diff options
Diffstat (limited to 'arch/mips/tx4938/toshiba_rbtx4938/spi_eeprom.c')
| -rw-r--r-- | arch/mips/tx4938/toshiba_rbtx4938/spi_eeprom.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/arch/mips/tx4938/toshiba_rbtx4938/spi_eeprom.c b/arch/mips/tx4938/toshiba_rbtx4938/spi_eeprom.c new file mode 100644 index 0000000..951a208 --- /dev/null +++ b/arch/mips/tx4938/toshiba_rbtx4938/spi_eeprom.c @@ -0,0 +1,219 @@ +/* + * linux/arch/mips/tx4938/toshiba_rbtx4938/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/config.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/proc_fs.h> +#include <linux/spinlock.h> +#include <asm/tx4938/spi.h> +#include <asm/tx4938/tx4938.h> + +/* ATMEL 250x0 instructions */ +#define ATMEL_WREN 0x06 +#define ATMEL_WRDI 0x04 +#define ATMEL_RDSR 0x05 +#define ATMEL_WRSR 0x01 +#define ATMEL_READ 0x03 +#define ATMEL_WRITE 0x02 + +#define ATMEL_SR_BSY 0x01 +#define ATMEL_SR_WEN 0x02 +#define ATMEL_SR_BP0 0x04 +#define ATMEL_SR_BP1 0x08 + +DEFINE_SPINLOCK(spi_eeprom_lock); + +static struct spi_dev_desc seeprom_dev_desc = { + .baud = 1500000, /* 1.5Mbps */ + .tcss = 1, + .tcsh = 1, + .tcsr = 1, + .byteorder = 1, /* MSB-First */ + .polarity = 0, /* High-Active */ + .phase = 0, /* Sample-Then-Shift */ + +}; +static inline int +spi_eeprom_io(int chipid, + unsigned char **inbufs, unsigned int *incounts, + unsigned char **outbufs, unsigned int *outcounts) +{ + return txx9_spi_io(chipid, &seeprom_dev_desc, + inbufs, incounts, outbufs, outcounts, 0); +} + +int spi_eeprom_write_enable(int chipid, int enable) +{ + unsigned char inbuf[1]; + unsigned char *inbufs[1]; + unsigned int incounts[2]; + unsigned long flags; + int stat; + inbuf[0] = enable ? ATMEL_WREN : ATMEL_WRDI; + inbufs[0] = inbuf; + incounts[0] = sizeof(inbuf); + incounts[1] = 0; + spin_lock_irqsave(&spi_eeprom_lock, flags); + stat = spi_eeprom_io(chipid, inbufs, incounts, NULL, NULL); + spin_unlock_irqrestore(&spi_eeprom_lock, flags); + return stat; +} + +static int spi_eeprom_read_status_nolock(int chipid) +{ + unsigned char inbuf[2], outbuf[2]; + unsigned char *inbufs[1], *outbufs[1]; + unsigned int incounts[2], outcounts[2]; + int stat; + inbuf[0] = ATMEL_RDSR; + inbuf[1] = 0; + inbufs[0] = inbuf; + incounts[0] = sizeof(inbuf); + incounts[1] = 0; + outbufs[0] = outbuf; + outcounts[0] = sizeof(outbuf); + outcounts[1] = 0; + stat = spi_eeprom_io(chipid, inbufs, incounts, outbufs, outcounts); + if (stat < 0) + return stat; + return outbuf[1]; +} + +int spi_eeprom_read_status(int chipid) +{ + unsigned long flags; + int stat; + spin_lock_irqsave(&spi_eeprom_lock, flags); + stat = spi_eeprom_read_status_nolock(chipid); + spin_unlock_irqrestore(&spi_eeprom_lock, flags); + return stat; +} + +int spi_eeprom_read(int chipid, int address, unsigned char *buf, int len) +{ + unsigned char inbuf[2]; + unsigned char *inbufs[2], *outbufs[2]; + unsigned int incounts[2], outcounts[3]; + unsigned long flags; + int stat; + inbuf[0] = ATMEL_READ; + inbuf[1] = address; + inbufs[0] = inbuf; + inbufs[1] = NULL; + incounts[0] = sizeof(inbuf); + incounts[1] = 0; + outbufs[0] = NULL; + outbufs[1] = buf; + outcounts[0] = 2; + outcounts[1] = len; + outcounts[2] = 0; + spin_lock_irqsave(&spi_eeprom_lock, flags); + stat = spi_eeprom_io(chipid, inbufs, incounts, outbufs, outcounts); + spin_unlock_irqrestore(&spi_eeprom_lock, flags); + return stat; +} + +int spi_eeprom_write(int chipid, int address, unsigned char *buf, int len) +{ + unsigned char inbuf[2]; + unsigned char *inbufs[2]; + unsigned int incounts[3]; + unsigned long flags; + int i, stat; + + if (address / 8 != (address + len - 1) / 8) + return -EINVAL; + stat = spi_eeprom_write_enable(chipid, 1); + if (stat < 0) + return stat; + stat = spi_eeprom_read_status(chipid); + if (stat < 0) + return stat; + if (!(stat & ATMEL_SR_WEN)) + return -EPERM; + + inbuf[0] = ATMEL_WRITE; + inbuf[1] = address; + inbufs[0] = inbuf; + inbufs[1] = buf; + incounts[0] = sizeof(inbuf); + incounts[1] = len; + incounts[2] = 0; + spin_lock_irqsave(&spi_eeprom_lock, flags); + stat = spi_eeprom_io(chipid, inbufs, incounts, NULL, NULL); + if (stat < 0) + goto unlock_return; + + /* write start. max 10ms */ + for (i = 10; i > 0; i--) { + int stat = spi_eeprom_read_status_nolock(chipid); + if (stat < 0) + goto unlock_return; + if (!(stat & ATMEL_SR_BSY)) + break; + mdelay(1); + } + spin_unlock_irqrestore(&spi_eeprom_lock, flags); + if (i == 0) + return -EIO; + return len; + unlock_return: + spin_unlock_irqrestore(&spi_eeprom_lock, flags); + return stat; +} + +#ifdef CONFIG_PROC_FS +#define MAX_SIZE 0x80 /* for ATMEL 25010 */ +static int spi_eeprom_read_proc(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + unsigned int size = MAX_SIZE; + if (spi_eeprom_read((int)data, 0, (unsigned char *)page, size) < 0) + size = 0; + return size; +} + +static int spi_eeprom_write_proc(struct file *file, const char *buffer, + unsigned long count, void *data) +{ + unsigned int size = MAX_SIZE; + int i; + if (file->f_pos >= size) + return -EIO; + if (file->f_pos + count > size) + count = size - file->f_pos; + for (i = 0; i < count; i += 8) { + int len = count - i < 8 ? count - i : 8; + if (spi_eeprom_write((int)data, file->f_pos, + (unsigned char *)buffer, len) < 0) { + count = -EIO; + break; + } + buffer += len; + file->f_pos += len; + } + return count; +} + +__init void spi_eeprom_proc_create(struct proc_dir_entry *dir, int chipid) +{ + struct proc_dir_entry *entry; + char name[128]; + sprintf(name, "seeprom-%d", chipid); + entry = create_proc_entry(name, 0600, dir); + if (entry) { + entry->read_proc = spi_eeprom_read_proc; + entry->write_proc = spi_eeprom_write_proc; + entry->data = (void *)chipid; + } +} +#endif /* CONFIG_PROC_FS */ |
