/**
* dwmac-sti.c - STMicroelectronics DWMAC Specific Glue layer
*
* Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
* Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/stmmac.h>
#include <linux/phy.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_net.h>
/**
* STi GMAC glue logic.
* --------------------
*
* _
* | \
* --------|0 \ ETH_SEL_INTERNAL_NOTEXT_PHYCLK
* phyclk | |___________________________________________
* | | | (phyclk-in)
* --------|1 / |
* int-clk |_ / |
* | _
* | | \
* |_______|1 \ ETH_SEL_TX_RETIME_CLK
* | |___________________________
* | | (tx-retime-clk)
* _______|0 /
* | |_ /
* _ |
* | \ |
* --------|0 \ |
* clk_125 | |__|
* | | ETH_SEL_TXCLK_NOT_CLK125
* --------|1 /
* txclk |_ /
*
*
* ETH_SEL_INTERNAL_NOTEXT_PHYCLK is valid only for RMII where PHY can
* generate 50MHz clock or MAC can generate it.
* This bit is configured by "st,ext-phyclk" property.
*
* ETH_SEL_TXCLK_NOT_CLK125 is only valid for gigabit modes, where the 125Mhz
* clock either comes from clk-125 pin or txclk pin. This configuration is
* totally driven by the board wiring. This bit is configured by
* "st,tx-retime-src" property.
*
* TXCLK configuration is different for different phy interface modes
* and changes according to link speed in modes like RGMII.
*
* Below table summarizes the clock requirement and clock sources for
* supported phy interface modes with link speeds.
* ________________________________________________
*| PHY_MODE | 1000 Mbit Link | 100 Mbit Link |
* ------------------------------------------------
*| MII | n/a | 25Mhz |
*| | | txclk |
* ------------------------------------------------
*| GMII | 125Mhz | 25Mhz |
*| | clk-125/txclk | txclk |
* ------------------------------------------------
*| RGMII | 125Mhz | 25Mhz |
*| | clk-125/txclk | clkgen |
* ------------------------------------------------
*| RMII | n/a | 25Mhz |
*| | |clkgen/phyclk-in |
* ------------------------------------------------
*
* TX lines are always retimed with a clk, which can vary depending
* on the board configuration. Below is the table of these bits
* in eth configuration register depending on source of retime clk.
*
*---------------------------------------------------------------
* src | tx_rt_clk | int_not_ext_phyclk | txclk_n_clk125|
*---------------------------------------------------------------
* txclk | 0 | n/a | 1 |
*---------------------------------------------------------------
* ck_125| 0 | n/a | 0 |
*---------------------------------------------------------------
* phyclk| 1 | 0 | n/a |
*---------------------------------------------------------------
* clkgen| 1 | 1 | n/a |
*---------------------------------------------------------------
*/
/* Register definition */
/* 3 bits [8:6]
* [6:6] ETH_SEL_TXCLK_NOT_CLK125
* [7:7] ETH_SEL_INTERNAL_NOTEXT_PHYCLK
* [8:8] ETH_SEL_TX_RETIME_CLK
*
*/
#define TX_RETIME_SRC_MASK GENMASK(8, 6)
#define ETH_SEL_TX_RETIME_CLK BIT(8)
#define ETH_SEL_INTERNAL_NOTEXT_PHYCLK BIT(7)
#define ETH_SEL_TXCLK_NOT_CLK125 BIT(6)
#define ENMII_MASK GENMASK(5, 5)
#define ENMII BIT(5)
/**
* 3 bits [4:2]
* 000-GMII/MII
* 001-RGMII
* 010-SGMII
* 100-RMII
*/
#define MII_PHY_SEL_MASK GENMASK(4, 2)
#define ETH_PHY_SEL_RMII BIT(4)
#define ETH_PHY_SEL_SGMII BIT(3)
#define ETH_PHY_SEL_RGMII BIT(2)
#define ETH_PHY_SEL_GMII 0x0
#define ETH_PHY_SEL_MII 0x0
#define IS_PHY_IF_MODE_RGMII(iface) (iface == PHY_INTERFACE_MODE_RGMII || \
iface == PHY_INTERFACE_MODE_RGMII_ID || \
iface == PHY_INTERFACE_MODE_RGMII_RXID || \
iface == PHY_INTERFACE_MODE_RGMII_TXID)
#define IS_PHY_IF_MODE_GBIT(iface) (IS_PHY_IF_MODE_RGMII(iface) || \
iface == PHY_INTERFACE_MODE_GMII)
struct sti_dwmac {
int interface;
bool ext_phyclk;
bool is_tx_retime_src_clk_125;
struct clk *clk;
int reg;
struct device *dev;
struct regmap *regmap;
};
static u32 phy_intf_sels[] = {
[PHY_INTERFACE_MODE_MII] = ETH_PHY_SEL_MII,
[PHY_INTERFACE_MODE_GMII] = ETH_PHY_SEL_GMII,
[PHY_INTERFACE_MODE_RGMII] = ETH_PHY_SEL_RGMII,
[PHY_INTERFACE_MODE_RGMII_ID] = ETH_PHY_SEL_RGMII,
[PHY_INTERFACE_MODE_SGMII] = ETH_PHY_SEL_SGMII,
[PHY_INTERFACE_MODE_RMII] = ETH_PHY_SEL_RMII,
};
enum {
TX_RETIME_SRC_NA = 0,
TX_RETIME_SRC_TXCLK = 1,
TX_RETIME_SRC_CLK_125,
TX_RETIME_SRC_PHYCLK,
TX_RETIME_SRC_CLKGEN,
};
static const char *const tx_retime_srcs[] = {
[TX_RETIME_SRC_NA] = "",
[TX_RETIME_SRC_TXCLK] = "txclk",
[TX_RETIME_SRC_CLK_125] = "clk_125",
[TX_RETIME_SRC_PHYCLK] = "phyclk",
[TX_RETIME_SRC_CLKGEN] = "clkgen",
};
static u32 tx_retime_val[] = {
[TX_RETIME_SRC_TXCLK] = ETH_SEL_TXCLK_NOT_CLK125,
[TX_RETIME_SRC_CLK_125] = 0x0,
[TX_RETIME_SRC_PHYCLK] = ETH_SEL_TX_RETIME_CLK,
[TX_RETIME_SRC_CLKGEN] = ETH_SEL_TX_RETIME_CLK |
ETH_SEL_INTERNAL_NOTEXT_PHYCLK,
};
static void setup_retime_src(struct sti_dwmac *dwmac, u32 spd)
{
u32 src = 0, freq = 0;
if (spd == SPEED_100) {
if (dwmac->interface == PHY_INTERFACE_MODE_MII ||
dwmac->interface == PHY_INTERFACE_MODE_GMII) {
src = TX_RETIME_SRC_TXCLK;
} else if (dwmac->interface == PHY_INTERFACE_MODE_RMII) {
if (dwmac->ext_phyclk) {
src = TX_RETIME_SRC_PHYCLK;
} else {
src = TX_RETIME_SRC_CLKGEN;
freq = 50000000;
}
} else if (IS_PHY_IF_MODE_RGMII(dwmac->interface)) {
src = TX_RETIME_SRC_CLKGEN;
freq = 25000000;
}
if (src == TX_RETIME_SRC_CLKGEN && dwmac->clk)
clk_set_rate(dwmac->clk, freq);
} else if (spd == SPEED_1000) {
if (dwmac->is_tx_retime_src_clk_125)
src = TX_RETIME_SRC_CLK_125;
else
src = TX_RETIME_SRC_TXCLK;
}
regmap_update_bits(dwmac->regmap, dwmac->reg,
TX_RETIME_SRC_MASK, tx_retime_val[src]);
}
static void sti_dwmac_exit(struct platform_device *pdev, void *priv)
{
struct sti_dwmac *dwmac = priv;
if (dwmac->clk)
clk_disable_unprepare(dwmac->clk);
}
static void sti_fix_mac_speed(void *priv, unsigned int spd)
{
struct sti_dwmac *dwmac = priv;
setup_retime_src(dwmac, spd);
return;
}
static int sti_dwmac_parse_data(struct sti_dwmac *dwmac,
struct platform_device *pdev)
{
struct resource *res;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct regmap *regmap;
int err;
if (!np)
return -EINVAL;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sti-ethconf");
if (!res)
return -ENODATA;
regmap = syscon_regmap_lookup_by_phandle(np, "st,syscon");
if (IS_ERR(regmap))
return PTR_ERR(regmap);
dwmac->dev = dev;
dwmac->interface = of_get_phy_mode(np);
dwmac->regmap = regmap;
dwmac->reg = res->start;
dwmac->ext_phyclk = of_property_read_bool(np, "st,ext-phyclk");
dwmac->is_tx_retime_src_clk_125 = false;
if (IS_PHY_IF_MODE_GBIT(dwmac->interface)) {
const char *rs;
err = of_property_read_string(np, "st,tx-retime-src", &rs);
if (err < 0) {
dev_err(dev, "st,tx-retime-src not specified\n");
return err;
}
if (!strcasecmp(rs, "clk_125"))
dwmac->is_tx_retime_src_clk_125 = true;
}
dwmac->clk = devm_clk_get(dev, "sti-ethclk");
if (IS_ERR(dwmac->clk))
dwmac->clk = NULL;
return 0;
}
static int sti_dwmac_init(struct platform_device *pdev, void *priv)
{
struct sti_dwmac *dwmac = priv;
struct regmap *regmap = dwmac->regmap;
int iface = dwmac->interface;
u32 reg = dwmac->reg;
u32 val, spd;
if (dwmac->clk)
clk_prepare_enable(dwmac->clk);
regmap_update_bits(regmap, reg, MII_PHY_SEL_MASK, phy_intf_sels[iface]);
val = (iface == PHY_INTERFACE_MODE_REVMII) ? 0 : ENMII;
regmap_update_bits(regmap, reg, ENMII_MASK, val);
if (IS_PHY_IF_MODE_GBIT(iface))
spd = SPEED_1000;
else
spd = SPEED_100;
setup_retime_src(dwmac, spd);
return 0;
}
static void *sti_dwmac_setup(struct platform_device *pdev)
{
struct sti_dwmac *dwmac;
int ret;
dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
if (!dwmac)
return ERR_PTR(-ENOMEM);
ret = sti_dwmac_parse_data(dwmac, pdev);
if (ret) {
dev_err(&pdev->dev, "Unable to parse OF data\n");
return ERR_PTR(ret);
}
return dwmac;
}
const struct stmmac_of_data sti_gmac_data = {
.fix_mac_speed = sti_fix_mac_speed,
.setup = sti_dwmac_setup,
.init = sti_dwmac_init,
.exit = sti_dwmac_exit,
};
