spi: bcm2835aux: add driver stats to debugfs

To estimate efficiency add statistics on transfer types
(polling and interrupt) used to debugfs.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c
index 056a8e2..1a11b91 100644 (file)
--- a/drivers/spi/spi-bcm2835aux.c
+++ b/drivers/spi/spi-bcm2835aux.c
@@ -21,6 +21,7 @@
 
 #include <linux/clk.h>
 #include <linux/completion.h>
+#include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
@@ -104,8 +105,52 @@ struct bcm2835aux_spi {
        int tx_len;
        int rx_len;
        int pending;
+
+       u64 count_transfer_polling;
+       u64 count_transfer_irq;
+       u64 count_transfer_irq_after_poll;
+
+       struct dentry *debugfs_dir;
 };
 
+#if defined(CONFIG_DEBUG_FS)
+static void bcm2835aux_debugfs_create(struct bcm2835aux_spi *bs,
+                                     const char *dname)
+{
+       char name[64];
+       struct dentry *dir;
+
+       /* get full name */
+       snprintf(name, sizeof(name), "spi-bcm2835aux-%s", dname);
+
+       /* the base directory */
+       dir = debugfs_create_dir(name, NULL);
+       bs->debugfs_dir = dir;
+
+       /* the counters */
+       debugfs_create_u64("count_transfer_polling", 0444, dir,
+                          &bs->count_transfer_polling);
+       debugfs_create_u64("count_transfer_irq", 0444, dir,
+                          &bs->count_transfer_irq);
+       debugfs_create_u64("count_transfer_irq_after_poll", 0444, dir,
+                          &bs->count_transfer_irq_after_poll);
+}
+
+static void bcm2835aux_debugfs_remove(struct bcm2835aux_spi *bs)
+{
+       debugfs_remove_recursive(bs->debugfs_dir);
+       bs->debugfs_dir = NULL;
+}
+#else
+static void bcm2835aux_debugfs_create(struct bcm2835aux_spi *bs)
+{
+}
+
+static void bcm2835aux_debugfs_remove(struct bcm2835aux_spi *bs)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
 static inline u32 bcm2835aux_rd(struct bcm2835aux_spi *bs, unsigned reg)
 {
        return readl(bs->regs + reg);
@@ -244,6 +289,9 @@ static int bcm2835aux_spi_transfer_one_irq(struct spi_master *master,
 {
        struct bcm2835aux_spi *bs = spi_master_get_devdata(master);
 
+       /* update statistics */
+       bs->count_transfer_irq++;
+
        /* fill in registers and fifos before enabling interrupts */
        bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL1, bs->cntl[1]);
        bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL0, bs->cntl[0]);
@@ -267,6 +315,9 @@ static int bcm2835aux_spi_transfer_one_poll(struct spi_master *master,
        struct bcm2835aux_spi *bs = spi_master_get_devdata(master);
        unsigned long timeout;
 
+       /* update statistics */
+       bs->count_transfer_polling++;
+
        /* configure spi */
        bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL1, bs->cntl[1]);
        bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL0, bs->cntl[0]);
@@ -287,6 +338,7 @@ static int bcm2835aux_spi_transfer_one_poll(struct spi_master *master,
                                            jiffies - timeout,
                                            bs->tx_len, bs->rx_len);
                        /* forward to interrupt handler */
+                       bs->count_transfer_irq_after_poll++;
                        return __bcm2835aux_spi_transfer_one_irq(master,
                                                               spi, tfr);
                }
@@ -536,6 +588,8 @@ static int bcm2835aux_spi_probe(struct platform_device *pdev)
                goto out_clk_disable;
        }
 
+       bcm2835aux_debugfs_create(bs, dev_name(&pdev->dev));
+
        return 0;
 
 out_clk_disable:
@@ -550,6 +604,8 @@ static int bcm2835aux_spi_remove(struct platform_device *pdev)
        struct spi_master *master = platform_get_drvdata(pdev);
        struct bcm2835aux_spi *bs = spi_master_get_devdata(master);
 
+       bcm2835aux_debugfs_remove(bs);
+
        bcm2835aux_spi_reset_hw(bs);
 
        /* disable the HW block by releasing the clock */