From d294948c2ce4e1c85f452154469752cc9b8e876d Mon Sep 17 00:00:00 2001
From: Robert Jarzmik <robert.jarzmik@free.fr>
Date: Sat, 8 Aug 2009 23:07:22 +0200
Subject: [PATCH] [ARM] pxa/dma: add debugfs entries
Add some debug information for PXA DMA :
- descriptors queued
- channels state
- global state
--
Since V1: reverted to old register access (no more dma_readl() or dma_writel()).
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
---
arch/arm/plat-pxa/dma.c | 249 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 248 insertions(+), 1 deletion(-)
diff --git a/arch/arm/plat-pxa/dma.c b/arch/arm/plat-pxa/dma.c
index 56b51cf0718b..2975798d411f 100644
--- a/arch/arm/plat-pxa/dma.c
+++ b/arch/arm/plat-pxa/dma.c
@@ -17,22 +17,266 @@
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
+#include <linux/dma-mapping.h>
#include <asm/system.h>
#include <asm/irq.h>
+#include <asm/memory.h>
#include <mach/hardware.h>
#include <mach/dma.h>
+#define DMA_DEBUG_NAME "pxa_dma"
+#define DMA_MAX_REQUESTERS 64
+
struct dma_channel {
char *name;
pxa_dma_prio prio;
void (*irq_handler)(int, void *);
void *data;
+ spinlock_t lock;
};
static struct dma_channel *dma_channels;
static int num_dma_channels;
+/*
+ * Debug fs
+ */
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/seq_file.h>
+
+static struct dentry *dbgfs_root, *dbgfs_state, **dbgfs_chan;
+
+static int dbg_show_requester_chan(struct seq_file *s, void *p)
+{
+ int pos = 0;
+ int chan = (int)s->private;
+ int i;
+ u32 drcmr;
+
+ pos += seq_printf(s, "DMA channel %d requesters list :\n", chan);
+ for (i = 0; i < DMA_MAX_REQUESTERS; i++) {
+ drcmr = DRCMR(i);
+ if ((drcmr & DRCMR_CHLNUM) == chan)
+ pos += seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
+ !!(drcmr & DRCMR_MAPVLD));
+ }
+ return pos;
+}
+
+static inline int dbg_burst_from_dcmd(u32 dcmd)
+{
+ int burst = (dcmd >> 16) & 0x3;
+
+ return burst ? 4 << burst : 0;
+}
+
+static int is_phys_valid(unsigned long addr)
+{
+ return pfn_valid(__phys_to_pfn(addr));
+}
+
+#define DCSR_STR(flag) (dcsr & DCSR_##flag ? #flag" " : "")
+#define DCMD_STR(flag) (dcmd & DCMD_##flag ? #flag" " : "")
+
+static int dbg_show_descriptors(struct seq_file *s, void *p)
+{
+ int pos = 0;
+ int chan = (int)s->private;
+ int i, max_show = 20, burst, width;
+ u32 dcmd;
+ unsigned long phys_desc;
+ struct pxa_dma_desc *desc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dma_channels[chan].lock, flags);
+ phys_desc = DDADR(chan);
+
+ pos += seq_printf(s, "DMA channel %d descriptors :\n", chan);
+ pos += seq_printf(s, "[%03d] First descriptor unknown\n", 0);
+ for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) {
+ desc = phys_to_virt(phys_desc);
+ dcmd = desc->dcmd;
+ burst = dbg_burst_from_dcmd(dcmd);
+ width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
+
+ pos += seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n",
+ i, phys_desc, desc);
+ pos += seq_printf(s, "\tDDADR = %08x\n", desc->ddadr);
+ pos += seq_printf(s, "\tDSADR = %08x\n", desc->dsadr);
+ pos += seq_printf(s, "\tDTADR = %08x\n", desc->dtadr);
+ pos += seq_printf(s, "\tDCMD = %08x (%s%s%s%s%s%s%sburst=%d"
+ " width=%d len=%d)\n",
+ dcmd,
+ DCMD_STR(INCSRCADDR), DCMD_STR(INCTRGADDR),
+ DCMD_STR(FLOWSRC), DCMD_STR(FLOWTRG),
+ DCMD_STR(STARTIRQEN), DCMD_STR(ENDIRQEN),
+ DCMD_STR(ENDIAN), burst, width,
+ dcmd & DCMD_LENGTH);
+ phys_desc = desc->ddadr;
+ }
+ if (i == max_show)
+ pos += seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n",
+ i, phys_desc);
+ else
+ pos += seq_printf(s, "[%03d] Desc at %08lx is %s\n",
+ i, phys_desc, phys_desc == DDADR_STOP ?
+ "DDADR_STOP" : "invalid");
+
+ spin_unlock_irqrestore(&dma_channels[chan].lock, flags);
+ return pos;
+}
+
+static int dbg_show_chan_state(struct seq_file *s, void *p)
+{
+ int pos = 0;
+ int chan = (int)s->private;
+ u32 dcsr, dcmd;
+ int burst, width;
+ static char *str_prio[] = { "high", "normal", "low" };
+
+ dcsr = DCSR(chan);
+ dcmd = DCMD(chan);
+ burst = dbg_burst_from_dcmd(dcmd);
+ width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
+
+ pos += seq_printf(s, "DMA channel %d\n", chan);
+ pos += seq_printf(s, "\tPriority : %s\n",
+ str_prio[dma_channels[chan].prio]);
+ pos += seq_printf(s, "\tUnaligned transfer bit: %s\n",
+ DALGN & (1 << chan) ? "yes" : "no");
+ pos += seq_printf(s, "\tDCSR = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
+ dcsr, DCSR_STR(RUN), DCSR_STR(NODESC),
+ DCSR_STR(STOPIRQEN), DCSR_STR(EORIRQEN),
+ DCSR_STR(EORJMPEN), DCSR_STR(EORSTOPEN),
+ DCSR_STR(SETCMPST), DCSR_STR(CLRCMPST),
+ DCSR_STR(CMPST), DCSR_STR(EORINTR), DCSR_STR(REQPEND),
+ DCSR_STR(STOPSTATE), DCSR_STR(ENDINTR),
+ DCSR_STR(STARTINTR), DCSR_STR(BUSERR));
+
+ pos += seq_printf(s, "\tDCMD = %08x (%s%s%s%s%s%s%sburst=%d width=%d"
+ " len=%d)\n",
+ dcmd,
+ DCMD_STR(INCSRCADDR), DCMD_STR(INCTRGADDR),
+ DCMD_STR(FLOWSRC), DCMD_STR(FLOWTRG),
+ DCMD_STR(STARTIRQEN), DCMD_STR(ENDIRQEN),
+ DCMD_STR(ENDIAN), burst, width, dcmd & DCMD_LENGTH);
+ pos += seq_printf(s, "\tDSADR = %08x\n", DSADR(chan));
+ pos += seq_printf(s, "\tDTADR = %08x\n", DTADR(chan));
+ pos += seq_printf(s, "\tDDADR = %08x\n", DDADR(chan));
+ return pos;
+}
+
+static int dbg_show_state(struct seq_file *s, void *p)
+{
+ int pos = 0;
+
+ /* basic device status */
+ pos += seq_printf(s, "DMA engine status\n");
+ pos += seq_printf(s, "\tChannel number: %d\n", num_dma_channels);
+
+ return pos;
+}
+
+#define DBGFS_FUNC_DECL(name) \
+static int dbg_open_##name(struct inode *inode, struct file *file) \
+{ \
+ return single_open(file, dbg_show_##name, inode->i_private); \
+} \
+static const struct file_operations dbg_fops_##name = { \
+ .owner = THIS_MODULE, \
+ .open = dbg_open_##name, \
+ .llseek = seq_lseek, \
+ .read = seq_read, \
+ .release = single_release, \
+}
+
+DBGFS_FUNC_DECL(state);
+DBGFS_FUNC_DECL(chan_state);
+DBGFS_FUNC_DECL(descriptors);
+DBGFS_FUNC_DECL(requester_chan);
+
+static struct dentry *pxa_dma_dbg_alloc_chan(int ch, struct dentry *chandir)
+{
+ char chan_name[11];
+ struct dentry *chan, *chan_state = NULL, *chan_descr = NULL;
+ struct dentry *chan_reqs = NULL;
+ void *dt;
+
+ scnprintf(chan_name, sizeof(chan_name), "%d", ch);
+ chan = debugfs_create_dir(chan_name, chandir);
+ dt = (void *)ch;
+
+ if (chan)
+ chan_state = debugfs_create_file("state", 0400, chan, dt,
+ &dbg_fops_chan_state);
+ if (chan_state)
+ chan_descr = debugfs_create_file("descriptors", 0400, chan, dt,
+ &dbg_fops_descriptors);
+ if (chan_descr)
+ chan_reqs = debugfs_create_file("requesters", 0400, chan, dt,
+ &dbg_fops_requester_chan);
+ if (!chan_reqs)
+ goto err_state;
+
+ return chan;
+
+err_state:
+ debugfs_remove_recursive(chan);
+ return NULL;
+}
+
+static void pxa_dma_init_debugfs(void)
+{
+ int i;
+ struct dentry *chandir;
+
+ dbgfs_root = debugfs_create_dir(DMA_DEBUG_NAME, NULL);
+ if (IS_ERR(dbgfs_root) || !dbgfs_root)
+ goto err_root;
+
+ dbgfs_state = debugfs_create_file("state", 0400, dbgfs_root, NULL,
+ &dbg_fops_state);
+ if (!dbgfs_state)
+ goto err_state;
+
+ dbgfs_chan = kmalloc(sizeof(*dbgfs_state) * num_dma_channels,
+ GFP_KERNEL);
+ if (!dbgfs_state)
+ goto err_alloc;
+
+ chandir = debugfs_create_dir("channels", dbgfs_root);
+ if (!chandir)
+ goto err_chandir;
+
+ for (i = 0; i < num_dma_channels; i++) {
+ dbgfs_chan[i] = pxa_dma_dbg_alloc_chan(i, chandir);
+ if (!dbgfs_chan[i])
+ goto err_chans;
+ }
+
+ return;
+err_chans:
+err_chandir:
+ kfree(dbgfs_chan);
+err_alloc:
+err_state:
+ debugfs_remove_recursive(dbgfs_root);
+err_root:
+ pr_err("pxa_dma: debugfs is not available\n");
+}
+
+static void __exit pxa_dma_cleanup_debugfs(void)
+{
+ debugfs_remove_recursive(dbgfs_root);
+}
+#else
+static inline void pxa_dma_init_debugfs(void) {}
+static inline void pxa_dma_cleanup_debugfs(void) {}
+#endif
+
int pxa_request_dma (char *name, pxa_dma_prio prio,
void (*irq_handler)(int, void *),
void *data)
@@ -130,6 +374,7 @@ int __init pxa_init_dma(int irq, int num_ch)
for (i = 0; i < num_ch; i++) {
DCSR(i) = 0;
dma_channels[i].prio = min((i & 0xf) >> 2, DMA_PRIO_LOW);
+ spin_lock_init(&dma_channels[i].lock);
}
ret = request_irq(irq, dma_irq_handler, IRQF_DISABLED, "DMA", NULL);
@@ -138,7 +383,9 @@ int __init pxa_init_dma(int irq, int num_ch)
kfree(dma_channels);
return ret;
}
-
num_dma_channels = num_ch;
+
+ pxa_dma_init_debugfs();
+
return 0;
}
--
2.34.1