Re: [PATCH v4 2/2] spi: spi-geni-qcom: Add SPI Device mode support for GENI based QuPv3

[Praveen Talari <quic_ptalari@xxxxxxxxxxx>]

Hi,

On 7/6/2023 12:09 PM, Dmitry Baryshkov wrote:
> On Thu, 6 Jul 2023 at 08:12, Praveen Talari <quic_ptalari@xxxxxxxxxxx> wrote:
> > Currently spi geni driver supports only master mode operation.
> >
> > Add spi device mode support to GENI based QuPv3.
> >
> > Signed-off-by: Praveen Talari <quic_ptalari@xxxxxxxxxxx>
> > ---
> > v3 -> v4:
> > - Used existing property spi-slave.
> >
> > v2 -> v3:
> > - modified commit message to use device mode instead of slave mode
> >
> > v1 -> v2
> > - modified the commit message
> > - added the code changes for code comments
> > ---
> >   drivers/spi/spi-geni-qcom.c | 57 +++++++++++++++++++++++++++++++++----
> >   1 file changed, 51 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
> > index 206cc04bb1ed..4ec4fdee06b5 100644
> > --- a/drivers/spi/spi-geni-qcom.c
> > +++ b/drivers/spi/spi-geni-qcom.c
> > @@ -12,6 +12,7 @@
> >   #include <linux/platform_device.h>
> >   #include <linux/pm_opp.h>
> >   #include <linux/pm_runtime.h>
> > +#include <linux/property.h>
> >   #include <linux/soc/qcom/geni-se.h>
> >   #include <linux/spi/spi.h>
> >   #include <linux/spinlock.h>
> > @@ -52,6 +53,9 @@
> >   #define SPI_CS_CLK_DELAY_MSK           GENMASK(19, 10)
> >   #define SPI_CS_CLK_DELAY_SHFT          10
> >
> > +#define SE_SPI_SLAVE_EN                                (0x2BC)
> > +#define SPI_SLAVE_EN                           BIT(0)
> > +
> >   /* M_CMD OP codes for SPI */
> >   #define SPI_TX_ONLY            1
> >   #define SPI_RX_ONLY            2
> > @@ -99,6 +103,24 @@ struct spi_geni_master {
> >          int cur_xfer_mode;
> >   };
> >
> > +static struct spi_master *get_spi_master(struct device *dev)
> > +{
> > +       struct platform_device *pdev = to_platform_device(dev);
> > +       struct spi_master *spi = platform_get_drvdata(pdev);
> You can use dev_get_drvdata() directly, without going through platform_device.
Done
> > +
> > +       return spi;
> > +}
> > +
> > +static void spi_slv_setup(struct spi_geni_master *mas)
> > +{
> > +       struct geni_se *se = &mas->se;
> > +
> > +       writel(SPI_SLAVE_EN, se->base + SE_SPI_SLAVE_EN);
> > +       writel(GENI_IO_MUX_0_EN, se->base + GENI_OUTPUT_CTRL);
> > +       writel(START_TRIGGER, se->base + SE_GENI_CFG_SEQ_START);
> > +       dev_dbg(mas->dev, "spi slave setup done\n");
> > +}
> > +
> >   static int get_spi_clk_cfg(unsigned int speed_hz,
> >                          struct spi_geni_master *mas,
> >                          unsigned int *clk_idx,
> > @@ -140,12 +162,18 @@ static void handle_se_timeout(struct spi_master *spi,
> >          const struct spi_transfer *xfer;
> >
> >          spin_lock_irq(&mas->lock);
> > -       reinit_completion(&mas->cancel_done);
> >          if (mas->cur_xfer_mode == GENI_SE_FIFO)
> >                  writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
> >
> >          xfer = mas->cur_xfer;
> >          mas->cur_xfer = NULL;
> > +
> > +       if (spi->slave) {
> A comment here would be nice.
Done
> > +               spin_unlock_irq(&mas->lock);
> > +               goto unmap_if_dma;
> > +       }
> > +
> > +       reinit_completion(&mas->cancel_done);
> >          geni_se_cancel_m_cmd(se);
> >          spin_unlock_irq(&mas->lock);
> >
> > @@ -542,6 +570,10 @@ static bool geni_can_dma(struct spi_controller *ctlr,
> >          if (mas->cur_xfer_mode == GENI_GPI_DMA)
> >                  return true;
> >
> > +       /* Set DMA mode for SPI slave. */
> SE DMA mode
Done
> > +       if (ctlr->slave)
> > +               return true;
> > +
> >          len = get_xfer_len_in_words(xfer, mas);
> >          fifo_size = mas->tx_fifo_depth * mas->fifo_width_bits / mas->cur_bits_per_word;
> >
> > @@ -619,6 +651,7 @@ static void spi_geni_release_dma_chan(struct spi_geni_master *mas)
> >
> >   static int spi_geni_init(struct spi_geni_master *mas)
> >   {
> > +       struct spi_master *spi = get_spi_master(mas->dev);
> >          struct geni_se *se = &mas->se;
> >          unsigned int proto, major, minor, ver;
> >          u32 spi_tx_cfg, fifo_disable;
> > @@ -627,7 +660,14 @@ static int spi_geni_init(struct spi_geni_master *mas)
> >          pm_runtime_get_sync(mas->dev);
> >
> >          proto = geni_se_read_proto(se);
> > -       if (proto != GENI_SE_SPI) {
> > +
> > +       if (spi->slave) {
> > +               if (proto != GENI_SE_SPI_SLAVE) {
> > +                       dev_err(mas->dev, "Invalid proto %d\n", proto);
> > +                       goto out_pm;
> > +               }
> > +               spi_slv_setup(mas);
> > +       } else if (proto != GENI_SE_SPI) {
> >                  dev_err(mas->dev, "Invalid proto %d\n", proto);
> >                  goto out_pm;
> >          }
> > @@ -677,9 +717,11 @@ static int spi_geni_init(struct spi_geni_master *mas)
> >          }
> >
> >          /* We always control CS manually */
> > -       spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
> > -       spi_tx_cfg &= ~CS_TOGGLE;
> > -       writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
> > +       if (!spi->slave) {
> > +               spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
> > +               spi_tx_cfg &= ~CS_TOGGLE;
> > +               writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
> > +       }
> >
> >   out_pm:
> >          pm_runtime_put(mas->dev);
> > @@ -1072,6 +1114,9 @@ static int spi_geni_probe(struct platform_device *pdev)
> >          pm_runtime_set_autosuspend_delay(&pdev->dev, 250);
> >          pm_runtime_enable(dev);
> >
> > +       if (device_property_read_bool(&pdev->dev, "spi-slave"))
> > +               spi->slave = true;
> > +
> >          ret = geni_icc_get(&mas->se, NULL);
> >          if (ret)
> >                  goto spi_geni_probe_runtime_disable;
> > @@ -1092,7 +1137,7 @@ static int spi_geni_probe(struct platform_device *pdev)
> >           * for dma (gsi) mode, the gsi will set cs based on params passed in
> >           * TRE
> >           */
> > -       if (mas->cur_xfer_mode == GENI_SE_FIFO)
> > +       if (!spi->slave && mas->cur_xfer_mode == GENI_SE_FIFO)
> >                  spi->set_cs = spi_geni_set_cs;
> >
> >          ret = request_irq(mas->irq, geni_spi_isr, 0, dev_name(dev), spi);
> > --
> > 2.17.1