[U-Boot] [PATCH v6] TI DaVinci: Driver for the davinci SPI controller
Sudhakar Rajashekhara
sudhakar.raj at ti.com
Mon Jan 11 10:29:58 CET 2010
From: Sekhar Nori <nsekhar at ti.com>
This adds a driver for the SPI controller found on davinci
based SoCs from Texas Instruments.
Signed-off-by: Sekhar Nori <nsekhar at ti.com>
Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj at ti.com>
---
Modification from the previous version:
1. One unused member (mr) has been removed from davinci_spi_slave
structure.
drivers/spi/Makefile | 1 +
drivers/spi/davinci_spi.c | 223 +++++++++++++++++++++++++++++++++++++++++++++
drivers/spi/davinci_spi.h | 101 ++++++++++++++++++++
3 files changed, 325 insertions(+), 0 deletions(-)
create mode 100644 drivers/spi/davinci_spi.c
create mode 100644 drivers/spi/davinci_spi.h
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 824d8e7..f112ed0 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -29,6 +29,7 @@ COBJS-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o
COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
COBJS-$(CONFIG_BFIN_SPI) += bfin_spi.o
COBJS-$(CONFIG_CF_SPI) += cf_spi.o
+COBJS-$(CONFIG_DAVINCI_SPI) += davinci_spi.o
COBJS-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
COBJS-$(CONFIG_MPC52XX_SPI) += mpc52xx_spi.o
COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
new file mode 100644
index 0000000..ebc7f80
--- /dev/null
+++ b/drivers/spi/davinci_spi.c
@@ -0,0 +1,223 @@
+/*
+ * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * Driver for SPI controller on DaVinci. Based on atmel_spi.c
+ * by Atmel Corporation
+ *
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * 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 <spi.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+#include "davinci_spi.h"
+
+void spi_init()
+{
+ /* do nothing */
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct davinci_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 davinci_spi_regs *)CONFIG_SYS_SPI_BASE;
+ ds->freq = max_hz;
+
+ return &ds->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+
+ free(ds);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+ unsigned int scalar, data1_reg_val = 0;
+
+ /* Enable the SPI hardware */
+ writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
+ udelay(1000);
+ writel(SPIGCR0_SPIENA_MASK, &ds->regs->gcr0);
+
+ /* Set master mode, powered up and not activated */
+ writel(SPIGCR1_MASTER_MASK | SPIGCR1_CLKMOD_MASK, &ds->regs->gcr1);
+
+ /* CS, CLK, SIMO and SOMI are functional pins */
+ writel((SPIPC0_EN0FUN_MASK | SPIPC0_CLKFUN_MASK |
+ SPIPC0_DOFUN_MASK | SPIPC0_DIFUN_MASK), &ds->regs->pc0);
+
+ /* setup format */
+ scalar = ((CONFIG_SYS_SPI_CLK / ds->freq) - 1) & 0xFF;
+
+ /*
+ * Use following format:
+ * character length = 8,
+ * clock signal delayed by half clk cycle,
+ * clock low in idle state - Mode 0,
+ * MSB shifted out first
+ */
+ writel(8 | (scalar << SPIFMT_PRESCALE_SHIFT) |
+ (1 << SPIFMT_PHASE_SHIFT), &ds->regs->fmt0);
+
+ /* hold cs active at end of transfer until explicitly de-asserted */
+ data1_reg_val = (1 << SPIDAT1_CSHOLD_SHIFT) |
+ (slave->cs << SPIDAT1_CSNR_SHIFT);
+ writel(data1_reg_val, &ds->regs->dat1);
+
+ /*
+ * Including a minor delay. No science here. Should be good even with
+ * no delay
+ */
+ writel((50 << SPI_C2TDELAY_SHIFT) |
+ (50 << SPI_T2CDELAY_SHIFT), &ds->regs->delay);
+
+ /* default chip select register */
+ writel(SPIDEF_CSDEF0_MASK, &ds->regs->def);
+
+ /* no interrupts */
+ writel(0, &ds->regs->int0);
+ writel(0, &ds->regs->lvl);
+
+ /* enable SPI */
+ writel((readl(&ds->regs->gcr1) | SPIGCR1_SPIENA_MASK), &ds->regs->gcr1);
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+
+ /* Disable the SPI hardware */
+ writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+ unsigned int len, data1_reg_val = readl(&ds->regs->dat1);
+ int ret, i;
+ const u8 *txp = dout; /* dout can be NULL for read operation */
+ u8 *rxp = din; /* din can be NULL for write operation */
+
+ ret = 0;
+
+ if (bitlen == 0)
+ /* Finish any previously submitted transfers */
+ goto out;
+
+ /*
+ * It's not clear how non-8-bit-aligned transfers are supposed to be
+ * represented as a stream of bytes...this is a limitation of
+ * the current SPI interface - here we terminate on receiving such a
+ * transfer request.
+ */
+ if (bitlen % 8) {
+ /* Errors always terminate an ongoing transfer */
+ flags |= SPI_XFER_END;
+ goto out;
+ }
+
+ len = bitlen / 8;
+
+ /* do an empty read to clear the current contents */
+ readl(&ds->regs->buf);
+
+ /* keep writing and reading 1 byte until done */
+ for (i = 0; i < len; i++) {
+ /* wait till TXFULL is asserted */
+ while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK);
+
+ /* write the data */
+ data1_reg_val &= ~0xFFFF;
+ if (txp) {
+ data1_reg_val |= *txp;
+ txp++;
+ }
+
+ /*
+ * Write to DAT1 is required to keep the serial transfer going.
+ * We just terminate when we reach the end.
+ */
+ if ((i == (len - 1)) && (flags & SPI_XFER_END)) {
+ /* clear CS hold */
+ writel(data1_reg_val &
+ ~(1 << SPIDAT1_CSHOLD_SHIFT), &ds->regs->dat1);
+ } else {
+ /* enable CS hold */
+ data1_reg_val |= ((1 << SPIDAT1_CSHOLD_SHIFT) |
+ (slave->cs << SPIDAT1_CSNR_SHIFT));
+ writel(data1_reg_val, &ds->regs->dat1);
+ }
+
+ /* read the data - wait for data availability */
+ while (readl(&ds->regs->buf) & SPIBUF_RXEMPTY_MASK);
+
+ if (rxp) {
+ *rxp = readl(&ds->regs->buf) & 0xFF;
+ rxp++;
+ } else {
+ /* simply drop the read character */
+ readl(&ds->regs->buf);
+ }
+ }
+ return 0;
+
+out:
+ if (flags & SPI_XFER_END) {
+ writel(data1_reg_val &
+ ~(1 << SPIDAT1_CSHOLD_SHIFT), &ds->regs->dat1);
+ }
+ 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 */
+}
+
diff --git a/drivers/spi/davinci_spi.h b/drivers/spi/davinci_spi.h
new file mode 100644
index 0000000..8d36a42
--- /dev/null
+++ b/drivers/spi/davinci_spi.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * Register definitions for the DaVinci SPI Controller
+ *
+ * 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 _DAVINCI_SPI_H_
+#define _DAVINCI_SPI_H_
+
+struct davinci_spi_regs {
+ dv_reg gcr0; /* 0x00 */
+ dv_reg gcr1; /* 0x04 */
+ dv_reg int0; /* 0x08 */
+ dv_reg lvl; /* 0x0c */
+ dv_reg flg; /* 0x10 */
+ dv_reg pc0; /* 0x14 */
+ dv_reg pc1; /* 0x18 */
+ dv_reg pc2; /* 0x1c */
+ dv_reg pc3; /* 0x20 */
+ dv_reg pc4; /* 0x24 */
+ dv_reg pc5; /* 0x28 */
+ dv_reg rsvd[3];
+ dv_reg dat0; /* 0x38 */
+ dv_reg dat1; /* 0x3c */
+ dv_reg buf; /* 0x40 */
+ dv_reg emu; /* 0x44 */
+ dv_reg delay; /* 0x48 */
+ dv_reg def; /* 0x4c */
+ dv_reg fmt0; /* 0x50 */
+ dv_reg fmt1; /* 0x54 */
+ dv_reg fmt2; /* 0x58 */
+ dv_reg fmt3; /* 0x5c */
+ dv_reg intvec0; /* 0x60 */
+ dv_reg intvec1; /* 0x64 */
+};
+
+#define BIT(x) (1 << (x))
+
+/* SPIGCR0 */
+#define SPIGCR0_SPIENA_MASK 0x1
+#define SPIGCR0_SPIRST_MASK 0x0
+
+/* SPIGCR0 */
+#define SPIGCR1_CLKMOD_MASK BIT(1)
+#define SPIGCR1_MASTER_MASK BIT(0)
+#define SPIGCR1_SPIENA_MASK BIT(24)
+
+/* SPIPC0 */
+#define SPIPC0_DIFUN_MASK BIT(11) /* SIMO */
+#define SPIPC0_DOFUN_MASK BIT(10) /* SOMI */
+#define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */
+#define SPIPC0_EN0FUN_MASK BIT(0)
+
+/* SPIFMT0 */
+#define SPIFMT_SHIFTDIR_SHIFT 20
+#define SPIFMT_POLARITY_SHIFT 17
+#define SPIFMT_PHASE_SHIFT 16
+#define SPIFMT_PRESCALE_SHIFT 8
+
+/* SPIDAT1 */
+#define SPIDAT1_CSHOLD_SHIFT 28
+#define SPIDAT1_CSNR_SHIFT 16
+
+/* SPIDELAY */
+#define SPI_C2TDELAY_SHIFT 24
+#define SPI_T2CDELAY_SHIFT 16
+
+/* SPIBUF */
+#define SPIBUF_RXEMPTY_MASK BIT(31)
+#define SPIBUF_TXFULL_MASK BIT(29)
+
+/* SPIDEF */
+#define SPIDEF_CSDEF0_MASK BIT(0)
+
+struct davinci_spi_slave {
+ struct spi_slave slave;
+ struct davinci_spi_regs *regs;
+ unsigned int freq;
+};
+
+static inline struct davinci_spi_slave *to_davinci_spi(struct spi_slave *slave)
+{
+ return container_of(slave, struct davinci_spi_slave, slave);
+}
+
+#endif /* _DAVINCI_SPI_H_ */
--
1.5.6
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