[PATCH v3 11/18] drivers/fsi: Add device read/write/peek functions

From: Christopher Bostic
Date: Wed Feb 01 2017 - 11:59:52 EST


From: Jeremy Kerr <jk@xxxxxxxxxx>

This change introduces the fsi device API: simple read, write and peek
accessors for the devices' address spaces.

Includes contributions from Chris Bostic <cbostic@xxxxxxxxxx>

Signed-off-by: Jeremy Kerr <jk@xxxxxxxxxx>
Signed-off-by: Chris Bostic <cbostic@xxxxxxxxxx>
---
drivers/fsi/fsi-core.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/fsi.h | 6 ++++++
2 files changed, 53 insertions(+)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index f7ef993..3119aa1 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -35,6 +35,8 @@
#define FSI_SLAVE_CONF_CRC_MASK 0x0000000f
#define FSI_SLAVE_CONF_DATA_BITS 28

+#define FSI_PEEK_BASE 0x410
+
static const int engine_page_size = 0x400;

static DEFINE_IDA(master_ida);
@@ -48,8 +50,46 @@ struct fsi_slave {

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

+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 endpoint-device support */

+int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val,
+ size_t size)
+{
+ if (addr > dev->size)
+ return -EINVAL;
+
+ if (addr + size > dev->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)
+ return -EINVAL;
+
+ if (addr + size > dev->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);
@@ -81,6 +121,13 @@ static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
slave->id, addr, val, size);
}

+static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
+ const void *val, size_t size)
+{
+ return slave->master->write(slave->master, slave->link,
+ slave->id, addr, val, size);
+}
+
static int fsi_slave_scan(struct fsi_slave *slave)
{
uint32_t engine_addr;
diff --git a/include/linux/fsi.h b/include/linux/fsi.h
index efa55ba..273945d 100644
--- a/include/linux/fsi.h
+++ b/include/linux/fsi.h
@@ -27,6 +27,12 @@ struct fsi_device {
uint32_t size;
};

+extern int fsi_device_read(struct fsi_device *dev, uint32_t addr,
+ void *val, size_t size);
+extern int fsi_device_write(struct fsi_device *dev, uint32_t addr,
+ const void *val, size_t size);
+extern int fsi_device_peek(struct fsi_device *dev, void *val);
+
struct fsi_device_id {
u8 engine_type;
u8 version;
--
1.8.2.2