[U-Boot] [PATCH] Adds driver for Xilinx' xps_spi SPI controller
Graeme Smecher
graeme.smecher at mail.mcgill.ca
Tue Jul 27 16:02:22 CEST 2010
Hi all,
I neglected to point out that this driver has been tested with Thomas
Chou's mmc_spi patches, and appears to work with SPI flash (Winbond
w25q64) as well.
A quick diff shows this driver is nearly identical to the altera_spi
driver. The only differences are:
* the CS register is active-low here, and
* the control register requires some additional setup.
cheers,
Graeme Smecher
On 10-07-27 09:56 AM, Graeme Smecher wrote:
> ---
> drivers/spi/Makefile | 1 +
> drivers/spi/xilinx_spi.c | 171 ++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 172 insertions(+), 0 deletions(-)
> create mode 100644 drivers/spi/xilinx_spi.c
>
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index dfcbb8b..34e0f31 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -26,6 +26,7 @@ include $(TOPDIR)/config.mk
> LIB := $(obj)libspi.a
>
> COBJS-$(CONFIG_ALTERA_SPI) += altera_spi.o
> +COBJS-$(CONFIG_XILINX_SPI) += xilinx_spi.o
> COBJS-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o
> COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
> COBJS-$(CONFIG_BFIN_SPI) += bfin_spi.o
> diff --git a/drivers/spi/xilinx_spi.c b/drivers/spi/xilinx_spi.c
> new file mode 100644
> index 0000000..99ce661
> --- /dev/null
> +++ b/drivers/spi/xilinx_spi.c
> @@ -0,0 +1,171 @@
> +/*
> + * Xilinx SPI driver
> + *
> + * based on bfin_spi.c, by way of altera_spi.c
> + * Copyright (c) 2005-2008 Analog Devices Inc.
> + * Copyright (c) 2010 Thomas Chou<thomas at wytron.com.tw>
> + * Copyright (c) 2010 Graeme Smecher<graeme.smecher at mail.mcgill.ca>
> + *
> + * Licensed under the GPL-2 or later.
> + */
> +#include<common.h>
> +#include<asm/io.h>
> +#include<malloc.h>
> +#include<spi.h>
> +
> +#define debug printf
> +
> +#define XILINX_SPI_RR 0x6c
> +#define XILINX_SPI_TR 0x68
> +#define XILINX_SPI_SR 0x64
> +#define XILINX_SPI_CR 0x60
> +#define XILINX_SPI_SSR 0x70
> +
> +#define XILINX_SPI_SR_RX_EMPTY_MSK 0x01
> +
> +#define XILINX_SPI_CR_DEFAULT (0x0086)
> +
> +#if XPAR_XSPI_NUM_INSTANCES> 4
> +# warning "The xilinx_spi driver will ignore some of your SPI peripherals!"
> +#endif
> +
> +static ulong xilinx_spi_base_list[] = {
> +#ifdef XPAR_SPI_0_BASEADDR
> + XPAR_SPI_0_BASEADDR,
> +#endif
> +#ifdef XPAR_SPI_1_BASEADDR
> + XPAR_SPI_1_BASEADDR,
> +#endif
> +#ifdef XPAR_SPI_2_BASEADDR
> + XPAR_SPI_2_BASEADDR,
> +#endif
> +#ifdef XPAR_SPI_3_BASEADDR
> + XPAR_SPI_3_BASEADDR,
> +#endif
> +};
> +
> +struct xilinx_spi_slave {
> + struct spi_slave slave;
> + ulong base;
> +};
> +#define to_xilinx_spi_slave(s) container_of(s, struct xilinx_spi_slave, slave)
> +
> +__attribute__((weak))
> +int spi_cs_is_valid(unsigned int bus, unsigned int cs)
> +{
> + return bus< ARRAY_SIZE(xilinx_spi_base_list)&& cs< 32;
> +}
> +
> +__attribute__((weak))
> +void spi_cs_activate(struct spi_slave *slave)
> +{
> + struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
> + writel(~(1<< slave->cs), xilspi->base + XILINX_SPI_SSR);
> +}
> +
> +__attribute__((weak))
> +void spi_cs_deactivate(struct spi_slave *slave)
> +{
> + struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
> + writel(~0, xilspi->base + XILINX_SPI_SSR);
> +}
> +
> +void spi_init(void)
> +{
> +}
> +
> +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
> + unsigned int max_hz, unsigned int mode)
> +{
> + struct xilinx_spi_slave *xilspi;
> +
> + if (!spi_cs_is_valid(bus, cs))
> + return NULL;
> +
> + xilspi = malloc(sizeof(*xilspi));
> + if (!xilspi)
> + return NULL;
> +
> + xilspi->slave.bus = bus;
> + xilspi->slave.cs = cs;
> + xilspi->base = xilinx_spi_base_list[bus];
> + debug("%s: bus:%i cs:%i base:%lx\n", __func__,
> + bus, cs, xilspi->base);
> +
> + writel(XILINX_SPI_CR_DEFAULT, xilspi->base + XILINX_SPI_CR);
> +
> + return&xilspi->slave;
> +}
> +
> +void spi_free_slave(struct spi_slave *slave)
> +{
> + struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
> + free(xilspi);
> +}
> +
> +int spi_claim_bus(struct spi_slave *slave)
> +{
> + struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
> +
> + debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
> + writel(~0, xilspi->base + XILINX_SPI_SSR);
> + return 0;
> +}
> +
> +void spi_release_bus(struct spi_slave *slave)
> +{
> + struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
> +
> + debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
> + writel(~0, xilspi->base + XILINX_SPI_SSR);
> +}
> +
> +#ifndef CONFIG_XILINX_SPI_IDLE_VAL
> +# define CONFIG_XILINX_SPI_IDLE_VAL 0xff
> +#endif
> +
> +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
> + void *din, unsigned long flags)
> +{
> + struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
> + /* assume spi core configured to do 8 bit transfers */
> + uint bytes = bitlen / 8;
> + const uchar *txp = dout;
> + uchar *rxp = din;
> +
> + debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
> + slave->bus, slave->cs, bitlen, bytes, flags);
> + if (bitlen == 0)
> + goto done;
> +
> + if (bitlen % 8) {
> + flags |= SPI_XFER_END;
> + goto done;
> + }
> +
> + /* empty read buffer */
> + while (!(readl(xilspi->base + XILINX_SPI_SR)&
> + XILINX_SPI_SR_RX_EMPTY_MSK))
> + readl(xilspi->base + XILINX_SPI_RR);
> +
> + if (flags& SPI_XFER_BEGIN)
> + spi_cs_activate(slave);
> +
> + while (bytes--) {
> + uchar d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL;
> + debug("%s: tx:%x ", __func__, d);
> + writel(d, xilspi->base + XILINX_SPI_TR);
> + while (readl(xilspi->base + XILINX_SPI_SR)&
> + XILINX_SPI_SR_RX_EMPTY_MSK)
> + ;
> + d = readl(xilspi->base + XILINX_SPI_RR);
> + if (rxp)
> + *rxp++ = d;
> + debug("rx:%x\n", d);
> + }
> + done:
> + if (flags& SPI_XFER_END)
> + spi_cs_deactivate(slave);
> +
> + return 0;
> +}
More information about the U-Boot
mailing list