[U-Boot] [PATCH 1/2] spi: microblaze: Adds driver for Xilinx SPI controller
Stephan Linz
linz at li-pro.net
Sun Jul 29 00:25:35 CEST 2012
This is an improved version of the driver patch original
submitted by Graeme Smecher <graeme.smecher at 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 at 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 at wytron.com.tw>
+ * Copyright (c) 2010 Graeme Smecher <graeme.smecher at mail.mcgill.ca>
+ * Copyright (c) 2012 Stephan Linz <linz at 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 at wytron.com.tw>
+ * Copyright (c) 2010 Graeme Smecher <graeme.smecher at mail.mcgill.ca>
+ * Copyright (c) 2012 Stephan Linz <linz at 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_ */
--
1.7.0.4
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