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Subject[PATCH v3 06/16] mtd/docg3: add multiple floor support
Date
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>
---
drivers/mtd/devices/docg3.c | 181 +++++++++++++++++++++++++++++-------------
drivers/mtd/devices/docg3.h | 1 +
2 files changed, 126 insertions(+), 56 deletions(-)
diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index 1c2f54d..6eca7f6 100644
--- 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
--- 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
*/
--
1.7.5.4


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