[PATCH linux v2 3/3] spi: aspeed: Introduce a "ranges" debugfs file

From: Cédric Le Goater
Date: Mon Oct 17 2022 - 05:18:27 EST


This dumps the mapping windows, or decoding ranges, of all devices
possibly attached of the controller. To be noted that a top level
"spi" debugfs directory is created to hold the intermediate directory
of the driver instance.

Cc: Chin-Ting Kuo <chin-ting_kuo@xxxxxxxxxxxxxx>
Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>
---
drivers/spi/spi-aspeed-smc.c | 66 +++++++++++++++++++++++++++++++++++-
1 file changed, 65 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-aspeed-smc.c b/drivers/spi/spi-aspeed-smc.c
index 75e1d08bbd00..a79e5cc8ac5b 100644
--- a/drivers/spi/spi-aspeed-smc.c
+++ b/drivers/spi/spi-aspeed-smc.c
@@ -7,6 +7,7 @@
*/

#include <linux/clk.h>
+#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
@@ -102,6 +103,9 @@ struct aspeed_spi {
u32 clk_freq;

struct aspeed_spi_chip chips[ASPEED_SPI_MAX_NUM_CS];
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+ struct dentry *debugfs;
+#endif
};

static u32 aspeed_spi_get_io_mode(const struct spi_mem_op *op)
@@ -716,6 +720,65 @@ static void aspeed_spi_enable(struct aspeed_spi *aspi, bool enable)
aspeed_spi_chip_enable(aspi, cs, enable);
}

+#if IS_ENABLED(CONFIG_DEBUG_FS)
+static int aspeed_spi_ranges_debug_show(struct seq_file *m, void *private)
+{
+ struct aspeed_spi *aspi = m->private;
+ struct aspeed_spi_window windows[ASPEED_SPI_MAX_NUM_CS] = { 0 };
+ u32 cs;
+
+ if (aspi->data == &ast2400_spi_data)
+ return 0;
+
+ aspeed_spi_get_windows(aspi, windows);
+
+ seq_puts(m, " offset size register\n");
+ for (cs = 0; cs < aspi->data->max_cs; cs++) {
+ if (!windows[cs].reg)
+ seq_printf(m, "CE%d: disabled\n", cs);
+ else
+ seq_printf(m, "CE%d: 0x%.8x 0x%.8x 0x%x\n", cs,
+ windows[cs].offset, windows[cs].size,
+ windows[cs].reg);
+ }
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(aspeed_spi_ranges_debug);
+
+static int aspeed_spi_debugfs_init(struct spi_controller *ctlr)
+{
+ struct aspeed_spi *aspi = spi_controller_get_devdata(ctlr);
+ struct dentry *rootdir = NULL;
+
+ rootdir = debugfs_lookup("spi", NULL);
+ if (!rootdir)
+ rootdir = debugfs_create_dir("spi", NULL);
+
+ aspi->debugfs = debugfs_create_dir(dev_name(&ctlr->dev), rootdir);
+ if (!aspi->debugfs)
+ return -ENOMEM;
+
+ debugfs_create_file("ranges", 0444, aspi->debugfs, (void *)aspi,
+ &aspeed_spi_ranges_debug_fops);
+ return 0;
+}
+
+static void aspeed_spi_debugfs_remove(struct aspeed_spi *aspi)
+{
+ debugfs_remove_recursive(aspi->debugfs);
+}
+
+#else
+static inline int aspeed_spi_debugfs_init(struct spi_controller *ctlr)
+{
+ return 0;
+}
+
+static inline void aspeed_spi_debugfs_remove(struct aspeed_spi *aspi)
+{
+}
+#endif /* IS_ENABLED(CONFIG_DEBUG_FS) */
+
static int aspeed_spi_chip_read_ranges(struct device_node *node, struct aspeed_spi *aspi)
{
const char *range_prop = "ranges";
@@ -845,7 +908,7 @@ static int aspeed_spi_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "spi_register_controller failed\n");
goto disable_clk;
}
- return 0;
+ return aspeed_spi_debugfs_init(ctlr);

disable_clk:
clk_disable_unprepare(aspi->clk);
@@ -856,6 +919,7 @@ static int aspeed_spi_remove(struct platform_device *pdev)
{
struct aspeed_spi *aspi = platform_get_drvdata(pdev);

+ aspeed_spi_debugfs_remove(aspi);
aspeed_spi_enable(aspi, false);
clk_disable_unprepare(aspi->clk);
return 0;
--
2.37.3