| Message ID | 20240414065305.9796-1-marco@sirabella.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Documentation: spi: Update gpio+bitbang instruction | expand |
Hi, On Sun, 14 Apr 2024 at 08:54, Marco Sirabella <marco@sirabella.org> wrote: > > The way to do this was changed in > 9b00bc7b901f (spi-gpio: Rewrite to use GPIO descriptors) > and there's no real docs outlining this, > update defunct #include "spi-gpio.c" instructions > > Signed-off-by: Marco Sirabella <marco@sirabella.org> > --- > drivers/spi/spi-gpio.c | 17 ++++------------- > 1 file changed, 4 insertions(+), 13 deletions(-) > > diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c > index 909cce109bba..8c5f88f01db2 100644 > --- a/drivers/spi/spi-gpio.c > +++ b/drivers/spi/spi-gpio.c > @@ -44,22 +44,13 @@ struct spi_gpio { > * per transferred bit can make performance a problem, this code > * is set up so that you can use it in either of two ways: > * > - * - The slow generic way: set up platform_data to hold the GPIO > + * - The generic way: set up platform_data to hold the GPIO > * numbers used for MISO/MOSI/SCK, and issue procedure calls for > * each of them. This driver can handle several such busses. 9b00bc7b901f (spi-gpio: Rewrite to use GPIO descriptors) removed the fields for the GPIO numbers, so this is definitely not the way anymore. Since the code now always uses descriptors, the performance comment in the first paragraph does not apply anymore as well and should be dropped as well. > * > - * - The quicker inlined way: only helps with platform GPIO code > - * that inlines operations for constant GPIOs. This can give > - * you tight (fast!) inner loops, but each such bus needs a > - * new driver. You'll define a new C file, with Makefile and > - * Kconfig support; the C code can be a total of six lines: > - * > - * #define DRIVER_NAME "myboard_spi2" > - * #define SPI_MISO_GPIO 119 > - * #define SPI_MOSI_GPIO 120 > - * #define SPI_SCK_GPIO 121 > - * #define SPI_N_CHIPSEL 4 > - * #include "spi-gpio.c" > + * - The inlined way: manually set up and register a gpiod_lookup_table with > + * the appropriately labelled gpio pins "sck", "mosi", "miso" & an array > + * named "cs" before calling devm_spi_register_controller (XXX). I think you need to use platform_device_register(), at least both remaining users do so. And this is AFAICT now the only option for registering it via C code (which also means that DRIVER_NAME will never be defined from outside, and GENERIC_BITBANG will always be true ... ). Best Regards, Jonas
diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index 909cce109bba..8c5f88f01db2 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -44,22 +44,13 @@ struct spi_gpio { * per transferred bit can make performance a problem, this code * is set up so that you can use it in either of two ways: * - * - The slow generic way: set up platform_data to hold the GPIO + * - The generic way: set up platform_data to hold the GPIO * numbers used for MISO/MOSI/SCK, and issue procedure calls for * each of them. This driver can handle several such busses. * - * - The quicker inlined way: only helps with platform GPIO code - * that inlines operations for constant GPIOs. This can give - * you tight (fast!) inner loops, but each such bus needs a - * new driver. You'll define a new C file, with Makefile and - * Kconfig support; the C code can be a total of six lines: - * - * #define DRIVER_NAME "myboard_spi2" - * #define SPI_MISO_GPIO 119 - * #define SPI_MOSI_GPIO 120 - * #define SPI_SCK_GPIO 121 - * #define SPI_N_CHIPSEL 4 - * #include "spi-gpio.c" + * - The inlined way: manually set up and register a gpiod_lookup_table with + * the appropriately labelled gpio pins "sck", "mosi", "miso" & an array + * named "cs" before calling devm_spi_register_controller (XXX). */ #ifndef DRIVER_NAME
The way to do this was changed in 9b00bc7b901f (spi-gpio: Rewrite to use GPIO descriptors) and there's no real docs outlining this, update defunct #include "spi-gpio.c" instructions Signed-off-by: Marco Sirabella <marco@sirabella.org> --- drivers/spi/spi-gpio.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-)