rapidio/switches: add driver for IDT gen3 switches

Add RapidIO switch driver for IDT Gen3 switch devices: RXS1632 and
RXS2448.

[[email protected]: fixup for original driver patch]
  Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexandre Bounine <[email protected]>
Tested-by: Barry Wood <[email protected]>
Cc: Matt Porter <[email protected]>
Cc: Andre van Herk <[email protected]>
Cc: Barry Wood <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

drivers/rapidio/switches/Kconfig

@@ -22,3 +22,9 @@ config RAPIDIO_CPS_GEN2
 	default n
 	---help---
 	  Includes support for ITD CPS Gen.2 serial RapidIO switches.
+
+config RAPIDIO_RXS_GEN3
+	tristate "IDT RXS Gen.3 SRIO switch support"
+	default n
+	---help---
+	  Includes support for ITD RXS Gen.3 serial RapidIO switches.

drivers/rapidio/switches/Makefile

@@ -6,3 +6,4 @@ obj-$(CONFIG_RAPIDIO_TSI57X)	+= tsi57x.o
 obj-$(CONFIG_RAPIDIO_CPS_XX)	+= idtcps.o
 obj-$(CONFIG_RAPIDIO_TSI568)	+= tsi568.o
 obj-$(CONFIG_RAPIDIO_CPS_GEN2)	+= idt_gen2.o
+obj-$(CONFIG_RAPIDIO_RXS_GEN3)	+= idt_gen3.o

drivers/rapidio/switches/idt_gen3.c

@@ -0,0 +1,382 @@
+/*
+ * IDT RXS Gen.3 Serial RapidIO switch family support
+ *
+ * Copyright 2016 Integrated Device Technology, Inc.
+ *
+ * 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/stat.h>
+#include <linux/module.h>
+#include <linux/rio.h>
+#include <linux/rio_drv.h>
+#include <linux/rio_ids.h>
+#include <linux/delay.h>
+
+#include <asm/page.h>
+#include "../rio.h"
+
+#define RIO_EM_PW_STAT		0x40020
+#define RIO_PW_CTL		0x40204
+#define RIO_PW_CTL_PW_TMR		0xffffff00
+#define RIO_PW_ROUTE		0x40208
+
+#define RIO_EM_DEV_INT_EN	0x40030
+
+#define RIO_PLM_SPx_IMP_SPEC_CTL(x)	(0x10100 + (x)*0x100)
+#define RIO_PLM_SPx_IMP_SPEC_CTL_SOFT_RST	0x02000000
+
+#define RIO_PLM_SPx_PW_EN(x)	(0x10118 + (x)*0x100)
+#define RIO_PLM_SPx_PW_EN_OK2U	0x40000000
+#define RIO_PLM_SPx_PW_EN_LINIT 0x10000000
+
+#define RIO_BC_L2_Gn_ENTRYx_CSR(n, x)	(0x31000 + (n)*0x400 + (x)*0x4)
+#define RIO_SPx_L2_Gn_ENTRYy_CSR(x, n, y) \
+				(0x51000 + (x)*0x2000 + (n)*0x400 + (y)*0x4)
+
+static int
+idtg3_route_add_entry(struct rio_mport *mport, u16 destid, u8 hopcount,
+		       u16 table, u16 route_destid, u8 route_port)
+{
+	u32 rval;
+	u32 entry = route_port;
+	int err = 0;
+
+	pr_debug("RIO: %s t=0x%x did_%x to p_%x\n",
+		 __func__, table, route_destid, entry);
+
+	if (route_destid > 0xFF)
+		return -EINVAL;
+
+	if (route_port == RIO_INVALID_ROUTE)
+		entry = RIO_RT_ENTRY_DROP_PKT;
+
+	if (table == RIO_GLOBAL_TABLE) {
+		/* Use broadcast register to update all per-port tables */
+		err = rio_mport_write_config_32(mport, destid, hopcount,
+				RIO_BC_L2_Gn_ENTRYx_CSR(0, route_destid),
+				entry);
+		return err;
+	}
+
+	/*
+	 * Verify that specified port/table number is valid
+	 */
+	err = rio_mport_read_config_32(mport, destid, hopcount,
+				       RIO_SWP_INFO_CAR, &rval);
+	if (err)
+		return err;
+
+	if (table >= RIO_GET_TOTAL_PORTS(rval))
+		return -EINVAL;
+
+	err = rio_mport_write_config_32(mport, destid, hopcount,
+			RIO_SPx_L2_Gn_ENTRYy_CSR(table, 0, route_destid),
+			entry);
+	return err;
+}
+
+static int
+idtg3_route_get_entry(struct rio_mport *mport, u16 destid, u8 hopcount,
+		       u16 table, u16 route_destid, u8 *route_port)
+{
+	u32 rval;
+	int err;
+
+	if (route_destid > 0xFF)
+		return -EINVAL;
+
+	err = rio_mport_read_config_32(mport, destid, hopcount,
+				       RIO_SWP_INFO_CAR, &rval);
+	if (err)
+		return err;
+
+	/*
+	 * This switch device does not have the dedicated global routing table.
+	 * It is substituted by reading routing table of the ingress port of
+	 * maintenance read requests.
+	 */
+	if (table == RIO_GLOBAL_TABLE)
+		table = RIO_GET_PORT_NUM(rval);
+	else if (table >= RIO_GET_TOTAL_PORTS(rval))
+		return -EINVAL;
+
+	err = rio_mport_read_config_32(mport, destid, hopcount,
+			RIO_SPx_L2_Gn_ENTRYy_CSR(table, 0, route_destid),
+			&rval);
+	if (err)
+		return err;
+
+	if (rval == RIO_RT_ENTRY_DROP_PKT)
+		*route_port = RIO_INVALID_ROUTE;
+	else
+		*route_port = (u8)rval;
+
+	return 0;
+}
+
+static int
+idtg3_route_clr_table(struct rio_mport *mport, u16 destid, u8 hopcount,
+		       u16 table)
+{
+	u32 i;
+	u32 rval;
+	int err;
+
+	if (table == RIO_GLOBAL_TABLE) {
+		for (i = 0; i <= 0xff; i++) {
+			err = rio_mport_write_config_32(mport, destid, hopcount,
+						RIO_BC_L2_Gn_ENTRYx_CSR(0, i),
+						RIO_RT_ENTRY_DROP_PKT);
+			if (err)
+				break;
+		}
+
+		return err;
+	}
+
+	err = rio_mport_read_config_32(mport, destid, hopcount,
+				       RIO_SWP_INFO_CAR, &rval);
+	if (err)
+		return err;
+
+	if (table >= RIO_GET_TOTAL_PORTS(rval))
+		return -EINVAL;
+
+	for (i = 0; i <= 0xff; i++) {
+		err = rio_mport_write_config_32(mport, destid, hopcount,
+					RIO_SPx_L2_Gn_ENTRYy_CSR(table, 0, i),
+					RIO_RT_ENTRY_DROP_PKT);
+		if (err)
+			break;
+	}
+
+	return err;
+}
+
+/*
+ * This routine performs device-specific initialization only.
+ * All standard EM configuration should be performed at upper level.
+ */
+static int
+idtg3_em_init(struct rio_dev *rdev)
+{
+	int i, tmp;
+	u32 rval;
+
+	pr_debug("RIO: %s [%d:%d]\n", __func__, rdev->destid, rdev->hopcount);
+
+	/* Disable assertion of interrupt signal */
+	rio_write_config_32(rdev, RIO_EM_DEV_INT_EN, 0);
+
+	/* Disable port-write event notifications during initialization */
+	rio_write_config_32(rdev, rdev->em_efptr + RIO_EM_PW_TX_CTRL,
+			    RIO_EM_PW_TX_CTRL_PW_DIS);
+
+	/* Configure Port-Write notifications for hot-swap events */
+	tmp = RIO_GET_TOTAL_PORTS(rdev->swpinfo);
+	for (i = 0; i < tmp; i++) {
+
+		rio_read_config_32(rdev,
+			RIO_DEV_PORT_N_ERR_STS_CSR(rdev, i),
+			&rval);
+		if (rval & RIO_PORT_N_ERR_STS_PORT_UA)
+			continue;
+
+		/* Clear events signaled before enabling notification */
+		rio_write_config_32(rdev,
+			rdev->em_efptr + RIO_EM_PN_ERR_DETECT(i), 0);
+
+		/* Enable event notifications */
+		rio_write_config_32(rdev,
+			rdev->em_efptr + RIO_EM_PN_ERRRATE_EN(i),
+			RIO_EM_PN_ERRRATE_EN_OK2U | RIO_EM_PN_ERRRATE_EN_U2OK);
+		/* Enable port-write generation on events */
+		rio_write_config_32(rdev, RIO_PLM_SPx_PW_EN(i),
+			RIO_PLM_SPx_PW_EN_OK2U | RIO_PLM_SPx_PW_EN_LINIT);
+
+	}
+
+	/* Set Port-Write destination port */
+	tmp = RIO_GET_PORT_NUM(rdev->swpinfo);
+	rio_write_config_32(rdev, RIO_PW_ROUTE, 1 << tmp);
+
+
+	/* Enable sending port-write event notifications */
+	rio_write_config_32(rdev, rdev->em_efptr + RIO_EM_PW_TX_CTRL, 0);
+
+	/* set TVAL = ~50us */
+	rio_write_config_32(rdev,
+		rdev->phys_efptr + RIO_PORT_LINKTO_CTL_CSR, 0x8e << 8);
+	return 0;
+}
+
+
+/*
+ * idtg3_em_handler - device-specific error handler
+ *
+ * If the link is down (PORT_UNINIT) does nothing - this is considered
+ * as link partner removal from the port.
+ *
+ * If the link is up (PORT_OK) - situation is handled as *new* device insertion.
+ * In this case ERR_STOP bits are cleared by issuing soft reset command to the
+ * reporting port. Inbound and outbound ackIDs are cleared by the reset as well.
+ * This way the port is synchronized with freshly inserted device (assuming it
+ * was reset/powered-up on insertion).
+ *
+ * TODO: This is not sufficient in a situation when a link between two devices
+ * was down and up again (e.g. cable disconnect). For that situation full ackID
+ * realignment process has to be implemented.
+ */
+static int
+idtg3_em_handler(struct rio_dev *rdev, u8 pnum)
+{
+	u32 err_status;
+	u32 rval;
+
+	rio_read_config_32(rdev,
+			RIO_DEV_PORT_N_ERR_STS_CSR(rdev, pnum),
+			&err_status);
+
+	/* Do nothing for device/link removal */
+	if (err_status & RIO_PORT_N_ERR_STS_PORT_UNINIT)
+		return 0;
+
+	/* When link is OK we have a device insertion.
+	 * Request port soft reset to clear errors if they present.
+	 * Inbound and outbound ackIDs will be 0 after reset.
+	 */
+	if (err_status & (RIO_PORT_N_ERR_STS_OUT_ES |
+				RIO_PORT_N_ERR_STS_INP_ES)) {
+		rio_read_config_32(rdev, RIO_PLM_SPx_IMP_SPEC_CTL(pnum), &rval);
+		rio_write_config_32(rdev, RIO_PLM_SPx_IMP_SPEC_CTL(pnum),
+				    rval | RIO_PLM_SPx_IMP_SPEC_CTL_SOFT_RST);
+		udelay(10);
+		rio_write_config_32(rdev, RIO_PLM_SPx_IMP_SPEC_CTL(pnum), rval);
+		msleep(500);
+	}
+
+	return 0;
+}
+
+static struct rio_switch_ops idtg3_switch_ops = {
+	.owner = THIS_MODULE,
+	.add_entry = idtg3_route_add_entry,
+	.get_entry = idtg3_route_get_entry,
+	.clr_table = idtg3_route_clr_table,
+	.em_init   = idtg3_em_init,
+	.em_handle = idtg3_em_handler,
+};
+
+static int idtg3_probe(struct rio_dev *rdev, const struct rio_device_id *id)
+{
+	pr_debug("RIO: %s for %s\n", __func__, rio_name(rdev));
+
+	spin_lock(&rdev->rswitch->lock);
+
+	if (rdev->rswitch->ops) {
+		spin_unlock(&rdev->rswitch->lock);
+		return -EINVAL;
+	}
+
+	rdev->rswitch->ops = &idtg3_switch_ops;
+
+	if (rdev->do_enum) {
+		/* Disable hierarchical routing support: Existing fabric
+		 * enumeration/discovery process (see rio-scan.c) uses 8-bit
+		 * flat destination ID routing only.
+		 */
+		rio_write_config_32(rdev, 0x5000 + RIO_BC_RT_CTL_CSR, 0);
+	}
+
+	spin_unlock(&rdev->rswitch->lock);
+
+	return 0;
+}
+
+static void idtg3_remove(struct rio_dev *rdev)
+{
+	pr_debug("RIO: %s for %s\n", __func__, rio_name(rdev));
+	spin_lock(&rdev->rswitch->lock);
+	if (rdev->rswitch->ops == &idtg3_switch_ops)
+		rdev->rswitch->ops = NULL;
+	spin_unlock(&rdev->rswitch->lock);
+}
+
+/*
+ * Gen3 switches repeat sending PW messages until a corresponding event flag
+ * is cleared. Use shutdown notification to disable generation of port-write
+ * messages if their destination node is shut down.
+ */
+static void idtg3_shutdown(struct rio_dev *rdev)
+{
+	int i;
+	u32 rval;
+	u16 destid;
+
+	/* Currently the enumerator node acts also as PW handler */
+	if (!rdev->do_enum)
+		return;
+
+	pr_debug("RIO: %s(%s)\n", __func__, rio_name(rdev));
+
+	rio_read_config_32(rdev, RIO_PW_ROUTE, &rval);
+	i = RIO_GET_PORT_NUM(rdev->swpinfo);
+
+	/* Check port-write destination port */
+	if (!((1 << i) & rval))
+		return;
+
+	/* Disable sending port-write event notifications if PW destID
+	 * matches to one of the enumerator node
+	 */
+	rio_read_config_32(rdev, rdev->em_efptr + RIO_EM_PW_TGT_DEVID, &rval);
+
+	if (rval & RIO_EM_PW_TGT_DEVID_DEV16)
+		destid = rval >> 16;
+	else
+		destid = ((rval & RIO_EM_PW_TGT_DEVID_D8) >> 16);
+
+	if (rdev->net->hport->host_deviceid == destid) {
+		rio_write_config_32(rdev,
+				    rdev->em_efptr + RIO_EM_PW_TX_CTRL, 0);
+		pr_debug("RIO: %s(%s) PW transmission disabled\n",
+			 __func__, rio_name(rdev));
+	}
+}
+
+static struct rio_device_id idtg3_id_table[] = {
+	{RIO_DEVICE(RIO_DID_IDTRXS1632, RIO_VID_IDT)},
+	{RIO_DEVICE(RIO_DID_IDTRXS2448, RIO_VID_IDT)},
+	{ 0, }	/* terminate list */
+};
+
+static struct rio_driver idtg3_driver = {
+	.name = "idt_gen3",
+	.id_table = idtg3_id_table,
+	.probe = idtg3_probe,
+	.remove = idtg3_remove,
+	.shutdown = idtg3_shutdown,
+};
+
+static int __init idtg3_init(void)
+{
+	return rio_register_driver(&idtg3_driver);
+}
+
+static void __exit idtg3_exit(void)
+{
+	pr_debug("RIO: %s\n", __func__);
+	rio_unregister_driver(&idtg3_driver);
+	pr_debug("RIO: %s done\n", __func__);
+}
+
+device_initcall(idtg3_init);
+module_exit(idtg3_exit);
+
+MODULE_DESCRIPTION("IDT RXS Gen.3 Serial RapidIO switch family driver");
+MODULE_AUTHOR("Integrated Device Technology, Inc.");
+MODULE_LICENSE("GPL");