mtd: docg3: add multiple floor support

Add support for multiple floors, ie. cascaded docg3
chips. There might be 4 docg3 chips cascaded, sharing the
same address space, and providing up to 4 times the storage
capacity of a unique chip.

Each floor will be seen as an independant mtd device.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index 1c2f54d..6eca7f6 100644 (file)
--- a/drivers/mtd/devices/docg3.c
+++ b/drivers/mtd/devices/docg3.c
@@ -948,7 +948,8 @@ static void __init doc_set_driver_info(int chip_id, struct mtd_info *mtd)
 
        switch (chip_id) {
        case DOC_CHIPID_G3:
-               mtd->name = "DiskOnChip G3";
+               mtd->name = kasprintf(GFP_KERNEL, "DiskOnChip G3 floor %d",
+                                     docg3->device_id);
                docg3->max_block = 2047;
                break;
        }
@@ -975,22 +976,24 @@ static void __init doc_set_driver_info(int chip_id, struct mtd_info *mtd)
 }
 
 /**
- * doc_probe - Probe the IO space for a DiskOnChip G3 chip
- * @pdev: platform device
+ * doc_probe_device - Check if a device is available
+ * @base: the io space where the device is probed
+ * @floor: the floor of the probed device
+ * @dev: the device
  *
- * Probes for a G3 chip at the specified IO space in the platform data
- * ressources.
+ * Checks whether a device at the specified IO range, and floor is available.
  *
- * Returns 0 on success, -ENOMEM, -ENXIO on error
+ * Returns a mtd_info struct if there is a device, ENODEV if none found, ENOMEM
+ * if a memory allocation failed. If floor 0 is checked, a reset of the ASIC is
+ * launched.
  */
-static int __init docg3_probe(struct platform_device *pdev)
+static struct mtd_info *doc_probe_device(void __iomem *base, int floor,
+                                        struct device *dev)
 {
-       struct device *dev = &pdev->dev;
-       struct docg3 *docg3;
-       struct mtd_info *mtd;
-       struct resource *ress;
        int ret, bbt_nbpages;
        u16 chip_id, chip_id_inv;
+       struct docg3 *docg3;
+       struct mtd_info *mtd;
 
        ret = -ENOMEM;
        docg3 = kzalloc(sizeof(struct docg3), GFP_KERNEL);
@@ -1000,69 +1003,132 @@ static int __init docg3_probe(struct platform_device *pdev)
        if (!mtd)
                goto nomem2;
        mtd->priv = docg3;
+       bbt_nbpages = DIV_ROUND_UP(docg3->max_block + 1,
+                                  8 * DOC_LAYOUT_PAGE_SIZE);
+       docg3->bbt = kzalloc(bbt_nbpages * DOC_LAYOUT_PAGE_SIZE, GFP_KERNEL);
+       if (!docg3->bbt)
+               goto nomem3;
 
-       ret = -ENXIO;
-       ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-       if (!ress) {
-               dev_err(dev, "No I/O memory resource defined\n");
-               goto noress;
-       }
-       docg3->base = ioremap(ress->start, DOC_IOSPACE_SIZE);
-
-       docg3->dev = &pdev->dev;
-       docg3->device_id = 0;
+       docg3->dev = dev;
+       docg3->device_id = floor;
+       docg3->base = base;
        doc_set_device_id(docg3, docg3->device_id);
-       doc_set_asic_mode(docg3, DOC_ASICMODE_RESET);
+       if (!floor)
+               doc_set_asic_mode(docg3, DOC_ASICMODE_RESET);
        doc_set_asic_mode(docg3, DOC_ASICMODE_NORMAL);
 
        chip_id = doc_register_readw(docg3, DOC_CHIPID);
        chip_id_inv = doc_register_readw(docg3, DOC_CHIPID_INV);
 
-       ret = -ENODEV;
+       ret = 0;
        if (chip_id != (u16)(~chip_id_inv)) {
-               doc_info("No device found at IO addr %p\n",
-                        (void *)ress->start);
-               goto nochipfound;
+               goto nomem3;
        }
 
        switch (chip_id) {
        case DOC_CHIPID_G3:
-               doc_info("Found a G3 DiskOnChip at addr %p\n",
-                        (void *)ress->start);
+               doc_info("Found a G3 DiskOnChip at addr %p, floor %d\n",
+                        base, floor);
                break;
        default:
                doc_err("Chip id %04x is not a DiskOnChip G3 chip\n", chip_id);
-               goto nochipfound;
+               goto nomem3;
        }
 
        doc_set_driver_info(chip_id, mtd);
-       platform_set_drvdata(pdev, mtd);
 
-       ret = -ENOMEM;
-       bbt_nbpages = DIV_ROUND_UP(docg3->max_block + 1,
-                                  8 * DOC_LAYOUT_PAGE_SIZE);
-       docg3->bbt = kzalloc(bbt_nbpages * DOC_LAYOUT_PAGE_SIZE, GFP_KERNEL);
-       if (!docg3->bbt)
-               goto nochipfound;
        doc_reload_bbt(docg3);
+       return mtd;
 
-       ret = mtd_device_parse_register(mtd, part_probes,
-                                       NULL, NULL, 0);
-       if (ret)
-               goto register_error;
-
-       doc_dbg_register(docg3);
-       return 0;
-
-register_error:
-       kfree(docg3->bbt);
-nochipfound:
-       iounmap(docg3->base);
-noress:
+nomem3:
        kfree(mtd);
 nomem2:
        kfree(docg3);
 nomem1:
+       return ERR_PTR(ret);
+}
+
+/**
+ * doc_release_device - Release a docg3 floor
+ * @mtd: the device
+ */
+static void doc_release_device(struct mtd_info *mtd)
+{
+       struct docg3 *docg3 = mtd->priv;
+
+       mtd_device_unregister(mtd);
+       kfree(docg3->bbt);
+       kfree(docg3);
+       kfree(mtd->name);
+       kfree(mtd);
+}
+
+/**
+ * doc_probe - Probe the IO space for a DiskOnChip G3 chip
+ * @pdev: platform device
+ *
+ * Probes for a G3 chip at the specified IO space in the platform data
+ * ressources. The floor 0 must be available.
+ *
+ * Returns 0 on success, -ENOMEM, -ENXIO on error
+ */
+static int __init docg3_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct mtd_info *mtd;
+       struct resource *ress;
+       void __iomem *base;
+       int ret, floor, found = 0;
+       struct mtd_info **docg3_floors;
+
+       ret = -ENXIO;
+       ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!ress) {
+               dev_err(dev, "No I/O memory resource defined\n");
+               goto noress;
+       }
+       base = ioremap(ress->start, DOC_IOSPACE_SIZE);
+
+       ret = -ENOMEM;
+       docg3_floors = kzalloc(sizeof(*docg3_floors) * DOC_MAX_NBFLOORS,
+                              GFP_KERNEL);
+       if (!docg3_floors)
+               goto nomem;
+
+       ret = 0;
+       for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
+               mtd = doc_probe_device(base, floor, dev);
+               if (floor == 0 && !mtd)
+                       goto notfound;
+               if (!IS_ERR_OR_NULL(mtd))
+                       ret = mtd_device_parse_register(mtd, part_probes,
+                                                       NULL, NULL, 0);
+               else
+                       ret = PTR_ERR(mtd);
+               docg3_floors[floor] = mtd;
+               if (ret)
+                       goto err_probe;
+               if (mtd)
+                       found++;
+       }
+
+       if (!found)
+               goto notfound;
+
+       platform_set_drvdata(pdev, docg3_floors);
+       doc_dbg_register(docg3_floors[0]->priv);
+       return 0;
+
+notfound:
+       ret = -ENODEV;
+       dev_info(dev, "No supported DiskOnChip found\n");
+err_probe:
+       for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
+               if (docg3_floors[floor])
+                       doc_release_device(docg3_floors[floor]);
+nomem:
+       iounmap(base);
+noress:
        return ret;
 }
 
@@ -1074,15 +1140,18 @@ nomem1:
  */
 static int __exit docg3_release(struct platform_device *pdev)
 {
-       struct mtd_info *mtd = platform_get_drvdata(pdev);
-       struct docg3 *docg3 = mtd->priv;
+       struct mtd_info **docg3_floors = platform_get_drvdata(pdev);
+       struct docg3 *docg3 = docg3_floors[0]->priv;
+       void __iomem *base = docg3->base;
+       int floor;
 
        doc_dbg_unregister(docg3);
-       mtd_device_unregister(mtd);
-       iounmap(docg3->base);
-       kfree(docg3->bbt);
-       kfree(docg3);
-       kfree(mtd);
+       for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
+               if (docg3_floors[floor])
+                       doc_release_device(docg3_floors[floor]);
+
+       kfree(docg3_floors);
+       iounmap(base);
        return 0;
 }
 

diff --git a/drivers/mtd/devices/docg3.h b/drivers/mtd/devices/docg3.h
index 62af5aa..75df3a1 100644 (file)
--- a/drivers/mtd/devices/docg3.h
+++ b/drivers/mtd/devices/docg3.h
@@ -80,6 +80,7 @@
 
 #define DOC_CHIPID_G3                  0x200
 #define DOC_ERASE_MARK                 0xaa
+#define DOC_MAX_NBFLOORS               4
 /*
  * Flash registers
  */