andes_spi: add andes_spi interface

andes_spi is an spi interface developed by Andes Tech.

Signed-off-by: Macpaul Lin <macpaul@andestech.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Mike Frysinger <vapier@gentoo.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>

drivers/spi/Makefile

@@ -26,6 +26,7 @@ include $(TOPDIR)/config.mk
 LIB	:= $(obj)libspi.o
 
 COBJS-$(CONFIG_ALTERA_SPI) += altera_spi.o
+COBJS-$(CONFIG_ANDES_SPI) += andes_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/andes_spi.c

@@ -0,0 +1,302 @@
+/*
+ * Driver of Andes SPI Controller
+ *
+ * (C) Copyright 2011 Andes Technology
+ * Macpaul Lin <macpaul@andestech.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/io.h>
+#include "andes_spi.h"
+
+void spi_init(void)
+{
+	/* do nothing */
+}
+
+static void andes_spi_spit_en(struct andes_spi_slave *ds)
+{
+	unsigned int dcr = readl(&ds->regs->dcr);
+
+	debug("%s: dcr: %x, write value: %x\n",
+			__func__, dcr, (dcr | ANDES_SPI_DCR_SPIT));
+
+	writel((dcr | ANDES_SPI_DCR_SPIT), &ds->regs->dcr);
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+			unsigned int max_hz, unsigned int mode)
+{
+	struct andes_spi_slave	*ds;
+
+	if (!spi_cs_is_valid(bus, cs))
+		return NULL;
+
+	ds = malloc(sizeof(*ds));
+	if (!ds)
+		return NULL;
+
+	ds->slave.bus = bus;
+	ds->slave.cs = cs;
+	ds->regs = (struct andes_spi_regs *)CONFIG_SYS_SPI_BASE;
+
+	/*
+	 * The hardware of andes_spi will set its frequency according
+	 * to APB/AHB bus clock. Hence the hardware doesn't allow changing of
+	 * requency and so the user requested speed is always ignored.
+	 */
+	ds->freq = max_hz;
+
+	return &ds->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	struct andes_spi_slave *ds = to_andes_spi(slave);
+
+	free(ds);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+	struct andes_spi_slave *ds = to_andes_spi(slave);
+	unsigned int apb;
+	unsigned int baud;
+
+	/* Enable the SPI hardware */
+	writel(ANDES_SPI_CR_SPIRST, &ds->regs->cr);
+	udelay(1000);
+
+	/* setup format */
+	baud = ((CONFIG_SYS_CLK_FREQ / CONFIG_SYS_SPI_CLK / 2) - 1) & 0xFF;
+
+	/*
+	 * SPI_CLK = AHB bus clock / ((BAUD + 1)*2)
+	 * BAUD = AHB bus clock / SPI_CLK / 2) - 1
+	 */
+	apb = (readl(&ds->regs->apb) & 0xffffff00) | baud;
+	writel(apb, &ds->regs->apb);
+
+	/* no interrupts */
+	writel(0, &ds->regs->ie);
+
+	return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	struct andes_spi_slave *ds = to_andes_spi(slave);
+
+	/* Disable the SPI hardware */
+	writel(ANDES_SPI_CR_SPIRST, &ds->regs->cr);
+}
+
+static int andes_spi_read(struct spi_slave *slave, unsigned int len,
+			    u8 *rxp, unsigned long flags)
+{
+	struct andes_spi_slave *ds = to_andes_spi(slave);
+	unsigned int i, left;
+	unsigned int data;
+
+	debug("%s: slave: %x, len: %d, rxp: %x, flags: %d\n",
+		__func__, slave, len, rxp, flags);
+
+	debug("%s: data: ", __func__);
+	while (len > 0) {
+		left = min(len, 4);
+		data = readl(&ds->regs->data);
+
+		debug(" ");
+		for (i = 0; i < left; i++) {
+			debug("%02x ", data & 0xff);
+			*rxp++ = data;
+			data >>= 8;
+			len--;
+		}
+	}
+	debug("\n");
+
+	return 0;
+}
+
+static int andes_spi_write(struct spi_slave *slave, unsigned int wlen,
+			unsigned int rlen, const u8 *txp, unsigned long flags)
+{
+	struct andes_spi_slave *ds = to_andes_spi(slave);
+	unsigned int data;
+	unsigned int i, left;
+	unsigned int spit_enabled = 0;
+
+	debug("%s: slave: %x, wlen: %d, rlen: %d, txp: %x, flags: %x\n",
+		__func__, slave, wlen, rlen, txp, flags);
+
+	/* The value of wlen and rlen wrote to register must minus 1 */
+	if (rlen == 0)					/* write only */
+		writel(ANDES_SPI_DCR_MODE_WO | ANDES_SPI_DCR_WCNT(wlen-1) |
+				ANDES_SPI_DCR_RCNT(0), &ds->regs->dcr);
+	else						/* write then read */
+		writel(ANDES_SPI_DCR_MODE_WR | ANDES_SPI_DCR_WCNT(wlen-1) |
+				ANDES_SPI_DCR_RCNT(rlen-1), &ds->regs->dcr);
+
+	/* wait till SPIBSY is cleared */
+	while (readl(&ds->regs->st) & ANDES_SPI_ST_SPIBSY)
+		;
+
+	/* data write process */
+	debug("%s: txp: ", __func__);
+	while (wlen > 0) {
+		/* clear the data */
+		data = 0;
+
+		/* data are usually be read 32bits once a time */
+		left = min(wlen, 4);
+
+		for (i = 0; i < left; i++) {
+			debug("%x ", *txp);
+			data |= *txp++ << (i * 8);
+			wlen--;
+		}
+		debug("\n");
+
+		debug("data: %08x\n", data);
+		debug("streg before write: %08x\n", readl(&ds->regs->st));
+		/* wait till TXFULL is deasserted */
+		while (readl(&ds->regs->st) & ANDES_SPI_ST_TXFEL)
+			;
+		writel(data, &ds->regs->data);
+		debug("streg after write: %08x\n", readl(&ds->regs->st));
+
+
+		if (spit_enabled == 0) {
+			/* enable SPIT bit -  trigger the tx and rx progress */
+			andes_spi_spit_en(ds);
+			spit_enabled = 1;
+		}
+
+	}
+	debug("\n");
+
+	return 0;
+}
+
+/*
+ * spi_xfer:
+ *	Since andes_spi doesn't support independent command transaction,
+ *	that is, write and than read must be operated in continuous
+ *	execution, there is no need to set dcr and trigger spit again in
+ *	RX process.
+ */
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+	     const void *dout, void *din, unsigned long flags)
+{
+	unsigned int len;
+	static int op_nextime;
+	static u8 tmp_cmd[5];
+	static int tmp_wlen;
+	unsigned int i;
+
+	if (bitlen == 0)
+		/* Finish any previously submitted transfers */
+		goto out;
+
+	if (bitlen % 8) {
+		/* Errors always terminate an ongoing transfer */
+		flags |= SPI_XFER_END;
+		goto out;
+	}
+
+	len = bitlen / 8;
+
+	debug("%s: slave: %08x, bitlen: %d, dout: "
+		"%08x, din: %08x, flags: %d, len: %d\n",
+		__func__, slave, bitlen, dout, din, flags, len);
+
+	/*
+	 * Important:
+	 *	andes_spi's hardware doesn't support 2 data channel. The read
+	 *	and write cmd/data share the same register (data register).
+	 *
+	 *	If a command has write and read transaction, you cannot do write
+	 *	this time and then do read on next time.
+	 *
+	 *	A command writes first with a read response must indicating
+	 *	the read length in write operation. Hence the write action must
+	 *	be stored temporary and wait until the next read action has been
+	 *	arrived. Then we flush the write and read action out together.
+	 */
+	if (!dout) {
+		if (op_nextime == 1) {
+			/* flags should be SPI_XFER_END, value is 2 */
+			op_nextime = 0;
+			andes_spi_write(slave, tmp_wlen, len, tmp_cmd, flags);
+		}
+		return andes_spi_read(slave, len, din, flags);
+	} else if (!din) {
+		if (flags == SPI_XFER_BEGIN) {
+			/* store the write command and do operation next time */
+			op_nextime = 1;
+			memset(tmp_cmd, 0, sizeof(tmp_cmd));
+			memcpy(tmp_cmd, dout, len);
+
+			debug("%s: tmp_cmd: ", __func__);
+			for (i = 0; i < len; i++)
+				debug("%x ", *(tmp_cmd + i));
+			debug("\n");
+
+			tmp_wlen = len;
+		} else {
+			/*
+			 * flags should be (SPI_XFER_BEGIN | SPI_XFER_END),
+			 * the value is 3.
+			 */
+			if (op_nextime == 1) {
+				/* flags should be SPI_XFER_END, value is 2 */
+				op_nextime = 0;
+				/* flags 3 implies write only */
+				andes_spi_write(slave, tmp_wlen, 0, tmp_cmd, 3);
+			}
+
+			debug("flags: %x\n", flags);
+			return andes_spi_write(slave, len, 0, dout, flags);
+		}
+	}
+
+out:
+	return 0;
+}
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	return bus == 0 && cs == 0;
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+	/* do nothing */
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+	/* do nothing */
+}

drivers/spi/andes_spi.h

@@ -0,0 +1,128 @@
+/*
+ * Register definitions for the Andes SPI Controller
+ *
+ * (C) Copyright 2011 Andes Technology
+ * Macpaul Lin <macpaul@andestech.com>
+ *
+ * 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
+ */
+
+#ifndef __ANDES_SPI_H
+#define __ANDES_SPI_H
+
+struct andes_spi_regs {
+	unsigned int	apb;		/* 0x00 - APB SPI interface setting */
+	unsigned int	pio;		/* 0x04 - PIO reg */
+	unsigned int	cr;		/* 0x08 - SPI Control reg */
+	unsigned int	st;		/* 0x0c - SPI Status reg */
+	unsigned int	ie;		/* 0x10 - Interrupt Enable reg */
+	unsigned int	ist;		/* 0x14 - Interrupt Status reg */
+	unsigned int	dcr;		/* 0x18 - data control reg */
+	unsigned int	data;		/* 0x1c - data register */
+	unsigned int	ahb;		/* 0x20 - AHB SPI interface setting */
+	unsigned int	ver;		/* 0x3c - SPI version reg */
+};
+
+#define BIT(x)			(1 << (x))
+
+/* 0x00 - APB SPI interface setting register */
+#define ANDES_SPI_APB_BAUD(x)	(((x) & 0xff) < 0)
+#define ANDES_SPI_APB_CSHT(x)	(((x) & 0xf) < 16)
+#define ANDES_SPI_APB_SPNTS	BIT(20)		/* 0: normal, 1: delay */
+#define ANDES_SPI_APB_CPHA	BIT(24)		/* 0: Sampling at odd edges */
+#define ANDES_SPI_APB_CPOL	BIT(25)		/* 0: SCK low, 1: SCK high */
+#define ANDES_SPI_APB_MSSL	BIT(26)		/* 0: SPI Master, 1: slave */
+
+/* 0x04 - PIO register */
+#define ANDES_SPI_PIO_MISO	BIT(0)		/* input value of pin MISO */
+#define ANDES_SPI_PIO_MOSI	BIT(1)		/* I/O value of pin MOSI */
+#define ANDES_SPI_PIO_SCK	BIT(2)		/* I/O value of pin SCK */
+#define ANDES_SPI_PIO_CS	BIT(3)		/* I/O value of pin CS */
+#define ANDES_SPI_PIO_PIOE	BIT(4)		/* Programming IO Enable */
+
+/* 0x08 - SPI Control register */
+#define ANDES_SPI_CR_SPIRST	BIT(0)		/* SPI mode reset */
+#define ANDES_SPI_CR_RXFRST	BIT(1)		/* RxFIFO reset */
+#define ANDES_SPI_CR_TXFRST	BIT(2)		/* TxFIFO reset */
+#define ANDES_SPI_CR_RXFTH(x)	(((x) & 0x1f) << 10)	/* RxFIFO Threshold */
+#define ANDES_SPI_CR_TXFTH(x)	(((x) & 0x1f) << 18)	/* TxFIFO Threshold */
+
+/* 0x0c - SPI Status register */
+#define ANDES_SPI_ST_SPIBSY	BIT(0)		/* SPI Transfer is active */
+#define ANDES_SPI_ST_RXFEM	BIT(8)		/* RxFIFO Empty Flag */
+#define ANDES_SPI_ST_RXFEL	BIT(9)		/* RxFIFO Full Flag */
+#define ANDES_SPI_ST_RXFVE(x)	(((x) >> 10) & 0x1f)
+#define ANDES_SPI_ST_TXFEM	BIT(16)		/* TxFIFO Empty Flag */
+#define ANDES_SPI_ST_TXFEL	BIT(7)		/* TxFIFO Full Flag */
+#define ANDES_SPI_ST_TXFVE(x)	(((x) >> 18) & 0x1f)
+
+/* 0x10 - Interrupt Enable register */
+#define ANDES_SPI_IE_RXFORIE	BIT(0)		/* RxFIFO overrun intr */
+#define ANDES_SPI_IE_TXFURIE	BIT(1)		/* TxFOFO underrun intr */
+#define ANDES_SPI_IE_RXFTHIE	BIT(2)		/* RxFIFO threshold intr */
+#define ANDES_SPI_IE_TXFTHIE	BIT(3)		/* TxFIFO threshold intr */
+#define ANDES_SPI_IE_SPIEIE	BIT(4)		/* SPI transmit END intr */
+#define ANDES_SPI_IE_SPCFIE	BIT(5)		/* AHB/APB TxReq conflict */
+
+/* 0x14 - Interrupt Status Register */
+#define ANDES_SPI_IST_RXFORI	BIT(0)		/* has RxFIFO overrun */
+#define ANDES_SPI_IST_TXFURI	BIT(1)		/* has TxFOFO underrun */
+#define ANDES_SPI_IST_RXFTHI	BIT(2)		/* has RxFIFO threshold */
+#define ANDES_SPI_IST_TXFTHI	BIT(3)		/* has TxFIFO threshold */
+#define ANDES_SPI_IST_SPIEI	BIT(4)		/* has SPI transmit END */
+#define ANDES_SPI_IST_SPCFI	BIT(5)		/* has AHB/APB TxReq conflict */
+
+/* 0x18 - Data Control Register */
+#define ANDES_SPI_DCR_RCNT(x)		(((x) & 0x3ff) << 0)
+#define ANDES_SPI_DCR_DYCNT(x)		(((x) & 0x7) << 12)
+#define ANDES_SPI_DCR_WCNT(x)		(((x) & 0x3ff) << 16)
+#define ANDES_SPI_DCR_TRAMODE(x)	(((x) & 0x7) << 28)
+#define ANDES_SPI_DCR_SPIT		BIT(31)		/* SPI bus trigger */
+
+#define ANDES_SPI_DCR_MODE_WRCON	ANDES_SPI_DCR_TRAMODE(0)	/* w/r at the same time */
+#define ANDES_SPI_DCR_MODE_WO		ANDES_SPI_DCR_TRAMODE(1)	/* write only		*/
+#define ANDES_SPI_DCR_MODE_RO		ANDES_SPI_DCR_TRAMODE(2)	/* read only		*/
+#define ANDES_SPI_DCR_MODE_WR		ANDES_SPI_DCR_TRAMODE(3)	/* write, read		*/
+#define ANDES_SPI_DCR_MODE_RW		ANDES_SPI_DCR_TRAMODE(4)	/* read, write		*/
+#define ANDES_SPI_DCR_MODE_WDR		ANDES_SPI_DCR_TRAMODE(5)	/* write, dummy, read	*/
+#define ANDES_SPI_DCR_MODE_RDW		ANDES_SPI_DCR_TRAMODE(6)	/* read, dummy, write	*/
+#define ANDES_SPI_DCR_MODE_RECEIVE	ANDES_SPI_DCR_TRAMODE(7)	/* receive		*/
+
+/* 0x20 - AHB SPI interface setting register */
+#define ANDES_SPI_AHB_BAUD(x)	(((x) & 0xff) < 0)
+#define ANDES_SPI_AHB_CSHT(x)	(((x) & 0xf) < 16)
+#define ANDES_SPI_AHB_SPNTS	BIT(20)		/* 0: normal, 1: delay */
+#define ANDES_SPI_AHB_CPHA	BIT(24)		/* 0: Sampling at odd edges */
+#define ANDES_SPI_AHB_CPOL	BIT(25)		/* 0: SCK low, 1: SCK high */
+#define ANDES_SPI_AHB_MSSL	BIT(26)		/* only Master mode */
+
+/* 0x3c - Version Register - (Year V.MAJOR.MINOR) */
+#define ANDES_SPI_VER_MINOR(x)	(((x) >> 0) & 0xf)
+#define ANDES_SPI_VER_MAJOR(x)	(((x) >> 8) & 0xf)
+#define ANDES_SPI_VER_YEAR(x)	(((x) >> 16) & 0xf)
+
+struct andes_spi_slave {
+	struct spi_slave slave;
+	struct andes_spi_regs *regs;
+	unsigned int freq;
+};
+
+static inline struct andes_spi_slave *to_andes_spi(struct spi_slave *slave)
+{
+	return container_of(slave, struct andes_spi_slave, slave);
+}
+
+#endif /* __ANDES_SPI_H */