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

From: Praveen Talari
Date: Thu Jun 15 2023 - 03:06:48 EST


Hi

Thank you for review.

On 6/13/2023 1:12 PM, Shazad Hussain wrote:


On 6/13/2023 12:22 PM, Praveen Talari wrote:
Add SPI SLAVE mode support for GENI based QuPv3.

Signed-off-by: Praveen Talari <quic_ptalari@xxxxxxxxxxx>
---
  drivers/spi/spi-geni-qcom.c | 55 +++++++++++++++++++++++++++++++++----
  1 file changed, 49 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
index 206cc04bb1ed..2e3ae29e79e0 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);
+
+    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_info(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) {
+        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);
  @@ -541,6 +569,8 @@ static bool geni_can_dma(struct spi_controller *ctlr,
        if (mas->cur_xfer_mode == GENI_GPI_DMA)
          return true;
+    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 +649,7 @@ 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 +658,14 @@ 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 +715,11 @@ 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 +1112,9 @@ 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, "qcom,slv-ctrl"))

Should we update this property "qcom,slv-ctrl" in device tree bindings
as well !!
Done


+        spi->slave = true;
+
      ret = geni_icc_get(&mas->se, NULL);
      if (ret)
          goto spi_geni_probe_runtime_disable;
@@ -1092,7 +1135,7 @@ 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);

-Shazad