[U-Boot] [PATCH] Adds driver for Xilinx' xps_spi SPI controller
Graeme Smecher
graeme.smecher at mail.mcgill.ca
Tue Jul 27 15:56:10 CEST 2010
---
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;
+}
--
1.6.3.3
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