Re: [PATCH v6 09/23] drivers/fsi: scan slaves & register devices

From: Christopher Bostic
Date: Wed May 10 2017 - 14:24:53 EST




On 5/10/17 2:30 AM, Joel Stanley wrote:
On Tue, Apr 11, 2017 at 5:16 AM, Christopher Bostic
<cbostic@xxxxxxxxxxxxxxxxxx> wrote:
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 Chris Bostic <cbostic@xxxxxxxxxxxxxxxxxx>

Signed-off-by: Jeremy Kerr <jk@xxxxxxxxxx>
Signed-off-by: Chris Bostic <cbostic@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
---
drivers/fsi/fsi-core.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++--
include/linux/fsi.h | 4 ++
2 files changed, 128 insertions(+), 3 deletions(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index b7b138b..a8faa89 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -21,6 +21,19 @@

#include "fsi-master.h"

+#define FSI_SLAVE_CONF_NEXT_MASK 0x80000000
+#define FSI_SLAVE_CONF_SLOTS_MASK 0x00ff0000
+#define FSI_SLAVE_CONF_SLOTS_SHIFT 16
+#define FSI_SLAVE_CONF_VERSION_MASK 0x0000f000
+#define FSI_SLAVE_CONF_VERSION_SHIFT 12
+#define FSI_SLAVE_CONF_TYPE_MASK 0x00000ff0
+#define FSI_SLAVE_CONF_TYPE_SHIFT 4
+#define FSI_SLAVE_CONF_CRC_SHIFT 4
+#define FSI_SLAVE_CONF_CRC_MASK 0x0000000f
+#define FSI_SLAVE_CONF_DATA_BITS 28
You could use GENAMSK for these. It would make it easier to check eg.
that 0x00ff0000 needs to be shifted by 16.

Hi Joel,

OK will update to use GENMASK.

+
+static const int engine_page_size = 0x400;
+
#define FSI_SLAVE_BASE 0x800

/*
@@ -61,6 +74,30 @@ 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;
+}
+
/* crc helpers */
static const uint8_t crc4_tab[] = {
0x0, 0x7, 0xe, 0x9, 0xb, 0xc, 0x5, 0x2,
@@ -138,6 +175,91 @@ 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 = fsi_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_info(&slave->dev,
+ "engine[%i]: type %x, version %x, addr %x size %x\n",
+ dev->unit, dev->engine_type, version,
+ dev->addr, dev->size);
This produces a lot of noise in the kernel log. I suggest making it
drv_dbg if you require it. If you don't then remove it.

Will need for debug purposes so will change to dev_dbg( ).

+
+ 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)
{
@@ -253,9 +375,8 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
return rc;
}

- /* todo: perform engine scan */
-
- return rc;
+ fsi_slave_scan(slave);
+ return 0;
You don't check the return value of fsi_slave_scan.
Will correct.

Thanks,
-Chris

}

/* FSI master support */
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