[PATCH v3 1/4] mtd: nand: gpio: Add DT property to automatically determine bus width
Alexander Shiyan
shc_work at mail.ru
Tue Aug 6 04:57:38 EDT 2013
This patch adds a property to automatically determine the NAND
bus width. This property works if the bus width is not specified
explicitly.
Signed-off-by: Alexander Shiyan <shc_work at mail.ru>
---
.../devicetree/bindings/mtd/gpio-control-nand.txt | 2 ++
drivers/mtd/nand/gpio.c | 16 ++++++++++++----
2 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt b/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt
index 36ef07d..91070d0 100644
--- a/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt
@@ -19,6 +19,8 @@ Optional properties:
defaults to 1 byte.
- chip-delay : chip dependent delay for transferring data from array to
read registers (tR). If not present then a default of 20us is used.
+- gpio-control-nand,bank-width-auto : Device bus width is determined
+ automatically if "bank-width" is omitted (Boolean).
- gpio-control-nand,io-sync-reg : A 64-bit physical address for a read
location used to guard against bus reordering with regards to accesses to
the GPIO's and the NAND flash data bus. If present, then after changing
diff --git a/drivers/mtd/nand/gpio.c b/drivers/mtd/nand/gpio.c
index 800a1cc..c75f92e 100644
--- a/drivers/mtd/nand/gpio.c
+++ b/drivers/mtd/nand/gpio.c
@@ -116,6 +116,10 @@ static int gpio_nand_get_config_of(const struct device *dev,
dev_err(dev, "invalid bank-width %u\n", val);
return -EINVAL;
}
+ } else {
+ if (of_get_property(dev->of_node,
+ "gpio-control-nand,bank-width-auto", NULL))
+ plat->options |= NAND_BUSWIDTH_AUTO;
}
plat->gpio_rdy = of_get_gpio(dev->of_node, 0);
@@ -223,6 +227,14 @@ static int gpio_nand_probe(struct platform_device *pdev)
if (IS_ERR(chip->IO_ADDR_R))
return PTR_ERR(chip->IO_ADDR_R);
+ ret = gpio_nand_get_config(&pdev->dev, &gpiomtd->plat);
+ if (ret)
+ return ret;
+
+ if (resource_size(res) < 2)
+ gpiomtd->plat.options &= ~(NAND_BUSWIDTH_16 |
+ NAND_BUSWIDTH_AUTO);
+
res = gpio_nand_get_io_sync(pdev);
if (res) {
gpiomtd->io_sync = devm_ioremap_resource(&pdev->dev, res);
@@ -230,10 +242,6 @@ static int gpio_nand_probe(struct platform_device *pdev)
return PTR_ERR(gpiomtd->io_sync);
}
- ret = gpio_nand_get_config(&pdev->dev, &gpiomtd->plat);
- if (ret)
- return ret;
-
ret = devm_gpio_request(&pdev->dev, gpiomtd->plat.gpio_nce, "NAND NCE");
if (ret)
return ret;
--
1.8.1.5
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