[mirror_ubuntu-bionic-kernel.git] / drivers / fsi / fsi-core.c

/*
 * FSI core driver
 *
 * Copyright (C) IBM Corporation 2016
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/crc4.h>
#include <linux/device.h>
#include <linux/fsi.h>
#include <linux/idr.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/bitops.h>

#include "fsi-master.h"

#define FSI_SLAVE_CONF_NEXT_MASK	GENMASK(31, 31)
#define FSI_SLAVE_CONF_SLOTS_MASK	GENMASK(23, 16)
#define FSI_SLAVE_CONF_SLOTS_SHIFT	16
#define FSI_SLAVE_CONF_VERSION_MASK	GENMASK(15, 12)
#define FSI_SLAVE_CONF_VERSION_SHIFT	12
#define FSI_SLAVE_CONF_TYPE_MASK	GENMASK(11, 4)
#define FSI_SLAVE_CONF_TYPE_SHIFT	4
#define FSI_SLAVE_CONF_CRC_SHIFT	4
#define FSI_SLAVE_CONF_CRC_MASK		GENMASK(3, 0)
#define FSI_SLAVE_CONF_DATA_BITS	28

#define FSI_PEEK_BASE			0x410

static const int engine_page_size = 0x400;

#define FSI_SLAVE_BASE			0x800

/*
 * FSI slave engine control register offsets
 */
#define FSI_SMODE			0x0	/* R/W: Mode register */

/*
 * SMODE fields
 */
#define FSI_SMODE_WSC		0x80000000	/* Warm start done */
#define FSI_SMODE_ECRC		0x20000000	/* Hw CRC check */
#define FSI_SMODE_SID_SHIFT	24		/* ID shift */
#define FSI_SMODE_SID_MASK	3		/* ID Mask */
#define FSI_SMODE_ED_SHIFT	20		/* Echo delay shift */
#define FSI_SMODE_ED_MASK	0xf		/* Echo delay mask */
#define FSI_SMODE_SD_SHIFT	16		/* Send delay shift */
#define FSI_SMODE_SD_MASK	0xf		/* Send delay mask */
#define FSI_SMODE_LBCRR_SHIFT	8		/* Clk ratio shift */
#define FSI_SMODE_LBCRR_MASK	0xf		/* Clk ratio mask */

#define FSI_SLAVE_SIZE_23b		0x800000

static DEFINE_IDA(master_ida);

struct fsi_slave {
	struct device		dev;
	struct fsi_master	*master;
	int			id;
	int			link;
	uint32_t		size;	/* size of slave address space */
};

#define to_fsi_master(d) container_of(d, struct fsi_master, dev)
#define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)

static int fsi_master_read(struct fsi_master *master, int link,
		uint8_t slave_id, uint32_t addr, void *val, size_t size);
static int fsi_master_write(struct fsi_master *master, int link,
		uint8_t slave_id, uint32_t addr, const void *val, size_t size);
static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
		void *val, size_t size);
static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
		const void *val, size_t size);

/*
 * fsi_device_read() / fsi_device_write() / fsi_device_peek()
 *
 * FSI endpoint-device support
 *
 * Read / write / peek accessors for a client
 *
 * Parameters:
 * dev:  Structure passed to FSI client device drivers on probe().
 * addr: FSI address of given device.  Client should pass in its base address
 *       plus desired offset to access its register space.
 * val:  For read/peek this is the value read at the specified address. For
 *       write this is value to write to the specified address.
 *       The data in val must be FSI bus endian (big endian).
 * size: Size in bytes of the operation.  Sizes supported are 1, 2 and 4 bytes.
 *       Addresses must be aligned on size boundaries or an error will result.
 */
int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val,
		size_t size)
{
	if (addr > dev->size || size > dev->size || addr > dev->size - size)
		return -EINVAL;

	return fsi_slave_read(dev->slave, dev->addr + addr, val, size);
}
EXPORT_SYMBOL_GPL(fsi_device_read);

int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val,
		size_t size)
{
	if (addr > dev->size || size > dev->size || addr > dev->size - size)
		return -EINVAL;

	return fsi_slave_write(dev->slave, dev->addr + addr, val, size);
}
EXPORT_SYMBOL_GPL(fsi_device_write);

int fsi_device_peek(struct fsi_device *dev, void *val)
{
	uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t));

	return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t));
}

static void fsi_device_release(struct device *_device)
{
	struct fsi_device *device = to_fsi_dev(_device);

	kfree(device);
}

static struct fsi_device *fsi_create_device(struct fsi_slave *slave)
{
	struct fsi_device *dev;

	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev)
		return NULL;

	dev->dev.parent = &slave->dev;
	dev->dev.bus = &fsi_bus_type;
	dev->dev.release = fsi_device_release;

	return dev;
}

/* FSI slave support */
static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp,
		uint8_t *idp)
{
	uint32_t addr = *addrp;
	uint8_t id = *idp;

	if (addr > slave->size)
		return -EINVAL;

	/* For 23 bit addressing, we encode the extra two bits in the slave
	 * id (and the slave's actual ID needs to be 0).
	 */
	if (addr > 0x1fffff) {
		if (slave->id != 0)
			return -EINVAL;
		id = (addr >> 21) & 0x3;
		addr &= 0x1fffff;
	}

	*addrp = addr;
	*idp = id;
	return 0;
}

static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
			void *val, size_t size)
{
	uint8_t id = slave->id;
	int rc;

	rc = fsi_slave_calc_addr(slave, &addr, &id);
	if (rc)
		return rc;

	return fsi_master_read(slave->master, slave->link, id,
			addr, val, size);
}

static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
			const void *val, size_t size)
{
	uint8_t id = slave->id;
	int rc;

	rc = fsi_slave_calc_addr(slave, &addr, &id);
	if (rc)
		return rc;

	return fsi_master_write(slave->master, slave->link, id,
			addr, val, size);
}

static int fsi_slave_scan(struct fsi_slave *slave)
{
	uint32_t engine_addr;
	uint32_t conf;
	int rc, i;

	/*
	 * scan engines
	 *
	 * We keep the peek mode and slave engines for the core; so start
	 * at the third slot in the configuration table. We also need to
	 * skip the chip ID entry at the start of the address space.
	 */
	engine_addr = engine_page_size * 3;
	for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) {
		uint8_t slots, version, type, crc;
		struct fsi_device *dev;

		rc = fsi_slave_read(slave, (i + 1) * sizeof(conf),
				&conf, sizeof(conf));
		if (rc) {
			dev_warn(&slave->dev,
				"error reading slave registers\n");
			return -1;
		}
		conf = be32_to_cpu(conf);

		crc = crc4(0, conf, 32);
		if (crc) {
			dev_warn(&slave->dev,
				"crc error in slave register at 0x%04x\n",
				i);
			return -1;
		}

		slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK)
			>> FSI_SLAVE_CONF_SLOTS_SHIFT;
		version = (conf & FSI_SLAVE_CONF_VERSION_MASK)
			>> FSI_SLAVE_CONF_VERSION_SHIFT;
		type = (conf & FSI_SLAVE_CONF_TYPE_MASK)
			>> FSI_SLAVE_CONF_TYPE_SHIFT;

		/*
		 * Unused address areas are marked by a zero type value; this
		 * skips the defined address areas
		 */
		if (type != 0 && slots != 0) {

			/* create device */
			dev = fsi_create_device(slave);
			if (!dev)
				return -ENOMEM;

			dev->slave = slave;
			dev->engine_type = type;
			dev->version = version;
			dev->unit = i;
			dev->addr = engine_addr;
			dev->size = slots * engine_page_size;

			dev_dbg(&slave->dev,
			"engine[%i]: type %x, version %x, addr %x size %x\n",
					dev->unit, dev->engine_type, version,
					dev->addr, dev->size);

			dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x",
					slave->master->idx, slave->link,
					slave->id, i - 2);

			rc = device_register(&dev->dev);
			if (rc) {
				dev_warn(&slave->dev, "add failed: %d\n", rc);
				put_device(&dev->dev);
			}
		}

		engine_addr += slots * engine_page_size;

		if (!(conf & FSI_SLAVE_CONF_NEXT_MASK))
			break;
	}

	return 0;
}

static ssize_t fsi_slave_sysfs_raw_read(struct file *file,
		struct kobject *kobj, struct bin_attribute *attr, char *buf,
		loff_t off, size_t count)
{
	struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
	size_t total_len, read_len;
	int rc;

	if (off < 0)
		return -EINVAL;

	if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
		return -EINVAL;

	for (total_len = 0; total_len < count; total_len += read_len) {
		read_len = min_t(size_t, count, 4);
		read_len -= off & 0x3;

		rc = fsi_slave_read(slave, off, buf + total_len, read_len);
		if (rc)
			return rc;

		off += read_len;
	}

	return count;
}

static ssize_t fsi_slave_sysfs_raw_write(struct file *file,
		struct kobject *kobj, struct bin_attribute *attr,
		char *buf, loff_t off, size_t count)
{
	struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
	size_t total_len, write_len;
	int rc;

	if (off < 0)
		return -EINVAL;

	if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
		return -EINVAL;

	for (total_len = 0; total_len < count; total_len += write_len) {
		write_len = min_t(size_t, count, 4);
		write_len -= off & 0x3;

		rc = fsi_slave_write(slave, off, buf + total_len, write_len);
		if (rc)
			return rc;

		off += write_len;
	}

	return count;
}

static struct bin_attribute fsi_slave_raw_attr = {
	.attr = {
		.name = "raw",
		.mode = 0600,
	},
	.size = 0,
	.read = fsi_slave_sysfs_raw_read,
	.write = fsi_slave_sysfs_raw_write,
};

static ssize_t fsi_slave_sysfs_term_write(struct file *file,
		struct kobject *kobj, struct bin_attribute *attr,
		char *buf, loff_t off, size_t count)
{
	struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
	struct fsi_master *master = slave->master;

	if (!master->term)
		return -ENODEV;

	master->term(master, slave->link, slave->id);
	return count;
}

static struct bin_attribute fsi_slave_term_attr = {
	.attr = {
		.name = "term",
		.mode = 0200,
	},
	.size = 0,
	.write = fsi_slave_sysfs_term_write,
};

/* Encode slave local bus echo delay */
static inline uint32_t fsi_smode_echodly(int x)
{
	return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT;
}

/* Encode slave local bus send delay */
static inline uint32_t fsi_smode_senddly(int x)
{
	return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT;
}

/* Encode slave local bus clock rate ratio */
static inline uint32_t fsi_smode_lbcrr(int x)
{
	return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT;
}

/* Encode slave ID */
static inline uint32_t fsi_smode_sid(int x)
{
	return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT;
}

static const uint32_t fsi_slave_smode(int id)
{
	return FSI_SMODE_WSC | FSI_SMODE_ECRC
		| fsi_smode_sid(id)
		| fsi_smode_echodly(0xf) | fsi_smode_senddly(0xf)
		| fsi_smode_lbcrr(0x8);
}

static int fsi_slave_set_smode(struct fsi_master *master, int link, int id)
{
	uint32_t smode;

	/* set our smode register with the slave ID field to 0; this enables
	 * extended slave addressing
	 */
	smode = fsi_slave_smode(id);
	smode = cpu_to_be32(smode);

	return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SMODE,
			&smode, sizeof(smode));
}

static void fsi_slave_release(struct device *dev)
{
	struct fsi_slave *slave = to_fsi_slave(dev);

	kfree(slave);
}

static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
{
	struct fsi_slave *slave;
	uint32_t chip_id;
	uint8_t crc;
	int rc;

	/* Currently, we only support single slaves on a link, and use the
	 * full 23-bit address range
	 */
	if (id != 0)
		return -EINVAL;

	rc = fsi_master_read(master, link, id, 0, &chip_id, sizeof(chip_id));
	if (rc) {
		dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n",
				link, id, rc);
		return -ENODEV;
	}
	chip_id = be32_to_cpu(chip_id);

	crc = crc4(0, chip_id, 32);
	if (crc) {
		dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n",
				link, id);
		return -EIO;
	}

	dev_info(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
			chip_id, master->idx, link, id);

	rc = fsi_slave_set_smode(master, link, id);
	if (rc) {
		dev_warn(&master->dev,
				"can't set smode on slave:%02x:%02x %d\n",
				link, id, rc);
		return -ENODEV;
	}

	/* We can communicate with a slave; create the slave device and
	 * register.
	 */
	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
	if (!slave)
		return -ENOMEM;

	slave->master = master;
	slave->dev.parent = &master->dev;
	slave->dev.release = fsi_slave_release;
	slave->link = link;
	slave->id = id;
	slave->size = FSI_SLAVE_SIZE_23b;

	dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);
	rc = device_register(&slave->dev);
	if (rc < 0) {
		dev_warn(&master->dev, "failed to create slave device: %d\n",
				rc);
		put_device(&slave->dev);
		return rc;
	}

	rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr);
	if (rc)
		dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc);

	rc = device_create_bin_file(&slave->dev, &fsi_slave_term_attr);
	if (rc)
		dev_warn(&slave->dev, "failed to create term attr: %d\n", rc);

	rc = fsi_slave_scan(slave);
	if (rc)
		dev_dbg(&master->dev, "failed during slave scan with: %d\n",
				rc);

	return rc;
}

/* FSI master support */
static int fsi_check_access(uint32_t addr, size_t size)
{
	if (size != 1 && size != 2 && size != 4)
		return -EINVAL;

	if ((addr & 0x3) != (size & 0x3))
		return -EINVAL;

	return 0;
}

static int fsi_master_read(struct fsi_master *master, int link,
		uint8_t slave_id, uint32_t addr, void *val, size_t size)
{
	int rc;

	rc = fsi_check_access(addr, size);
	if (rc)
		return rc;

	return master->read(master, link, slave_id, addr, val, size);
}

static int fsi_master_write(struct fsi_master *master, int link,
		uint8_t slave_id, uint32_t addr, const void *val, size_t size)
{
	int rc;

	rc = fsi_check_access(addr, size);
	if (rc)
		return rc;

	return master->write(master, link, slave_id, addr, val, size);
}

static int fsi_master_link_enable(struct fsi_master *master, int link)
{
	if (master->link_enable)
		return master->link_enable(master, link);

	return 0;
}

/*
 * Issue a break command on this link
 */
static int fsi_master_break(struct fsi_master *master, int link)
{
	if (master->send_break)
		return master->send_break(master, link);

	return 0;
}

static int fsi_master_scan(struct fsi_master *master)
{
	int link, rc;

	for (link = 0; link < master->n_links; link++) {
		rc = fsi_master_link_enable(master, link);
		if (rc) {
			dev_dbg(&master->dev,
				"enable link %d failed: %d\n", link, rc);
			continue;
		}
		rc = fsi_master_break(master, link);
		if (rc) {
			dev_dbg(&master->dev,
				"break to link %d failed: %d\n", link, rc);
			continue;
		}

		fsi_slave_init(master, link, 0);
	}

	return 0;
}

static int fsi_slave_remove_device(struct device *dev, void *arg)
{
	device_unregister(dev);
	return 0;
}

static int fsi_master_remove_slave(struct device *dev, void *arg)
{
	device_for_each_child(dev, NULL, fsi_slave_remove_device);
	device_unregister(dev);
	return 0;
}

static void fsi_master_unscan(struct fsi_master *master)
{
	device_for_each_child(&master->dev, NULL, fsi_master_remove_slave);
}

static ssize_t master_rescan_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct fsi_master *master = to_fsi_master(dev);
	int rc;

	fsi_master_unscan(master);
	rc = fsi_master_scan(master);
	if (rc < 0)
		return rc;

	return count;
}

static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store);

static ssize_t master_break_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct fsi_master *master = to_fsi_master(dev);

	fsi_master_break(master, 0);

	return count;
}

static DEVICE_ATTR(break, 0200, NULL, master_break_store);

int fsi_master_register(struct fsi_master *master)
{
	int rc;

	if (!master)
		return -EINVAL;

	master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);
	dev_set_name(&master->dev, "fsi%d", master->idx);

	rc = device_register(&master->dev);
	if (rc) {
		ida_simple_remove(&master_ida, master->idx);
		return rc;
	}

	rc = device_create_file(&master->dev, &dev_attr_rescan);
	if (rc) {
		device_unregister(&master->dev);
		ida_simple_remove(&master_ida, master->idx);
		return rc;
	}

	rc = device_create_file(&master->dev, &dev_attr_break);
	if (rc) {
		device_unregister(&master->dev);
		ida_simple_remove(&master_ida, master->idx);
		return rc;
	}

	fsi_master_scan(master);

	return 0;
}
EXPORT_SYMBOL_GPL(fsi_master_register);

void fsi_master_unregister(struct fsi_master *master)
{
	if (master->idx >= 0) {
		ida_simple_remove(&master_ida, master->idx);
		master->idx = -1;
	}

	fsi_master_unscan(master);
	device_unregister(&master->dev);
}
EXPORT_SYMBOL_GPL(fsi_master_unregister);

/* FSI core & Linux bus type definitions */

static int fsi_bus_match(struct device *dev, struct device_driver *drv)
{
	struct fsi_device *fsi_dev = to_fsi_dev(dev);
	struct fsi_driver *fsi_drv = to_fsi_drv(drv);
	const struct fsi_device_id *id;

	if (!fsi_drv->id_table)
		return 0;

	for (id = fsi_drv->id_table; id->engine_type; id++) {
		if (id->engine_type != fsi_dev->engine_type)
			continue;
		if (id->version == FSI_VERSION_ANY ||
				id->version == fsi_dev->version)
			return 1;
	}

	return 0;
}

int fsi_driver_register(struct fsi_driver *fsi_drv)
{
	if (!fsi_drv)
		return -EINVAL;
	if (!fsi_drv->id_table)
		return -EINVAL;

	return driver_register(&fsi_drv->drv);
}
EXPORT_SYMBOL_GPL(fsi_driver_register);

void fsi_driver_unregister(struct fsi_driver *fsi_drv)
{
	driver_unregister(&fsi_drv->drv);
}
EXPORT_SYMBOL_GPL(fsi_driver_unregister);

struct bus_type fsi_bus_type = {
	.name		= "fsi",
	.match		= fsi_bus_match,
};
EXPORT_SYMBOL_GPL(fsi_bus_type);

static int fsi_init(void)
{
	return bus_register(&fsi_bus_type);
}

static void fsi_exit(void)
{
	bus_unregister(&fsi_bus_type);
}

module_init(fsi_init);
module_exit(fsi_exit);
Commit	Line	Data
0508ad1f JK	1	/*
	2	* FSI core driver
	3	*
	4	* Copyright (C) IBM Corporation 2016
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*/
	15
2b545cd8	16	#include <linux/crc4.h>
0508ad1f JK	17	#include <linux/device.h>
0508ad1f JK	18	#include <linux/fsi.h>
09aecfab	19	#include <linux/idr.h>
0508ad1f	20	#include <linux/module.h>
2b545cd8	21	#include <linux/slab.h>
f7ade2a6	22	#include <linux/bitops.h>
0508ad1f	23
09aecfab JK	24	#include "fsi-master.h"
09aecfab JK	25
f7ade2a6 JK	26	#define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31)
	27	#define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16)
	28	#define FSI_SLAVE_CONF_SLOTS_SHIFT 16
	29	#define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12)
	30	#define FSI_SLAVE_CONF_VERSION_SHIFT 12
	31	#define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4)
	32	#define FSI_SLAVE_CONF_TYPE_SHIFT 4
	33	#define FSI_SLAVE_CONF_CRC_SHIFT 4
	34	#define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0)
	35	#define FSI_SLAVE_CONF_DATA_BITS 28
	36
4efe37f4 JK	37	#define FSI_PEEK_BASE 0x410
4efe37f4 JK	38
f7ade2a6 JK	39	static const int engine_page_size = 0x400;
f7ade2a6 JK	40
2b37c3e2 CB	41	#define FSI_SLAVE_BASE 0x800
	42
	43	/*
	44	* FSI slave engine control register offsets
	45	*/
	46	#define FSI_SMODE 0x0 /* R/W: Mode register */
	47
	48	/*
	49	* SMODE fields
	50	*/
	51	#define FSI_SMODE_WSC 0x80000000 /* Warm start done */
	52	#define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */
	53	#define FSI_SMODE_SID_SHIFT 24 /* ID shift */
	54	#define FSI_SMODE_SID_MASK 3 /* ID Mask */
	55	#define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */
	56	#define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */
	57	#define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */
	58	#define FSI_SMODE_SD_MASK 0xf /* Send delay mask */
	59	#define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */
	60	#define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */
	61
2b545cd8 JK	62	#define FSI_SLAVE_SIZE_23b 0x800000
2b545cd8 JK	63
09aecfab JK	64	static DEFINE_IDA(master_ida);
09aecfab JK	65
faf0b116 JK	66	struct fsi_slave {
	67	struct device dev;
	68	struct fsi_master *master;
	69	int id;
	70	int link;
	71	uint32_t size; /* size of slave address space */
	72	};
	73
cd0fdb5c	74	#define to_fsi_master(d) container_of(d, struct fsi_master, dev)
faf0b116 JK	75	#define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
faf0b116 JK	76
014c2abc JK	77	static int fsi_master_read(struct fsi_master *master, int link,
	78	uint8_t slave_id, uint32_t addr, void *val, size_t size);
	79	static int fsi_master_write(struct fsi_master *master, int link,
	80	uint8_t slave_id, uint32_t addr, const void *val, size_t size);
4efe37f4 JK	81	static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
	82	void *val, size_t size);
	83	static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
	84	const void *val, size_t size);
	85
	86	/*
	87	* fsi_device_read() / fsi_device_write() / fsi_device_peek()
	88	*
	89	* FSI endpoint-device support
	90	*
	91	* Read / write / peek accessors for a client
	92	*
	93	* Parameters:
	94	* dev: Structure passed to FSI client device drivers on probe().
	95	* addr: FSI address of given device. Client should pass in its base address
	96	* plus desired offset to access its register space.
	97	* val: For read/peek this is the value read at the specified address. For
	98	* write this is value to write to the specified address.
	99	* The data in val must be FSI bus endian (big endian).
	100	* size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes.
	101	* Addresses must be aligned on size boundaries or an error will result.
	102	*/
	103	int fsi_device_read(struct fsi_device dev, uint32_t addr, void val,
	104	size_t size)
	105	{
	106	if (addr > dev->size \|\| size > dev->size \|\| addr > dev->size - size)
	107	return -EINVAL;
	108
	109	return fsi_slave_read(dev->slave, dev->addr + addr, val, size);
	110	}
	111	EXPORT_SYMBOL_GPL(fsi_device_read);
	112
	113	int fsi_device_write(struct fsi_device dev, uint32_t addr, const void val,
	114	size_t size)
	115	{
	116	if (addr > dev->size \|\| size > dev->size \|\| addr > dev->size - size)
	117	return -EINVAL;
	118
	119	return fsi_slave_write(dev->slave, dev->addr + addr, val, size);
	120	}
	121	EXPORT_SYMBOL_GPL(fsi_device_write);
	122
	123	int fsi_device_peek(struct fsi_device dev, void val)
	124	{
	125	uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t));
014c2abc	126
4efe37f4 JK	127	return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t));
4efe37f4 JK	128	}
f7ade2a6 JK	129
	130	static void fsi_device_release(struct device *_device)
	131	{
	132	struct fsi_device *device = to_fsi_dev(_device);
	133
	134	kfree(device);
	135	}
	136
	137	static struct fsi_device fsi_create_device(struct fsi_slave slave)
	138	{
	139	struct fsi_device *dev;
	140
	141	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	142	if (!dev)
	143	return NULL;
	144
	145	dev->dev.parent = &slave->dev;
	146	dev->dev.bus = &fsi_bus_type;
	147	dev->dev.release = fsi_device_release;
	148
	149	return dev;
	150	}
	151
414c1026	152	/* FSI slave support */
014c2abc JK	153	static int fsi_slave_calc_addr(struct fsi_slave slave, uint32_t addrp,
	154	uint8_t *idp)
	155	{
	156	uint32_t addr = *addrp;
	157	uint8_t id = *idp;
	158
	159	if (addr > slave->size)
	160	return -EINVAL;
	161
	162	/* For 23 bit addressing, we encode the extra two bits in the slave
	163	* id (and the slave's actual ID needs to be 0).
	164	*/
	165	if (addr > 0x1fffff) {
	166	if (slave->id != 0)
	167	return -EINVAL;
	168	id = (addr >> 21) & 0x3;
	169	addr &= 0x1fffff;
	170	}
	171
	172	*addrp = addr;
	173	*idp = id;
	174	return 0;
	175	}
	176
	177	static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
	178	void *val, size_t size)
	179	{
	180	uint8_t id = slave->id;
	181	int rc;
	182
	183	rc = fsi_slave_calc_addr(slave, &addr, &id);
	184	if (rc)
	185	return rc;
	186
	187	return fsi_master_read(slave->master, slave->link, id,
	188	addr, val, size);
	189	}
	190
	191	static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
	192	const void *val, size_t size)
	193	{
	194	uint8_t id = slave->id;
	195	int rc;
	196
	197	rc = fsi_slave_calc_addr(slave, &addr, &id);
	198	if (rc)
	199	return rc;
	200
	201	return fsi_master_write(slave->master, slave->link, id,
	202	addr, val, size);
	203	}
	204
f7ade2a6 JK	205	static int fsi_slave_scan(struct fsi_slave *slave)
	206	{
	207	uint32_t engine_addr;
	208	uint32_t conf;
	209	int rc, i;
	210
	211	/*
	212	* scan engines
	213	*
	214	* We keep the peek mode and slave engines for the core; so start
	215	* at the third slot in the configuration table. We also need to
	216	* skip the chip ID entry at the start of the address space.
	217	*/
	218	engine_addr = engine_page_size * 3;
	219	for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) {
	220	uint8_t slots, version, type, crc;
	221	struct fsi_device *dev;
	222
	223	rc = fsi_slave_read(slave, (i + 1) * sizeof(conf),
	224	&conf, sizeof(conf));
	225	if (rc) {
	226	dev_warn(&slave->dev,
	227	"error reading slave registers\n");
	228	return -1;
	229	}
	230	conf = be32_to_cpu(conf);
	231
	232	crc = crc4(0, conf, 32);
	233	if (crc) {
	234	dev_warn(&slave->dev,
	235	"crc error in slave register at 0x%04x\n",
	236	i);
	237	return -1;
	238	}
	239
	240	slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK)
	241	>> FSI_SLAVE_CONF_SLOTS_SHIFT;
	242	version = (conf & FSI_SLAVE_CONF_VERSION_MASK)
	243	>> FSI_SLAVE_CONF_VERSION_SHIFT;
	244	type = (conf & FSI_SLAVE_CONF_TYPE_MASK)
	245	>> FSI_SLAVE_CONF_TYPE_SHIFT;
	246
	247	/*
	248	* Unused address areas are marked by a zero type value; this
	249	* skips the defined address areas
	250	*/
	251	if (type != 0 && slots != 0) {
	252
	253	/* create device */
	254	dev = fsi_create_device(slave);
	255	if (!dev)
	256	return -ENOMEM;
	257
	258	dev->slave = slave;
	259	dev->engine_type = type;
	260	dev->version = version;
	261	dev->unit = i;
	262	dev->addr = engine_addr;
	263	dev->size = slots * engine_page_size;
	264
	265	dev_dbg(&slave->dev,
	266	"engine[%i]: type %x, version %x, addr %x size %x\n",
	267	dev->unit, dev->engine_type, version,
	268	dev->addr, dev->size);
269
270	dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x",
271	slave->master->idx, slave->link,
272	slave->id, i - 2);
273
274	rc = device_register(&dev->dev);
275	if (rc) {
276	dev_warn(&slave->dev, "add failed: %d\n", rc);
277	put_device(&dev->dev);
278	}
279	}
280
281	engine_addr += slots * engine_page_size;
282
283	if (!(conf & FSI_SLAVE_CONF_NEXT_MASK))
284	break;
285	}
286
287	return 0;
288	}
289
125739cb JK	290	static ssize_t fsi_slave_sysfs_raw_read(struct file *file,
	291	struct kobject kobj, struct bin_attribute attr, char *buf,
	292	loff_t off, size_t count)
	293	{
	294	struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
	295	size_t total_len, read_len;
	296	int rc;
	297
	298	if (off < 0)
	299	return -EINVAL;
	300
	301	if (off > 0xffffffff \|\| count > 0xffffffff \|\| off + count > 0xffffffff)
	302	return -EINVAL;
	303
	304	for (total_len = 0; total_len < count; total_len += read_len) {
	305	read_len = min_t(size_t, count, 4);
	306	read_len -= off & 0x3;
	307
	308	rc = fsi_slave_read(slave, off, buf + total_len, read_len);
	309	if (rc)
	310	return rc;
	311
	312	off += read_len;
	313	}
	314
	315	return count;
	316	}
	317
	318	static ssize_t fsi_slave_sysfs_raw_write(struct file *file,
	319	struct kobject kobj, struct bin_attribute attr,
	320	char *buf, loff_t off, size_t count)
	321	{
	322	struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
	323	size_t total_len, write_len;
	324	int rc;
	325
	326	if (off < 0)
	327	return -EINVAL;
	328
	329	if (off > 0xffffffff \|\| count > 0xffffffff \|\| off + count > 0xffffffff)
	330	return -EINVAL;
	331
	332	for (total_len = 0; total_len < count; total_len += write_len) {
	333	write_len = min_t(size_t, count, 4);
	334	write_len -= off & 0x3;
	335
	336	rc = fsi_slave_write(slave, off, buf + total_len, write_len);
	337	if (rc)
	338	return rc;
	339
	340	off += write_len;
	341	}
	342
	343	return count;
	344	}
	345
	346	static struct bin_attribute fsi_slave_raw_attr = {
	347	.attr = {
	348	.name = "raw",
	349	.mode = 0600,
	350	},
	351	.size = 0,
	352	.read = fsi_slave_sysfs_raw_read,
	353	.write = fsi_slave_sysfs_raw_write,
354	};
355
356	static ssize_t fsi_slave_sysfs_term_write(struct file *file,
357	struct kobject kobj, struct bin_attribute attr,
358	char *buf, loff_t off, size_t count)
359	{
360	struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
361	struct fsi_master *master = slave->master;
362
363	if (!master->term)
364	return -ENODEV;
365
366	master->term(master, slave->link, slave->id);
367	return count;
368	}
369
370	static struct bin_attribute fsi_slave_term_attr = {
371	.attr = {
372	.name = "term",
373	.mode = 0200,
374	},
375	.size = 0,
376	.write = fsi_slave_sysfs_term_write,
377	};
378
2b37c3e2 CB	379	/* Encode slave local bus echo delay */
	380	static inline uint32_t fsi_smode_echodly(int x)
	381	{
	382	return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT;
	383	}
	384
	385	/* Encode slave local bus send delay */
	386	static inline uint32_t fsi_smode_senddly(int x)
	387	{
	388	return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT;
	389	}
	390
	391	/* Encode slave local bus clock rate ratio */
	392	static inline uint32_t fsi_smode_lbcrr(int x)
	393	{
	394	return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT;
	395	}
	396
	397	/* Encode slave ID */
	398	static inline uint32_t fsi_smode_sid(int x)
	399	{
	400	return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT;
	401	}
	402
	403	static const uint32_t fsi_slave_smode(int id)
	404	{
	405	return FSI_SMODE_WSC \| FSI_SMODE_ECRC
	406	\| fsi_smode_sid(id)
	407	\| fsi_smode_echodly(0xf) \| fsi_smode_senddly(0xf)
	408	\| fsi_smode_lbcrr(0x8);
	409	}
	410
	411	static int fsi_slave_set_smode(struct fsi_master *master, int link, int id)
	412	{
	413	uint32_t smode;
	414
	415	/* set our smode register with the slave ID field to 0; this enables
	416	* extended slave addressing
	417	*/
	418	smode = fsi_slave_smode(id);
	419	smode = cpu_to_be32(smode);
	420
	421	return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SMODE,
	422	&smode, sizeof(smode));
	423	}
	424
2b545cd8 JK	425	static void fsi_slave_release(struct device *dev)
	426	{
	427	struct fsi_slave *slave = to_fsi_slave(dev);
	428
	429	kfree(slave);
	430	}
	431
414c1026 JK	432	static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
414c1026 JK	433	{
2b545cd8 JK	434	struct fsi_slave *slave;
	435	uint32_t chip_id;
	436	uint8_t crc;
	437	int rc;
	438
	439	/* Currently, we only support single slaves on a link, and use the
	440	* full 23-bit address range
	441	*/
	442	if (id != 0)
	443	return -EINVAL;
	444
	445	rc = fsi_master_read(master, link, id, 0, &chip_id, sizeof(chip_id));
	446	if (rc) {
	447	dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n",
	448	link, id, rc);
	449	return -ENODEV;
	450	}
	451	chip_id = be32_to_cpu(chip_id);
	452
	453	crc = crc4(0, chip_id, 32);
	454	if (crc) {
	455	dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n",
	456	link, id);
	457	return -EIO;
	458	}
	459
	460	dev_info(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
	461	chip_id, master->idx, link, id);
	462
2b37c3e2 CB	463	rc = fsi_slave_set_smode(master, link, id);
	464	if (rc) {
	465	dev_warn(&master->dev,
	466	"can't set smode on slave:%02x:%02x %d\n",
	467	link, id, rc);
	468	return -ENODEV;
	469	}
	470
2b545cd8 JK	471	/* We can communicate with a slave; create the slave device and
	472	* register.
	473	*/
	474	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
	475	if (!slave)
	476	return -ENOMEM;
	477
	478	slave->master = master;
	479	slave->dev.parent = &master->dev;
	480	slave->dev.release = fsi_slave_release;
	481	slave->link = link;
	482	slave->id = id;
	483	slave->size = FSI_SLAVE_SIZE_23b;
	484
	485	dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);
	486	rc = device_register(&slave->dev);
	487	if (rc < 0) {
	488	dev_warn(&master->dev, "failed to create slave device: %d\n",
	489	rc);
	490	put_device(&slave->dev);
	491	return rc;
	492	}
	493
125739cb JK	494	rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr);
	495	if (rc)
	496	dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc);
	497
	498	rc = device_create_bin_file(&slave->dev, &fsi_slave_term_attr);
	499	if (rc)
	500	dev_warn(&slave->dev, "failed to create term attr: %d\n", rc);
	501
f7ade2a6 JK	502	rc = fsi_slave_scan(slave);
	503	if (rc)
	504	dev_dbg(&master->dev, "failed during slave scan with: %d\n",
	505	rc);
414c1026	506
2b545cd8	507	return rc;
414c1026 JK	508	}
414c1026 JK	509
09aecfab	510	/* FSI master support */
014c2abc JK	511	static int fsi_check_access(uint32_t addr, size_t size)
	512	{
	513	if (size != 1 && size != 2 && size != 4)
	514	return -EINVAL;
	515
	516	if ((addr & 0x3) != (size & 0x3))
	517	return -EINVAL;
	518
	519	return 0;
	520	}
	521
	522	static int fsi_master_read(struct fsi_master *master, int link,
	523	uint8_t slave_id, uint32_t addr, void *val, size_t size)
	524	{
	525	int rc;
	526
	527	rc = fsi_check_access(addr, size);
	528	if (rc)
	529	return rc;
	530
	531	return master->read(master, link, slave_id, addr, val, size);
	532	}
	533
	534	static int fsi_master_write(struct fsi_master *master, int link,
	535	uint8_t slave_id, uint32_t addr, const void *val, size_t size)
	536	{
	537	int rc;
	538
	539	rc = fsi_check_access(addr, size);
	540	if (rc)
	541	return rc;
	542
	543	return master->write(master, link, slave_id, addr, val, size);
	544	}
	545
26095282 CB	546	static int fsi_master_link_enable(struct fsi_master *master, int link)
	547	{
	548	if (master->link_enable)
	549	return master->link_enable(master, link);
	550
	551	return 0;
	552	}
	553
	554	/*
	555	* Issue a break command on this link
	556	*/
	557	static int fsi_master_break(struct fsi_master *master, int link)
	558	{
	559	if (master->send_break)
	560	return master->send_break(master, link);
	561
	562	return 0;
	563	}
	564
414c1026 JK	565	static int fsi_master_scan(struct fsi_master *master)
414c1026 JK	566	{
26095282 CB	567	int link, rc;
	568
	569	for (link = 0; link < master->n_links; link++) {
	570	rc = fsi_master_link_enable(master, link);
	571	if (rc) {
	572	dev_dbg(&master->dev,
	573	"enable link %d failed: %d\n", link, rc);
	574	continue;
	575	}
	576	rc = fsi_master_break(master, link);
	577	if (rc) {
	578	dev_dbg(&master->dev,
	579	"break to link %d failed: %d\n", link, rc);
	580	continue;
	581	}
414c1026	582
414c1026	583	fsi_slave_init(master, link, 0);
26095282	584	}
414c1026 JK	585
	586	return 0;
	587	}
	588
cd0fdb5c CB	589	static int fsi_slave_remove_device(struct device dev, void arg)
	590	{
	591	device_unregister(dev);
	592	return 0;
	593	}
	594
	595	static int fsi_master_remove_slave(struct device dev, void arg)
	596	{
	597	device_for_each_child(dev, NULL, fsi_slave_remove_device);
	598	device_unregister(dev);
	599	return 0;
	600	}
	601
	602	static void fsi_master_unscan(struct fsi_master *master)
	603	{
	604	device_for_each_child(&master->dev, NULL, fsi_master_remove_slave);
	605	}
	606
	607	static ssize_t master_rescan_store(struct device *dev,
	608	struct device_attribute attr, const char buf, size_t count)
	609	{
	610	struct fsi_master *master = to_fsi_master(dev);
	611	int rc;
	612
	613	fsi_master_unscan(master);
	614	rc = fsi_master_scan(master);
	615	if (rc < 0)
	616	return rc;
	617
	618	return count;
	619	}
	620
	621	static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store);
	622
125739cb JK	623	static ssize_t master_break_store(struct device *dev,
	624	struct device_attribute attr, const char buf, size_t count)
	625	{
	626	struct fsi_master *master = to_fsi_master(dev);
	627
	628	fsi_master_break(master, 0);
	629
	630	return count;
	631	}
	632
	633	static DEVICE_ATTR(break, 0200, NULL, master_break_store);
	634
09aecfab JK	635	int fsi_master_register(struct fsi_master *master)
	636	{
	637	int rc;
	638
	639	if (!master)
	640	return -EINVAL;
	641
	642	master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);
	643	dev_set_name(&master->dev, "fsi%d", master->idx);
	644
	645	rc = device_register(&master->dev);
414c1026	646	if (rc) {
09aecfab	647	ida_simple_remove(&master_ida, master->idx);
414c1026 JK	648	return rc;
414c1026 JK	649	}
09aecfab	650
cd0fdb5c CB	651	rc = device_create_file(&master->dev, &dev_attr_rescan);
	652	if (rc) {
	653	device_unregister(&master->dev);
	654	ida_simple_remove(&master_ida, master->idx);
	655	return rc;
	656	}
	657
125739cb JK	658	rc = device_create_file(&master->dev, &dev_attr_break);
	659	if (rc) {
	660	device_unregister(&master->dev);
	661	ida_simple_remove(&master_ida, master->idx);
	662	return rc;
	663	}
	664
414c1026	665	fsi_master_scan(master);
cd0fdb5c	666
414c1026	667	return 0;
09aecfab JK	668	}
	669	EXPORT_SYMBOL_GPL(fsi_master_register);
	670
	671	void fsi_master_unregister(struct fsi_master *master)
	672	{
	673	if (master->idx >= 0) {
	674	ida_simple_remove(&master_ida, master->idx);
	675	master->idx = -1;
	676	}
	677
cd0fdb5c	678	fsi_master_unscan(master);
09aecfab JK	679	device_unregister(&master->dev);
	680	}
	681	EXPORT_SYMBOL_GPL(fsi_master_unregister);
	682
0508ad1f JK	683	/* FSI core & Linux bus type definitions */
0508ad1f JK	684
dd37eed7 JK	685	static int fsi_bus_match(struct device dev, struct device_driver drv)
	686	{
	687	struct fsi_device *fsi_dev = to_fsi_dev(dev);
	688	struct fsi_driver *fsi_drv = to_fsi_drv(drv);
	689	const struct fsi_device_id *id;
	690
	691	if (!fsi_drv->id_table)
	692	return 0;
	693
	694	for (id = fsi_drv->id_table; id->engine_type; id++) {
	695	if (id->engine_type != fsi_dev->engine_type)
	696	continue;
	697	if (id->version == FSI_VERSION_ANY \|\|
	698	id->version == fsi_dev->version)
	699	return 1;
	700	}
	701
	702	return 0;
	703	}
	704
356d8009 CB	705	int fsi_driver_register(struct fsi_driver *fsi_drv)
	706	{
	707	if (!fsi_drv)
	708	return -EINVAL;
	709	if (!fsi_drv->id_table)
	710	return -EINVAL;
	711
	712	return driver_register(&fsi_drv->drv);
	713	}
	714	EXPORT_SYMBOL_GPL(fsi_driver_register);
	715
	716	void fsi_driver_unregister(struct fsi_driver *fsi_drv)
	717	{
	718	driver_unregister(&fsi_drv->drv);
	719	}
	720	EXPORT_SYMBOL_GPL(fsi_driver_unregister);
	721
0508ad1f JK	722	struct bus_type fsi_bus_type = {
0508ad1f JK	723	.name = "fsi",
dd37eed7	724	.match = fsi_bus_match,
0508ad1f JK	725	};
	726	EXPORT_SYMBOL_GPL(fsi_bus_type);
	727
	728	static int fsi_init(void)
	729	{
	730	return bus_register(&fsi_bus_type);
	731	}
	732
	733	static void fsi_exit(void)
	734	{
	735	bus_unregister(&fsi_bus_type);
	736	}
	737
	738	module_init(fsi_init);
	739	module_exit(fsi_exit);