drivers/fsi: Add device read/write/peek API

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

Includes contributions from Christopher Bostic
<cbostic@linux.vnet.ibm.com> and Edward A. James <eajames@us.ibm.com>.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index eac0bc4f71e90f9b2eca51fc4f3409caaa882640..d7a6e762527f6fb4dd0ffbd675a86b1228191f05 100644 (file)
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -34,6 +34,8 @@
 #define FSI_SLAVE_CONF_CRC_MASK                GENMASK(3, 0)
 #define FSI_SLAVE_CONF_DATA_BITS       28
 
+#define FSI_PEEK_BASE                  0x410
+
 static const int engine_page_size = 0x400;
 
 #define FSI_SLAVE_BASE                 0x800
@@ -75,8 +77,54 @@ 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);
+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_device_read() / fsi_device_write() / fsi_device_peek()
+ *
+ * FSI endpoint-device support
+ *
+ * Read / write / peek accessors for a client
+ *
+ * Parameters:
+ * dev:  Structure passed to FSI client device drivers on probe().
+ * addr: FSI address of given device.  Client should pass in its base address
+ *       plus desired offset to access its register space.
+ * val:  For read/peek this is the value read at the specified address. For
+ *       write this is value to write to the specified address.
+ *       The data in val must be FSI bus endian (big endian).
+ * size: Size in bytes of the operation.  Sizes supported are 1, 2 and 4 bytes.
+ *       Addresses must be aligned on size boundaries or an error will result.
+ */
+int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val,
+               size_t size)
+{
+       if (addr > dev->size || size > dev->size || addr > dev->size - size)
+               return -EINVAL;
 
-/* FSI endpoint-device support */
+       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 || size > dev->size || addr > dev->size - 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)
 {

diff --git a/include/linux/fsi.h b/include/linux/fsi.h
index efa55ba6cb3904339181afa9d90776b2b110ae5c..66bce4851ff6e8a8696c36bf842ff16bb76dd6fd 100644 (file)
--- 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;
@@ -40,7 +46,6 @@ struct fsi_device_id {
 #define FSI_DEVICE_VERSIONED(t, v) \
        .engine_type = (t), .version = (v),
 
-
 struct fsi_driver {
        struct device_driver            drv;
        const struct fsi_device_id      *id_table;