On Monday 29 July 2013 03:50 PM, Felipe Balbi wrote:
Hi,
On Mon, Jul 29, 2013 at 03:42:03PM +0530, Sourav Poddar wrote:
+ frame_length = (m->frame_length<< 3) / spi->bits_per_word;
there's another way to optimize this. If you assume bits_per_word to
always be power of two you can:
frame_length = (m->frame_length<< 3)>> __ffs(spi->bits_per_word);
but that would need a comment stating that you're assuming bits_per_word
to always be a power of two. Not sure if this is a correct assumption.
I dont think it will be a correct assumption, since our controller is
flexible to
handle anything from 1 to 128 as bits_per_word.
right, but can the framework handle non-power-of-two bits_per_word ?
The only limitation I see is the max bits_per_word, which is 32.
Though, I did set "master->bits_per_word_mask" as power of 2
in my probe.
+ spin_unlock(&qspi->lock);
You should, before releasing the lock, mask your IRQs, so that you can
get rid of IRQF_ONESHOT. Unmask them before returning from the IRQ
thread.
Sorry, did not get you here?
I am reading interrupt status register before and clearing them in
the threaded irq.
you need to mask the IRQs, clear WC and FIRQ in IRQENABLE register...
set them back at the end of the thread handler.
Ok
+static int ti_qspi_probe(struct platform_device *pdev)
+{
+ struct ti_qspi *qspi;
+ struct spi_master *master;
+ struct resource *r;
+ struct device_node *np = pdev->dev.of_node;
+ u32 max_freq;
+ int ret = 0, num_cs, irq;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*qspi));
+ if (!master)
+ return -ENOMEM;
+
+ master->mode_bits = SPI_CPOL | SPI_CPHA;
+
+ master->num_chipselect = 1;
again with the num_chipselect = 1 ? IIRC this controller has 4
chipselects, just read 24.5.1 on your TRM.
this is unnecessary. I intended to configure chip selects through
dt)as done below).
Will remove.
which brings me to the point of:
Do you review your own code before sending it out ? Doesn't look like...
+ irq = platform_get_irq(pdev, 0);
+ if (irq< 0) {
+ dev_err(&pdev->dev, "no irq resource?\n");
+ return irq;
+ }
+
+ spin_lock_init(&qspi->lock);
+
+ qspi->base = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(qspi->base)) {
+ ret = PTR_ERR(qspi->base);
+ goto free_master;
+ }
+
+ ret = devm_request_threaded_irq(&pdev->dev, irq, ti_qspi_isr,
+ ti_qspi_threaded_isr, IRQF_NO_SUSPEND | IRQF_ONESHOT,
why do you need IRQF_NO_SUSPEND ?
I should get away with this.
why ? Do you need or do you *not* need it ? And in either case, why ?
I was thinking, this will keep the irqs up even when we are
hitting suspend, we will not be prepared to handle it. ?
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