Hi,
On Tue, Jul 02, 2013 at 03:30:42PM +0530, Sourav Poddar wrote:
> >>+static int dra7xxx_qspi_setup(struct spi_device *spi)
> >>+{
> >>+ struct dra7xxx_qspi *qspi =
> >>+ spi_master_get_devdata(spi->master);
> >>+
> >>+ int clk_div;
> >>+
> >>+ if (!qspi->spi_max_frequency)
> >>+ clk_div = 0;
> >won't this generate division by zero ?
> >
> Yes, Probably only an error should be thrown here. ?
> since min clk_div should be kept at 1.
right, if spi_max_frequency isn't passed, this is a broken DT binding.
Bail out.
> >>+ pm_runtime_get_sync(qspi->dev);
> >>+
> >>+ /* disable SCLK */
> >>+ dra7xxx_writel(qspi, dra7xxx_readl(qspi, QSPI_SPI_CLOCK_CNTRL_REG)
> >>+ & ~QSPI_CLK_EN, QSPI_SPI_CLOCK_CNTRL_REG);
> >>+
> >>+ if (clk_div< 0) {
btw, add a space between clk_div and <
> >>+ dra7xxx_writel(qspi, *txbuf++, QSPI_SPI_DATA_REG);
> >>+ dra7xxx_writel(qspi, qspi->dc, QSPI_SPI_DC_REG);
> >>+ dra7xxx_writel(qspi, qspi->cmd | QSPI_WR_SNGL,
> >>+ QSPI_SPI_CMD_REG);
> >>+ status = dra7xxx_readl(qspi, QSPI_SPI_STATUS_REG);
> >>+ timeout = QSPI_TIMEOUT;
> >>+ while ((status& QSPI_WC_BUSY) != QSPI_XFER_DONE) {
> >do you really need to poll ? No IRQ available ?
> >
> There is an interrupt available, I will try using that.
look at how i2c-omap.c synchronizes interrupt with the transfer_msg
code. It just uses a wait_for_completion().
> >>+static int dra7xxx_qspi_start_transfer_one(struct spi_master *master,
> >>+ struct spi_message *m)
> >>+{
> >>+ struct dra7xxx_qspi *qspi = spi_master_get_devdata(master);
> >>+ struct spi_device *spi = m->spi;
> >>+ struct spi_transfer *t;
> >>+ int status = 0;
> >>+ int flags = 0;
> >>+
> >>+ /* setup command reg */
> >>+ qspi->cmd = 0;
> >>+ qspi->cmd |= QSPI_WLEN(8);
> >>+ qspi->cmd |= QSPI_EN_CS(0);
> >>+ qspi->cmd |= 0xfff;
> Since, we dont know the number of frame lenght that need to be
> transferred and it comes from the spi framework, we keep the frame
> lenght to maximum.
> Then depending on the count value above in while loop, we terminate
> our trasnfer.
what ? seriously didn't get what you meant.
--
balbi
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