On Thu, Jul 18, 2013 at 03:31:26PM +0530, Sourav Poddar wrote:
> QSPI is a kind of spi module that allows single,
> dual and quad read access to external spi devices. The module
> has a memory mapped interface which provide direct interface
> for accessing data form external spi devices.
Have you seen the ongoing thread about SPI buses with extra data lines?
How does this driver fit in with that?
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -46,6 +46,7 @@ obj-$(CONFIG_SPI_OCTEON) += spi-octeon.o
> obj-$(CONFIG_SPI_OMAP_UWIRE) += spi-omap-uwire.o
> obj-$(CONFIG_SPI_OMAP_100K) += spi-omap-100k.o
> obj-$(CONFIG_SPI_OMAP24XX) += spi-omap2-mcspi.o
> +obj-$(CONFIG_QSPI_DRA7xxx) += spi-ti-qspi.o
> obj-$(CONFIG_SPI_ORION) += spi-orion.o
> obj-$(CONFIG_SPI_PL022) += spi-pl022.o
> obj-$(CONFIG_SPI_PPC4xx) += spi-ppc4xx.o
Please use SPI_ like the other drivers.
> +static int ti_qspi_prepare_xfer(struct spi_master *master)
> +{
> + struct ti_qspi *qspi = spi_master_get_devdata(master);
> + int ret;
> +
> + ret = pm_runtime_get_sync(qspi->dev);
> + if (ret < 0) {
> + dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
> + return ret;
> + }
> +
> + return 0;
> +}
This is a very common pattern, it should probably be factored out into
the core, probably not even as ops but rather as an actual feature.
> + list_for_each_entry(t, &m->transfers, transfer_list) {
> + qspi->cmd |= QSPI_WLEN(t->bits_per_word);
> + qspi->cmd |= QSPI_WC_CMD_INT_EN;
> +
> + ret = qspi_transfer_msg(qspi, t);
> + if (ret) {
> + dev_dbg(qspi->dev, "transfer message failed\n");
> + return -EINVAL;
> + }
> +
> + m->actual_length += t->len;
> +
> + if (list_is_last(&t->transfer_list, &m->transfers))
> + goto out;
> + }
The use of list_is_last() here is *realy* strange - what's going on
there?
> +static irqreturn_t ti_qspi_isr(int irq, void *dev_id)
> +{
> + struct ti_qspi *qspi = dev_id;
> + u16 mask, stat;
> +
> + irqreturn_t ret = IRQ_HANDLED;
> +
> + spin_lock(&qspi->lock);
> +
> + stat = ti_qspi_readl(qspi, QSPI_SPI_STATUS_REG);
> + mask = ti_qspi_readl(qspi, QSPI_INTR_ENABLE_SET_REG);
> +
> + if (stat && mask)
> + ret = IRQ_WAKE_THREAD;
> +
> + spin_unlock(&qspi->lock);
> +
> + return ret;
According to the above code we might interrupt for masked events...
that's a bit worrying isn't it?
> + ret = devm_request_threaded_irq(&pdev->dev, irq, ti_qspi_isr,
> + ti_qspi_threaded_isr, IRQF_NO_SUSPEND | IRQF_ONESHOT,
> + dev_name(&pdev->dev), qspi);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
> + irq);
> + goto free_master;
> + }
Standard question about devm_request_threaded_irq() - how can we be
certain it's safe to use during removal?
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