On Monday 08 July 2013 08:02 PM, Felipe Balbi wrote:
Hi,

On Mon, Jul 08, 2013 at 07:12:59PM +0530, Sourav Poddar wrote:
+static inline unsigned long dra7xxx_readl(struct dra7xxx_qspi *qspi,
+               unsigned long reg)
+{
+       return readl(qspi->base + reg);
+}
+
+static inline void dra7xxx_writel(struct dra7xxx_qspi *qspi,
+               unsigned long val, unsigned long reg)
+{
+       writel(val, qspi->base + reg);
+}
+
+static inline unsigned long dra7xxx_readl_data(struct dra7xxx_qspi *qspi,
+               unsigned long reg, int wlen)
+{
+       switch (wlen) {
+       case 8:
+               return readw(qspi->base + reg);
+               break;
+       case 16:
+               return readb(qspi->base + reg);
+               break;
+       case 32:
+               return readl(qspi->base + reg);
+               break;
+       default:
+               return -1;
return -EINVAL ? or some other error code ?

+       }
+}
+
+static inline void dra7xxx_writel_data(struct dra7xxx_qspi *qspi,
+               unsigned long val, unsigned long reg, int wlen)
+{
+       switch (wlen) {
+       case 8:
+               writew(val, qspi->base + reg);
+               break;
+       case 16:
+               writeb(val, qspi->base + reg);
+               break;
+       case 32:
+               writeb(val, qspi->base + reg);
+               break;
+       default:
+               dev_dbg(qspi->dev, "word lenght out of range");
+               break;
+       }
+}
+
+static int dra7xxx_qspi_setup(struct spi_device *spi)
+{
+       struct dra7xxx_qspi     *qspi = spi_master_get_devdata(spi->master);
+       int clk_div = 0;
+       u32 clk_ctrl_reg, clk_rate;
+
+       clk_rate = clk_get_rate(qspi->fclk);
+
+       if (!qspi->spi_max_frequency) {
+               dev_err(qspi->dev, "spi max frequency not defined\n");
+               return -1;
same here

+       } else
this needs to have curly braces too, per CodingStyle

+               clk_div = (clk_rate / qspi->spi_max_frequency) - 1;
+
+       dev_dbg(qspi->dev, "%s: hz: %d, clock divider %d\n", __func__,
+                       qspi->spi_max_frequency, clk_div);
+
+       pm_runtime_get_sync(qspi->dev);
+
+       clk_ctrl_reg = dra7xxx_readl(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
+
+       clk_ctrl_reg&= ~QSPI_CLK_EN;
+
+       /* disable SCLK */
+       dra7xxx_writel(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
+
+       if (clk_div<  0) {
+               dev_dbg(qspi->dev, "%s: clock divider<  0, using /1 divider\n",
+                               __func__);
+               clk_div = 1;
+       }
+
+       if (clk_div>  QSPI_CLK_DIV_MAX) {
+               dev_dbg(qspi->dev, "%s: clock divider>%d , using /%d divider\n",
+                       __func__, QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
+               clk_div = QSPI_CLK_DIV_MAX;
+       }
+
+       /* enable SCLK */
+       dra7xxx_writel(qspi, QSPI_CLK_EN | clk_div, QSPI_SPI_CLOCK_CNTRL_REG);
+
+       pm_runtime_mark_last_busy(qspi->dev);
+       pm_runtime_put_autosuspend(qspi->dev);
+
+       return 0;
+}
+
+static int dra7xxx_qspi_prepare_xfer(struct spi_master *master)
+{
+       struct dra7xxx_qspi *qspi = spi_master_get_devdata(master);
+
+       pm_runtime_get_sync(qspi->dev);
not going to check return value ?

+       return 0;
+}
+
+static int dra7xxx_qspi_unprepare_xfer(struct spi_master *master)
+{
+       struct dra7xxx_qspi *qspi = spi_master_get_devdata(master);
+
+       pm_runtime_mark_last_busy(qspi->dev);
+       pm_runtime_put_autosuspend(qspi->dev);
what about on these two ?

Just realised this, pm_runtime_mark_last_busy does not need a check, it returns nothing.
+       return 0;
+}
+
+static int qspi_write_msg(struct dra7xxx_qspi *qspi, struct spi_transfer *t)
+{
+       const u8 *txbuf;
+       int wlen, count;
+
+       count = t->len;
+       txbuf = t->tx_buf;
+       wlen = t->bits_per_word;
+
+       while (count--) {
+               dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
+                       qspi->cmd | QSPI_WR_SNGL, qspi->dc, *txbuf);
+               dra7xxx_writel(qspi, QSPI_WC_INT_EN, QSPI_INTR_ENABLE_SET_REG);
you should enable the interrupt as the last step. Also, why aren't you
using frame interrupt ?

+               dra7xxx_writel_data(qspi, *txbuf++, QSPI_SPI_DATA_REG, wlen);
+               dra7xxx_writel(qspi, qspi->dc, QSPI_SPI_DC_REG);
+               dra7xxx_writel(qspi, qspi->cmd | QSPI_WR_SNGL,
+                       QSPI_SPI_CMD_REG);
+               wait_for_completion(&qspi->word_complete);
+       }
+
+       return 0;
+}
+
+static int qspi_read_msg(struct dra7xxx_qspi *qspi, struct spi_transfer *t)
+{
+       u8 *rxbuf;
+       int wlen, count;
+
+       count = t->len;
+       rxbuf = t->rx_buf;
+       wlen = t->bits_per_word;
+
+       while (count--) {
+               dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n",
+                       qspi->cmd | QSPI_RD_SNGL, qspi->dc);
+               dra7xxx_writel(qspi, QSPI_WC_INT_EN, QSPI_INTR_ENABLE_SET_REG);
ditto

+               dra7xxx_writel(qspi, qspi->dc, QSPI_SPI_DC_REG);
+               dra7xxx_writel(qspi, qspi->cmd | QSPI_RD_SNGL,
+                       QSPI_SPI_CMD_REG);
+               wait_for_completion(&qspi->word_complete);
+               *rxbuf++ = dra7xxx_readl_data(qspi, QSPI_SPI_DATA_REG, wlen);
+               dev_dbg(qspi->dev, "rx done, read %02x\n", *(rxbuf-1));
+       }
+
+       return 0;
+}
+
+static int qspi_transfer_msg(struct dra7xxx_qspi *qspi, struct spi_transfer *t)
+{
+       if (t->tx_buf)
+               qspi_write_msg(qspi, t);
+       if (t->rx_buf)
+               qspi_read_msg(qspi, t);
+
+       return 0;
+}
+
+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 frame_length;
+
+       /* setup device control reg */
+       qspi->dc = 0;
+
+       if (spi->mode&  SPI_CPHA)
+               qspi->dc |= QSPI_CKPHA(spi->chip_select);
+       if (spi->mode&  SPI_CPOL)
+               qspi->dc |= QSPI_CKPOL(spi->chip_select);
+       if (spi->mode&  SPI_CS_HIGH)
+               qspi->dc |= QSPI_CSPOL(spi->chip_select);
+
+       frame_length = DIV_ROUND_UP(m->frame_length * spi->bits_per_word,
why this multiplication ? Frame is not counted in bits but in number of
words. Which means that m->framelength / spi->bits_per_word should be
enough.

Also, this actually brings up a mistake I made, if I read the TRM
correclty this time, frame length is nothing but the t->len which
renders patch 1 in this series unnecessary, my mistake.

+                               spi->bits_per_word);
+
+       frame_length = clamp(frame_length, 0, QSPI_FRAME_MAX);
+
+       /* setup command reg */
+       qspi->cmd = 0;
+       qspi->cmd |= QSPI_EN_CS(spi->chip_select);
+       qspi->cmd |= QSPI_FLEN(frame_length);
right, right, so far so good...

+       list_for_each_entry(t,&m->transfers, transfer_list) {
+               qspi->cmd |= QSPI_WLEN(t->bits_per_word);
sure about this ? according to TRM a write of 0 means 1 bit, 1, means 2
bits, 2 means 3 bits, etc... So this should be t->bits_per_word - 1.

+               qspi->cmd |= QSPI_WC_CMD_INT_EN;
... but why are you still interrupting on every word ????

as I said before, we want to interrupt on every frame. one spi_transfer
is one frame, if that frame has a length of 1MiB, I want to be
interrupted after 1MiB.

+               qspi_transfer_msg(qspi, t);
+               m->actual_length += t->len;
+
+               if (list_is_last(&t->transfer_list,&m->transfers))
+                       goto out;
+       }
+
+out:
+       m->status = status;
+       spi_finalize_current_message(master);
+
+       dra7xxx_writel(qspi, qspi->cmd | QSPI_INVAL, QSPI_SPI_CMD_REG);
+
+       return status;
+}
+
+static irqreturn_t dra7xxx_qspi_isr(int irq, void *dev_id)
+{
+       struct dra7xxx_qspi *qspi = dev_id;
+       u16 mask, stat;
+
+       irqreturn_t ret = IRQ_HANDLED;
+
+       spin_lock(&qspi->lock);
+
+       stat = dra7xxx_readl(qspi, QSPI_SPI_STATUS_REG);
+       mask = dra7xxx_readl(qspi, QSPI_SPI_CMD_REG);
+
+       if ((stat&  QSPI_WC)&&  (mask&  QSPI_WC_CMD_INT_EN))
this is wrong, everytime you want to handle another IRQ bit, you will
have to update this line.

        if (stat&  mask)

sounds like it's enough


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