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drivers/fsi: Add slave & master read/write APIs

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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>
This commit is contained in:
Jeremy Kerr 2017-06-06 16:08:40 -05:00 committed by Greg Kroah-Hartman
parent 0cbaa44841
commit 014c2abc53
1 changed files with 92 additions and 0 deletions
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92
drivers/fsi/fsi-core.c
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@ -32,7 +32,64 @@ struct fsi_slave {
#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);
/* 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_init(struct fsi_master *master, int link, uint8_t id)
{
/* todo: initialise slave device, perform engine scan */
@ -41,6 +98,41 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
}
/* 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_scan(struct fsi_master *master)
{
int link;