[PATCH V2 net-next] net: fec: add stop mode support for imx8 platform

[wei . fang]

From: Wei Fang <wei.fang@xxxxxxx>

The current driver support stop mode by calling machine api.
The patch add dts support to set GPR register for stop request.

imx8mq enter stop/exit stop mode by setting GPR bit, which can
be accessed by A core.
imx8qm enter stop/exit stop mode by calling IMX_SC ipc APIs that
communicate with M core ipc service, and the M core set the related
GPR bit at last.

Signed-off-by: Wei Fang <wei.fang@xxxxxxx>
---
V2 change:
V1 patch does not apply, so rebase it.
---
 drivers/net/ethernet/freescale/fec.h      |  4 +++
 drivers/net/ethernet/freescale/fec_main.c | 35 +++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 0cebe4b63adb..68bc16058bae 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -18,6 +18,8 @@
 #include <linux/net_tstamp.h>
 #include <linux/ptp_clock_kernel.h>
 #include <linux/timecounter.h>
+#include <dt-bindings/firmware/imx/rsrc.h>
+#include <linux/firmware/imx/sci.h>
 
 #if defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x) || \
     defined(CONFIG_M520x) || defined(CONFIG_M532x) || defined(CONFIG_ARM) || \
@@ -641,6 +643,8 @@ struct fec_enet_private {
 		u8 at_inc_corr;
 	} ptp_saved_state;
 
+	struct imx_sc_ipc *ipc_handle;
+
 	u64 ethtool_stats[];
 };
 
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 7211597d323d..8ba8eb340b92 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1181,6 +1181,34 @@ fec_restart(struct net_device *ndev)
 
 }
 
+static int fec_enet_ipc_handle_init(struct fec_enet_private *fep)
+{
+	if (!(of_machine_is_compatible("fsl,imx8qm") ||
+	      of_machine_is_compatible("fsl,imx8qxp") ||
+	      of_machine_is_compatible("fsl,imx8dxl")))
+		return 0;
+
+	return imx_scu_get_handle(&fep->ipc_handle);
+}
+
+static void fec_enet_ipg_stop_set(struct fec_enet_private *fep, bool enabled)
+{
+	struct device_node *np = fep->pdev->dev.of_node;
+	u32 rsrc_id, val;
+	int idx;
+
+	if (!np || !fep->ipc_handle)
+		return;
+
+	idx = of_alias_get_id(np, "ethernet");
+	if (idx < 0)
+		idx = 0;
+	rsrc_id = idx ? IMX_SC_R_ENET_1 : IMX_SC_R_ENET_0;
+
+	val = enabled ? 1 : 0;
+	imx_sc_misc_set_control(fep->ipc_handle, rsrc_id, IMX_SC_C_IPG_STOP, val);
+}
+
 static void fec_enet_stop_mode(struct fec_enet_private *fep, bool enabled)
 {
 	struct fec_platform_data *pdata = fep->pdev->dev.platform_data;
@@ -1196,6 +1224,8 @@ static void fec_enet_stop_mode(struct fec_enet_private *fep, bool enabled)
 					   BIT(stop_gpr->bit), 0);
 	} else if (pdata && pdata->sleep_mode_enable) {
 		pdata->sleep_mode_enable(enabled);
+	} else {
+		fec_enet_ipg_stop_set(fep, enabled);
 	}
 }
 
@@ -3851,6 +3881,10 @@ fec_probe(struct platform_device *pdev)
 	    !of_property_read_bool(np, "fsl,err006687-workaround-present"))
 		fep->quirks |= FEC_QUIRK_ERR006687;
 
+	ret = fec_enet_ipc_handle_init(fep);
+	if (ret)
+		goto failed_ipc_init;
+
 	if (of_get_property(np, "fsl,magic-packet", NULL))
 		fep->wol_flag |= FEC_WOL_HAS_MAGIC_PACKET;
 
@@ -4048,6 +4082,7 @@ fec_probe(struct platform_device *pdev)
 		of_phy_deregister_fixed_link(np);
 	of_node_put(phy_node);
 failed_stop_mode:
+failed_ipc_init:
 failed_phy:
 	dev_id--;
 failed_ioremap:
-- 
2.25.1