/* * Copyright (C) 2004 - 2006 rt2x00 SourceForge 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. * * Module: eeprom_93cx6 * Abstract: EEPROM reader routines for 93cx6 chipsets. * Supported chipsets: 93c46 & 93c66. */ #include #include #include #include MODULE_AUTHOR("http://rt2x00.serialmonkey.com"); MODULE_VERSION("1.0"); MODULE_DESCRIPTION("EEPROM 93cx6 chip driver"); MODULE_LICENSE("GPL"); static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom) { eeprom->reg_data_clock = 1; eeprom->register_write(eeprom); /* * Add a short delay for the pulse to work. * According to the specifications the "maximum minimum" * time should be 450ns. */ ndelay(450); } static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom) { eeprom->reg_data_clock = 0; eeprom->register_write(eeprom); /* * Add a short delay for the pulse to work. * According to the specifications the "maximum minimum" * time should be 450ns. */ ndelay(450); } static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom) { /* * Clear all flags, and enable chip select. */ eeprom->register_read(eeprom); eeprom->reg_data_in = 0; eeprom->reg_data_out = 0; eeprom->reg_data_clock = 0; eeprom->reg_chip_select = 1; eeprom->drive_data = 1; eeprom->register_write(eeprom); /* * kick a pulse. */ eeprom_93cx6_pulse_high(eeprom); eeprom_93cx6_pulse_low(eeprom); } static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom) { /* * Clear chip_select and data_in flags. */ eeprom->register_read(eeprom); eeprom->reg_data_in = 0; eeprom->reg_chip_select = 0; eeprom->register_write(eeprom); /* * kick a pulse. */ eeprom_93cx6_pulse_high(eeprom); eeprom_93cx6_pulse_low(eeprom); } static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom, const u16 data, const u16 count) { unsigned int i; eeprom->register_read(eeprom); /* * Clear data flags. */ eeprom->reg_data_in = 0; eeprom->reg_data_out = 0; eeprom->drive_data = 1; /* * Start writing all bits. */ for (i = count; i > 0; i--) { /* * Check if this bit needs to be set. */ eeprom->reg_data_in = !!(data & (1 << (i - 1))); /* * Write the bit to the eeprom register. */ eeprom->register_write(eeprom); /* * Kick a pulse. */ eeprom_93cx6_pulse_high(eeprom); eeprom_93cx6_pulse_low(eeprom); } eeprom->reg_data_in = 0; eeprom->register_write(eeprom); } static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom, u16 *data, const u16 count) { unsigned int i; u16 buf = 0; eeprom->register_read(eeprom); /* * Clear data flags. */ eeprom->reg_data_in = 0; eeprom->reg_data_out = 0; eeprom->drive_data = 0; /* * Start reading all bits. */ for (i = count; i > 0; i--) { eeprom_93cx6_pulse_high(eeprom); eeprom->register_read(eeprom); /* * Clear data_in flag. */ eeprom->reg_data_in = 0; /* * Read if the bit has been set. */ if (eeprom->reg_data_out) buf |= (1 << (i - 1)); eeprom_93cx6_pulse_low(eeprom); } *data = buf; } /** * eeprom_93cx6_read - Read multiple words from eeprom * @eeprom: Pointer to eeprom structure * @word: Word index from where we should start reading * @data: target pointer where the information will have to be stored * * This function will read the eeprom data as host-endian word * into the given data pointer. */ void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word, u16 *data) { u16 command; /* * Initialize the eeprom register */ eeprom_93cx6_startup(eeprom); /* * Select the read opcode and the word to be read. */ command = (PCI_EEPROM_READ_OPCODE << eeprom->width) | word; eeprom_93cx6_write_bits(eeprom, command, PCI_EEPROM_WIDTH_OPCODE + eeprom->width); /* * Read the requested 16 bits. */ eeprom_93cx6_read_bits(eeprom, data, 16); /* * Cleanup eeprom register. */ eeprom_93cx6_cleanup(eeprom); } EXPORT_SYMBOL_GPL(eeprom_93cx6_read); /** * eeprom_93cx6_multiread - Read multiple words from eeprom * @eeprom: Pointer to eeprom structure * @word: Word index from where we should start reading * @data: target pointer where the information will have to be stored * @words: Number of words that should be read. * * This function will read all requested words from the eeprom, * this is done by calling eeprom_93cx6_read() multiple times. * But with the additional change that while the eeprom_93cx6_read * will return host ordered bytes, this method will return little * endian words. */ void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word, __le16 *data, const u16 words) { unsigned int i; u16 tmp; for (i = 0; i < words; i++) { tmp = 0; eeprom_93cx6_read(eeprom, word + i, &tmp); data[i] = cpu_to_le16(tmp); } } EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread); /** * eeprom_93cx6_wren - set the write enable state * @eeprom: Pointer to eeprom structure * @enable: true to enable writes, otherwise disable writes * * Set the EEPROM write enable state to either allow or deny * writes depending on the @enable value. */ void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable) { u16 command; /* start the command */ eeprom_93cx6_startup(eeprom); /* create command to enable/disable */ command = enable ? PCI_EEPROM_EWEN_OPCODE : PCI_EEPROM_EWDS_OPCODE; command <<= (eeprom->width - 2); eeprom_93cx6_write_bits(eeprom, command, PCI_EEPROM_WIDTH_OPCODE + eeprom->width); eeprom_93cx6_cleanup(eeprom); } EXPORT_SYMBOL_GPL(eeprom_93cx6_wren); /** * eeprom_93cx6_write - write data to the EEPROM * @eeprom: Pointer to eeprom structure * @addr: Address to write data to. * @data: The data to write to address @addr. * * Write the @data to the specified @addr in the EEPROM and * waiting for the device to finish writing. * * Note, since we do not expect large number of write operations * we delay in between parts of the operation to avoid using excessive * amounts of CPU time busy waiting. */ void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom, u8 addr, u16 data) { int timeout = 100; u16 command; /* start the command */ eeprom_93cx6_startup(eeprom); command = PCI_EEPROM_WRITE_OPCODE << eeprom->width; command |= addr; /* send write command */ eeprom_93cx6_write_bits(eeprom, command, PCI_EEPROM_WIDTH_OPCODE + eeprom->width); /* send data */ eeprom_93cx6_write_bits(eeprom, data, 16); /* get ready to check for busy */ eeprom->drive_data = 0; eeprom->reg_chip_select = 1; eeprom->register_write(eeprom); /* wait at-least 250ns to get DO to be the busy signal */ usleep_range(1000, 2000); /* wait for DO to go high to signify finish */ while (true) { eeprom->register_read(eeprom); if (eeprom->reg_data_out) break; usleep_range(1000, 2000); if (--timeout <= 0) { printk(KERN_ERR "%s: timeout\n", __func__); break; } } eeprom_93cx6_cleanup(eeprom); } EXPORT_SYMBOL_GPL(eeprom_93cx6_write);