--- /dev/null
+/*
+ * (C) Copyright 2010
+ * Michael Kurz <michi.kurz@googlemail.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+
+#include <asm/addrspace.h>
+#include <asm/types.h>
+#include <asm/ar71xx.h>
+
+/*-----------------------------------------------------------------------
+ * Definitions
+ */
+
+#ifdef DEBUG_SPI
+#define PRINTD(fmt,args...) printf (fmt ,##args)
+#else
+#define PRINTD(fmt,args...)
+#endif
+
+struct ar71xx_spi_slave {
+ struct spi_slave slave;
+ unsigned int mode;
+};
+
+static inline struct ar71xx_spi_slave *to_ar71xx_spi(struct spi_slave *slave)
+{
+ return container_of(slave, struct ar71xx_spi_slave, slave);
+}
+
+/*=====================================================================*/
+/* Public Functions */
+/*=====================================================================*/
+
+/*-----------------------------------------------------------------------
+ * Initialization
+ */
+
+void spi_init()
+{
+ PRINTD("ar71xx_spi: spi_init");
+
+ // Init SPI Hardware, disable remap, set clock
+ __raw_writel(0x43, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_CTRL));
+
+ PRINTD(" ---> out\n");
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct ar71xx_spi_slave *ss;
+
+ PRINTD("ar71xx_spi: spi_setup_slave");
+
+ if ((bus != 0) || (cs > 2))
+ return NULL;
+
+ ss = malloc(sizeof(struct ar71xx_spi_slave));
+ if (!ss)
+ return NULL;
+
+ ss->slave.bus = bus;
+ ss->slave.cs = cs;
+ ss->mode = mode;
+
+ /* TODO: Use max_hz to limit the SCK rate */
+
+ PRINTD(" ---> out\n");
+
+ return &ss->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct ar71xx_spi_slave *ss = to_ar71xx_spi(slave);
+
+ free(ss);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+ void *din, unsigned long flags)
+{
+ struct ar71xx_spi_slave *ss = to_ar71xx_spi(slave);
+ uint8_t *rx = din;
+ const uint8_t *tx = dout;
+ uint8_t curbyte, curbitlen, restbits;
+ uint32_t bytes = bitlen / 8;
+ uint32_t out;
+ uint32_t in;
+
+ PRINTD("ar71xx_spi: spi_xfer: slave:%p bitlen:%08x dout:%p din:%p flags:%08x\n", slave, bitlen, dout, din, flags);
+
+ if (flags & SPI_XFER_BEGIN) {
+ __raw_writel(SPI_FS_GPIO, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_FS));
+ __raw_writel(SPI_IOC_CS_ALL, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC));
+ }
+
+ restbits = (bitlen % 8);
+ if (restbits != 0)
+ bytes++;
+
+ // enable chip select
+ out = SPI_IOC_CS_ALL & ~(SPI_IOC_CS(slave->cs));
+
+ while (bytes--) {
+
+ curbyte = 0;
+ if (tx) {
+ curbyte = *tx++;
+ }
+
+ if (restbits != 0) {
+ curbitlen = restbits;
+ curbyte <<= 8 - restbits;
+ } else {
+ curbitlen = 8;
+ }
+
+ PRINTD("ar71xx_spi: sending: data:%02x length:%d\n", curbyte, curbitlen);
+
+ /* clock starts at inactive polarity */
+ for (curbyte <<= (8 - curbitlen); curbitlen; curbitlen--) {
+
+ if (curbyte & (1 << 7))
+ out |= SPI_IOC_DO;
+ else
+ out &= ~(SPI_IOC_DO);
+
+ /* setup MSB (to slave) on trailing edge */
+ __raw_writel(out, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC));
+
+ __raw_writel(out | SPI_IOC_CLK, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC));
+
+ curbyte <<= 1;
+ }
+
+ in = __raw_readl(KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_RDS));
+ PRINTD("ar71xx_spi: received:%02x\n", in);
+
+ if (rx) {
+ if (restbits == 0) {
+ *rx++ = in;
+ } else {
+ *rx++ = (in << (8 - restbits));
+ }
+ }
+ }
+
+ if (flags & SPI_XFER_END) {
+ __raw_writel(SPI_IOC_CS(slave->cs), KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC));
+ __raw_writel(SPI_IOC_CS_ALL, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_IOC));
+ __raw_writel(0, KSEG1ADDR(AR71XX_SPI_BASE + SPI_REG_FS));
+ }
+
+ PRINTD(" ---> out\n");
+
+ return 0;
+}
projects / openwrt.git / blobdiff