[linux.git] / drivers / fsi / fsi-master-hub.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * FSI hub master driver
 *
 * Copyright (C) IBM Corporation 2016
 */

#include <linux/delay.h>
#include <linux/fsi.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>

#include "fsi-master.h"

#define FSI_ENGID_HUB_MASTER		0x1c

#define FSI_LINK_ENABLE_SETUP_TIME	10	/* in mS */

/*
 * FSI hub master support
 *
 * A hub master increases the number of potential target devices that the
 * primary FSI master can access. For each link a primary master supports,
 * each of those links can in turn be chained to a hub master with multiple
 * links of its own.
 *
 * The hub is controlled by a set of control registers exposed as a regular fsi
 * device (the hub->upstream device), and provides access to the downstream FSI
 * bus as through an address range on the slave itself (->addr and ->size).
 *
 * [This differs from "cascaded" masters, which expose the entire downstream
 * bus entirely through the fsi device address range, and so have a smaller
 * accessible address space.]
 */
struct fsi_master_hub {
	struct fsi_master	master;
	struct fsi_device	*upstream;
	uint32_t		addr, size;	/* slave-relative addr of */
						/* master address space */
};

#define to_fsi_master_hub(m) container_of(m, struct fsi_master_hub, master)

static int hub_master_read(struct fsi_master *master, int link,
			uint8_t id, uint32_t addr, void *val, size_t size)
{
	struct fsi_master_hub *hub = to_fsi_master_hub(master);

	if (id != 0)
		return -EINVAL;

	addr += hub->addr + (link * FSI_HUB_LINK_SIZE);
	return fsi_slave_read(hub->upstream->slave, addr, val, size);
}

static int hub_master_write(struct fsi_master *master, int link,
			uint8_t id, uint32_t addr, const void *val, size_t size)
{
	struct fsi_master_hub *hub = to_fsi_master_hub(master);

	if (id != 0)
		return -EINVAL;

	addr += hub->addr + (link * FSI_HUB_LINK_SIZE);
	return fsi_slave_write(hub->upstream->slave, addr, val, size);
}

static int hub_master_break(struct fsi_master *master, int link)
{
	uint32_t addr;
	__be32 cmd;

	addr = 0x4;
	cmd = cpu_to_be32(0xc0de0000);

	return hub_master_write(master, link, 0, addr, &cmd, sizeof(cmd));
}

static int hub_master_link_enable(struct fsi_master *master, int link)
{
	struct fsi_master_hub *hub = to_fsi_master_hub(master);
	int idx, bit;
	__be32 reg;
	int rc;

	idx = link / 32;
	bit = link % 32;

	reg = cpu_to_be32(0x80000000 >> bit);

	rc = fsi_device_write(hub->upstream, FSI_MSENP0 + (4 * idx), &reg, 4);

	mdelay(FSI_LINK_ENABLE_SETUP_TIME);

	fsi_device_read(hub->upstream, FSI_MENP0 + (4 * idx), &reg, 4);

	return rc;
}

static void hub_master_release(struct device *dev)
{
	struct fsi_master_hub *hub = to_fsi_master_hub(dev_to_fsi_master(dev));

	kfree(hub);
}

/* mmode encoders */
static inline u32 fsi_mmode_crs0(u32 x)
{
	return (x & FSI_MMODE_CRS0MASK) << FSI_MMODE_CRS0SHFT;
}

static inline u32 fsi_mmode_crs1(u32 x)
{
	return (x & FSI_MMODE_CRS1MASK) << FSI_MMODE_CRS1SHFT;
}

static int hub_master_init(struct fsi_master_hub *hub)
{
	struct fsi_device *dev = hub->upstream;
	__be32 reg;
	int rc;

	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK
			| FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE);
	rc = fsi_device_write(dev, FSI_MRESP0, &reg, sizeof(reg));
	if (rc)
		return rc;

	/* Initialize the MFSI (hub master) engine */
	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK
			| FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE);
	rc = fsi_device_write(dev, FSI_MRESP0, &reg, sizeof(reg));
	if (rc)
		return rc;

	reg = cpu_to_be32(FSI_MECTRL_EOAE | FSI_MECTRL_P8_AUTO_TERM);
	rc = fsi_device_write(dev, FSI_MECTRL, &reg, sizeof(reg));
	if (rc)
		return rc;

	reg = cpu_to_be32(FSI_MMODE_EIP | FSI_MMODE_ECRC | FSI_MMODE_EPC
			| fsi_mmode_crs0(1) | fsi_mmode_crs1(1)
			| FSI_MMODE_P8_TO_LSB);
	rc = fsi_device_write(dev, FSI_MMODE, &reg, sizeof(reg));
	if (rc)
		return rc;

	reg = cpu_to_be32(0xffff0000);
	rc = fsi_device_write(dev, FSI_MDLYR, &reg, sizeof(reg));
	if (rc)
		return rc;

	reg = cpu_to_be32(~0);
	rc = fsi_device_write(dev, FSI_MSENP0, &reg, sizeof(reg));
	if (rc)
		return rc;

	/* Leave enabled long enough for master logic to set up */
	mdelay(FSI_LINK_ENABLE_SETUP_TIME);

	rc = fsi_device_write(dev, FSI_MCENP0, &reg, sizeof(reg));
	if (rc)
		return rc;

	rc = fsi_device_read(dev, FSI_MAEB, &reg, sizeof(reg));
	if (rc)
		return rc;

	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK);
	rc = fsi_device_write(dev, FSI_MRESP0, &reg, sizeof(reg));
	if (rc)
		return rc;

	rc = fsi_device_read(dev, FSI_MLEVP0, &reg, sizeof(reg));
	if (rc)
		return rc;

	/* Reset the master bridge */
	reg = cpu_to_be32(FSI_MRESB_RST_GEN);
	rc = fsi_device_write(dev, FSI_MRESB0, &reg, sizeof(reg));
	if (rc)
		return rc;

	reg = cpu_to_be32(FSI_MRESB_RST_ERR);
	return fsi_device_write(dev, FSI_MRESB0, &reg, sizeof(reg));
}

static int hub_master_probe(struct device *dev)
{
	struct fsi_device *fsi_dev = to_fsi_dev(dev);
	struct fsi_master_hub *hub;
	uint32_t reg, links;
	__be32 __reg;
	int rc;

	rc = fsi_device_read(fsi_dev, FSI_MVER, &__reg, sizeof(__reg));
	if (rc)
		return rc;

	reg = be32_to_cpu(__reg);
	links = (reg >> 8) & 0xff;
	dev_dbg(dev, "hub version %08x (%d links)\n", reg, links);

	rc = fsi_slave_claim_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET,
			FSI_HUB_LINK_SIZE * links);
	if (rc) {
		dev_err(dev, "can't claim slave address range for links");
		return rc;
	}

	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
	if (!hub) {
		rc = -ENOMEM;
		goto err_release;
	}

	hub->addr = FSI_HUB_LINK_OFFSET;
	hub->size = FSI_HUB_LINK_SIZE * links;
	hub->upstream = fsi_dev;

	hub->master.dev.parent = dev;
	hub->master.dev.release = hub_master_release;
	hub->master.dev.of_node = of_node_get(dev_of_node(dev));

	hub->master.n_links = links;
	hub->master.read = hub_master_read;
	hub->master.write = hub_master_write;
	hub->master.send_break = hub_master_break;
	hub->master.link_enable = hub_master_link_enable;

	dev_set_drvdata(dev, hub);

	hub_master_init(hub);

	rc = fsi_master_register(&hub->master);
	if (rc)
		goto err_release;

	/* At this point, fsi_master_register performs the device_initialize(),
	 * and holds the sole reference on master.dev. This means the device
	 * will be freed (via ->release) during any subsequent call to
	 * fsi_master_unregister.  We add our own reference to it here, so we
	 * can perform cleanup (in _remove()) without it being freed before
	 * we're ready.
	 */
	get_device(&hub->master.dev);
	return 0;

err_release:
	fsi_slave_release_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET,
			FSI_HUB_LINK_SIZE * links);
	return rc;
}

static int hub_master_remove(struct device *dev)
{
	struct fsi_master_hub *hub = dev_get_drvdata(dev);

	fsi_master_unregister(&hub->master);
	fsi_slave_release_range(hub->upstream->slave, hub->addr, hub->size);
	of_node_put(hub->master.dev.of_node);

	/*
	 * master.dev will likely be ->release()ed after this, which free()s
	 * the hub
	 */
	put_device(&hub->master.dev);

	return 0;
}

static struct fsi_device_id hub_master_ids[] = {
	{
		.engine_type = FSI_ENGID_HUB_MASTER,
		.version = FSI_VERSION_ANY,
	},
	{ 0 }
};

static struct fsi_driver hub_master_driver = {
	.id_table = hub_master_ids,
	.drv = {
		.name = "fsi-master-hub",
		.bus = &fsi_bus_type,
		.probe = hub_master_probe,
		.remove = hub_master_remove,
	}
};

module_fsi_driver(hub_master_driver);
MODULE_LICENSE("GPL");
Commit	Line	Data
1802d0be	1	// SPDX-License-Identifier: GPL-2.0-only
7f9e8f76 CB	2	/*
	3	* FSI hub master driver
	4	*
	5	* Copyright (C) IBM Corporation 2016
7f9e8f76 CB	6	*/
	7
	8	#include <linux/delay.h>
	9	#include <linux/fsi.h>
	10	#include <linux/module.h>
f6a2f8eb	11	#include <linux/of.h>
7f9e8f76 CB	12	#include <linux/slab.h>
	13
	14	#include "fsi-master.h"
	15
7f9e8f76	16	#define FSI_ENGID_HUB_MASTER 0x1c
7f9e8f76 CB	17
	18	#define FSI_LINK_ENABLE_SETUP_TIME 10 /* in mS */
	19
	20	/*
	21	* FSI hub master support
	22	*
	23	* A hub master increases the number of potential target devices that the
	24	* primary FSI master can access. For each link a primary master supports,
	25	* each of those links can in turn be chained to a hub master with multiple
	26	* links of its own.
	27	*
	28	* The hub is controlled by a set of control registers exposed as a regular fsi
	29	* device (the hub->upstream device), and provides access to the downstream FSI
	30	* bus as through an address range on the slave itself (->addr and ->size).
	31	*
	32	* [This differs from "cascaded" masters, which expose the entire downstream
	33	* bus entirely through the fsi device address range, and so have a smaller
	34	* accessible address space.]
	35	*/
	36	struct fsi_master_hub {
	37	struct fsi_master master;
	38	struct fsi_device *upstream;
	39	uint32_t addr, size; /* slave-relative addr of */
	40	/* master address space */
	41	};
	42
	43	#define to_fsi_master_hub(m) container_of(m, struct fsi_master_hub, master)
	44
	45	static int hub_master_read(struct fsi_master *master, int link,
	46	uint8_t id, uint32_t addr, void *val, size_t size)
	47	{
	48	struct fsi_master_hub *hub = to_fsi_master_hub(master);
	49
	50	if (id != 0)
	51	return -EINVAL;
	52
	53	addr += hub->addr + (link * FSI_HUB_LINK_SIZE);
	54	return fsi_slave_read(hub->upstream->slave, addr, val, size);
	55	}
	56
	57	static int hub_master_write(struct fsi_master *master, int link,
	58	uint8_t id, uint32_t addr, const void *val, size_t size)
	59	{
	60	struct fsi_master_hub *hub = to_fsi_master_hub(master);
	61
	62	if (id != 0)
	63	return -EINVAL;
	64
	65	addr += hub->addr + (link * FSI_HUB_LINK_SIZE);
	66	return fsi_slave_write(hub->upstream->slave, addr, val, size);
	67	}
	68
	69	static int hub_master_break(struct fsi_master *master, int link)
	70	{
fbdb5eac JS	71	uint32_t addr;
fbdb5eac JS	72	__be32 cmd;
7f9e8f76 CB	73
	74	addr = 0x4;
	75	cmd = cpu_to_be32(0xc0de0000);
	76
	77	return hub_master_write(master, link, 0, addr, &cmd, sizeof(cmd));
	78	}
	79
	80	static int hub_master_link_enable(struct fsi_master *master, int link)
	81	{
	82	struct fsi_master_hub *hub = to_fsi_master_hub(master);
	83	int idx, bit;
	84	__be32 reg;
	85	int rc;
	86
	87	idx = link / 32;
	88	bit = link % 32;
	89
	90	reg = cpu_to_be32(0x80000000 >> bit);
	91
	92	rc = fsi_device_write(hub->upstream, FSI_MSENP0 + (4 * idx), &reg, 4);
	93
	94	mdelay(FSI_LINK_ENABLE_SETUP_TIME);
	95
	96	fsi_device_read(hub->upstream, FSI_MENP0 + (4 * idx), &reg, 4);
	97
	98	return rc;
	99	}
	100
	101	static void hub_master_release(struct device *dev)
	102	{
	103	struct fsi_master_hub *hub = to_fsi_master_hub(dev_to_fsi_master(dev));
	104
	105	kfree(hub);
	106	}
	107
	108	/* mmode encoders */
	109	static inline u32 fsi_mmode_crs0(u32 x)
	110	{
	111	return (x & FSI_MMODE_CRS0MASK) << FSI_MMODE_CRS0SHFT;
	112	}
	113
	114	static inline u32 fsi_mmode_crs1(u32 x)
	115	{
	116	return (x & FSI_MMODE_CRS1MASK) << FSI_MMODE_CRS1SHFT;
	117	}
	118
	119	static int hub_master_init(struct fsi_master_hub *hub)
	120	{
	121	struct fsi_device *dev = hub->upstream;
	122	__be32 reg;
	123	int rc;
	124
	125	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER \| FSI_MRESP_RST_ALL_LINK
	126	\| FSI_MRESP_RST_MCR \| FSI_MRESP_RST_PYE);
	127	rc = fsi_device_write(dev, FSI_MRESP0, &reg, sizeof(reg));
	128	if (rc)
	129	return rc;
	130
	131	/* Initialize the MFSI (hub master) engine */
	132	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER \| FSI_MRESP_RST_ALL_LINK
	133	\| FSI_MRESP_RST_MCR \| FSI_MRESP_RST_PYE);
	134	rc = fsi_device_write(dev, FSI_MRESP0, &reg, sizeof(reg));
	135	if (rc)
	136	return rc;
137
138	reg = cpu_to_be32(FSI_MECTRL_EOAE \| FSI_MECTRL_P8_AUTO_TERM);
139	rc = fsi_device_write(dev, FSI_MECTRL, &reg, sizeof(reg));
140	if (rc)
141	return rc;
142
143	reg = cpu_to_be32(FSI_MMODE_EIP \| FSI_MMODE_ECRC \| FSI_MMODE_EPC
144	\| fsi_mmode_crs0(1) \| fsi_mmode_crs1(1)
145	\| FSI_MMODE_P8_TO_LSB);
146	rc = fsi_device_write(dev, FSI_MMODE, &reg, sizeof(reg));
147	if (rc)
148	return rc;
149
150	reg = cpu_to_be32(0xffff0000);
151	rc = fsi_device_write(dev, FSI_MDLYR, &reg, sizeof(reg));
152	if (rc)
153	return rc;
154
fbdb5eac	155	reg = cpu_to_be32(~0);
7f9e8f76 CB	156	rc = fsi_device_write(dev, FSI_MSENP0, &reg, sizeof(reg));
	157	if (rc)
	158	return rc;
	159
	160	/* Leave enabled long enough for master logic to set up */
	161	mdelay(FSI_LINK_ENABLE_SETUP_TIME);
	162
	163	rc = fsi_device_write(dev, FSI_MCENP0, &reg, sizeof(reg));
	164	if (rc)
	165	return rc;
	166
	167	rc = fsi_device_read(dev, FSI_MAEB, &reg, sizeof(reg));
	168	if (rc)
	169	return rc;
	170
	171	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER \| FSI_MRESP_RST_ALL_LINK);
	172	rc = fsi_device_write(dev, FSI_MRESP0, &reg, sizeof(reg));
	173	if (rc)
	174	return rc;
	175
	176	rc = fsi_device_read(dev, FSI_MLEVP0, &reg, sizeof(reg));
	177	if (rc)
	178	return rc;
	179
	180	/* Reset the master bridge */
	181	reg = cpu_to_be32(FSI_MRESB_RST_GEN);
	182	rc = fsi_device_write(dev, FSI_MRESB0, &reg, sizeof(reg));
	183	if (rc)
	184	return rc;
	185
	186	reg = cpu_to_be32(FSI_MRESB_RST_ERR);
	187	return fsi_device_write(dev, FSI_MRESB0, &reg, sizeof(reg));
	188	}
	189
	190	static int hub_master_probe(struct device *dev)
	191	{
	192	struct fsi_device *fsi_dev = to_fsi_dev(dev);
	193	struct fsi_master_hub *hub;
	194	uint32_t reg, links;
	195	__be32 __reg;
	196	int rc;
	197
	198	rc = fsi_device_read(fsi_dev, FSI_MVER, &__reg, sizeof(__reg));
	199	if (rc)
	200	return rc;
	201
	202	reg = be32_to_cpu(__reg);
	203	links = (reg >> 8) & 0xff;
638bd9ac	204	dev_dbg(dev, "hub version %08x (%d links)\n", reg, links);
7f9e8f76 CB	205
	206	rc = fsi_slave_claim_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET,
	207	FSI_HUB_LINK_SIZE * links);
	208	if (rc) {
	209	dev_err(dev, "can't claim slave address range for links");
	210	return rc;
	211	}
	212
	213	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
	214	if (!hub) {
	215	rc = -ENOMEM;
	216	goto err_release;
	217	}
	218
	219	hub->addr = FSI_HUB_LINK_OFFSET;
	220	hub->size = FSI_HUB_LINK_SIZE * links;
	221	hub->upstream = fsi_dev;
	222
	223	hub->master.dev.parent = dev;
	224	hub->master.dev.release = hub_master_release;
f6a2f8eb	225	hub->master.dev.of_node = of_node_get(dev_of_node(dev));
7f9e8f76 CB	226
	227	hub->master.n_links = links;
	228	hub->master.read = hub_master_read;
	229	hub->master.write = hub_master_write;
	230	hub->master.send_break = hub_master_break;
	231	hub->master.link_enable = hub_master_link_enable;
	232
	233	dev_set_drvdata(dev, hub);
	234
	235	hub_master_init(hub);
	236
	237	rc = fsi_master_register(&hub->master);
e0c24bdd JK	238	if (rc)
	239	goto err_release;
	240
	241	/* At this point, fsi_master_register performs the device_initialize(),
	242	* and holds the sole reference on master.dev. This means the device
	243	* will be freed (via ->release) during any subsequent call to
	244	* fsi_master_unregister. We add our own reference to it here, so we
	245	* can perform cleanup (in _remove()) without it being freed before
	246	* we're ready.
	247	*/
	248	get_device(&hub->master.dev);
	249	return 0;
7f9e8f76	250
7f9e8f76 CB	251	err_release:
	252	fsi_slave_release_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET,
	253	FSI_HUB_LINK_SIZE * links);
	254	return rc;
	255	}
	256
	257	static int hub_master_remove(struct device *dev)
	258	{
	259	struct fsi_master_hub *hub = dev_get_drvdata(dev);
	260
	261	fsi_master_unregister(&hub->master);
	262	fsi_slave_release_range(hub->upstream->slave, hub->addr, hub->size);
f6a2f8eb JK	263	of_node_put(hub->master.dev.of_node);
f6a2f8eb JK	264
e0c24bdd JK	265	/*
	266	* master.dev will likely be ->release()ed after this, which free()s
	267	* the hub
	268	*/
	269	put_device(&hub->master.dev);
	270
7f9e8f76 CB	271	return 0;
	272	}
	273
	274	static struct fsi_device_id hub_master_ids[] = {
	275	{
	276	.engine_type = FSI_ENGID_HUB_MASTER,
	277	.version = FSI_VERSION_ANY,
	278	},
	279	{ 0 }
	280	};
	281
	282	static struct fsi_driver hub_master_driver = {
	283	.id_table = hub_master_ids,
	284	.drv = {
	285	.name = "fsi-master-hub",
	286	.bus = &fsi_bus_type,
	287	.probe = hub_master_probe,
	288	.remove = hub_master_remove,
	289	}
	290	};
	291
	292	module_fsi_driver(hub_master_driver);
	293	MODULE_LICENSE("GPL");