[PATCH 10/11] spi: add more debug prints in s3c64xx

[Michal Suchanek]

The SPI NOR transfers mysteriously fail so add more debug prints about
SPI transactions.

Signed-off-by: Michal Suchanek <hramrach at gmail.com>
---
 drivers/spi/spi-s3c64xx.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 2a90705..0574f0e 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -18,6 +18,7 @@
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
 #include <linux/platform_device.h>
@@ -469,6 +470,7 @@ static int wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
 {
 	void __iomem *regs = sdd->regs;
 	unsigned long val;
+	unsigned long start, end;
 	u32 status;
 	int ms;
 
@@ -477,8 +479,20 @@ static int wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
 	ms += 10; /* some tolerance */
 	ms *= 10;
 
+	pr_debug("%s %s %s waiting for %ims transferring %zubytes@%iHz",
+		 __func__, sdd->pdev ? dev_name(&sdd->pdev->dev) : NULL,
+		 dev_name(&sdd->master->dev),
+		 ms, xfer->len, sdd->cur_speed);
+
 	val = msecs_to_jiffies(ms) + 10;
+	start = jiffies;
 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
+	end = jiffies;
+
+	pr_debug("%s %s %s waited %u ms",
+		 __func__, sdd->pdev ? dev_name(&sdd->pdev->dev) : NULL,
+		 dev_name(&sdd->master->dev),
+		 jiffies_to_msecs(end - start));
 
 	/*
 	 * If the previous xfer was completed within timeout, then
@@ -577,6 +591,14 @@ static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
 	void __iomem *regs = sdd->regs;
 	u32 val;
 
+	pr_debug("%s %s %s clk_from_cmu %i src_clk %s mode%s%s bpw %i",
+		 __func__, sdd->pdev ? dev_name(&sdd->pdev->dev) : NULL,
+		 dev_name(&sdd->master->dev), sdd->port_conf->clk_from_cmu,
+		 sdd->src_clk ? __clk_get_name(sdd->src_clk) : NULL,
+		 (sdd->cur_mode & SPI_CPOL) ? " SPI_CPOL" : "",
+		 (sdd->cur_mode & SPI_CPHA) ? " SPI_CPHA" : "",
+		 sdd->cur_bpw);
+
 	/* Disable Clock */
 	if (sdd->port_conf->clk_from_cmu) {
 		clk_disable_unprepare(sdd->src_clk);
@@ -679,6 +701,10 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
 	unsigned long flags;
 	int use_dma;
 
+	pr_debug("%s %s %s %s xfer bpw %i speed %i",
+		 __func__, sdd->pdev ? dev_name(&sdd->pdev->dev) : NULL,
+		 dev_name(&master->dev), dev_name(&spi->dev),
+		 xfer->bits_per_word, xfer->speed_hz);
 	reinit_completion(&sdd->xfer_completion);
 
 	/* Only BPW and Speed may change across transfers */
@@ -697,6 +723,10 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
 	    (sdd->rx_dma.ch && sdd->tx_dma.ch &&
 	     (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1))))
 		use_dma = 1;
+	pr_debug("%s %s %s %s %susing dma",
+		 __func__, sdd->pdev ? dev_name(&sdd->pdev->dev) : NULL,
+		 dev_name(&master->dev), dev_name(&spi->dev),
+		 use_dma ? "" : "not ");
 
 	spin_lock_irqsave(&sdd->lock, flags);
 
-- 
2.1.4