mtd: rawnand: ams-delta: Make the driver custom I/O ready

In order to be merged with "gpio-nand", the driver must support custom
(non-GPIO) I/O accessors.

Allow platforms to omit data GPIO port as well as NWE pin info from
device setup.  For the driver to still work on such platform, custom
I/O accessors as well as a custom probe function which initialises the
driver private structure with those accessors must be added to the
driver.

Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200212003929.6682-14-jmkrzyszt@gmail.com
This commit is contained in:
Janusz Krzysztofik 2020-02-12 01:39:28 +01:00 committed by Miquel Raynal
parent edfd8d9c76
commit 2b1dcee304

View File

@ -43,6 +43,9 @@ struct ams_delta_nand {
bool data_in;
unsigned int tRP;
unsigned int tWP;
u8 (*io_read)(struct ams_delta_nand *this);
void (*io_write)(struct ams_delta_nand *this,
u8 byte);
};
static void ams_delta_write_commit(struct ams_delta_nand *priv)
@ -116,18 +119,18 @@ static void ams_delta_write_buf(struct ams_delta_nand *priv, const u8 *buf,
ams_delta_dir_output(priv, buf[i++]);
while (i < len)
ams_delta_io_write(priv, buf[i++]);
priv->io_write(priv, buf[i++]);
}
static void ams_delta_read_buf(struct ams_delta_nand *priv, u8 *buf, int len)
{
int i;
if (!priv->data_in)
if (priv->data_gpiods && !priv->data_in)
ams_delta_dir_input(priv);
for (i = 0; i < len; i++)
buf[i] = ams_delta_io_read(priv);
buf[i] = priv->io_read(priv);
}
static void ams_delta_ctrl_cs(struct ams_delta_nand *priv, bool assert)
@ -289,7 +292,8 @@ static int ams_delta_init(struct platform_device *pdev)
return err;
}
priv->gpiod_nwe = devm_gpiod_get(&pdev->dev, "nwe", GPIOD_OUT_LOW);
priv->gpiod_nwe = devm_gpiod_get_optional(&pdev->dev, "nwe",
GPIOD_OUT_LOW);
if (IS_ERR(priv->gpiod_nwe)) {
err = PTR_ERR(priv->gpiod_nwe);
dev_err(&pdev->dev, "NWE GPIO request failed (%d)\n", err);
@ -311,13 +315,24 @@ static int ams_delta_init(struct platform_device *pdev)
}
/* Request array of data pins, initialize them as input */
priv->data_gpiods = devm_gpiod_get_array(&pdev->dev, "data", GPIOD_IN);
priv->data_gpiods = devm_gpiod_get_array_optional(&pdev->dev, "data",
GPIOD_IN);
if (IS_ERR(priv->data_gpiods)) {
err = PTR_ERR(priv->data_gpiods);
dev_err(&pdev->dev, "data GPIO request failed: %d\n", err);
return err;
}
if (priv->data_gpiods) {
if (!priv->gpiod_nwe) {
dev_err(&pdev->dev,
"mandatory NWE pin not provided by platform\n");
return -ENODEV;
}
priv->io_read = ams_delta_io_read;
priv->io_write = ams_delta_io_write;
priv->data_in = true;
}
if (pdev->id_entry)
probe = (void *) pdev->id_entry->driver_data;
@ -328,6 +343,11 @@ static int ams_delta_init(struct platform_device *pdev)
if (err)
return err;
if (!priv->io_read || !priv->io_write) {
dev_err(&pdev->dev, "incomplete device configuration\n");
return -ENODEV;
}
/* Initialize the NAND controller object embedded in ams_delta_nand. */
priv->base.ops = &ams_delta_ops;
nand_controller_init(&priv->base);