Add driver for the ST M95xxx SPI EEPROM

This chip is used in a number of boards manufactured by Calao-Systems which should be supported soon. This driver provides the necessary spi_read and spi_write functions necessary to communicate with the chip. Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>

Add driver for the ST M95xxx SPI EEPROM
This chip is used in a number of boards manufactured by Calao-Systems which should be supported soon. This driver provides the necessary spi_read and spi_write functions necessary to communicate with the chip. Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Albin Tonnerre · Wolfgang Denk
1 parent 30951960ba
Showing 2 changed files with 118 additions and 0 deletions Side-by-side Diff
drivers/mtd/spi/Makefile
drivers/mtd/spi/eeprom_m95xxx.c
@@ -31,6 +31,7 @@
 COBJS-$(CONFIG_SPI_FLASH_SPANSION)	+= spansion.o
 COBJS-$(CONFIG_SPI_FLASH_SST)	+= sst.o
 COBJS-$(CONFIG_SPI_FLASH_STMICRO)	+= stmicro.o
+COBJS-$(CONFIG_SPI_M95XXX) += eeprom_m95xxx.o
  
 COBJS	:= $(COBJS-y)
 SRCS	:= $(COBJS:.o=.c)
+/*
+ * Copyright (C) 2009
+ * Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.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 <spi.h>
+
+#define SPI_EEPROM_WREN		0x06
+#define SPI_EEPROM_RDSR		0x05
+#define SPI_EEPROM_READ		0x03
+#define SPI_EEPROM_WRITE	0x02
+
+#ifndef CONFIG_DEFAULT_SPI_BUS
+#define CONFIG_DEFAULT_SPI_BUS 0
+#endif
+
+#ifndef CONFIG_DEFAULT_SPI_MODE
+#define CONFIG_DEFAULT_SPI_MODE SPI_MODE_0
+#endif
+
+ssize_t spi_read (uchar *addr, int alen, uchar *buffer, int len)
+{
+	struct spi_slave *slave;
+	u8 cmd = SPI_EEPROM_READ;
+
+	slave = spi_setup_slave(CONFIG_DEFAULT_SPI_BUS, 1, 1000000,
+			CONFIG_DEFAULT_SPI_MODE);
+	spi_claim_bus(slave);
+
+	/* command */
+	if(spi_xfer(slave, 8, &cmd, NULL, SPI_XFER_BEGIN))
+		return -1;
+
+	/*
+	 * if alen == 3, addr[0] is the block number, we never use it here. All we
+	 * need are the lower 16 bits
+	 */
+	if (alen == 3)
+		addr++;
+
+	/* address, and data */
+	if(spi_xfer(slave, 16, addr, NULL, 0))
+		return -1;
+	if(spi_xfer(slave, 8 * len, NULL, buffer, SPI_XFER_END))
+		return -1;
+
+	spi_release_bus(slave);
+	spi_free_slave(slave);
+	return len;
+}
+
+ssize_t spi_write (uchar *addr, int alen, uchar *buffer, int len)
+{
+	struct spi_slave *slave;
+	int i;
+	char buf[3];
+
+	slave = spi_setup_slave(CONFIG_DEFAULT_SPI_BUS, 1, 1000000,
+			CONFIG_DEFAULT_SPI_MODE);
+	spi_claim_bus(slave);
+
+	buf[0] = SPI_EEPROM_WREN;
+	if(spi_xfer(slave, 8, buf, NULL, SPI_XFER_BEGIN | SPI_XFER_END))
+		return -1;
+
+	buf[0] = SPI_EEPROM_WRITE;
+
+	/* As for reading, drop addr[0] if alen is 3 */
+	if (alen == 3) {
+		alen--;
+		addr++;
+	}
+
+	memcpy(buf + 1, addr, alen);
+	/* command + addr, then data */
+	if(spi_xfer(slave, 24, buf, NULL, SPI_XFER_BEGIN))
+		return -1;
+	if(spi_xfer(slave, len * 8, buffer, NULL, SPI_XFER_END))
+		return -1;
+
+	reset_timer_masked();
+	do {
+		buf[0] = SPI_EEPROM_RDSR;
+		buf[1] = 0;
+		spi_xfer(slave, 16, buf, buf, SPI_XFER_BEGIN | SPI_XFER_END);
+
+		if (!(buf[1] & 1))
+			break;
+
+	} while (get_timer_masked() < CONFIG_SYS_SPI_WRITE_TOUT);
+
+	if (buf[1] & 1)
+		printf ("*** spi_write: Time out while writing!\n");
+
+	spi_release_bus(slave);
+	spi_free_slave(slave);
+	return len;
+}
...	...	@@ -31,6 +31,7 @@
31	31	COBJS-$(CONFIG_SPI_FLASH_SPANSION) += spansion.o
32	32	COBJS-$(CONFIG_SPI_FLASH_SST) += sst.o
33	33	COBJS-$(CONFIG_SPI_FLASH_STMICRO) += stmicro.o
	34	+COBJS-$(CONFIG_SPI_M95XXX) += eeprom_m95xxx.o
34	35
35	36	COBJS := $(COBJS-y)
36	37	SRCS := $(COBJS:.o=.c)
	1	+/*
	2	+ * Copyright (C) 2009
	3	+ * Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.com>
	4	+ *
	5	+ * See file CREDITS for list of people who contributed to this
	6	+ * project.
	7	+ *
	8	+ * This program is free software; you can redistribute it and/or
	9	+ * modify it under the terms of the GNU General Public License as
	10	+ * published by the Free Software Foundation; either version 2 of
	11	+ * the License, or (at your option) any later version.
	12	+ *
	13	+ * This program is distributed in the hope that it will be useful,
	14	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	+ * GNU General Public License for more details.
	17	+ *
	18	+ * You should have received a copy of the GNU General Public License
	19	+ * along with this program; if not, write to the Free Software
	20	+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	21	+ * MA 02111-1307 USA
	22	+ */
	23	+
	24	+#include <common.h>
	25	+#include <spi.h>
	26	+
	27	+#define SPI_EEPROM_WREN 0x06
	28	+#define SPI_EEPROM_RDSR 0x05
	29	+#define SPI_EEPROM_READ 0x03
	30	+#define SPI_EEPROM_WRITE 0x02
	31	+
	32	+#ifndef CONFIG_DEFAULT_SPI_BUS
	33	+#define CONFIG_DEFAULT_SPI_BUS 0
	34	+#endif
	35	+
	36	+#ifndef CONFIG_DEFAULT_SPI_MODE
	37	+#define CONFIG_DEFAULT_SPI_MODE SPI_MODE_0
	38	+#endif
	39	+
	40	+ssize_t spi_read (uchar addr, int alen, uchar buffer, int len)
	41	+{
	42	+ struct spi_slave *slave;
	43	+ u8 cmd = SPI_EEPROM_READ;
	44	+
	45	+ slave = spi_setup_slave(CONFIG_DEFAULT_SPI_BUS, 1, 1000000,
	46	+ CONFIG_DEFAULT_SPI_MODE);
	47	+ spi_claim_bus(slave);
	48	+
	49	+ /* command */
	50	+ if(spi_xfer(slave, 8, &cmd, NULL, SPI_XFER_BEGIN))
	51	+ return -1;
	52	+
	53	+ /*
	54	+ * if alen == 3, addr[0] is the block number, we never use it here. All we
	55	+ * need are the lower 16 bits
	56	+ */
	57	+ if (alen == 3)
	58	+ addr++;
	59	+
	60	+ /* address, and data */
	61	+ if(spi_xfer(slave, 16, addr, NULL, 0))
	62	+ return -1;
	63	+ if(spi_xfer(slave, 8 * len, NULL, buffer, SPI_XFER_END))
	64	+ return -1;
	65	+
	66	+ spi_release_bus(slave);
	67	+ spi_free_slave(slave);
	68	+ return len;
	69	+}
	70	+
	71	+ssize_t spi_write (uchar addr, int alen, uchar buffer, int len)
	72	+{
	73	+ struct spi_slave *slave;
	74	+ int i;
	75	+ char buf[3];
	76	+
	77	+ slave = spi_setup_slave(CONFIG_DEFAULT_SPI_BUS, 1, 1000000,
	78	+ CONFIG_DEFAULT_SPI_MODE);
	79	+ spi_claim_bus(slave);
	80	+
	81	+ buf[0] = SPI_EEPROM_WREN;
	82	+ if(spi_xfer(slave, 8, buf, NULL, SPI_XFER_BEGIN \| SPI_XFER_END))
	83	+ return -1;
	84	+
	85	+ buf[0] = SPI_EEPROM_WRITE;
	86	+
	87	+ /* As for reading, drop addr[0] if alen is 3 */
	88	+ if (alen == 3) {
	89	+ alen--;
	90	+ addr++;
	91	+ }
	92	+
	93	+ memcpy(buf + 1, addr, alen);
	94	+ /* command + addr, then data */
	95	+ if(spi_xfer(slave, 24, buf, NULL, SPI_XFER_BEGIN))
	96	+ return -1;
	97	+ if(spi_xfer(slave, len * 8, buffer, NULL, SPI_XFER_END))
	98	+ return -1;
	99	+
	100	+ reset_timer_masked();
	101	+ do {
	102	+ buf[0] = SPI_EEPROM_RDSR;
	103	+ buf[1] = 0;
	104	+ spi_xfer(slave, 16, buf, buf, SPI_XFER_BEGIN \| SPI_XFER_END);
	105	+
	106	+ if (!(buf[1] & 1))
	107	+ break;
	108	+
	109	+ } while (get_timer_masked() < CONFIG_SYS_SPI_WRITE_TOUT);
	110	+
	111	+ if (buf[1] & 1)
	112	+ printf ("*** spi_write: Time out while writing!\n");
	113	+
	114	+ spi_release_bus(slave);
	115	+ spi_free_slave(slave);
	116	+ return len;
	117	+}