This is an improved version of the driver patch original submitted by Graeme Smecher graeme.smecher@mail.mcgill.ca

The changes are: - remove hard coded Xilinx BSP defines (XPAR_SPI_*) and use CONFIG_SYS_SPI_BASE from config.h instead - add extensive register struct definitions - remove offset calculation for register access and use the new register struct instead - move default SPI controller configuration from spi_setup_slave() to spi_claim_bus() - add spi_set_speed() - insert SPI controller deactivation in spi_release_bus() - protect while loops in spi_xfer() with counter / timeouts - support SPI mode flags: LSB_FIRST, CPHA, CPOL, LOOP

Come from: http://patchwork.ozlabs.org/patch/71797/

Signed-off-by: Stephan Linz linz@li-pro.net --- v2: Remove useles information from commit message Add newline and split variable declaration from code --- drivers/spi/Makefile | 1 + drivers/spi/xilinx_spi.c | 214 ++++++++++++++++++++++++++++++++++++++++++++++ drivers/spi/xilinx_spi.h | 135 +++++++++++++++++++++++++++++ 3 files changed, 350 insertions(+), 0 deletions(-) create mode 100644 drivers/spi/xilinx_spi.c create mode 100644 drivers/spi/xilinx_spi.h

diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index c967d87..3ae38e5 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -44,6 +44,7 @@ COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o COBJS-$(CONFIG_SH_SPI) += sh_spi.o COBJS-$(CONFIG_FSL_ESPI) += fsl_espi.o COBJS-$(CONFIG_TEGRA2_SPI) += tegra2_spi.o +COBJS-$(CONFIG_XILINX_SPI) += xilinx_spi.o

COBJS := $(COBJS-y) SRCS := $(COBJS:.o=.c) diff --git a/drivers/spi/xilinx_spi.c b/drivers/spi/xilinx_spi.c new file mode 100644 index 0000000..e563c19 --- /dev/null +++ b/drivers/spi/xilinx_spi.c @@ -0,0 +1,214 @@ +/* + * Xilinx SPI driver + * + * supports 8 bit SPI transfers only, with or w/o FIFO + * + * based on bfin_spi.c, by way of altera_spi.c + * Copyright (c) 2005-2008 Analog Devices Inc. + * Copyright (c) 2010 Thomas Chou thomas@wytron.com.tw + * Copyright (c) 2010 Graeme Smecher graeme.smecher@mail.mcgill.ca + * Copyright (c) 2012 Stephan Linz linz@li-pro.net + * + * Licensed under the GPL-2 or later. + * + * [0]: http://www.xilinx.com/support/documentation + * + * [S]: [0]/ip_documentation/xps_spi.pdf + * [0]/ip_documentation/axi_spi_ds742.pdf + */ +#include <config.h> +#include <common.h> +#include <malloc.h> +#include <spi.h> + +#include "xilinx_spi.h" + +#ifndef CONFIG_SYS_XILINX_SPI_LIST +#define CONFIG_SYS_XILINX_SPI_LIST { CONFIG_SYS_SPI_BASE } +#endif + +#ifndef CONFIG_XILINX_SPI_IDLE_VAL +#define CONFIG_XILINX_SPI_IDLE_VAL 0xff +#endif + +#define XILSPI_SPICR_DFLT_ON (SPICR_MANUAL_SS | \ + SPICR_MASTER_MODE | \ + SPICR_SPE) + +#define XILSPI_SPICR_DFLT_OFF (SPICR_MASTER_INHIBIT | \ + SPICR_MANUAL_SS) + +#define XILSPI_MAX_XFER_BITS 8 + +static unsigned long xilinx_spi_base_list[] = CONFIG_SYS_XILINX_SPI_LIST; + +__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(SPISSR_ACT(slave->cs), &xilspi->regs->spissr); +} + +__attribute__((weak)) +void spi_cs_deactivate(struct spi_slave *slave) +{ + struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave); + + writel(SPISSR_OFF, &xilspi->regs->spissr); +} + +void spi_init(void) +{ + /* do nothing */ +} + +void spi_set_speed(struct spi_slave *slave, uint hz) +{ + /* xilinx spi core does not support programmable speed */ +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct xilinx_spi_slave *xilspi; + struct xilinx_spi_reg *regs; + + if (!spi_cs_is_valid(bus, cs)) { + printf("XILSPI error: %s: unsupported bus %d / cs %d\n", + __func__, bus, cs); + return NULL; + } + + xilspi = malloc(sizeof(*xilspi)); + if (!xilspi) { + printf("XILSPI error: %s: malloc of SPI structure failed\n", + __func__); + return NULL; + } + xilspi->slave.bus = bus; + xilspi->slave.cs = cs; + xilspi->regs = (struct xilinx_spi_reg *)xilinx_spi_base_list[bus]; + xilspi->freq = max_hz; + xilspi->mode = mode; + debug("%s: bus:%i cs:%i base:%p mode:%x max_hz:%d\n", __func__, + bus, cs, xilspi->regs, xilspi->mode, xilspi->freq); + + 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); + u32 spicr; + + debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs); + writel(SPISSR_OFF, &xilspi->regs->spissr); + + spicr = XILSPI_SPICR_DFLT_ON; + if (xilspi->mode & SPI_LSB_FIRST) + spicr |= SPICR_LSB_FIRST; + if (xilspi->mode & SPI_CPHA) + spicr |= SPICR_CPHA; + if (xilspi->mode & SPI_CPOL) + spicr |= SPICR_CPOL; + if (xilspi->mode & SPI_LOOP) + spicr |= SPICR_LOOP; + + writel(spicr, &xilspi->regs->spicr); + 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(SPISSR_OFF, &xilspi->regs->spissr); + writel(XILSPI_SPICR_DFLT_OFF, &xilspi->regs->spicr); +} + +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 */ + unsigned int bytes = bitlen / XILSPI_MAX_XFER_BITS; + const unsigned char *txp = dout; + unsigned char *rxp = din; + unsigned rxecount = 17; /* max. 16 elements in FIFO, leftover 1 */ + + 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 % XILSPI_MAX_XFER_BITS) { + printf("XILSPI warning: %s: Not a multiple of %d bits\n", + __func__, XILSPI_MAX_XFER_BITS); + flags |= SPI_XFER_END; + goto done; + } + + /* empty read buffer */ + while (rxecount && !(readl(&xilspi->regs->spisr) & SPISR_RX_EMPTY)) { + readl(&xilspi->regs->spidrr); + rxecount--; + } + + if (!rxecount) { + printf("XILSPI error: %s: Rx buffer not empty\n", __func__); + return -1; + } + + if (flags & SPI_XFER_BEGIN) + spi_cs_activate(slave); + + while (bytes--) { + unsigned timeout = /* at least 1usec or greater, leftover 1 */ + xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 : + (XILSPI_MAX_XFER_BITS * 1000000 / xilspi->freq) + 1; + + /* get Tx element from data out buffer and count up */ + unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL; + debug("%s: tx:%x ", __func__, d); + + /* write out and wait for processing (receive data) */ + writel(d & SPIDTR_8BIT_MASK, &xilspi->regs->spidtr); + while (timeout && readl(&xilspi->regs->spisr) + & SPISR_RX_EMPTY) { + timeout--; + udelay(1); + } + + if (!timeout) { + printf("XILSPI error: %s: Xfer timeout\n", __func__); + return -1; + } + + /* read Rx element and push into data in buffer */ + d = readl(&xilspi->regs->spidrr) & SPIDRR_8BIT_MASK; + if (rxp) + *rxp++ = d; + debug("rx:%x\n", d); + } + + done: + if (flags & SPI_XFER_END) + spi_cs_deactivate(slave); + + return 0; +} diff --git a/drivers/spi/xilinx_spi.h b/drivers/spi/xilinx_spi.h new file mode 100644 index 0000000..32610d2 --- /dev/null +++ b/drivers/spi/xilinx_spi.h @@ -0,0 +1,135 @@ +/* + * Xilinx SPI driver + * + * XPS/AXI bus interface + * + * based on bfin_spi.c, by way of altera_spi.c + * Copyright (c) 2005-2008 Analog Devices Inc. + * Copyright (c) 2010 Thomas Chou thomas@wytron.com.tw + * Copyright (c) 2010 Graeme Smecher graeme.smecher@mail.mcgill.ca + * Copyright (c) 2012 Stephan Linz linz@li-pro.net + * + * Licensed under the GPL-2 or later. + * + * [0]: http://www.xilinx.com/support/documentation + * + * [S]: [0]/ip_documentation/xps_spi.pdf + * [0]/ip_documentation/axi_spi_ds742.pdf + */ +#ifndef _XILINX_SPI_ +#define _XILINX_SPI_ + +#include <asm/types.h> +#include <asm/io.h> + +/* + * Xilinx SPI Register Definition + * + * [1]: [0]/ip_documentation/xps_spi.pdf + * page 8, Register Descriptions + * [2]: [0]/ip_documentation/axi_spi_ds742.pdf + * page 7, Register Overview Table + */ +struct xilinx_spi_reg { + u32 __space0__[7]; + u32 dgier; /* Device Global Interrupt Enable Register (DGIER) */ + u32 ipisr; /* IP Interrupt Status Register (IPISR) */ + u32 __space1__; + u32 ipier; /* IP Interrupt Enable Register (IPIER) */ + u32 __space2__[5]; + u32 srr; /* Softare Reset Register (SRR) */ + u32 __space3__[7]; + u32 spicr; /* SPI Control Register (SPICR) */ + u32 spisr; /* SPI Status Register (SPISR) */ + u32 spidtr; /* SPI Data Transmit Register (SPIDTR) */ + u32 spidrr; /* SPI Data Receive Register (SPIDRR) */ + u32 spissr; /* SPI Slave Select Register (SPISSR) */ + u32 spitfor; /* SPI Transmit FIFO Occupancy Register (SPITFOR) */ + u32 spirfor; /* SPI Receive FIFO Occupancy Register (SPIRFOR) */ +}; + +/* Device Global Interrupt Enable Register (dgier), [1] p15, [2] p15 */ +#define DGIER_GIE (1 << 31) + +/* IP Interrupt Status Register (ipisr), [1] p15, [2] p15 */ +#define IPISR_DRR_NOT_EMPTY (1 << 8) +#define IPISR_SLAVE_SELECT (1 << 7) +#define IPISR_TXF_HALF_EMPTY (1 << 6) +#define IPISR_DRR_OVERRUN (1 << 5) +#define IPISR_DRR_FULL (1 << 4) +#define IPISR_DTR_UNDERRUN (1 << 3) +#define IPISR_DTR_EMPTY (1 << 2) +#define IPISR_SLAVE_MODF (1 << 1) +#define IPISR_MODF (1 << 0) + +/* IP Interrupt Enable Register (ipier), [1] p17, [2] p18 */ +#define IPIER_DRR_NOT_EMPTY (1 << 8) +#define IPIER_SLAVE_SELECT (1 << 7) +#define IPIER_TXF_HALF_EMPTY (1 << 6) +#define IPIER_DRR_OVERRUN (1 << 5) +#define IPIER_DRR_FULL (1 << 4) +#define IPIER_DTR_UNDERRUN (1 << 3) +#define IPIER_DTR_EMPTY (1 << 2) +#define IPIER_SLAVE_MODF (1 << 1) +#define IPIER_MODF (1 << 0) + +/* Softare Reset Register (srr), [1] p9, [2] p8 */ +#define SRR_RESET_CODE 0x0000000A + +/* SPI Control Register (spicr), [1] p9, [2] p8 */ +#define SPICR_LSB_FIRST (1 << 9) +#define SPICR_MASTER_INHIBIT (1 << 8) +#define SPICR_MANUAL_SS (1 << 7) +#define SPICR_RXFIFO_RESEST (1 << 6) +#define SPICR_TXFIFO_RESEST (1 << 5) +#define SPICR_CPHA (1 << 4) +#define SPICR_CPOL (1 << 3) +#define SPICR_MASTER_MODE (1 << 2) +#define SPICR_SPE (1 << 1) +#define SPICR_LOOP (1 << 0) + +/* SPI Status Register (spisr), [1] p11, [2] p10 */ +#define SPISR_SLAVE_MODE_SELECT (1 << 5) +#define SPISR_MODF (1 << 4) +#define SPISR_TX_FULL (1 << 3) +#define SPISR_TX_EMPTY (1 << 2) +#define SPISR_RX_FULL (1 << 1) +#define SPISR_RX_EMPTY (1 << 0) + +/* SPI Data Transmit Register (spidtr), [1] p12, [2] p12 */ +#define SPIDTR_8BIT_MASK (0xff << 0) +#define SPIDTR_16BIT_MASK (0xffff << 0) +#define SPIDTR_32BIT_MASK (0xffffffff << 0) + +/* SPI Data Receive Register (spidrr), [1] p12, [2] p12 */ +#define SPIDRR_8BIT_MASK (0xff << 0) +#define SPIDRR_16BIT_MASK (0xffff << 0) +#define SPIDRR_32BIT_MASK (0xffffffff << 0) + +/* SPI Slave Select Register (spissr), [1] p13, [2] p13 */ +#define SPISSR_MASK(cs) (1 << (cs)) +#define SPISSR_ACT(cs) ~SPISSR_MASK(cs) +#define SPISSR_OFF ~0UL + +/* SPI Transmit FIFO Occupancy Register (spitfor), [1] p13, [2] p14 */ +#define SPITFOR_OCYVAL_POS 0 +#define SPITFOR_OCYVAL_MASK (0xf << SPITFOR_OCYVAL_POS) + +/* SPI Receive FIFO Occupancy Register (spirfor), [1] p14, [2] p14 */ +#define SPIRFOR_OCYVAL_POS 0 +#define SPIRFOR_OCYVAL_MASK (0xf << SPIRFOR_OCYVAL_POS) + +struct xilinx_spi_slave { + struct spi_slave slave; + struct xilinx_spi_reg *regs; + unsigned int freq; + unsigned int mode; +}; + +static inline struct xilinx_spi_slave *to_xilinx_spi_slave( + struct spi_slave *slave) +{ + return container_of(slave, struct xilinx_spi_slave, slave); +} + +#endif /* _XILINX_SPI_ */