From ba6c3ce9bd0ac572592dc909878117dce219c564 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Mon, 11 Mar 2013 06:08:00 +0000 Subject: spi: Add function to allocate a new SPI slave At present it is difficult to extend the SPI structure since all drivers allocate it themselves, and few of them zero all fields. Add a new function spi_alloc_slave() which can be used by SPI drivers to perform this allocation, and thus ensure that all drivers can better cope with SPI structure changes. Signed-off-by: Simon Glass --- include/spi.h | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) (limited to 'include/spi.h') diff --git a/include/spi.h b/include/spi.h index 60e85db..ebc9652 100644 --- a/include/spi.h +++ b/include/spi.h @@ -62,6 +62,47 @@ struct spi_slave { */ void spi_init(void); +/** + * spi_do_alloc_slave - Allocate a new SPI slave (internal) + * + * Allocate and zero all fields in the spi slave, and set the bus/chip + * select. Use the helper macro spi_alloc_slave() to call this. + * + * @offset: Offset of struct spi_slave within slave structure + * @size: Size of slave structure + * @bus: Bus ID of the slave chip. + * @cs: Chip select ID of the slave chip on the specified bus. + */ +void *spi_do_alloc_slave(int offset, int size, unsigned int bus, + unsigned int cs); + +/** + * spi_alloc_slave - Allocate a new SPI slave + * + * Allocate and zero all fields in the spi slave, and set the bus/chip + * select. + * + * @_struct: Name of structure to allocate (e.g. struct tegra_spi). This + * structure must contain a member 'struct spi_slave *slave'. + * @bus: Bus ID of the slave chip. + * @cs: Chip select ID of the slave chip on the specified bus. + */ +#define spi_alloc_slave(_struct, bus, cs) \ + spi_do_alloc_slave(offsetof(_struct, slave), \ + sizeof(_struct), bus, cs) + +/** + * spi_alloc_slave_base - Allocate a new SPI slave with no private data + * + * Allocate and zero all fields in the spi slave, and set the bus/chip + * select. + * + * @bus: Bus ID of the slave chip. + * @cs: Chip select ID of the slave chip on the specified bus. + */ +#define spi_alloc_slave_base(bus, cs) \ + spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs) + /*----------------------------------------------------------------------- * Set up communications parameters for a SPI slave. * -- cgit v1.1 From 0c456cee952f3fa5ae6f5c42f960eeaa39140b62 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Mon, 11 Mar 2013 06:08:05 +0000 Subject: spi: Add parameter for maximum write size Some SPI controllers (e.g. Intel ICH) have a limit on the number of SPI bytes that can be written at a time. Add this as a parameter so that clients of the SPI interface can respect this value. Signed-off-by: Simon Glass --- include/spi.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/spi.h') diff --git a/include/spi.h b/include/spi.h index ebc9652..3fe2e1e 100644 --- a/include/spi.h +++ b/include/spi.h @@ -49,10 +49,13 @@ * * bus: ID of the bus that the slave is attached to. * cs: ID of the chip select connected to the slave. + * max_write_size: If non-zero, the maximum number of bytes which can + * be written at once, excluding command bytes. */ struct spi_slave { unsigned int bus; unsigned int cs; + unsigned int max_write_size; }; /*----------------------------------------------------------------------- -- cgit v1.1