[PATCH v8 09/24] drivers/fsi: scan slaves & register devices

From: Christopher Bostic
Date: Tue Jun 06 2017 - 17:12:49 EST


From: Jeremy Kerr <jk@xxxxxxxxxx>

Now that we have fsi_slave devices, scan each for endpoints, and
register them on the fsi bus.

Includes contributions from Christopher Bostic
<cbostic@xxxxxxxxxxxxxxxxxx>.

Signed-off-by: Jeremy Kerr <jk@xxxxxxxxxx>
Signed-off-by: Christopher Bostic <cbostic@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
---
drivers/fsi/fsi-core.c | 128 ++++++++++++++++++++++++++++++++++++++++++++++++-
include/linux/fsi.h | 4 ++
2 files changed, 131 insertions(+), 1 deletion(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 04795f2..eac0bc4 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -19,9 +19,23 @@
#include <linux/idr.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/bitops.h>

#include "fsi-master.h"

+#define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31)
+#define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16)
+#define FSI_SLAVE_CONF_SLOTS_SHIFT 16
+#define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12)
+#define FSI_SLAVE_CONF_VERSION_SHIFT 12
+#define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4)
+#define FSI_SLAVE_CONF_TYPE_SHIFT 4
+#define FSI_SLAVE_CONF_CRC_SHIFT 4
+#define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0)
+#define FSI_SLAVE_CONF_DATA_BITS 28
+
+static const int engine_page_size = 0x400;
+
#define FSI_SLAVE_BASE 0x800

/*
@@ -62,6 +76,30 @@ static int fsi_master_read(struct fsi_master *master, int link,
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 endpoint-device support */
+
+static void fsi_device_release(struct device *_device)
+{
+ struct fsi_device *device = to_fsi_dev(_device);
+
+ kfree(device);
+}
+
+static struct fsi_device *fsi_create_device(struct fsi_slave *slave)
+{
+ struct fsi_device *dev;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return NULL;
+
+ dev->dev.parent = &slave->dev;
+ dev->dev.bus = &fsi_bus_type;
+ dev->dev.release = fsi_device_release;
+
+ return dev;
+}
+
/* FSI slave support */
static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp,
uint8_t *idp)
@@ -115,6 +153,91 @@ static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
addr, val, size);
}

+static int fsi_slave_scan(struct fsi_slave *slave)
+{
+ uint32_t engine_addr;
+ uint32_t conf;
+ int rc, i;
+
+ /*
+ * scan engines
+ *
+ * We keep the peek mode and slave engines for the core; so start
+ * at the third slot in the configuration table. We also need to
+ * skip the chip ID entry at the start of the address space.
+ */
+ engine_addr = engine_page_size * 3;
+ for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) {
+ uint8_t slots, version, type, crc;
+ struct fsi_device *dev;
+
+ rc = fsi_slave_read(slave, (i + 1) * sizeof(conf),
+ &conf, sizeof(conf));
+ if (rc) {
+ dev_warn(&slave->dev,
+ "error reading slave registers\n");
+ return -1;
+ }
+ conf = be32_to_cpu(conf);
+
+ crc = crc4(0, conf, 32);
+ if (crc) {
+ dev_warn(&slave->dev,
+ "crc error in slave register at 0x%04x\n",
+ i);
+ return -1;
+ }
+
+ slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK)
+ >> FSI_SLAVE_CONF_SLOTS_SHIFT;
+ version = (conf & FSI_SLAVE_CONF_VERSION_MASK)
+ >> FSI_SLAVE_CONF_VERSION_SHIFT;
+ type = (conf & FSI_SLAVE_CONF_TYPE_MASK)
+ >> FSI_SLAVE_CONF_TYPE_SHIFT;
+
+ /*
+ * Unused address areas are marked by a zero type value; this
+ * skips the defined address areas
+ */
+ if (type != 0 && slots != 0) {
+
+ /* create device */
+ dev = fsi_create_device(slave);
+ if (!dev)
+ return -ENOMEM;
+
+ dev->slave = slave;
+ dev->engine_type = type;
+ dev->version = version;
+ dev->unit = i;
+ dev->addr = engine_addr;
+ dev->size = slots * engine_page_size;
+
+ dev_dbg(&slave->dev,
+ "engine[%i]: type %x, version %x, addr %x size %x\n",
+ dev->unit, dev->engine_type, version,
+ dev->addr, dev->size);
+
+ dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x",
+ slave->master->idx, slave->link,
+ slave->id, i - 2);
+
+ rc = device_register(&dev->dev);
+ if (rc) {
+ dev_warn(&slave->dev, "add failed: %d\n", rc);
+ put_device(&dev->dev);
+ }
+ }
+
+ engine_addr += slots * engine_page_size;
+
+ if (!(conf & FSI_SLAVE_CONF_NEXT_MASK))
+ break;
+ }
+
+ return 0;
+}
+
/* Encode slave local bus echo delay */
static inline uint32_t fsi_smode_echodly(int x)
{
@@ -230,7 +353,10 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
return rc;
}

- /* todo: perform engine scan */
+ rc = fsi_slave_scan(slave);
+ if (rc)
+ dev_dbg(&master->dev, "failed during slave scan with: %d\n",
+ rc);

return rc;
}
diff --git a/include/linux/fsi.h b/include/linux/fsi.h
index 273cbf6..efa55ba 100644
--- a/include/linux/fsi.h
+++ b/include/linux/fsi.h
@@ -21,6 +21,10 @@ struct fsi_device {
struct device dev;
u8 engine_type;
u8 version;
+ u8 unit;
+ struct fsi_slave *slave;
+ uint32_t addr;
+ uint32_t size;
};

struct fsi_device_id {
--
1.8.2.2