[PATCH v2 2/4] net: stmmac: dwc-qos: Add FSD EQoS support

[Sriranjani P]

The FSD SoC contains two instance of the Synopsys DWC ethernet QOS IP core.
The binding that it uses is slightly different from existing ones because
of the integration (clocks, resets).

For FSD SoC, a mux switch is needed between internal and external clocks.
By default after reset internal clock is used but for receiving packets
properly, external clock is needed. Mux switch to external clock happens
only when the external clock is present.

Signed-off-by: Chandrasekar R <rcsekar@xxxxxxxxxxx>
Signed-off-by: Suresh Siddha <ssiddha@xxxxxxxxx>
Signed-off-by: Sriranjani P <sriranjani.p@xxxxxxxxxxx>
---
 .../stmicro/stmmac/dwmac-dwc-qos-eth.c        | 174 ++++++++++++++++++
 .../net/ethernet/stmicro/stmmac/stmmac_main.c |  24 +++
 include/linux/stmmac.h                        |   1 +
 3 files changed, 199 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
index 358fc26f8d1f..e41b6e849a9d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
@@ -20,6 +20,7 @@
 #include <linux/platform_device.h>
 #include <linux/reset.h>
 #include <linux/stmmac.h>
+#include <linux/regmap.h>
 
 #include "stmmac_platform.h"
 #include "dwmac4.h"
@@ -37,6 +38,45 @@ struct tegra_eqos {
 	struct gpio_desc *reset;
 };
 
+enum fsd_rxmux_clk {
+	FSD_RXCLK_MUX = 7,
+	FSD_RXCLK_EXTERNAL,
+	FSD_RXCLK_INTERNAL
+};
+
+struct fsd_eqos_plat_data {
+	const struct fsd_eqos_variant *fsd_eqos_instance_variant;
+	struct clk_bulk_data *clks;
+	struct device *dev;
+};
+
+struct fsd_eqos_variant {
+	const char * const *clk_list;
+	int num_clks;
+};
+
+static const char * const fsd_eqos_instance_0_clk[] = {
+	"ptp_ref", "master_bus", "slave_bus", "tx", "rx"
+};
+
+static const char * const fsd_eqos_instance_1_clk[] = {
+	"ptp_ref", "master_bus", "slave_bus", "tx", "rx", "master2_bus",
+	"slave2_bus", "eqos_rxclk_mux", "eqos_phyrxclk", "dout_peric_rgmii_clk"
+};
+
+static const int rx_clock_skew_val[] = {0x2, 0x0};
+
+static const struct fsd_eqos_variant fsd_eqos_clk_info[] = {
+	{
+		.clk_list = fsd_eqos_instance_0_clk,
+		.num_clks = ARRAY_SIZE(fsd_eqos_instance_0_clk)
+	},
+	{
+		.clk_list = fsd_eqos_instance_1_clk,
+		.num_clks = ARRAY_SIZE(fsd_eqos_instance_1_clk)
+	},
+};
+
 static int dwc_eth_dwmac_config_dt(struct platform_device *pdev,
 				   struct plat_stmmacenet_data *plat_dat)
 {
@@ -267,6 +307,134 @@ static int tegra_eqos_init(struct platform_device *pdev, void *priv)
 	return 0;
 }
 
+static int dwc_eqos_rxmux_setup(void *priv, bool external)
+{
+	struct fsd_eqos_plat_data *plat = priv;
+
+	/* doesn't support RX clock mux */
+	if (!plat->clks[FSD_RXCLK_MUX].clk)
+		return 0;
+
+	if (external)
+		return clk_set_parent(plat->clks[FSD_RXCLK_MUX].clk,
+				      plat->clks[FSD_RXCLK_EXTERNAL].clk);
+	else
+		return clk_set_parent(plat->clks[FSD_RXCLK_MUX].clk,
+				      plat->clks[FSD_RXCLK_INTERNAL].clk);
+}
+
+static int dwc_eqos_setup_rxclock(struct platform_device *pdev, int ins_num)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct regmap *syscon;
+	unsigned int reg;
+
+	if (np && of_property_read_bool(np, "rx-clock-skew")) {
+		syscon = syscon_regmap_lookup_by_phandle_args(np,
+				"rx-clock-skew", 1, &reg);
+		if (IS_ERR(syscon)) {
+			dev_err(&pdev->dev,
+				"couldn't get the rx-clock-skew syscon!\n");
+			return PTR_ERR(syscon);
+		}
+
+		regmap_write(syscon, reg, rx_clock_skew_val[ins_num]);
+	}
+
+	return 0;
+}
+
+static int fsd_eqos_clk_init(struct fsd_eqos_plat_data *plat,
+			     struct plat_stmmacenet_data *data)
+{
+	int ret = 0, i;
+
+	const struct fsd_eqos_variant *fsd_eqos_variant_data =
+						plat->fsd_eqos_instance_variant;
+
+	plat->clks = devm_kcalloc(plat->dev, fsd_eqos_variant_data->num_clks,
+				  sizeof(*plat->clks), GFP_KERNEL);
+	if (!plat->clks)
+		return -ENOMEM;
+
+	for (i = 0; i < fsd_eqos_variant_data->num_clks; i++)
+		plat->clks[i].id = fsd_eqos_variant_data->clk_list[i];
+
+	ret = devm_clk_bulk_get(plat->dev, fsd_eqos_variant_data->num_clks,
+				plat->clks);
+
+	return ret;
+}
+
+static int fsd_clks_endisable(void *priv, bool enabled)
+{
+	int ret, num_clks;
+	struct fsd_eqos_plat_data *plat = priv;
+
+	num_clks = plat->fsd_eqos_instance_variant->num_clks;
+
+	if (enabled) {
+		ret = clk_bulk_prepare_enable(num_clks, plat->clks);
+		if (ret) {
+			dev_err(plat->dev, "Clock enable failed, err = %d\n", ret);
+			return ret;
+		}
+	} else {
+		clk_bulk_disable_unprepare(num_clks, plat->clks);
+	}
+
+	return 0;
+}
+
+static int fsd_eqos_probe(struct platform_device *pdev,
+			  struct plat_stmmacenet_data *data,
+			  struct stmmac_resources *res)
+{
+	struct fsd_eqos_plat_data *priv_plat;
+	struct device_node *np = pdev->dev.of_node;
+	int ret = 0;
+
+	priv_plat = devm_kzalloc(&pdev->dev, sizeof(*priv_plat), GFP_KERNEL);
+	if (!priv_plat) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	priv_plat->dev = &pdev->dev;
+	data->bus_id = of_alias_get_id(np, "eth");
+
+	priv_plat->fsd_eqos_instance_variant = &fsd_eqos_clk_info[data->bus_id];
+
+	ret = fsd_eqos_clk_init(priv_plat, data);
+
+	data->bsp_priv = priv_plat;
+	data->clks_config = fsd_clks_endisable;
+	data->rxmux_setup = dwc_eqos_rxmux_setup;
+
+	ret = fsd_clks_endisable(priv_plat, true);
+	if (ret)
+		goto error;
+
+	ret = dwc_eqos_setup_rxclock(pdev, data->bus_id);
+	if (ret) {
+		fsd_clks_endisable(priv_plat, false);
+		dev_err_probe(&pdev->dev, ret, "Unable to setup rxclock\n");
+	}
+
+error:
+	return ret;
+}
+
+static int fsd_eqos_remove(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct fsd_eqos_plat_data *priv_plat = get_stmmac_bsp_priv(&pdev->dev);
+
+	ret = fsd_clks_endisable(priv_plat, false);
+
+	return ret;
+}
+
 static int tegra_eqos_probe(struct platform_device *pdev,
 			    struct plat_stmmacenet_data *data,
 			    struct stmmac_resources *res)
@@ -415,6 +583,11 @@ static const struct dwc_eth_dwmac_data tegra_eqos_data = {
 	.remove = tegra_eqos_remove,
 };
 
+static const struct dwc_eth_dwmac_data fsd_eqos_data = {
+	.probe = fsd_eqos_probe,
+	.remove = fsd_eqos_remove,
+};
+
 static int dwc_eth_dwmac_probe(struct platform_device *pdev)
 {
 	const struct dwc_eth_dwmac_data *data;
@@ -495,6 +668,7 @@ static int dwc_eth_dwmac_remove(struct platform_device *pdev)
 static const struct of_device_id dwc_eth_dwmac_match[] = {
 	{ .compatible = "snps,dwc-qos-ethernet-4.10", .data = &dwc_qos_data },
 	{ .compatible = "nvidia,tegra186-eqos", .data = &tegra_eqos_data },
+	{ .compatible = "tesla,dwc-qos-ethernet-4.21", .data = &fsd_eqos_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, dwc_eth_dwmac_match);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 592d29abcb1c..0330647ca8b6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3821,6 +3821,12 @@ static int __stmmac_open(struct net_device *dev,
 	netif_tx_start_all_queues(priv->dev);
 	stmmac_enable_all_dma_irq(priv);
 
+	if (priv->plat->rxmux_setup) {
+		ret = priv->plat->rxmux_setup(priv->plat->bsp_priv, true);
+		if (ret)
+			netdev_err(priv->dev, "Rxmux setup failed\n");
+	}
+
 	return 0;
 
 irq_error:
@@ -3874,6 +3880,12 @@ static int stmmac_release(struct net_device *dev)
 	struct stmmac_priv *priv = netdev_priv(dev);
 	u32 chan;
 
+	if (priv->plat->rxmux_setup) {
+		ret = priv->plat->rxmux_setup(priv->plat->bsp_priv, false);
+		if (ret)
+			netdev_err(priv->dev, "Rxmux setup failed\n");
+	}
+
 	if (device_may_wakeup(priv->device))
 		phylink_speed_down(priv->phylink, false);
 	/* Stop and disconnect the PHY */
@@ -7397,6 +7409,12 @@ int stmmac_suspend(struct device *dev)
 	if (!ndev || !netif_running(ndev))
 		return 0;
 
+	if (priv->plat->rxmux_setup) {
+		ret = priv->plat->rxmux_setup(priv->plat->bsp_priv, false);
+		if (ret)
+			netdev_err(priv->dev, "Rxmux setup failed\n");
+	}
+
 	mutex_lock(&priv->lock);
 
 	netif_device_detach(ndev);
@@ -7560,6 +7578,12 @@ int stmmac_resume(struct device *dev)
 	mutex_unlock(&priv->lock);
 	rtnl_unlock();
 
+	if (priv->plat->rxmux_setup) {
+		ret = priv->plat->rxmux_setup(priv->plat->bsp_priv, true);
+		if (ret)
+			netdev_err(priv->dev, "Rxmux setup failed\n");
+	}
+
 	netif_device_attach(ndev);
 
 	return 0;
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index fb2e88614f5d..8867646917e0 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -229,6 +229,7 @@ struct plat_stmmacenet_data {
 	void (*ptp_clk_freq_config)(void *priv);
 	int (*init)(struct platform_device *pdev, void *priv);
 	void (*exit)(struct platform_device *pdev, void *priv);
+	int (*rxmux_setup)(void *priv, bool external);
 	struct mac_device_info *(*setup)(void *priv);
 	int (*clks_config)(void *priv, bool enabled);
 	int (*crosststamp)(ktime_t *device, struct system_counterval_t *system,
-- 
2.17.1