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014c2abc53
Introduce functions to perform reads/writes on the slave address space; these simply pass the request on the slave's master with the correct link and slave ID. We implement these on top of similar helpers for the master. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
218 lines
4.6 KiB
C
218 lines
4.6 KiB
C
/*
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* FSI core driver
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*
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* Copyright (C) IBM Corporation 2016
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/device.h>
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#include <linux/fsi.h>
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#include <linux/idr.h>
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#include <linux/module.h>
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#include "fsi-master.h"
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static DEFINE_IDA(master_ida);
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struct fsi_slave {
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struct device dev;
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struct fsi_master *master;
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int id;
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int link;
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uint32_t size; /* size of slave address space */
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};
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#define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
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static int fsi_master_read(struct fsi_master *master, int link,
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uint8_t slave_id, uint32_t addr, void *val, size_t size);
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static int fsi_master_write(struct fsi_master *master, int link,
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uint8_t slave_id, uint32_t addr, const void *val, size_t size);
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/* FSI slave support */
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static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp,
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uint8_t *idp)
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{
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uint32_t addr = *addrp;
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uint8_t id = *idp;
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if (addr > slave->size)
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return -EINVAL;
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/* For 23 bit addressing, we encode the extra two bits in the slave
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* id (and the slave's actual ID needs to be 0).
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*/
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if (addr > 0x1fffff) {
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if (slave->id != 0)
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return -EINVAL;
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id = (addr >> 21) & 0x3;
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addr &= 0x1fffff;
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}
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*addrp = addr;
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*idp = id;
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return 0;
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}
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static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
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void *val, size_t size)
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{
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uint8_t id = slave->id;
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int rc;
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rc = fsi_slave_calc_addr(slave, &addr, &id);
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if (rc)
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return rc;
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return fsi_master_read(slave->master, slave->link, id,
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addr, val, size);
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}
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static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
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const void *val, size_t size)
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{
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uint8_t id = slave->id;
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int rc;
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rc = fsi_slave_calc_addr(slave, &addr, &id);
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if (rc)
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return rc;
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return fsi_master_write(slave->master, slave->link, id,
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addr, val, size);
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}
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static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
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{
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/* todo: initialise slave device, perform engine scan */
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return -ENODEV;
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}
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/* FSI master support */
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static int fsi_check_access(uint32_t addr, size_t size)
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{
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if (size != 1 && size != 2 && size != 4)
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return -EINVAL;
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if ((addr & 0x3) != (size & 0x3))
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return -EINVAL;
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return 0;
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}
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static int fsi_master_read(struct fsi_master *master, int link,
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uint8_t slave_id, uint32_t addr, void *val, size_t size)
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{
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int rc;
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rc = fsi_check_access(addr, size);
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if (rc)
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return rc;
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return master->read(master, link, slave_id, addr, val, size);
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}
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static int fsi_master_write(struct fsi_master *master, int link,
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uint8_t slave_id, uint32_t addr, const void *val, size_t size)
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{
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int rc;
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rc = fsi_check_access(addr, size);
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if (rc)
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return rc;
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return master->write(master, link, slave_id, addr, val, size);
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}
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static int fsi_master_scan(struct fsi_master *master)
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{
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int link;
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for (link = 0; link < master->n_links; link++)
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fsi_slave_init(master, link, 0);
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return 0;
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}
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int fsi_master_register(struct fsi_master *master)
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{
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int rc;
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if (!master)
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return -EINVAL;
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master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);
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dev_set_name(&master->dev, "fsi%d", master->idx);
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rc = device_register(&master->dev);
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if (rc) {
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ida_simple_remove(&master_ida, master->idx);
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return rc;
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}
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fsi_master_scan(master);
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return 0;
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}
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EXPORT_SYMBOL_GPL(fsi_master_register);
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void fsi_master_unregister(struct fsi_master *master)
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{
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if (master->idx >= 0) {
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ida_simple_remove(&master_ida, master->idx);
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master->idx = -1;
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}
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device_unregister(&master->dev);
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}
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EXPORT_SYMBOL_GPL(fsi_master_unregister);
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/* FSI core & Linux bus type definitions */
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static int fsi_bus_match(struct device *dev, struct device_driver *drv)
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{
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struct fsi_device *fsi_dev = to_fsi_dev(dev);
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struct fsi_driver *fsi_drv = to_fsi_drv(drv);
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const struct fsi_device_id *id;
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if (!fsi_drv->id_table)
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return 0;
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for (id = fsi_drv->id_table; id->engine_type; id++) {
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if (id->engine_type != fsi_dev->engine_type)
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continue;
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if (id->version == FSI_VERSION_ANY ||
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id->version == fsi_dev->version)
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return 1;
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}
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return 0;
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}
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struct bus_type fsi_bus_type = {
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.name = "fsi",
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.match = fsi_bus_match,
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};
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EXPORT_SYMBOL_GPL(fsi_bus_type);
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static int fsi_init(void)
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{
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return bus_register(&fsi_bus_type);
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}
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static void fsi_exit(void)
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{
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bus_unregister(&fsi_bus_type);
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}
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module_init(fsi_init);
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module_exit(fsi_exit);
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