atmel-mci: debugfs support

Create additional files under the host's debugfs directory containing
additional host-specific debug information.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

2 files changed, 191 insertions, 0 deletions

diff --git a/drivers/mmc/host/atmel-mci-regs.h b/drivers/mmc/host/atmel-mci-regs.h
index a9a5657706c6..26bd80e65031 100644
--- a/drivers/mmc/host/atmel-mci-regs.h
+++ b/drivers/mmc/host/atmel-mci-regs.h
@@ -82,6 +82,8 @@
 # define MCI_OVRE               (  1 <<  30)    /* RX Overrun Error */
 # define MCI_UNRE               (  1 <<  31)    /* TX Underrun Error */
 
+#define MCI_REGS_SIZE           0x100
+
 /* Register access macros */
 #define mci_readl(port,reg)                             \
         __raw_readl((port)->regs + MCI_##reg)
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index cce873c5a149..b68381f7bfdd 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -9,6 +9,7 @@
  */
 #include <linux/blkdev.h>
 #include <linux/clk.h>
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
@@ -16,6 +17,8 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/scatterlist.h>
+#include <linux/seq_file.h>
+#include <linux/stat.h>
 
 #include <linux/mmc/host.h>
 
@@ -88,6 +91,188 @@ struct atmel_mci {
 #define atmci_clear_pending(host, event)                        \
         clear_bit(event, &host->pending_events)
 
+/*
+ * The debugfs stuff below is mostly optimized away when
+ * CONFIG_DEBUG_FS is not set.
+ */
+static int atmci_req_show(struct seq_file *s, void *v)
+{
+        struct atmel_mci        *host = s->private;
+        struct mmc_request      *mrq = host->mrq;
+        struct mmc_command      *cmd;
+        struct mmc_command      *stop;
+        struct mmc_data         *data;
+
+        /* Make sure we get a consistent snapshot */
+        spin_lock_irq(&host->mmc->lock);
+
+        if (mrq) {
+                cmd = mrq->cmd;
+                data = mrq->data;
+                stop = mrq->stop;
+
+                if (cmd)
+                        seq_printf(s,
+                                "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
+                                cmd->opcode, cmd->arg, cmd->flags,
+                                cmd->resp[0], cmd->resp[1], cmd->resp[2],
+                                cmd->resp[2], cmd->error);
+                if (data)
+                        seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
+                                data->bytes_xfered, data->blocks,
+                                data->blksz, data->flags, data->error);
+                if (stop)
+                        seq_printf(s,
+                                "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
+                                stop->opcode, stop->arg, stop->flags,
+                                stop->resp[0], stop->resp[1], stop->resp[2],
+                                stop->resp[2], stop->error);
+        }
+
+        spin_unlock_irq(&host->mmc->lock);
+
+        return 0;
+}
+
+static int atmci_req_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, atmci_req_show, inode->i_private);
+}
+
+static const struct file_operations atmci_req_fops = {
+        .owner          = THIS_MODULE,
+        .open           = atmci_req_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static void atmci_show_status_reg(struct seq_file *s,
+                const char *regname, u32 value)
+{
+        static const char       *sr_bit[] = {
+                [0]     = "CMDRDY",
+                [1]     = "RXRDY",
+                [2]     = "TXRDY",
+                [3]     = "BLKE",
+                [4]     = "DTIP",
+                [5]     = "NOTBUSY",
+                [8]     = "SDIOIRQA",
+                [9]     = "SDIOIRQB",
+                [16]    = "RINDE",
+                [17]    = "RDIRE",
+                [18]    = "RCRCE",
+                [19]    = "RENDE",
+                [20]    = "RTOE",
+                [21]    = "DCRCE",
+                [22]    = "DTOE",
+                [30]    = "OVRE",
+                [31]    = "UNRE",
+        };
+        unsigned int            i;
+
+        seq_printf(s, "%s:\t0x%08x", regname, value);
+        for (i = 0; i < ARRAY_SIZE(sr_bit); i++) {
+                if (value & (1 << i)) {
+                        if (sr_bit[i])
+                                seq_printf(s, " %s", sr_bit[i]);
+                        else
+                                seq_puts(s, " UNKNOWN");
+                }
+        }
+        seq_putc(s, '\n');
+}
+
+static int atmci_regs_show(struct seq_file *s, void *v)
+{
+        struct atmel_mci        *host = s->private;
+        u32                     *buf;
+
+        buf = kmalloc(MCI_REGS_SIZE, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
+        /* Grab a more or less consistent snapshot */
+        spin_lock_irq(&host->mmc->lock);
+        memcpy_fromio(buf, host->regs, MCI_REGS_SIZE);
+        spin_unlock_irq(&host->mmc->lock);
+
+        seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
+                        buf[MCI_MR / 4],
+                        buf[MCI_MR / 4] & MCI_MR_RDPROOF ? " RDPROOF" : "",
+                        buf[MCI_MR / 4] & MCI_MR_WRPROOF ? " WRPROOF" : "",
+                        buf[MCI_MR / 4] & 0xff);
+        seq_printf(s, "DTOR:\t0x%08x\n", buf[MCI_DTOR / 4]);
+        seq_printf(s, "SDCR:\t0x%08x\n", buf[MCI_SDCR / 4]);
+        seq_printf(s, "ARGR:\t0x%08x\n", buf[MCI_ARGR / 4]);
+        seq_printf(s, "BLKR:\t0x%08x BCNT=%u BLKLEN=%u\n",
+                        buf[MCI_BLKR / 4],
+                        buf[MCI_BLKR / 4] & 0xffff,
+                        (buf[MCI_BLKR / 4] >> 16) & 0xffff);
+
+        /* Don't read RSPR and RDR; it will consume the data there */
+
+        atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);
+        atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);
+
+        return 0;
+}
+
+static int atmci_regs_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, atmci_regs_show, inode->i_private);
+}
+
+static const struct file_operations atmci_regs_fops = {
+        .owner          = THIS_MODULE,
+        .open           = atmci_regs_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static void atmci_init_debugfs(struct atmel_mci *host)
+{
+        struct mmc_host *mmc;
+        struct dentry   *root;
+        struct dentry   *node;
+        struct resource *res;
+
+        mmc = host->mmc;
+        root = mmc->debugfs_root;
+        if (!root)
+                return;
+
+        node = debugfs_create_file("regs", S_IRUSR, root, host,
+                        &atmci_regs_fops);
+        if (IS_ERR(node))
+                return;
+        if (!node)
+                goto err;
+
+        res = platform_get_resource(host->pdev, IORESOURCE_MEM, 0);
+        node->d_inode->i_size = res->end - res->start + 1;
+
+        node = debugfs_create_file("req", S_IRUSR, root, host, &atmci_req_fops);
+        if (!node)
+                goto err;
+
+        node = debugfs_create_x32("pending_events", S_IRUSR, root,
+                                     (u32 *)&host->pending_events);
+        if (!node)
+                goto err;
+
+        node = debugfs_create_x32("completed_events", S_IRUSR, root,
+                                     (u32 *)&host->completed_events);
+        if (!node)
+                goto err;
+
+        return;
+
+err:
+        dev_err(&host->pdev->dev,
+                "failed to initialize debugfs for controller\n");
+}
 
 static void atmci_enable(struct atmel_mci *host)
 {
@@ -905,6 +1090,8 @@ static int __init atmci_probe(struct platform_device *pdev)
                         "Atmel MCI controller at 0x%08lx irq %d\n",
                         host->mapbase, irq);
 
+        atmci_init_debugfs(host);
+
         return 0;
 
 err_request_irq:
@@ -923,6 +1110,8 @@ static int __exit atmci_remove(struct platform_device *pdev)
         platform_set_drvdata(pdev, NULL);
 
         if (host) {
+                /* Debugfs stuff is cleaned up by mmc core */
+
                 if (host->detect_pin >= 0) {
                         int pin = host->detect_pin;