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Message-ID: <af82e3e0-0e80-72b2-e799-2b558ce119ff@quicinc.com>
Date:   Fri, 7 Jul 2023 10:46:12 +0530
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Subject: Re: [PATCH v4 2/2] spi: spi-geni-qcom: Add SPI Device mode support
 for GENI based QuPv3
Content-Language: en-US
To:     Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
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>
References: <20230706051024.15422-1-quic_ptalari@quicinc.com>
 <20230706051024.15422-3-quic_ptalari@quicinc.com>
 <CAA8EJprU3FhEWodw2rfFiYkw3rg_WaxqZOOQOt=mcp3xfsoJUw@mail.gmail.com>
From:   Praveen Talari <quic_ptalari@quicinc.com>
In-Reply-To: <CAA8EJprU3FhEWodw2rfFiYkw3rg_WaxqZOOQOt=mcp3xfsoJUw@mail.gmail.com>
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Hi,

On 7/6/2023 12:09 PM, Dmitry Baryshkov wrote:
> 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.
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
>>
>