[PATCH] spi: hisi-kunpeng: Add debugfs support

[PATCH] spi: hisi-kunpeng: Add debugfs support

[Jay Fang]

This patch uses debugfs_regset32 interface to create the registers dump
file. Use it instead of creating a generic debugfs file with manually
written read callback function.

With these entries, users can check all the SPI controller registers
during run time.

Signed-off-by: Jay Fang <f.fangjian@huawei.com>
---
 drivers/spi/spi-hisi-kunpeng.c | 51 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-hisi-kunpeng.c b/drivers/spi/spi-hisi-kunpeng.c
index 3f986ba..58b823a 100644
--- a/drivers/spi/spi-hisi-kunpeng.c
+++ b/drivers/spi/spi-hisi-kunpeng.c
@@ -9,6 +9,7 @@
 
 #include <linux/acpi.h>
 #include <linux/bitfield.h>
+#include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
@@ -126,6 +127,7 @@ struct hisi_spi {
 	void __iomem		*regs;
 	int			irq;
 	u32			fifo_len; /* depth of the FIFO buffer */
+	u16			bus_num;
 
 	/* Current message transfer state info */
 	const void		*tx;
@@ -133,8 +135,49 @@ struct hisi_spi {
 	void			*rx;
 	unsigned int		rx_len;
 	u8			n_bytes; /* current is a 1/2/4 bytes op */
+
+	struct dentry *debugfs;
+	struct debugfs_regset32 regset;
+};
+
+#define HISI_SPI_DBGFS_REG(_name, _off)	\
+{					\
+	.name = _name,			\
+	.offset = _off,			\
+}
+
+static const struct debugfs_reg32 hisi_spi_regs[] = {
+	HISI_SPI_DBGFS_REG("CSCR", HISI_SPI_CSCR),
+	HISI_SPI_DBGFS_REG("CR", HISI_SPI_CR),
+	HISI_SPI_DBGFS_REG("ENR", HISI_SPI_ENR),
+	HISI_SPI_DBGFS_REG("FIFOC", HISI_SPI_FIFOC),
+	HISI_SPI_DBGFS_REG("IMR", HISI_SPI_IMR),
+	HISI_SPI_DBGFS_REG("DIN", HISI_SPI_DIN),
+	HISI_SPI_DBGFS_REG("DOUT", HISI_SPI_DOUT),
+	HISI_SPI_DBGFS_REG("SR", HISI_SPI_SR),
+	HISI_SPI_DBGFS_REG("RISR", HISI_SPI_RISR),
+	HISI_SPI_DBGFS_REG("ISR", HISI_SPI_ISR),
+	HISI_SPI_DBGFS_REG("ICR", HISI_SPI_ICR),
+	HISI_SPI_DBGFS_REG("VERSION", HISI_SPI_VERSION),
 };
 
+static int hisi_spi_debugfs_init(struct hisi_spi *hs)
+{
+	char name[32];
+
+	snprintf(name, 32, "hisi_spi%d", hs->bus_num);
+	hs->debugfs = debugfs_create_dir(name, NULL);
+	if (!hs->debugfs)
+		return -ENOMEM;
+
+	hs->regset.regs = hisi_spi_regs;
+	hs->regset.nregs = ARRAY_SIZE(hisi_spi_regs);
+	hs->regset.base = hs->regs;
+	debugfs_create_regset32("registers", 0400, hs->debugfs, &hs->regset);
+
+	return 0;
+}
+
 static u32 hisi_spi_busy(struct hisi_spi *hs)
 {
 	return readl(hs->regs + HISI_SPI_SR) & SR_BUSY;
@@ -424,6 +467,7 @@ static int hisi_spi_probe(struct platform_device *pdev)
 	hs = spi_controller_get_devdata(master);
 	hs->dev = dev;
 	hs->irq = irq;
+	hs->bus_num = pdev->id;
 
 	hs->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(hs->regs))
@@ -446,7 +490,7 @@ static int hisi_spi_probe(struct platform_device *pdev)
 	master->use_gpio_descriptors = true;
 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
-	master->bus_num = pdev->id;
+	master->bus_num = hs->bus_num;
 	master->setup = hisi_spi_setup;
 	master->cleanup = hisi_spi_cleanup;
 	master->transfer_one = hisi_spi_transfer_one;
@@ -462,6 +506,9 @@ static int hisi_spi_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	if (hisi_spi_debugfs_init(hs))
+		dev_info(dev, "failed to create debugfs dir\n");
+
 	ret = spi_register_controller(master);
 	if (ret) {
 		dev_err(dev, "failed to register spi master, ret=%d\n", ret);
@@ -478,7 +525,9 @@ static int hisi_spi_probe(struct platform_device *pdev)
 static int hisi_spi_remove(struct platform_device *pdev)
 {
 	struct spi_controller *master = platform_get_drvdata(pdev);
+	struct hisi_spi *hs = spi_controller_get_devdata(master);
 
+	debugfs_remove_recursive(hs->debugfs);
 	spi_unregister_controller(master);
 
 	return 0;
-- 
2.7.4

Re: [PATCH] spi: hisi-kunpeng: Add debugfs support

[Mark Brown]

On Fri, 4 Jun 2021 14:55:18 +0800, Jay Fang wrote:
> This patch uses debugfs_regset32 interface to create the registers dump
> file. Use it instead of creating a generic debugfs file with manually
> written read callback function.
> 
> With these entries, users can check all the SPI controller registers
> during run time.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: hisi-kunpeng: Add debugfs support
      commit: 2b2142f247ebeef74aaadc1a646261c19627fd7e

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark