spi: hisi-kunpeng: Add debugfs support

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>
Link: https://lore.kernel.org/r/1622789718-13977-1-git-send-email-f.fangjian@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-hisi-kunpeng.c b/drivers/spi/spi-hisi-kunpeng.c
index 3f986ba..58b823a 100644 (file)
--- 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;