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

From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
To: Praveen Talari <quic_ptalari@quicinc.com>
Cc: agross@kernel.org, andersson@kernel.org,
	konrad.dybcio@linaro.org, broonie@kernel.org,
	linux-arm-msm@vger.kernel.org, linux-spi@vger.kernel.org,
	linux-kernel@vger.kernel.org, quic_msavaliy@quicinc.com,
	quic_vtanuku@quicinc.com, quic_vnivarth@quicinc.com,
	quic_arandive@quicinc.com
Subject: Re: [PATCH v4 2/2] spi: spi-geni-qcom: Add SPI Device mode support for GENI based QuPv3
Date: Thu, 6 Jul 2023 09:39:56 +0300	[thread overview]
Message-ID: <CAA8EJprU3FhEWodw2rfFiYkw3rg_WaxqZOOQOt=mcp3xfsoJUw@mail.gmail.com> (raw)
In-Reply-To: <20230706051024.15422-3-quic_ptalari@quicinc.com>

On Thu, 6 Jul 2023 at 08:12, Praveen Talari <quic_ptalari@quicinc.com> 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@quicinc.com>
> ---
> 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.

> +
> +       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.

> +               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

> +       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
>

-- 
With best wishes
Dmitry