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

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Hi,


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;
+}

I would recommend to drop this function.

The objective of this is to retrieve spi_master

The call sequence is probe() => geni_init() => get_spi_master()

probe() already has access to spi_master

why not simply pass it down to geni_init()?

Thank you.

+
+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"))
+		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);



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