Re: [PATCHv2 2/3] fpga: altera-cvp: Preparation for V2 parts.

From: Thor Thayer
Date: Tue Jul 23 2019 - 10:38:43 EST


Hi Moritz,

On 7/21/19 7:59 PM, Moritz Fischer wrote:
Thor,

On Tue, Jul 16, 2019 at 05:48:06PM -0500, thor.thayer@xxxxxxxxxxxxxxx wrote:
From: Thor Thayer <thor.thayer@xxxxxxxxxxxxxxx>

In preparation for adding newer V2 parts that use a FIFO,
reorganize altera_cvp_chk_error() and change the write
function to block based.
V2 parts have a block size matching the FIFO while older
V1 parts write a 32 bit word at a time.

Signed-off-by: Thor Thayer <thor.thayer@xxxxxxxxxxxxxxx>
---
v2 Remove inline function declaration
Reverse Christmas Tree format for local variables
---
drivers/fpga/altera-cvp.c | 72 ++++++++++++++++++++++++++++++-----------------
1 file changed, 46 insertions(+), 26 deletions(-)

diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
index b78c90580071..37419d6b9915 100644
--- a/drivers/fpga/altera-cvp.c
+++ b/drivers/fpga/altera-cvp.c
@@ -140,6 +140,41 @@ static int altera_cvp_wait_status(struct altera_cvp_conf *conf, u32 status_mask,
return -ETIMEDOUT;
}
+static int altera_cvp_chk_error(struct fpga_manager *mgr, size_t bytes)
+{
+ struct altera_cvp_conf *conf = mgr->priv;
+ u32 val;
+
+ /* STEP 10 (optional) - check CVP_CONFIG_ERROR flag */
+ altera_read_config_dword(conf, VSE_CVP_STATUS, &val);
Same as in the other email, why can we ignore return values here. I
think the original code probably did that already.

Yes, I actually didn't make any changes to this function. You can see I moved it from below since it is used in the following function.

I'm not checking the return code from any of the read/write functions since the original driver didn't. Would you prefer I check and issue a warning?

Thanks for reviewing!

+ if (val & VSE_CVP_STATUS_CFG_ERR) {
+ dev_err(&mgr->dev, "CVP_CONFIG_ERROR after %zu bytes!\n",
+ bytes);
+ return -EPROTO;
+ }
+ return 0;
+}
+
+static int altera_cvp_send_block(struct altera_cvp_conf *conf,
+ const u32 *data, size_t len)
+{
+ u32 mask, words = len / sizeof(u32);
+ int i, remainder;
+
+ for (i = 0; i < words; i++)
+ conf->write_data(conf, *data++);
+
+ /* write up to 3 trailing bytes, if any */
+ remainder = len % sizeof(u32);
+ if (remainder) {
+ mask = BIT(remainder * 8) - 1;
+ if (mask)
+ conf->write_data(conf, *data & mask);
+ }
+
+ return 0;
+}
+
static int altera_cvp_teardown(struct fpga_manager *mgr,
struct fpga_image_info *info)
{
@@ -262,39 +297,29 @@ static int altera_cvp_write_init(struct fpga_manager *mgr,
return 0;
}
-static inline int altera_cvp_chk_error(struct fpga_manager *mgr, size_t bytes)
-{
- struct altera_cvp_conf *conf = mgr->priv;
- u32 val;
-
- /* STEP 10 (optional) - check CVP_CONFIG_ERROR flag */
- altera_read_config_dword(conf, VSE_CVP_STATUS, &val);
- if (val & VSE_CVP_STATUS_CFG_ERR) {
- dev_err(&mgr->dev, "CVP_CONFIG_ERROR after %zu bytes!\n",
- bytes);
- return -EPROTO;
- }
- return 0;
-}
-
static int altera_cvp_write(struct fpga_manager *mgr, const char *buf,
size_t count)
{
struct altera_cvp_conf *conf = mgr->priv;
+ size_t done, remaining, len;
const u32 *data;
- size_t done, remaining;
int status = 0;
- u32 mask;
/* STEP 9 - write 32-bit data from RBF file to CVP data register */
data = (u32 *)buf;
remaining = count;
done = 0;
- while (remaining >= 4) {
- conf->write_data(conf, *data++);
- done += 4;
- remaining -= 4;
+ while (remaining) {
+ if (remaining >= sizeof(u32))
+ len = sizeof(u32);
+ else
+ len = remaining;
+
+ altera_cvp_send_block(conf, data, len);
+ data++;
+ done += len;
+ remaining -= len;
/*
* STEP 10 (optional) and STEP 11
@@ -312,11 +337,6 @@ static int altera_cvp_write(struct fpga_manager *mgr, const char *buf,
}
}
- /* write up to 3 trailing bytes, if any */
- mask = BIT(remaining * 8) - 1;
- if (mask)
- conf->write_data(conf, *data & mask);
-
if (altera_cvp_chkcfg)
status = altera_cvp_chk_error(mgr, count);
--
2.7.4

Cheers,
Moritz