[4/6] mtd: rawnand: gpio: Use device properties
Commit Message
The platform data (struct gpio_nand_platdata) isn't really used
in any boardfile in the kernel: the only probe path is from
device tree.
Convert the driver to not use the platform data header at all
and read out the device tree properties using device
properties so we don't need to have the driver be exclusively
device tree either: ACPI or software nodes work fine if
need be. Drop the ifdeffery around CONFIG_OF as a consequence.
The code reads "bank-width" to plat->options flags and passes
it directly to the NAND chip struct, so just assign this
directly to the chip instead.
The code reads one property "chip-delay" that it stores
in pdata->delay and never use, so drop this altogether.
If timings should be supported this can probably be done in
a more detailed way using the new elaborate timings structs
that exist for NAND.
The platform data contains a callback to augment partitions,
but since there are no board files using this platform
data to define a gpio NAND device, this is never used so
the code handling it can be deleted.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/mtd/nand/raw/gpio.c | 72 ++++++++-------------------------------------
1 file changed, 12 insertions(+), 60 deletions(-)
Comments
Hi Linus,
linus.walleij@linaro.org wrote on Wed, 08 Nov 2023 15:33:52 +0100:
> The platform data (struct gpio_nand_platdata) isn't really used
> in any boardfile in the kernel: the only probe path is from
> device tree.
>
> Convert the driver to not use the platform data header at all
> and read out the device tree properties using device
> properties so we don't need to have the driver be exclusively
> device tree either: ACPI or software nodes work fine if
> need be. Drop the ifdeffery around CONFIG_OF as a consequence.
>
> The code reads "bank-width" to plat->options flags and passes
> it directly to the NAND chip struct, so just assign this
> directly to the chip instead.
>
> The code reads one property "chip-delay" that it stores
> in pdata->delay and never use, so drop this altogether.
> If timings should be supported this can probably be done in
> a more detailed way using the new elaborate timings structs
> that exist for NAND.
>
> The platform data contains a callback to augment partitions,
> but since there are no board files using this platform
> data to define a gpio NAND device, this is never used so
> the code handling it can be deleted.
Nice cleanup. I'm a bit more reluctant on the bindings side, I'll come
back to it later, but the driver side looks neat.
Thanks,
Miquèl
@@ -22,9 +22,7 @@
#include <linux/mtd/mtd.h>
#include <linux/mtd/rawnand.h>
#include <linux/mtd/partitions.h>
-#include <linux/mtd/nand-gpio.h>
-#include <linux/of.h>
-#include <linux/of_address.h>
+#include <linux/property.h>
#include <linux/delay.h>
struct gpiomtd {
@@ -32,7 +30,6 @@ struct gpiomtd {
void __iomem *io;
void __iomem *io_sync;
struct nand_chip nand_chip;
- struct gpio_nand_platdata plat;
struct gpio_desc *ce; /* Optional chip enable */
struct gpio_desc *cle;
struct gpio_desc *ale;
@@ -175,46 +172,38 @@ static const struct nand_controller_ops gpio_nand_ops = {
.attach_chip = gpio_nand_attach_chip,
};
-#ifdef CONFIG_OF
static const struct of_device_id gpio_nand_id_table[] = {
{ .compatible = "gpio-control-nand" },
{}
};
MODULE_DEVICE_TABLE(of, gpio_nand_id_table);
-static int gpio_nand_get_config_of(const struct device *dev,
- struct gpio_nand_platdata *plat)
+static int gpio_nand_get_config(struct device *dev,
+ struct nand_chip *chip)
{
u32 val;
- if (!dev->of_node)
- return -ENODEV;
-
- if (!of_property_read_u32(dev->of_node, "bank-width", &val)) {
+ if (!device_property_read_u32(dev, "bank-width", &val)) {
if (val == 2) {
- plat->options |= NAND_BUSWIDTH_16;
+ chip->options |= NAND_BUSWIDTH_16;
} else if (val != 1) {
dev_err(dev, "invalid bank-width %u\n", val);
return -EINVAL;
}
}
- if (!of_property_read_u32(dev->of_node, "chip-delay", &val))
- plat->chip_delay = val;
-
return 0;
}
-static struct resource *gpio_nand_get_io_sync_of(struct platform_device *pdev)
+static struct resource *gpio_nand_get_io_sync_prop(struct device *dev)
{
struct resource *r;
u64 addr;
- if (of_property_read_u64(pdev->dev.of_node,
- "gpio-control-nand,io-sync-reg", &addr))
+ if (device_property_read_u64(dev, "gpio-control-nand,io-sync-reg", &addr))
return NULL;
- r = devm_kzalloc(&pdev->dev, sizeof(*r), GFP_KERNEL);
+ r = devm_kzalloc(dev, sizeof(*r), GFP_KERNEL);
if (!r)
return NULL;
@@ -224,40 +213,11 @@ static struct resource *gpio_nand_get_io_sync_of(struct platform_device *pdev)
return r;
}
-#else /* CONFIG_OF */
-static inline int gpio_nand_get_config_of(const struct device *dev,
- struct gpio_nand_platdata *plat)
-{
- return -ENOSYS;
-}
-
-static inline struct resource *
-gpio_nand_get_io_sync_of(struct platform_device *pdev)
-{
- return NULL;
-}
-#endif /* CONFIG_OF */
-
-static inline int gpio_nand_get_config(const struct device *dev,
- struct gpio_nand_platdata *plat)
-{
- int ret = gpio_nand_get_config_of(dev, plat);
-
- if (!ret)
- return ret;
-
- if (dev_get_platdata(dev)) {
- memcpy(plat, dev_get_platdata(dev), sizeof(*plat));
- return 0;
- }
-
- return -EINVAL;
-}
static inline struct resource *
gpio_nand_get_io_sync(struct platform_device *pdev)
{
- struct resource *r = gpio_nand_get_io_sync_of(pdev);
+ struct resource *r = gpio_nand_get_io_sync_prop(&pdev->dev);
if (r)
return r;
@@ -291,9 +251,6 @@ static int gpio_nand_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
int ret = 0;
- if (!dev->of_node && !dev_get_platdata(dev))
- return -EINVAL;
-
gpiomtd = devm_kzalloc(dev, sizeof(*gpiomtd), GFP_KERNEL);
if (!gpiomtd)
return -ENOMEM;
@@ -311,7 +268,7 @@ static int gpio_nand_probe(struct platform_device *pdev)
return PTR_ERR(gpiomtd->io_sync);
}
- ret = gpio_nand_get_config(dev, &gpiomtd->plat);
+ ret = gpio_nand_get_config(dev, chip);
if (ret)
return ret;
@@ -349,7 +306,6 @@ static int gpio_nand_probe(struct platform_device *pdev)
gpiomtd->base.ops = &gpio_nand_ops;
nand_set_flash_node(chip, pdev->dev.of_node);
- chip->options = gpiomtd->plat.options;
chip->controller = &gpiomtd->base;
mtd = nand_to_mtd(chip);
@@ -372,11 +328,7 @@ static int gpio_nand_probe(struct platform_device *pdev)
if (ret)
goto err_wp;
- if (gpiomtd->plat.adjust_parts)
- gpiomtd->plat.adjust_parts(&gpiomtd->plat, mtd->size);
-
- ret = mtd_device_register(mtd, gpiomtd->plat.parts,
- gpiomtd->plat.num_parts);
+ ret = mtd_device_register(mtd, NULL, 0);
if (!ret)
return 0;
@@ -395,7 +347,7 @@ static struct platform_driver gpio_nand_driver = {
.remove_new = gpio_nand_remove,
.driver = {
.name = "gpio-nand",
- .of_match_table = of_match_ptr(gpio_nand_id_table),
+ .of_match_table = gpio_nand_id_table,
},
};