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Commit 014c2abc authored by Jeremy Kerr's avatar Jeremy Kerr Committed by Greg Kroah-Hartman
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drivers/fsi: Add slave & master read/write APIs 



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: default avatarJeremy Kerr <jk@ozlabs.org>
Signed-off-by: default avatarJoel Stanley <joel@jms.id.au>
Signed-off-by: default avatarChris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0cbaa448

drivers/fsi/fsi-core.c

+92 −0
Original line number Diff line number Diff line
@@ -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;