spi: add altera spi controller support

This patch adds the driver of altera spi controller, which is
used as epcs/spi flash controller. It also works with mmc_spi
driver.

This driver support more than one spi bus, with base list declared
#define CONFIG_SYS_ALTERA_SPI_LIST { BASE_0,BASE_1,... }

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Tested-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Scott McNutt <smcnutt@psyent.com>

drivers/spi/Makefile

@@ -25,6 +25,7 @@ include $(TOPDIR)/config.mk
 
 LIB	:= $(obj)libspi.a
 
+COBJS-$(CONFIG_ALTERA_SPI) += altera_spi.o
 COBJS-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o
 COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
 COBJS-$(CONFIG_BFIN_SPI) += bfin_spi.o

drivers/spi/altera_spi.c

@@ -0,0 +1,165 @@
+/*
+ * Altera SPI driver
+ *
+ * based on bfin_spi.c
+ * Copyright (c) 2005-2008 Analog Devices Inc.
+ * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
+ *
+ * Licensed under the GPL-2 or later.
+ */
+#include <common.h>
+#include <asm/io.h>
+#include <malloc.h>
+#include <spi.h>
+
+#define ALTERA_SPI_RXDATA	0
+#define ALTERA_SPI_TXDATA	4
+#define ALTERA_SPI_STATUS	8
+#define ALTERA_SPI_CONTROL	12
+#define ALTERA_SPI_SLAVE_SEL	20
+
+#define ALTERA_SPI_STATUS_ROE_MSK	(0x8)
+#define ALTERA_SPI_STATUS_TOE_MSK	(0x10)
+#define ALTERA_SPI_STATUS_TMT_MSK	(0x20)
+#define ALTERA_SPI_STATUS_TRDY_MSK	(0x40)
+#define ALTERA_SPI_STATUS_RRDY_MSK	(0x80)
+#define ALTERA_SPI_STATUS_E_MSK	(0x100)
+
+#define ALTERA_SPI_CONTROL_IROE_MSK	(0x8)
+#define ALTERA_SPI_CONTROL_ITOE_MSK	(0x10)
+#define ALTERA_SPI_CONTROL_ITRDY_MSK	(0x40)
+#define ALTERA_SPI_CONTROL_IRRDY_MSK	(0x80)
+#define ALTERA_SPI_CONTROL_IE_MSK	(0x100)
+#define ALTERA_SPI_CONTROL_SSO_MSK	(0x400)
+
+#ifndef CONFIG_SYS_ALTERA_SPI_LIST
+#define CONFIG_SYS_ALTERA_SPI_LIST { CONFIG_SYS_SPI_BASE }
+#endif
+
+static ulong altera_spi_base_list[] = CONFIG_SYS_ALTERA_SPI_LIST;
+
+struct altera_spi_slave {
+	struct spi_slave slave;
+	ulong base;
+};
+#define to_altera_spi_slave(s) container_of(s, struct altera_spi_slave, slave)
+
+__attribute__((weak))
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	return bus < ARRAY_SIZE(altera_spi_base_list) && cs < 32;
+}
+
+__attribute__((weak))
+void spi_cs_activate(struct spi_slave *slave)
+{
+	struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
+	writel(1 << slave->cs, altspi->base + ALTERA_SPI_SLAVE_SEL);
+	writel(ALTERA_SPI_CONTROL_SSO_MSK, altspi->base + ALTERA_SPI_CONTROL);
+}
+
+__attribute__((weak))
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+	struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
+	writel(0, altspi->base + ALTERA_SPI_CONTROL);
+	writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL);
+}
+
+void spi_init(void)
+{
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+				  unsigned int max_hz, unsigned int mode)
+{
+	struct altera_spi_slave *altspi;
+
+	if (!spi_cs_is_valid(bus, cs))
+		return NULL;
+
+	altspi = malloc(sizeof(*altspi));
+	if (!altspi)
+		return NULL;
+
+	altspi->slave.bus = bus;
+	altspi->slave.cs = cs;
+	altspi->base = altera_spi_base_list[bus];
+	debug("%s: bus:%i cs:%i base:%lx\n", __func__,
+		bus, cs, altspi->base);
+
+	return &altspi->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
+	free(altspi);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+	struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
+
+	debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
+	writel(0, altspi->base + ALTERA_SPI_CONTROL);
+	writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL);
+	return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
+
+	debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
+	writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL);
+}
+
+#ifndef CONFIG_ALTERA_SPI_IDLE_VAL
+# define CONFIG_ALTERA_SPI_IDLE_VAL 0xff
+#endif
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+	     void *din, unsigned long flags)
+{
+	struct altera_spi_slave *altspi = to_altera_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 */
+	if (readl(altspi->base + ALTERA_SPI_STATUS) &
+	    ALTERA_SPI_STATUS_RRDY_MSK)
+		readl(altspi->base + ALTERA_SPI_RXDATA);
+	if (flags & SPI_XFER_BEGIN)
+		spi_cs_activate(slave);
+
+	while (bytes--) {
+		uchar d = txp ? *txp++ : CONFIG_ALTERA_SPI_IDLE_VAL;
+		debug("%s: tx:%x ", __func__, d);
+		writel(d, altspi->base + ALTERA_SPI_TXDATA);
+		while (!(readl(altspi->base + ALTERA_SPI_STATUS) &
+			 ALTERA_SPI_STATUS_RRDY_MSK))
+			;
+		d = readl(altspi->base + ALTERA_SPI_RXDATA);
+		if (rxp)
+			*rxp++ = d;
+		debug("rx:%x\n", d);
+	}
+ done:
+	if (flags & SPI_XFER_END)
+		spi_cs_deactivate(slave);
+
+	return 0;
+}