Thread (23 messages) 23 messages, 6 authors, 2015-08-25

[PATCH linux-next v4 5/5] mtd: atmel-quadspi: add driver for Atmel QSPI controller

From: marex@denx.de (Marek Vasut)
Date: 2015-08-24 17:45:41
Also in: linux-devicetree, linux-spi, lkml

On Monday, August 24, 2015 at 07:04:38 PM, Cyrille Pitchen wrote:
Hi Marek,
Hi!
Le 24/08/2015 13:03, Marek Vasut a ?crit :
quoted
On Monday, August 24, 2015 at 12:14:00 PM, Cyrille Pitchen wrote:
quoted
This driver add support to the new Atmel QSPI controller embedded into
sama5d2x SoCs. It expects a NOR memory to be connected to the QSPI
controller.
[...]
quoted
quoted
+	/* Compute address parameters */
+	switch (cmd->enable.bits.address) {
+	case 4:
+		ifr |= QSPI_IFR_ADDRL;
+		/*break;*/ /* fallback to the 24bit address case */
What's this commented out bit of code for ? :-)
I just wanted to stress out there was no missing "break;".
I've reworded the comment to:
/* No "break" on purpose: fallback to the 24bit address case. */
Oh, the address is in bytes . I see, yes, it makes sense to be more
explicit here about the purpose of the fallback. I think this change
in the comment will make it easier for everyone who comes back in a
few years and reads this code.
quoted
quoted
+	case 3:
+		iar = (cmd->enable.bits.data) ? 0 : cmd->address;
+		ifr |= QSPI_IFR_ADDREN;
+		break;
+	case 0:
+		break;
+	default:
+		return -EINVAL;
+	}
[...]
quoted
+no_data:
+	/* Poll INSTRuction End status */
+	sr = qspi_readl(aq, QSPI_SR);
+	if (sr & QSPI_SR_INSTRE)
+		return err;
+
+	/* Wait for INSTRuction End interrupt */
+	init_completion(&aq->completion);
You should use reinit_completion() in the code. init_completion()
should be used only in the probe() function and nowhere else.
Alright. In the next version I'll rename the "completion" member of
struct atmel_qspi into "cmd_completion". Also I'll add another
dma_completion member in this very same structure to replace the local
"struct completion completion" in atmel_qspi_run_dma_transfer().

Then I'll call init_completion() on both cmd_completion and dma_completion
only from atmel_qspi_probe() and reinit_completion() elsewhere.
quoted
quoted
+	aq->pending = 0;
+	qspi_writel(aq, QSPI_IER, QSPI_SR_INSTRE);
+	if (!wait_for_completion_timeout(&aq->completion,
+					 msecs_to_jiffies(1000)))
+		err = -ETIMEDOUT;
+	qspi_writel(aq, QSPI_IDR, QSPI_SR_INSTRE);
+
+	return err;
+}
[...]

Hope this helps :)
Indeed, it does! I still work on the next version of this series to take
all your comments into account.
Thanks :)
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