| Message ID | 20220618174338.2253021-1-javierm@redhat.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | drm/ssd130x: Use new regmap bulk write support to drop custom bus | expand |
Hi Javier, On Sat, Jun 18, 2022 at 07:43:38PM +0200, Javier Martinez Canillas wrote: > 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: Javier Martinez Canillas <javierm@redhat.com> Patch looks good, but obviously needs the dependencies sorted out. Acked-by: Sam Ravnborg <sam@ravnborg.org> Sam
Hello Sam, On 6/24/22 21:37, Sam Ravnborg wrote: > Hi Javier, > > On Sat, Jun 18, 2022 at 07:43:38PM +0200, Javier Martinez Canillas wrote: >> 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: Javier Martinez Canillas <javierm@redhat.com> > Patch looks good, but obviously needs the dependencies sorted out. > Acked-by: Sam Ravnborg <sam@ravnborg.org> > Thanks. The regmap fixes that were the dependencies landed in v5.19-rc4 and drm-misc-next is already at v5.19-rc6, so I'll push this patch now.
diff --git a/drivers/gpu/drm/solomon/ssd130x-spi.c b/drivers/gpu/drm/solomon/ssd130x-spi.c index 43722adab1f8..72f066ccd2d9 100644 --- a/drivers/gpu/drm/solomon/ssd130x-spi.c +++ b/drivers/gpu/drm/solomon/ssd130x-spi.c @@ -18,11 +18,6 @@ struct ssd130x_spi_transport { 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() * 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, return -EOPNOTSUPP; } -/* - * A custom bus is needed due the special write that toggles a D/C# pin, - * another option could be to just have a .reg_write() callback but that - * 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 = { +static const struct regmap_config ssd130x_spi_regmap_config = { + .reg_bits = 8, + .val_bits = 8, .write = ssd130x_spi_write, .read = ssd130x_spi_read, + .can_multi_write = true, }; 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->dc = dc; - regmap = devm_regmap_init(dev, ®map_ssd130x_spi_bus, t, - &ssd130x_spi_regmap_config); + regmap = devm_regmap_init(dev, NULL, t, &ssd130x_spi_regmap_config); if (IS_ERR(regmap)) return PTR_ERR(regmap);
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: Javier Martinez Canillas <javierm@redhat.com> --- This patch depends on the following regmap fixes: https://lkml.org/lkml/2022/6/16/198 drivers/gpu/drm/solomon/ssd130x-spi.c | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-)