[U-Boot] [PATCH v4 05/10] SPI: Add Dove SPI driver

Sascha Silbe t-uboot at infra-silbe.de
Sun May 26 20:36:58 CEST 2013


From: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>

This adds an SPI driver for Marvell Dove SoCs. This driver is taken
from kirkwood_spi but removes mpp configuration as dove has dedicated
spi pins.

As a future clean-up step, the code for orion5x, kirkwood and dove
could be merged, with MPP configuration being be handled as part of
cpu/board-specific setup.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
Signed-off-by: Sascha Silbe <t-uboot at infra-silbe.de>
---
 v3->v4: renamed to dove, adjusted description, removed unused
         variable, made checkpatch clean

 drivers/spi/Makefile   |   1 +
 drivers/spi/dove_spi.c | 212 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 213 insertions(+)
 create mode 100644 drivers/spi/dove_spi.c

diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index d08609e..62ad970 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -38,6 +38,7 @@ COBJS-$(CONFIG_BFIN_SPI6XX) += bfin_spi6xx.o
 COBJS-$(CONFIG_CF_SPI) += cf_spi.o
 COBJS-$(CONFIG_CF_QSPI) += cf_qspi.o
 COBJS-$(CONFIG_DAVINCI_SPI) += davinci_spi.o
+COBJS-$(CONFIG_DOVE_SPI) += dove_spi.o
 COBJS-$(CONFIG_EXYNOS_SPI) += exynos_spi.o
 COBJS-$(CONFIG_ICH_SPI) +=  ich.o
 COBJS-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
diff --git a/drivers/spi/dove_spi.c b/drivers/spi/dove_spi.c
new file mode 100644
index 0000000..c61ba89
--- /dev/null
+++ b/drivers/spi/dove_spi.c
@@ -0,0 +1,212 @@
+/*
+ * Marvell Dove SoCs common spi driver
+ *
+ * Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
+ * based on kirkwood_spi.c written by
+ *  Prafulla Wadaskar <prafulla at marvell.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., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+#include <asm/io.h>
+#include <asm/arch/config.h>
+
+/* SPI Registers on dove SOC */
+struct dovespi_registers {
+	u32 ctrl;	/* 0x00 */
+	u32 cfg;	/* 0x04 */
+	u32 dout;	/* 0x08 */
+	u32 din;	/* 0x0c */
+	u32 irq_cause;	/* 0x10 */
+	u32 irq_mask;	/* 0x14 */
+};
+
+#define DOVESPI_CLKPRESCL_MASK	0x1f
+#define DOVESPI_CLKPRESCL_MIN	0x12
+#define DOVESPI_CSN_ACT	1 /* Activates serial memory interface */
+#define DOVESPI_SMEMRDY	(1 << 1) /* SerMem Data xfer ready */
+#define DOVESPI_IRQUNMASK	1 /* unmask SPI interrupt */
+#define DOVESPI_IRQMASK	0 /* mask SPI interrupt */
+#define DOVESPI_SMEMRDIRQ	1 /* SerMem data xfer ready irq */
+#define DOVESPI_XFERLEN_1BYTE	0
+#define DOVESPI_XFERLEN_2BYTE	(1 << 5)
+#define DOVESPI_XFERLEN_MASK	(1 << 5)
+#define DOVESPI_ADRLEN_1BYTE	0
+#define DOVESPI_ADRLEN_2BYTE	(1 << 8)
+#define DOVESPI_ADRLEN_3BYTE	(2 << 8)
+#define DOVESPI_ADRLEN_4BYTE	(3 << 8)
+#define DOVESPI_ADRLEN_MASK	(3 << 8)
+#define DOVESPI_TIMEOUT	10000
+
+static struct dovespi_registers *spireg =
+	(struct dovespi_registers *)DOVE_SPI_BASE;
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+				unsigned int max_hz, unsigned int mode)
+{
+	struct spi_slave *slave;
+	u32 data;
+
+	if (!spi_cs_is_valid(bus, cs))
+		return NULL;
+
+	slave = malloc(sizeof(struct spi_slave));
+	if (!slave)
+		return NULL;
+
+	slave->bus = bus;
+	slave->cs = cs;
+
+	writel(~DOVESPI_CSN_ACT | DOVESPI_SMEMRDY, &spireg->ctrl);
+
+	/* calculate spi clock prescaller using max_hz */
+	data = ((CONFIG_SYS_TCLK / 2) / max_hz) + 0x10;
+	data = data < DOVESPI_CLKPRESCL_MIN ? DOVESPI_CLKPRESCL_MIN : data;
+	data = data > DOVESPI_CLKPRESCL_MASK ? DOVESPI_CLKPRESCL_MASK : data;
+
+	/* program spi clock prescaller using max_hz */
+	writel(DOVESPI_ADRLEN_3BYTE | data, &spireg->cfg);
+	debug("data = 0x%08x\n", data);
+
+	writel(DOVESPI_SMEMRDIRQ, &spireg->irq_cause);
+	writel(DOVESPI_IRQMASK, &spireg->irq_mask);
+
+	return slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	free(slave);
+}
+
+__attribute__((weak)) int board_spi_claim_bus(struct spi_slave *slave)
+{
+	return 0;
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+	return board_spi_claim_bus(slave);
+}
+
+__attribute__((weak)) void board_spi_release_bus(struct spi_slave *slave)
+{
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	board_spi_release_bus(slave);
+}
+
+#ifndef CONFIG_SPI_CS_IS_VALID
+/*
+ * you can define this function board specific
+ * define above CONFIG in board specific config file and
+ * provide the function in board specific src file
+ */
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	return (bus == 0 && (cs == 0 || cs == 1));
+}
+#endif
+
+void spi_init(void)
+{
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+	writel(readl(&spireg->ctrl) | DOVESPI_IRQUNMASK, &spireg->ctrl);
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+	writel(readl(&spireg->ctrl) & DOVESPI_IRQMASK, &spireg->ctrl);
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+	     void *din, unsigned long flags)
+{
+	unsigned int tmpdout, tmpdin;
+	int tm, isread = 0;
+
+	debug("spi_xfer: slave %u:%u dout %p din %p bitlen %u\n",
+	      slave->bus, slave->cs, dout, din, bitlen);
+
+	if (flags & SPI_XFER_BEGIN)
+		spi_cs_activate(slave);
+
+	/*
+	 * handle data in 8-bit chunks
+	 * TBD: 2byte xfer mode to be enabled
+	 */
+	writel(((readl(&spireg->cfg) & ~DOVESPI_XFERLEN_MASK) |
+		DOVESPI_XFERLEN_1BYTE), &spireg->cfg);
+
+	while (bitlen > 4) {
+		debug("loopstart bitlen %d\n", bitlen);
+		tmpdout = 0;
+
+		/* Shift data so it's msb-justified */
+		if (dout)
+			tmpdout = *(u32 *)dout & 0x0ff;
+
+		writel(~DOVESPI_SMEMRDIRQ, &spireg->irq_cause);
+		writel(tmpdout, &spireg->dout);	/* Write the data out */
+		debug("*** spi_xfer: ... %08x written, bitlen %d\n",
+		      tmpdout, bitlen);
+
+		/*
+		 * Wait for SPI transmit to get out
+		 * or time out (1 second = 1000 ms)
+		 * The NE event must be read and cleared first
+		 */
+		for (tm = 0, isread = 0; tm < DOVESPI_TIMEOUT; ++tm) {
+			if (readl(&spireg->irq_cause) & DOVESPI_SMEMRDIRQ) {
+				isread = 1;
+				tmpdin = readl(&spireg->din);
+				debug
+					("spi_xfer: din %p..%08x read\n",
+					din, tmpdin);
+
+				if (din) {
+					*((u8 *)din) = (u8)tmpdin;
+					din += 1;
+				}
+				if (dout)
+					dout += 1;
+				bitlen -= 8;
+			}
+			if (isread)
+				break;
+		}
+		if (tm >= DOVESPI_TIMEOUT)
+			printf("*** spi_xfer: Time out during SPI transfer\n");
+
+		debug("loopend bitlen %d\n", bitlen);
+	}
+
+	if (flags & SPI_XFER_END)
+		spi_cs_deactivate(slave);
+
+	return 0;
+}
-- 
1.8.2.1



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