arc_mdio_read; |
| 147 | bus->write = &arc_mdio_write; |
Caesar Wang | 1bddd96 | 2016-03-14 16:01:54 +0800 | [diff] [blame] | 148 | bus->reset = &arc_mdio_reset; |
| 149 | |
| 150 | /* optional reset-related properties */ |
| 151 | data->reset_gpio = devm_gpiod_get_optional(priv->dev, "phy-reset", |
| 152 | GPIOD_OUT_LOW); |
| 153 | if (IS_ERR(data->reset_gpio)) { |
| 154 | error = PTR_ERR(data->reset_gpio); |
| 155 | dev_err(priv->dev, "Failed to request gpio: %d\n", error); |
| 156 | return error; |
| 157 | } |
| 158 | |
| 159 | of_property_read_u32(np, "phy-reset-duration", &data->msec); |
| 160 | /* A sane reset duration should not be longer than 1s */ |
| 161 | if (data->msec > 1000) |
| 162 | data->msec = 1; |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 163 | |
Romain Perier | 93e91b3 | 2014-08-26 13:14:50 +0000 | [diff] [blame] | 164 | snprintf(bus->id, MII_BUS_ID_SIZE, "%s", bus->name); |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 165 | |
Romain Perier | 93e91b3 | 2014-08-26 13:14:50 +0000 | [diff] [blame] | 166 | error = of_mdiobus_register(bus, priv->dev->of_node); |
Alexey Brodkin | e4f2379 | 2013-06-24 09:54:27 +0400 | [diff] [blame] | 167 | if (error) { |
| 168 | dev_err(priv->dev, "cannot register MDIO bus %s\n", bus->name); |
| 169 | mdiobus_free(bus); |
| 170 | return error; |
| 171 | } |
| 172 | |
| 173 | return 0; |
| 174 | } |
| 175 | |
| 176 | /** |
| 177 | * arc_mdio_remove - MDIO remove function. |
| 178 | * @priv: Pointer to ARC EMAC private data structure. |
| 179 | * |
| 180 | * Unregisters the MDIO and frees any associate memory for MII bus. |
| 181 | */ |
| 182 | int arc_mdio_remove(struct arc_emac_priv *priv) |
| 183 | { |
| 184 | mdiobus_unregister(priv->bus); |
| 185 | mdiobus_free(priv->bus); |
| 186 | priv->bus = NULL; |
| 187 | |
| 188 | return 0; |
| 189 | } |