aboutsummaryrefslogtreecommitdiff
path: root/arch/mips/txx9/generic/spi_eeprom.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/txx9/generic/spi_eeprom.c')
-rw-r--r--arch/mips/txx9/generic/spi_eeprom.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/mips/txx9/generic/spi_eeprom.c b/arch/mips/txx9/generic/spi_eeprom.c
new file mode 100644
index 00000000000..75c347238f4
--- /dev/null
+++ b/arch/mips/txx9/generic/spi_eeprom.c
@@ -0,0 +1,103 @@
+/*
+ * 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 busid, int chipid, int size)
+{
+ struct spi_board_info info = {
+ .modalias = "at25",
+ .max_speed_hz = 1500000, /* 1.5Mbps */
+ .bus_num = busid,
+ .chip_select = chipid,
+ /* Mode 0: High-Active, Sample-Then-Shift */
+ };
+ struct spi_eeprom *eeprom;
+ eeprom = kzalloc(sizeof(*eeprom), GFP_KERNEL);
+ if (!eeprom)
+ return -ENOMEM;
+ strcpy(eeprom->name, "at250x0");
+ eeprom->byte_len = size;
+ eeprom->page_size = AT250X0_PAGE_SIZE;
+ eeprom->flags = EE_ADDR1;
+ info.platform_data = eeprom;
+ return spi_register_board_info(&info, 1);
+}
+
+/* simple temporary spi driver to provide early access to seeprom. */
+
+static struct read_param {
+ int busid;
+ 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->busid != spi->master->bus_num ||
+ 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 busid, int chipid, int address,
+ unsigned char *buf, int len)
+{
+ int ret;
+ struct read_param param = {
+ .busid = busid,
+ .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;
+}