drm/ssd130x: Use new regmap bulk write support to drop custom bus

Data writes for the ssd130x 4-wire SPI protocol need special handling, due
the Data/Command control (D/C) pin having to be toggled prior to the write.

The regmap API only allowed drivers to provide .reg_{read,write} callbacks
to do per register read/write, but didn't provide a way for drivers to do
the same for bulk read/writes.

For this reason, a custom regmap bus was used by the driver just to define
a bulk write callback that implements the D/C pin toggling. But the regmap
API has been extended to support defining bulk read/write handlers, so the
custom regmap bus is not needed anymore and could just be dropped.
Signed-off-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Acked-by: default avatarSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220618174338.2253021-1-javierm@redhat.com
parent 53618649
...@@ -18,11 +18,6 @@ struct ssd130x_spi_transport { ...@@ -18,11 +18,6 @@ struct ssd130x_spi_transport {
struct gpio_desc *dc; struct gpio_desc *dc;
}; };
static const struct regmap_config ssd130x_spi_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
};
/* /*
* The regmap bus .write handler, it is just a wrapper around spi_write() * The regmap bus .write handler, it is just a wrapper around spi_write()
* but toggling the Data/Command control pin (D/C#). Since for 4-wire SPI * but toggling the Data/Command control pin (D/C#). Since for 4-wire SPI
...@@ -56,17 +51,12 @@ static int ssd130x_spi_read(void *context, const void *reg, size_t reg_size, ...@@ -56,17 +51,12 @@ static int ssd130x_spi_read(void *context, const void *reg, size_t reg_size,
return -EOPNOTSUPP; return -EOPNOTSUPP;
} }
/* static const struct regmap_config ssd130x_spi_regmap_config = {
* A custom bus is needed due the special write that toggles a D/C# pin, .reg_bits = 8,
* another option could be to just have a .reg_write() callback but that .val_bits = 8,
* will prevent to do data writes in bulk.
*
* Once the regmap API is extended to support defining a bulk write handler
* in the struct regmap_config, this can be simplified and the bus dropped.
*/
static struct regmap_bus regmap_ssd130x_spi_bus = {
.write = ssd130x_spi_write, .write = ssd130x_spi_write,
.read = ssd130x_spi_read, .read = ssd130x_spi_read,
.can_multi_write = true,
}; };
static int ssd130x_spi_probe(struct spi_device *spi) static int ssd130x_spi_probe(struct spi_device *spi)
...@@ -90,8 +80,7 @@ static int ssd130x_spi_probe(struct spi_device *spi) ...@@ -90,8 +80,7 @@ static int ssd130x_spi_probe(struct spi_device *spi)
t->spi = spi; t->spi = spi;
t->dc = dc; t->dc = dc;
regmap = devm_regmap_init(dev, &regmap_ssd130x_spi_bus, t, regmap = devm_regmap_init(dev, NULL, t, &ssd130x_spi_regmap_config);
&ssd130x_spi_regmap_config);
if (IS_ERR(regmap)) if (IS_ERR(regmap))
return PTR_ERR(regmap); return PTR_ERR(regmap);
......
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