[PATCH v5 15/16] spi: dw: Use regset32 DebugFS method to create regdump file

From: Serge Semin
Date: Fri May 29 2020 - 00:00:35 EST


DebugFS kernel interface provides a dedicated method to create the
registers dump file. Use it instead of creating a generic DebugFS
file with manually written read callback function.

Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Georgy Vlasov <Georgy.Vlasov@xxxxxxxxxxxxxxxxxxxx>
Cc: Ramil Zaripov <Ramil.Zaripov@xxxxxxxxxxxxxxxxxxxx>
Cc: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Feng Tang <feng.tang@xxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx

---

Changelog v3:
- Add commas in the debugfs_reg32 structure initializer and after the last
item of the array dw_spi_dbgfs_regs.
---
drivers/spi/spi-dw-core.c | 86 ++++++++++++---------------------------
drivers/spi/spi-dw.h | 2 +
2 files changed, 28 insertions(+), 60 deletions(-)

diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c
index 4d1849699a12..323c66c5db50 100644
--- a/drivers/spi/spi-dw-core.c
+++ b/drivers/spi/spi-dw-core.c
@@ -29,66 +29,29 @@ struct chip_data {
};

#ifdef CONFIG_DEBUG_FS
-#define SPI_REGS_BUFSIZE 1024
-static ssize_t dw_spi_show_regs(struct file *file, char __user *user_buf,
- size_t count, loff_t *ppos)
-{
- struct dw_spi *dws = file->private_data;
- char *buf;
- u32 len = 0;
- ssize_t ret;
-
- buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
- if (!buf)
- return 0;
-
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "%s registers:\n", dev_name(&dws->master->dev));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "=================================\n");
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "CTRLR0: \t0x%08x\n", dw_readl(dws, DW_SPI_CTRLR0));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "CTRLR1: \t0x%08x\n", dw_readl(dws, DW_SPI_CTRLR1));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "SSIENR: \t0x%08x\n", dw_readl(dws, DW_SPI_SSIENR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "SER: \t\t0x%08x\n", dw_readl(dws, DW_SPI_SER));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "BAUDR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_BAUDR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "TXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_TXFTLR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "RXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_RXFTLR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "TXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_TXFLR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "RXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_RXFLR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "SR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_SR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "IMR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_IMR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "ISR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_ISR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "DMACR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_DMACR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "DMATDLR: \t0x%08x\n", dw_readl(dws, DW_SPI_DMATDLR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "DMARDLR: \t0x%08x\n", dw_readl(dws, DW_SPI_DMARDLR));
- len += scnprintf(buf + len, SPI_REGS_BUFSIZE - len,
- "=================================\n");
-
- ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
- kfree(buf);
- return ret;
+
+#define DW_SPI_DBGFS_REG(_name, _off) \
+{ \
+ .name = _name, \
+ .offset = _off, \
}

-static const struct file_operations dw_spi_regs_ops = {
- .owner = THIS_MODULE,
- .open = simple_open,
- .read = dw_spi_show_regs,
- .llseek = default_llseek,
+static const struct debugfs_reg32 dw_spi_dbgfs_regs[] = {
+ DW_SPI_DBGFS_REG("CTRLR0", DW_SPI_CTRLR0),
+ DW_SPI_DBGFS_REG("CTRLR1", DW_SPI_CTRLR1),
+ DW_SPI_DBGFS_REG("SSIENR", DW_SPI_SSIENR),
+ DW_SPI_DBGFS_REG("SER", DW_SPI_SER),
+ DW_SPI_DBGFS_REG("BAUDR", DW_SPI_BAUDR),
+ DW_SPI_DBGFS_REG("TXFTLR", DW_SPI_TXFTLR),
+ DW_SPI_DBGFS_REG("RXFTLR", DW_SPI_RXFTLR),
+ DW_SPI_DBGFS_REG("TXFLR", DW_SPI_TXFLR),
+ DW_SPI_DBGFS_REG("RXFLR", DW_SPI_RXFLR),
+ DW_SPI_DBGFS_REG("SR", DW_SPI_SR),
+ DW_SPI_DBGFS_REG("IMR", DW_SPI_IMR),
+ DW_SPI_DBGFS_REG("ISR", DW_SPI_ISR),
+ DW_SPI_DBGFS_REG("DMACR", DW_SPI_DMACR),
+ DW_SPI_DBGFS_REG("DMATDLR", DW_SPI_DMATDLR),
+ DW_SPI_DBGFS_REG("DMARDLR", DW_SPI_DMARDLR),
};

static int dw_spi_debugfs_init(struct dw_spi *dws)
@@ -100,8 +63,11 @@ static int dw_spi_debugfs_init(struct dw_spi *dws)
if (!dws->debugfs)
return -ENOMEM;

- debugfs_create_file("registers", S_IFREG | S_IRUGO,
- dws->debugfs, (void *)dws, &dw_spi_regs_ops);
+ dws->regset.regs = dw_spi_dbgfs_regs;
+ dws->regset.nregs = ARRAY_SIZE(dw_spi_dbgfs_regs);
+ dws->regset.base = dws->regs;
+ debugfs_create_regset32("registers", 0400, dws->debugfs, &dws->regset);
+
return 0;
}

diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index 0b2cd7994513..151ba316619e 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -3,6 +3,7 @@
#define DW_SPI_HEADER_H

#include <linux/completion.h>
+#include <linux/debugfs.h>
#include <linux/irqreturn.h>
#include <linux/io.h>
#include <linux/scatterlist.h>
@@ -152,6 +153,7 @@ struct dw_spi {

#ifdef CONFIG_DEBUG_FS
struct dentry *debugfs;
+ struct debugfs_regset32 regset;
#endif
};

--
2.26.2