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Diffstat (limited to 'arch/mips/txx9/rbtx4938/spi_eeprom.c')
-rw-r--r--arch/mips/txx9/rbtx4938/spi_eeprom.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/arch/mips/txx9/rbtx4938/spi_eeprom.c b/arch/mips/txx9/rbtx4938/spi_eeprom.c
new file mode 100644
index 0000000..a7ea8b0
--- /dev/null
+++ b/arch/mips/txx9/rbtx4938/spi_eeprom.c
@@ -0,0 +1,99 @@
+/*
+ * spi_eeprom.c
+ * Copyright (C) 2000-2001 Toshiba Corporation
+ *
+ * 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
+ * terms of the GNU General Public License version 2. This program is
+ * licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ *
+ * Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
+ */
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/eeprom.h>
+#include <asm/txx9/spi.h>
+
+#define AT250X0_PAGE_SIZE 8
+
+/* register board information for at25 driver */
+int __init spi_eeprom_register(int chipid)
+{
+ static struct spi_eeprom eeprom = {
+ .name = "at250x0",
+ .byte_len = 128,
+ .page_size = AT250X0_PAGE_SIZE,
+ .flags = EE_ADDR1,
+ };
+ struct spi_board_info info = {
+ .modalias = "at25",
+ .max_speed_hz = 1500000, /* 1.5Mbps */
+ .bus_num = 0,
+ .chip_select = chipid,
+ .platform_data = &eeprom,
+ /* Mode 0: High-Active, Sample-Then-Shift */
+ };
+
+ return spi_register_board_info(&info, 1);
+}
+
+/* simple temporary spi driver to provide early access to seeprom. */
+
+static struct read_param {
+ int chipid;
+ int address;
+ unsigned char *buf;
+ int len;
+} *read_param;
+
+static int __init early_seeprom_probe(struct spi_device *spi)
+{
+ int stat = 0;
+ u8 cmd[2];
+ int len = read_param->len;
+ char *buf = read_param->buf;
+ int address = read_param->address;
+
+ dev_info(&spi->dev, "spiclk %u KHz.\n",
+ (spi->max_speed_hz + 500) / 1000);
+ if (read_param->chipid != spi->chip_select)
+ return -ENODEV;
+ while (len > 0) {
+ /* spi_write_then_read can only work with small chunk */
+ int c = len < AT250X0_PAGE_SIZE ? len : AT250X0_PAGE_SIZE;
+ cmd[0] = 0x03; /* AT25_READ */
+ cmd[1] = address;
+ stat = spi_write_then_read(spi, cmd, sizeof(cmd), buf, c);
+ buf += c;
+ len -= c;
+ address += c;
+ }
+ return stat;
+}
+
+static struct spi_driver early_seeprom_driver __initdata = {
+ .driver = {
+ .name = "at25",
+ .owner = THIS_MODULE,
+ },
+ .probe = early_seeprom_probe,
+};
+
+int __init spi_eeprom_read(int chipid, int address,
+ unsigned char *buf, int len)
+{
+ int ret;
+ struct read_param param = {
+ .chipid = chipid,
+ .address = address,
+ .buf = buf,
+ .len = len
+ };
+
+ read_param = &param;
+ ret = spi_register_driver(&early_seeprom_driver);
+ if (!ret)
+ spi_unregister_driver(&early_seeprom_driver);
+ return ret;
+}
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