net: stmmac:sti: Add STi SOC glue driver.
STi series SOCs have a glue layer on top of the synopsis gmac IP, this
glue layer needs to be configured before the gmac driver starts using
the IP.
This patch adds a support to this glue layer which is configured via
stmmac setup, init, exit callbacks.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c
new file mode 100644
index 0000000..552bbc1
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c
@@ -0,0 +1,330 @@
+/**
+ * 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,
+};