From: Christopher Bostic <cbostic@linux.vnet.ibm.com>
To: robh+dt@kernel.org, mark.rutland@arm.com, linux@armlinux.org.uk,
rostedt@goodmis.org, mingo@redhat.com,
gregkh@linuxfoundation.org, devicetree@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Cc: Jeremy Kerr <jk@ozlabs.org>,
joel@jms.id.au, linux-kernel@vger.kernel.org, andrew@aj.id.au,
alistair@popple.id.au, benh@kernel.crashing.org,
Chris Bostic <cbostic@linux.vnet.ibm.com>
Subject: [PATCH v4 05/23] drivers/fsi: Add slave & master read/write APIs
Date: Wed, 29 Mar 2017 12:43:22 -0500 [thread overview]
Message-ID: <20170329174340.89109-6-cbostic@linux.vnet.ibm.com> (raw)
In-Reply-To: <20170329174340.89109-1-cbostic@linux.vnet.ibm.com>
From: Jeremy Kerr <jk@ozlabs.org>
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>
---
drivers/fsi/fsi-core.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)
diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 4bbca95..32698ed 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -32,6 +32,11 @@ 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);
+
/* crc helpers */
static const uint8_t crc4_tab[] = {
0x0, 0x7, 0xe, 0x9, 0xb, 0xc, 0x5, 0x2,
@@ -57,6 +62,58 @@ uint8_t fsi_crc4(uint8_t c, uint64_t x, int bits)
EXPORT_SYMBOL_GPL(fsi_crc4);
/* 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 */
@@ -65,6 +122,41 @@ 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;
--
1.8.2.2
next prev parent reply other threads:[~2017-03-29 17:44 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-29 17:43 [PATCH v4 00/23] FSI device driver implementation Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 01/23] drivers/fsi: Add fsi master definition Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 02/23] drivers/fsi: Add slave definition Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 03/23] drivers/fsi: Add empty master scan Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 04/23] drivers/fsi: Add crc4 helpers Christopher Bostic
2017-03-29 17:43 ` Christopher Bostic [this message]
2017-03-29 17:43 ` [PATCH v4 06/23] drivers/fsi: Set up links for slave communication Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 07/23] drivers/fsi: Implement slave initialisation Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 08/23] drivers/fsi: Set slave SMODE to init communication Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 09/23] drivers/fsi: scan slaves & register devices Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 10/23] drivers/fsi: Add device read/write/peek API Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 11/23] drivers/fsi: Add master unscan Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 12/23] drivers/fsi: Add documentation for GPIO bindings Christopher Bostic
2017-04-03 15:24 ` Rob Herring
2017-03-29 17:43 ` [PATCH v4 13/23] drivers/fsi: Add client driver register utilities Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 14/23] drivers/fsi: Add sysfs files for FSI master & slave accesses Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 15/23] drivers/fsi: expose direct-access slave API Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 16/23] drivers/fsi: Add tracepoints for low-level operations Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 17/23] drivers/fsi: Add error handling for slave communication errors Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 18/23] drivers/fsi: Document FSI master sysfs files in ABI Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 19/23] drivers/fsi: Add GPIO based FSI master Christopher Bostic
2017-03-30 5:48 ` Joel Stanley
2017-03-30 18:15 ` Christopher Bostic
2017-03-30 20:50 ` Benjamin Herrenschmidt
2017-04-04 17:32 ` Christopher Bostic
2017-04-04 22:19 ` Benjamin Herrenschmidt
2017-04-05 1:24 ` Christopher Bostic
2017-04-09 21:22 ` Christopher Bostic
2017-04-09 21:41 ` Benjamin Herrenschmidt
2017-04-09 21:53 ` Benjamin Herrenschmidt
2017-04-09 21:55 ` Benjamin Herrenschmidt
2017-03-30 22:57 ` Joel Stanley
2017-03-29 17:43 ` [PATCH v4 20/23] drivers/fsi/gpio: Add tracepoints for GPIO master Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 21/23] drivers/fsi: Add SCOM FSI client device driver Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 22/23] drivers/fsi: Add hub master support Christopher Bostic
2017-03-29 17:43 ` [PATCH v4 23/23] drivers/fsi: Use asynchronous slave mode Christopher Bostic
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