[U-Boot-Users] [PATCH v2 1/3] New i.MX31 SPI driver
Guennadi Liakhovetski
lg at denx.de
Tue Apr 15 14:14:25 CEST 2008
This is an SPI driver for i.MX and MXC based SoCs from Freescale. So far
only implemented and tested on i.MX31, can with a modified register layout
and definitions be used for i.MX27, I think, MXC CPUs have similar SPI
controllers too.
Signed-off-by: Guennadi Liakhovetski <lg at denx.de>
---
Changes since v1: fix a copy-paste error
README | 5 +
drivers/spi/Makefile | 1 +
drivers/spi/mxc_spi.c | 166 +++++++++++++++++++++++++++++++++
include/asm-arm/arch-mx31/mx31-regs.h | 7 +-
include/spi.h | 16 +++-
5 files changed, 193 insertions(+), 2 deletions(-)
create mode 100644 drivers/spi/mxc_spi.c
diff --git a/README b/README
index 7c16345..d201b92 100644
--- a/README
+++ b/README
@@ -1414,6 +1414,11 @@ The following options need to be configured:
Currently supported on some MPC8xxx processors. For an
example, see include/configs/mpc8349emds.h.
+ CONFIG_MXC_SPI
+
+ Enables the driver for the SPI controllers on i.MX and MXC
+ SoCs. Currently only i.MX31 is supported.
+
- FPGA Support: CONFIG_FPGA
Enables FPGA subsystem.
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 0b7a2df..bc8a104 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -26,6 +26,7 @@ include $(TOPDIR)/config.mk
LIB := $(obj)libspi.a
COBJS-y += mpc8xxx_spi.o
+COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
COBJS := $(COBJS-y)
SRCS := $(COBJS:.o=.c)
diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
new file mode 100644
index 0000000..b2e3ab9
--- /dev/null
+++ b/drivers/spi/mxc_spi.c
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2008, Guennadi Liakhovetski <lg at denx.de>
+ *
+ * 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 <asm/io.h>
+
+#ifdef CONFIG_MX27
+/* i.MX27 has a completely wrong register layout and register definitions in the
+ * datasheet, the correct one is in the Freescale's Linux driver */
+
+#error "i.MX27 CSPI not supported due to drastic differences in register definisions" \
+"See linux mxc_spi driver from Freescale for details."
+
+#else
+
+#define MXC_CSPIRXDATA 0x00
+#define MXC_CSPITXDATA 0x04
+#define MXC_CSPICTRL 0x08
+#define MXC_CSPIINT 0x0C
+#define MXC_CSPIDMA 0x10
+#define MXC_CSPISTAT 0x14
+#define MXC_CSPIPERIOD 0x18
+#define MXC_CSPITEST 0x1C
+#define MXC_CSPIRESET 0x00
+
+#define MXC_CSPICTRL_EN (1 << 0)
+#define MXC_CSPICTRL_MODE (1 << 1)
+#define MXC_CSPICTRL_XCH (1 << 2)
+#define MXC_CSPICTRL_SMC (1 << 3)
+#define MXC_CSPICTRL_POL (1 << 4)
+#define MXC_CSPICTRL_PHA (1 << 5)
+#define MXC_CSPICTRL_SSCTL (1 << 6)
+#define MXC_CSPICTRL_SSPOL (1 << 7)
+#define MXC_CSPICTRL_CHIPSELECT(x) (((x) & 0x3) << 24)
+#define MXC_CSPICTRL_BITCOUNT(x) (((x) & 0x1f) << 8)
+#define MXC_CSPICTRL_DATARATE(x) (((x) & 0x7) << 16)
+
+#define MXC_CSPIPERIOD_32KHZ (1 << 15)
+
+static unsigned long spi_bases[] = {
+ 0x43fa4000,
+ 0x50010000,
+ 0x53f84000,
+};
+
+static unsigned long spi_base;
+
+#endif
+
+spi_chipsel_type spi_chipsel[] = {
+ (spi_chipsel_type)0,
+ (spi_chipsel_type)1,
+ (spi_chipsel_type)2,
+ (spi_chipsel_type)3,
+};
+int spi_chipsel_cnt = sizeof(spi_chipsel) / sizeof(spi_chipsel[0]);
+
+static inline u32 reg_read(unsigned long addr)
+{
+ return *(volatile unsigned long*)addr;
+}
+
+static inline void reg_write(unsigned long addr, u32 val)
+{
+ *(volatile unsigned long*)addr = val;
+}
+
+static u32 spi_xchg_single(u32 data, int bitlen)
+{
+
+ unsigned int cfg_reg = reg_read(spi_base + MXC_CSPICTRL);
+
+ if (MXC_CSPICTRL_BITCOUNT(bitlen - 1) != (cfg_reg & MXC_CSPICTRL_BITCOUNT(31))) {
+ cfg_reg = (cfg_reg & ~MXC_CSPICTRL_BITCOUNT(31)) |
+ MXC_CSPICTRL_BITCOUNT(bitlen - 1);
+ reg_write(spi_base + MXC_CSPICTRL, cfg_reg);
+ }
+
+ reg_write(spi_base + MXC_CSPITXDATA, data);
+
+ cfg_reg |= MXC_CSPICTRL_XCH;
+
+ reg_write(spi_base + MXC_CSPICTRL, cfg_reg);
+
+ while (reg_read(spi_base + MXC_CSPICTRL) & MXC_CSPICTRL_XCH)
+ ;
+
+ return reg_read(spi_base + MXC_CSPIRXDATA);
+}
+
+int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din)
+{
+ int n_blks = (bitlen + 31) / 32;
+ u32 *out_l, *in_l;
+ int i;
+
+ if ((int)dout & 3 || (int)din & 3) {
+ printf("Error: unaligned buffers in: %p, out: %p\n", din, dout);
+ return 1;
+ }
+
+ if (!spi_base)
+ spi_select(CONFIG_MXC_SPI_IFACE, (int)chipsel, SPI_MODE_2 | SPI_CS_HIGH);
+
+ for (i = 0, in_l = (u32 *)din, out_l = (u32 *)dout;
+ i < n_blks;
+ i++, in_l++, out_l++, bitlen -= 32)
+ *in_l = spi_xchg_single(*out_l, bitlen);
+
+ return 0;
+}
+
+void spi_init(void)
+{
+}
+
+int spi_select(unsigned int bus, unsigned int dev, unsigned long mode)
+{
+ unsigned int ctrl_reg;
+
+ if (bus >= sizeof(spi_bases) / sizeof(spi_bases[0]) ||
+ dev > 3)
+ return 1;
+
+ spi_base = spi_bases[bus];
+
+ ctrl_reg = MXC_CSPICTRL_CHIPSELECT(dev) |
+ MXC_CSPICTRL_BITCOUNT(31) |
+ MXC_CSPICTRL_DATARATE(7) | /* FIXME: calculate data rate */
+ MXC_CSPICTRL_EN |
+ MXC_CSPICTRL_MODE;
+
+ if (mode & SPI_CPHA)
+ ctrl_reg |= MXC_CSPICTRL_PHA;
+ if (!(mode & SPI_CPOL))
+ ctrl_reg |= MXC_CSPICTRL_POL;
+ if (mode & SPI_CS_HIGH)
+ ctrl_reg |= MXC_CSPICTRL_SSPOL;
+
+ reg_write(spi_base + MXC_CSPIRESET, 1);
+ udelay(1);
+ reg_write(spi_base + MXC_CSPICTRL, ctrl_reg);
+ reg_write(spi_base + MXC_CSPIPERIOD,
+ MXC_CSPIPERIOD_32KHZ);
+ reg_write(spi_base + MXC_CSPIINT, 0);
+
+ return 0;
+}
diff --git a/include/asm-arm/arch-mx31/mx31-regs.h b/include/asm-arm/arch-mx31/mx31-regs.h
index 380b401..d04072e 100644
--- a/include/asm-arm/arch-mx31/mx31-regs.h
+++ b/include/asm-arm/arch-mx31/mx31-regs.h
@@ -37,6 +37,9 @@
#define CCM_UPCTL (CCM_BASE + 0x10)
#define CCM_SPCTL (CCM_BASE + 0x18)
#define CCM_COSR (CCM_BASE + 0x1C)
+#define CCM_CGR0 (CCM_BASE + 0x20)
+#define CCM_CGR1 (CCM_BASE + 0x24)
+#define CCM_CGR2 (CCM_BASE + 0x28)
#define CCMR_MDS (1 << 7)
#define CCMR_SBYCS (1 << 4)
@@ -118,7 +121,9 @@
#define MUX_CTL_RXD1 0x82
#define MUX_CTL_TXD1 0x83
#define MUX_CTL_CSPI2_MISO 0x84
-/* 0x85 .. 0x8a */
+#define MUX_CTL_CSPI2_SS0 0x85
+#define MUX_CTL_CSPI2_SS1 0x86
+#define MUX_CTL_CSPI2_SS2 0x87
#define MUX_CTL_CSPI2_MOSI 0x8b
/* The modes a specific pin can be in
diff --git a/include/spi.h b/include/spi.h
index 03dc5bc..3a55a68 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -24,6 +24,18 @@
#ifndef _SPI_H_
#define _SPI_H_
+/* SPI mode flags */
+#define SPI_CPHA 0x01 /* clock phase */
+#define SPI_CPOL 0x02 /* clock polarity */
+#define SPI_MODE_0 (0|0) /* (original MicroWire) */
+#define SPI_MODE_1 (0|SPI_CPHA)
+#define SPI_MODE_2 (SPI_CPOL|0)
+#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
+#define SPI_CS_HIGH 0x04 /* chipselect active high? */
+#define SPI_LSB_FIRST 0x08 /* per-word bits-on-wire */
+#define SPI_3WIRE 0x10 /* SI/SO signals shared */
+#define SPI_LOOP 0x20 /* loopback mode */
+
/*
* The function call pointer type used to drive the chip select.
*/
@@ -68,6 +80,8 @@ void spi_init(void);
*
* Returns: 0 on success, not 0 on failure
*/
-int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din);
+int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din);
+
+int spi_select(unsigned int bus, unsigned int dev, unsigned long mode);
#endif /* _SPI_H_ */
--
1.5.4
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