[PATCH] MMC: wbsd update

Updates to the wbsd driver.
                                                                                
* Fix to handle DAT3 card detection.
* Fixed bug which could cause large writes to stall in FIFO mode.
* Plug 'n Play support. In most cases you need ACPI PNP for this to work.
* Uses generic DMA API (ISA dependency removed).

1 files changed, 531 insertions, 185 deletions

diff --git a/drivers/mmc/wbsd.c b/drivers/mmc/wbsd.c
index 39747526c719..b7fbd30b49a0 100644
--- a/drivers/mmc/wbsd.c
+++ b/drivers/mmc/wbsd.c
@@ -28,7 +28,9 @@
 #include <linux/ioport.h>
 #include <linux/device.h>
 #include <linux/interrupt.h>
+#include <linux/dma-mapping.h>
 #include <linux/delay.h>
+#include <linux/pnp.h>
 #include <linux/highmem.h>
 #include <linux/mmc/host.h>
 #include <linux/mmc/protocol.h>
@@ -40,7 +42,7 @@
 #include "wbsd.h"
 
 #define DRIVER_NAME "wbsd"
-#define DRIVER_VERSION "1.1"
+#define DRIVER_VERSION "1.2"
 
 #ifdef CONFIG_MMC_DEBUG
 #define DBG(x...) \
@@ -52,10 +54,6 @@
 #define DBGF(x...)      do { } while (0)
 #endif
 
-static unsigned int io = 0x248;
-static unsigned int irq = 6;
-static int dma = 2;
-
 #ifdef CONFIG_MMC_DEBUG
 void DBG_REG(int reg, u8 value)
 {
@@ -79,28 +77,61 @@ void DBG_REG(int reg, u8 value)
 #endif
 
 /*
+ * Device resources
+ */
+
+#ifdef CONFIG_PNP
+
+static const struct pnp_device_id pnp_dev_table[] = {
+        { "WEC0517", 0 },
+        { "WEC0518", 0 },
+        { "", 0 },
+};
+
+MODULE_DEVICE_TABLE(pnp, pnp_dev_table);
+
+#endif /* CONFIG_PNP */
+
+#ifdef CONFIG_PNP
+static unsigned int nopnp = 0;
+#else
+static const unsigned int nopnp = 1;
+#endif
+static unsigned int io = 0x248;
+static unsigned int irq = 6;
+static int dma = 2;
+
+/*
  * Basic functions
  */
 
 static inline void wbsd_unlock_config(struct wbsd_host* host)
 {
+        BUG_ON(host->config == 0);
+        
         outb(host->unlock_code, host->config);
         outb(host->unlock_code, host->config);
 }
 
 static inline void wbsd_lock_config(struct wbsd_host* host)
 {
+        BUG_ON(host->config == 0);
+        
         outb(LOCK_CODE, host->config);
 }
 
 static inline void wbsd_write_config(struct wbsd_host* host, u8 reg, u8 value)
 {
+        BUG_ON(host->config == 0);
+        
         outb(reg, host->config);
         outb(value, host->config + 1);
 }
 
 static inline u8 wbsd_read_config(struct wbsd_host* host, u8 reg)
 {
+        BUG_ON(host->config == 0);
+        
         outb(reg, host->config);
         return inb(host->config + 1);
 }
@@ -133,6 +164,13 @@ static void wbsd_init_device(struct wbsd_host* host)
         wbsd_write_index(host, WBSD_IDX_SETUP, setup);
         
         /*
+         * Set DAT3 to input
+         */
+        setup &= ~WBSD_DAT3_H;
+        wbsd_write_index(host, WBSD_IDX_SETUP, setup);
+        host->flags &= ~WBSD_FIGNORE_DETECT;
+        
+        /*
          * Read back default clock.
          */
         host->clk = wbsd_read_index(host, WBSD_IDX_CLK);
@@ -148,6 +186,14 @@ static void wbsd_init_device(struct wbsd_host* host)
         wbsd_write_index(host, WBSD_IDX_TAAC, 0x7F);
         
         /*
+         * Test for card presence
+         */
+        if (inb(host->base + WBSD_CSR) & WBSD_CARDPRESENT)
+                host->flags |= WBSD_FCARD_PRESENT;
+        else
+                host->flags &= ~WBSD_FCARD_PRESENT;
+        
+        /*
          * Enable interesting interrupts.
          */
         ier = 0;
@@ -407,8 +453,6 @@ static inline void wbsd_get_long_reply(struct wbsd_host* host,
         }
 }
 
-static irqreturn_t wbsd_irq(int irq, void *dev_id, struct pt_regs *regs);
-
 static void wbsd_send_command(struct wbsd_host* host, struct mmc_command* cmd)
 {
         int i;
@@ -646,6 +690,13 @@ static void wbsd_fill_fifo(struct wbsd_host* host)
         }
         
         wbsd_kunmap_sg(host);
+        
+        /*
+         * The controller stops sending interrupts for
+         * 'FIFO empty' under certain conditions. So we
+         * need to be a bit more pro-active.
+         */
+        tasklet_schedule(&host->fifo_tasklet);
 }
 
 static void wbsd_prepare_data(struct wbsd_host* host, struct mmc_data* data)
@@ -850,9 +901,11 @@ static void wbsd_finish_data(struct wbsd_host* host, struct mmc_data* data)
         wbsd_request_end(host, host->mrq);
 }
 
-/*
- * MMC Callbacks
- */
+/*****************************************************************************\
+ *                                                                           *
+ * MMC layer callbacks                                                       *
+ *                                                                           *
+\*****************************************************************************/
 
 static void wbsd_request(struct mmc_host* mmc, struct mmc_request* mrq)
 {
@@ -874,7 +927,7 @@ static void wbsd_request(struct mmc_host* mmc, struct mmc_request* mrq)
          * If there is no card in the slot then
          * timeout immediatly.
          */
-        if (!(inb(host->base + WBSD_CSR) & WBSD_CARDPRESENT))
+        if (!(host->flags & WBSD_FCARD_PRESENT))
         {
                 cmd->error = MMC_ERR_TIMEOUT;
                 goto done;
@@ -953,33 +1006,50 @@ static void wbsd_set_ios(struct mmc_host* mmc, struct mmc_ios* ios)
                 host->clk = clk;
         }
 
+        /*
+         * Power up card.
+         */
         if (ios->power_mode != MMC_POWER_OFF)
         {
-                /*
-                 * Power up card.
-                 */
                 pwr = inb(host->base + WBSD_CSR);
                 pwr &= ~WBSD_POWER_N;
                 outb(pwr, host->base + WBSD_CSR);
-
-                /*
-                 * This behaviour is stolen from the
-                 * Windows driver. Don't know why, but
-                 * it is needed.
-                 */
-                setup = wbsd_read_index(host, WBSD_IDX_SETUP);
-                if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
-                        setup |= WBSD_DAT3_H;
-                else
-                        setup &= ~WBSD_DAT3_H;
-                wbsd_write_index(host, WBSD_IDX_SETUP, setup);
-
-                mdelay(1);
         }
 
+        /*
+         * MMC cards need to have pin 1 high during init.
+         * Init time corresponds rather nicely with the bus mode.
+         * It wreaks havoc with the card detection though so
+         * that needs to be disabed.
+         */
+        setup = wbsd_read_index(host, WBSD_IDX_SETUP);
+        if ((ios->power_mode == MMC_POWER_ON) &&
+                (ios->bus_mode == MMC_BUSMODE_OPENDRAIN))
+        {
+                setup |= WBSD_DAT3_H;
+                host->flags |= WBSD_FIGNORE_DETECT;
+        }
+        else
+        {
+                setup &= ~WBSD_DAT3_H;
+                host->flags &= ~WBSD_FIGNORE_DETECT;
+        }
+        wbsd_write_index(host, WBSD_IDX_SETUP, setup);
+        
         spin_unlock_bh(&host->lock);
 }
 
+static struct mmc_host_ops wbsd_ops = {
+        .request        = wbsd_request,
+        .set_ios        = wbsd_set_ios,
+};
+
+/*****************************************************************************\
+ *                                                                           *
+ * Interrupt handling                                                        *
+ *                                                                           *
+\*****************************************************************************/
+
 /*
  * Tasklets
  */
@@ -1005,17 +1075,33 @@ static void wbsd_tasklet_card(unsigned long param)
 {
         struct wbsd_host* host = (struct wbsd_host*)param;
         u8 csr;
+        int change = 0;
         
         spin_lock(&host->lock);
         
+        if (host->flags & WBSD_FIGNORE_DETECT)
+        {
+                spin_unlock(&host->lock);
+                return;
+        }
+        
         csr = inb(host->base + WBSD_CSR);
         WARN_ON(csr == 0xff);
         
         if (csr & WBSD_CARDPRESENT)
-                DBG("Card inserted\n");
-        else
+        {
+                if (!(host->flags & WBSD_FCARD_PRESENT))
+                {
+                        DBG("Card inserted\n");
+                        host->flags |= WBSD_FCARD_PRESENT;
+                        change = 1;
+                }
+        }
+        else if (host->flags & WBSD_FCARD_PRESENT)
         {
                 DBG("Card removed\n");
+                host->flags &= ~WBSD_FCARD_PRESENT;
+                change = 1;
                 
                 if (host->mrq)
                 {
@@ -1033,7 +1119,8 @@ static void wbsd_tasklet_card(unsigned long param)
          */
         spin_unlock(&host->lock);
 
-        mmc_detect_change(host->mmc);
+        if (change)
+                mmc_detect_change(host->mmc);
 }
 
 static void wbsd_tasklet_fifo(unsigned long param)
@@ -1200,11 +1287,85 @@ static irqreturn_t wbsd_irq(int irq, void *dev_id, struct pt_regs *regs)
         return IRQ_HANDLED;
 }
 
+/*****************************************************************************\
+ *                                                                           *
+ * Device initialisation and shutdown                                        *
+ *                                                                           *
+\*****************************************************************************/
+
 /*
- * Support functions for probe
+ * Allocate/free MMC structure.
  */
 
-static int wbsd_scan(struct wbsd_host* host)
+static int __devinit wbsd_alloc_mmc(struct device* dev)
+{
+        struct mmc_host* mmc;
+        struct wbsd_host* host;
+        
+        /*
+         * Allocate MMC structure.
+         */
+        mmc = mmc_alloc_host(sizeof(struct wbsd_host), dev);
+        if (!mmc)
+                return -ENOMEM;
+        
+        host = mmc_priv(mmc);
+        host->mmc = mmc;
+
+        host->dma = -1;
+
+        /*
+         * Set host parameters.
+         */
+        mmc->ops = &wbsd_ops;
+        mmc->f_min = 375000;
+        mmc->f_max = 24000000;
+        mmc->ocr_avail = MMC_VDD_32_33|MMC_VDD_33_34;
+        
+        spin_lock_init(&host->lock);
+        
+        /*
+         * Maximum number of segments. Worst case is one sector per segment
+         * so this will be 64kB/512.
+         */
+        mmc->max_hw_segs = 128;
+        mmc->max_phys_segs = 128;
+        
+        /*
+         * Maximum number of sectors in one transfer. Also limited by 64kB
+         * buffer.
+         */
+        mmc->max_sectors = 128;
+        
+        /*
+         * Maximum segment size. Could be one segment with the maximum number
+         * of segments.
+         */
+        mmc->max_seg_size = mmc->max_sectors * 512;
+        
+        dev_set_drvdata(dev, mmc);
+        
+        return 0;
+}
+
+static void __devexit wbsd_free_mmc(struct device* dev)
+{
+        struct mmc_host* mmc;
+        
+        mmc = dev_get_drvdata(dev);
+        if (!mmc)
+                return;
+        
+        mmc_free_host(mmc);
+        
+        dev_set_drvdata(dev, NULL);
+}
+
+/*
+ * Scan for known chip id:s
+ */
+
+static int __devinit wbsd_scan(struct wbsd_host* host)
 {
         int i, j, k;
         int id;
@@ -1258,12 +1419,16 @@ static int wbsd_scan(struct wbsd_host* host)
         return -ENODEV;
 }
 
-static int wbsd_request_regions(struct wbsd_host* host)
+/*
+ * Allocate/free io port ranges
+ */
+
+static int __devinit wbsd_request_region(struct wbsd_host* host, int base)
 {
         if (io & 0x7)
                 return -EINVAL;
         
-        if (!request_region(io, 8, DRIVER_NAME))
+        if (!request_region(base, 8, DRIVER_NAME))
                 return -EIO;
         
         host->base = io;
@@ -1271,19 +1436,25 @@ static int wbsd_request_regions(struct wbsd_host* host)
         return 0;
 }
 
-static void wbsd_release_regions(struct wbsd_host* host)
+static void __devexit wbsd_release_regions(struct wbsd_host* host)
 {
         if (host->base)
                 release_region(host->base, 8);
+        
+        host->base = 0;
 
         if (host->config)
                 release_region(host->config, 2);
+        
+        host->config = 0;
 }
 
-static void wbsd_init_dma(struct wbsd_host* host)
+/*
+ * Allocate/free DMA port and buffer
+ */
+
+static void __devinit wbsd_request_dma(struct wbsd_host* host, int dma)
 {
-        host->dma = -1;
-        
         if (dma < 0)
                 return;
         
@@ -1294,7 +1465,7 @@ static void wbsd_init_dma(struct wbsd_host* host)
          * We need to allocate a special buffer in
          * order for ISA to be able to DMA to it.
          */
-        host->dma_buffer = kmalloc(65536,
+        host->dma_buffer = kmalloc(WBSD_DMA_SIZE,
                 GFP_NOIO | GFP_DMA | __GFP_REPEAT | __GFP_NOWARN);
         if (!host->dma_buffer)
                 goto free;
@@ -1302,7 +1473,8 @@ static void wbsd_init_dma(struct wbsd_host* host)
         /*
          * Translate the address to a physical address.
          */
-        host->dma_addr = isa_virt_to_bus(host->dma_buffer);
+        host->dma_addr = dma_map_single(host->mmc->dev, host->dma_buffer,
+                WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
                         
         /*
          * ISA DMA must be aligned on a 64k basis.
@@ -1325,6 +1497,10 @@ kfree:
          */
         BUG_ON(1);
         
+        dma_unmap_single(host->mmc->dev, host->dma_addr, WBSD_DMA_SIZE,
+                DMA_BIDIRECTIONAL);
+        host->dma_addr = (dma_addr_t)NULL;
+        
         kfree(host->dma_buffer);
         host->dma_buffer = NULL;
 
@@ -1336,60 +1512,122 @@ err:
                 "Falling back on FIFO.\n", dma);
 }
 
-static struct mmc_host_ops wbsd_ops = {
-        .request        = wbsd_request,
-        .set_ios        = wbsd_set_ios,
-};
+static void __devexit wbsd_release_dma(struct wbsd_host* host)
+{
+        if (host->dma_addr)
+                dma_unmap_single(host->mmc->dev, host->dma_addr, WBSD_DMA_SIZE,
+                        DMA_BIDIRECTIONAL);
+        if (host->dma_buffer)
+                kfree(host->dma_buffer);
+        if (host->dma >= 0)
+                free_dma(host->dma);
+        
+        host->dma = -1;
+        host->dma_buffer = NULL;
+        host->dma_addr = (dma_addr_t)NULL;
+}
 
 /*
- * Device probe
+ * Allocate/free IRQ.
  */
 
-static int wbsd_probe(struct device* dev)
+static int __devinit wbsd_request_irq(struct wbsd_host* host, int irq)
 {
-        struct wbsd_host* host = NULL;
-        struct mmc_host* mmc = NULL;
         int ret;
         
         /*
-         * Allocate MMC structure.
+         * Allocate interrupt.
          */
-        mmc = mmc_alloc_host(sizeof(struct wbsd_host), dev);
-        if (!mmc)
-                return -ENOMEM;
-        
-        host = mmc_priv(mmc);
-        host->mmc = mmc;
+
+        ret = request_irq(irq, wbsd_irq, SA_SHIRQ, DRIVER_NAME, host);
+        if (ret)
+                return ret;
         
+        host->irq = irq;
+
         /*
-         * Scan for hardware.
+         * Set up tasklets.
          */
-        ret = wbsd_scan(host);
-        if (ret)
-                goto freemmc;
+        tasklet_init(&host->card_tasklet, wbsd_tasklet_card, (unsigned long)host);
+        tasklet_init(&host->fifo_tasklet, wbsd_tasklet_fifo, (unsigned long)host);
+        tasklet_init(&host->crc_tasklet, wbsd_tasklet_crc, (unsigned long)host);
+        tasklet_init(&host->timeout_tasklet, wbsd_tasklet_timeout, (unsigned long)host);
+        tasklet_init(&host->finish_tasklet, wbsd_tasklet_finish, (unsigned long)host);
+        tasklet_init(&host->block_tasklet, wbsd_tasklet_block, (unsigned long)host);
+        
+        return 0;
+}
 
-        /*
-         * Reset the chip.
-         */     
-        wbsd_write_config(host, WBSD_CONF_SWRST, 1);
-        wbsd_write_config(host, WBSD_CONF_SWRST, 0);
+static void __devexit wbsd_release_irq(struct wbsd_host* host)
+{
+        if (!host->irq)
+                return;
 
+        free_irq(host->irq, host);
+        
+        host->irq = 0;
+                
+        tasklet_kill(&host->card_tasklet);
+        tasklet_kill(&host->fifo_tasklet);
+        tasklet_kill(&host->crc_tasklet);
+        tasklet_kill(&host->timeout_tasklet);
+        tasklet_kill(&host->finish_tasklet);
+        tasklet_kill(&host->block_tasklet);
+}
+
+/*
+ * Allocate all resources for the host.
+ */
+
+static int __devinit wbsd_request_resources(struct wbsd_host* host,
+        int base, int irq, int dma)
+{
+        int ret;
+        
         /*
          * Allocate I/O ports.
          */
-        ret = wbsd_request_regions(host);
+        ret = wbsd_request_region(host, base);
         if (ret)
-                goto release;
+                return ret;
 
         /*
-         * Set host parameters.
+         * Allocate interrupt.
          */
-        mmc->ops = &wbsd_ops;
-        mmc->f_min = 375000;
-        mmc->f_max = 24000000;
-        mmc->ocr_avail = MMC_VDD_32_33|MMC_VDD_33_34;
+        ret = wbsd_request_irq(host, irq);
+        if (ret)
+                return ret;
+
+        /*
+         * Allocate DMA.
+         */
+        wbsd_request_dma(host, dma);
         
-        spin_lock_init(&host->lock);
+        return 0;
+}
+
+/*
+ * Release all resources for the host.
+ */
+
+static void __devexit wbsd_release_resources(struct wbsd_host* host)
+{
+        wbsd_release_dma(host);
+        wbsd_release_irq(host);
+        wbsd_release_regions(host);
+}
+
+/*
+ * Configure the resources the chip should use.
+ */
+
+static void __devinit wbsd_chip_config(struct wbsd_host* host)
+{
+        /*
+         * Reset the chip.
+         */     
+        wbsd_write_config(host, WBSD_CONF_SWRST, 1);
+        wbsd_write_config(host, WBSD_CONF_SWRST, 0);
 
         /*
          * Select SD/MMC function.
@@ -1399,165 +1637,241 @@ static int wbsd_probe(struct device* dev)
         /*
          * Set up card detection.
          */
-        wbsd_write_config(host, WBSD_CONF_PINS, 0x02);
+        wbsd_write_config(host, WBSD_CONF_PINS, WBSD_PINS_DETECT_GP11);
         
         /*
-         * Configure I/O port.
+         * Configure chip
          */
         wbsd_write_config(host, WBSD_CONF_PORT_HI, host->base >> 8);
         wbsd_write_config(host, WBSD_CONF_PORT_LO, host->base & 0xff);
-
-        /*
-         * Allocate interrupt.
-         */
-        ret = request_irq(irq, wbsd_irq, SA_SHIRQ, DRIVER_NAME, host);
-        if (ret)
-                goto release;
         
-        host->irq = irq;
+        wbsd_write_config(host, WBSD_CONF_IRQ, host->irq);
         
-        /*
-         * Set up tasklets.
-         */
-        tasklet_init(&host->card_tasklet, wbsd_tasklet_card, (unsigned long)host);
-        tasklet_init(&host->fifo_tasklet, wbsd_tasklet_fifo, (unsigned long)host);
-        tasklet_init(&host->crc_tasklet, wbsd_tasklet_crc, (unsigned long)host);
-        tasklet_init(&host->timeout_tasklet, wbsd_tasklet_timeout, (unsigned long)host);
-        tasklet_init(&host->finish_tasklet, wbsd_tasklet_finish, (unsigned long)host);
-        tasklet_init(&host->block_tasklet, wbsd_tasklet_block, (unsigned long)host);
+        if (host->dma >= 0)
+                wbsd_write_config(host, WBSD_CONF_DRQ, host->dma);
         
         /*
-         * Configure interrupt.
+         * Enable and power up chip.
          */
-        wbsd_write_config(host, WBSD_CONF_IRQ, host->irq);
+        wbsd_write_config(host, WBSD_CONF_ENABLE, 1);
+        wbsd_write_config(host, WBSD_CONF_POWER, 0x20);
+}
+
+/*
+ * Check that configured resources are correct.
+ */
+ 
+static int __devinit wbsd_chip_validate(struct wbsd_host* host)
+{
+        int base, irq, dma;
         
         /*
-         * Allocate DMA.
+         * Select SD/MMC function.
          */
-        wbsd_init_dma(host);
+        wbsd_write_config(host, WBSD_CONF_DEVICE, DEVICE_SD);
         
         /*
-         * If all went well, then configure DMA.
+         * Read configuration.
          */
-        if (host->dma >= 0)
-                wbsd_write_config(host, WBSD_CONF_DRQ, host->dma);
+        base = wbsd_read_config(host, WBSD_CONF_PORT_HI) << 8;
+        base |= wbsd_read_config(host, WBSD_CONF_PORT_LO);
         
-        /*
-         * Maximum number of segments. Worst case is one sector per segment
-         * so this will be 64kB/512.
-         */
-        mmc->max_hw_segs = 128;
-        mmc->max_phys_segs = 128;
+        irq = wbsd_read_config(host, WBSD_CONF_IRQ);
+        
+        dma = wbsd_read_config(host, WBSD_CONF_DRQ);
         
         /*
-         * Maximum number of sectors in one transfer. Also limited by 64kB
-         * buffer.
+         * Validate against given configuration.
          */
-        mmc->max_sectors = 128;
+        if (base != host->base)
+                return 0;
+        if (irq != host->irq)
+                return 0;
+        if ((dma != host->dma) && (host->dma != -1))
+                return 0;
+        
+        return 1;
+}
+
+/*****************************************************************************\
+ *                                                                           *
+ * Devices setup and shutdown                                                *
+ *                                                                           *
+\*****************************************************************************/
+
+static int __devinit wbsd_init(struct device* dev, int base, int irq, int dma,
+        int pnp)
+{
+        struct wbsd_host* host = NULL;
+        struct mmc_host* mmc = NULL;
+        int ret;
+        
+        ret = wbsd_alloc_mmc(dev);
+        if (ret)
+                return ret;
+        
+        mmc = dev_get_drvdata(dev);
+        host = mmc_priv(mmc);
         
         /*
-         * Maximum segment size. Could be one segment with the maximum number
-         * of segments.
+         * Scan for hardware.
          */
-        mmc->max_seg_size = mmc->max_sectors * 512;
+        ret = wbsd_scan(host);
+        if (ret)
+        {
+                if (pnp && (ret == -ENODEV))
+                {
+                        printk(KERN_WARNING DRIVER_NAME
+                                ": Unable to confirm device presence. You may "
+                                "experience lock-ups.\n");
+                }
+                else
+                {
+                        wbsd_free_mmc(dev);
+                        return ret;
+                }
+        }
         
         /*
-         * Enable chip.
+         * Request resources.
          */
-        wbsd_write_config(host, WBSD_CONF_ENABLE, 1);
+        ret = wbsd_request_resources(host, io, irq, dma);
+        if (ret)
+        {
+                wbsd_release_resources(host);
+                wbsd_free_mmc(dev);
+                return ret;
+        }
         
         /*
-         * Power up chip.
+         * See if chip needs to be configured.
          */
-        wbsd_write_config(host, WBSD_CONF_POWER, 0x20);
+        if (pnp && (host->config != 0))
+        {
+                if (!wbsd_chip_validate(host))
+                {
+                        printk(KERN_WARNING DRIVER_NAME
+                                ": PnP active but chip not configured! "
+                                "You probably have a buggy BIOS. "
+                                "Configuring chip manually.\n");
+                        wbsd_chip_config(host);
+                }
+        }
+        else
+                wbsd_chip_config(host);
         
         /*
          * Power Management stuff. No idea how this works.
          * Not tested.
          */
 #ifdef CONFIG_PM
-        wbsd_write_config(host, WBSD_CONF_PME, 0xA0);
+        if (host->config)
+                wbsd_write_config(host, WBSD_CONF_PME, 0xA0);
 #endif
+        /*
+         * Allow device to initialise itself properly.
+         */
+        mdelay(5);
 
         /*
          * Reset the chip into a known state.
          */
         wbsd_init_device(host);
         
-        dev_set_drvdata(dev, mmc);
-        
-        /*
-         * Add host to MMC layer.
-         */
         mmc_add_host(mmc);
 
-        printk(KERN_INFO "%s: W83L51xD id %x at 0x%x irq %d dma %d\n",
-                mmc->host_name, (int)host->chip_id, (int)host->base,
-                (int)host->irq, (int)host->dma);
+        printk(KERN_INFO "%s: W83L51xD", mmc->host_name);
+        if (host->chip_id != 0)
+                printk(" id %x", (int)host->chip_id);
+        printk(" at 0x%x irq %d", (int)host->base, (int)host->irq);
+        if (host->dma >= 0)
+                printk(" dma %d", (int)host->dma);
+        else
+                printk(" FIFO");
+        if (pnp)
+                printk(" PnP");
+        printk("\n");
 
         return 0;
-
-release:
-        wbsd_release_regions(host);
-
-freemmc:
-        mmc_free_host(mmc);
-
-        return ret;
 }
 
-/*
- * Device remove
- */
-
-static int wbsd_remove(struct device* dev)
+static void __devexit wbsd_shutdown(struct device* dev, int pnp)
 {
         struct mmc_host* mmc = dev_get_drvdata(dev);
         struct wbsd_host* host;
         
         if (!mmc)
-                return 0;
+                return;
 
         host = mmc_priv(mmc);
         
-        /*
-         * Unregister host with MMC layer.
-         */
         mmc_remove_host(mmc);
 
-        /*
-         * Power down the SD/MMC function.
-         */
-        wbsd_unlock_config(host);
-        wbsd_write_config(host, WBSD_CONF_DEVICE, DEVICE_SD);
-        wbsd_write_config(host, WBSD_CONF_ENABLE, 0);
-        wbsd_lock_config(host);
+        if (!pnp)
+        {
+                /*
+                 * Power down the SD/MMC function.
+                 */
+                wbsd_unlock_config(host);
+                wbsd_write_config(host, WBSD_CONF_DEVICE, DEVICE_SD);
+                wbsd_write_config(host, WBSD_CONF_ENABLE, 0);
+                wbsd_lock_config(host);
+        }
         
-        /*
-         * Free resources.
-         */
-        if (host->dma_buffer)
-                kfree(host->dma_buffer);
+        wbsd_release_resources(host);
         
-        if (host->dma >= 0)
-                free_dma(host->dma);
+        wbsd_free_mmc(dev);
+}
 
-        free_irq(host->irq, host);
+/*
+ * Non-PnP
+ */
+
+static int __devinit wbsd_probe(struct device* dev)
+{
+        return wbsd_init(dev, io, irq, dma, 0);
+}
+
+static int __devexit wbsd_remove(struct device* dev)
+{
+        wbsd_shutdown(dev, 0);
+
+        return 0;
+}
+
+/*
+ * PnP
+ */
+
+#ifdef CONFIG_PNP
+
+static int __devinit
+wbsd_pnp_probe(struct pnp_dev * pnpdev, const struct pnp_device_id *dev_id)
+{
+        int io, irq, dma;
         
-        tasklet_kill(&host->card_tasklet);
-        tasklet_kill(&host->fifo_tasklet);
-        tasklet_kill(&host->crc_tasklet);
-        tasklet_kill(&host->timeout_tasklet);
-        tasklet_kill(&host->finish_tasklet);
-        tasklet_kill(&host->block_tasklet);
+        /*
+         * Get resources from PnP layer.
+         */
+        io = pnp_port_start(pnpdev, 0);
+        irq = pnp_irq(pnpdev, 0);
+        if (pnp_dma_valid(pnpdev, 0))
+                dma = pnp_dma(pnpdev, 0);
+        else
+                dma = -1;
         
-        wbsd_release_regions(host);
+        DBGF("PnP resources: port %3x irq %d dma %d\n", io, irq, dma);
         
-        mmc_free_host(mmc);
+        return wbsd_init(&pnpdev->dev, io, irq, dma, 1);
+}
 
-        return 0;
+static void __devexit wbsd_pnp_remove(struct pnp_dev * dev)
+{
+        wbsd_shutdown(&dev->dev, 1);
 }
 
+#endif /* CONFIG_PNP */
+
 /*
  * Power management
  */
@@ -1581,17 +1895,7 @@ static int wbsd_resume(struct device *dev, u32 level)
 #define wbsd_resume NULL
 #endif
 
-static void wbsd_release(struct device *dev)
-{
-}
-
-static struct platform_device wbsd_device = {
-        .name           = DRIVER_NAME,
-        .id                     = -1,
-        .dev            = {
-                .release = wbsd_release,
-        },
-};
+static struct platform_device *wbsd_device;
 
 static struct device_driver wbsd_driver = {
         .name           = DRIVER_NAME,
@@ -1603,6 +1907,17 @@ static struct device_driver wbsd_driver = {
         .resume         = wbsd_resume,
 };
 
+#ifdef CONFIG_PNP
+
+static struct pnp_driver wbsd_pnp_driver = {
+        .name           = DRIVER_NAME,
+        .id_table       = pnp_dev_table,
+        .probe          = wbsd_pnp_probe,
+        .remove         = wbsd_pnp_remove,
+};
+
+#endif /* CONFIG_PNP */
+
 /*
  * Module loading/unloading
  */
@@ -1615,29 +1930,57 @@ static int __init wbsd_drv_init(void)
                 ": Winbond W83L51xD SD/MMC card interface driver, "
                 DRIVER_VERSION "\n");
         printk(KERN_INFO DRIVER_NAME ": Copyright(c) Pierre Ossman\n");
-        
-        result = driver_register(&wbsd_driver);
-        if (result < 0)
-                return result;
 
-        result = platform_device_register(&wbsd_device);
-        if (result < 0)
-                return result;
+#ifdef CONFIG_PNP
+
+        if (!nopnp)
+        {
+                result = pnp_register_driver(&wbsd_pnp_driver);
+                if (result < 0)
+                        return result;
+        }
+
+#endif /* CONFIG_PNP */ 
+        
+        if (nopnp)
+        {
+                result = driver_register(&wbsd_driver);
+                if (result < 0)
+                        return result;
+
+                wbsd_device = platform_device_register_simple(DRIVER_NAME, -1,
+                        NULL, 0);
+                if (IS_ERR(wbsd_device))
+                        return PTR_ERR(wbsd_device);
+        }
 
         return 0;
 }
 
 static void __exit wbsd_drv_exit(void)
 {
-        platform_device_unregister(&wbsd_device);
+#ifdef CONFIG_PNP
+
+        if (!nopnp)
+                pnp_unregister_driver(&wbsd_pnp_driver);
         
-        driver_unregister(&wbsd_driver);
+#endif /* CONFIG_PNP */ 
+
+        if (nopnp)
+        {
+                platform_device_unregister(wbsd_device);
+        
+                driver_unregister(&wbsd_driver);
+        }
 
         DBG("unloaded\n");
 }
 
 module_init(wbsd_drv_init);
 module_exit(wbsd_drv_exit);
+#ifdef CONFIG_PNP
+module_param(nopnp, uint, 0444);
+#endif
 module_param(io, uint, 0444);
 module_param(irq, uint, 0444);
 module_param(dma, int, 0444);
@@ -1646,6 +1989,9 @@ MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Winbond W83L51xD SD/MMC card interface driver");
 MODULE_VERSION(DRIVER_VERSION);
 
+#ifdef CONFIG_PNP
+MODULE_PARM_DESC(nopnp, "Scan for device instead of relying on PNP. (default 0)");
+#endif
 MODULE_PARM_DESC(io, "I/O base to allocate. Must be 8 byte aligned. (default 0x248)");
 MODULE_PARM_DESC(irq, "IRQ to allocate. (default 6)");
 MODULE_PARM_DESC(dma, "DMA channel to allocate. -1 for no DMA. (default 2)");