spi: add support SuperH SPI module
authorYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Mon, 31 Jan 2011 07:50:43 +0000 (16:50 +0900)
committerNobuhiro Iwamatsu <iwamatsu@nigauri.org>
Wed, 2 Feb 2011 07:38:41 +0000 (16:38 +0900)
SH7757 has SPI module. This patch supports it.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
README
drivers/spi/Makefile
drivers/spi/sh_spi.c [new file with mode: 0644]
drivers/spi/sh_spi.h [new file with mode: 0644]

diff --git a/README b/README
index e005bc5..37eda11 100644 (file)
--- a/README
+++ b/README
@@ -1660,6 +1660,11 @@ The following options need to be configured:
                SPI EEPROM, also an instance works with Crystal A/D and
                D/As on the SACSng board)
 
+               CONFIG_SH_SPI
+
+               Enables the driver for SPI controller on SuperH. Currently
+               only SH7757 is supported.
+
                CONFIG_SPI_X
 
                Enables extended (16-bit) SPI EEPROM addressing.
index e34a124..d582fbb 100644 (file)
@@ -37,6 +37,7 @@ COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
 COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
 COBJS-$(CONFIG_OMAP3_SPI) += omap3_spi.o
 COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
+COBJS-$(CONFIG_SH_SPI) += sh_spi.o
 
 COBJS  := $(COBJS-y)
 SRCS   := $(COBJS:.o=.c)
diff --git a/drivers/spi/sh_spi.c b/drivers/spi/sh_spi.c
new file mode 100644 (file)
index 0000000..ba43bec
--- /dev/null
@@ -0,0 +1,261 @@
+/*
+ * SH SPI driver
+ *
+ * Copyright (C) 2011 Renesas Solutions Corp.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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 St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+#include <asm/io.h>
+#include "sh_spi.h"
+
+static void sh_spi_write(unsigned long data, unsigned long *reg)
+{
+       writel(data, reg);
+}
+
+static unsigned long sh_spi_read(unsigned long *reg)
+{
+       return readl(reg);
+}
+
+static void sh_spi_set_bit(unsigned long val, unsigned long *reg)
+{
+       unsigned long tmp;
+
+       tmp = sh_spi_read(reg);
+       tmp |= val;
+       sh_spi_write(tmp, reg);
+}
+
+static void sh_spi_clear_bit(unsigned long val, unsigned long *reg)
+{
+       unsigned long tmp;
+
+       tmp = sh_spi_read(reg);
+       tmp &= ~val;
+       sh_spi_write(tmp, reg);
+}
+
+static void clear_fifo(struct sh_spi *ss)
+{
+       sh_spi_set_bit(SH_SPI_RSTF, &ss->regs->cr2);
+       sh_spi_clear_bit(SH_SPI_RSTF, &ss->regs->cr2);
+}
+
+static int recvbuf_wait(struct sh_spi *ss)
+{
+       while (sh_spi_read(&ss->regs->cr1) & SH_SPI_RBE) {
+               if (ctrlc())
+                       return 1;
+               udelay(10);
+       }
+       return 0;
+}
+
+static int write_fifo_empty_wait(struct sh_spi *ss)
+{
+       while (!(sh_spi_read(&ss->regs->cr1) & SH_SPI_TBE)) {
+               if (ctrlc())
+                       return 1;
+               udelay(10);
+       }
+       return 0;
+}
+
+void spi_init(void)
+{
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+               unsigned int max_hz, unsigned int mode)
+{
+       struct sh_spi *ss;
+
+       if (!spi_cs_is_valid(bus, cs))
+               return NULL;
+
+       ss = malloc(sizeof(struct spi_slave));
+       if (!ss)
+               return NULL;
+
+       ss->slave.bus = bus;
+       ss->slave.cs = cs;
+       ss->regs = (struct sh_spi_regs *)CONFIG_SH_SPI_BASE;
+
+       /* SPI sycle stop */
+       sh_spi_write(0xfe, &ss->regs->cr1);
+       /* CR1 init */
+       sh_spi_write(0x00, &ss->regs->cr1);
+       /* CR3 init */
+       sh_spi_write(0x00, &ss->regs->cr3);
+
+       clear_fifo(ss);
+
+       /* 1/8 clock */
+       sh_spi_write(sh_spi_read(&ss->regs->cr2) | 0x07, &ss->regs->cr2);
+       udelay(10);
+
+       return &ss->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+       struct sh_spi *spi = to_sh_spi(slave);
+
+       free(spi);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+       return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+       struct sh_spi *ss = to_sh_spi(slave);
+
+       sh_spi_write(sh_spi_read(&ss->regs->cr1) &
+               ~(SH_SPI_SSA | SH_SPI_SSDB | SH_SPI_SSD), &ss->regs->cr1);
+}
+
+static int sh_spi_send(struct sh_spi *ss, const unsigned char *tx_data,
+                       unsigned int len, unsigned long flags)
+{
+       int i, cur_len, ret = 0;
+       int remain = (int)len;
+       unsigned long tmp;
+
+       if (len >= SH_SPI_FIFO_SIZE)
+               sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1);
+
+       while (remain > 0) {
+               cur_len = (remain < SH_SPI_FIFO_SIZE) ?
+                               remain : SH_SPI_FIFO_SIZE;
+               for (i = 0; i < cur_len &&
+                       !(sh_spi_read(&ss->regs->cr4) & SH_SPI_WPABRT) &&
+                       !(sh_spi_read(&ss->regs->cr1) & SH_SPI_TBF);
+                               i++)
+                       sh_spi_write(tx_data[i], &ss->regs->tbr_rbr);
+
+               cur_len = i;
+
+               if (sh_spi_read(&ss->regs->cr4) & SH_SPI_WPABRT) {
+                       /* Abort the transaction */
+                       flags |= SPI_XFER_END;
+                       sh_spi_set_bit(SH_SPI_WPABRT, &ss->regs->cr4);
+                       ret = 1;
+                       break;
+               }
+
+               remain -= cur_len;
+               tx_data += cur_len;
+
+               if (remain > 0)
+                       write_fifo_empty_wait(ss);
+       }
+
+       if (flags & SPI_XFER_END) {
+               tmp = sh_spi_read(&ss->regs->cr1);
+               tmp = tmp & ~(SH_SPI_SSD | SH_SPI_SSDB);
+               sh_spi_write(tmp, &ss->regs->cr1);
+               sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1);
+               udelay(100);
+               write_fifo_empty_wait(ss);
+       }
+
+       return ret;
+}
+
+static int sh_spi_receive(struct sh_spi *ss, unsigned char *rx_data,
+                         unsigned int len, unsigned long flags)
+{
+       int i;
+       unsigned long tmp;
+
+       if (len > SH_SPI_MAX_BYTE)
+               sh_spi_write(SH_SPI_MAX_BYTE, &ss->regs->cr3);
+       else
+               sh_spi_write(len, &ss->regs->cr3);
+
+       tmp = sh_spi_read(&ss->regs->cr1);
+       tmp = tmp & ~(SH_SPI_SSD | SH_SPI_SSDB);
+       sh_spi_write(tmp, &ss->regs->cr1);
+       sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1);
+
+       for (i = 0; i < len; i++) {
+               if (recvbuf_wait(ss))
+                       return 0;
+
+               rx_data[i] = (unsigned char)sh_spi_read(&ss->regs->tbr_rbr);
+       }
+       sh_spi_write(0, &ss->regs->cr3);
+
+       return 0;
+}
+
+int  spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+               void *din, unsigned long flags)
+{
+       struct sh_spi *ss = to_sh_spi(slave);
+       const unsigned char *tx_data = dout;
+       unsigned char *rx_data = din;
+       unsigned int len = bitlen / 8;
+       int ret = 0;
+
+       if (flags & SPI_XFER_BEGIN)
+               sh_spi_write(sh_spi_read(&ss->regs->cr1) & ~SH_SPI_SSA,
+                               &ss->regs->cr1);
+
+       if (tx_data)
+               ret = sh_spi_send(ss, tx_data, len, flags);
+
+       if (ret == 0 && rx_data)
+               ret = sh_spi_receive(ss, rx_data, len, flags);
+
+       if (flags & SPI_XFER_END) {
+               sh_spi_set_bit(SH_SPI_SSD, &ss->regs->cr1);
+               udelay(100);
+
+               sh_spi_clear_bit(SH_SPI_SSA | SH_SPI_SSDB | SH_SPI_SSD,
+                                &ss->regs->cr1);
+               clear_fifo(ss);
+       }
+
+       return ret;
+}
+
+int  spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+       /* This driver supports "bus = 0" and "cs = 0" only. */
+       if (!bus && !cs)
+               return 1;
+       else
+               return 0;
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+
+}
+
diff --git a/drivers/spi/sh_spi.h b/drivers/spi/sh_spi.h
new file mode 100644 (file)
index 0000000..b1cf98c
--- /dev/null
@@ -0,0 +1,79 @@
+/*
+ * SH SPI driver
+ *
+ * Copyright (C) 2011 Renesas Solutions Corp.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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 St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifndef __SH_SPI_H__
+#define __SH_SPI_H__
+
+#include <spi.h>
+
+struct sh_spi_regs {
+       unsigned long tbr_rbr;
+       unsigned long resv1;
+       unsigned long cr1;
+       unsigned long resv2;
+       unsigned long cr2;
+       unsigned long resv3;
+       unsigned long cr3;
+       unsigned long resv4;
+       unsigned long cr4;
+};
+
+/* CR1 */
+#define SH_SPI_TBE     0x80
+#define SH_SPI_TBF     0x40
+#define SH_SPI_RBE     0x20
+#define SH_SPI_RBF     0x10
+#define SH_SPI_PFONRD  0x08
+#define SH_SPI_SSDB    0x04
+#define SH_SPI_SSD     0x02
+#define SH_SPI_SSA     0x01
+
+/* CR2 */
+#define SH_SPI_RSTF    0x80
+#define SH_SPI_LOOPBK  0x40
+#define SH_SPI_CPOL    0x20
+#define SH_SPI_CPHA    0x10
+#define SH_SPI_L1M0    0x08
+
+/* CR3 */
+#define SH_SPI_MAX_BYTE        0xFF
+
+/* CR4 */
+#define SH_SPI_TBEI    0x80
+#define SH_SPI_TBFI    0x40
+#define SH_SPI_RBEI    0x20
+#define SH_SPI_RBFI    0x10
+#define SH_SPI_WPABRT  0x04
+#define SH_SPI_SSS     0x01
+
+#define SH_SPI_FIFO_SIZE       32
+
+struct sh_spi {
+       struct spi_slave        slave;
+       struct sh_spi_regs      *regs;
+};
+
+static inline struct sh_spi *to_sh_spi(struct spi_slave *slave)
+{
+       return container_of(slave, struct sh_spi, slave);
+}
+
+#endif
+